feat(middleware): introduce withAuth Next.js method (#3657)

* feat(middleware): introduce Middleware API to Next.js

* chore(app): upgrade Next.js in dev app

* chore(dev): add Middleware protected page to dev app

* chore(middleware): add `next/middleware` to `exports`

* fix(middleware): bail out redirect on custom pages

* fix(middleware): allow one-line export

* chore(middleware): simplify code

* fix(middleware): redirect back to page after succesful login

* feat(middleware): re-export `withAuth` as `default`

* chore: export middleware from `next-auth/middleware`

* chore: add `middleware` files to npm

* feat(middleware): handle chaining, fix some bugs

* chore(dev): showcase different middlewares

* chore(middleware): remove `@ts-expect-error` comments

* chore: update build clean script

* fix: bail out when NextAuth.js paths

* refactor: be more explicit about `initConfig` result

* refactor: simplify

* refactor: use `callbacks` similarily to `NextAuthOptions`

* refactor: use `nextauth` namespace when setting `token` on `req`

* refactor: don't allow passing `secret`

* addressing review

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -10,7 +10,18 @@ body:
   - type: markdown
     attributes:
       value: |
-        Thanks for taking the time to fill out this bug report! Please provide the following information:
+        Thanks for taking the time to fill out this bug report!
+        ### Important :exclamation:
+        Please help us maintain this project more efficiently!
+        Is this your first time contributing? See this video https://www.youtube.com/watch?v=cuoNzXFLitc
+        
+        **Providing incorrect/insufficient information or skipping steps to reproduce the bug may result in closing the issue or converting to discussion without further explanation.**
+        
+        Before creating the issue make sure you shouldn't be creating it in one the below repos instead:
+        - Docs related: https://github.com/nextauthjs/docs
+        - Adapter related: https://github.com/nextauthjs/adapters
+        
+        If you are in the correct repo, then proceed by providing the following information:
   - type: textarea
     id: description
     attributes: 
@@ -44,8 +55,6 @@ body:
         We encourage you to use one of the templates set up on **CodeSandbox** to reproduce your issue:
         - [`next-auth-example`](https://codesandbox.io/s/next-auth-example-1kktb)
         - [`next-auth-typescript-example`](https://codesandbox.io/s/next-auth-typescript-example-se32w)
-
-        🚧 – _If you don't provide any way to reproduce the bug, the issue is at risk of being closed._
   
   - type: textarea
     id: logs

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -9,8 +9,14 @@ body:
   - type: markdown
     attributes:
       value: | 
-        Thank you very much for reaching out to us regarding the awesome feature that you believe should be included in the NextAuth.js library. Please provide the following information:
- 
+        Thank you very much for reaching out to us regarding the awesome feature that you believe should be included in the NextAuth.js library.
+        ### Important :exclamation:
+        Please help us maintain this project more efficiently! Before creating the issue make sure you shouldn't be creating it in one the below repos instead:
+        - Docs related: https://github.com/nextauthjs/docs
+        - Adapter related: https://github.com/nextauthjs/adapters
+        
+        If you are in the correct repo, then proceed by providing the following information:
+  
   - type: textarea
     id: description
     attributes:
@@ -65,4 +71,3 @@ body:
     attributes: 
       value: |
         It takes a lot of work 🏋🏻‍♀️ maintaining a library like `next-auth`; any contribution is more than welcome 💚
-  

.gitignore

@@ -29,12 +29,15 @@ node_modules
 /client
 /css
 /lib
-/server
+/core
 /jwt
 /react
 /adapters.d.ts
 /index.d.ts
 /index.js
+/next
+/middleware.d.ts
+/middleware.js
 
 # Development app
 app/src/css
@@ -42,6 +45,8 @@ app/package-lock.json
 app/yarn.lock
 app/prisma/migrations
 app/prisma/dev.db*
+app/dist
+app/next-auth
 
 # VS
 /.vs/slnx.sqlite-journal
@@ -49,6 +54,9 @@ app/prisma/dev.db*
 /.vs
 .vscode
 
+# Jetbrains
+.idea
+
 # GitHub Actions runner
 /actions-runner
 /_work

README.md

@@ -32,6 +32,11 @@ NextAuth.js is a complete open source authentication solution for [Next.js](http
 
 It is designed from the ground up to support Next.js and Serverless.
 
+This is the core repo for NextAuth.js. Check the repos below if you are interested in additional information:
+
+- Docs related: https://github.com/nextauthjs/docs
+- Adapter related: https://github.com/nextauthjs/adapters
+
 ## Getting Started
 
 ```
@@ -49,7 +54,7 @@ See [next-auth.js.org](https://next-auth.js.org) for more information and docume
 ### Flexible and easy to use
 
 - Designed to work with any OAuth service, it supports OAuth 1.0, 1.0A and 2.0
-- Built-in support for [many popular sign-in services](https://next-auth.js.org/configuration/providers)
+- Built-in support for [many popular sign-in services](https://next-auth.js.org/providers/overview)
 - Supports email / passwordless authentication
 - Supports stateless authentication with any backend (Active Directory, LDAP, etc)
 - Supports both JSON Web Tokens and database sessions
@@ -81,7 +86,8 @@ Advanced options allow you to define your own routines to handle controlling wha
 
 ### TypeScript
 
-NextAuth.js comes with built-in types. For more information and usage, check out the [TypeScript section](https://next-auth.js.org/getting-started/typescript) in the documentation.
+NextAuth.js comes with built-in types. For more information and usage, check out
+the [TypeScript section](https://next-auth.js.org/getting-started/typescript) in the documentation.
 
 ## Example
 
@@ -90,21 +96,24 @@ NextAuth.js comes with built-in types. For more information and usage, check out
 ```javascript
 // pages/api/auth/[...nextauth].js
 import NextAuth from "next-auth"
-import Providers from "next-auth/providers"
+import AppleProvider from "next-auth/providers/apple"
+import GoogleProvider from "next-auth/providers/google"
+import EmailProvider from "next-auth/providers/email"
 
 export default NextAuth({
+  secret: process.env.SECRET,
   providers: [
     // OAuth authentication providers
-    Providers.Apple({
+    AppleProvider({
       clientId: process.env.APPLE_ID,
       clientSecret: process.env.APPLE_SECRET,
     }),
-    Providers.Google({
+    GoogleProvider({
       clientId: process.env.GOOGLE_ID,
       clientSecret: process.env.GOOGLE_SECRET,
     }),
     // Sign in with passwordless email link
-    Providers.Email({
+    EmailProvider({
       server: process.env.MAIL_SERVER,
       from: "<no-reply@example.com>",
     }),
@@ -140,7 +149,7 @@ export default function Component() {
 
