Merge branch 'main' into canary

fixes #1206

.env.example

@@ -1,3 +1,5 @@
+# Rename file to .env and populate values
+# to be able to run tests
 NEXTAUTH_URL=http://localhost:3000
 NEXTAUTH_TWITTER_ID=
 NEXTAUTH_TWITTER_SECRET=

.env.local.example

@@ -0,0 +1,6 @@
+# Rename file to .env.local and populate values
+# to be able to run the dev app
+NEXTAUTH_URL=http://localhost:3000
+SECRET=
+GITHUB_ID=
+GITHUB_SECRET=

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1 @@
+blank_issues_enabled: false

.github/ISSUE_TEMPLATE/question.md

@@ -4,6 +4,7 @@ about: Ask a question about NextAuth.js or for help using it
 labels: question
 assignees: ''
 ---
+<!-- NOTE: Questions will be converted to Discussions. You can find them at https://github.com/nextauthjs/next-auth/discussions! -->
 
 **Your question**
 <!-- A clear and concise question. -->

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,41 @@
+<!--
+Thanks for your interest in the project. Bugs filed and PRs submitted are appreciated!
+
+Please make sure that you are familiar with and follow the Code of Conduct for
+this project (found in the CODE_OF_CONDUCT.md file).
+
+Also, please make sure you're familiar with and follow the instructions in the
+contributing guidelines (found in the CONTRIBUTING.md file).
+
+If you're new to contributing to open source projects, you might find this free
+video course helpful: https://kcd.im/pull-request
+
+Please fill out the information below to expedite the review and (hopefully)
+merge of your pull request!
+-->
+
+<!-- What changes are being made? (What feature/bug is being fixed here?) -->
+
+**What**:
+
+<!-- Why are these changes necessary? -->
+
+**Why**:
+
+<!-- How were these changes implemented? -->
+
+**How**:
+
+<!-- Have you done all of these things?  -->
+
+**Checklist**:
+
+<!-- add "N/A" to the end of each line that's irrelevant to your changes -->
+<!-- to check an item, place an "x" in the box like so: "- [x] Documentation" -->
+
+- [ ] Documentation
+- [ ] Tests
+- [ ] Ready to be merged
+      <!-- In your opinion, is this ready to be merged as soon as it's reviewed? -->
+
+<!-- feel free to add additional comments -->

.github/labeler.yml

@@ -0,0 +1,21 @@
+test:
+  - test/**/*
+
+documentation:
+  - www/**/*
+  - ./**/*.md
+
+providers:
+  - src/providers/**/*
+  - www/docs/configuration/providers.md
+  - test/integration/**/*
+
+adapters:
+  - src/adapters/**/*
+  - www/docs/schemas/adapters.md
+
+databases:
+  - www/docs/schemas/*.md
+  - test/docker/databases/**/*
+  - www/docs/configuration/databases.md
+  - test/fixtures/**/*

.github/workflows/integration.yml

@@ -2,9 +2,9 @@ name: Integration Test
 
 on:
   push:
-    branches: [ main ]
+    branches: [ main, canary ]
   pull_request:
-    branches: [ main ]
+    branches: [ main, canary ]
 
 jobs:
   test:

.github/workflows/labeler.yml

@@ -0,0 +1,12 @@
+name: "Pull Request Labeler"
+on:
+- pull_request_target
+
+jobs:
+  triage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/labeler@main
+      with:
+        repo-token: "${{ secrets.GITHUB_TOKEN }}"
+        sync-labels: true

.github/workflows/npm-publish.yml

@@ -1,34 +0,0 @@
-# Publishes module to registry when a new release is created.
-# The following secrets need to be configured for this workflow:
-# * NPM_TOKEN - Auth token from npmjs.com
-name: Publish to NPM
-
-on:
-  release:
-    types: [created]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
-        with:
-          node-version: 12
-      - run: npm ci
-      - run: npm run build
-      - run: npm run lint
-
-  publish-npm:
-    needs: build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
-        with:
-          node-version: 12
-          registry-url: https://registry.npmjs.org/
-      - run: npm ci
-      - run: npm publish
-        env:
-          NODE_AUTH_TOKEN: ${{secrets.NPM_TOKEN}}

.github/workflows/release.yml

@@ -0,0 +1,30 @@
+name: Release
+on:
+  push:
+    branches:
+      - main
+      - canary
+jobs:
+  release:
+    name: Release
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Setup Node.js
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12
+      - name: Install dependencies
+        run: npm ci
+      - name: Lint  
+        run: npm run lint
+      - name: Build
+        run: npm run build
+      - name: Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: npx semantic-release

.releaserc.json

@@ -0,0 +1,39 @@
+{
+  "branches": [
+    "main",
+    { "name": "canary", "prerelease": true }
+  ],
+  "plugins": [
+    ["@semantic-release/commit-analyzer", {
+      "preset": "conventionalcommits",
+      "releaseRules": [
+        { "breaking": true, "release": "major" },
+        { "revert": true, "release": "patch" },
+        { "type": "feat", "release": "minor" },
+        { "type": "fix", "release": "patch" },
+        { "type": "perf", "release": "patch" },
+        { "type": "docs", "release": "patch" }
+      ]
+    }],
+    ["@semantic-release/release-notes-generator", {
+      "preset": "conventionalcommits",
+      "presetConfig": {
+        "types": [
+          { "type": "feat", "section": "Features", "hidden": false },
+          { "type": "fix", "section": "Bug Fixes", "hidden": false },
+          { "type": "perf", "section": "Performance Improvements", "hidden": false },
+          { "type": "revert", "section": "Reverts", "hidden": false },
+          { "type": "docs", "section": "Documentation", "hidden": false },
+          { "type": "style", "section": "Styles", "hidden": false },
+          { "type": "chore", "section": "Miscellaneous Chores", "hidden": false },
+          { "type": "refactor", "section": "Code Refactoring", "hidden": false },
+          { "type": "test", "section": "Tests", "hidden": false },
+          { "type": "build", "section": "Build System", "hidden": false },
+          { "type": "ci", "section": "Continuous Integration", "hidden": false }
+        ]
+      }
+    }],
+    "@semantic-release/github",
+    "@semantic-release/npm"
+  ]
+}

CHANGELOG.md

@@ -0,0 +1,5 @@
+# CHANGELOG
+
+The changelog is automatically updated using
+[semantic-release](https://github.com/semantic-release/semantic-release). You
+can see it on the [releases page](../../releases).

CONTRIBUTING.md

@@ -8,115 +8,71 @@ Please see the [Code of Conduct](CODE_OF_CONDUCT.md) and follow any templates co
 
 Please raise any significant new functionality or breaking change an issue for discussion before raising a Pull Request for it.
 
-## Pull Requests
+## For contributors
 
-* The latest changes are always in `main` 
-* Pull Requests should be raised for larger changes
-* Pull Requests do not need approval before merging for those with contributor access (it's just helpful to have them to track changes)
+Anyone can be a contributor. Either you found a typo, or you have an awesome feature request you could implement, we encourage you to create a Pull Request.
+### Pull Requests
+
+* The latest changes are always in `canary`, so please make your Pull Request against that branch.
+* Pull Requests should be raised for any change
+* Pull Requests need approval of a [core contributor](https://next-auth.js.org/contributors#core-team) before merging
 * Rebasing in Pull Requests is preferred to keep a clean commit history (see below)
-* Running `npm run lint:fix` before committing can make resolving conflicts easier, but is not required
-* Merge commits (and pushing merge commits to `main`) are disabled in this repo, but commits in PR can be squashed so this is not a blocker
-* Pushing directly to main should ideally be reserved for minor updates (e.g. correcting typos) or small single-commit fixes
+* Run `npm run lint:fix` before committing to make resolving conflicts easier (VSCode users, check out [this extension](https://marketplace.visualstudio.com/items?itemName=chenxsan.vscode-standardjs) to fix lint issues in development)
+* We encourage you to test your changes, and if you have the opportunity, please make those tests part of the Pull Request
+* If you add new functionality, please provide the corresponding documentation as well and make it part of the Pull Request
 
-## Rebasing
+### Setting up local environment
 
-*If you don't rebase and end up with merge commits in a PR then it's not a blocker, we can always squash the commits when merging!*
-
-If you create a branch and there are conflicting updates in the `main` branch, you can resolve them by rebasing from a check out of your branch:
-
-    git fetch
-    git rebase origin/main
-
-If there are any conflicts, you can resolve them and stage the files, then run:
-
-    git rebase --continue
-
-*If there are a lot of changes you may be prompted to step more than once.*
-
-When the rebase is complete (i.e. there are no more conflicts) you should push your changes to your branch before doing anything else:
-
-   git push --force-with-lease
-
-You should see that any conflicts in your PR are now resolved. You can review changes to make sure it contains changes you intended to make.
-
-*If you accidentally sync before pushing, it will trigger a merge. You can use `git merge --abort` to undo the merge.*
-
-You can use `npm run lint:fix` to automatically apply Standard JS rules to resolve formatting differences (tabs vs spaces, line endings, etc).
-
-## Setting up local environment
-
-A quick and dirty guide on how to setup *next-auth* locally to work on it and test out any changes:
+A quick guide on how to setup *next-auth* locally to work on it and test out any changes:
 
 1. Clone the repo:
+```sh
+git clone git@github.com:nextauthjs/next-auth.git
+cd next-auth
+```
 
-       git clone git@github.com:iaincollins/next-auth.git
-       cd next-auth/
+2. Install packages:
+```sh
+npm i
+```
 
-2. Install packages and run the build command:
+3. Populate `.env.local`:
+   
+    Copy `.env.local.example` to `.env.local`, and add your env variables for each provider you want to test.
 
-       npm i
-       npm run build
+> NOTE: You can add any environment variables to .env.local that you would like to use in your dev app.
+> You can find the next-auth config under`pages/api/auth/[...nextauth].js`.
 
-3. Link your project back to your local copy of next auth:
+1. Start the dev application/server and CSS watching:
+```sh
+npm run dev
+```
 
-       cd ../your-application
-       npm link ../next-auth
+Your dev application will be available on ```http://localhost:3000```
 
-4. Finally link React between the repo and the version installed in your project:
-
-       cd ../next-auth
-       npm link ../your-application/node_modules/react
-
-*This is an annoying step and not obvious, but is needed because of how React has been written (otherwise React crashes when you try to use the `useSession()` hook in your project).*
-
-That's it!
-
-Notes: You may need to repeat both `npm link` steps if you install / update additional dependencies with `npm i`.
+That's it! 🎉
 
 If you need an example project to link to, you can use [next-auth-example](https://github.com/iaincollins/next-auth-example).
 
-### Hot reloading
+#### Hot reloading
 
-You might find it helpful to use the `npm run watch` command in the next-auth project, which will automatically (and silently) rebuild JS and CSS files as you edit them.
+When running `npm run dev`, you start a Next.js dev server on `http://localhost:3000`, which includes hot reloading out of the box. Make changes on any of the files in `src` and see the changes immediately.
 
-    cd next-auth/
-    npm run watch
+>NOTE: When working on CSS, you will need to manually refresh the page after changes. (Improving this through a PR is very welcome!)
 