 ### Share/configure session state
 
-Use the `<SessionProvider>` to allows instances of `useSession()` to share the session object across components. It also takes care of keeping the session updated and synced between tabs/windows.
+Use the `<SessionProvider>` to allow instances of `useSession()` to share the session object across components. It also takes care of keeping the session updated and synced between tabs/windows.
 
 ```jsx title="pages/_app.js"
 import { SessionProvider } from "next-auth/react"
@@ -170,7 +179,7 @@ export default function App({
 
 ### Support
 
-We're happy to announce we've recently created an [OpenCollective](https://opencollective.org/nextauth) for individuals and companies looking to contribute financially to the project!
+We're happy to announce we've recently created an [OpenCollective](https://opencollective.com/nextauth) for individuals and companies looking to contribute financially to the project!
 
 <!--sponsors start-->
 <table>
@@ -190,6 +199,13 @@ We're happy to announce we've recently created an [OpenCollective](https://openc
         <div>Prisma</div><br />
         <sub>🥉 Bronze Financial Sponsor</sub>
       </td>
+      <td align="center" valign="top">
+        <a href="https://clerk.dev" target="_blank">
+          <img width="128px" src="https://avatars.githubusercontent.com/u/49538330?s=200&v=4" alt="Prisma Logo" />
+        </a><br />
+        <div>Clerk</div><br />
+        <sub>🥉 Bronze Financial Sponsor</sub>
+      </td>
       <td align="center" valign="top">
         <a href="https://checklyhq.com" target="_blank">
           <img width="128px" src="https://avatars.githubusercontent.com/u/25982255?v=4" alt="Checkly Logo" />
@@ -197,6 +213,13 @@ We're happy to announce we've recently created an [OpenCollective](https://openc
         <div>Checkly</div><br />
         <sub>☁️ Infrastructure Support</sub>
       </td>
+      <td align="center" valign="top">
+        <a href="https://superblog.ai/" target="_blank">
+          <img width="128px" src="https://d33wubrfki0l68.cloudfront.net/cdc4a3833bd878933fcc131655878dbf226ac1c5/10cd6/images/logo_bolt_small.png" alt="superblog Logo" />
+        </a><br />
+        <div>superblog</div><br />
+        <sub>☁️ Infrastructure Support</sub>
+      </td>
     </tr><tr></tr>
   </tbody>
 </table>
@@ -205,7 +228,8 @@ We're happy to announce we've recently created an [OpenCollective](https://openc
 
 ## Contributing
 
-We're open to all community contributions! If you'd like to contribute in any way, please first read our [Contributing Guide](https://github.com/nextauthjs/next-auth/blob/canary/CONTRIBUTING.md).
+We're open to all community contributions! If you'd like to contribute in any way, please first read
+our [Contributing Guide](https://github.com/nextauthjs/next-auth/blob/main/CONTRIBUTING.md).
 
 ## License
 

SECURITY.md

@@ -2,12 +2,6 @@
 
 NextAuth.js practices responsible disclosure.
 
-## Supported Versions
-
-Security updates are only released for the current version.
-
-Old releases are not maintained and do not receive updates.
-
 ## Reporting a Vulnerability
 
 We request that you contact us directly to report serious issues that might impact the security of sites using NextAuth.js.
@@ -19,6 +13,12 @@ If you contact us regarding a serious issue:
 - We will disclose the issue (and credit you, with your consent) once a fix to resolve the issue has been released.
 - If 90 days has elapsed and we still don't have a fix, we will disclose the issue publicly.
 
-Currently, the best way to report an issue is by contacting us via email at me@iaincollins.com or info@balazsorban.com and yo@ndo.dev.
+The best way to report an issue is by contacting us via email at info@balazsorban.com or me@iaincollins.com and yo@ndo.dev, or raise a public issue requesting someone get in touch with you via whatever means you prefer for more details. (Please do not disclose sensitive details publicly at this stage.)
 
-For less serious issues (e.g. RFC compliance for unsupported flows or potential issues that may cause a problem future or default behaviour / options) it is appropriate to submit these these publically as bug reports or feature requests or to raise a question to open a discussion around them.
+> For less serious issues (e.g. RFC compliance for unsupported flows or potential issues that may cause a problem in the future) it is appropriate to submit these these publically as bug reports or feature requests or to raise a question to open a discussion around them.
+
+## Supported Versions
+
+Security updates are only released for the current version.
+
+Old releases are not maintained and do not receive updates.

app/.env.local.example

@@ -7,7 +7,7 @@ NEXTAUTH_URL=http://localhost:3000
 # https://generate-secret.vercel.app/32 to generate a secret.
 # Note: Changing a secret may invalidate existing sessions
 # and/or verification tokens.
-SECRET=secret
+NEXTAUTH_SECRET=secret
 
 AUTH0_ID=
 AUTH0_SECRET=
@@ -30,6 +30,12 @@ TWITCH_SECRET=
 TWITTER_ID=
 TWITTER_SECRET=
 
+LINE_ID=
+LINE_SECRET=
+
+TRAKT_ID=
+TRAKT_SECRET=
+
 # Example configuration for a Gmail account (will need SMTP enabled)
 EMAIL_SERVER=smtps://user@gmail.com:password@smtp.gmail.com:465
 EMAIL_FROM=user@gmail.com

app/components/header.js

@@ -39,15 +39,13 @@ export default function Header() {
           {session && (
             <>
               {session.user.image && (
-                <span
-                  style={{ backgroundImage: `url(${session.user.image})` }}
-                  className={styles.avatar}
-                />
+                <img src={session.user.image} className={styles.avatar} />
               )}
               <span className={styles.signedInText}>
                 <small>Signed in as</small>
                 <br />
-                <strong>{session.user.email || session.user.name}</strong>
+                <strong>{session.user.email} </strong>
+                {session.user.name ? `(${session.user.name})` : null}
               </span>
               <a
                 href="/api/auth/signout"
@@ -105,6 +103,11 @@ export default function Header() {
               <a>Email</a>
             </Link>
           </li>
+          <li className={styles.navItem}>
+            <Link href="/middleware-protected">
+              <a>Middleware protected</a>
+            </Link>
+          </li>
         </ul>
       </nav>
     </header>

app/next-env.d.ts

@@ -1,5 +1,4 @@
 /// <reference types="next" />
-/// <reference types="next/types/global" />
 /// <reference types="next/image-types/global" />
 
 // NOTE: This file should not be edited

app/next.config.js

@@ -2,6 +2,10 @@ const path = require("path")
 
 module.exports = {
   webpack(config) {
+    config.experiments = {
+      ...config.experiments,
+      topLevelAwait: true,
+    }
     config.resolve = {
       ...config.resolve,
       alias: {
@@ -18,6 +22,9 @@ module.exports = {
 
     return config
   },
+  typescript: {
+    ignoreBuildErrors: true,
+  },
   experimental: {
     externalDir: true,
   },

app/package.json

@@ -5,28 +5,31 @@
   "private": true,
   "scripts": {
     "clean": "rm -rf .next",
+    "postinstall": "rm -rf node_modules/next-auth",
     "dev": "npm-run-all --parallel dev:next watch:css copy:css ",
     "dev:next": "next dev",
+    "build": "next build",
     "copy:css": "cpx \"../css/**/*\" src/css --watch",
     "watch:css": "cd .. && npm run watch:css",
     "start": "next start",
-    "start:email": "npx fake-smtp-server"
+    "email": "npx fake-smtp-server",
+    "start:email": "npm run email"
   },
   "license": "ISC",
   "dependencies": {
-    "@next-auth/fauna-adapter": "0.2.2-next.4",
-    "@next-auth/prisma-adapter": "0.5.2-next.5",
-    "@prisma/client": "^2.29.1",
+    "@next-auth/fauna-adapter": "^1.0.1",
+    "@next-auth/prisma-adapter": "^1.0.1",
+    "@prisma/client": "^3.7.0",
     "fake-smtp-server": "^0.8.0",
-    "faunadb": "^4.3.0",
-    "next": "^11.1.0",
-    "nodemailer": "^6.6.3",
+    "faunadb": "^4.4.1",
+    "next": "^12.0.8",
+    "nodemailer": "^6.7.2",
     "react": "^17.0.2",
     "react-dom": "^17.0.2"
   },
   "devDependencies": {
     "cpx": "^1.5.0",
     "npm-run-all": "^4.1.5",
-    "prisma": "^2.29.1"
+    "prisma": "^3.7.0"
   }
 }

app/pages/_app.js

@@ -1,12 +1,9 @@
 import { SessionProvider } from "next-auth/react"
 import "./styles.css"
 
-export default function App({
-  Component,
-  pageProps: { session, ...pageProps },
-}) {
+export default function App({ Component, pageProps }) {
   return (
-    <SessionProvider session={session}>
+    <SessionProvider session={pageProps.session}>
       <Component {...pageProps} />
     </SessionProvider>
   )

app/pages/api/auth/[...nextauth].ts

@@ -1,9 +1,11 @@
-import NextAuth from "next-auth"
-import EmailProvider from "next-auth/providers/email"
+import NextAuth, { NextAuthOptions } from "next-auth"
+// import EmailProvider from "next-auth/providers/email"
 import GitHubProvider from "next-auth/providers/github"
 import Auth0Provider from "next-auth/providers/auth0"
 import KeycloakProvider from "next-auth/providers/keycloak"
-import TwitterProvider from "next-auth/providers/twitter"
+import TwitterProvider, {
+  TwitterLegacy as TwitterLegacyProvider,
+} from "next-auth/providers/twitter"
 import CredentialsProvider from "next-auth/providers/credentials"
 import IDS4Provider from "next-auth/providers/identity-server4"
 import Twitch from "next-auth/providers/twitch"
@@ -17,6 +19,16 @@ import LineProvider from "next-auth/providers/line"
 import LinkedInProvider from "next-auth/providers/linkedin"
 import MailchimpProvider from "next-auth/providers/mailchimp"
 import DiscordProvider from "next-auth/providers/discord"
+import AzureADProvider from "next-auth/providers/azure-ad"
+import SpotifyProvider from "next-auth/providers/spotify"
+import CognitoProvider from "next-auth/providers/cognito"
+import SlackProvider from "next-auth/providers/slack"
+import Okta from "next-auth/providers/okta"
+import AzureB2C from "next-auth/providers/azure-ad-b2c"
+import OsuProvider from "next-auth/providers/osu"
+import AppleProvider from "next-auth/providers/apple"
+import PatreonProvider from "next-auth/providers/patreon"
+import TraktProvider from "next-auth/providers/trakt"
 
 // import { PrismaAdapter } from "@next-auth/prisma-adapter"
 // import { PrismaClient } from "@prisma/client"
@@ -31,29 +43,28 @@ import DiscordProvider from "next-auth/providers/discord"
 //   domain: process.env.FAUNA_DOMAIN,
 // })
 // const adapter = FaunaAdapter(client)
-
-export default NextAuth({
+export const authOptions: NextAuthOptions = {
   // adapter,
   providers: [
     // E-mail
     // Start fake e-mail server with `npm run start:email`
-    EmailProvider({
-      server: {
-        host: "127.0.0.1",
-        auth: null,
-        secure: false,
-        port: 1025,
-        tls: { rejectUnauthorized: false },
-      },
-    }),
+    // EmailProvider({
+    //   server: {
+    //     host: "127.0.0.1",
+    //     auth: null,
+    //     secure: false,
+    //     port: 1025,
+    //     tls: { rejectUnauthorized: false },
+    //   },
+    // }),
     // Credentials
     CredentialsProvider({
       name: "Credentials",
       credentials: {
         password: { label: "Password", type: "password" },
       },
-      async authorize(credentials, req) {
-        if (credentials.password === "password") {
+      async authorize(credentials) {
+        if (credentials.password === "pw") {
           return {
             name: "Fill Murray",
             email: "bill@fillmurray.com",
@@ -64,11 +75,17 @@ export default NextAuth({
       },
     }),
     // OAuth 1
+    // TwitterLegacyProvider({
+    //   clientId: process.env.TWITTER_LEGACY_ID,
+    //   clientSecret: process.env.TWITTER_LEGACY_SECRET,
+    // }),
+    // OAuth 2 / OIDC
     TwitterProvider({
+      // Opt-in to the new Twitter API for now. Should be default in the future.
+      version: "2.0",
       clientId: process.env.TWITTER_ID,
       clientSecret: process.env.TWITTER_SECRET,
     }),
-    // OAuth 2 / OIDC
     GitHubProvider({
       clientId: process.env.GITHUB_ID,
       clientSecret: process.env.GITHUB_SECRET,
@@ -132,11 +149,59 @@ export default NextAuth({
       clientId: process.env.DISCORD_ID,
       clientSecret: process.env.DISCORD_SECRET,
     }),
+    AzureADProvider({
+      clientId: process.env.AZURE_AD_CLIENT_ID,
+      clientSecret: process.env.AZURE_AD_CLIENT_SECRET,
+      tenantId: process.env.AZURE_AD_TENANT_ID,
+      profilePhotoSize: 48,
+    }),
+    SpotifyProvider({
+      clientId: process.env.SPOTIFY_ID,
+      clientSecret: process.env.SPOTIFY_SECRET,
+    }),
+    CognitoProvider({
+      clientId: process.env.COGNITO_ID,
+      clientSecret: process.env.COGNITO_SECRET,
+      issuer: process.env.COGNITO_ISSUER,
+    }),
+    Okta({
+      clientId: process.env.OKTA_ID,
+      clientSecret: process.env.OKTA_SECRET,
+      issuer: process.env.OKTA_ISSUER,
+    }),
+    SlackProvider({
+      clientId: process.env.SLACK_ID,
+      clientSecret: process.env.SLACK_SECRET,
+    }),
+    AzureB2C({
+      clientId: process.env.AZURE_B2C_ID,
+      clientSecret: process.env.AZURE_B2C_SECRET,
+      tenantId: process.env.AZURE_B2C_TENANT_ID,
+      primaryUserFlow: process.env.AZURE_B2C_PRIMARY_USER_FLOW,
+    }),
+    OsuProvider({
+      clientId: process.env.OSU_CLIENT_ID,
+      clientSecret: process.env.OSU_CLIENT_SECRET,
+    }),
+    AppleProvider({
+      clientId: process.env.APPLE_ID,
+      clientSecret: process.env.APPLE_SECRET,
+    }),
+    PatreonProvider({
+      clientId: process.env.PATREON_ID,
+      clientSecret: process.env.PATREON_SECRET,
+    }),
+    TraktProvider({
+      clientId: process.env.TRAKT_ID,
+      clientSecret: process.env.TRAKT_SECRET,
+    }),
   ],
-  jwt: {
-    encryption: true,
-    secret: process.env.SECRET,
-  },
   debug: true,
-  theme: "auto",
-})
+  theme: {
+    colorScheme: "auto",
+    logo: "https://next-auth.js.org/img/logo/logo-sm.png",
+    brandColor: "#1786fb",
+  },
+}
+
+export default NextAuth(authOptions)

app/pages/api/examples/jwt.js

@@ -1,9 +1,7 @@
 // This is an example of how to read a JSON Web Token from an API route
-import jwt from "next-auth/jwt"
-
-const secret = process.env.SECRET
+import { getToken } from "next-auth/jwt"
 
 export default async (req, res) => {
-  const token = await jwt.getToken({ req, secret, encryption: true })
+  const token = await getToken({ req, secret: process.env.SECRET })
   res.send(JSON.stringify(token, null, 2))
 }

app/pages/middleware-protected/_middleware.js

@@ -0,0 +1,44 @@
+export { default } from "next-auth/middleware"
+
+// Other ways to use this middleware
+
+// import withAuth from "next-auth/middleware"
+// import { withAuth } from "next-auth/middleware"
+
+// export function middleware(req, ev) {
+//   return withAuth(req)
+// }
+
+// export function middleware(req, ev) {
+//   return withAuth(req, ev)
+// }
+
+// export function middleware(req, ev) {
+//   return withAuth(req, {
+//     callbacks: {
+//       authorized: ({ token }) => !!token,
+//     },
+//   })
+// }
+
+// export default withAuth(function middleware(req, ev) {
+//   console.log(req.nextauth.token)
+// })
+
+// export default withAuth(
+//   function middleware(req, ev) {
+//     console.log(req, ev)
+//     return undefined // NOTE: `NextMiddleware` should allow returning `void`
+//   },
+//   {
+//     callbacks: {
+//       authorized: ({ token }) => token.name === "Balázs Orbán",
+//     }
+//   }
+// )
+
+// export default withAuth({
+//   callbacks: {
+//     authorized: ({ token }) => !!token,
+//   },
+// })

app/pages/middleware-protected/index.js

@@ -0,0 +1,9 @@
+import Layout from "components/layout"
+
+export default function Page() {
+  return (
+    <Layout>
+      <h1>Page protected by Middleware</h1>
+    </Layout>
+  )
+}

app/pages/protected-ssr.js

@@ -1,5 +1,6 @@
 // This is an example of how to protect content using server rendering
-import { getSession } from "next-auth/react"
+import { getServerSession } from "next-auth/next"
+import { authOptions } from "./api/auth/[...nextauth]"
 import Layout from "../components/layout"
 import AccessDenied from "../components/access-denied"
 
@@ -25,7 +26,7 @@ export default function Page({ content, session }) {
 }
 
 export async function getServerSideProps(context) {
-  const session = await getSession(context)
+  const session = await getServerSession(context, authOptions)
   let content = null
 
   if (session) {

app/pages/styles.css

@@ -4,7 +4,7 @@ body {
   max-width: 680px;
   margin: 0 auto;
   background: #fff;
-  color: #333;
+  color: var(--color-text);
 }
 
 li,

app/tsconfig.json

@@ -16,6 +16,7 @@
     "moduleResolution": "node",
     "resolveJsonModule": true,
     "isolatedModules": true,
+    "incremental": true,
     "jsx": "preserve",
     "baseUrl": ".",
     "paths": {

config/babel.config.js

@@ -31,14 +31,19 @@ module.exports = (api) => {
     comments: false,
     overrides: [
       {
-        test: ["../src/react/index.tsx"],
+        test: [
+          "../src/react/index.tsx",
+          "../src/lib/logger.ts",
+          "../src/core/errors.ts",
+          "../src/client/**",
+        ],
         presets: [
           ["@babel/preset-env", { targets: { ie: 11 } }],
           ["@babel/preset-react", { runtime: "automatic" }],
         ],
       },
       {
-        test: ["../src/server/pages/*.tsx"],
+        test: ["../src/core/pages/*.tsx"],
         presets: ["preact"],
         plugins: [
           [

config/jest.config.js

@@ -12,4 +12,8 @@ module.exports = {
   testMatch: ["**/*.test.js"],
   coverageDirectory: "../coverage",
   testEnvironment: "jsdom",
+  watchPlugins: [
+    "jest-watch-typeahead/filename",
+    "jest-watch-typeahead/testname",
+  ],
 }

package.json

@@ -5,6 +5,11 @@
   "homepage": "https://next-auth.js.org",
   "repository": "https://github.com/nextauthjs/next-auth.git",
   "author": "Iain Collins <me@iaincollins.com>",
+  "contributors": [
+    "Balázs Orbán <info@balazsorban.com>",
+    "Nico Domino <yo@ndo.dev>",
+    "Lluis Agusti <hi@llu.lu>"
+  ],
   "main": "index.js",
   "module": "index.js",
   "types": "index.d.ts",
@@ -21,22 +26,18 @@
     "nextauth"
   ],
   "exports": {
-    ".": {
-      "import": "./index.js"
-    },
-    "./jwt": {
-      "import": "./jwt/index.js"
-    },
-    "./react": {
-      "import": "./react/index.js"
-    },
-    "./providers/*": {
-      "import": "./providers/*.js"
-    }
+    ".": "./index.js",
+    "./jwt": "./jwt/index.js",
+    "./react": "./react/index.js",
+    "./core": "./core/index.js",
+    "./next": "./next/index.js",
+    "./middleware": "./middleware.js",
+    "./client/_utils": "./client/_utils.js",
+    "./providers/*": "./providers/*.js"
   },
   "scripts": {
     "build": "npm run build:js && npm run build:css",
-    "clean": "rm -rf client css lib providers server jwt react index.d.ts index.js adapters.d.ts",
+    "clean": "rm -rf client css lib providers core jwt react next index.d.ts index.js adapters.d.ts middleware.d.ts middleware.js",
     "build:js": "npm run clean && npm run generate-providers && tsc && babel --config-file ./config/babel.config.js src --out-dir . --extensions \".tsx,.ts,.js,.jsx\"",
     "build:css": "postcss --config config/postcss.config.js src/**/*.css --base src --dir . && node config/wrap-css.js",
     "dev:setup": "npm i && npm run generate-providers && npm run build:css && cd app && npm i",
@@ -55,26 +56,32 @@
     "css",
     "jwt",
     "react",
+    "next",
+    "client",
     "providers",
-    "server",
+    "core",
     "index.d.ts",
     "index.js",
-    "adapters.d.ts"
+    "adapters.d.ts",
+    "middleware.d.ts",
+    "middleware.js"
   ],
   "license": "ISC",
   "dependencies": {
-    "@babel/runtime": "^7.14.6",
-    "futoin-hkdf": "^1.3.3",
-    "jose": "^1.27.2",
+    "@babel/runtime": "^7.16.3",
+    "@panva/hkdf": "^1.0.1",
+    "cookie": "^0.4.1",
+    "jose": "^4.3.7",
     "oauth": "^0.9.15",
-    "openid-client": "^4.7.4",
-    "preact": "^10.5.13",
-    "preact-render-to-string": "^5.1.19"
+    "openid-client": "^5.1.0",
+    "preact": "^10.6.3",
+    "preact-render-to-string": "^5.1.19",
+    "uuid": "^8.3.2"
   },
   "peerDependencies": {
-    "nodemailer": "^6.6.2",
-    "react": "^17.0.2",
-    "react-dom": "^17.0.2"
+    "nodemailer": "^6.6.5",
+    "react": "^17.0.2 || ^18.0.0-0",
+    "react-dom": "^17.0.2 || ^18.0.0-0"
   },
   "peerDependenciesMeta": {
     "nodemailer": {
@@ -82,58 +89,60 @@
     }
   },
   "devDependencies": {
-    "@actions/core": "^1.4.0",
-    "@babel/cli": "^7.14.5",
-    "@babel/core": "^7.14.6",
-    "@babel/plugin-proposal-optional-catch-binding": "^7.14.5",
-    "@babel/plugin-transform-runtime": "^7.14.5",
-    "@babel/preset-env": "^7.14.7",
-    "@babel/preset-react": "^7.14.5",
-    "@babel/preset-typescript": "^7.15.0",
-    "@testing-library/jest-dom": "^5.14.1",
-    "@testing-library/react": "^12.0.0",
-    "@testing-library/react-hooks": "^7.0.1",
-    "@testing-library/user-event": "^13.1.9",
+    "@actions/core": "^1.6.0",
+    "@babel/cli": "^7.16.0",
+    "@babel/core": "^7.16.0",
+    "@babel/plugin-proposal-optional-catch-binding": "^7.16.0",
+    "@babel/plugin-transform-runtime": "^7.16.4",
+    "@babel/preset-env": "^7.16.4",
+    "@babel/preset-react": "^7.16.0",
+    "@babel/preset-typescript": "^7.16.0",
+    "@testing-library/jest-dom": "^5.16.1",
+    "@testing-library/react": "^12.1.2",
+    "@testing-library/react-hooks": "^7.0.2",
+    "@testing-library/user-event": "^13.5.0",
+    "@types/node": "^16.11.12",
     "@types/nodemailer": "^6.4.4",
     "@types/oauth": "^0.9.1",
-    "@types/react": "^17.0.19",
-    "@types/react-dom": "^17.0.9",
-    "@typescript-eslint/eslint-plugin": "^4.29.2",
-    "@typescript-eslint/parser": "^4.29.2",
-    "autoprefixer": "^10.2.6",
-    "babel-jest": "^27.0.5",
+    "@types/react": "^17.0.37",
+    "@types/react-dom": "^17.0.11",
+    "@typescript-eslint/parser": "^4.33.0",
+    "autoprefixer": "^10.4.0",
+    "babel-jest": "^27.4.2",
     "babel-plugin-jsx-pragmatic": "^1.0.2",
     "babel-preset-preact": "^2.0.0",
-    "conventional-changelog-conventionalcommits": "4.6.0",
-    "cssnano": "^5.0.6",
-    "eslint": "^7.29.0",
+    "conventional-changelog-conventionalcommits": "4.6.1",
+    "cssnano": "^5.0.12",
+    "eslint": "^7.32.0",
     "eslint-config-prettier": "^8.3.0",
-    "eslint-config-standard-with-typescript": "^20.0.0",
-    "eslint-plugin-import": "^2.23.4",
-    "eslint-plugin-jest": "^24.3.6",
+    "eslint-config-standard-with-typescript": "^21.0.1",
+    "eslint-plugin-jest": "^25.3.0",
     "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-promise": "^5.1.0",
     "fs-extra": "^10.0.0",
-    "husky": "^6.0.0",
-    "jest": "^27.0.5",
-    "msw": "^0.30.0",
-    "next": "v11.1.3-canary.0",
-    "postcss-cli": "^8.3.1",
-    "postcss-nested": "^5.0.5",
-    "prettier": "^2.3.1",
-    "pretty-quick": "^3.1.1",
+    "husky": "^7.0.4",
+    "jest": "^27.4.3",
+    "jest-watch-typeahead": "^1.0.0",
+    "msw": "^0.36.3",
+    "next": "12.0.9",
+    "postcss-cli": "^9.0.2",
+    "postcss-nested": "^5.0.6",
+    "prettier": "2.4.1",
+    "pretty-quick": "^3.1.2",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
-    "typescript": "^4.3.5",
+    "typescript": "^4.5.2",
     "whatwg-fetch": "^3.6.2"
   },
+  "engines": {
+    "node": "^12.19.0 || ^14.15.0 || ^16.13.0"
+  },
   "prettier": {
     "semi": false
   },
   "eslintConfig": {
     "parser": "@typescript-eslint/parser",
     "parserOptions": {
-      "project": "./tsconfig.json"
+      "project": "./tsconfig.eslint.json"
     },
     "extends": [
       "standard-with-typescript",
@@ -145,7 +154,7 @@
       "types",
       ".next",
       "dist",
-      "/server",
+      "/core",
       "/react.js"
     ],
     "globals": {
@@ -177,6 +186,11 @@
       }
     ]
   },
+  "eslintIgnore": [
+    "./*.d.ts",
+    "**/tests",
+    "**/__tests__"
+  ],
   "release": {
     "branches": [
       "+([0-9])?(.{+([0-9]),x}).x",
@@ -207,6 +221,10 @@
     {
       "type": "github",
       "url": "https://github.com/sponsors/balazsorban44"
+    },
+    {
+      "type": "opencollective",
+      "url": "https://opencollective.com/nextauth"
     }
   ]
 }

src/client/__tests__/helpers/mocks.js

@@ -65,26 +65,28 @@ export const mockSignOutResponse = {
 }
 
 export const server = setupServer(
-  rest.post("/api/auth/signout", (req, res, ctx) =>
+  rest.post("http://localhost/api/auth/signout", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockSignOutResponse))
   ),
-  rest.get("/api/auth/session", (req, res, ctx) =>
+  rest.get("http://localhost/api/auth/session", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockSession))
   ),
-  rest.get("/api/auth/csrf", (req, res, ctx) =>
+  rest.get("http://localhost/api/auth/csrf", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockCSRFToken))
   ),
-  rest.get("/api/auth/providers", (req, res, ctx) =>
+  rest.get("http://localhost/api/auth/providers", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockProviders))
   ),
-  rest.post("/api/auth/signin/github", (req, res, ctx) =>
+  rest.post("http://localhost/api/auth/signin/github", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockGithubResponse))
   ),
-  rest.post("/api/auth/callback/credentials", (req, res, ctx) =>
+  rest.post("http://localhost/api/auth/callback/credentials", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockCredentialsResponse))
   ),
-  rest.post("/api/auth/signin/email", (req, res, ctx) =>
+  rest.post("http://localhost/api/auth/signin/email", (req, res, ctx) =>
     res(ctx.status(200), ctx.json(mockEmailResponse))
   ),
-  rest.post("/api/auth/_log", (req, res, ctx) => res(ctx.status(200)))
+  rest.post("http://localhost/api/auth/_log", (req, res, ctx) =>
+    res(ctx.status(200))
+  )
 )

src/client/__tests__/sign-in.test.js

@@ -27,12 +27,22 @@ jest.mock("../../lib/logger", () => ({
 
 beforeAll(() => {
   server.listen()
+
+  let _href = window.location.href
+  // Allows to mutate `window.location`...
   delete window.location
+
   window.location = {
-    ...location,
-    replace: jest.fn(),
     reload: jest.fn(),
   }
+  Object.defineProperty(window.location, "href", {
+    get: () => _href,
+    // whatwg-fetch or whatwg-url does not seem to work with relative URLs
+    set: (href) => {
+      _href = href.startsWith("/") ? `http://localhost${href}` : href
+      return _href
+    },
+  })
 })
 
 beforeEach(() => {
@@ -59,9 +69,10 @@ test.each`
     userEvent.click(screen.getByRole("button"))
 
     await waitFor(() => {
-      expect(window.location.replace).toHaveBeenCalledTimes(1)
-      expect(window.location.replace).toHaveBeenCalledWith(
-        `/api/auth/signin?callbackUrl=${encodeURIComponent(callbackUrl)}`
+      expect(window.location.href).toBe(
+        `http://localhost/api/auth/signin?${new URLSearchParams({
+          callbackUrl,
+        })}`
       )
     })
   }
@@ -76,14 +87,14 @@ test.each`
   async ({ provider }) => {
     render(<SignInFlow providerId={provider} />)
 
+    const callbackUrl = window.location.href
     userEvent.click(screen.getByRole("button"))
 
     await waitFor(() => {
-      expect(window.location.replace).toHaveBeenCalledTimes(1)
-      expect(window.location.replace).toHaveBeenCalledWith(
-        `/api/auth/signin?callbackUrl=${encodeURIComponent(
-          window.location.href
-        )}`
+      expect(window.location.href).toBe(
+        `http://localhost/api/auth/signin?${new URLSearchParams({
+          callbackUrl,
+        })}`
       )
     })
   }
@@ -101,8 +112,7 @@ test.each`
     userEvent.click(screen.getByRole("button"))
 
     await waitFor(() => {
-      expect(window.location.replace).toHaveBeenCalledTimes(1)
-      expect(window.location.replace).toHaveBeenCalledWith(mockUrl)
+      expect(window.location.href).toBe(mockUrl)
     })
   }
 )
@@ -119,8 +129,7 @@ test("redirection can't be stopped using an oauth provider", async () => {
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).toHaveBeenCalledTimes(1)
-    expect(window.location.replace).toHaveBeenCalledWith(mockGithubResponse.url)
+    expect(window.location.href).toBe(mockGithubResponse.url)
   })
 })
 
@@ -136,9 +145,7 @@ test("redirection can be stopped using the 'credentials' provider", async () =>
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).not.toHaveBeenCalledWith(
-      mockCredentialsResponse.url
-    )
+    expect(window.location.href).not.toBe(mockCredentialsResponse.url)
 
     expect(screen.getByTestId("signin-result").textContent).not.toBe(
       "no response"
@@ -165,9 +172,7 @@ test("redirection can be stopped using the 'email' provider", async () => {
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).not.toHaveBeenCalledWith(
-      mockEmailResponse.url
-    )
+    expect(window.location.href).not.toBe(mockEmailResponse.url)
 
     expect(screen.getByTestId("signin-result").textContent).not.toBe(
       "no response"
@@ -190,7 +195,7 @@ test("if callback URL contains a hash we force a window reload when re-directing
   const mockUrlWithHash = "https://path/to/email/url#foo-bar-baz"
 
   server.use(
-    rest.post("/api/auth/signin/email", (req, res, ctx) => {
+    rest.post("http://localhost/api/auth/signin/email", (req, res, ctx) => {
       return res(
         ctx.status(200),
         ctx.json({
@@ -206,8 +211,7 @@ test("if callback URL contains a hash we force a window reload when re-directing
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).toHaveBeenCalledTimes(1)
-    expect(window.location.replace).toHaveBeenCalledWith(mockUrlWithHash)
+    expect(window.location.href).toBe(mockUrlWithHash)
     // the browser will not refresh the page if the redirect URL contains a hash, hence we force it on the client, see #1289
     expect(window.location.reload).toHaveBeenCalledTimes(1)
   })
@@ -218,7 +222,7 @@ test("params are propagated to the signin URL when supplied", async () => {
   const authParams = "foo=bar&bar=foo"
 
   server.use(
-    rest.post("/api/auth/signin/github", (req, res, ctx) => {
+    rest.post("http://localhost/api/auth/signin/github", (req, res, ctx) => {
       matchedParams = req.url.search
       return res(ctx.status(200), ctx.json(mockGithubResponse))
     })
@@ -237,7 +241,7 @@ test("when it fails to fetch the providers, it redirected back to signin page",
   const errorMsg = "Error when retrieving providers"
 
   server.use(
-    rest.get("/api/auth/providers", (req, res, ctx) =>
+    rest.get("http://localhost/api/auth/providers", (req, res, ctx) =>
       res(ctx.status(500), ctx.json(errorMsg))
     )
   )
@@ -247,7 +251,7 @@ test("when it fails to fetch the providers, it redirected back to signin page",
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).toHaveBeenCalledWith(`/api/auth/error`)
+    expect(window.location.href).toBe(`http://localhost/api/auth/error`)
 
     expect(logger.error).toHaveBeenCalledTimes(1)
     expect(logger.error).toBeCalledWith("CLIENT_FETCH_ERROR", {
@@ -268,10 +272,7 @@ function SignInFlow({
   async function handleSignIn() {
     const result = await signIn(
       providerId,
-      {
-        callbackUrl,
-        redirect,
-      },
+      { callbackUrl, redirect },
       authorizationParams
     )
 

src/client/__tests__/sign-out.test.js

@@ -10,11 +10,11 @@ const { location } = window
 
 beforeAll(() => {
   server.listen()
+  // Allows to mutate `window.location`...
   delete window.location
   window.location = {
-    ...location,
-    replace: jest.fn(),
     reload: jest.fn(),
+    href: location.href,
   }
 })
 
@@ -37,7 +37,7 @@ const callbackUrl = "https://redirects/to"
 
 test("by default it redirects to the current URL if the server did not provide one", async () => {
   server.use(
-    rest.post("/api/auth/signout", (req, res, ctx) =>
+    rest.post("http://localhost/api/auth/signout", (req, res, ctx) =>
       res(ctx.status(200), ctx.json({ ...mockSignOutResponse, url: undefined }))
     )
   )
@@ -47,8 +47,7 @@ test("by default it redirects to the current URL if the server did not provide o
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).toHaveBeenCalledTimes(1)
-    expect(window.location.replace).toHaveBeenCalledWith(window.location.href)
+    expect(window.location.href).toBe(window.location.href)
   })
 })
 
@@ -58,10 +57,7 @@ test("it redirects to the URL allowed by the server", async () => {
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.replace).toHaveBeenCalledTimes(1)
-    expect(window.location.replace).toHaveBeenCalledWith(
-      mockSignOutResponse.url
-    )
+    expect(window.location.href).toBe(mockSignOutResponse.url)
   })
 })
 
@@ -69,7 +65,7 @@ test("if url contains a hash during redirection a page reload happens", async ()
   const mockUrlWithHash = "https://path/to/email/url#foo-bar-baz"
 
   server.use(
-    rest.post("/api/auth/signout", (req, res, ctx) => {
+    rest.post("http://localhost/api/auth/signout", (req, res, ctx) => {
       return res(
         ctx.status(200),
         ctx.json({
@@ -85,8 +81,7 @@ test("if url contains a hash during redirection a page reload happens", async ()
   userEvent.click(screen.getByRole("button"))
 
   await waitFor(() => {
-    expect(window.location.reload).toHaveBeenCalledTimes(1)
-    expect(window.location.replace).toHaveBeenCalledWith(mockUrlWithHash)
+    expect(window.location.href).toBe(mockUrlWithHash)
   })
 })
 

src/client/__tests__/use-session-hook.test.js

@@ -5,24 +5,32 @@ import { SessionProvider, useSession, signOut } from "../../react"
 import { server, mockSession } from "./helpers/mocks"
 
 const origConsoleError = console.error
-const origLocation = window.location
-const locationReplace = jest.fn()
+const { location } = window
 
+let _href = window.location.href
 beforeAll(() => {
   // Prevent noise on the terminal... `next-auth` will log to `console.error`
   // every time a request fails, which makes the tests output very noisy...
   console.error = jest.fn()
 
-  // Allows to spy on `window.location.replace`...
+  // Allows to mutate `window.location`...
   delete window.location
-  window.location = { ...origLocation, replace: locationReplace }
+  window.location = {}
+  Object.defineProperty(window.location, "href", {
+    get: () => _href,
+    // whatwg-fetch or whatwg-url does not seem to work with relative URLs
+    set: (href) => {
+      _href = href.startsWith("/") ? `http://localhost${href}` : href
+      return _href
+    },
+  })
 
   server.listen()
 })
 
 afterEach(() => {
   server.resetHandlers()
-  locationReplace.mockClear()
+  _href = "http://localhost/"
 
   // clear the internal session cache...
   signOut({ redirect: false })
@@ -30,7 +38,7 @@ afterEach(() => {
 
 afterAll(() => {
   console.error = origConsoleError
-  window.location = origLocation
+  window.location = location
   server.close()
 })
 
@@ -67,7 +75,7 @@ test("when session is fetched, `data` will contain the session data and `status`
 
 test("when it fails to fetch the session, `data` will be null and `status` will be 'unauthenticated'", async () => {
   server.use(
-    rest.get(`/api/auth/session`, (req, res, ctx) =>
+    rest.get(`http://localhost/api/auth/session`, (_, res, ctx) =>
       res(ctx.status(401), ctx.json({}))
     )
   )
@@ -84,11 +92,12 @@ test("when it fails to fetch the session, `data` will be null and `status` will
 
 test("it'll redirect to sign-in page if the session is required and the user is not authenticated", async () => {
   server.use(
-    rest.get(`/api/auth/session`, (req, res, ctx) =>
+    rest.get(`http://localhost/api/auth/session`, (req, res, ctx) =>
       res(ctx.status(401), ctx.json({}))
     )
   )
 
+  const callbackUrl = window.location.href
   const { result } = renderHook(() => useSession({ required: true }), {
     wrapper: SessionProvider,
   })
@@ -98,25 +107,17 @@ test("it'll redirect to sign-in page if the session is required and the user is
     expect(result.current.status).toBe("loading")
   })
 
-  expect(locationReplace).toHaveBeenCalledTimes(1)
-
-  expect(locationReplace).toHaveBeenCalledWith(
-    expect.stringContaining("/api/auth/signin")
-  )
-
-  expect(locationReplace).toHaveBeenCalledWith(
-    expect.stringContaining(
-      new URLSearchParams({
-        error: "SessionRequired",
-        callbackUrl: window.location.href,
-      }).toString()
-    )
+  expect(window.location.href).toBe(
+    `http://localhost/api/auth/signin?${new URLSearchParams({
+      error: "SessionRequired",
+      callbackUrl,
+    })}`
   )
 })
 
 test("will call custom redirect logic if supplied when the user could not authenticate", async () => {
   server.use(
-    rest.get(`/api/auth/session`, (req, res, ctx) =>
+    rest.get(`http://localhost/api/auth/session`, (_, res, ctx) =>
       res(ctx.status(401), ctx.json({}))
     )
   )
@@ -135,8 +136,5 @@ test("will call custom redirect logic if supplied when the user could not authen
     expect(result.current.status).toBe("loading")
   })
 
-  // it shouldn't have tried to re-direct to sign-in page (default behavior)
-  expect(locationReplace).not.toHaveBeenCalled()
-
   expect(customRedirect).toHaveBeenCalledTimes(1)
 })

src/client/_utils.ts

@@ -45,7 +45,7 @@ export async function fetchData<T = any>(
     return Object.keys(data).length > 0 ? data : null // Return null if data empty
   } catch (error) {
     logger.error("CLIENT_FETCH_ERROR", {
-      error,
+      error: error as Error,
       path,
       ...(req ? { header: req.headers } : {}),
     })
@@ -84,9 +84,9 @@ export function BroadcastChannel(name = "nextauth.message") {
   return {
     /** Get notified by other tabs/windows. */
     receive(onReceive: (message: BroadcastMessage) => void) {
-      const handler = (event) => {
+      const handler = (event: StorageEvent) => {
         if (event.key !== name) return
-        const message: BroadcastMessage = JSON.parse(event.newValue)
+        const message: BroadcastMessage = JSON.parse(event.newValue ?? "{}")
         if (message?.event !== "session" || !message?.data) return
 
         onReceive(message)
@@ -95,7 +95,7 @@ export function BroadcastChannel(name = "nextauth.message") {
       return () => window.removeEventListener("storage", handler)
     },
     /** Notify other tabs/windows. */
-    post(message) {
+    post(message: Record<string, unknown>) {
       if (typeof window === "undefined") return
       localStorage.setItem(
         name,

src/core/errors.ts

@@ -1,15 +1,17 @@
-import { EventCallbacks, LoggerInstance } from ".."
-import { Adapter } from "../adapters"
+import type { EventCallbacks, LoggerInstance } from ".."
+import type { Adapter } from "../adapters"
 
 /**
  * Same as the default `Error`, but it is JSON serializable.
  * @source https://iaincollins.medium.com/error-handling-in-javascript-a6172ccdf9af
  */
 export class UnknownError extends Error {
-  constructor(error) {
+  code: string
+  constructor(error: Error | string) {
     // Support passing error or string
-    super(error?.message ?? error)
+    super((error as Error)?.message ?? error)
     this.name = "UnknownError"
+    this.code = (error as any).code
     if (error instanceof Error) {
       this.stack = error.stack
     }
@@ -36,6 +38,31 @@ export class AccountNotLinkedError extends UnknownError {
   name = "AccountNotLinkedError"
 }
 
+export class MissingAPIRoute extends UnknownError {
+  name = "MissingAPIRouteError"
+  code = "MISSING_NEXTAUTH_API_ROUTE_ERROR"
+}
+
+export class MissingSecret extends UnknownError {
+  name = "MissingSecretError"
+  code = "NO_SECRET"
+}
+
+export class MissingAuthorize extends UnknownError {
+  name = "MissingAuthorizeError"
+  code = "CALLBACK_CREDENTIALS_HANDLER_ERROR"
+}
+
+export class MissingAdapter extends UnknownError {
+  name = "MissingAdapterError"
+  code = "EMAIL_REQUIRES_ADAPTER_ERROR"
+}
+
+export class UnsupportedStrategy extends UnknownError {
+  name = "UnsupportedStrategyError"
+  code = "CALLBACK_CREDENTIALS_JWT_ERROR"
+}
+
 type Method = (...args: any[]) => Promise<any>
 
 export function upperSnake(s: string) {
@@ -56,10 +83,10 @@ export function eventsErrorHandler(
   return Object.keys(methods).reduce<any>((acc, name) => {
     acc[name] = async (...args: any[]) => {
       try {
-        const method: Method = methods[name]
+        const method: Method = methods[name as keyof Method]
         return await method(...args)
       } catch (e) {
-        logger.error(`${upperSnake(name)}_EVENT_ERROR`, e)
+        logger.error(`${upperSnake(name)}_EVENT_ERROR`, e as Error)
       }
     }
     return acc
@@ -77,11 +104,11 @@ export function adapterErrorHandler(
     acc[name] = async (...args: any[]) => {
       try {
         logger.debug(`adapter_${name}`, { args })
-        const method: Method = adapter[name as any]
+        const method: Method = adapter[name as keyof Method]
         return await method(...args)
       } catch (error) {
-        logger.error(`adapter_error_${name}`, error)
-        const e = new UnknownError(error)
+        logger.error(`adapter_error_${name}`, error as Error)
+        const e = new UnknownError(error as Error)
         e.name = `${capitalize(name)}Error`
         throw e
       }

src/core/index.ts

@@ -0,0 +1,236 @@
+import logger, { setLogger } from "../lib/logger"
+import * as routes from "./routes"
+import renderPage from "./pages"
+import { init } from "./init"
+import { assertConfig } from "./lib/assert"
+import { SessionStore } from "./lib/cookie"
+
+import type { NextAuthOptions } from "./types"
+import type { NextAuthAction } from "../lib/types"
+import type { Cookie } from "./lib/cookie"
+import type { ErrorType } from "./pages/error"
+
+export interface IncomingRequest {
+  /** @default "http://localhost:3000" */
+  host?: string
+  method?: string
+  cookies?: Record<string, string>
+  headers?: Record<string, any>
+  query?: Record<string, any>
+  body?: Record<string, any>
+  action: NextAuthAction
+  providerId?: string
+  error?: string
+}
+
+export interface NextAuthHeader {
+  key: string
+  value: string
+}
+
+export interface OutgoingResponse<
+  Body extends string | Record<string, any> | any[] = any
+> {
+  status?: number
+  headers?: NextAuthHeader[]
+  body?: Body
+  redirect?: string
+  cookies?: Cookie[]
+}
+
+export interface NextAuthHandlerParams {
+  req: IncomingRequest
+  options: NextAuthOptions
+}
+
+export async function NextAuthHandler<
+  Body extends string | Record<string, any> | any[]
+>(params: NextAuthHandlerParams): Promise<OutgoingResponse<Body>> {
+  const { options: userOptions, req } = params
+
+  setLogger(userOptions.logger, userOptions.debug)
+
+  const assertionResult = assertConfig(params)
+
+  if (typeof assertionResult === "string") {
+    logger.warn(assertionResult)
+  } else if (assertionResult instanceof Error) {
+    // Bail out early if there's an error in the user config
+    const { pages, theme } = userOptions
+    logger.error(assertionResult.code, assertionResult)
+    if (pages?.error) {
+      return {
+        redirect: `${pages.error}?error=Configuration`,
+      }
+    }
+    const render = renderPage({ theme })
+    return render.error({ error: "configuration" })
+  }
+
+  const { action, providerId, error, method = "GET" } = req
+
+  const { options, cookies } = await init({
+    userOptions,
+    action,
+    providerId,
+    host: req.host,
+    callbackUrl: req.body?.callbackUrl ?? req.query?.callbackUrl,
+    csrfToken: req.body?.csrfToken,
+    cookies: req.cookies,
+    isPost: method === "POST",
+  })
+
+  const sessionStore = new SessionStore(
+    options.cookies.sessionToken,
+    req,
+    options.logger
+  )
+
+  if (method === "GET") {
+    const render = renderPage({ ...options, query: req.query, cookies })
+    const { pages } = options
+    switch (action) {
+      case "providers":
+        return (await routes.providers(options.providers)) as any
+      case "session": {
+        const session = await routes.session({ options, sessionStore })
+        if (session.cookies) cookies.push(...session.cookies)
+        return { ...session, cookies } as any
+      }
+      case "csrf":
+        return {
+          headers: [{ key: "Content-Type", value: "application/json" }],
+          body: { csrfToken: options.csrfToken } as any,
+          cookies,
+        }
+      case "signin":
+        if (pages.signIn) {
+          let signinUrl = `${pages.signIn}${
+            pages.signIn.includes("?") ? "&" : "?"
+          }callbackUrl=${options.callbackUrl}`
+          if (error) signinUrl = `${signinUrl}&error=${error}`
+          return { redirect: signinUrl, cookies }
+        }
+
+        return render.signin()
+      case "signout":
+        if (pages.signOut) return { redirect: pages.signOut, cookies }
+
+        return render.signout()
+      case "callback":
+        if (options.provider) {
+          const callback = await routes.callback({
+            body: req.body,
+            query: req.query,
+            headers: req.headers,
+            cookies: req.cookies,
+            method,
+            options,
+            sessionStore,
+          })
+          if (callback.cookies) cookies.push(...callback.cookies)
+          return { ...callback, cookies }
+        }
+        break
+      case "verify-request":
+        if (pages.verifyRequest) {
+          return { redirect: pages.verifyRequest, cookies }
+        }
+        return render.verifyRequest()
+      case "error":
+        // These error messages are displayed in line on the sign in page
+        if (
+          [
+            "Signin",
+            "OAuthSignin",
+            "OAuthCallback",
+            "OAuthCreateAccount",
+            "EmailCreateAccount",
+            "Callback",
+            "OAuthAccountNotLinked",
+            "EmailSignin",
+            "CredentialsSignin",
+            "SessionRequired",
+          ].includes(error as string)
+        ) {
+          return { redirect: `${options.url}/signin?error=${error}`, cookies }
+        }
+
+        if (pages.error) {
+          return {
+            redirect: `${pages.error}${
+              pages.error.includes("?") ? "&" : "?"
+            }error=${error}`,
+            cookies,
+          }
+        }
+
+        return render.error({ error: error as ErrorType })
+      default:
+    }
+  } else if (method === "POST") {
+    switch (action) {
+      case "signin":
+        // Verified CSRF Token required for all sign in routes
+        if (options.csrfTokenVerified && options.provider) {
+          const signin = await routes.signin({
+            query: req.query,
+            body: req.body,
+            options,
+          })
+          if (signin.cookies) cookies.push(...signin.cookies)
+          return { ...signin, cookies }
+        }
+
+        return { redirect: `${options.url}/signin?csrf=true`, cookies }
+      case "signout":
+        // Verified CSRF Token required for signout
+        if (options.csrfTokenVerified) {
+          const signout = await routes.signout({ options, sessionStore })
+          if (signout.cookies) cookies.push(...signout.cookies)
+          return { ...signout, cookies }
+        }
+        return { redirect: `${options.url}/signout?csrf=true`, cookies }
+      case "callback":
+        if (options.provider) {
+          // Verified CSRF Token required for credentials providers only
+          if (
+            options.provider.type === "credentials" &&
+            !options.csrfTokenVerified
+          ) {
+            return { redirect: `${options.url}/signin?csrf=true`, cookies }
+          }
+
+          const callback = await routes.callback({
+            body: req.body,
+            query: req.query,
+            headers: req.headers,
+            cookies: req.cookies,
+            method,
+            options,
+            sessionStore,
+          })
+          if (callback.cookies) cookies.push(...callback.cookies)
+          return { ...callback, cookies }
+        }
+        break
+      case "_log":
+        if (userOptions.logger) {
+          try {
+            const { code, level, ...metadata } = req.body ?? {}
+            logger[level](code, metadata)
+          } catch (error) {
+            // If logging itself failed...
+            logger.error("LOGGER_ERROR", error as Error)
+          }
+        }
+        return {}
+      default:
+    }
+  }
+
+  return {
+    status: 400,
+    body: `Error: Action ${action} with HTTP ${method} is not supported by NextAuth.js` as any,
+  }
+}

src/core/init.ts

@@ -0,0 +1,147 @@
+import { NextAuthOptions } from ".."
+import logger from "../lib/logger"
+import parseUrl from "../lib/parse-url"
+import { InternalOptions } from "../lib/types"
+import { adapterErrorHandler, eventsErrorHandler } from "./errors"
+import parseProviders from "./lib/providers"
+import createSecret from "./lib/utils"
+import * as cookie from "./lib/cookie"
+import * as jwt from "../jwt"
+import { defaultCallbacks } from "./lib/default-callbacks"
+import { createCSRFToken } from "./lib/csrf-token"
+import { createCallbackUrl } from "./lib/callback-url"
+import { IncomingRequest } from "."
+
+interface InitParams {
+  host?: string
+  userOptions: NextAuthOptions
+  providerId?: string
+  action: InternalOptions["action"]
+  /** Callback URL value extracted from the incoming request. */
+  callbackUrl?: string
+  /** CSRF token value extracted from the incoming request. From body if POST, from query if GET */
+  csrfToken?: string
+  /** Is the incoming request a POST request? */
+  isPost: boolean
+  cookies: IncomingRequest["cookies"]
+}
+
+/** Initialize all internal options and cookies. */
+export async function init({
+  userOptions,
+  providerId,
+  action,
+  host,
+  cookies: reqCookies,
+  callbackUrl: reqCallbackUrl,
+  csrfToken: reqCsrfToken,
+  isPost,
+}: InitParams): Promise<{
+  options: InternalOptions
+  cookies: cookie.Cookie[]
+}> {
+  const url = parseUrl(host)
+
+  const secret = createSecret({ userOptions, url })
+
+  const { providers, provider } = parseProviders({
+    providers: userOptions.providers,
+    url,
+    providerId,
+  })
+
+  const maxAge = 30 * 24 * 60 * 60 // Sessions expire after 30 days of being idle by default
+
+  // User provided options are overriden by other options,
+  // except for the options with special handling above
+  const options: InternalOptions = {
+    debug: false,
+    pages: {},
+    theme: {
+      colorScheme: "auto",
+      logo: "",
+      brandColor: "",
+    },
+    // Custom options override defaults
+    ...userOptions,
+    // These computed settings can have values in userOptions but we override them
+    // and are request-specific.
+    url,
+    action,
+    provider,
+    cookies: {
+      ...cookie.defaultCookies(
+        userOptions.useSecureCookies ?? url.base.startsWith("https://")
+      ),
+      // Allow user cookie options to override any cookie settings above
+      ...userOptions.cookies,
+    },
+    secret,
+    providers,
+    // Session options
+    session: {
+      // If no adapter specified, force use of JSON Web Tokens (stateless)
+      strategy: userOptions.adapter ? "database" : "jwt",
+      maxAge,
+      updateAge: 24 * 60 * 60,
+      ...userOptions.session,
+    },
+    // JWT options
+    jwt: {
+      secret, // Use application secret if no keys specified
+      maxAge, // same as session maxAge,
+      encode: jwt.encode,
+      decode: jwt.decode,
+      ...userOptions.jwt,
+    },
+    // Event messages
+    events: eventsErrorHandler(userOptions.events ?? {}, logger),
+    adapter: adapterErrorHandler(userOptions.adapter, logger),
+    // Callback functions
+    callbacks: { ...defaultCallbacks, ...userOptions.callbacks },
+    logger,
+    callbackUrl: url.origin,
+  }
+
+  // Init cookies
+
+  const cookies: cookie.Cookie[] = []
+
+  const {
+    csrfToken,
+    cookie: csrfCookie,
+    csrfTokenVerified,
+  } = createCSRFToken({
+    options,
+    cookieValue: reqCookies?.[options.cookies.csrfToken.name],
+    isPost,
+    bodyValue: reqCsrfToken,
+  })
+
+  options.csrfToken = csrfToken
+  options.csrfTokenVerified = csrfTokenVerified
+
+  if (csrfCookie) {
+    cookies.push({
+      name: options.cookies.csrfToken.name,
+      value: csrfCookie,
+      options: options.cookies.csrfToken.options,
+    })
+  }
+
+  const { callbackUrl, callbackUrlCookie } = await createCallbackUrl({
+    options,
+    cookieValue: reqCookies?.[options.cookies.callbackUrl.name],
+    paramValue: reqCallbackUrl,
+  })
+  options.callbackUrl = callbackUrl
+  if (callbackUrlCookie) {
+    cookies.push({
+      name: options.cookies.callbackUrl.name,
+      value: callbackUrlCookie,
+      options: options.cookies.callbackUrl.options,
+    })
+  }
+
+  return { options, cookies }
+}

src/core/lib/assert.ts

@@ -0,0 +1,87 @@
+import {
+  MissingAdapter,
+  MissingAPIRoute,
+  MissingAuthorize,
+  MissingSecret,
+  UnsupportedStrategy,
+} from "../errors"
+
+import type { NextAuthHandlerParams } from ".."
+import type { WarningCode } from "../../lib/logger"
+
+type ConfigError =
+  | MissingAPIRoute
+  | MissingSecret
+  | UnsupportedStrategy
+  | MissingAuthorize
+  | MissingAdapter
+
+let twitterWarned = false
+
+/**
+ * Verify that the user configured `next-auth` correctly.
+ * Good place to mention deprecations as well.
+ *
+ * REVIEW: Make some of these and corresponding docs less Next.js specific?
+ */
+export function assertConfig(
+  params: NextAuthHandlerParams
+): ConfigError | WarningCode | undefined {
+  const { options, req } = params
+
+  // req.query isn't defined when asserting `getServerSession` for example
+  if (!req.query?.nextauth && !req.action) {
+    return new MissingAPIRoute(
+      "Cannot find [...nextauth].{js,ts} in `/pages/api/auth`. Make sure the filename is written correctly."
+    )
+  }
+
+  if (!options.secret) {
+    if (process.env.NODE_ENV === "production") {
+      return new MissingSecret("Please define a `secret` in production.")
+    } else {
+      return "NO_SECRET"
+    }
+  }
+
+  if (!req.host) return "NEXTAUTH_URL"
+
+  let hasCredentials, hasEmail
+  let hasTwitterProvider
+
+  for (const provider of options.providers) {
+    if (provider.type === "credentials") hasCredentials = true
+    else if (provider.type === "email") hasEmail = true
+    else if (provider.id === "twitter") hasTwitterProvider = true
+  }
+
+  if (hasCredentials) {
+    const dbStrategy = options.session?.strategy === "database"
+    const onlyCredentials = !options.providers.some(
+      (p) => p.type !== "credentials"
+    )
+    if (dbStrategy && onlyCredentials) {
+      return new UnsupportedStrategy(
+        "Signin in with credentials only supported if JWT strategy is enabled"
+      )
+    }
+
+    const credentialsNoAuthorize = options.providers.some(
+      (p) => p.type === "credentials" && !p.authorize
+    )
+    if (credentialsNoAuthorize) {
+      return new MissingAuthorize(
+        "Must define an authorize() handler to use credentials authentication provider"
+      )
+    }
+  }
+
+  if (hasEmail && !options.adapter) {
+    return new MissingAdapter("E-mail login requires an adapter.")
+  }
+
+  if (!twitterWarned && hasTwitterProvider) {
+    twitterWarned = true
+    return "TWITTER_OAUTH_2_BETA"
+  }
+}

src/core/lib/callback-handler.ts

@@ -19,12 +19,13 @@ import { SessionToken } from "./cookie"
  * done prior to this handler being called to avoid additonal complexity in this
  * handler.
  */
-export default async function callbackHandler(
-  sessionToken: SessionToken,
-  profile: User,
-  account: Account,
+export default async function callbackHandler(params: {
+  sessionToken?: SessionToken
+  profile: User
+  account: Account
   options: InternalOptions
-) {
+}) {
+  const { sessionToken, profile, account, options } = params
   // Input validation
   if (!account?.providerAccountId || !account.type)
     throw new Error("Missing or invalid provider account")
@@ -35,7 +36,7 @@ export default async function callbackHandler(
     adapter,
     jwt,
     events,
-    session: { jwt: useJwtSession },
+    session: { strategy: sessionStrategy },
   } = options
 
   // If no adapter is configured then we don't have a database and cannot
@@ -60,6 +61,8 @@ export default async function callbackHandler(
   let user: AdapterUser | null = null
   let isNewUser = false
 
+  const useJwtSession = sessionStrategy === "jwt"
+
   if (sessionToken) {
     if (useJwtSession) {
       try {

src/core/lib/callback-url.ts

@@ -0,0 +1,42 @@
+import { InternalOptions } from "../../lib/types"
+
+interface CreateCallbackUrlParams {
+  options: InternalOptions
+  /** Try reading value from request body (POST) then from query param (GET) */
+  paramValue?: string
+  cookieValue?: string
+}
+
+/**
+ * Get callback URL based on query param / cookie + validation,
+ * and add it to `req.options.callbackUrl`.
+ */
+export async function createCallbackUrl({
+  options,
+  paramValue,
+  cookieValue,
+}: CreateCallbackUrlParams) {
+  const { url, callbacks } = options
+
+  let callbackUrl = url.origin
+
+  if (paramValue) {
+    // If callbackUrl form field or query parameter is passed try to use it if allowed
+    callbackUrl = await callbacks.redirect({
+      url: paramValue,
+      baseUrl: url.origin,
+    })
+  } else if (cookieValue) {
+    // If no callbackUrl specified, try using the value from the cookie if allowed
+    callbackUrl = await callbacks.redirect({
+      url: cookieValue,
+      baseUrl: url.origin,
+    })
+  }
+
+  return {
+    callbackUrl,
+    // Save callback URL in a cookie so that it can be used for subsequent requests in signin/signout/callback flow
+    callbackUrlCookie: callbackUrl !== cookieValue ? callbackUrl : undefined,
+  }
+}

src/core/lib/cookie.ts

@@ -0,0 +1,212 @@
+import type { IncomingHttpHeaders } from "http"
+import type { CookiesOptions } from "../.."
+import type { CookieOption, LoggerInstance, SessionStrategy } from "../types"
+
+// Uncomment to recalculate the estimated size
+// of an empty session cookie
+// import { serialize } from "cookie"
+// console.log(
+//   "Cookie estimated to be ",
+//   serialize(`__Secure.next-auth.session-token.0`, "", {
+//     expires: new Date(),
+//     httpOnly: true,
+//     maxAge: Number.MAX_SAFE_INTEGER,
+//     path: "/",
+//     sameSite: "strict",
+//     secure: true,
+//     domain: "example.com",
+//   }).length,
+//   " bytes"
+// )
+
+const ALLOWED_COOKIE_SIZE = 4096
+// Based on commented out section above
+const ESTIMATED_EMPTY_COOKIE_SIZE = 163
+const CHUNK_SIZE = ALLOWED_COOKIE_SIZE - ESTIMATED_EMPTY_COOKIE_SIZE
+
+// REVIEW: Is there any way to defer two types of strings?
+
+/** Stringified form of `JWT`. Extract the content with `jwt.decode` */
+export type JWTString = string
+
+export type SetCookieOptions = Partial<CookieOption["options"]> & {
+  expires?: Date | string
+  encode?: (val: unknown) => string
+}
+
+/**
+ * If `options.session.strategy` is set to `jwt`, this is a stringified `JWT`.
+ * In case of `strategy: "database"`, this is the `sessionToken` of the session in the database.
+ */
+export type SessionToken<T extends SessionStrategy = "jwt"> = T extends "jwt"
+  ? JWTString
+  : string
+
+/**
+ * Use secure cookies if the site uses HTTPS
+ * This being conditional allows cookies to work non-HTTPS development URLs
+ * Honour secure cookie option, which sets 'secure' and also adds '__Secure-'
+ * prefix, but enable them by default if the site URL is HTTPS; but not for
+ * non-HTTPS URLs like http://localhost which are used in development).
+ * For more on prefixes see https://googlechrome.github.io/samples/cookie-prefixes/
+ *
+ * @TODO Review cookie settings (names, options)
+ */
+export function defaultCookies(useSecureCookies: boolean): CookiesOptions {
+  const cookiePrefix = useSecureCookies ? "__Secure-" : ""
+  return {
+    // default cookie options
+    sessionToken: {
+      name: `${cookiePrefix}next-auth.session-token`,
+      options: {
+        httpOnly: true,
+        sameSite: "lax",
+        path: "/",
+        secure: useSecureCookies,
+      },
+    },
+    callbackUrl: {
+      name: `${cookiePrefix}next-auth.callback-url`,
+      options: {
+        sameSite: "lax",
+        path: "/",
+        secure: useSecureCookies,
+      },
+    },
+    csrfToken: {
+      // Default to __Host- for CSRF token for additional protection if using useSecureCookies
+      // NB: The `__Host-` prefix is stricter than the `__Secure-` prefix.
+      name: `${useSecureCookies ? "__Host-" : ""}next-auth.csrf-token`,
+      options: {
+        httpOnly: true,
+        sameSite: "lax",
+        path: "/",
+        secure: useSecureCookies,
+      },
+    },
+    pkceCodeVerifier: {
+      name: `${cookiePrefix}next-auth.pkce.code_verifier`,
+      options: {
+        httpOnly: true,
+        sameSite: "lax",
+        path: "/",
+        secure: useSecureCookies,
+      },
+    },
+    state: {
+      name: `${cookiePrefix}next-auth.state`,
+      options: {
+        httpOnly: true,
+        sameSite: "lax",
+        path: "/",
+        secure: useSecureCookies,
+      },
+    },
+  }
+}
+
+export interface Cookie extends CookieOption {
+  value: string
+}
+
+type Chunks = Record<string, string>
+
+export class SessionStore {
+  #chunks: Chunks = {}
+  #option: CookieOption
+  #logger: LoggerInstance | Console
+
+  constructor(
+    option: CookieOption,
+    req: {
+      cookies?: Record<string, string>
+      headers?: Record<string, string> | IncomingHttpHeaders
+    },
+    logger: LoggerInstance | Console
+  ) {
+    this.#logger = logger
+    this.#option = option
+
+    if (!req) return
+
+    for (const name in req.cookies) {
+      if (name.startsWith(option.name)) {
+        this.#chunks[name] = req.cookies[name]
+      }
+    }
+  }
+
+  get value() {
+    return Object.values(this.#chunks)?.join("")
+  }
+
+  /** Given a cookie, return a list of cookies, chunked to fit the allowed cookie size. */
+  #chunk(cookie: Cookie): Cookie[] {
+    const chunkCount = Math.ceil(cookie.value.length / CHUNK_SIZE)
+
+    if (chunkCount === 1) {
+      this.#chunks[cookie.name] = cookie.value
+      return [cookie]
+    }
+
+    const cookies: Cookie[] = []
+    for (let i = 0; i < chunkCount; i++) {
+      const name = `${cookie.name}.${i}`
+      const value = cookie.value.substr(i * CHUNK_SIZE, CHUNK_SIZE)
+      cookies.push({ ...cookie, name, value })
+      this.#chunks[name] = value
+    }
+
+    this.#logger.debug("CHUNKING_SESSION_COOKIE", {
+      message: `Session cookie exceeds allowed ${ALLOWED_COOKIE_SIZE} bytes.`,
+      emptyCookieSize: ESTIMATED_EMPTY_COOKIE_SIZE,
+      valueSize: cookie.value.length,
+      chunks: cookies.map((c) => c.value.length + ESTIMATED_EMPTY_COOKIE_SIZE),
+    })
+
+    return cookies
+  }
+
+  /** Returns cleaned cookie chunks. */
+  #clean(): Record<string, Cookie> {
+    const cleanedChunks: Record<string, Cookie> = {}
+    for (const name in this.#chunks) {
+      delete this.#chunks?.[name]
+      cleanedChunks[name] = {
+        name,
+        value: "",
+        options: { ...this.#option.options, maxAge: 0 },
+      }
+    }
+    return cleanedChunks
+  }
+
+  /**
+   * Given a cookie value, return new cookies, chunked, to fit the allowed cookie size.
+   * If the cookie has changed from chunked to unchunked or vice versa,
+   * it deletes the old cookies as well.
+   */
+  chunk(value: string, options: Partial<Cookie["options"]>): Cookie[] {
+    // Assume all cookies should be cleaned by default
+    const cookies: Record<string, Cookie> = this.#clean()
+
+    // Calculate new chunks
+    const chunked = this.#chunk({
+      name: this.#option.name,
+      value,
+      options: { ...this.#option.options, ...options },
+    })
+
+    // Update stored chunks / cookies
+    for (const chunk of chunked) {
+      cookies[chunk.name] = chunk
+    }
+
+    return Object.values(cookies)
+  }
+