-If you are working on `next-auth/src/client/index.js` hot reloading will work as normal in your Next.js app.
-
-However, if you are working on anything else (e.g. `next-auth/src/server/*` etc) then you will need to *stop and start* your app for changes to apply as **Next.js will not hot reload those changes by default**. To facilitate this, you can try [this webpack plugin](https://www.npmjs.com/package/webpack-clear-require-cache-plugin). Note that the `next.config.js` syntax in the plugin README may be out of date. It should look like this:
-
-```
-const clearRequireCachePlugin = require('webpack-clear-require-cache-plugin')
-
-module.exports = {
-  webpack: (config, {
-    buildId, dev, isServer, defaultLoaders, webpack,
-  }) => {
-    config.plugins.push(clearRequireCachePlugin([
-      /\.next\/server\/static\/development\/pages/,
-      /\.next\/server\/ssr-module-cache.js/,
-      /next-auth/,
-    ]))
-
-    return config
-  },
-}
-```
-
-### Databases
+#### Databases
 
 Included is a Docker Compose file that starts up MySQL, Postgres, and MongoDB databases on localhost.
 
-It will use port 3306, 5432, and 27017 on localhost respectively; it will not work if are running existing databases on localhost.
+It will use port `3306`, `5432`, and `27017` on localhost respectively; please make sure those ports are not used by other services on localhost.
 
 You can start them with `npm run db:start` and stop them with `npm run db:stop`.
 
-You will need Docker installed to be able to start / stop the databases.
+You will need Docker and Docker Compose installed to be able to start / stop the databases.
 
 When stopping the databases, it will reset their contents.
 
-### Testing
+#### Testing
 
 Tests can be run with `npm run test`.
 
@@ -125,3 +81,39 @@ Automated tests are currently crude and limited in functionality, but improvemen
 Currently, to run tests you need to first have started local test databases (e.g. using `npm run db:start`).
 
 The databases can take a few seconds to start up, so you might need to give it a minute before running the tests.
+
+## For maintainers
+
+We use [semantic-release](https://github.com/semantic-release/semantic-release) together with [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0) to automate releases. This makes the maintainenance process easier and less error-prone to human error. Please study the "Conventional Commits" site to understand how to write a good commit message.
+
+When accepting Pull Requests, make sure the following:
+
+* Use "Squash and merge"
+* Make sure you merge contributor PRs into `canary`
+* Rewrite the commit message to conform to the `Conventional Commits` style. Check the "Recommended Scopes" section for further advice.
+* Optionally link issues the PR will resolve (You can add "close" in front of the issue numbers to close the issues automatically, when the PR is merged. `semantic-release` will also comment back to connected issues and PRs, notifying the users that a feature is added/bug fixed, etc.)
+
+### Recommended Scopes
+
+A typical conventional commit looks like this:
+```
+type(scope): title
+
+body
+```
+
+Scope is the part that will help groupping the different commit types in the release notes.
+
+Some recommened scopes are:
+
+- **provider** - Provider related changes. (eg.: "feat(provider): add X provider", "docs(provider): fix typo in X documentation"
+- **adapter** - Adapter related changes. (eg.: "feat(adapter): add X provider", "docs(provider): fix typo in X documentation"
+- **db** - Database related changes. (eg.: "feat(db): add X database", "docs(db): fix typo in X documentation"
+- **deps** - Adding/removing/updating a dependency (eg.: "chore(deps): add X")
+  
+> NOTE: If you are not sure which scope to use, you can simply ignore it. (eg.: "feat: add something"). Adding the correct type already helps a lot when analyzing the commit messages.
+
+
+### Skipping a release
+
+Every commit that contains [skip release] or [release skip] in their message will be excluded from the commit analysis and won't participate in the release type determination. This is useful, if the PR being merged should not trigger a new `npm` release.

LICENSE

@@ -1,6 +1,6 @@
 ISC License
 
-Copyright (c) 2018-2020, Iain Collins
+Copyright (c) 2018-2021, Iain Collins
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above

README.md

@@ -1,7 +1,20 @@
-# NextAuth.js
-
-![Build Test](https://github.com/nextauthjs/next-auth/workflows/Build%20Test/badge.svg)
-![Integration Test](https://github.com/nextauthjs/next-auth/workflows/Integration%20Test/badge.svg)
+<p align="center">
+   <br/>
+   <a href="https://next-auth.js.org" target="_blank"><img width="150px" src="https://next-auth.js.org/img/logo/logo-sm.png" /></a>
+   <h3 align="center">NextAuth.js</h3>
+   <p align="center">Authentication for Next.js</p>
+   <p align="center">
+   Open Source. Full Stack. Own Your Data.
+   </p>
+   <p align="center" style="align: center;">
+      <img src="https://github.com/nextauthjs/next-auth/workflows/Build%20Test/badge.svg" alt="Build Test" />
+      <img src="https://github.com/nextauthjs/next-auth/workflows/Integration%20Test/badge.svg" alt="Integration Test" />
+      <img src="https://img.shields.io/bundlephobia/minzip/next-auth" alt="Bundle Size"/>
+      <img src="https://img.shields.io/npm/dm/next-auth" alt="Downloads" />
+      <img src="https://img.shields.io/github/stars/nextauthjs/next-auth" alt="Github Stars" />
+      <img src="https://img.shields.io/github/v/release/nextauthjs/next-auth?include_prereleases" alt="Github Release" />
+   </p>
+</p>
 
 ## Overview
 
@@ -9,9 +22,15 @@ 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.
 
-[Follow the examples](https://next-auth.js.org/getting-started/example) to see how easy it is to use NextAuth.js for authentication.
+## Getting Started
 
-Install: `npm i next-auth`
+```
+npm install --save next-auth
+```
+
+The easiest way to continue getting started, is to follow the [getting started](https://next-auth.js.org/getting-started/example) section in our docs. 
+
+We also have a section of [tutorials](https://next-auth.js.org/tutorials) for those looking for more specific examples.
 
 See [next-auth.js.org](https://next-auth.js.org) for more information and documentation.
 
@@ -50,15 +69,15 @@ NextAuth.js can be used with or without a database.
 
 Advanced options allow you to define your own routines to handle controlling what accounts are allowed to sign in, for encoding and decoding JSON Web Tokens and to set custom cookie security policies and session properties, so you can control who is able to sign in and how often sessions have to be re-validated. 
 
-### Typescript
+### TypeScript
 
-This library gained Typescript support recently. You can install the types in the following way:
-```
-$ npm i -D @types/next-auth
-```
-In you encounter any issue with them, please raise an issue and add the "typescript" label to it, we'll try to help you with it as soon as possible.
+You can install the appropriate types via the following command:
 
-Alternatively you can raise a PR directly with your fixes on [**DefinitelyTyped**](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/next-auth).
+```
+npm install --save-dev @types/next-auth
+```
+
+As of now, TypeScript is a community effort. If you encounter any problems with the types package, please create an issue at [DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/next-auth). Alternatively, you can open a pull request directly with your fixes there. We welcome anyone to start a discussion on migrating this package to TypeScript, or how to improve the TypeScript experience in general.
 
 ## Example
 
@@ -68,7 +87,7 @@ Alternatively you can raise a PR directly with your fixes on [**DefinitelyTyped*
 import NextAuth from 'next-auth'
 import Providers from 'next-auth/providers'
 
-const options = {
+export default NextAuth({
   providers: [
     // OAuth authentication providers
     Providers.Apple({
@@ -87,45 +106,51 @@ const options = {
   ],
   // SQL or MongoDB database (or leave empty)
   database: process.env.DATABASE_URL
-}
-
-export default (req, res) => NextAuth(req, res, options)
+})
 ```
 
 ### Add React Component
 
 ```javascript
-import React from 'react'
-import { 
-  useSession, 
-  signin, 
-  signout 
+import {
+  useSession, signIn, signOut
 } from 'next-auth/client'
 