+  /** Returns a list of cookies that should be cleaned. */
+  clean(): Cookie[] {
+    return Object.values(this.#clean())
+  }
+}

src/core/lib/csrf-token.ts

@@ -1,6 +1,12 @@
 import { createHash, randomBytes } from "crypto"
-import { NextAuthRequest, NextAuthResponse } from "../../lib/types"
-import * as cookie from "./cookie"
+import { InternalOptions } from "../../lib/types"
+
+interface CreateCSRFTokenParams {
+  options: InternalOptions
+  cookieValue?: string
+  isPost: boolean
+  bodyValue?: string
+}
 
 /**
  * Ensure CSRF Token cookie is set for any subsequent requests.
@@ -16,41 +22,33 @@ import * as cookie from "./cookie"
  * https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#double-submit-cookie
  * https://owasp.org/www-chapter-london/assets/slides/David_Johansson-Double_Defeat_of_Double-Submit_Cookie.pdf
  */
-export default function csrfTokenHandler(
-  req: NextAuthRequest,
-  res: NextAuthResponse
-) {
-  const { cookies, secret } = req.options
-  if (cookies.csrfToken.name in req.cookies) {
-    const [csrfToken, csrfTokenHash] =
-      req.cookies[cookies.csrfToken.name].split("|")
+export function createCSRFToken({
+  options,
+  cookieValue,
+  isPost,
+  bodyValue,
+}: CreateCSRFTokenParams) {
+  if (cookieValue) {
+    const [csrfToken, csrfTokenHash] = cookieValue.split("|")
     const expectedCsrfTokenHash = createHash("sha256")
-      .update(`${csrfToken}${secret}`)
+      .update(`${csrfToken}${options.secret}`)
       .digest("hex")
     if (csrfTokenHash === expectedCsrfTokenHash) {
       // If hash matches then we trust the CSRF token value
       // If this is a POST request and the CSRF Token in the POST request matches
       // the cookie we have already verified is the one we have set, then the token is verified!
-      const csrfTokenVerified =
-        req.method === "POST" && csrfToken === req.body.csrfToken
-      req.options.csrfToken = csrfToken
-      req.options.csrfTokenVerified = csrfTokenVerified
-      return
+      const csrfTokenVerified = isPost && csrfToken === bodyValue
+
+      return { csrfTokenVerified, csrfToken }
     }
   }
-  // If no csrfToken from cookie - because it's not been set yet,
-  // or because the hash doesn't match (e.g. because it's been modifed or because the secret has changed)
-  // create a new token.
+
+  // New CSRF token
   const csrfToken = randomBytes(32).toString("hex")
   const csrfTokenHash = createHash("sha256")
-    .update(`${csrfToken}${secret}`)
+    .update(`${csrfToken}${options.secret}`)
     .digest("hex")
-  const csrfTokenCookie = `${csrfToken}|${csrfTokenHash}`
-  cookie.set(
-    res,
-    cookies.csrfToken.name,
-    csrfTokenCookie,
-    cookies.csrfToken.options
-  )
-  req.options.csrfToken = csrfToken
+  const cookie = `${csrfToken}|${csrfTokenHash}`
+
+  return { cookie, csrfToken }
 }

src/core/lib/default-callbacks.ts

@@ -6,6 +6,7 @@ export const defaultCallbacks: CallbacksOptions = {
   },
   redirect({ url, baseUrl }) {
     if (url.startsWith(baseUrl)) return url
+    else if (url.startsWith("/")) return new URL(url, baseUrl).toString()
     return baseUrl
   },
   session({ session }) {

src/core/lib/email/signin.ts

@@ -1,6 +1,5 @@
 import { randomBytes } from "crypto"
-import { EmailConfig } from "src/providers"
-import { InternalOptions, InternalProvider } from "src/lib/types"
+import { InternalOptions } from "../../../lib/types"
 import { hashToken } from "../utils"
 
 /**
@@ -9,9 +8,9 @@ import { hashToken } from "../utils"
  */
 export default async function email(
   identifier: string,
-  options: InternalOptions<EmailConfig & InternalProvider>
+  options: InternalOptions<"email">
 ) {
-  const { baseUrl, basePath, adapter, provider, logger, callbackUrl } = options
+  const { url, adapter, provider, logger, callbackUrl } = options
 
   // Generate token
   const token =
@@ -33,7 +32,7 @@ export default async function email(
 
   // Generate a link with email, unhashed token and callback url
   const params = new URLSearchParams({ callbackUrl, token, email: identifier })
-  const url = `${baseUrl}${basePath}/callback/${provider.id}?${params}`
+  const _url = `${url}/callback/${provider.id}?${params}`
 
   try {
     // Send to user
@@ -41,14 +40,14 @@ export default async function email(
       identifier,
       token,
       expires,
-      url,
+      url: _url,
       provider,
     })
   } catch (error) {
     logger.error("SEND_VERIFICATION_EMAIL_ERROR", {
       identifier,
       url,
-      error,
+      error: error as Error,
     })
     throw new Error("SEND_VERIFICATION_EMAIL_ERROR")
   }

src/core/lib/oauth/authorization-url.ts

@@ -0,0 +1,79 @@
+import { openidClient } from "./client"
+import { oAuth1Client } from "./client-legacy"
+import { createState } from "./state-handler"
+import { createPKCE } from "./pkce-handler"
+
+import type { AuthorizationParameters } from "openid-client"
+import type { InternalOptions } from "../../../lib/types"
+import type { IncomingRequest } from "../.."
+import type { Cookie } from "../cookie"
+
+/**
+ *
+ * Generates an authorization/request token URL.
+ *
+ * [OAuth 2](https://www.oauth.com/oauth2-servers/authorization/the-authorization-request/) | [OAuth 1](https://oauth.net/core/1.0a/#auth_step2)
+ */
+export default async function getAuthorizationUrl(params: {
+  options: InternalOptions<"oauth">
+  query: IncomingRequest["query"]
+}) {
+  const { options, query } = params
+  const { logger, provider } = options
+  try {
+    let params: any = {}
+
+    if (typeof provider.authorization === "string") {
+      const parsedUrl = new URL(provider.authorization)
+      const parsedParams = Object.fromEntries(parsedUrl.searchParams.entries())
+      params = { ...params, ...parsedParams }
+    } else {
+      params = { ...params, ...provider.authorization?.params }
+    }
+
+    params = { ...params, ...query }
+
+    // Handle OAuth v1.x
+    if (provider.version?.startsWith("1.")) {
+      const client = oAuth1Client(options)
+      const tokens = (await client.getOAuthRequestToken(params)) as any
+      const url = `${
+        // @ts-expect-error
+        provider.authorization?.url ?? provider.authorization
+      }?${new URLSearchParams({
+        oauth_token: tokens.oauth_token,
+        oauth_token_secret: tokens.oauth_token_secret,
+        ...tokens.params,
+      })}`
+
+      logger.debug("GET_AUTHORIZATION_URL", { url })
+      return { redirect: url }
+    }
+
+    const client = await openidClient(options)
+
+    const authorizationParams: AuthorizationParameters = params
+    const cookies: Cookie[] = []
+
+    const state = await createState(options)
+    if (state) {
+      authorizationParams.state = state.value
+      cookies.push(state.cookie)
+    }
+
+    const pkce = await createPKCE(options)
+    if (pkce) {
+      authorizationParams.code_challenge = pkce.code_challenge
+      authorizationParams.code_challenge_method = pkce.code_challenge_method
+      cookies.push(pkce.cookie)
+    }
+
+    const url = client.authorizationUrl(authorizationParams)
+
+    logger.debug("GET_AUTHORIZATION_URL", { url, cookies })
+    return { redirect: url, cookies }
+  } catch (error) {
+    logger.error("GET_AUTHORIZATION_URL_ERROR", error as Error)
+    throw error
+  }
+}

src/core/lib/oauth/callback.ts

@@ -1,27 +1,34 @@
+import { TokenSet } from "openid-client"
 import { openidClient } from "./client"
 import { oAuth1Client } from "./client-legacy"
-import { getState } from "./state-handler"
+import { useState } from "./state-handler"
 import { usePKCECodeVerifier } from "./pkce-handler"
 import { OAuthCallbackError } from "../../errors"
-import { TokenSet } from "openid-client"
-import { Account, LoggerInstance, Profile } from "src"
-import { OAuthChecks, OAuthConfig } from "src/providers"
 
-export default async function oAuthCallback(
-  req,
-  res
-): Promise<GetProfileResult> {
-  const { logger } = req.options
+import type { CallbackParamsType } from "openid-client"
+import type { Account, LoggerInstance, Profile } from "../../.."
+import type { OAuthChecks, OAuthConfig } from "../../../providers"
+import type { InternalOptions } from "../../../lib/types"
+import type { IncomingRequest, OutgoingResponse } from "../.."
+import type { Cookie } from "../cookie"
 
-  /** @type {import("src/providers").OAuthConfig} */
-  const provider = req.options.provider
+export default async function oAuthCallback(params: {
+  options: InternalOptions<"oauth">
+  query: IncomingRequest["query"]
+  body: IncomingRequest["body"]
+  method: Required<IncomingRequest>["method"]
+  cookies: IncomingRequest["cookies"]
+}): Promise<GetProfileResult & { cookies?: OutgoingResponse["cookies"] }> {
+  const { options, query, body, method, cookies } = params
+  const { logger, provider } = options
 
-  const errorMessage = req.body.error ?? req.query.error
+  const errorMessage = body?.error ?? query?.error
   if (errorMessage) {
     const error = new Error(errorMessage)
     logger.error("OAUTH_CALLBACK_HANDLER_ERROR", {
       error,
-      body: req.body,
+      error_description: query?.error_description,
+      body,
       providerId: provider.id,
     })
     throw error
@@ -29,19 +36,19 @@ export default async function oAuthCallback(
 
   if (provider.version?.startsWith("1.")) {
     try {
-      const client = await oAuth1Client(req.options)
+      const client = await oAuth1Client(options)
       // Handle OAuth v1.x
-      const { oauth_token, oauth_verifier } = req.query
+      const { oauth_token, oauth_verifier } = query ?? {}
       // @ts-expect-error
       const tokens: TokenSet = await client.getOAuthAccessToken(
-        oauth_token,
+        oauth_token as string,
         // @ts-expect-error
         null,
         oauth_verifier
       )
       // @ts-expect-error
       let profile: Profile = await client.get(
-        provider.profileUrl,
+        (provider as any).profileUrl,
         tokens.oauth_token,
         tokens.oauth_token_secret
       )
@@ -52,24 +59,49 @@ export default async function oAuthCallback(
 
       return await getProfile({ profile, tokens, provider, logger })
     } catch (error) {
-      logger.error("OAUTH_V1_GET_ACCESS_TOKEN_ERROR", error)
+      logger.error("OAUTH_V1_GET_ACCESS_TOKEN_ERROR", error as Error)
       throw error
     }
   }
 
   try {
-    const client = await openidClient(req.options)
+    const client = await openidClient(options)
 
-    /** @type {import("openid-client").TokenSet} */
-    let tokens
+    let tokens: TokenSet
 
-    const checks: OAuthChecks = {
-      code_verifier: await usePKCECodeVerifier(req, res),
-      state: getState(req),
+    const checks: OAuthChecks = {}
+    const resCookies: Cookie[] = []
+
+    const state = await useState(cookies?.[options.cookies.state.name], options)
+
+    if (state) {
+      checks.state = state.value
+      resCookies.push(state.cookie)
     }
-    const params = { ...client.callbackParams(req), ...provider.token?.params }
 
+    const codeVerifier = cookies?.[options.cookies.pkceCodeVerifier.name]
+    const pkce = await usePKCECodeVerifier(codeVerifier, options)
+    if (pkce) {
+      checks.code_verifier = pkce.codeVerifier
+      resCookies.push(pkce.cookie)
+    }
+
+    const params: CallbackParamsType = {
+      ...client.callbackParams({
+        url: `http://n?${new URLSearchParams(query)}`,
+        // TODO: Ask to allow object to be passed upstream:
+        // https://github.com/panva/node-openid-client/blob/3ae206dfc78c02134aa87a07f693052c637cab84/types/index.d.ts#L439
+        // @ts-expect-error
+        body,
+        method,
+      }),
+      // @ts-expect-error
+      ...provider.token?.params,
+    }
+
+    // @ts-expect-error
     if (provider.token?.request) {
+      // @ts-expect-error
       const response = await provider.token.request({
         provider,
         params,
@@ -89,7 +121,9 @@ export default async function oAuthCallback(
     }
 
     let profile: Profile
+    // @ts-expect-error
     if (provider.userinfo?.request) {
+      // @ts-expect-error
       profile = await provider.userinfo.request({
         provider,
         tokens,
@@ -99,25 +133,31 @@ export default async function oAuthCallback(
       profile = tokens.claims()
     } else {
       profile = await client.userinfo(tokens, {
+        // @ts-expect-error
         params: provider.userinfo?.params,
       })
     }
 
-    // If a user object is supplied (e.g. Apple provider) add it to the profile object
-    // TODO: Remove/extract to Apple provider?
-    profile.user = JSON.parse(req.body.user ?? req.query.user ?? null)
-
-    return await getProfile({ profile, provider, tokens, logger })
+    const profileResult = await getProfile({
+      profile,
+      provider,
+      tokens,
+      logger,
+    })
+    return { ...profileResult, cookies: resCookies }
   } catch (error) {
-    logger.error("OAUTH_CALLBACK_ERROR", { error, providerId: provider.id })
-    throw new OAuthCallbackError(error)
+    logger.error("OAUTH_CALLBACK_ERROR", {
+      error: error as Error,
+      providerId: provider.id,
+    })
+    throw new OAuthCallbackError(error as Error)
   }
 }
 
 export interface GetProfileParams {
   profile: Profile
   tokens: TokenSet
-  provider: OAuthConfig
+  provider: OAuthConfig<any>
   logger: LoggerInstance
 }
 
@@ -159,7 +199,10 @@ async function getProfile({
     // all providers, so we return an empty object; the user should then be
     // redirected back to the sign up page. We log the error to help developers
     // who might be trying to debug this when configuring a new provider.
-    logger.error("OAUTH_PARSE_PROFILE_ERROR", { error, OAuthProfile })
+    logger.error("OAUTH_PARSE_PROFILE_ERROR", {
+      error: error as Error,
+      OAuthProfile,
+    })
     return {
       profile: null,
       account: null,

src/core/lib/oauth/client-legacy.ts

@@ -2,29 +2,29 @@
 // We have the intentions to provide only minor fixes for this in the future.
 
 import { OAuth } from "oauth"
+import { InternalOptions } from "src/lib/types"
 
 /**
  * Client supporting OAuth 1.x
- * @param {import("src/lib/types").InternalOptions} options
  */
-export function oAuth1Client(options) {
-  /** @type {import("src/providers").OAuthConfig} */
+export function oAuth1Client(options: InternalOptions<"oauth">) {
   const provider = options.provider
 
   const oauth1Client = new OAuth(
-    provider.requestTokenUrl,
-    provider.accessTokenUrl,
-    provider.clientId,
-    provider.clientSecret,
-    provider.version || "1.0",
+    provider.requestTokenUrl as string,
+    provider.accessTokenUrl as string,
+    provider.clientId as string,
+    provider.clientSecret as string,
+    provider.version ?? "1.0",
     provider.callbackUrl,
-    provider.encoding || "HMAC-SHA1"
+    provider.encoding ?? "HMAC-SHA1"
   )
 
   // Promisify get()  for OAuth1
   const originalGet = oauth1Client.get.bind(oauth1Client)
-  oauth1Client.get = (...args) => {
-    return new Promise((resolve, reject) => {
+  // @ts-expect-error
+  oauth1Client.get = async (...args) => {
+    return await new Promise((resolve, reject) => {
       originalGet(...args, (error, result) => {
         if (error) {
           return reject(error)
@@ -36,15 +36,15 @@ export function oAuth1Client(options) {
   // Promisify getOAuth1AccessToken()  for OAuth1
   const originalGetOAuth1AccessToken =
     oauth1Client.getOAuthAccessToken.bind(oauth1Client)
-  oauth1Client.getOAuthAccessToken = (...args) => {
-    return new Promise((resolve, reject) => {
+  oauth1Client.getOAuthAccessToken = async (...args: any[]) => {
+    return await new Promise((resolve, reject) => {
       originalGetOAuth1AccessToken(
         ...args,
-        (error, oauth_token, oauth_token_secret) => {
+        (error: any, oauth_token: any, oauth_token_secret: any) => {
           if (error) {
             return reject(error)
           }
-          resolve({ oauth_token, oauth_token_secret })
+          resolve({ oauth_token, oauth_token_secret } as any)
         }
       )
     })
@@ -52,15 +52,15 @@ export function oAuth1Client(options) {
 
   const originalGetOAuthRequestToken =
     oauth1Client.getOAuthRequestToken.bind(oauth1Client)
-  oauth1Client.getOAuthRequestToken = (params = {}) => {
-    return new Promise((resolve, reject) => {
+  oauth1Client.getOAuthRequestToken = async (params = {}) => {
+    return await new Promise((resolve, reject) => {
       originalGetOAuthRequestToken(
         params,
         (error, oauth_token, oauth_token_secret, params) => {
           if (error) {
             return reject(error)
           }
-          resolve({ oauth_token, oauth_token_secret, params })
+          resolve({ oauth_token, oauth_token_secret, params } as any)
         }
       )
     })

src/core/lib/oauth/client.ts

@@ -0,0 +1,50 @@
+import { Issuer, Client, custom } from "openid-client"
+import { InternalOptions } from "src/lib/types"
+
+/**
+ * NOTE: We can add auto discovery of the provider's endpoint
+ * that requires only one endpoint to be specified by the user.
+ * Check out `Issuer.discover`
+ *
+ * Client supporting OAuth 2.x and OIDC
+ */
+export async function openidClient(
+  options: InternalOptions<"oauth">
+): Promise<Client> {
+  const provider = options.provider
+  
+  if (provider.httpOptions) custom.setHttpOptionsDefaults(provider.httpOptions)
+  
+  let issuer: Issuer
+  if (provider.wellKnown) {
+    issuer = await Issuer.discover(provider.wellKnown)
+  } else {
+    issuer = new Issuer({
+      issuer: provider.issuer as string,
+      authorization_endpoint:
+        // @ts-expect-error
+        provider.authorization?.url ?? provider.authorization,
+      // @ts-expect-error
+      token_endpoint: provider.token?.url ?? provider.token,
+      // @ts-expect-error
+      userinfo_endpoint: provider.userinfo?.url ?? provider.userinfo,
+    })
+  }
+
+  const client = new issuer.Client(
+    {
+      client_id: provider.clientId as string,
+      client_secret: provider.clientSecret as string,
+      redirect_uris: [provider.callbackUrl],
+      ...provider.client,
+    },
+    provider.jwks
+  )
+
+  // allow a 10 second skew
+  // See https://github.com/nextauthjs/next-auth/issues/3032
+  // and https://github.com/nextauthjs/next-auth/issues/3067
+  client[custom.clock_tolerance] = 10
+
+  return client
+}

src/core/lib/oauth/pkce-handler.ts

@@ -0,0 +1,84 @@
+import * as jwt from "../../../jwt"
+import { generators } from "openid-client"
+import type { InternalOptions } from "src/lib/types"
+import type { Cookie } from "../cookie"
+
+const PKCE_CODE_CHALLENGE_METHOD = "S256"
+const PKCE_MAX_AGE = 60 * 15 // 15 minutes in seconds
+
+/**
+ * Returns `code_challenge` and `code_challenge_method`
+ * and saves them in a cookie.
+ */
+export async function createPKCE(options: InternalOptions<"oauth">): Promise<
+  | undefined
+  | {
+      code_challenge: string
+      code_challenge_method: "S256"
+      cookie: Cookie
+    }
+> {
+  const { cookies, logger, provider } = options
+  if (!provider.checks?.includes("pkce")) {
+    // Provider does not support PKCE, return nothing.
+    return
+  }
+  const code_verifier = generators.codeVerifier()
+  const code_challenge = generators.codeChallenge(code_verifier)
+
+  const expires = new Date()
+  expires.setTime(expires.getTime() + PKCE_MAX_AGE * 1000)
+
+  // Encrypt code_verifier and save it to an encrypted cookie
+  const encryptedCodeVerifier = await jwt.encode({
+    ...options.jwt,
+    maxAge: PKCE_MAX_AGE,
+    token: { code_verifier },
+  })
+
+  logger.debug("CREATE_PKCE_CHALLENGE_VERIFIER", {
+    code_challenge,
+    code_challenge_method: PKCE_CODE_CHALLENGE_METHOD,
+    code_verifier,
+    PKCE_MAX_AGE,
+  })
+
+  return {
+    code_challenge,
+    code_challenge_method: PKCE_CODE_CHALLENGE_METHOD,
+    cookie: {
+      name: cookies.pkceCodeVerifier.name,
+      value: encryptedCodeVerifier,
+      options: { ...cookies.pkceCodeVerifier.options, expires },
+    },
+  }
+}
+
+/**
+ * Returns code_verifier if provider uses PKCE,
+ * and clears the container cookie afterwards.
+ */
+export async function usePKCECodeVerifier(
+  codeVerifier: string | undefined,
+  options: InternalOptions<"oauth">
+): Promise<{ codeVerifier: string; cookie: Cookie } | undefined> {
+  const { cookies, provider } = options
+
+  if (!provider?.checks?.includes("pkce") || !codeVerifier) {
+    return
+  }
+
+  const pkce = (await jwt.decode({
+    ...options.jwt,
+    token: codeVerifier,
+  })) as any
+
+  return {
+    codeVerifier: pkce?.code_verifier ?? undefined,
+    cookie: {
+      name: cookies.pkceCodeVerifier.name,
+      value: "",
+      options: { ...cookies.pkceCodeVerifier.options, maxAge: 0 },
+    },
+  }
+}

src/core/lib/oauth/state-handler.ts

@@ -0,0 +1,63 @@
+import { generators } from "openid-client"
+
+import type { InternalOptions } from "src/lib/types"
+import type { Cookie } from "../cookie"
+
+const STATE_MAX_AGE = 60 * 15 // 15 minutes in seconds
+
+/** Returns state if the provider supports it */
+export async function createState(
+  options: InternalOptions<"oauth">
+): Promise<{ cookie: Cookie; value: string } | undefined> {
+  const { logger, provider, jwt, cookies } = options
+
+  if (!provider.checks?.includes("state")) {
+    // Provider does not support state, return nothing
+    return
+  }
+
+  const state = generators.state()
+
+  const encodedState = await jwt.encode({
+    ...jwt,
+    maxAge: STATE_MAX_AGE,
+    token: { state },
+  })
+
+  logger.debug("CREATE_STATE", { state, maxAge: STATE_MAX_AGE })
+
+  const expires = new Date()
+  expires.setTime(expires.getTime() + STATE_MAX_AGE * 1000)
+  return {
+    value: state,
+    cookie: {
+      name: cookies.state.name,
+      value: encodedState,
+      options: { ...cookies.state.options, expires },
+    },
+  }
+}
+
+/**
+ * Returns state from if the provider supports states,
+ * and clears the container cookie afterwards.
+ */
+export async function useState(
+  state: string | undefined,
+  options: InternalOptions<"oauth">
+): Promise<{ value: string; cookie: Cookie } | undefined> {
+  const { cookies, provider, jwt } = options
+
+  if (!provider.checks?.includes("state") || !state) return
+
+  const value = (await jwt.decode({ ...options.jwt, token: state })) as any
+
+  return {
+    value: value?.state ?? undefined,
+    cookie: {
+      name: cookies.state.name,
+      value: "",
+      options: { ...cookies.pkceCodeVerifier.options, maxAge: 0 },
+    },
+  }
+}

src/core/lib/providers.ts

@@ -0,0 +1,73 @@
+import { merge } from "../../lib/merge"
+
+import type { InternalProvider } from "../../lib/types"
+import type { Provider } from "../../providers"
+import type { InternalUrl } from "../../lib/parse-url"
+
+/**
+ * Adds `signinUrl` and `callbackUrl` to each provider
+ * and deep merge user-defined options.
+ */
+export default function parseProviders(params: {
+  providers: Provider[]
+  url: InternalUrl
+  providerId?: string
+}): {
+  providers: InternalProvider[]
+  provider?: InternalProvider
+} {
+  const { url, providerId } = params
+
+  const providers = params.providers.map(({ options, ...rest }) => {
+    const defaultOptions = normalizeProvider(rest as Provider)
+    const userOptions = normalizeProvider(options as Provider)
+
+    return merge(defaultOptions, {
+      ...userOptions,
+      signinUrl: `${url}/signin/${userOptions?.id ?? rest.id}`,
+      callbackUrl: `${url}/callback/${userOptions?.id ?? rest.id}`,
+    })
+  })
+
+  const provider = providers.find(({ id }) => id === providerId)
+
+  return { providers, provider }
+}
+
+function normalizeProvider(provider?: Provider) {
+  if (!provider) return
+
+  const normalized: InternalProvider = Object.entries(
+    provider
+  ).reduce<InternalProvider>((acc, [key, value]) => {
+    if (
+      ["authorization", "token", "userinfo"].includes(key) &&
+      typeof value === "string"
+    ) {
+      const url = new URL(value)
+      acc[key] = {
+        url: `${url.origin}${url.pathname}`,
+        params: Object.fromEntries(url.searchParams ?? []),
+      }
+    } else {
+      acc[key] = value
+    }
+
+    return acc
+    // eslint-disable-next-line @typescript-eslint/prefer-reduce-type-parameter, @typescript-eslint/consistent-type-assertions
+  }, {} as any)
+
+  if (normalized.type === "oauth" && !normalized.version?.startsWith("1.")) {
+    // If provider has as an "openid-configuration" well-known endpoint
+    // or an "openid" scope request, it will also likely be able to receive an `id_token`
+    normalized.idToken = Boolean(
+      normalized.idToken ??
+        normalized.wellKnown?.includes("openid-configuration") ??
+        // @ts-expect-error
+        normalized.authorization?.params?.scope?.includes("openid")
+    )
+
+    if (!normalized.checks) normalized.checks = ["state"]
+  }
+  return normalized
+}

src/core/lib/utils.ts

@@ -1,21 +1,18 @@
 import { createHash } from "crypto"
 import { NextAuthOptions } from "../.."
-import { EmailConfig } from "../../providers"
-import { InternalOptions, InternalProvider } from "../../lib/types"
+import { InternalOptions } from "../../lib/types"
+import { InternalUrl } from "../../lib/parse-url"
 
 /**
  * Takes a number in seconds and returns the date in the future.
  * Optionally takes a second date parameter. In that case
  * the date in the future will be calculated from that date instead of now.
  */
-export function fromDate(time, date = Date.now()) {
+export function fromDate(time: number, date = Date.now()) {
   return new Date(date + time * 1000)
 }
 
-export function hashToken(
-  token: string,
-  options: InternalOptions<EmailConfig & InternalProvider>
-) {
+export function hashToken(token: string, options: InternalOptions<"email">) {
   const { provider, secret } = options
   return (
     createHash("sha256")
@@ -28,28 +25,18 @@ export function hashToken(
 /**
  * Secret used salt cookies and tokens (e.g. for CSRF protection).
  * If no secret option is specified then it creates one on the fly
- * based on options passed here. A options contains unique data, such as
- * OAuth provider secrets and database credentials it should be sufficent.
- */
-export default function createSecret({
-  userOptions,
-  basePath,
-  baseUrl,
-}: {
+ * based on options passed here. If options contains unique data, such as
+ * OAuth provider secrets and database credentials it should be sufficent. If no secret provided in production, we throw an error. */
+export default function createSecret(params: {
   userOptions: NextAuthOptions
-  basePath: string
-  baseUrl: string
+  url: InternalUrl
 }) {
+  const { userOptions, url } = params
+
   return (
     userOptions.secret ??
     createHash("sha256")
-      .update(
-        JSON.stringify({
-          baseUrl,
-          basePath,
-          ...userOptions,
-        })
-      )
+      .update(JSON.stringify({ ...url, ...userOptions }))
       .digest("hex")
   )
 }

src/core/pages/error.tsx

@@ -0,0 +1,114 @@
+import { Theme } from "../.."
+import { InternalUrl } from "../../lib/parse-url"
+
+/**
+ * The following errors are passed as error query parameters to the default or overridden error page.
+ *
+ * [Documentation](https://next-auth.js.org/configuration/pages#error-page) */
+export type ErrorType =
+  | "default"
+  | "configuration"
+  | "accessdenied"
+  | "verification"
+
+export interface ErrorProps {
+  url?: InternalUrl
+  theme?: Theme
+  error?: ErrorType
+}
+
+interface ErrorView {
+  status: number
+  heading: string
+  message: JSX.Element
+  signin?: JSX.Element
+}
+
+/** Renders an error page. */
+export default function ErrorPage(props: ErrorProps) {
+  const { url, error = "default", theme } = props
+  const signinPageUrl = `${url}/signin`
+
+  const errors: Record<ErrorType, ErrorView> = {
+    default: {
+      status: 200,
+      heading: "Error",
+      message: (
+        <p>
+          <a className="site" href={url?.origin}>
+            {url?.host}
+          </a>
+        </p>
+      ),
+    },
+    configuration: {
+      status: 500,
+      heading: "Server error",
+      message: (
+        <div>
+          <p>There is a problem with the server configuration.</p>
+          <p>Check the server logs for more information.</p>
+        </div>
+      ),
+    },
+    accessdenied: {
+      status: 403,
+      heading: "Access Denied",
+      message: (
+        <div>
+          <p>You do not have permission to sign in.</p>
+          <p>
+            <a className="button" href={signinPageUrl}>
+              Sign in
+            </a>
+          </p>
+        </div>
+      ),
+    },
+    verification: {
+      status: 403,
+      heading: "Unable to sign in",
+      message: (
+        <div>
+          <p>The sign in link is no longer valid.</p>
+          <p>It may have been used already or it may have expired.</p>
+        </div>
+      ),
+      signin: (
+        <p>
+          <a className="button" href={signinPageUrl}>
+            Sign in
+          </a>
+        </p>
+      ),
+    },
+  }
+
+  const { status, heading, message, signin } =
+    errors[error.toLowerCase()] ?? errors.default
+
+  return {
+    status,
+    html: (
+      <div className="error">
+        {theme?.brandColor && (
+          <style
+            dangerouslySetInnerHTML={{
+              __html: `
+        :root {
+          --brand-color: ${theme?.brandColor}
+        }
+      `,
+            }}
+          />
+        )}
+        {theme?.logo && <img src={theme.logo} alt="Logo" className="logo" />}
+        <div className="card">
+          <h1>{heading}</h1>
+          <div className="message">{message}</div>
+          {signin}
+        </div>
+      </div>
+    ),
+  }
+}

src/core/pages/index.ts

@@ -0,0 +1,79 @@
+import renderToString from "preact-render-to-string"
+import SigninPage from "./signin"
+import SignoutPage from "./signout"
+import VerifyRequestPage from "./verify-request"
+import ErrorPage from "./error"
+import css from "../../css"
+
+import type { InternalOptions } from "../../lib/types"
+import type { IncomingRequest, OutgoingResponse } from ".."
+import type { Cookie } from "../lib/cookie"
+import type { ErrorType } from "./error"
+
+type RenderPageParams = {
+  query?: IncomingRequest["query"]
+  cookies?: Cookie[]
+} & Partial<
+  Pick<
+    InternalOptions,
+    "url" | "callbackUrl" | "csrfToken" | "providers" | "theme"
+  >
+>
+
+/**
+ * Unless the user defines their [own pages](https://next-auth.js.org/configuration/pages),
+ * we render a set of default ones, using Preact SSR.
+ */
+export default function renderPage(params: RenderPageParams) {
+  const { url, theme, query, cookies } = params
+
+  function send({ html, title, status }: any): OutgoingResponse {
+    return {
+      cookies,
+      status,
+      headers: [{ key: "Content-Type", value: "text/html" }],
+      body: `<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><style>${css()}</style><title>${title}</title></head><body class="__next-auth-theme-${
+        theme?.colorScheme ?? "auto"
+      }"><div class="page">${renderToString(html)}</div></body></html>`,
+    }
+  }
+
+  return {
+    signin(props?: any) {
+      return send({
+        html: SigninPage({
+          csrfToken: params.csrfToken,
+          providers: params.providers,
+          callbackUrl: params.callbackUrl,
+          theme,
+          ...query,
+          ...props,
+        }),
+        title: "Sign In",
+      })
+    },
+    signout(props?: any) {
+      return send({
+        html: SignoutPage({
+          csrfToken: params.csrfToken,
+          url,
+          theme,
+          ...props,
+        }),
+        title: "Sign Out",
+      })
+    },
+    verifyRequest(props?: any) {
+      return send({
+        html: VerifyRequestPage({ url, theme, ...props }),
+        title: "Verify Request",
+      })
+    },
+    error(props?: { error?: ErrorType }) {
+      return send({
+        ...ErrorPage({ url, theme, ...props }),
+        title: "Error",
+      })
+    },
+  }
+}

src/core/pages/signin.tsx