-export default function myComponent() {
+export default function Component() {
   const [ session, loading ] = useSession()
-
-  return <p>
-    {!session && <>
-      Not signed in <br/>
-      <button onClick={signin}>Sign in</button>
-    </>}
-    {session && <>
+  if(session) {
+    return <>
       Signed in as {session.user.email} <br/>
-      <button onClick={signout}>Sign out</button>
-    </>}
-  </p>
+      <button onClick={() => signOut()}>Sign out</button>
+    </>
+  }
+  return <>
+    Not signed in <br/>
+    <button onClick={() => signIn()}>Sign in</button>
+  </>
 }
 ```
 
-## Acknowledgement
+## Acknowledgements
 
-[NextAuth.js is possible thanks to its contributors.](https://next-auth.js.org/contributors)
+[NextAuth.js is made possible thanks to all of its contributors.](https://next-auth.js.org/contributors)
 
-## Getting started
-
-[Follow the examples to get started.](https://next-auth.js.org/getting-started/example)
+<a href="https://github.com/nextauthjs/next-auth/graphs/contributors">
+  <img width="500px" src="https://contrib.rocks/image?repo=nextauthjs/next-auth" />
+</a>
+<div>
+<a href="https://vercel.com?utm_source=nextauthjs&utm_campaign=oss">
+<img width="170px" src="https://raw.githubusercontent.com/nextauthjs/next-auth/canary/www/static/img/powered-by-vercel.svg" alt="Powered By Vercel" />
+</a>
+</div>
+<div>
+<p align="left">Thanks to Vercel sponsoring this project by allowing it to be deployed for free for the entire NextAuth.js Team</p>
+</div>
 
 ## Contributing
 
-If you'd like to contribute to you can find useful information in our [Contributing Guide](https://github.com/iaincollins/next-auth/blob/main/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/canary/CONTRIBUTING.md).
+
+## License
+
+ISC

babel.config.json

@@ -1,12 +0,0 @@
-{
-  "presets": [
-    ["@babel/preset-env", { "targets": { "esmodules": true } } ]
-  ],
-  "comments": false,
-  "overrides": [
-    {
-      "test": [ "./src/server/pages/**" ],
-      "presets": [ "preact" ]
-    }
-  ]
-}

components/access-denied.js

@@ -0,0 +1,16 @@
+import { signIn } from 'next-auth/client'
+
+export default function AccessDenied () {
+  return (
+    <>
+      <h1>Access Denied</h1>
+      <p>
+        <a href="/api/auth/signin"
+           onClick={(e) => {
+           e.preventDefault()
+           signIn()
+        }}>You must be signed in to view this page</a>
+      </p>
+    </>
+  )
+}

components/footer.js

@@ -0,0 +1,18 @@
+import Link from 'next/link'
+import styles from './footer.module.css'
+import { version } from 'package.json'
+
+export default function Footer () {
+  return (
+    <footer className={styles.footer}>
+      <hr />
+      <ul className={styles.navItems}>
+        <li className={styles.navItem}><a href='https://next-auth.js.org'>Documentation</a></li>
+        <li className={styles.navItem}><a href='https://www.npmjs.com/package/next-auth'>NPM</a></li>
+        <li className={styles.navItem}><a href='https://github.com/nextauthjs/next-auth-example'>GitHub</a></li>
+        <li className={styles.navItem}><Link href='/policy'><a>Policy</a></Link></li>
+        <li className={styles.navItem}><em>{version}</em></li>
+      </ul>
+    </footer>
+  )
+}

components/footer.module.css

@@ -0,0 +1,14 @@
+.footer {
+  margin-top: 2rem;
+}
+
+.navItems {
+  margin-bottom: 1rem;
+  padding: 0;
+  list-style: none;
+}
+
+.navItem {
+  display: inline-block;
+  margin-right: 1rem;
+}

components/header.js

@@ -0,0 +1,103 @@
+import Link from 'next/link'
+import { signIn, signOut, useSession } from 'next-auth/client'
+import * as client from 'next-auth/client'
+import styles from './header.module.css'
+
+// The approach used in this component shows how to built a sign in and sign out
+// component that works on pages which support both client and server side
+// rendering, and avoids any flash incorrect content on initial page load.
+export default function Header () {
+  const [session, loading] = useSession()
+
+  return (
+    <header>
+      <noscript>
+        <style>{'.nojs-show { opacity: 1; top: 0; }'}</style>
+      </noscript>
+      <div className={styles.signedInStatus}>
+        <p
+          className={`nojs-show ${
+            !session && loading ? styles.loading : styles.loaded
+          }`}
+        >
+          {!session && (
+            <>
+              <span className={styles.notSignedInText}>
+                You are not signed in
+              </span>
+              <a
+                href="/api/auth/signin"
+                className={styles.buttonPrimary}
+                onClick={(e) => {
+                  e.preventDefault()
+                  signIn()
+                }}
+              >
+                Sign in
+              </a>
+            </>
+          )}
+          {session && (
+            <>
+              {session.user.image && (
+                <span
+                  style={{ backgroundImage: `url(${session.user.image})` }}
+                  className={styles.avatar}
+                />
+              )}
+              <span className={styles.signedInText}>
+                <small>Signed in as</small>
+                <br />
+                <strong>{session.user.email || session.user.name}</strong>
+              </span>
+              <a
+                href="/api/auth/signout"
+                className={styles.button}
+                onClick={(e) => {
+                  e.preventDefault()
+                  signOut()
+                }}
+              >
+                Sign out
+              </a>
+            </>
+          )}
+        </p>
+      </div>
+      <nav>
+        <ul className={styles.navItems}>
+          <li className={styles.navItem}>
+            <Link href='/'>
+              <a>Home</a>
+            </Link>
+          </li>
+          <li className={styles.navItem}>
+            <Link href='/client'>
+              <a>Client</a>
+            </Link>
+          </li>
+          <li className={styles.navItem}>
+            <Link href='/server'>
+              <a>Server</a>
+            </Link>
+          </li>
+          <li className={styles.navItem}>
+            <Link href='/protected'>
+              <a>Protected</a>
+            </Link>
+          </li>
+          <li className={styles.navItem}>
+            <Link href='/protected-ssr'>
+              <a>Protected(SSR)</a>
+            </Link>
+          </li>
+          <li className={styles.navItem}>
+            <Link href='/api-example'>
+              <a>API</a>
+            </Link>
+          </li>
+        </ul>
+      </nav>
+    </header>
+  )
+}

components/header.module.css

@@ -0,0 +1,92 @@
+/* Set min-height to avoid page reflow while session loading */
+.signedInStatus {
+  display: block;
+  min-height: 4rem;
+  width: 100%;
+}
+
+.loading,
+.loaded {
+  position: relative;
+  top: 0;
+  opacity: 1;
+  overflow: hidden;
+  border-radius: 0 0 .6rem .6rem;
+  padding: .6rem 1rem;
+  margin: 0;
+  background-color: rgba(0,0,0,.05);
+  transition: all 0.2s ease-in;
+}
+
+.loading {
+  top: -2rem;
+  opacity: 0;
+}
+
+.signedInText,
+.notSignedInText {
+  position: absolute;
+  padding-top: .8rem;
+  left: 1rem;
+  right: 6.5rem;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+  overflow: hidden;
+  display: inherit;  
+  z-index: 1;
+  line-height: 1.3rem;
+}
+
+.signedInText {
+  padding-top: 0rem;
+  left: 4.6rem;
+}
+
+.avatar {
+  border-radius: 2rem;
+  float: left;
+  height: 2.8rem;
+  width: 2.8rem;
+  background-color: white;
+  background-size: cover;
+  background-repeat: no-repeat;
+}
+
+.button,
+.buttonPrimary {
+  float: right;
+  margin-right: -.4rem;
+  font-weight: 500;
+  border-radius: .3rem;
+  cursor: pointer;
+  font-size: 1rem;
+  line-height: 1.4rem;
+  padding: .7rem .8rem;
+  position: relative;
+  z-index: 10;
+  background-color: transparent;
+  color: #555;
+}
+
+.buttonPrimary {
+  background-color: #346df1;
+  border-color: #346df1;
+  color: #fff;
+  text-decoration: none;
+  padding: .7rem 1.4rem;
+}
+
+.buttonPrimary:hover {
+  box-shadow: inset 0 0 5rem rgba(0,0,0,0.2)
+}
+
+.navItems {
+  margin-bottom: 2rem;
+  padding: 0;
+  list-style: none;
+}
+
+.navItem {
+  display: inline-block;
+  margin-right: 1rem;
+}

components/layout.js

@@ -0,0 +1,14 @@
+import Header from 'components/header'
+import Footer from 'components/footer'
+
+export default function Layout ({ children }) {
+  return (
+    <>
+      <Header />
+      <main>
+        {children}
+      </main>
+      <Footer />
+    </>
+  )
+}

config/babel.config.json

@@ -0,0 +1,12 @@
+{
+  "presets": [
+    ["@babel/preset-env", { "targets": { "esmodules": true } }]
+  ],
+  "comments": false,
+  "overrides": [
+    {
+      "test": ["../src/server/pages/**"],
+      "presets": ["preact"]
+    }
+  ]
+}

config/wrap-css.js

@@ -1,6 +1,6 @@
 // Serverless target in Next.js does not work if you try to read in files at runtime
 // that are not JavaScript or JSON (e.g. CSS files).
-// https://github.com/iaincollins/next-auth/issues/281
+// https://github.com/nextauthjs/next-auth/issues/281
 //
 // To work around this issue, this script is a manual step that wraps CSS in a
 // JavaScript file that has the compiled CSS embedded in it, and exports only

jsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "next-auth": ["./src/server"],
+      "next-auth/adapters": ["./src/adapters"],
+      "next-auth/client": ["./src/client"],
+      "next-auth/jwt": ["./src/lib/jwt"],
+      "next-auth/providers": ["./src/providers"]
+    }
+  }
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "next-auth",
-  "version": "3.1.0",
+  "version": "0.0.0-semantically-released",
   "description": "Authentication for Next.js",
   "homepage": "https://next-auth.js.org",
   "repository": "https://github.com/nextauthjs/next-auth.git",
@@ -8,11 +8,12 @@
   "main": "index.js",
   "scripts": {
     "build": "npm run build:js && npm run build:css",
-    "build:js": "babel src --out-dir dist",
-    "build:css": "postcss src/**/*.css --base src --dir dist && node scripts/wrap-css.js",
+    "build:js": "babel --config-file ./config/babel.config.json src --out-dir dist",
+    "build:css": "postcss --config config/postcss.config.js src/**/*.css --base src --dir dist && node config/wrap-css.js",
+    "dev": "next | npm run watch:css",
     "watch": "npm run watch:js | npm run watch:css",
-    "watch:js": "babel --watch src --out-dir dist",
-    "watch:css": "postcss --watch src/**/*.css --base src --dir dist",
+    "watch:js": "babel --config-file ./config/babel.config.json --watch src --out-dir dist",
+    "watch:css": "postcss --config config/postcss.config.js --watch src/**/*.css --base src --dir dist",
     "test:app:start": "docker-compose -f test/docker/app.yml up -d",
     "test:app:rebuild": "npm run build && docker-compose -f test/docker/app.yml up -d --build",
     "test:app:stop": "docker-compose -f test/docker/app.yml down",
@@ -45,49 +46,59 @@
     "futoin-hkdf": "^1.3.2",
     "jose": "^1.27.2",
     "jsonwebtoken": "^8.5.1",
-    "jwt-decode": "^2.2.0",
-    "nodemailer": "^6.4.6",
+    "nodemailer": "^6.4.16",
     "oauth": "^0.9.15",
+    "pkce-challenge": "^2.1.0",
     "preact": "^10.4.1",
     "preact-render-to-string": "^5.1.7",
     "querystring": "^0.2.0",
     "require_optional": "^1.0.1",
-    "typeorm": "^0.2.24"
+    "typeorm": "^0.2.30"
   },
   "peerDependencies": {
-    "react": "^16.13.1",
-    "react-dom": "^16.13.1"
+    "react": "^16.13.1 || ^17",
+    "react-dom": "^16.13.1 || ^17"
   },
   "peerOptionalDependencies": {
     "mongodb": "^3.5.9",
     "mysql": "^2.18.1",
     "mssql": "^6.2.1",
     "pg": "^8.2.1",
-    "@prisma/client": "^2.3.0"
+    "@prisma/client": "^2.12.0"
   },
   "devDependencies": {
     "@babel/cli": "^7.8.4",
     "@babel/core": "^7.9.6",
     "@babel/preset-env": "^7.9.6",
+    "@semantic-release/commit-analyzer": "^8.0.1",
+    "@semantic-release/github": "^7.2.0",
+    "@semantic-release/npm": "7.0.8",
+    "@semantic-release/release-notes-generator": "^9.0.1",
     "autoprefixer": "^9.7.6",
     "babel-preset-preact": "^2.0.0",
+    "conventional-changelog-conventionalcommits": "4.4.0",
     "cssnano": "^4.1.10",
     "dotenv": "^8.2.0",
     "mocha": "^8.1.3",
     "mongodb": "^3.5.9",
     "mssql": "^6.2.1",
     "mysql": "^2.18.1",
+    "next": "^10.0.5",
     "pg": "^8.2.1",
     "postcss-cli": "^7.1.1",
     "postcss-nested": "^4.2.1",
     "puppeteer": "^5.2.1",
     "puppeteer-extra": "^3.1.15",
     "puppeteer-extra-plugin-stealth": "^2.6.1",
-    "standard": "^14.3.3"
+    "react": "^17.0.1",
+    "react-dom": "^17.0.1",
+    "standard": "^16.0.3"
   },
   "standard": {
     "ignore": [
-      "test/"
+      "test/",
+      "pages/",
+      "components/"
     ]
   }
 }

pages/_app.js

@@ -0,0 +1,31 @@
+import { Provider } from 'next-auth/client'
+import './styles.css'
+
+// Use the <Provider> to improve performance and allow components that call
+// `useSession()` anywhere in your application to access the `session` object.
+export default function App ({ Component, pageProps }) {
+  return (
+    <Provider
+      // Provider options are not required but can be useful in situations where
+      // you have a short session maxAge time. Shown here with default values.
+      options={{
+        // Client Max Age controls how often the useSession in the client should
+        // contact the server to sync the session state. Value in seconds.
+        // e.g.
+        // * 0  - Disabled (always use cache value)
+        // * 60 - Sync session state with server if it's older than 60 seconds
+        clientMaxAge: 0,
+        // Keep Alive tells windows / tabs that are signed in to keep sending
+        // a keep alive request (which extends the current session expiry) to
+        // prevent sessions in open windows from expiring. Value in seconds.
+        //
+        // Note: If a session has expired when keep alive is triggered, all open
+        // windows / tabs will be updated to reflect the user is signed out.
+        keepAlive: 0
+      }}
+      session={pageProps.session}
+    >
+      <Component {...pageProps} />
+    </Provider>
+  )
+}

pages/api-example.js

@@ -0,0 +1,17 @@
+import Layout from '../components/layout'
+
+export default function Page () {
+  return (
+    <Layout>
+      <h1>API Example</h1>
+      <p>The examples below show responses from the example API endpoints.</p>
+      <p><em>You must be signed in to see responses.</em></p>
+      <h2>Session</h2>
+      <p>/api/examples/session</p>
+      <iframe src="/api/examples/session"/>
+      <h2>JSON Web Token</h2>
+      <p>/api/examples/jwt</p>
+      <iframe src="/api/examples/jwt"/>
+    </Layout>
+  )
+}

pages/api/auth/[...nextauth].js

@@ -0,0 +1,88 @@
+import NextAuth from "next-auth"
+import Providers from "next-auth/providers"
+
+export default NextAuth({
+  // https://next-auth.js.org/configuration/providers
+  providers: [
+    Providers.GitHub({
+      clientId: process.env.GITHUB_ID,
+      clientSecret: process.env.GITHUB_SECRET,
+    }),
+    Providers.Auth0({
+      clientId: process.env.AUTH0_ID,
+      clientSecret: process.env.AUTH0_SECRET,
+      domain: process.env.AUTH0_DOMAIN,
+      protection: "pkce"
+    })
+  ],
+  // Database optional. MySQL, Maria DB, Postgres and MongoDB are supported.
+  // https://next-auth.js.org/configuration/databases
+  //
+  // Notes:
+  // * You must to install an appropriate node_module for your database
+  // * The Email provider requires a database (OAuth providers do not)
+
+  // The secret should be set to a reasonably long random string.
+  // It is used to sign cookies and to sign and encrypt JSON Web Tokens, unless
+  // a separate secret is defined explicitly for encrypting the JWT.
+
+  session: {
+    // Use JSON Web Tokens for session instead of database sessions.
+    // This option can be used with or without a database for users/accounts.
+    // Note: `jwt` is automatically set to `true` if no database is specified.
+    jwt: true,
+
+    // Seconds - How long until an idle session expires and is no longer valid.
+    // maxAge: 30 * 24 * 60 * 60, // 30 days
+
+    // Seconds - Throttle how frequently to write to database to extend a session.
+    // Use it to limit write operations. Set to 0 to always update the database.
+    // Note: This option is ignored if using JSON Web Tokens
+    // updateAge: 24 * 60 * 60, // 24 hours
+  },
+
+  // JSON Web tokens are only used for sessions if the `jwt: true` session
+  // option is set - or by default if no database is specified.
+  // https://next-auth.js.org/configuration/options#jwt
+  jwt: {
+    encryption: true,
+    secret: process.env.SECRET,
+    // A secret to use for key generation (you should set this explicitly)
+    // secret: 'INp8IvdIyeMcoGAgFGoA61DdBglwwSqnXJZkgz8PSnw',
+    // Set to true to use encryption (default: false)
+    // encryption: true,
+    // You can define your own encode/decode functions for signing and encryption
+    // if you want to override the default behaviour.
+    // encode: async ({ secret, token, maxAge }) => {},
+    // decode: async ({ secret, token, maxAge }) => {},
+  },
+
+  // You can define custom pages to override the built-in pages.
+  // The routes shown here are the default URLs that will be used when a custom
+  // pages is not specified for that route.
+  // https://next-auth.js.org/configuration/pages
+  pages: {
+    // signIn: '/api/auth/signin',  // Displays signin buttons
+    // signOut: '/api/auth/signout', // Displays form with sign out button
+    // error: '/api/auth/error', // Error code passed in query string as ?error=
+    // verifyRequest: '/api/auth/verify-request', // Used for check email page
+    // newUser: null // If set, new users will be directed here on first sign in
+  },
+
+  // Callbacks are asynchronous functions you can use to control what happens
+  // when an action is performed.
+  // https://next-auth.js.org/configuration/callbacks
+  callbacks: {
+    // signIn: async (user, account, profile) => { return Promise.resolve(true) },
+    // redirect: async (url, baseUrl) => { return Promise.resolve(baseUrl) },
+    // session: async (session, user) => { return Promise.resolve(session) },
+    // jwt: async (token, user, account, profile, isNewUser) => { return Promise.resolve(token) }
+  },
+
+  // Events are useful for logging
+  // https://next-auth.js.org/configuration/events
+  events: {},
+
+  // Enable debug messages in the console if you are having problems
+  debug: false,
+})

pages/api/examples/jwt.js

@@ -0,0 +1,9 @@
+// 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
+
+export default async (req, res) => {
+  const token = await jwt.getToken({ req, secret, encryption: true })
+  res.send(JSON.stringify(token, null, 2))
+}

pages/api/examples/protected.js

@@ -0,0 +1,12 @@
+// This is an example of to protect an API route
+import { getSession } from 'next-auth/client'
+
+export default async (req, res) => {
+  const session = await getSession({ req })
+
+  if (session) {
+    res.send({ content: 'This is protected content. You can access this content because you are signed in.' })
+  } else {
+    res.send({ error: 'You must be sign in to view the protected content on this page.' })
+  }
+}

pages/api/examples/session.js

@@ -0,0 +1,7 @@
+// This is an example of how to access a session from an API route
+import { getSession } from 'next-auth/client'
+
+export default async (req, res) => {
+  const session = await getSession({ req })
+  res.send(JSON.stringify(session, null, 2))
+}

pages/client.js

@@ -0,0 +1,22 @@
+import Layout from '../components/layout'
+
+export default function Page () {
+  return (
+    <Layout>
+      <h1>Client Side Rendering</h1>
+      <p>
+        This page uses the <strong>useSession()</strong> React Hook in the <strong>&lt;/Header&gt;</strong> component.
+      </p>
+      <p>
+        The <strong>useSession()</strong> React Hook easy to use and allows pages to render very quickly.
+      </p>
+      <p>
+        The advantage of this approach is that session state is shared between pages by using the <strong>Provider</strong> in <strong>_app.js</strong> so
+        that navigation between pages using <strong>useSession()</strong> is very fast.
+      </p>
+      <p>
+        The disadvantage of <strong>useSession()</strong> is that it requires client side JavaScript.
+      </p>
+    </Layout>
+  )
+}

pages/index.js

@@ -0,0 +1,12 @@
+import Layout from 'components/layout'
+
+export default function Page () {
+  return (
+    <Layout>
+      <h1>NextAuth.js Example</h1>
+      <p>
+        This is an example site to demonstrate how to use <a href='https://next-auth.js.org'>NextAuth.js</a> for authentication.
+      </p>
+    </Layout>
+  )
+}

pages/policy.js

@@ -0,0 +1,30 @@
+import Layout from '../components/layout'
+
+export default function Page () {
+  return (
+    <Layout>
+      <p>
+        This is an example site to demonstrate how to use <a href={`https://next-auth.js.org`}>NextAuth.js</a> for authentication.
+      </p>
+      <h2>Terms of Service</h2>
+      <p>
+        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+        IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+        FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+        AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+        LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+        OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+        SOFTWARE.
+      </p>
+      <h2>Privacy Policy</h2>
+      <p>
+        This site uses JSON Web Tokens and an in-memory database which resets every ~2 hours.
+      </p>
+      <p>
+        Data provided to this site is exclusively used to support signing in
+        and is not passed to any third party services, other than via SMTP or OAuth for the
+        purposes of authentication.
+      </p>
+    </Layout>
+  )
+}

pages/protected-ssr.js

@@ -0,0 +1,37 @@
+// This is an example of how to protect content using server rendering
+import { getSession } from 'next-auth/client'
+import Layout from '../components/layout'
+import AccessDenied from '../components/access-denied'
+
+export default function Page ({ content, session }) {
+  // If no session exists, display access denied message
+  if (!session) { return  <Layout><AccessDenied/></Layout> }
+
+  // If session exists, display content
+  return (
+    <Layout>
+      <h1>Protected Page</h1>
+      <p><strong>{content}</strong></p>
+    </Layout>
+  )
+}
+
+export async function getServerSideProps(context) {
+  const session = await getSession(context)
+  let content = null
+
+  if (session) {
+    const hostname = process.env.NEXTAUTH_URL || 'http://localhost:3000'