@@ -0,0 +1,168 @@
+import { Theme } from "../.."
+import { InternalProvider } from "../../lib/types"
+
+/**
+ * The following errors are passed as error query parameters to the default or overridden sign-in page.
+ *
+ * [Documentation](https://next-auth.js.org/configuration/pages#sign-in-page) */
+export type SignInErrorTypes =
+  | "Signin"
+  | "OAuthSignin"
+  | "OAuthCallback"
+  | "OAuthCreateAccount"
+  | "EmailCreateAccount"
+  | "Callback"
+  | "OAuthAccountNotLinked"
+  | "EmailSignin"
+  | "CredentialsSignin"
+  | "SessionRequired"
+  | "default"
+
+export interface SignInServerPageParams {
+  csrfToken: string
+  providers: InternalProvider[]
+  callbackUrl: string
+  email: string
+  error: SignInErrorTypes
+  theme: Theme
+}
+
+export default function SigninPage(props: SignInServerPageParams) {
+  const {
+    csrfToken,
+    providers,
+    callbackUrl,
+    theme,
+    email,
+    error: errorType,
+  } = props
+  // We only want to render providers
+  const providersToRender = providers.filter((provider) => {
+    if (provider.type === "oauth" || provider.type === "email") {
+      // Always render oauth and email type providers
+      return true
+    } else if (provider.type === "credentials" && provider.credentials) {
+      // Only render credentials type provider if credentials are defined
+      return true
+    }
+    // Don't render other provider types
+    return false
+  })
+
+  if (typeof document !== "undefined" && theme.brandColor) {
+    document.documentElement.style.setProperty(
+      "--brand-color",
+      theme.brandColor
+    )
+  }
+
+  const errors: Record<SignInErrorTypes, string> = {
+    Signin: "Try signing in with a different account.",
+    OAuthSignin: "Try signing in with a different account.",
+    OAuthCallback: "Try signing in with a different account.",
+    OAuthCreateAccount: "Try signing in with a different account.",
+    EmailCreateAccount: "Try signing in with a different account.",
+    Callback: "Try signing in with a different account.",
+    OAuthAccountNotLinked:
+      "To confirm your identity, sign in with the same account you used originally.",
+    EmailSignin: "The e-mail could not be sent.",
+    CredentialsSignin:
+      "Sign in failed. Check the details you provided are correct.",
+    SessionRequired: "Please sign in to access this page.",
+    default: "Unable to sign in.",
+  }
+
+  const error = errorType && (errors[errorType] ?? errors.default)
+
+  return (
+    <div className="signin">
+      {theme.brandColor && (
+        <style
+          dangerouslySetInnerHTML={{
+            __html: `
+        :root {
+          --brand-color: ${theme.brandColor}
+        }
+      `,
+          }}
+        />
+      )}
+      {theme.logo && <img src={theme.logo} alt="Logo" className="logo" />}
+      <div className="card">
+        {error && (
+          <div className="error">
+            <p>{error}</p>
+          </div>
+        )}
+        {providersToRender.map((provider, i: number) => (
+          <div key={provider.id} className="provider">
+            {provider.type === "oauth" && (
+              <form action={provider.signinUrl} method="POST">
+                <input type="hidden" name="csrfToken" value={csrfToken} />
+                {callbackUrl && (
+                  <input type="hidden" name="callbackUrl" value={callbackUrl} />
+                )}
+                <button type="submit" className="button">
+                  Sign in with {provider.name}
+                </button>
+              </form>
+            )}
+            {(provider.type === "email" || provider.type === "credentials") &&
+              i > 0 &&
+              providersToRender[i - 1].type !== "email" &&
+              providersToRender[i - 1].type !== "credentials" && <hr />}
+            {provider.type === "email" && (
+              <form action={provider.signinUrl} method="POST">
+                <input type="hidden" name="csrfToken" value={csrfToken} />
+                <label
+                  className="section-header"
+                  htmlFor={`input-email-for-${provider.id}-provider`}
+                >
+                  Email
+                </label>
+                <input
+                  id={`input-email-for-${provider.id}-provider`}
+                  autoFocus
+                  type="text"
+                  name="email"
+                  value={email}
+                  placeholder="email@example.com"
+                />
+                <button type="submit">Sign in with {provider.name}</button>
+              </form>
+            )}
+            {provider.type === "credentials" && (
+              <form action={provider.callbackUrl} method="POST">
+                <input type="hidden" name="csrfToken" value={csrfToken} />
+                {Object.keys(provider.credentials).map((credential) => {
+                  return (
+                    <div key={`input-group-${provider.id}`}>
+                      <label
+                        className="section-header"
+                        htmlFor={`input-${credential}-for-${provider.id}-provider`}
+                      >
+                        {provider.credentials[credential].label ?? credential}
+                      </label>
+                      <input
+                        name={credential}
+                        id={`input-${credential}-for-${provider.id}-provider`}
+                        type={provider.credentials[credential].type ?? "text"}
+                        placeholder={
+                          provider.credentials[credential].placeholder ?? ""
+                        }
+                        {...provider.credentials[credential]}
+                      />
+                    </div>
+                  )
+                })}
+                <button type="submit">Sign in with {provider.name}</button>
+              </form>
+            )}
+            {(provider.type === "email" || provider.type === "credentials") &&
+              i + 1 < providersToRender.length && <hr />}
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}

src/core/pages/signout.tsx

@@ -0,0 +1,35 @@
+import { Theme } from "../.."
+import { InternalUrl } from "../../lib/parse-url"
+
+export interface SignoutProps {
+  url: InternalUrl
+  csrfToken: string
+  theme: Theme
+}
+
+export default function SignoutPage(props: SignoutProps) {
+  const { url, csrfToken, theme } = props
+
+  return (
+    <div className="signout">
+      { theme.brandColor && <style
+        dangerouslySetInnerHTML={{
+          __html: `
+        :root {
+          --brand-color: ${theme.brandColor}
+        }
+      `,
+        }}
+      /> }
+      {theme.logo && <img src={theme.logo} alt="Logo" className="logo" />}
+      <div className="card">
+        <h1>Signout</h1>
+        <p>Are you sure you want to sign out?</p>
+        <form action={`${url}/signout`} method="POST">
+          <input type="hidden" name="csrfToken" value={csrfToken} />
+          <button type="submit">Sign out</button>
+        </form>
+      </div>
+    </div>
+  )
+}

src/core/pages/verify-request.tsx

@@ -0,0 +1,35 @@
+import { Theme } from "../.."
+import { InternalUrl } from "../../lib/parse-url"
+
+interface VerifyRequestPageProps {
+  url: InternalUrl
+  theme: Theme
+}
+
+export default function VerifyRequestPage(props: VerifyRequestPageProps) {
+  const { url, theme } = props
+
+  return (
+    <div className="verify-request">
+      { theme.brandColor && <style
+        dangerouslySetInnerHTML={{
+          __html: `
+        :root {
+          --brand-color: ${theme.brandColor}
+        }
+      `,
+        }}
+      /> }
+      {theme.logo && <img src={theme.logo} alt="Logo" className="logo" />}
+      <div className="card">
+        <h1>Check your email</h1>
+        <p>A sign in link has been sent to your email address.</p>
+        <p>
+          <a className="site" href={url.origin}>
+            {url.host}
+          </a>
+        </p>
+      </div>
+    </div>
+  )
+}

src/core/routes/callback.ts

@@ -1,33 +1,57 @@
 import oAuthCallback from "../lib/oauth/callback"
 import callbackHandler from "../lib/callback-handler"
-import * as cookie from "../lib/cookie"
 import { hashToken } from "../lib/utils"
 
-/**
- * Handle callbacks from login services
- * @type {import("src/lib/types").NextAuthApiHandler}
- */
-export default async function callback(req, res) {
+import type { InternalOptions } from "../../lib/types"
+import type { IncomingRequest, OutgoingResponse } from ".."
+import type { Cookie, SessionStore } from "../lib/cookie"
+import type { User } from "../.."
+
+/** Handle callbacks from login services */
+export default async function callback(params: {
+  options: InternalOptions<"oauth" | "credentials" | "email">
+  query: IncomingRequest["query"]
+  method: Required<IncomingRequest>["method"]
+  body: IncomingRequest["body"]
+  headers: IncomingRequest["headers"]
+  cookies: IncomingRequest["cookies"]
+  sessionStore: SessionStore
+}): Promise<OutgoingResponse> {
+  const { options, query, body, method, headers, sessionStore } = params
   const {
     provider,
     adapter,
-    baseUrl,
-    basePath,
-    cookies,
+    url,
     callbackUrl,
     pages,
     jwt,
     events,
     callbacks,
-    session: { jwt: useJwtSession, maxAge: sessionMaxAge },
+    session: { strategy: sessionStrategy, maxAge: sessionMaxAge },
     logger,
-  } = req.options
+  } = options
 
-  const sessionToken = req.cookies?.[cookies.sessionToken.name] ?? null
+  const cookies: Cookie[] = []
+
+  const useJwtSession = sessionStrategy === "jwt"
 
   if (provider.type === "oauth") {
     try {
-      const { profile, account, OAuthProfile } = await oAuthCallback(req, res)
+      const {
+        profile,
+        account,
+        OAuthProfile,
+        cookies: oauthCookies,
+      } = await oAuthCallback({
+        query,
+        body,
+        method,
+        options,
+        cookies: params.cookies,
+      })
+
+      if (oauthCookies) cookies.push(...oauthCookies)
+
       try {
         // Make it easier to debug when adding a new provider
         logger.debug("OAUTH_CALLBACK_RESPONSE", {
@@ -45,7 +69,7 @@ export default async function callback(req, res) {
         // should at least be visible to developers what happened if it is an
         // error with the provider.
         if (!profile) {
-          return res.redirect(`${baseUrl}${basePath}/signin`)
+          return { redirect: `${url}/signin`, cookies }
         }
 
         // Check if user is allowed to sign in
@@ -56,6 +80,7 @@ export default async function callback(req, res) {
         if (adapter) {
           const { getUserByAccount } = adapter
           const userByAccount = await getUserByAccount({
+            // @ts-expect-error
             providerAccountId: account.providerAccountId,
             provider: provider.id,
           })
@@ -66,31 +91,33 @@ export default async function callback(req, res) {
         try {
           const isAllowed = await callbacks.signIn({
             user: userOrProfile,
+            // @ts-expect-error
             account,
             profile: OAuthProfile,
           })
           if (!isAllowed) {
-            return res.redirect(
-              `${baseUrl}${basePath}/error?error=AccessDenied`
-            )
+            return { redirect: `${url}/error?error=AccessDenied`, cookies }
           } else if (typeof isAllowed === "string") {
-            return res.redirect(isAllowed)
+            return { redirect: isAllowed, cookies }
           }
         } catch (error) {
-          return res.redirect(
-            `${baseUrl}${basePath}/error?error=${encodeURIComponent(
-              error.message
-            )}`
-          )
+          return {
+            redirect: `${url}/error?error=${encodeURIComponent(
+              (error as Error).message
+            )}`,
+            cookies,
+          }
         }
 
         // Sign user in
-        const { user, session, isNewUser } = await callbackHandler(
-          sessionToken,
+        // @ts-expect-error
+        const { user, session, isNewUser } = await callbackHandler({
+          sessionToken: sessionStore.value,
           profile,
+          // @ts-expect-error
           account,
-          req.options
-        )
+          options,
+        })
 
         if (useJwtSession) {
           const defaultToken = {
@@ -102,90 +129,90 @@ export default async function callback(req, res) {
           const token = await callbacks.jwt({
             token: defaultToken,
             user,
+            // @ts-expect-error
             account,
             profile: OAuthProfile,
             isNewUser,
           })
 
-          // Sign and encrypt token
-          const newEncodedJwt = await jwt.encode({ ...jwt, token })
+          // Encode token
+          const newToken = await jwt.encode({ ...jwt, token })
 
           // Set cookie expiry date
           const cookieExpires = new Date()
           cookieExpires.setTime(cookieExpires.getTime() + sessionMaxAge * 1000)
 
-          cookie.set(res, cookies.sessionToken.name, newEncodedJwt, {
-            expires: cookieExpires.toISOString(),
-            ...cookies.sessionToken.options,
+          const sessionCookies = sessionStore.chunk(newToken, {
+            expires: cookieExpires,
           })
+          cookies.push(...sessionCookies)
         } else {
           // Save Session Token in cookie
-          cookie.set(res, cookies.sessionToken.name, session.sessionToken, {
-            expires: session.expires,
-            ...cookies.sessionToken.options,
+          cookies.push({
+            name: options.cookies.sessionToken.name,
+            value: session.sessionToken,
+            options: {
+              ...options.cookies.sessionToken.options,
+              expires: session.expires,
+            },
           })
         }
 
+        // @ts-expect-error
         await events.signIn?.({ user, account, profile, isNewUser })
 
         // Handle first logins on new accounts
         // e.g. option to send users to a new account landing page on initial login
         // Note that the callback URL is preserved, so the journey can still be resumed
         if (isNewUser && pages.newUser) {
-          return res.redirect(
-            `${pages.newUser}${
+          return {
+            redirect: `${pages.newUser}${
               pages.newUser.includes("?") ? "&" : "?"
-            }callbackUrl=${encodeURIComponent(callbackUrl)}`
-          )
+            }callbackUrl=${encodeURIComponent(callbackUrl)}`,
+            cookies,
+          }
         }
 
         // Callback URL is already verified at this point, so safe to use if specified
-        return res.redirect(callbackUrl || baseUrl)
+        return { redirect: callbackUrl, cookies }
       } catch (error) {
-        if (error.name === "AccountNotLinkedError") {
+        if ((error as Error).name === "AccountNotLinkedError") {
           // If the email on the account is already linked, but not with this OAuth account
-          return res.redirect(
-            `${baseUrl}${basePath}/error?error=OAuthAccountNotLinked`
-          )
-        } else if (error.name === "CreateUserError") {
-          return res.redirect(
-            `${baseUrl}${basePath}/error?error=OAuthCreateAccount`
-          )
+          return {
+            redirect: `${url}/error?error=OAuthAccountNotLinked`,
+            cookies,
+          }
+        } else if ((error as Error).name === "CreateUserError") {
+          return { redirect: `${url}/error?error=OAuthCreateAccount`, cookies }
         }
-        logger.error("OAUTH_CALLBACK_HANDLER_ERROR", error)
-        return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
+        logger.error("OAUTH_CALLBACK_HANDLER_ERROR", error as Error)
+        return { redirect: `${url}/error?error=Callback`, cookies }
       }
     } catch (error) {
-      if (error.name === "OAuthCallbackError") {
-        logger.error("CALLBACK_OAUTH_ERROR", error)
-        return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
+      if ((error as Error).name === "OAuthCallbackError") {
+        logger.error("CALLBACK_OAUTH_ERROR", error as Error)
+        return { redirect: `${url}/error?error=OAuthCallback`, cookies }
       }
-      logger.error("OAUTH_CALLBACK_ERROR", error)
-      return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
+      logger.error("OAUTH_CALLBACK_ERROR", error as Error)
+      return { redirect: `${url}/error?error=Callback`, cookies }
     }
   } else if (provider.type === "email") {
     try {
-      if (!adapter) {
-        logger.error(
-          "EMAIL_REQUIRES_ADAPTER_ERROR",
-          new Error("E-mail login requires an adapter but it was undefined")
-        )
-        return res.redirect(`${baseUrl}${basePath}/error?error=Configuration`)
-      }
+      // Verified in `assertConfig`
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+      const { useVerificationToken, getUserByEmail } = adapter!
 
-      const { useVerificationToken, getUserByEmail } = adapter
+      const token = query?.token
+      const identifier = query?.email
 
-      const token = req.query.token
-      const identifier = req.query.email
-
-      const invite = await useVerificationToken({
+      const invite = await useVerificationToken?.({
         identifier,
-        token: hashToken(token, req.options),
+        token: hashToken(token, options),
       })
 
       const invalidInvite = !invite || invite.expires.valueOf() < Date.now()
       if (invalidInvite) {
-        return res.redirect(`${baseUrl}${basePath}/error?error=Verification`)
+        return { redirect: `${url}/error?error=Verification`, cookies }
       }
 
       // If it is an existing user, use that, otherwise use a placeholder
@@ -205,30 +232,37 @@ export default async function callback(req, res) {
       // Check if user is allowed to sign in
       try {
         const signInCallbackResponse = await callbacks.signIn({
+          // @ts-expect-error
           user: profile,
+          // @ts-expect-error
           account,
+          // @ts-expect-error
           email: { email: identifier },
         })
         if (!signInCallbackResponse) {
-          return res.redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+          return { redirect: `${url}/error?error=AccessDenied`, cookies }
         } else if (typeof signInCallbackResponse === "string") {
-          return res.redirect(signInCallbackResponse)
+          return { redirect: signInCallbackResponse, cookies }
         }
       } catch (error) {
-        return res.redirect(
-          `${baseUrl}${basePath}/error?error=${encodeURIComponent(
-            error.message
-          )}`
-        )
+        return {
+          redirect: `${url}/error?error=${encodeURIComponent(
+            (error as Error).message
+          )}`,
+          cookies,
+        }
       }
 
       // Sign user in
-      const { user, session, isNewUser } = await callbackHandler(
-        sessionToken,
+      // @ts-expect-error
+      const { user, session, isNewUser } = await callbackHandler({
+        sessionToken: sessionStore.value,
+        // @ts-expect-error
         profile,
+        // @ts-expect-error
         account,
-        req.options
-      )
+        options,
+      })
 
       if (useJwtSession) {
         const defaultToken = {
@@ -240,99 +274,86 @@ export default async function callback(req, res) {
         const token = await callbacks.jwt({
           token: defaultToken,
           user,
+          // @ts-expect-error
           account,
           isNewUser,
         })
 
-        // Sign and encrypt token
-        const newEncodedJwt = await jwt.encode({ ...jwt, token })
+        // Encode token
+        const newToken = await jwt.encode({ ...jwt, token })
 
         // Set cookie expiry date
         const cookieExpires = new Date()
         cookieExpires.setTime(cookieExpires.getTime() + sessionMaxAge * 1000)
 
-        cookie.set(res, cookies.sessionToken.name, newEncodedJwt, {
-          expires: cookieExpires.toISOString(),
-          ...cookies.sessionToken.options,
+        const sessionCookies = sessionStore.chunk(newToken, {
+          expires: cookieExpires,
         })
+        cookies.push(...sessionCookies)
       } else {
         // Save Session Token in cookie
-        cookie.set(res, cookies.sessionToken.name, session.sessionToken, {
-          expires: session.expires,
-          ...cookies.sessionToken.options,
+        cookies.push({
+          name: options.cookies.sessionToken.name,
+          value: session.sessionToken,
+          options: {
+            ...options.cookies.sessionToken.options,
+            expires: session.expires,
+          },
         })
       }
 
+      // @ts-expect-error
       await events.signIn?.({ user, account, isNewUser })
 
       // Handle first logins on new accounts
       // e.g. option to send users to a new account landing page on initial login
       // Note that the callback URL is preserved, so the journey can still be resumed
       if (isNewUser && pages.newUser) {
-        return res.redirect(
-          `${pages.newUser}${
+        return {
+          redirect: `${pages.newUser}${
             pages.newUser.includes("?") ? "&" : "?"
-          }callbackUrl=${encodeURIComponent(callbackUrl)}`
-        )
+          }callbackUrl=${encodeURIComponent(callbackUrl)}`,
+          cookies,
+        }
       }
 
       // Callback URL is already verified at this point, so safe to use if specified
-      return res.redirect(callbackUrl || baseUrl)
+      return { redirect: callbackUrl, cookies }
     } catch (error) {
-      if (error.name === "CreateUserError") {
-        return res.redirect(
-          `${baseUrl}${basePath}/error?error=EmailCreateAccount`
-        )
+      if ((error as Error).name === "CreateUserError") {
+        return { redirect: `${url}/error?error=EmailCreateAccount`, cookies }
       }
-      logger.error("CALLBACK_EMAIL_ERROR", error)
-      return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
-    }
-  } else if (provider.type === "credentials" && req.method === "POST") {
-    if (!useJwtSession) {
-      logger.error(
-        "CALLBACK_CREDENTIALS_JWT_ERROR",
-        new Error(
-          "Signin in with credentials is only supported if JSON Web Tokens are enabled"
-        )
-      )
-      return res
-        .status(500)
-        .redirect(`${baseUrl}${basePath}/error?error=Configuration`)
+      logger.error("CALLBACK_EMAIL_ERROR", error as Error)
+      return { redirect: `${url}/error?error=Callback`, cookies }
     }
+  } else if (provider.type === "credentials" && method === "POST") {
+    const credentials = body
 
-    if (!provider.authorize) {
-      logger.error(
-        "CALLBACK_CREDENTIALS_HANDLER_ERROR",
-        new Error(
-          "Must define an authorize() handler to use credentials authentication provider"
-        )
-      )
-      return res
-        .status(500)
-        .redirect(`${baseUrl}${basePath}/error?error=Configuration`)
-    }
-
-    const credentials = req.body
-
-    let user
+    let user: User
     try {
-      user = await provider.authorize(credentials, {
-        ...req,
-        options: {},
-        cookies: {},
-      })
+      user = (await provider.authorize(credentials, {
+        query,
+        body,
+        headers,
+        method,
+      })) as User
       if (!user) {
-        return res.status(401).redirect(
-          `${baseUrl}${basePath}/error?${new URLSearchParams({
+        return {
+          status: 401,
+          redirect: `${url}/error?${new URLSearchParams({
             error: "CredentialsSignin",
             provider: provider.id,
-          })}`
-        )
+          })}`,
+          cookies,
+        }
       }
     } catch (error) {
-      return res.redirect(
-        `${baseUrl}${basePath}/error?error=${encodeURIComponent(error.message)}`
-      )
+      return {
+        redirect: `${url}/error?error=${encodeURIComponent(
+          (error as Error).message
+        )}`,
+        cookies,
+      }
     }
 
     /** @type {import("src").Account} */
@@ -345,20 +366,26 @@ export default async function callback(req, res) {
     try {
       const isAllowed = await callbacks.signIn({
         user,
+        // @ts-expect-error
         account,
         credentials,
       })
       if (!isAllowed) {
-        return res
-          .status(403)
-          .redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+        return {
+          status: 403,
+          redirect: `${url}/error?error=AccessDenied`,
+          cookies,
+        }
       } else if (typeof isAllowed === "string") {
-        return res.redirect(isAllowed)
+        return { redirect: isAllowed, cookies }
       }
     } catch (error) {
-      return res.redirect(
-        `${baseUrl}${basePath}/error?error=${encodeURIComponent(error.message)}`
-      )
+      return {
+        redirect: `${url}/error?error=${encodeURIComponent(
+          (error as Error).message
+        )}`,
+        cookies,
+      }
     }
 
     const defaultToken = {
@@ -371,27 +398,32 @@ export default async function callback(req, res) {
     const token = await callbacks.jwt({
       token: defaultToken,
       user,
+      // @ts-expect-error
       account,
       isNewUser: false,
     })
 
-    // Sign and encrypt token
-    const newEncodedJwt = await jwt.encode({ ...jwt, token })
+    // Encode token
+    const newToken = await jwt.encode({ ...jwt, token })
 
     // Set cookie expiry date
     const cookieExpires = new Date()
     cookieExpires.setTime(cookieExpires.getTime() + sessionMaxAge * 1000)
 
-    cookie.set(res, cookies.sessionToken.name, newEncodedJwt, {
-      expires: cookieExpires.toISOString(),
-      ...cookies.sessionToken.options,
+    const sessionCookies = sessionStore.chunk(newToken, {
+      expires: cookieExpires,
     })
 
+    cookies.push(...sessionCookies)
+
+    // @ts-expect-error
     await events.signIn?.({ user, account })
 
-    return res.redirect(callbackUrl || baseUrl)
+    return { redirect: callbackUrl, cookies }
+  }
+  return {
+    status: 500,
+    body: `Error: Callback for provider type ${provider.type} not supported`,
+    cookies,
   }
-  return res
-    .status(500)
-    .end(`Error: Callback for provider type ${provider.type} not supported`)
 }

src/core/routes/providers.ts

@@ -0,0 +1,30 @@
+import { OutgoingResponse } from ".."
+import { InternalProvider } from "../../lib/types"
+
+export interface PublicProvider {
+  id: string
+  name: string
+  type: string
+  signinUrl: string
+  callbackUrl: string
+}
+
+/**
+ * Return a JSON object with a list of all OAuth providers currently configured
+ * and their signin and callback URLs. This makes it possible to automatically
+ * generate buttons for all providers when rendering client side.
+ */
+export default function providers(
+  providers: InternalProvider[]
+): OutgoingResponse<Record<string, PublicProvider>> {
+  return {
+    headers: [{ key: "Content-Type", value: "application/json" }],
+    body: providers.reduce<Record<string, PublicProvider>>(
+      (acc, { id, name, type, signinUrl, callbackUrl }) => {
+        acc[id] = { id, name, type, signinUrl, callbackUrl }
+        return acc
+      },
+      {}
+    ),
+  }
+}

src/core/routes/session.ts

@@ -1,34 +1,56 @@
-import * as cookie from "../lib/cookie"
 import { fromDate } from "../lib/utils"
 
+import type { Adapter } from "../../adapters"
+import type { InternalOptions } from "../../lib/types"
+import type { OutgoingResponse } from ".."
+import type { Session } from "../.."
+import type { SessionStore } from "../lib/cookie"
+
+interface SessionParams {
+  options: InternalOptions
+  sessionStore: SessionStore
+}
+
 /**
  * Return a session object (without any private fields)
  * for Single Page App clients
- * @param {import("src/lib/types").NextAuthRequest} req
- * @param {import("src/lib/types").NextAuthResponse} res
  */
-export default async function session(req, res) {
-  const { cookies, adapter, jwt, events, callbacks, logger } = req.options
-  const useJwtSession = req.options.session.jwt
-  const sessionMaxAge = req.options.session.maxAge
-  const sessionToken = req.cookies[cookies.sessionToken.name]
 
-  if (!sessionToken) {
-    return res.json({})
+export default async function session(
+  params: SessionParams
+): Promise<OutgoingResponse<Session | {}>> {
+  const { options, sessionStore } = params
+  const {
+    adapter,
+    jwt,
+    events,
+    callbacks,
+    logger,
+    session: { strategy: sessionStrategy, maxAge: sessionMaxAge },
+  } = options
+
+  const response: OutgoingResponse<Session | {}> = {
+    body: {},
+    headers: [{ key: "Content-Type", value: "application/json" }],
+    cookies: [],
   }
 
-  let response = {}
-  if (useJwtSession) {
-    try {
-      // Decrypt and verify token
-      const decodedToken = await jwt.decode({ ...jwt, token: sessionToken })
+  const sessionToken = sessionStore.value
+
+  if (!sessionToken) return response
+
+  if (sessionStrategy === "jwt") {
+    try {
+      const decodedToken = await jwt.decode({
+        ...jwt,
+        token: sessionToken,
+      })
 
-      // Generate new session expiry date
       const newExpires = fromDate(sessionMaxAge)
 
       // By default, only exposes a limited subset of information to the client
       // as needed for presentation purposes (e.g. "you are logged in as...").
-      const defaultSession = {
+      const session = {
         user: {
           name: decodedToken?.name,
           email: decodedToken?.email,
@@ -37,37 +59,39 @@ export default async function session(req, res) {
         expires: newExpires.toISOString(),
       }
 
-      // Pass Session and JSON Web Token through to the session callback
+      // @ts-expect-error
       const token = await callbacks.jwt({ token: decodedToken })
-      const session = await callbacks.session({
-        session: defaultSession,
-        token,
-      })
+      // @ts-expect-error
+      const newSession = await callbacks.session({ session, token })
 
       // Return session payload as response
-      response = session
+      response.body = newSession
 
       // Refresh JWT expiry by re-signing it, with an updated expiry date
-      const newToken = await jwt.encode({ ...jwt, token })
+      const newToken = await jwt.encode({
+        ...jwt,
+        token,
+        maxAge: options.session.maxAge,
+      })
 
       // Set cookie, to also update expiry date on cookie
-      cookie.set(res, cookies.sessionToken.name, newToken, {
+      const sessionCookies = sessionStore.chunk(newToken, {
         expires: newExpires,
-        ...cookies.sessionToken.options,
       })
 
-      await events.session?.({ session, token })
+      response.cookies?.push(...sessionCookies)
+
+      await events.session?.({ session: newSession, token })
     } catch (error) {
       // If JWT not verifiable, make sure the cookie for it is removed and return empty object
-      logger.error("JWT_SESSION_ERROR", error)
-      cookie.set(res, cookies.sessionToken.name, "", {
-        ...cookies.sessionToken.options,
-        maxAge: 0,
-      })
+      logger.error("JWT_SESSION_ERROR", error as Error)
+
+      response.cookies?.push(...sessionStore.clean())
     }
   } else {
     try {
-      const { getSessionAndUser, deleteSession, updateSession } = adapter
+      const { getSessionAndUser, deleteSession, updateSession } =
+        adapter as Adapter
       let userAndSession = await getSessionAndUser(sessionToken)
 
       // If session has expired, clean up the database
@@ -82,7 +106,7 @@ export default async function session(req, res) {
       if (userAndSession) {
         const { user, session } = userAndSession
 
-        const sessionUpdateAge = req.options.session.updateAge
+        const sessionUpdateAge = options.session.updateAge
         // Calculate last updated date to throttle write updates to database
         // Formula: ({expiry date} - sessionMaxAge) + sessionUpdateAge
         //     e.g. ({expiry date} - 30 days) + 1 hour
@@ -99,6 +123,7 @@ export default async function session(req, res) {
         }
 
         // Pass Session through to the session callback
+        // @ts-expect-error
         const sessionPayload = await callbacks.session({
           // By default, only exposes a limited subset of information to the client
           // as needed for presentation purposes (e.g. "you are logged in as...").
@@ -114,27 +139,29 @@ export default async function session(req, res) {
         })
 
         // Return session payload as response
-        response = sessionPayload
+        response.body = sessionPayload
 
         // Set cookie again to update expiry
-        cookie.set(res, cookies.sessionToken.name, sessionToken, {
-          expires: newExpires,
-          ...cookies.sessionToken.options,
+        response.cookies?.push({
+          name: options.cookies.sessionToken.name,
+          value: sessionToken,
+          options: {
+            ...options.cookies.sessionToken.options,
+            expires: newExpires,
+          },
         })
 
+        // @ts-expect-error
         await events.session?.({ session: sessionPayload })
       } else if (sessionToken) {
-        // If sessionToken was found set but it's not valid for a session then
+        // If `sessionToken` was found set but it's not valid for a session then
         // remove the sessionToken cookie from browser.
-        cookie.set(res, cookies.sessionToken.name, "", {
-          ...cookies.sessionToken.options,
-          maxAge: 0,
-        })
+        response.cookies?.push(...sessionStore.clean())
       }
     } catch (error) {
-      logger.error("SESSION_ERROR", error)
+      logger.error("SESSION_ERROR", error as Error)
     }
   }
 
-  res.json(response)
+  return response
 }

src/core/routes/signin.ts

@@ -0,0 +1,92 @@
+import getAuthorizationUrl from "../lib/oauth/authorization-url"
+import emailSignin from "../lib/email/signin"
+import { IncomingRequest, OutgoingResponse } from ".."
+import { InternalOptions } from "../../lib/types"
+import { Account, User } from "../.."
+
+/** Handle requests to /api/auth/signin */
+export default async function signin(params: {
+  options: InternalOptions<"oauth" | "email">
+  query: IncomingRequest["query"]
+  body: IncomingRequest["body"]
+}): Promise<OutgoingResponse> {
+  const { options, query, body } = params
+  const { url, adapter, callbacks, logger, provider } = options
+
+  if (!provider.type) {
+    return {
+      status: 500,
+      // @ts-expect-error
+      text: `Error: Type not specified for ${provider.name}`,
+    }
+  }
+
+  if (provider.type === "oauth") {
+    try {
+      const response = await getAuthorizationUrl({ options, query })
+      return response
+    } catch (error) {
+      logger.error("SIGNIN_OAUTH_ERROR", { error: error as Error, provider })
+      return { redirect: `${url}/error?error=OAuthSignin` }
+    }
+  } else if (provider.type === "email") {
+    // Note: Technically the part of the email address local mailbox element
+    // (everything before the @ symbol) should be treated as 'case sensitive'
+    // according to RFC 2821, but in practice this causes more problems than
+    // it solves. We treat email addresses as all lower case. If anyone
+    // complains about this we can make strict RFC 2821 compliance an option.
+    const email = body?.email?.toLowerCase() ?? null
+
+    // Verified in `assertConfig`
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const { getUserByEmail } = adapter!
+    // If is an existing user return a user object (otherwise use placeholder)
+    const user: User = (email ? await getUserByEmail(email) : null) ?? {
+      email,
+      id: email,
+    }
+
+    const account: Account = {
+      providerAccountId: email,
+      userId: email,
+      type: "email",
+      provider: provider.id,
+    }
+
+    // Check if user is allowed to sign in
+    try {
+      // @ts-expect-error
+      const signInCallbackResponse = await callbacks.signIn({
+        user,
+        account,
+        email: { verificationRequest: true },
+      })
+      if (!signInCallbackResponse) {
+        return { redirect: `${url}/error?error=AccessDenied` }
+      } else if (typeof signInCallbackResponse === "string") {
+        return { redirect: signInCallbackResponse }
+      }
+    } catch (error) {
+      return {
+        redirect: `${url}/error?${new URLSearchParams({
+          error: error as string,
+        })}`,
+      }
+    }
+
+    try {
+      await emailSignin(email, options)
+    } catch (error) {
+      logger.error("SIGNIN_EMAIL_ERROR", error as Error)
+      return { redirect: `${url}/error?error=EmailSignin` }
+    }
+
+    const params = new URLSearchParams({
+      provider: provider.id,
+      type: provider.type,
+    })
+
+    return { redirect: `${url}/verify-request?${params}` }
+  }
+  return { redirect: `${url}/signin` }
+}

src/core/routes/signout.ts

@@ -0,0 +1,45 @@
+import type { Adapter } from "../../adapters"
+import type { InternalOptions } from "../../lib/types"
+import type { OutgoingResponse } from ".."
+import type { SessionStore } from "../lib/cookie"
+
+/** Handle requests to /api/auth/signout */
+export default async function signout(params: {
+  options: InternalOptions
+  sessionStore: SessionStore
+}): Promise<OutgoingResponse> {
+  const { options, sessionStore } = params
+  const { adapter, events, jwt, callbackUrl, logger, session } = options
+
+  const sessionToken = sessionStore?.value
+  if (!sessionToken) {
+    return { redirect: callbackUrl }
+  }
+
+  if (session.strategy === "jwt") {
+    // Dispatch signout event
+    try {
+      const decodedJwt = await jwt.decode({ ...jwt, token: sessionToken })
+      // @ts-expect-error
+      await events.signOut?.({ token: decodedJwt })
+    } catch (error) {
+      // Do nothing if decoding the JWT fails
+      logger.error("SIGNOUT_ERROR", error)
+    }
+  } else {
+    try {
+      const session = await (adapter as Adapter).deleteSession(sessionToken)
+      // Dispatch signout event
+      // @ts-expect-error
+      await events.signOut?.({ session })
+    } catch (error) {
+      // If error, log it but continue
+      logger.error("SIGNOUT_ERROR", error as Error)
+    }
+  }
+
+  // Remove Session Token
+  const sessionCookies = sessionStore.clean()
+
+  return { redirect: callbackUrl, cookies: sessionCookies }
+}

src/core/types.ts

@@ -1,8 +1,9 @@
-import { Adapter } from "../adapters"
-import { Provider, CredentialInput, ProviderType } from "../providers"
-import { TokenSetParameters } from "openid-client"
-import { JWT, JWTOptions } from "../jwt"
-import { LoggerInstance } from "../lib/logger"
+import type { Adapter } from "../adapters"
+import type { Provider, CredentialInput, ProviderType } from "../providers"
+import type { TokenSetParameters } from "openid-client"
+import type { JWT, JWTOptions } from "../jwt"
+import type { LoggerInstance } from "../lib/logger"
+import type { CookieSerializeOptions } from "cookie"
 
 export type Awaitable<T> = T | PromiseLike<T>
 
@@ -26,9 +27,10 @@ export interface NextAuthOptions {
   providers: Provider[]
   /**
    * A random string used to hash tokens, sign cookies and generate cryptographic keys.
-   * If not specified is uses a hash of all configuration options, including Client ID / Secrets for entropy.
-   * The default behavior is volatile, and **it is strongly recommended** you explicitly specify a value
-   * to avoid invalidating end user sessions when configuration changes are deployed.
+   * If not specified, it falls back to `jwt.secret` or `NEXTAUTH_SECRET` from environment vairables.
+   * Otherwise it will use a hash of all configuration options, including Client ID / Secrets for entropy.
+   *
+   * NOTE: The last behavior is extrmely volatile, and will throw an error in production.
    * * **Default value**: `string` (SHA hash of the "options" object)
    * * **Required**: No - **but strongly recommended**!
    *
@@ -201,7 +203,11 @@ export interface NextAuthOptions {
  * [Documentation](https://next-auth.js.org/configuration/options#theme) |
  * [Pages](https://next-auth.js.org/configuration/pages)
  */
-export type Theme = "auto" | "dark" | "light"
+export interface Theme {
+  colorScheme: "auto" | "dark" | "light"
+  logo?: string
+  brandColor?: string
+}
 
 /**
  * Different tokens returned by OAuth Providers.
@@ -274,7 +280,7 @@ export interface CallbacksOptions<
       verificationRequest?: boolean
     }
     /** If Credentials provider is used, it contains the user credentials */
-    credentials: Record<string, CredentialInput>
+    credentials?: Record<string, CredentialInput>
   }) => Awaitable<string | boolean>
   /**
    * This callback is called anytime the user is redirected to a callback URL (e.g. on signin or signout).
@@ -293,7 +299,7 @@ export interface CallbacksOptions<
    * This callback is called whenever a session is checked.
    * (Eg.: invoking the `/api/session` endpoint, using `useSession` or `getSession`)
    *
-   * ⚠ By default, only a subset (email, name, imgage)
+   * ⚠ By default, only a subset (email, name, image)
    * of the token is returned for increased security.
    *
    * If you want to make something available you added to the token through the `jwt` callback,
@@ -334,14 +340,7 @@ export interface CallbacksOptions<
 /** [Documentation](https://next-auth.js.org/configuration/options#cookies) */
 export interface CookieOption {
   name: string
-  options: {
-    httpOnly?: boolean
-    sameSite: true | "strict" | "lax" | "none"
-    path?: string
-    secure: boolean
-    maxAge?: number
-    domain?: string
-  }
+  options: CookieSerializeOptions
 }
 
 /** [Documentation](https://next-auth.js.org/configuration/options#cookies) */
@@ -350,6 +349,7 @@ export interface CookiesOptions {
   callbackUrl: CookieOption
   csrfToken: CookieOption
   pkceCodeVerifier: CookieOption
+  state: CookieOption
 }
 
 /**
@@ -424,9 +424,23 @@ export interface DefaultSession extends Record<string, unknown> {
  */
 export interface Session extends Record<string, unknown>, DefaultSession {}
 
+export type SessionStrategy = "jwt" | "database"
+
 /** [Documentation](https://next-auth.js.org/configuration/options#session) */
 export interface SessionOptions {
-  jwt: boolean
+  /**
+   * Choose how you want to save the user session.
+   * The default is `"jwt"`, an encrypted JWT (JWE) in the session cookie.
+   *
+   * If you use an `adapter` however, we default it to `"database"` instead.
+   * You can still force a JWT session by explicitly defining `"jwt"`.
+   *
+   * When using `"database"`, the session cookie will only contain a `sessionToken` value,
+   * which is used to look up the session in the database.
+   *
+   * [Documentation](https://next-auth.js.org/configuration/options#session) | [Adapter](https://next-auth.js.org/configuration/options#adapter) | [About JSON Web Tokens](https://next-auth.js.org/faq#json-web-tokens)
+   */
+  strategy: SessionStrategy
   /**
    * Relative time from now in seconds when to expire the session
    * @default 2592000 // 30 days
@@ -458,13 +472,3 @@ export interface DefaultUser {
  * [`profile` OAuth provider callback](https://next-auth.js.org/configuration/providers#using-a-custom-provider)
  */
 export interface User extends Record<string, unknown>, DefaultUser {}
-
-declare global {
-  // eslint-disable-next-line @typescript-eslint/no-namespace
-  namespace NodeJS {
-    interface ProcessEnv {
-      NEXTAUTH_URL?: string
-      VERCEL_URL?: string
-    }
-  }
-}

src/css/index.css

@@ -1,6 +1,6 @@
 :root {
   --border-width: 1px;
-  --border-radius: .3rem;
+  --border-radius: 0.3rem;
   --color-error: #c94b4b;
   --color-info: #157efb;
   --color-info-text: #fff;
@@ -43,7 +43,9 @@ body {
   background-color: var(--color-background);
   margin: 0;
   padding: 0;
-  font-family: -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
+  font-family: -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans,
+    sans-serif, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif,
+    "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
 }
 
 h1 {
@@ -54,7 +56,7 @@ h1 {
 }
 
 p {
-  color: var(--color-text)
+  color: var(--color-text);
 }
 
 form {
@@ -67,19 +69,19 @@ label {
   text-align: left;
   margin-bottom: 0.25rem;
   display: block;
-  color: #666;
+  color: var(--color-text);
 }
 
 input[type] {
   box-sizing: border-box;
   display: block;
   width: 100%;
-  padding: .5rem 1rem;
+  padding: 0.5rem 1rem;
   border: var(--border-width) solid var(--color-control-border);
   background: var(--color-background);
   font-size: 1rem;
   border-radius: var(--border-radius);
-  box-shadow: inset 0 .1rem .2rem rgba(0, 0, 0, .2);
+  box-shadow: inset 0 0.1rem 0.2rem rgba(0, 0, 0, 0.2);
   color: var(--color-text);
 
   &:focus {
@@ -107,15 +109,17 @@ a.button {
 
 button,
 a.button {
-  margin: 0 0 .75rem 0;
-  padding: .75rem 1rem;
+  margin: 0 0 0.75rem 0;
+  padding: 0.75rem 1rem;
   border: var(--border-width) solid var(--color-control-border);
   color: var(--color-primary);
   background-color: var(--color-background);
   font-size: 1rem;
   border-radius: var(--border-radius);
-  transition: all .1s ease-in-out;
-  box-shadow: 0 0.15rem 0.3rem rgba(0, 0, 0, .15), inset 0 .1rem .2rem var(--color-background), inset 0 -.1rem .1rem rgba(0, 0, 0, .05);
+  transition: all 0.1s ease-in-out;
+  box-shadow: 0 0.15rem 0.3rem rgba(0, 0, 0, 0.15),
+    inset 0 0.1rem 0.2rem var(--color-background),
+    inset 0 -0.1rem 0.1rem rgba(0, 0, 0, 0.05);
   font-weight: 500;
   position: relative;
 
@@ -124,7 +128,9 @@ a.button {
   }
 
   &:active {
-    box-shadow: 0 0.15rem 0.3rem rgba(0, 0, 0, .15), inset 0 .1rem .2rem var(--color-background), inset 0 -.1rem .1rem rgba(0, 0, 0, .1);
+    box-shadow: 0 0.15rem 0.3rem rgba(0, 0, 0, 0.15),
+      inset 0 0.1rem 0.2rem var(--color-background),
+      inset 0 -0.1rem 0.1rem rgba(0, 0, 0, 0.1);
     background-color: var(--color-button-active-background);
     border-color: var(--color-button-active-border);
     cursor: pointer;
@@ -146,13 +152,12 @@ a.site {
   position: absolute;
   width: 100%;
   height: 100%;
-  display: table;
+  display: grid;
+  place-items: center;
   margin: 0;
   padding: 0;
 
-  >div {
-    display: table-cell;
-    vertical-align: middle;
+  > div {
     text-align: center;
     padding: 0.5rem;
   }
@@ -163,7 +168,7 @@ a.site {
     display: inline-block;
     padding-left: 2rem;
     padding-right: 2rem;
-    margin-top: .5rem;
+    margin-top: 0.5rem;
   }
 
   .message {
@@ -172,7 +177,6 @@ a.site {
 }
 
 .signin {
-
   button,
   a.button,
   input[type="text"] {
@@ -192,9 +196,9 @@ a.site {
       content: "or";
       background: var(--color-background);
       color: #888;
-      padding: 0 .4rem;
+      padding: 0 0.4rem;
       position: relative;
-      top: -.6rem;
+      top: -0.6rem;
     }
   }
 
@@ -213,10 +217,9 @@ a.site {
     }
   }
 
-  >div,
+  > div,
   form {
     display: block;
-    margin: 0 auto 0.5rem auto;
 
     input[type] {
       margin-bottom: 0.5rem;
@@ -228,4 +231,32 @@ a.site {
 
     max-width: 300px;
   }
-}
+}
+.signout {
+  .message {
+    margin-bottom: 1.5rem;
+  }
+}
+
+.logo {
+  display: inline-block;
+  margin-top: 100px;
+  max-width: 300px;
+  max-height: 150px;
+}
+
+.card {
+  max-width: max-content;
+  border: 1px solid var(--color-control-border);
+  border-radius: 5px;
+  padding: 20px 50px;
+  margin: 50px auto;
+
+  .header {
+    color: var(--color-primary);
+  }
+}
+
+.section-header {
+  color: var(--brand-color, var(--color-text));
+}

src/index.ts

@@ -1,2 +1,6 @@
-export { default } from "./server"
-export * from "./server/types"
+export * from "./core/types"
+
+export type { IncomingRequest, OutgoingResponse } from "./core"
+
+export * from "./next"
+export { default } from "./next"

src/jwt/index.ts

@@ -1,217 +1,121 @@
-import crypto from "crypto"
-import jose from "jose"
-import logger from "../lib/logger"
-import { NextApiRequest } from "next"
-import type { JWT, JWTDecodeParams, JWTEncodeParams } from "./types"
+import { EncryptJWT, jwtDecrypt } from "jose"
+import hkdf from "@panva/hkdf"
+import { v4 as uuid } from "uuid"
+import { SessionStore } from "../core/lib/cookie"
+import type { NextApiRequest } from "next"
+import type { JWT, JWTDecodeParams, JWTEncodeParams, JWTOptions } from "./types"
+import type { LoggerInstance } from ".."
 
 export * from "./types"
 
-// Set default algorithm to use for auto-generated signing key
-const DEFAULT_SIGNATURE_ALGORITHM = "HS512"
-
-// Set default algorithm for auto-generated symmetric encryption key
-const DEFAULT_ENCRYPTION_ALGORITHM = "A256GCM"
-
-// Use encryption or not by default
-const DEFAULT_ENCRYPTION_ENABLED = false
-
 const DEFAULT_MAX_AGE = 30 * 24 * 60 * 60 // 30 days
 
-export async function encode({
-  token = {},
-  maxAge = DEFAULT_MAX_AGE,
-  secret,
-  signingKey,
-  signingOptions = {
-    expiresIn: `${maxAge}s`,
-  },
-  encryptionKey,
-  encryptionOptions = {
-    alg: "dir",
-    enc: DEFAULT_ENCRYPTION_ALGORITHM,
-    zip: "DEF",
-  },
-  encryption = DEFAULT_ENCRYPTION_ENABLED,
-}: JWTEncodeParams) {
-  // Signing Key
-  const _signingKey = signingKey
-    ? jose.JWK.asKey(JSON.parse(signingKey))
-    : getDerivedSigningKey(secret)
+const now = () => (Date.now() / 1000) | 0
 
-  // Sign token
-  const signedToken = jose.JWT.sign(token, _signingKey, signingOptions)
-
-  if (encryption) {
-    // Encryption Key
-    const _encryptionKey = encryptionKey
-      ? jose.JWK.asKey(JSON.parse(encryptionKey))
-      : getDerivedEncryptionKey(secret)
-
-    // Encrypt token
-    return jose.JWE.encrypt(signedToken, _encryptionKey, encryptionOptions)
-  }
-  return signedToken
+/** Issues a JWT. By default, the JWT is encrypted using "A256GCM". */
+export async function encode(params: JWTEncodeParams) {
+  const { token = {}, secret, maxAge = DEFAULT_MAX_AGE } = params
+  const encryptionSecret = await getDerivedEncryptionKey(secret)
+  return await new EncryptJWT(token)
+    .setProtectedHeader({ alg: "dir", enc: "A256GCM" })
+    .setIssuedAt()
+    .setExpirationTime(now() + maxAge)
+    .setJti(uuid())
+    .encrypt(encryptionSecret)
 }
 
-export async function decode({
-  secret,
-  token,
-  maxAge = DEFAULT_MAX_AGE,
-  signingKey,
-  verificationKey = signingKey, // Optional (defaults to encryptionKey)
-  verificationOptions = {
-    maxTokenAge: `${maxAge}s`,
-    algorithms: [DEFAULT_SIGNATURE_ALGORITHM],
-  },
-  encryptionKey,
-  decryptionKey = encryptionKey, // Optional (defaults to encryptionKey)
-  decryptionOptions = {
-    algorithms: [DEFAULT_ENCRYPTION_ALGORITHM],
-  },
-  encryption = DEFAULT_ENCRYPTION_ENABLED,
-}: JWTDecodeParams): Promise<JWT | null> {
+/** Decodes a NextAuth.js issued JWT. */
+export async function decode(params: JWTDecodeParams): Promise<JWT | null> {
+  const { token, secret } = params
   if (!token) return null
-
-  let tokenToVerify = token
-
-  if (encryption) {
-    // Encryption Key
-    const _encryptionKey = decryptionKey
-      ? jose.JWK.asKey(JSON.parse(decryptionKey))
-      : getDerivedEncryptionKey(secret)
-
-    // Decrypt token
-    const decryptedToken = jose.JWE.decrypt(
-      token,
-      _encryptionKey,
-      decryptionOptions
-    )
-    tokenToVerify = decryptedToken.toString("utf8")
-  }
-
-  // Signing Key
-  const _signingKey = verificationKey
-    ? jose.JWK.asKey(JSON.parse(verificationKey))
-    : getDerivedSigningKey(secret)
-
-  // Verify token
-  return jose.JWT.verify(
-    tokenToVerify,
-    _signingKey,
-    verificationOptions
-  ) as JWT | null
+  const encryptionSecret = await getDerivedEncryptionKey(secret)
+  const { payload } = await jwtDecrypt(token, encryptionSecret, {
+    clockTolerance: 15,
+  })
+  return payload
 }
 
-export type GetTokenParams<R extends boolean = false> = {
-  req: NextApiRequest
+export interface GetTokenParams<R extends boolean = false> {
+  /** The request containing the JWT either in the cookies or in the `Authorization` header. */
+  req: NextApiRequest | Pick<NextApiRequest, "cookies" | "headers">
+  /**
+   * Use secure prefix for cookie name, unless URL in `NEXTAUTH_URL` is http://
+   * or not set (e.g. development or test instance) case use unprefixed name
+   */
   secureCookie?: boolean
+  /** If the JWT is in the cookie, what name `getToken()` should look for. */
   cookieName?: string
+  /**
+   * `getToken()` will return the raw JWT if this is set to `true`
+   * @default false
+   */
   raw?: R
-  decode?: typeof decode
+  /**
+   * The same `secret` used in the `NextAuth` configuration.
+   * Defaults to the `NEXTAUTH_SECRET` environment variable.
+   */
   secret?: string
-} & Omit<JWTDecodeParams, "secret">
+  decode?: JWTOptions["decode"]
+  logger?: LoggerInstance | Console
+}
 
-/** [Documentation](https://next-auth.js.org/tutorials/securing-pages-and-api-routes#using-gettoken) */
+/**
+ * Takes a NextAuth.js request (`req`) and returns either the NextAuth.js issued JWT's payload,
+ * or the raw JWT string. We look for the JWT in the either the cookies, or the `Authorization` header.
+ * [Documentation](https://next-auth.js.org/tutorials/securing-pages-and-api-routes#using-gettoken)
+ */
 export async function getToken<R extends boolean = false>(
   params?: GetTokenParams<R>
 ): Promise<R extends true ? string : JWT | null> {
   const {
     req,
-    // Use secure prefix for cookie name, unless URL is NEXTAUTH_URL is http://
-    // or not set (e.g. development or test instance) case use unprefixed name
-    secureCookie = !(
-      !process.env.NEXTAUTH_URL ||
-      process.env.NEXTAUTH_URL.startsWith("http://")
-    ),
+    secureCookie = process.env.NEXTAUTH_URL?.startsWith("https://") ??
+      !!process.env.VERCEL,
     cookieName = secureCookie
       ? "__Secure-next-auth.session-token"
       : "next-auth.session-token",
-    raw = false,
+    raw,
     decode: _decode = decode,
+    logger = console,
+    secret = process.env.NEXTAUTH_SECRET,
   } = params ?? {}
+
   if (!req) throw new Error("Must pass `req` to JWT getToken()")
 
-  // Try to get token from cookie
-  let token = req.cookies[cookieName]
+  const sessionStore = new SessionStore(
+    { name: cookieName, options: { secure: secureCookie } },
+    { cookies: req.cookies, headers: req.headers },
+    logger
+  )
+
+  let token = sessionStore.value
 
-  // If cookie not found in cookie look for bearer token in authorization header.
-  // This allows clients that pass through tokens in headers rather than as
-  // cookies to use this helper function.
   if (!token && req.headers.authorization?.split(" ")[0] === "Bearer") {
     const urlEncodedToken = req.headers.authorization.split(" ")[1]
     token = decodeURIComponent(urlEncodedToken)
   }
 
-  if (raw) {
-    // @ts-expect-error
-    return token
-  }
+  // @ts-expect-error
+  if (!token) return null
+
+  // @ts-expect-error
+  if (raw) return token
 
   try {
     // @ts-expect-error
-    return await _decode({ token, ...params })
+    return await _decode({ token, secret })
   } catch {
     // @ts-expect-error
     return null
   }
 }
 
-// Generate warning (but only once at startup) when auto-generated keys are used
-let DERIVED_SIGNING_KEY_WARNING = false
-let DERIVED_ENCRYPTION_KEY_WARNING = false
-
-// Do the better hkdf of Node.js one added in `v15.0.0` and Third Party one
-function hkdf(secret, { byteLength, encryptionInfo, digest = "sha256" }) {
-  if (crypto.hkdfSync) {
-    return Buffer.from(
-      crypto.hkdfSync(
-        digest,
-        secret,
-        Buffer.alloc(0),
-        encryptionInfo,
-        byteLength
-      )
-    )
-  }
-  // eslint-disable-next-line @typescript-eslint/no-var-requires
-  return require("futoin-hkdf")(secret, byteLength, {
-    info: encryptionInfo,
-    hash: digest,
-  })
-}
-
-function getDerivedSigningKey(secret) {
-  if (!DERIVED_SIGNING_KEY_WARNING) {
-    logger.warn("JWT_AUTO_GENERATED_SIGNING_KEY")
-    DERIVED_SIGNING_KEY_WARNING = true
-  }
-
-  const buffer = hkdf(secret, {
-    byteLength: 64,
-    encryptionInfo: "NextAuth.js Generated Signing Key",
-  })
-  const key = jose.JWK.asKey(buffer, {
-    alg: DEFAULT_SIGNATURE_ALGORITHM,
-    use: "sig",
-    kid: "nextauth-auto-generated-signing-key",
-  })
-  return key
-}
-
-function getDerivedEncryptionKey(secret) {
-  if (!DERIVED_ENCRYPTION_KEY_WARNING) {
-    logger.warn("JWT_AUTO_GENERATED_ENCRYPTION_KEY")
-    DERIVED_ENCRYPTION_KEY_WARNING = true
-  }
-
-  const buffer = hkdf(secret, {
-    byteLength: 32,
-    encryptionInfo: "NextAuth.js Generated Encryption Key",
-  })
-  const key = jose.JWK.asKey(buffer, {
-    alg: DEFAULT_ENCRYPTION_ALGORITHM,
-    use: "enc",
-    kid: "nextauth-auto-generated-encryption-key",
-  })
-  return key
+async function getDerivedEncryptionKey(secret: string | Buffer) {
+  return await hkdf(
+    "sha256",
+    secret,
+    "",
+    "NextAuth.js Generated Encryption Key",
+    32
+  )
 }

src/jwt/types.ts

@@ -1,5 +1,4 @@
-import type { JWT as JoseJWT, JWE } from "jose"
-import { decode, encode } from "."
+import type { Awaitable } from ".."
 
 export interface DefaultJWT extends Record<string, unknown> {
   name?: string | null
@@ -16,36 +15,40 @@ export interface DefaultJWT extends Record<string, unknown> {
 export interface JWT extends Record<string, unknown>, DefaultJWT {}
 
 export interface JWTEncodeParams {
+  /** The JWT payload. */
   token?: JWT
-  maxAge?: number
+  /** The secret used to encode the NextAuth.js issued JWT. */
   secret: string | Buffer
-  signingKey?: string
-  signingOptions?: JoseJWT.SignOptions
-  encryptionKey?: string
-  encryptionOptions?: object
-  encryption?: boolean
+  /**
+   * The maximum age of the NextAuth.js issued JWT in seconds.
+   * @default 30 * 24 * 30 * 60 // 30 days
+   */
+  maxAge?: number
 }
 
 export interface JWTDecodeParams {
+  /** The NextAuth.js issued JWT to be decoded */
   token?: string
-  maxAge?: number
+  /** The secret used to decode the NextAuth.js issued JWT. */
   secret: string | Buffer
-  signingKey?: string
-  verificationKey?: string
-  verificationOptions?: JoseJWT.VerifyOptions<false>
-  encryptionKey?: string
-  decryptionKey?: string
-  decryptionOptions?: JWE.DecryptOptions<false>
-  encryption?: boolean
 }
 
 export interface JWTOptions {
+  /**
+   * The secret used to encode/decode the NextAuth.js issued JWT.
+   * @deprecated  Set the `NEXTAUTH_SECRET` environment vairable or
+   * use the top-level `secret` option instead
+   */
   secret: string
+  /**
+   * The maximum age of the NextAuth.js issued JWT in seconds.
+   * @default 30 * 24 * 30 * 60 // 30 days
+   */
   maxAge: number
-  encryption?: boolean
-  signingKey?: string
-  encryptionKey?: string
-  encode: typeof encode
-  decode: typeof decode
-  verificationOptions?: JoseJWT.VerifyOptions<false>
+  /** Override this method to control the NextAuth.js issued JWT encoding. */
+  encode: (params: JWTEncodeParams) => Awaitable<string>
+  /** Override this method to control the NextAuth.js issued JWT decoding. */
+  decode: (params: JWTDecodeParams) => Awaitable<JWT | null>
 }
+
+export type Secret = string | Buffer

src/lib/logger.ts

@@ -1,29 +1,33 @@
-import { UnknownError } from "../server/errors"
+import { UnknownError } from "../core/errors"
 
+// TODO: better typing
 /** Makes sure that error is always serializable */
-function formatError(o) {
+function formatError(o: unknown): unknown {
   if (o instanceof Error && !(o instanceof UnknownError)) {
     return { message: o.message, stack: o.stack, name: o.name }
   }
-  if (o?.error) {
-    o.error = formatError(o.error)
+  if (hasErrorProperty(o)) {
+    o.error = formatError(o.error) as Error
     o.message = o.message ?? o.error.message
   }
   return o
 }
 
+function hasErrorProperty(
+  x: unknown
+): x is { error: Error; [key: string]: unknown } {
+  return !!(x as any)?.error
+}
+
+export type WarningCode = "NEXTAUTH_URL" | "NO_SECRET" | "TWITTER_OAUTH_2_BETA"
+
 /**
  * Override any of the methods, and the rest will use the default logger.
  *
  * [Documentation](https://next-auth.js.org/configuration/options#logger)
  */
-export interface LoggerInstance {
-  warn: (
-    code:
-      | "JWT_AUTO_GENERATED_SIGNING_KEY"
-      | "JWT_AUTO_GENERATED_ENCRYPTION_KEY"
-      | "NEXTAUTH_URL"
-  ) => void
+export interface LoggerInstance extends Record<string, Function> {
+  warn: (code: WarningCode) => void
   error: (
     code: string,
     /**
@@ -38,7 +42,7 @@ export interface LoggerInstance {
 
 const _logger: LoggerInstance = {
   error(code, metadata) {
-    metadata = formatError(metadata)
+    metadata = formatError(metadata) as Error
     console.error(
       `[next-auth][error][${code}]`,
       `\nhttps://next-auth.js.org/errors#${code.toLowerCase()}`,
@@ -53,16 +57,21 @@ const _logger: LoggerInstance = {
     )
   },
   debug(code, metadata) {
-    if (!process?.env?._NEXTAUTH_DEBUG) return
     console.log(`[next-auth][debug][${code}]`, metadata)
   },
 }
 
 /**
- * Override the built-in logger.
+ * Override the built-in logger with user's implementation.
  * Any `undefined` level will use the default logger.
  */
-export function setLogger(newLogger: Partial<LoggerInstance> = {}) {
+export function setLogger(
+  newLogger: Partial<LoggerInstance> = {},
+  debug?: boolean
+) {
+  // Turn off debug logging if `debug` isn't set to `true`
+  if (!debug) _logger.debug = () => {}
+
   if (newLogger.error) _logger.error = newLogger.error
   if (newLogger.warn) _logger.warn = newLogger.warn
   if (newLogger.debug) _logger.debug = newLogger.debug
@@ -80,15 +89,15 @@ export function proxyLogger(
       return logger
     }
 
-    const clientLogger = {}
+    const clientLogger: Record<string, unknown> = {}
     for (const level in logger) {
-      clientLogger[level] = (code, metadata) => {
+      clientLogger[level] = (code: string, metadata: Error) => {
         _logger[level](code, metadata) // Logs to console
 
         if (level === "error") {
-          metadata = formatError(metadata)
+          metadata = formatError(metadata) as Error
         }
-        metadata.client = true
+        ;(metadata as any).client = true
         const url = `${basePath}/_log`
         const body = new URLSearchParams({ level, code, ...metadata })
         if (navigator.sendBeacon) {
@@ -97,7 +106,7 @@ export function proxyLogger(
         return fetch(url, { method: "POST", body, keepalive: true })
       }
     }
-    return clientLogger as LoggerInstance
+    return clientLogger as unknown as LoggerInstance
   } catch {
     return _logger
   }

src/lib/merge.ts

@@ -6,7 +6,7 @@ function isObject(item: any): boolean {
 }
 
 /** Deep merge two objects */
-export function merge(target: any, ...sources: any[]) {
+export function merge(target: any, ...sources: any[]): any {
   if (!sources.length) return target
   const source = sources.shift()
 

src/lib/parse-url.ts

@@ -1,29 +1,36 @@
-/**
- * Simple universal (client/server) function to split host and path.
- * We use this rather than a library because we need to use the same logic both
- * client and server side and we only need to parse out the host and path, while
- * supporting a default value, so a simple split is sufficent.
- * @todo Use `URL` instead of custom parsing. (Remember: `protocol` is not standard)
- */
-export default function parseUrl(url?: string) {
-  // Default values
-  const defaultHost = "http://localhost:3000"
-  const defaultPath = "/api/auth"
+export interface InternalUrl {
+  /** @default "http://localhost:3000" */
+  origin: string
+  /** @default "localhost:3000" */
+  host: string
+  /** @default "/api/auth" */
+  path: string
+  /** @default "http://localhost:3000/api/auth" */
+  base: string
+  /** @default "http://localhost:3000/api/auth" */
+  toString: () => string
+}
 
-  if (!url) {
-    url = `${defaultHost}${defaultPath}`