+    const options = { headers: { cookie: context.req.headers.cookie } }
+    const res = await fetch(`${hostname}/api/examples/protected`, options)
+    const json = await res.json()
+    if (json.content) { content = json.content }
+  }
+
+  return {
+    props: {
+      session,
+      content
+    }
+  }
+}

pages/protected.js

@@ -0,0 +1,33 @@
+import { useState, useEffect } from 'react'
+import { useSession } from 'next-auth/client'
+import Layout from '../components/layout'
+import AccessDenied from '../components/access-denied'
+
+export default function Page () {
+  const [ session, loading ] = useSession()
+  const [ content , setContent ] = useState()
+
+  // Fetch content from protected route
+  useEffect(()=>{
+    const fetchData = async () => {
+      const res = await fetch('/api/examples/protected')
+      const json = await res.json()
+      if (json.content) { setContent(json.content) }
+    }
+    fetchData()
+  },[session])
+
+  // When rendering client side don't display anything until loading is complete
+  if (typeof window !== 'undefined' && loading) return null
+
+  // If no session exists, display access denied message
+  if (!session) { return  <Layout><AccessDenied/></Layout> }
+
+  // If session exists, display content
+  return (
+    <Layout>
+      <h1>Protected Page</h1>
+      <p><strong>{content}</strong></p>
+    </Layout>
+  )
+}

pages/server.js

@@ -0,0 +1,38 @@
+import { useSession, getSession } from 'next-auth/client'
+import Layout from '../components/layout'
+
+export default function Page () {
+  // As this page uses Server Side Rendering, the `session` will be already
+  // populated on render without needing to go through a loading stage.
+  // This is possible because of the shared context configured in `_app.js` that
+  // is used by `useSession()`.
+  const [ session, loading ] = useSession()
+
+  return (
+    <Layout>
+      <h1>Server Side Rendering</h1>
+      <p>
+        This page uses the universal <strong>getSession()</strong> method in <strong>getServerSideProps()</strong>.
+      </p>
+      <p>
+        Using <strong>getSession()</strong> in <strong>getServerSideProps()</strong> is the recommended approach if you need to
+        support Server Side Rendering with authentication.
+      </p>
+      <p>
+        The advantage of Server Side Rendering is this page does not require client side JavaScript.
+      </p>
+      <p>
+        The disadvantage of Server Side Rendering is that this page is slower to render.
+      </p>
+    </Layout>
+  )
+}
+
+// Export the `session` prop to use sessions with Server Side Rendering
+export async function getServerSideProps(context) {
+  return {
+    props: {
+      session: await getSession(context)
+    }
+  }
+}

pages/styles.css

@@ -0,0 +1,30 @@
+body {
+  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';
+  padding: 0 1rem 1rem 1rem;
+  max-width: 680px;
+  margin: 0 auto;
+  background: #fff;
+  color: #333;
+}
+
+li,
+p {
+  line-height: 1.5rem;
+}
+
+a {
+  font-weight: 500;
+}
+
+hr {
+  border: 1px solid #ddd;
+}
+
+iframe {
+  background: #ccc;
+  border: 1px solid #ccc;
+  height: 10rem;
+  width: 100%;
+  border-radius: .5rem;
+  filter: invert(1);
+}

src/adapters/prisma/index.js

@@ -57,7 +57,7 @@ const Adapter = (config) => {
     async function getUser (id) {
       debug('GET_USER', id)
       try {
-        return prisma[User].findOne({ where: { id } })
+        return prisma[User].findUnique({ where: { id } })
       } catch (error) {
         logger.error('GET_USER_BY_ID_ERROR', error)
         return Promise.reject(new Error('GET_USER_BY_ID_ERROR', error))
@@ -68,7 +68,7 @@ const Adapter = (config) => {
       debug('GET_USER_BY_EMAIL', email)
       try {
         if (!email) { return Promise.resolve(null) }
-        return prisma[User].findOne({ where: { email } })
+        return prisma[User].findUnique({ where: { email } })
       } catch (error) {
         logger.error('GET_USER_BY_EMAIL_ERROR', error)
         return Promise.reject(new Error('GET_USER_BY_EMAIL_ERROR', error))
@@ -78,9 +78,9 @@ const Adapter = (config) => {
     async function getUserByProviderAccountId (providerId, providerAccountId) {
       debug('GET_USER_BY_PROVIDER_ACCOUNT_ID', providerId, providerAccountId)
       try {
-        const account = await prisma[Account].findOne({ where: { compoundId: getCompoundId(providerId, providerAccountId) } })
+        const account = await prisma[Account].findUnique({ where: { compoundId: getCompoundId(providerId, providerAccountId) } })
         if (!account) { return null }
-        return prisma[User].findOne({ where: { id: account.userId } })
+        return prisma[User].findUnique({ where: { id: account.userId } })
       } catch (error) {
         logger.error('GET_USER_BY_PROVIDER_ACCOUNT_ID_ERROR', error)
         return Promise.reject(new Error('GET_USER_BY_PROVIDER_ACCOUNT_ID_ERROR', error))
@@ -174,7 +174,7 @@ const Adapter = (config) => {
     async function getSession (sessionToken) {
       debug('GET_SESSION', sessionToken)
       try {
-        const session = await prisma[Session].findOne({ where: { sessionToken } })
+        const session = await prisma[Session].findUnique({ where: { sessionToken } })
 
         // Check session has not expired (do not return it if it has)
         if (session && session.expires && new Date() > session.expires) {
@@ -219,7 +219,7 @@ const Adapter = (config) => {
         }
 
         const { id, expires } = session
-        return prisma[Session].update({ where: { id }, data: { expires } })
+        return prisma[Session].update({ where: { id }, data: { expires: expires.toISOString() } })
       } catch (error) {
         logger.error('UPDATE_SESSION_ERROR', error)
         return Promise.reject(new Error('UPDATE_SESSION_ERROR', error))
@@ -280,7 +280,7 @@ const Adapter = (config) => {
         // Hash token provided with secret before trying to match it with database
         // @TODO Use bcrypt instead of salted SHA-256 hash for token
         const hashedToken = createHash('sha256').update(`${token}${secret}`).digest('hex')
-        const verificationRequest = await prisma[VerificationRequest].findOne({ where: { token: hashedToken } })
+        const verificationRequest = await prisma[VerificationRequest].findUnique({ where: { token: hashedToken } })
 
         if (verificationRequest && verificationRequest.expires && new Date() > verificationRequest.expires) {
           // Delete verification entry so it cannot be used again

src/client/index.js

@@ -48,7 +48,7 @@ if (typeof window !== 'undefined') {
     window.addEventListener('storage', async (event) => {
       if (event.key === 'nextauth.message') {
         const message = JSON.parse(event.newValue)
-        if (message.event && message.event === 'session' && message.data) {
+        if (message?.event === 'session' && message.data) {
           // Ignore storage events fired from the same window that created them
           if (__NEXTAUTH._clientId === message.clientId) {
             return
@@ -67,9 +67,20 @@ if (typeof window !== 'undefined') {
       }
     })
 
-    // Listen for window focus/blur events
-    window.addEventListener('focus', async (event) => __NEXTAUTH._getSession({ event: 'focus' }))
-    window.addEventListener('blur', async (event) => __NEXTAUTH._getSession({ event: 'blur' }))
+    // Listen for document visibilitychange events
+    let hidden, visibilityChange
+    if (typeof document.hidden !== 'undefined') { // Opera 12.10 and Firefox 18 and later support
+      hidden = 'hidden'
+      visibilityChange = 'visibilitychange'
+    } else if (typeof document.msHidden !== 'undefined') {
+      hidden = 'msHidden'
+      visibilityChange = 'msvisibilitychange'
+    } else if (typeof document.webkitHidden !== 'undefined') {
+      hidden = 'webkitHidden'
+      visibilityChange = 'webkitvisibilitychange'
+    }
+    const handleVisibilityChange = () => !document[hidden] && __NEXTAUTH._getSession({ event: visibilityChange })
+    document.addEventListener('visibilitychange', handleVisibilityChange, false)
   }
 }
 
@@ -104,7 +115,7 @@ const setOptions = ({
 }
 
 // Universal method (client + server)
-const getSession = async ({ req, ctx, triggerEvent = true } = {}) => {
+export const getSession = async ({ req, ctx, triggerEvent = true } = {}) => {
   // If passed 'appContext' via getInitialProps() in _app.js then get the req
   // object from ctx and use that for the req value to allow getSession() to
   // work seemlessly in getInitialProps() on server side pages *and* in _app.js.
@@ -142,7 +153,7 @@ const getProviders = async () => {
 const SessionContext = createContext()
 
 // Client side method
-const useSession = (session) => {
+export const useSession = (session) => {
   // Try to use context if we can
   const value = useContext(SessionContext)
 
@@ -223,24 +234,20 @@ const _useSessionHook = (session) => {
 }
 
 // Client side method
-const signIn = async (provider, args = {}, authParams = {}) => {
+export const signIn = async (provider, args = {}, authorizationParams = {}) => {
   const baseUrl = _apiBaseUrl()
-  const callbackUrl = (args && args.callbackUrl) ? args.callbackUrl : window.location
+  const callbackUrl = args?.callbackUrl ?? window.location
   const providers = await getProviders()
 
   // Redirect to sign in page if no valid provider specified
-  if (!provider || !providers[provider]) {
+  if (!(provider in providers)) {
     // If Provider not recognized, redirect to sign in page
     window.location = `${baseUrl}/signin?callbackUrl=${encodeURIComponent(callbackUrl)}`
   } else {
-    let signInUrl = (providers[provider].type === 'credentials')
+    const signInUrl = (providers[provider].type === 'credentials')
       ? `${baseUrl}/callback/${provider}`
       : `${baseUrl}/signin/${provider}`
 
-    if (authParams) {
-      signInUrl += `?${new URLSearchParams(authParams).toString()}`
-    }
-
     // If is any other provider type, POST to provider URL with CSRF Token,
     // callback URL and any other parameters supplied.
     const fetchOptions = {
@@ -255,15 +262,16 @@ const signIn = async (provider, args = {}, authParams = {}) => {
         json: true
       })
     }
-    const res = await fetch(signInUrl, fetchOptions)
+    const _signInUrl = `${signInUrl}?${_encodedForm(authorizationParams)}`
+    const res = await fetch(_signInUrl, fetchOptions)
     const data = await res.json()
-    window.location = data.url ? data.url : callbackUrl
+    window.location = data.url ?? callbackUrl
   }
 }
 
 // Client side method
-const signOut = async (args = {}) => {
-  const callbackUrl = (args && args.callbackUrl) ? args.callbackUrl : window.location
+export const signOut = async (args = {}) => {
+  const callbackUrl = args.callbackUrl ?? window.location
 
   const baseUrl = _apiBaseUrl()
   const fetchOptions = {
@@ -280,11 +288,11 @@ const signOut = async (args = {}) => {
   const res = await fetch(`${baseUrl}/signout`, fetchOptions)
   const data = await res.json()
   _sendMessage({ event: 'session', data: { trigger: 'signout' } })
-  window.location = data.url ? data.url : callbackUrl
+  window.location = data.url ?? callbackUrl
 }
 
 // Provider to wrap the app in to make session data available globally
-const Provider = ({ children, session, options }) => {
+export const Provider = ({ children, session, options }) => {