+/** Returns an `URL` like object to make requests/redirects from server-side */
+export default function parseUrl(url?: string): InternalUrl {
+  const defaultUrl = new URL("http://localhost:3000/api/auth")
+
+  if (url && !url.startsWith("http")) {
+    url = `https://${url}`
   }
 
-  // Default to HTTPS if no protocol explictly specified
-  const protocol = url.startsWith("http:") ? "http" : "https"
+  const _url = new URL(url ?? defaultUrl)
+  const path = (_url.pathname === "/" ? defaultUrl.pathname : _url.pathname)
+    // Remove trailing slash
+    .replace(/\/$/, "")
 
-  // Normalize URLs by stripping protocol and no trailing slash
-  url = url.replace(/^https?:\/\//, "").replace(/\/$/, "")
+  const base = `${_url.origin}${path}`
 
-  // Simple split based on first /
-  const [_host, ..._path] = url.split("/")
-  const baseUrl = _host ? `${protocol}://${_host}` : defaultHost
-  const basePath = _path.length > 0 ? `/${_path.join("/")}` : defaultPath
-
-  return { baseUrl, basePath }
+  return {
+    origin: _url.origin,
+    host: _url.host,
+    path,
+    base,
+    toString: () => base,
+  }
 }

src/lib/types.ts

@@ -11,35 +11,53 @@ import type {
   Awaitable,
 } from ".."
 
-import type { Provider } from "../providers"
+import type {
+  OAuthConfig,
+  EmailConfig,
+  CredentialsConfig,
+  ProviderType,
+} from "../providers"
 import type { JWTOptions } from "../jwt"
 import type { Adapter } from "../adapters"
+import { InternalUrl } from "./parse-url"
 
 // Below are types that are only supposed be used by next-auth internally
 
 /** @internal */
-export type InternalProvider = Provider & {
+export type InternalProvider<T extends ProviderType = any> = (T extends "oauth"
+  ? OAuthConfig<any>
+  : T extends "email"
+  ? EmailConfig
+  : T extends "credentials"
+  ? CredentialsConfig
+  : never) & {
   signinUrl: string
   callbackUrl: string
 }
 
+export type NextAuthAction =
+  | "providers"
+  | "session"
+  | "csrf"
+  | "signin"
+  | "signout"
+  | "callback"
+  | "verify-request"
+  | "error"
+  | "_log"
+
 /** @internal */
-export interface InternalOptions<
-  P extends InternalProvider = InternalProvider
-> {
+export interface InternalOptions<T extends ProviderType = any> {
   providers: InternalProvider[]
-  baseUrl: string
-  basePath: string
-  action:
-    | "providers"
-    | "session"
-    | "csrf"
-    | "signin"
-    | "signout"
-    | "callback"
-    | "verify-request"
-    | "error"
-  provider: P
+  /**
+   * Parsed from `NEXTAUTH_URL` or `x-forwarded-host` on Vercel.
+   * @default "http://localhost:3000/api/auth"
+   */
+  url: InternalUrl
+  action: NextAuthAction
+  provider: T extends string
+    ? InternalProvider<T>
+    : InternalProvider<T> | undefined
   csrfToken?: string
   csrfTokenVerified?: boolean
   secret: string

src/middleware.ts

@@ -0,0 +1,2 @@
+export { default } from "./next/middleware"
+export * from "./next/middleware"

src/next/index.ts

@@ -0,0 +1,118 @@
+import { NextAuthHandler } from "../core"
+import { setCookie, detectHost } from "./utils"
+
+import type {
+  GetServerSidePropsContext,
+  NextApiRequest,
+  NextApiResponse,
+} from "next"
+import type { NextAuthOptions, Session } from ".."
+import type {
+  NextAuthAction,
+  NextAuthRequest,
+  NextAuthResponse,
+} from "../lib/types"
+
+async function NextAuthNextHandler(
+  req: NextApiRequest,
+  res: NextApiResponse,
+  options: NextAuthOptions
+) {
+  const { nextauth, ...query } = req.query
+
+  options.secret =
+    options.secret ?? options.jwt?.secret ?? process.env.NEXTAUTH_SECRET
+
+  const handler = await NextAuthHandler({
+    req: {
+      host: detectHost(req.headers["x-forwarded-host"]),
+      body: req.body,
+      query,
+      cookies: req.cookies,
+      headers: req.headers,
+      method: req.method,
+      action: nextauth?.[0] as NextAuthAction,
+      providerId: nextauth?.[1],
+      error: (req.query.error as string | undefined) ?? nextauth?.[1],
+    },
+    options,
+  })
+
+  res.status(handler.status ?? 200)
+
+  handler.cookies?.forEach((cookie) => setCookie(res, cookie))
+
+  handler.headers?.forEach((h) => res.setHeader(h.key, h.value))
+
+  if (handler.redirect) {
+    // If the request expects a return URL, send it as JSON
+    // instead of doing an actual redirect.
+    if (req.body?.json !== "true") {
+      // Could chain. .end() when lowest target is Node 14
+      // https://github.com/nodejs/node/issues/33148
+      res.status(302).setHeader("Location", handler.redirect)
+      return res.end()
+    }
+    return res.json({ url: handler.redirect })
+  }
+
+  return res.send(handler.body)
+}
+
+function NextAuth(options: NextAuthOptions): any
+function NextAuth(
+  req: NextApiRequest,
+  res: NextApiResponse,
+  options: NextAuthOptions
+): any
+
+/** Tha main entry point to next-auth */
+function NextAuth(
+  ...args:
+    | [NextAuthOptions]
+    | [NextApiRequest, NextApiResponse, NextAuthOptions]
+) {
+  if (args.length === 1) {
+    return async (req: NextAuthRequest, res: NextAuthResponse) =>
+      await NextAuthNextHandler(req, res, args[0])
+  }
+
+  return NextAuthNextHandler(args[0], args[1], args[2])
+}
+
+export default NextAuth
+
+export async function getServerSession(
+  context:
+    | GetServerSidePropsContext
+    | { req: NextApiRequest; res: NextApiResponse },
+  options: NextAuthOptions
+): Promise<Session | null> {
+  const session = await NextAuthHandler<Session | {}>({
+    options,
+    req: {
+      host: detectHost(context.req.headers["x-forwarded-host"]),
+      action: "session",
+      method: "GET",
+      cookies: context.req.cookies,
+      headers: context.req.headers,
+    },
+  })
+
+  const { body, cookies } = session
+
+  cookies?.forEach((cookie) => setCookie(context.res, cookie))
+
+  if (body && Object.keys(body).length) return body as Session
+  return null
+}
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace NodeJS {
+    interface ProcessEnv {
+      NEXTAUTH_URL?: string
+      VERCEL?: "1"
+    }
+  }
+}

src/next/middleware.ts

@@ -0,0 +1,141 @@
+import type { NextMiddleware, NextFetchEvent } from "next/server"
+import type { Awaitable, NextAuthOptions } from ".."
+import type { JWT } from "../jwt"
+
+import { NextResponse, NextRequest } from "next/server"
+
+import { getToken } from "../jwt"
+import parseUrl from "../lib/parse-url"
+
+type AuthorizedCallback = (params: {
+  token: JWT | null
+  req: NextRequest
+}) => Awaitable<boolean>
+
+export interface NextAuthMiddlewareOptions {
+  /**
+   * Where to redirect the user in case of an error if they weren't logged in.
+   * Similar to `pages` in `NextAuth`.
+   *
+   * ---
+   * [Documentation](https://next-auth.js.org/configuration/pages)
+   */
+  pages?: NextAuthOptions["pages"]
+  callbacks?: {
+    /**
+     * Callback that receives the user's JWT payload
+     * and returns `true` to allow the user to continue.
+     *
+     * This is similar to the `signIn` callback in `NextAuthOptions`.
+     *
+     * If it returns `false`, the user is redirected to the sign-in page instead
+     *
+     * The default is to let the user continue if they have a valid JWT (basic authentication).
+     *
+     * How to restrict a page and all of it's subpages for admins-only:
+     * @example
+     *
+     * ```js
+     * // `pages/admin/_middleware.js`
+     * import { withAuth } from "next-auth/middleware"
+     *
+     * export default withAuth({
+     *   callbacks: {
+     *     authorized: ({ token }) => token?.user.isAdmin
+     *   }
+     * })
+     * ```
+     *
+     * ---
+     * [Documentation](https://next-auth.js.org/getting-started/nextjs/middleware#api) | [`signIn` callback](configuration/callbacks#sign-in-callback)
+     */
+    authorized?: AuthorizedCallback
+  }
+}
+
+async function handleMiddleware(
+  req: NextRequest,
+  options: NextAuthMiddlewareOptions | undefined,
+  onSuccess?: (token: JWT | null) => Promise<any>
+) {
+  const signInPage = options?.pages?.signIn ?? "/api/auth/signin"
+  const errorPage = options?.pages?.error ?? "/api/auth/error"
+  const basePath = parseUrl(process.env.NEXTAUTH_URL).path
+  // Avoid infinite redirect loop
+  if (
+    req.nextUrl.pathname.startsWith(basePath) ||
+    [signInPage, errorPage].includes(req.nextUrl.pathname)
+  ) {
+    return
+  }
+
+  if (!process.env.NEXTAUTH_SECRET) {
+    console.error(
+      `[next-auth][error][NO_SECRET]`,
+      `\nhttps://next-auth.js.org/errors#no_secret`
+    )
+
+    return {
+      redirect: NextResponse.redirect(`${errorPage}?error=Configuration`),
+    }
+  }
+
+  const token = await getToken({ req: req as any })
+
+  const isAuthorized =
+    (await options?.callbacks?.authorized?.({ req, token })) ?? !!token
+
+  // the user is authorized, let the middleware handle the rest
+  if (isAuthorized) return await onSuccess?.(token)
+
+  // the user is not logged in, re-direct to the sign-in page
+  return NextResponse.redirect(
+    `${signInPage}?${new URLSearchParams({ callbackUrl: req.url })}`
+  )
+}
+
+export type WithAuthArgs =
+  | [NextRequest]
+  | [NextRequest, NextFetchEvent]
+  | [NextRequest, NextAuthMiddlewareOptions]
+  | [NextMiddleware]
+  | [NextMiddleware, NextAuthMiddlewareOptions]
+  | [NextAuthMiddlewareOptions]
+
+/**
+ * Middleware that checks if the user is authenticated/authorized.
+ * If if they aren't, they will be redirected to the login page.
+ * Otherwise, continue.
+ *
+ * @example
+ *
+ * ```js
+ * // `pages/_middleware.js`
+ * export { default } from "next-auth/middleware"
+ * ```
+ *
+ * ---
+ * [Documentation](https://next-auth.js.org/getting-started/middleware)
+ */
+export function withAuth(...args: WithAuthArgs) {
+  if (args[0] instanceof NextRequest) {
+    // @ts-expect-error
+    return handleMiddleware(...args)
+  }
+
+  if (typeof args[0] === "function") {
+    const middleware = args[0]
+    const options = args[1] as NextAuthMiddlewareOptions | undefined
+    return async (...args: Parameters<NextMiddleware>) =>
+      await handleMiddleware(args[0], options, async (token) => {
+        ;(args[0] as any).nextauth = { token }
+        return await middleware(...args)
+      })
+  }
+
+  const options = args[0]
+  return async (...args: Parameters<NextMiddleware>) =>
+    await handleMiddleware(args[0], options)
+}
+
+export default withAuth

src/next/utils.ts

@@ -0,0 +1,23 @@
+import { serialize } from "cookie"
+import { Cookie } from "../core/lib/cookie"
+
+export function setCookie(res, cookie: Cookie) {
+  // Preserve any existing cookies that have already been set in the same session
+  let setCookieHeader = res.getHeader("Set-Cookie") ?? []
+  // If not an array (i.e. a string with a single cookie) convert it into an array
+  if (!Array.isArray(setCookieHeader)) {
+    setCookieHeader = [setCookieHeader]
+  }
+  const { name, value, options } = cookie
+  const cookieHeader = serialize(name, value, options)
+  setCookieHeader.push(cookieHeader)
+  res.setHeader("Set-Cookie", setCookieHeader)
+}
+
+/** Extract the host from the environment */
+export function detectHost(forwardedHost: any) {
+  // If we detect a Vercel environment, we can trust the host
+  if (process.env.VERCEL) return forwardedHost
+  // If `NEXTAUTH_URL` is `undefined` we fall back to "http://localhost:3000"
+  return process.env.NEXTAUTH_URL
+}

src/providers/42-school.ts

@@ -0,0 +1,179 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface UserData {
+  id: number
+  email: string
+  login: string
+  first_name: string
+  last_name: string
+  usual_full_name: null | string
+  usual_first_name: null | string
+  url: string
+  phone: "hidden" | string | null
+  displayname: string
+  image_url: string | null
+  "staff?": boolean
+  correction_point: number
+  pool_month: string | null
+  pool_year: string | null
+  location: string | null
+  wallet: number
+  anonymize_date: string
+  created_at: string
+  updated_at: string | null
+  alumni: boolean
+  "is_launched?": boolean
+}
+
+export interface CursusUser {
+  grade: string | null
+  level: number
+  skills: Array<{ id: number; name: string; level: number }>
+  blackholed_at: string | null
+  id: number
+  begin_at: string | null
+  end_at: string | null
+  cursus_id: number
+  has_coalition: boolean
+  created_at: string
+  updated_at: string | null
+  user: UserData
+  cursus: { id: number; created_at: string; name: string; slug: string }
+}
+
+export interface ProjectUser {
+  id: number
+  occurrence: number
+  final_mark: number | null
+  status: "in_progress" | "finished"
+  "validated?": boolean | null
+  current_team_id: number
+  project: {
+    id: number
+    name: string
+    slug: string
+    parent_id: number | null
+  }
+  cursus_ids: number[]
+  marked_at: string | null
+  marked: boolean
+  retriable_at: string | null
+  created_at: string
+  updated_at: string | null
+}
+
+export interface Achievement {
+  id: number
+  name: string
+  description: string
+  tier: "none" | "easy" | "medium" | "hard" | "challenge"
+  kind: "scolarity" | "project" | "pedagogy" | "scolarity"
+  visible: boolean
+  image: string | null
+  nbr_of_success: number | null
+  users_url: string
+}
+
+export interface LanguagesUser {
+  id: number
+  language_id: number
+  user_id: number
+  position: number
+  created_at: string
+}
+
+export interface TitlesUser {
+  id: number
+  user_id: number
+  title_id: number
+  selected: boolean
+  created_at: string
+  updated_at: string | null
+}
+
+export interface ExpertisesUser {
+  id: number
+  expertise_id: number
+  interested: boolean
+  value: number
+  contact_me: boolean
+  created_at: string
+  user_id: number
+}
+
+export interface Campus {
+  id: number
+  name: string
+  time_zone: string
+  language: {
+    id: number
+    name: string
+    identifier: string
+    created_at: string
+    updated_at: string | null
+  }
+  users_count: number
+  vogsphere_id: number
+  country: string
+  address: string
+  zip: string
+  city: string
+  website: string
+  facebook: string
+  twitter: string
+  active: boolean
+  email_extension: string
+  default_hidden_phone: boolean
+}
+
+export interface CampusUser {
+  id: number
+  user_id: number
+  campus_id: number
+  is_primary: boolean
+  created_at: string
+  updated_at: string | null
+}
+
+export interface FortyTwoProfile extends UserData {
+  groups: Array<{ id: string; name: string }>
+  cursus_users: CursusUser[]
+  projects_users: ProjectUser[]
+  languages_users: LanguagesUser[]
+  achievements: Achievement[]
+  titles: Array<{ id: string; name: string }>
+  titles_users: TitlesUser[]
+  partnerships: any[]
+  patroned: any[]
+  patroning: any[]
+  expertises_users: ExpertisesUser[]
+  roles: Array<{ id: string; name: string }>
+  campus: Campus[]
+  campus_users: CampusUser[]
+  user: any | null
+}
+
+export default function FortyTwo<
+  P extends Record<string, any> = FortyTwoProfile
+>(options: OAuthUserConfig<P>): OAuthConfig<P> {
+  return {
+    id: "42-school",
+    name: "42 School",
+    type: "oauth",
+    authorization: {
+      url: "https://api.intra.42.fr/oauth/authorize",
+      params: { scope: "public" },
+    },
+    token: "https://api.intra.42.fr/oauth/token",
+    userinfo: "https://api.intra.42.fr/v2/me",
+    profile(profile) {
+      return {
+        id: profile.id.toString(),
+        name: profile.usual_full_name,
+        email: profile.email,
+        image: profile.image_url,
+      }
+    },
+    options,
+  }
+}

src/providers/42.js

@@ -1,20 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function FortyTwo(options) {
-  return {
-    id: "42-school",
-    name: "42 School",
-    type: "oauth",
-    authorization: "https://api.intra.42.fr/oauth/authorize",
-    token: "https://api.intra.42.fr/oauth/token",
-    userinfo: "https://api.intra.42.fr/v2/me",
-    profile(profile) {
-      return {
-        id: profile.id,
-        name: profile.usual_full_name,
-        email: profile.email,
-        image: profile.image_url,
-      }
-    },
-    options,
-  }
-}

src/providers/apple.js

@@ -1,37 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function Apple(options) {
-  return {
-    id: "apple",
-    name: "Apple",
-    type: "oauth",
-    authorization: {
-      url: "https://appleid.apple.com/auth/authorize",
-      params: {
-        scope: "name email",
-        response_type: "code",
-        id_token: "",
-        response_mode: "form_post",
-      },
-    },
-    token: {
-      url: "https://appleid.apple.com/auth/token",
-      idToken: true,
-    },
-    jwks_endpoint: "https://appleid.apple.com/auth/keys",
-    profile(profile) {
-      // The name of the user will only be returned on first login
-      const name = profile.user
-        ? profile.user.name.firstName + " " + profile.user.name.lastName
-        : null
-
-      return {
-        id: profile.sub,
-        name,
-        email: profile.email,
-        image: null,
-      }
-    },
-    checks: ["none"], // REVIEW: Apple does not support state, as far as I know. Can we use "pkce" then?
-    options,
-  }
-}

src/providers/apple.ts

@@ -0,0 +1,122 @@
+import { OAuthConfig, OAuthUserConfig } from "."
+
+/**
+ * See more at:
+ * [Retrieve the User's Information from Apple ID Servers
+](https://developer.apple.com/documentation/sign_in_with_apple/sign_in_with_apple_rest_api/authenticating_users_with_sign_in_with_apple#3383773)
+ */
+export interface AppleProfile {
+  /**
+   * The issuer registered claim identifies the principal that issued the identity token.
+   * Since Apple generates the token, the value is `https://appleid.apple.com`.
+   */
+  iss: "https://appleid.apple.com"
+  /**
+   * The audience registered claim identifies the recipient for which the identity token is intended.
+   * Since the token is meant for your application, the value is the `client_id` from your developer account.
+   */
+  aud: string
+  /**
+   * The issued at registered claim indicates the time at which Apple issued the identity token,
+   * in terms of the number of seconds since Epoch, in UTC.
+   */
+  iat: number
+
+  /**
+   * The expiration time registered identifies the time on or after which the identity token expires,
+   * in terms of number of seconds since Epoch, in UTC.
+   * The value must be greater than the current date/time when verifying the token.
+   */
+  exp: number
+  /**
+   * The subject registered claim identifies the principal that's the subject of the identity token.
+   * Since this token is meant for your application, the value is the unique identifier for the user.
+   */
+  sub: string
+  /**
+   * A String value used to associate a client session and the identity token.
+   * This value mitigates replay attacks and is present only if passed during the authorization request.
+   */
+  nonce: string
+
+  /**
+   * A Boolean value that indicates whether the transaction is on a nonce-supported platform.
+   * If you sent a nonce in the authorization request but don't see the nonce claim in the identity token,
+   * check this claim to determine how to proceed.
+   * If this claim returns true, you should treat nonce as mandatory and fail the transaction;
+   * otherwise, you can proceed treating the nonce as options.
+   */
+  nonce_supported: boolean
+
+  /**
+   * A String value representing the user's email address.
+   * The email address is either the user's real email address or the proxy address,
+   * depending on their status private email relay service.
+   */
+  email: string
+
+  /**
+   * A String or Boolean value that indicates whether the service has verified the email.
+   * The value of this claim is always true, because the servers only return verified email addresses.
+   * The value can either be a String (`"true"`) or a Boolean (`true`).
+   */
+  email_verified: "true" | true
+
+  /**
+   * A String or Boolean value that indicates whether the email shared by the user is the proxy address.
+   * The value can either be a String (`"true"` or `"false"`) or a Boolean (`true` or `false`).
+   */
+  is_private_email: boolean | "true" | "false"
+
+  /**
+   * An Integer value that indicates whether the user appears to be a real person.
+   * Use the value of this claim to mitigate fraud. The possible values are: 0 (or Unsupported), 1 (or Unknown), 2 (or LikelyReal).
+   * For more information, see [`ASUserDetectionStatus`](https://developer.apple.com/documentation/authenticationservices/asuserdetectionstatus).
+   * This claim is present only on iOS 14 and later, macOS 11 and later, watchOS 7 and later, tvOS 14 and later;
+   * the claim isn't present or supported for web-based apps.
+   */
+  real_user_status: 0 | 1 | 2
+
+  /**
+   * A String value representing the transfer identifier used to migrate users to your team.
+   * This claim is present only during the 60-day transfer period after an you transfer an app.
+   * For more information, see [Bringing New Apps and Users into Your Team](https://developer.apple.com/documentation/sign_in_with_apple/bringing_new_apps_and_users_into_your_team).
+   */
+  transfer_sub: string
+  at_hash: string
+  auth_time: number
+}
+
+export default function Apple<P extends Record<string, any> = AppleProfile>(
+  options: Omit<OAuthUserConfig<P>, "clientSecret"> & {
+    /**
+     * Apple requires the client secret to be a JWT. You can generate one using the following script:
+     * https://bal.so/apple-gen-secret
+     * 
+     * Read more: [Creating the Client Secret
+](https://developer.apple.com/documentation/sign_in_with_apple/generate_and_validate_tokens#3262048)
+     */
+    clientSecret: string
+  }
+): OAuthConfig<P> {
+  return {
+    id: "apple",
+    name: "Apple",
+    type: "oauth",
+    wellKnown: "https://appleid.apple.com/.well-known/openid-configuration",
+    authorization: {
+      params: { scope: "name email", response_mode: "form_post" },
+    },
+    idToken: true,
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name,
+        email: profile.email,
+        image: null,
+      }
+    },
+    checks: ["pkce"],
+    options,
+  }
+}

src/providers/atlassian.ts

@@ -1,11 +1,21 @@
-/** @type {import(".").OAuthProvider} */
-export default function Atlassian(options) {
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+interface AtlassianProfile {
+  account_id: string
+  name: string
+  email: string
+  picture: string
+}
+
+export default function Atlassian<P extends AtlassianProfile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
   return {
     id: "atlassian",
     name: "Atlassian",
     type: "oauth",
     authorization: {
-      url: "https://auth.atlassian.com/oauth/authorize",
+      url: "https://auth.atlassian.com/authorize",
       params: {
         audience: "api.atlassian.com",
         prompt: "consent",

src/providers/auth0.ts

@@ -1,6 +1,15 @@
-import { OAuthConfig, OAuthUserConfig } from "./oauth"
+import type { OAuthConfig, OAuthUserConfig } from "."
 
-export default function Auth0(options: OAuthUserConfig): OAuthConfig {
+export interface Auth0Profile {
+  sub: string
+  nickname: string
+  email: string
+  picture: string
+}
+
+export default function Auth0<P extends Record<string, any> = Auth0Profile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
   return {
     id: "auth0",
     name: "Auth0",
@@ -9,7 +18,7 @@ export default function Auth0(options: OAuthUserConfig): OAuthConfig {
     authorization: { params: { scope: "openid email profile" } },
     checks: ["pkce", "state"],
     idToken: true,
-    profile(profile: any) {
+    profile(profile) {
       return {
         id: profile.sub,
         name: profile.nickname,

src/providers/authentik.ts

@@ -0,0 +1,44 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface AuthentikProfile {
+  iss: string,
+  sub: string,
+  aud: string,
+  exp: number,
+  iat: number,
+  auth_time: number,
+  acr: string,
+  c_hash: string,
+  nonce: string,
+  at_hash: string,
+  email: string,
+  email_verified: boolean,
+  name: string,
+  given_name: string,
+  family_name: string,
+  preferred_username: string,
+  nickname: string,
+  groups: string[]
+}
+
+export default function Authentik<
+  P extends Record<string, any> = AuthentikProfile
+>(options: OAuthUserConfig<P>): OAuthConfig<P> {
+  return {
+    id: "authentik",
+    name: "Authentik",
+    wellKnown: `${options.issuer}/.well-known/openid-configuration`,
+    type: "oauth",
+    authorization: { params: { scope: "openid email profile" } },
+    checks: ["pkce", "state"],
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name ?? profile.preferred_username,
+        email: profile.email,
+        image: profile.picture,
+      }
+    },
+    options,
+  }
+}

src/providers/azure-ad-b2c.js

@@ -1,44 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function AzureADB2C(options) {
-  const { tenantName, primaryUserFlow } = options
-
-  return {
-    id: "azure-ad-b2c",
-    name: "Azure Active Directory B2C",
-    type: "oauth",
-    authorization: {
-      url: `https://${tenantName}.b2clogin.com/${tenantName}.onmicrosoft.com/${primaryUserFlow}/oauth2/v2.0/authorize`,
-      params: {
-        response_type: "code id_token",
-        response_mode: "query",
-      },
-    },
-    token: {
-      url: `https://${tenantName}.b2clogin.com/${tenantName}.onmicrosoft.com/${primaryUserFlow}/oauth2/v2.0/token`,
-      idToken: true,
-    },
-    jwks_uri: `https://${tenantName}.b2clogin.com/${tenantName}.onmicrosoft.com/${primaryUserFlow}}/discovery/v2.0/keys`,
-    profile(profile) {
-      let name = ""
-
-      if (profile.name) {
-        // B2C "Display Name"
-        name = profile.name
-      } else if (profile.given_name && profile.family_name) {
-        // B2C "Given Name" & "Surname"
-        name = `${profile.given_name} ${profile.family_name}`
-      } else if (profile.given_name) {
-        // B2C "Given Name"
-        name = `${profile.given_name}`
-      }
-
-      return {
-        id: profile.oid,
-        name,
-        email: profile.emails[0],
-        image: null,
-      }
-    },
-    options,
-  }
-}

src/providers/azure-ad-b2c.ts

@@ -0,0 +1,46 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface AzureB2CProfile {
+  exp: number
+  nbf: number
+  ver: string
+  iss: string
+  sub: string
+  aud: string
+  iat: number
+  auth_time: number
+  oid: string
+  country: string
+  name: string
+  postalCode: string
+  emails: string[]
+  tfp: string
+}
+
+export default function AzureADB2C<
+  P extends Record<string, any> = AzureB2CProfile
+>(
+  options: OAuthUserConfig<P> & {
+    primaryUserFlow: string
+    tenantId: string
+  }
+): OAuthConfig<P> {
+  const { tenantId, primaryUserFlow } = options
+  return {
+    id: "azure-ad-b2c",
+    name: "Azure Active Directory B2C",
+    type: "oauth",
+    wellKnown: `https://${tenantId}.b2clogin.com/${tenantId}.onmicrosoft.com/${primaryUserFlow}/v2.0/.well-known/openid-configuration`,
+    idToken: true,
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name,
+        email: profile.emails[0],
+        // TODO: Find out how to retrieve the profile picture
+        image: null,
+      }
+    },
+    options,
+  }
+}

src/providers/azure-ad.js

@@ -1,22 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function AzureAD(options) {
-  const tenant = options.tenantId ?? "common"
-
-  return {
-    id: "azure-ad",
-    name: "Azure Active Directory",
-    type: "oauth",
-    authorization: `https://login.microsoftonline.com/${tenant}/oauth2/v2.0/authorize?response_mode=query`,
-    token: `https://login.microsoftonline.com/${tenant}/oauth2/v2.0/token`,
-    userinfo: "https://graph.microsoft.com/v1.0/me/",
-    profile(profile) {
-      return {
-        id: profile.id,
-        name: profile.displayName,
-        email: profile.userPrincipalName,
-        image: null,
-      }
-    },
-    options,
-  }
-}

src/providers/azure-ad.ts

@@ -0,0 +1,65 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface AzureADProfile {
+  sub: string
+  nicname: string
+  email: string
+  picture: string
+}
+
+export default function AzureAD<P extends Record<string, any> = AzureADProfile>(
+  options: OAuthUserConfig<P> & {
+    /**
+     * https://docs.microsoft.com/en-us/graph/api/profilephoto-get?view=graph-rest-1.0#examples
+     * @default 48
+     */
+    profilePhotoSize?: 48 | 64 | 96 | 120 | 240 | 360 | 432 | 504 | 648
+    /** @default "common" */
+    tenantId?: string
+  }
+): OAuthConfig<P> {
+  const tenant = options.tenantId ?? "common"
+  const profilePhotoSize = options.profilePhotoSize ?? 48
+
+  return {
+    id: "azure-ad",
+    name: "Azure Active Directory",
+    type: "oauth",
+    wellKnown: `https://login.microsoftonline.com/${tenant}/v2.0/.well-known/openid-configuration`,
+    authorization: {
+      params: {
+        scope: "openid profile email",
+      },
+    },
+    async profile(profile, tokens) {
+      // https://docs.microsoft.com/en-us/graph/api/profilephoto-get?view=graph-rest-1.0#examples
+      const profilePicture = await fetch(
+        `https://graph.microsoft.com/v1.0/me/photos/${profilePhotoSize}x${profilePhotoSize}/$value`,
+        {
+          headers: {
+            Authorization: `Bearer ${tokens.access_token}`,
+          },
+        }
+      )
+
+      // Confirm that profile photo was returned
+      if (profilePicture.ok) {
+        const pictureBuffer = await profilePicture.arrayBuffer()
+        const pictureBase64 = Buffer.from(pictureBuffer).toString("base64")
+        return {
+          id: profile.sub,
+          name: profile.name,
+          email: profile.email,
+          image: `data:image/jpeg;base64, ${pictureBase64}`,
+        }
+      } else {
+        return {
+          id: profile.sub,
+          name: profile.name,
+          email: profile.email,
+        }
+      }
+    },
+    options,
+  }
+}

src/providers/cognito.js

@@ -1,20 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function Cognito(options) {
-  return {
-    id: "cognito",
-    name: "Cognito",
-    type: "oauth",
-    authorization: `${options.issuer}oauth2/authorize?scope=openid+profile+email`,
-    token: `${options.issuer}oauth2/token`,
-    userinfo: `${options.issuer}oauth2/userInfo`,
-    profile(profile) {
-      return {
-        id: profile.sub,
-        name: profile.username,
-        email: profile.email,
-        image: null,
-      }
-    },
-    options,
-  }
-}

src/providers/cognito.ts

@@ -0,0 +1,29 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface CognitoProfile {
+  sub: string
+  name: string
+  email: string
+  picture: string
+}
+
+export default function Cognito<P extends Record<string, any> = CognitoProfile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
+  return {
+    id: "cognito",
+    name: "Cognito",
+    type: "oauth",
+    wellKnown: `${options.issuer}/.well-known/openid-configuration`,
+    idToken: true,
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name,
+        email: profile.email,
+        image: profile.picture,
+      }
+    },
+    options,
+  }
+}

src/providers/credentials.ts

@@ -1,6 +1,6 @@
-import { NextApiRequest } from "next"
-import { CommonProviderOptions } from "."
-import { User, Awaitable } from ".."
+import type { IncomingRequest } from "../core"
+import type { CommonProviderOptions } from "."
+import type { User, Awaitable } from ".."
 
 export interface CredentialInput {
   label?: string
@@ -10,13 +10,13 @@ export interface CredentialInput {
 }
 
 export interface CredentialsConfig<
-  C extends Record<string, CredentialInput> = {}
+  C extends Record<string, CredentialInput> = Record<string, CredentialInput>
 > extends CommonProviderOptions {
   type: "credentials"
   credentials: C
   authorize: (
-    credentials: Record<keyof C, string>,
-    req: NextApiRequest
+    credentials: Record<keyof C, string> | undefined,
+    req: Pick<IncomingRequest, "body" | "query" | "headers" | "method">
   ) => Awaitable<(Omit<User, "id"> | { id?: string }) | null>
 }
 

src/providers/dropbox.js

@@ -1,5 +1,5 @@
 /**
- * @param {import("../server").Provider} options
+ * @param {import("../core").Provider} options
  * @example
  *
  * ```js