   setOptions(options)
   return createElement(SessionContext.Provider, { value: useSession(session) }, children)
 }

src/css/index.css

@@ -1,16 +1,44 @@
 :root {
-  --color-background: #fff;
-  --color-primary: #444;
-  --color-control-border: #bbb;
-  --color-button-active-background: #f9f9f9;
-  --color-button-active-border: #aaa;
   --border-width: 1px;
   --border-radius: .3rem;
   --color-error: #c94b4b;
   --color-info: #157efb;
+}
+
+.__next-auth-theme-auto,
+.__next-auth-theme-light {
+  --color-background: #fff;
+  --color-text: #000;
+  --color-primary: #444;
+  --color-control-border: #bbb;
+  --color-button-active-background: #f9f9f9;
+  --color-button-active-border: #aaa;
   --color-seperator: #ccc;
 }
 
+.__next-auth-theme-dark {
+  --color-background: #000;
+  --color-text: #fff;
+  --color-primary: #ccc;
+  --color-control-border: #555;
+  --color-button-active-background: #060606;
+  --color-button-active-border: #666;
+
+  --color-seperator: #444;
+}
+
+@media (prefers-color-scheme: dark) {
+  .__next-auth-theme-auto {
+    --color-background: #000;
+    --color-text: #fff;
+    --color-primary: #ccc;
+    --color-control-border: #555;
+    --color-button-active-background: #060606;
+    --color-button-active-border: #666;
+    --color-seperator: #444;
+  }
+}
+
 body {
   background-color: var(--color-background);
   margin: 0;
@@ -22,6 +50,11 @@ h1 {
   font-weight: 400;
   margin-bottom: 1.5rem;
   padding: 0 1rem;
+  color: var(--color-text);
+}
+
+p {
+  color: var(--color-text)
 }
 
 form {
@@ -46,7 +79,7 @@ input[type] {
   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 .1rem .2rem rgba(0, 0, 0, .2);
 
   &:focus {
     box-shadow: none;
@@ -63,6 +96,7 @@ p {
 a.button {
   text-decoration: none;
   line-height: 1rem;
+
   &:link,
   &:visited {
     background-color: var(--color-background);
@@ -79,17 +113,17 @@ a.button {
   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 .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);
   font-weight: 500;
   position: relative;
 
   &:hover {
     cursor: pointer;
   }
-  
+
   &: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, .15), inset 0 .1rem .2rem var(--color-background), inset 0 -.1rem .1rem rgba(0, 0, 0, .1);
     background-color: var(--color-button-active-background);
     border-color: var(--color-button-active-border);
     cursor: pointer;
@@ -101,20 +135,21 @@ a.site {
   text-decoration: none;
   font-size: 1rem;
   line-height: 2rem;
+
   &:hover {
     text-decoration: underline;
   }
 }
 
 .page {
-  position: absolute; 
-	width: 100%;
+  position: absolute;
+  width: 100%;
   height: 100%;
   display: table;
   margin: 0;
   padding: 0;
 
-  > div {
+  >div {
     display: table-cell;
     vertical-align: middle;
     text-align: center;
@@ -129,12 +164,14 @@ a.site {
     padding-right: 2rem;
     margin-top: .5rem;
   }
+
   .message {
     margin-bottom: 1.5rem;
   }
 }
 
 .signin {
+
   button,
   a.button,
   input[type="text"] {
@@ -165,7 +202,8 @@ a.site {
     font-weight: 500;
     border-radius: 0.3rem;
     background: var(--color-info);
-    color: #fff;
+    color: var(--color-text);
+
     p {
       text-align: left;
       padding: 0.5rem 1rem;
@@ -174,16 +212,19 @@ a.site {
     }
   }
 
-  > div,
+  >div,
   form {
     display: block;
     margin: 0 auto 0.5rem auto;
+
     input[type] {
       margin-bottom: 0.5rem;
     }
+
     button {
       width: 100%;
     }
+
     max-width: 300px;
   }
 }

src/css/index.js

@@ -4,7 +4,8 @@
 import fs from 'fs'
 import path from 'path'
 
-const pathToCss = path.join(__dirname, '/index.css')
-const css = fs.readFileSync(pathToCss, 'utf8')
+const pathToCss = path.join(process.cwd(), '/dist/css/index.css')
 
-export default () => css
+export default function css () {
+  return fs.readFileSync(pathToCss, 'utf8')
+}

src/lib/errors.js

@@ -1,8 +1,7 @@
-class UnknownError extends Error {
+export class UnknownError extends Error {
   constructor (message) {
     super(message)
     this.name = 'UnknownError'
-    this.message = message
   }
 
   toJSON () {
@@ -16,26 +15,25 @@ class UnknownError extends Error {
   }
 }
 
-class CreateUserError extends UnknownError {
+export class CreateUserError extends UnknownError {
   constructor (message) {
     super(message)
     this.name = 'CreateUserError'
-    this.message = message
   }
 }
 
 // Thrown when an Email address is already associated with an account
-// but the user is trying an oAuth account that is not linked to it.
-class AccountNotLinkedError extends UnknownError {
+// but the user is trying an OAuth account that is not linked to it.
+export class AccountNotLinkedError extends UnknownError {
   constructor (message) {
     super(message)
     this.name = 'AccountNotLinkedError'
-    this.message = message
   }
 }
 
-module.exports = {
-  UnknownError,
-  CreateUserError,
-  AccountNotLinkedError
+export class OAuthCallbackError extends UnknownError {
+  constructor (message) {
+    super(message)
+    this.name = 'OAuthCallbackError'
+  }
 }

src/lib/jwt.js

@@ -1,5 +1,5 @@
+import crypto from 'crypto'
 import jose from 'jose'
-import hkdf from 'futoin-hkdf'
 import logger from './logger'
 
 // Set default algorithm to use for auto-generated signing key
@@ -13,7 +13,7 @@ const DEFAULT_ENCRYPTION_ENABLED = false
 
 const DEFAULT_MAX_AGE = 30 * 24 * 60 * 60 // 30 days
 
-const encode = async ({
+async function encode ({
   token = {},
   maxAge = DEFAULT_MAX_AGE,
   secret,
@@ -28,9 +28,9 @@ const encode = async ({
     zip: 'DEF'
   },
   encryption = DEFAULT_ENCRYPTION_ENABLED
-} = {}) => {
+} = {}) {
   // Signing Key
-  const _signingKey = (signingKey)
+  const _signingKey = signingKey
     ? jose.JWK.asKey(JSON.parse(signingKey))
     : getDerivedSigningKey(secret)
 
@@ -39,18 +39,17 @@ const encode = async ({
 
   if (encryption) {
     // Encryption Key
-    const _encryptionKey = (encryptionKey)
+    const _encryptionKey = encryptionKey
       ? jose.JWK.asKey(JSON.parse(encryptionKey))
       : getDerivedEncryptionKey(secret)
 
     // Encrypt token
     return jose.JWE.encrypt(signedToken, _encryptionKey, encryptionOptions)
-  } else {
-    return signedToken
   }
+  return signedToken
 }
 
-const decode = async ({
+async function decode ({
   secret,
   token,
   maxAge = DEFAULT_MAX_AGE,
@@ -66,14 +65,14 @@ const decode = async ({
     algorithms: [DEFAULT_ENCRYPTION_ALGORITHM]
   },
   encryption = DEFAULT_ENCRYPTION_ENABLED
-} = {}) => {
+} = {}) {
   if (!token) return null
 
   let tokenToVerify = token
 
   if (encryption) {
     // Encryption Key
-    const _encryptionKey = (decryptionKey)
+    const _encryptionKey = decryptionKey
       ? jose.JWK.asKey(JSON.parse(decryptionKey))
       : getDerivedEncryptionKey(secret)
 
@@ -83,7 +82,7 @@ const decode = async ({
   }
 
   // Signing Key
-  const _signingKey = (verificationKey)
+  const _signingKey = verificationKey
     ? jose.JWK.asKey(JSON.parse(verificationKey))
     : getDerivedSigningKey(secret)
 
@@ -91,7 +90,16 @@ const decode = async ({
   return jose.JWT.verify(tokenToVerify, _signingKey, verificationOptions)
 }
 
-const getToken = async (args) => {
+/**
+ * Server-side method to retrieve the JWT from `req`.
+ * @param {{
+ * req: NextApiRequest
+ * secureCookie?: boolean
+ * cookieName?: string
+ * raw?: boolean
+ * }} params
+ */
+async function getToken (params) {
   const {
     req,
     // Use secure prefix for cookie name, unless URL is NEXTAUTH_URL is http://
@@ -99,7 +107,7 @@ const getToken = async (args) => {
     secureCookie = !(!process.env.NEXTAUTH_URL || process.env.NEXTAUTH_URL.startsWith('http://')),
     cookieName = (secureCookie) ? '__Secure-next-auth.session-token' : 'next-auth.session-token',
     raw = false
-  } = args
+  } = params
   if (!req) throw new Error('Must pass `req` to JWT getToken()')
 
   // Try to get token from cookie
@@ -108,7 +116,7 @@ const getToken = async (args) => {
   // 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 && req.headers.authorization.split(' ')[0] === 'Bearer') {
+  if (!token && req.headers.authorization?.split(' ')[0] === 'Bearer') {
     const urlEncodedToken = req.headers.authorization.split(' ')[1]
     token = decodeURIComponent(urlEncodedToken)
   }
@@ -118,8 +126,8 @@ const getToken = async (args) => {
   }
 
   try {
-    return await decode({ token, ...args })
-  } catch (error) {
+    return decode({ token, ...params })
+  } catch {
     return null
   }
 }
@@ -128,24 +136,46 @@ const getToken = async (args) => {
 let DERIVED_SIGNING_KEY_WARNING = false
 let DERIVED_ENCRYPTION_KEY_WARNING = false
 
-const getDerivedSigningKey = (secret) => {
+// 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
+      )
+    )
+  }
+  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, 64, { info: 'NextAuth.js Generated Signing Key', hash: 'SHA-256' })
+  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
 }
 
-const getDerivedEncryptionKey = (secret) => {
+function getDerivedEncryptionKey (secret) {
   if (!DERIVED_ENCRYPTION_KEY_WARNING) {
     logger.warn('JWT_AUTO_GENERATED_ENCRYPTION_KEY')
     DERIVED_ENCRYPTION_KEY_WARNING = true
   }
 
-  const buffer = hkdf(secret, 32, { info: 'NextAuth.js Generated Encryption Key', hash: 'SHA-256' })
+  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
 }

src/lib/logger.js

@@ -1,31 +1,24 @@
 const logger = {
-  error: (errorCode, ...text) => {
-    if (!console) { return }
-    if (text && text.length <= 1) { text = text[0] || '' }
+  error (code, ...text) {
     console.error(
-      `[next-auth][error][${errorCode.toLowerCase()}]`,
-      text,
-      `\nhttps://next-auth.js.org/errors#${errorCode.toLowerCase()}`
+      `[next-auth][error][${code.toLowerCase()}]`,
+      JSON.stringify(text),
+      `\nhttps://next-auth.js.org/errors#${code.toLowerCase()}`
     )
   },
-  warn: (warnCode, ...text) => {
-    if (!console) { return }
-    if (text && text.length <= 1) { text = text[0] || '' }
+  warn (code, ...text) {
     console.warn(
-      `[next-auth][warn][${warnCode.toLowerCase()}]`,
-      text,
-      `\nhttps://next-auth.js.org/warnings#${warnCode.toLowerCase()}`
+      `[next-auth][warn][${code.toLowerCase()}]`,
+      JSON.stringify(text),
+      `\nhttps://next-auth.js.org/warnings#${code.toLowerCase()}`
     )
   },
-  debug: (debugCode, ...text) => {
-    if (!console) { return }
-    if (text && text.length <= 1) { text = text[0] || '' }
-    if (process && process.env && process.env._NEXTAUTH_DEBUG) {
-      console.log(
-        `[next-auth][debug][${debugCode.toLowerCase()}]`,
-        text
-      )
-    }
+  debug (code, ...text) {
+    if (!process?.env?._NEXTAUTH_DEBUG) return
+    console.log(
+      `[next-auth][debug][${code.toLowerCase()}]`,
+      JSON.stringify(text)
+    )
   }
 }
 

src/lib/parse-url.js

@@ -1,8 +1,11 @@
-// 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.
-export default (url) => {
+/**
+ * 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.
+ * @param {string} url
+ */
+export default function parseUrl (url) {
   // Default values
   const defaultHost = 'http://localhost:3000'
   const defaultPath = '/api/auth'
@@ -10,7 +13,7 @@ export default (url) => {
   if (!url) { url = `${defaultHost}${defaultPath}` }
 
   // Default to HTTPS if no protocol explictly specified
-  const protocol = url.match(/^http?:\/\//) ? 'http' : 'https'