src/providers/email.ts

@@ -1,8 +1,8 @@
 import { createTransport } from "nodemailer"
 
-import { CommonProviderOptions } from "."
-import { Options as SMTPConnectionOptions } from "nodemailer/lib/smtp-connection"
-import { Awaitable } from ".."
+import type { CommonProviderOptions } from "."
+import type { Options as SMTPConnectionOptions } from "nodemailer/lib/smtp-connection"
+import type { Awaitable } from ".."
 
 export interface EmailConfig extends CommonProviderOptions {
   type: "email"
@@ -72,7 +72,6 @@ export default function Email(options: EmailUserConfig): EmailConfig {
       provider: { server, from },
     }) {
       const { host } = new URL(url)
-      console.log(server)
       const transport = createTransport(server)
       await transport.sendMail({
         to: email,

src/providers/eveonline.js

@@ -1,20 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function EVEOnline(options) {
-  return {
-    id: "eveonline",
-    name: "EVE Online",
-    type: "oauth",
-    authorization: "https://login.eveonline.com/oauth/authorize",
-    token: "https://login.eveonline.com/oauth/token",
-    userinfo: "https://login.eveonline.com/oauth/verify",
-    profile(profile) {
-      return {
-        id: profile.CharacterID,
-        name: profile.CharacterName,
-        email: null,
-        image: `https://image.eveonline.com/Character/${profile.CharacterID}_128.jpg`,
-      }
-    },
-    options,
-  }
-}

src/providers/eveonline.ts

@@ -0,0 +1,38 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface EVEOnlineProfile {
+  CharacterID: number
+  CharacterName: string
+  ExpiresOn: string
+  Scopes: string
+  TokenType: string
+  CharacterOwnerHash: string
+  IntellectualProperty: string
+}
+
+export default function EVEOnline<
+  P extends Record<string, any> = EVEOnlineProfile
+>(options: OAuthUserConfig<P>): OAuthConfig<P> {
+  return {
+    id: "eveonline",
+    name: "EVE Online",
+    type: "oauth",
+    wellKnown:
+      "https://login.eveonline.com/.well-known/oauth-authorization-server",
+    authorization: {
+      params: {
+        scope: "publicData",
+      },
+    },
+    idToken: true,
+    profile(profile) {
+      return {
+        id: profile.CharacterID,
+        name: profile.CharacterName,
+        email: null,
+        image: `https://image.eveonline.com/Character/${profile.CharacterID}_128.jpg`,
+      }
+    },
+    options,
+  }
+}

src/providers/facebook.ts

@@ -1,7 +1,6 @@
-import { Profile } from ".."
-import { OAuthConfig, OAuthUserConfig } from "./oauth"
+import type { OAuthConfig, OAuthUserConfig } from "."
 
-export interface FacebookProfile extends Profile {
+export interface FacebookProfile {
   id: string
   picture: { data: { url: string } }
 }

src/providers/foursquare.js

@@ -1,3 +1,6 @@
+import { get } from 'https'
+import { once } from 'events'
+
 /** @type {import("src/providers").OAuthProvider} */
 /** @type {import(".").OAuthProvider} */
 export default function Foursquare(options) {
@@ -9,11 +12,29 @@ export default function Foursquare(options) {
     authorization: "https://foursquare.com/oauth2/authenticate",
     token: "https://foursquare.com/oauth2/access_token",
     userinfo: {
-      url: `https://api.foursquare.com/v2/users/self?v=${apiVersion}`,
-      request({ tokens, client }) {
-        return client.userinfo(undefined, {
-          params: { oauth_token: tokens.access_token },
-        })
+      async request({ tokens }) {
+        const url = new URL('https://api.foursquare.com/v2/users/self');
+        url.searchParams.append('v', apiVersion);
+        url.searchParams.append('oauth_token', tokens.access_token);
+
+        const req = get(url, { timeout: 3500 });
+        const [response] = await Promise.race([once(req, 'response'), once(req, 'timeout')])
+
+        // timeout reached
+        if (!response) {
+          req.destroy()
+          throw new Error('HTTP Request Timed Out')
+        }
+        if (response.statusCode !== 200) {
+          throw new Error('Expected 200 OK from the userinfo endpoint')
+        }
+
+        const parts = []
+        for await (const part of response) {
+          parts.push(part)
+        }
+
+        return JSON.parse(Buffer.concat(parts))
       },
     },
     profile({ response: { profile } }) {

src/providers/fusionauth.js

@@ -1,20 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function FusionAuth(options) {
-  return {
-    id: "fusionauth",
-    name: "FusionAuth",
-    type: "oauth",
-    authorization: `${options.issuer}oauth2/authorize`,
-    token: `${options.issuer}oauth2/token`,
-    userinfo: `${options.issuer}oauth2/userinfo`,
-    profile(profile) {
-      return {
-        id: profile.sub,
-        name: profile.name,
-        email: profile.email,
-        image: profile.picture,
-      }
-    },
-    options,
-  }
-}

src/providers/fusionauth.ts

@@ -0,0 +1,52 @@
+import { OAuthConfig, OAuthUserConfig } from "./oauth"
+
+/** This is the default openid signature returned from FusionAuth
+ * it can be customized using [lambda functions](https://fusionauth.io/docs/v1/tech/lambdas)
+ */
+export interface FusionAuthProfile {
+  aud: string
+  exp: number
+  iat: number
+  iss: string
+  sub: string
+  jti: string
+  authenticationType: string
+  email: string
+  email_verified: boolean
+  preferred_username: string
+  at_hash: string
+  c_hash: string
+  scope: string
+  sid: string
+}
+
+export default function FusionAuth<
+  P extends Record<string, any> = FusionAuthProfile
+>(
+  // tenantId only needed if there is more than one tenant configured on the server
+  options: OAuthUserConfig<P> & { tenantId?: string }
+): OAuthConfig<P> {
+  return {
+    id: "fusionauth",
+    name: "FusionAuth",
+    type: "oauth",
+    wellKnown: options?.tenantId
+      ? `${options.issuer}/.well-known/openid-configuration?tenantId=${options.tenantId}`
+      : `${options.issuer}/.well-known/openid-configuration`,
+    authorization: {
+      params: {
+        scope: "openid offline_access",
+        ...(options?.tenantId && { tenantId: options.tenantId }),
+      },
+    },
+    checks: ["pkce", "state"],
+    profile(profile) {
+      return {
+        id: profile.sub,
+        email: profile.email,
+        name: profile?.preferred_username,
+      }
+    },
+    options,
+  }
+}

src/providers/github.js

@@ -6,7 +6,31 @@ export default function GitHub(options) {
     type: "oauth",
     authorization: "https://github.com/login/oauth/authorize?scope=read:user+user:email",
     token: "https://github.com/login/oauth/access_token",
-    userinfo: "https://api.github.com/user",
+    userinfo: {
+      url: "https://api.github.com/user",
+      async request({ client, tokens }) {
+        // Get base profile
+        const profile = await client.userinfo(tokens)
+
+        // If user has email hidden, get their primary email from the GitHub API
+        if (!profile.email) {
+          const emails = await (
+            await fetch("https://api.github.com/user/emails", {
+              headers: { Authorization: `token ${tokens.access_token}` },
+            })
+          ).json()
+
+          if (emails?.length > 0) {
+            // Get primary email
+            profile.email = emails.find(email => email.primary)?.email;
+            // And if for some reason it doesn't exist, just use the first
+            if (!profile.email) profile.email = emails[0].email;
+          }
+        }
+
+        return profile
+      },
+    },
     profile(profile) {
       return {
         id: profile.id.toString(),

src/providers/google.ts

@@ -1,9 +1,21 @@
-import { Profile } from ".."
-import { OAuthConfig, OAuthUserConfig } from "./oauth"
+import type { OAuthConfig, OAuthUserConfig } from "."
 
-export interface GoogleProfile extends Profile {
-  sub: string
+export interface GoogleProfile {
+  aud: string
+  azp: string
+  email: string
+  email_verified: boolean
+  exp: number
+  family_name: string
+  given_name: string
+  hd: string
+  iat: number
+  iss: string
+  jti: string
+  name: string
+  nbf: number
   picture: string
+  sub: string
 }
 
 export default function Google<P extends Record<string, any> = GoogleProfile>(
@@ -17,7 +29,7 @@ export default function Google<P extends Record<string, any> = GoogleProfile>(
     authorization: { params: { scope: "openid email profile" } },
     idToken: true,
     checks: ["pkce", "state"],
-    profile(profile: P) {
+    profile(profile) {
       return {
         id: profile.sub,
         name: profile.name,

src/providers/index.ts

@@ -1,8 +1,8 @@
-import { OAuthConfig, OAuthProvider, OAuthProviderType } from "./oauth"
+import type { OAuthConfig, OAuthProvider, OAuthProviderType } from "./oauth"
 
-import { EmailConfig, EmailProvider, EmailProviderType } from "./email"
+import type { EmailConfig, EmailProvider, EmailProviderType } from "./email"
 
-import {
+import type {
   CredentialsConfig,
   CredentialsProvider,
   CredentialsProviderType,
@@ -21,7 +21,7 @@ export interface CommonProviderOptions {
   options?: Record<string, unknown>
 }
 
-export type Provider = OAuthConfig | EmailConfig | CredentialsConfig
+export type Provider = OAuthConfig<any> | EmailConfig | CredentialsConfig
 
 export type BuiltInProviders = Record<OAuthProviderType, OAuthProvider> &
   Record<CredentialsProviderType, CredentialsProvider> &

src/providers/kakao.js

@@ -1,20 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function Kakao(options) {
-  return {
-    id: "kakao",
-    name: "Kakao",
-    type: "oauth",
-    authorization: "https://kauth.kakao.com/oauth/authorize",
-    token: "https://kauth.kakao.com/oauth/token",
-    userinfo: "https://kapi.kakao.com/v2/user/me",
-    profile(profile) {
-      return {
-        id: profile.id,
-        name: profile.kakao_account?.profile.nickname,
-        email: profile.kakao_account?.email,
-        image: profile.kakao_account?.profile.profile_image_url,
-      }
-    },
-    options,
-  }
-}

src/providers/kakao.ts

@@ -0,0 +1,92 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export type DateTime = string
+export type Gender = "female" | "male"
+export type AgeRange =
+  | "1-9"
+  | "10-14"
+  | "15-19"
+  | "20-29"
+  | "30-39"
+  | "40-49"
+  | "50-59"
+  | "60-69"
+  | "70-79"
+  | "80-89"
+  | "90-"
+
+/**
+ * https://developers.kakao.com/docs/latest/ko/kakaologin/rest-api#req-user-info
+ * type from : https://gist.github.com/ziponia/cdce1ebd88f979b2a6f3f53416b56a77
+ */
+export interface KakaoProfile {
+  id: number
+  has_signed_up?: boolean
+  connected_at?: DateTime
+  synched_at?: DateTime
+  properties?: {
+    id?: string
+    status?: string
+    registered_at?: DateTime
+    msg_blocked?: boolean
+    nickname?: string
+    profile_image?: string
+    thumbnail_image?: string
+  }
+  kakao_account?: {
+    profile_needs_agreement?: boolean
+    profile_nickname_needs_agreement?: boolean
+    profile_image_needs_agreement?: boolean
+    profile?: {
+      nickname?: string
+      thumbnail_image_url?: string
+      profile_image_url?: string
+      is_default_image?: boolean
+    }
+    name_needs_agreement?: boolean
+    name?: string
+    email_needs_agreement?: boolean
+    is_email_valid?: boolean
+    is_email_verified?: boolean
+    email?: string
+    age_range_needs_agreement?: boolean
+    age_range?: AgeRange
+    birthyear_needs_agreement?: boolean
+    birthyear?: string
+    birthday_needs_agreement?: boolean
+    birthday?: string
+    birthday_type?: string
+    gender_needs_agreement?: boolean
+    gender?: Gender
+    phone_number_needs_agreement?: boolean
+    phone_number?: string
+    ci_needs_agreement?: boolean
+    ci?: string
+    ci_authenticated_at?: DateTime
+  }
+}
+
+export default function Kakao<P extends Record<string, any> = KakaoProfile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
+  return {
+    id: "kakao",
+    name: "Kakao",
+    type: "oauth",
+    authorization: "https://kauth.kakao.com/oauth/authorize?scope",
+    token: "https://kauth.kakao.com/oauth/token",
+    userinfo: "https://kapi.kakao.com/v2/user/me",
+    client: {
+      token_endpoint_auth_method: "client_secret_post",
+    },
+    profile(profile) {
+      return {
+        id: profile.id,
+        name: profile.kakao_account?.profile.nickname,
+        email: profile.kakao_account?.email,
+        image: profile.kakao_account?.profile.profile_image_url,
+      }
+    },
+    options,
+  }
+}

src/providers/keycloak.js

@@ -1,21 +0,0 @@
-/** @type {import("src/providers").OAuthProvider} */
-export default function Keycloak(options) {
-  return {
-    id: "keycloak",
-    name: "Keycloak",
-    wellKnown: `${options.issuer}/.well-known/openid-configuration`,
-    type: "oauth",
-    authorization: { params: { scope: "openid email profile" } },
-    checks: ["pkce", "state"],
-    idToken: true,
-    profile(profile) {
-      return {
-        id: profile.sub,
-        name: profile.name ?? profile.preferred_username,
-        email: profile.email,
-        image: null,
-      }
-    },
-    options,
-  }
-}

src/providers/keycloak.ts

@@ -0,0 +1,48 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface KeycloakProfile {
+  exp: number
+  iat: number
+  auth_time: number
+  jti: string
+  iss: string
+  aud: string
+  sub: string
+  typ: string
+  azp: string
+  session_state: string
+  at_hash: string
+  acr: string
+  sid: string
+  email_verified: boolean
+  name: string
+  preferred_username: string
+  given_name: string
+  family_name: string
+  email: string
+  picture: string
+  user: any
+}
+
+export default function Keycloak<
+  P extends Record<string, any> = KeycloakProfile
+>(options: OAuthUserConfig<P>): OAuthConfig<P> {
+  return {
+    id: "keycloak",
+    name: "Keycloak",
+    wellKnown: `${options.issuer}/.well-known/openid-configuration`,
+    type: "oauth",
+    authorization: { params: { scope: "openid email profile" } },
+    checks: ["pkce", "state"],
+    idToken: true,
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name ?? profile.preferred_username,
+        email: profile.email,
+        image: profile.picture,
+      }
+    },
+    options,
+  }
+}

src/providers/line.js

@@ -1,21 +0,0 @@
-/** @type {import(".").OAuthProvider} */
-export default function LINE(options) {
-  return {
-    id: "line",
-    name: "LINE",
-    type: "oauth",
-    authorization:
-      "https://access.line.me/oauth2/v2.1/authorize?scope=openid+profile",
-    token: "https://api.line.me/oauth2/v2.1/token",
-    userinfo: "https://api.line.me/v2/profile",
-    profile(profile) {
-      return {
-        id: profile.userId,
-        name: profile.displayName,
-        email: null,
-        image: profile.pictureUrl,
-      }
-    },
-    options,
-  }
-}

src/providers/line.ts

@@ -0,0 +1,38 @@
+import type { OAuthConfig, OAuthUserConfig } from "."
+
+export interface LineProfile {
+  iss: string
+  sub: string
+  aud: string
+  exp: number
+  iat: number
+  amr: string[]
+  name: string
+  picture: string
+  user: any
+}
+
+export default function LINE<P extends Record<string, any> = LineProfile>(
+  options: OAuthUserConfig<P>
+): OAuthConfig<P> {
+  return {
+    id: "line",
+    name: "LINE",
+    type: "oauth",
+    authorization: { params: { scope: "openid profile" } },
+    idToken: true,
+    wellKnown: "https://access.line.me/.well-known/openid-configuration",
+    profile(profile) {
+      return {
+        id: profile.sub,
+        name: profile.name,
+        email: profile.email,
+        image: profile.picture,
+      }
+    },
+    client: {
+      id_token_signed_response_alg: "HS256",
+    },
+    options,
+  }
+}