+  const protocol = url.startsWith('http:') ? 'http' : 'https'
 
   // Normalize URLs by stripping protocol and no trailing slash
   url = url.replace(/^https?:\/\//, '').replace(/\/$/, '')
@@ -20,8 +23,5 @@ export default (url) => {
   const baseUrl = _host ? `${protocol}://${_host}` : defaultHost
   const basePath = _path.length > 0 ? `/${_path.join('/')}` : defaultPath
 
-  return {
-    baseUrl,
-    basePath
-  }
+  return { baseUrl, basePath }
 }

src/providers/apple.js

@@ -1,5 +1,3 @@
-import jwt from 'jsonwebtoken'
-
 export default (options) => {
   return {
     id: 'apple',
@@ -12,7 +10,6 @@ export default (options) => {
     authorizationUrl: 'https://appleid.apple.com/auth/authorize?response_type=code&id_token&response_mode=form_post',
     profileUrl: null,
     idToken: true,
-    state: false, // Apple doesn't support state verfication
     profile: (profile) => {
       // The name of the user will only return on first login
       return {
@@ -23,30 +20,11 @@ export default (options) => {
     },
     clientId: null,
     clientSecret: {
-      appleId: null,
       teamId: null,
       privateKey: null,
       keyId: null
     },
-    clientSecretCallback: async ({ appleId, keyId, teamId, privateKey }) => {
-      const response = jwt.sign(
-        {
-          iss: teamId,
-          iat: Math.floor(Date.now() / 1000),
-          exp: Math.floor(Date.now() / 1000) + (86400 * 180), // 6 months
-          aud: 'https://appleid.apple.com',
-          sub: appleId
-        },
-        // Automatically convert \\n into \n if found in private key. If the key
-        // is passed in an environment variable \n can get escaped as \\n
-        privateKey.replace(/\\n/g, '\n'),
-        {
-          algorithm: 'ES256',
-          keyid: keyId
-        }
-      )
-      return Promise.resolve(response)
-    },
+    protection: 'none', // REVIEW: Apple does not support state, as far as I know. Can we use "pkce" then?
     ...options
   }
 }

src/providers/azure-ad-b2c.js

@@ -0,0 +1,24 @@
+export default (options) => {
+  const tenant = options.tenantId ? options.tenantId : 'common'
+
+  return {
+    id: 'azure-ad-b2c',
+    name: 'Azure Active Directory B2C',
+    type: 'oauth',
+    version: '2.0',
+    params: {
+      grant_type: 'authorization_code'
+    },
+    accessTokenUrl: `https://login.microsoftonline.com/${tenant}/oauth2/v2.0/token`,
+    authorizationUrl: `https://login.microsoftonline.com/${tenant}/oauth2/v2.0/authorize?response_type=code&response_mode=query`,
+    profileUrl: 'https://graph.microsoft.com/v1.0/me/',
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: profile.displayName,
+        email: profile.userPrincipalName
+      }
+    },
+    ...options
+  }
+}

src/providers/bungie.js

@@ -0,0 +1,30 @@
+export default (options) => {
+  return {
+    id: 'bungie',
+    name: 'Bungie',
+    type: 'oauth',
+    version: '2.0',
+    scope: '',
+    params: { reauth: 'true', grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://www.bungie.net/platform/app/oauth/token/',
+    requestTokenUrl: 'https://www.bungie.net/platform/app/oauth/token/',
+    authorizationUrl: 'https://www.bungie.net/en/OAuth/Authorize?response_type=code',
+    profileUrl: 'https://www.bungie.net/platform/User/GetBungieAccount/{membershipId}/254/',
+    profile: (profile) => {
+      const { bungieNetUser: user } = profile.Response
+
+      return {
+        id: user.membershipId,
+        name: user.displayName,
+        image: `https://www.bungie.net${user.profilePicturePath.startsWith('/') ? '' : '/'}${user.profilePicturePath}`,
+        email: null
+      }
+    },
+    headers: {
+      'X-API-Key': null
+    },
+    clientId: null,
+    clientSecret: null,
+    ...options
+  }
+}

src/providers/discord.js

@@ -7,14 +7,20 @@ export default (options) => {
     scope: 'identify email',
     params: { grant_type: 'authorization_code' },
     accessTokenUrl: 'https://discord.com/api/oauth2/token',
-    authorizationUrl:
-      'https://discord.com/api/oauth2/authorize?response_type=code&prompt=none',
+    authorizationUrl: 'https://discord.com/api/oauth2/authorize?response_type=code&prompt=none',
     profileUrl: 'https://discord.com/api/users/@me',
     profile: (profile) => {
+      if (profile.avatar === null) {
+        const defaultAvatarNumber = parseInt(profile.discriminator) % 5
+        profile.image_url = `https://cdn.discordapp.com/embed/avatars/${defaultAvatarNumber}.png`
+      } else {
+        const format = profile.premium_type === 1 || profile.premium_type === 2 ? 'gif' : 'png'
+        profile.image_url = `https://cdn.discordapp.com/avatars/${profile.id}/${profile.avatar}.${format}`
+      }
       return {
         id: profile.id,
         name: profile.username,
-        image: `https://cdn.discordapp.com/avatars/${profile.id}/${profile.avatar}.png`,
+        image: profile.image_url,
         email: profile.email
       }
     },

src/providers/foursquare.js

@@ -0,0 +1,22 @@
+export default ({ apiVersion, ...options }) => {
+  return {
+    id: 'foursquare',
+    name: 'Foursquare',
+    type: 'oauth',
+    version: '2.0',
+    params: { grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://foursquare.com/oauth2/access_token',
+    authorizationUrl:
+      'https://foursquare.com/oauth2/authenticate?response_type=code',
+    profileUrl: `https://api.foursquare.com/v2/users/self?v=${apiVersion}`,
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: `${profile.firstName} ${profile.lastName}`,
+        image: `${profile.prefix}original${profile.suffix}`,
+        email: profile.contact.email
+      }
+    },
+    ...options
+  }
+}

src/providers/identity-server4.js

@@ -12,7 +12,6 @@ export default (options) => {
     profile: (profile) => {
       return { ...profile, id: profile.sub }
     },
-    setGetAccessTokenAuthHeader: false,
     ...options
   }
 }

src/providers/index.js

@@ -1,51 +1,69 @@
 import Apple from './apple'
 import Atlassian from './atlassian'
 import Auth0 from './auth0'
+import AzureADB2C from './azure-ad-b2c'
 import Basecamp from './basecamp'
 import BattleNet from './battlenet'
 import Box from './box'
-import Credentials from './credentials'
+import Bungie from './bungie'
 import Cognito from './cognito'
+import Credentials from './credentials'
 import Discord from './discord'
 import Email from './email'
 import Facebook from './facebook'
+import Foursquare from './foursquare'
 import FusionAuth from './fusionauth'
 import GitHub from './github'
 import GitLab from './gitlab'
 import Google from './google'
 import IdentityServer4 from './identity-server4'
+import LINE from './line'
 import LinkedIn from './linkedin'
-import Mixer from './mixer'
+import MailRu from './mailru'
+import Netlify from './netlify'
 import Okta from './okta'
+import Reddit from './reddit'
+import Salesforce from './salesforce'
 import Slack from './slack'
 import Spotify from './spotify'
+import Strava from './strava'
 import Twitch from './twitch'
 import Twitter from './twitter'
+import VK from './vk'
 import Yandex from './yandex'
 
 export default {
+  Apple,
   Atlassian,
   Auth0,
-  Apple,
+  AzureADB2C,
   Basecamp,
   BattleNet,
   Box,
-  Credentials,
+  Bungie,
   Cognito,
+  Credentials,
   Discord,
   Email,
   Facebook,
+  Foursquare,
   FusionAuth,
   GitHub,
   GitLab,
   Google,
   IdentityServer4,
+  LINE,
   LinkedIn,
-  Mixer,
+  MailRu,
+  Netlify,
   Okta,
+  Reddit,
+  Salesforce,
   Slack,
   Spotify,
-  Twitter,
+  Strava,
   Twitch,
+  Twitter,
+  VK,
   Yandex
 }

src/providers/line.js

@@ -0,0 +1,22 @@
+export default (options) => {
+  return {
+    id: 'line',
+    name: 'LINE',
+    type: 'oauth',
+    version: '2.0',
+    scope: 'profile openid',
+    params: { grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://api.line.me/oauth2/v2.1/token',
+    authorizationUrl: 'https://access.line.me/oauth2/v2.1/authorize?response_type=code',
+    profileUrl: 'https://api.line.me/v2/profile',
+    profile: (profile) => {
+      return {
+        id: profile.userId,
+        name: profile.displayName,
+        email: null,
+        image: profile.pictureUrl
+      }
+    },
+    ...options
+  }
+}

src/providers/mailru.js

@@ -0,0 +1,25 @@
+export default (options) => {
+  return {
+    id: 'mailru',
+    name: 'Mail.ru',
+    type: 'oauth',
+    version: '2.0',
+    scope: 'userinfo',
+    params: {
+      grant_type: 'authorization_code'
+    },
+    accessTokenUrl: 'https://oauth.mail.ru/token',
+    requestTokenUrl: 'https://oauth.mail.ru/token',
+    authorizationUrl: 'https://oauth.mail.ru/login?response_type=code',
+    profileUrl: 'https://oauth.mail.ru/userinfo',
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: profile.name,
+        email: profile.email,
+        image: profile.image
+      }
+    },
+    ...options
+  }
+}

src/providers/mixer.js

@@ -1,22 +0,0 @@
-export default (options) => {
-  return {
-    id: 'mixer',
-    name: 'Mixer',
-    type: 'oauth',
-    version: '2.0',
-    scope: 'user:details:self',
-    params: { grant_type: 'authorization_code' },
-    accessTokenUrl: 'https://mixer.com/api/v1/oauth/token',
-    authorizationUrl: 'https://mixer.com/oauth/authorize?response_type=code',
-    profileUrl: 'https://mixer.com/api/v1/users/current',
-    profile: (profile) => {
-      return {
-        id: profile.id,
-        name: profile.username,
-        image: profile.avatarUrl,
-        email: profile.email
-      }
-    },
-    ...options
-  }
-}

src/providers/netlify.js

@@ -0,0 +1,21 @@
+export default (options) => {
+  return {
+    id: 'netlify',
+    name: 'Netlify',
+    type: 'oauth',
+    version: '2.0',
+    params: { grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://api.netlify.com/oauth/token',
+    authorizationUrl: 'https://app.netlify.com/authorize?response_type=code',
+    profileUrl: 'https://api.netlify.com/api/v1/user',
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: profile.full_name,
+        email: profile.email,
+        image: profile.avatar_url
+      }
+    },
+    ...options
+  }
+}

src/providers/okta.js

@@ -11,13 +11,12 @@ export default (options) => {
       client_secret: options.clientSecret
     },
     // These will be different depending on the Org.
-    accessTokenUrl: `https://${options.domain}/oauth2/v1/token`,
-    authorizationUrl: `https://${options.domain}/oauth2/v1/authorize/?response_type=code`,
-    profileUrl: `https://${options.domain}/oauth2/v1/userinfo/`,
+    accessTokenUrl: `https://${options.domain}/v1/token`,
+    authorizationUrl: `https://${options.domain}/v1/authorize/?response_type=code`,
+    profileUrl: `https://${options.domain}/v1/userinfo/`,
     profile: (profile) => {
       return { ...profile, id: profile.sub }
     },
-    setGetAccessTokenAuthHeader: false,
     ...options
   }
 }

src/providers/reddit.js

@@ -1,4 +1,3 @@
-// Logging in works but trying to retrieve the profile results in 401 unauthorized
 export default (options) => {
   return {
     id: 'reddit',
@@ -12,12 +11,12 @@ export default (options) => {
       'https://www.reddit.com/api/v1/authorize?response_type=code',
     profileUrl: 'https://oauth.reddit.com/api/v1/me',
     profile: (profile) => {
-      // return {
-      //   id: profile.id,
-      //   name: profile.name,
-      //   image: null,
-      //   email: null,
-      // };
+      return {
+        id: profile.id,
+        name: profile.name,
+        image: null,
+        email: null
+      }
     },
     ...options
   }

src/providers/salesforce.js

@@ -0,0 +1,21 @@
+export default (options) => {
+  return {
+    id: 'salesforce',
+    name: 'Salesforce',
+    type: 'oauth',
+    version: '2.0',
+    params: { display: 'page', grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://login.salesforce.com/services/oauth2/token',
+    authorizationUrl: 'https://login.salesforce.com/services/oauth2/authorize?response_type=code',
+    profileUrl: 'https://login.salesforce.com/services/oauth2/userinfo',
+    protection: 'none', // REVIEW: Can we use "pkce" ?
+    profile: (profile) => {
+      return {
+        ...profile,
+        id: profile.user_id,
+        image: profile.picture
+      }
+    },
+    ...options
+  }
+}

src/providers/slack.js

@@ -4,10 +4,11 @@ export default (options) => {
     name: 'Slack',
     type: 'oauth',
     version: '2.0',
-    scope: 'identity.basic identity.email identity.avatar',
+    scope: [],
     params: { grant_type: 'authorization_code' },
-    accessTokenUrl: 'https://slack.com/api/oauth.access',
-    authorizationUrl: 'https://slack.com/oauth/authorize?response_type=code',
+    accessTokenUrl: 'https://slack.com/api/oauth.v2.access',
+    authorizationUrl: 'https://slack.com/oauth/v2/authorize',
+    authorizationParams: { user_scope: 'identity.basic,identity.email,identity.avatar' },
     profileUrl: 'https://slack.com/api/users.identity',
     profile: (profile) => {
       const { user } = profile

src/providers/spotify.js

@@ -15,7 +15,7 @@ export default (options) => {
         id: profile.id,
         name: profile.display_name,
         email: profile.email,
-        image: profile.images.length > 0 ? profile.images[0].url : undefined
+        image: profile.images?.[0]?.url
       }
     },
     ...options

src/providers/strava.js

@@ -0,0 +1,22 @@
+export default (options) => {
+  return {
+    id: 'strava',
+    name: 'Strava',
+    type: 'oauth',
+    version: '2.0',
+    scope: 'read',
+    params: { grant_type: 'authorization_code' },
+    accessTokenUrl: 'https://www.strava.com/api/v3/oauth/token',
+    authorizationUrl:
+      'https://www.strava.com/api/v3/oauth/authorize?response_type=code',
+    profileUrl: 'https://www.strava.com/api/v3/athlete',
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: profile.firstname,
+        image: profile.profile
+      }
+    },
+    ...options
+  }
+}

src/providers/vk.js

@@ -0,0 +1,30 @@
+export default (options) => {
+  const apiVersion = '5.126' // https://vk.com/dev/versions
+
+  return {
+    id: 'vk',
+    name: 'vk.com',
+    type: 'oauth',
+    version: '2.0',
+    scope: 'email',
+    params: {
+      grant_type: 'authorization_code'
+    },
+    accessTokenUrl: `https://oauth.vk.com/access_token?v=${apiVersion}`,
+    requestTokenUrl: `https://oauth.vk.com/access_token?v=${apiVersion}`,
+    authorizationUrl:
+      `https://oauth.vk.com/authorize?response_type=code&v=${apiVersion}`,
+    profileUrl: `https://api.vk.com/method/users.get?fields=photo_100&v=${apiVersion}`,
+    profile: (result) => {
+      const profile = result.response?.[0] ?? {}
+
+      return {
+        id: profile.id,
+        name: [profile.first_name, profile.last_name].filter(Boolean).join(' '),
+        email: profile.email,
+        image: profile.photo_100
+      }
+    },
+    ...options
+  }
+}

src/server/index.js

@@ -1,19 +1,19 @@
-import { createHash, randomBytes } from 'crypto'
+import adapters from '../adapters'
 import jwt from '../lib/jwt'
 import parseUrl from '../lib/parse-url'
-import cookie from './lib/cookie'
-import callbackUrlHandler from './lib/callback-url-handler'
-import parseProviders from './lib/providers'
-import events from './lib/events'
-import callbacks from './lib/callbacks'
-import providers from './routes/providers'
-import signin from './routes/signin'
-import signout from './routes/signout'
-import callback from './routes/callback'
-import session from './routes/session'
-import pages from './pages'
-import adapters from '../adapters'
 import logger from '../lib/logger'
+import * as cookie from './lib/cookie'
+import * as defaultEvents from './lib/default-events'
+import * as defaultCallbacks from './lib/default-callbacks'
+import parseProviders from './lib/providers'
+import callbackUrlHandler from './lib/callback-url-handler'
+import extendRes from './lib/extend-req'
+import * as routes from './routes'
+import renderPage from './pages'
+import csrfTokenHandler from './lib/csrf-token-handler'
+import createSecret from './lib/create-secret'
+import * as pkce from './lib/oauth/pkce-handler'
+import * as state from './lib/oauth/state-handler'
 
 // To work properly in production with OAuth providers the NEXTAUTH_URL
 // environment variable must be set.
@@ -21,184 +21,72 @@ if (!process.env.NEXTAUTH_URL) {
   logger.warn('NEXTAUTH_URL', 'NEXTAUTH_URL environment variable not set')
 }
 
-export default async (req, res, userSuppliedOptions) => {
+async function NextAuthHandler (req, res, userOptions) {
+  // If debug enabled, set ENV VAR so that logger logs debug messages
+  if (userOptions.debug) {
+    process.env._NEXTAUTH_DEBUG = true
+  }
+
   // To the best of my knowledge, we need to return a promise here
   // to avoid early termination of calls to the serverless function
   // (and then return that promise when we are done) - eslint
   // complains but I'm not sure there is another way to do this.
   return new Promise(async resolve => { // eslint-disable-line no-async-promise-executor
-    // This is passed to all methods that handle responses, and must be called
-    // when they are complete so that the serverless function knows when it is
-    // safe to return and that no more data will be sent.
-    const done = resolve
+    extendRes(req, res, resolve)
+
+    if (!req.query.nextauth) {
+      const error = 'Cannot find [...nextauth].js in pages/api/auth. Make sure the filename is written correctly.'
+
+      logger.error('MISSING_NEXTAUTH_API_ROUTE_ERROR', error)
+      return res.status(500).end(`Error: ${error}`)
+    }
 
-    const { url, query, body } = req
     const {
       nextauth,
       action = nextauth[0],
-      provider = nextauth[1],
+      providerId = nextauth[1],
       error = nextauth[1]
-    } = query
+    } = req.query
 
-    const {
-      csrfToken: csrfTokenFromPost
-    } = body
+    // @todo refactor all existing references to baseUrl and basePath
+    const { basePath, baseUrl } = parseUrl(process.env.NEXTAUTH_URL || process.env.VERCEL_URL)
 
-    // @todo refactor all existing references to site, baseUrl and basePath
-    const parsedUrl = parseUrl(process.env.NEXTAUTH_URL || process.env.VERCEL_URL)
-    const baseUrl = parsedUrl.baseUrl
-    const basePath = parsedUrl.basePath
+    const cookies = {
+      ...cookie.defaultCookies(userOptions.useSecureCookies || baseUrl.startsWith('https://')),
+      // Allow user cookie options to override any cookie settings above
+      ...userOptions.cookies
+    }
+
+    const secret = createSecret({ userOptions, basePath, baseUrl })
+
+    const { csrfToken, csrfTokenVerified } = csrfTokenHandler(req, res, cookies, secret)
+
+    const providers = parseProviders({ providers: userOptions.providers, baseUrl, basePath })
+    const provider = providers.find(({ id }) => id === providerId)
+
+    if (provider &&
+      provider.type === 'oauth' && provider.version?.startsWith('2') &&
+       (!provider.protection && provider.state !== false)
+    ) {
+      provider.protection = 'state' // Default to state, as we did in 3.1 REVIEW: should we use "pkce" or "none" as default?
+    }
+
+    const maxAge = 30 * 24 * 60 * 60 // Sessions expire after 30 days of being idle
 
     // Parse database / adapter
-    let adapter
-    if (userSuppliedOptions.adapter) {
-      // If adapter is provided, use it (advanced usage, overrides database)
-      adapter = userSuppliedOptions.adapter
-    } else if (userSuppliedOptions.database) {
-      // If database URI or config object is provided, use it (simple usage)
-      adapter = adapters.Default(userSuppliedOptions.database)
-    }
-
-    // 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.
-    const secret = userSuppliedOptions.secret || createHash('sha256').update(JSON.stringify({ baseUrl, basePath, ...userSuppliedOptions })).digest('hex')
-
-    // 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/
-    const useSecureCookies = userSuppliedOptions.useSecureCookies || baseUrl.startsWith('https://')
-    const cookiePrefix = useSecureCookies ? '__Secure-' : ''
-
-    // @TODO Review cookie settings (names, options)
-    const cookies = {
-      // 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
-        }
-      },
-      // Allow user cookie options to override any cookie settings above
-      ...userSuppliedOptions.cookies
-    }
-
-    // Session options
-    const sessionOptions = {
-      jwt: false,
-      maxAge: 30 * 24 * 60 * 60, // Sessions expire after 30 days of being idle
-      updateAge: 24 * 60 * 60, // Sessions updated only if session is greater than this value (0 = always, 24*60*60 = every 24 hours)
-      ...userSuppliedOptions.session
-    }
-
-    // JWT options
-    const jwtOptions = {
-      secret, // Use application secret if no keys specified
-      maxAge: sessionOptions.maxAge, // maxAge is dereived from session maxAge,
-      encode: jwt.encode,
-      decode: jwt.decode,
-      ...userSuppliedOptions.jwt
-    }
-
-    // If no adapter specified, force use of JSON Web Tokens (stateless)
-    if (!adapter) {
-      sessionOptions.jwt = true
-    }
-
-    // Event messages
-    const eventsOptions = {
-      ...events,
-      ...userSuppliedOptions.events
-    }
-
-    // Callback functions
-    const callbacksOptions = {
-      ...callbacks,
-      ...userSuppliedOptions.callbacks
-    }
-
-    // Ensure CSRF Token cookie is set for any subsequent requests.
-    // Used as part of the strateigy for mitigation for CSRF tokens.
-    //
-    // Creates a cookie like 'next-auth.csrf-token' with the value 'token|hash',
-    // where 'token' is the CSRF token and 'hash' is a hash made of the token and
-    // the secret, and the two values are joined by a pipe '|'. By storing the
-    // value and the hash of the value (with the secret used as a salt) we can
-    // verify the cookie was set by the server and not by a malicous attacker.
-    //
-    // For more details, see the following OWASP links:
-    // 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
-    let csrfToken
-    let csrfTokenVerified = false
-    if (req.cookies[cookies.csrfToken.name]) {
-      const [csrfTokenValue, csrfTokenHash] = req.cookies[cookies.csrfToken.name].split('|')
-      if (csrfTokenHash === createHash('sha256').update(`${csrfTokenValue}${secret}`).digest('hex')) {
-        // If hash matches then we trust the CSRF token value
-        csrfToken = csrfTokenValue
-
-        // If this is a POST request and the CSRF Token in the Post request matches
-        // the cookie we have already verified is one we have set, then token is verified!
-        if (req.method === 'POST' && csrfToken === csrfTokenFromPost) { csrfTokenVerified = true }
-      }
-    }
-    if (!csrfToken) {
-      // If no csrfToken - because it's not been set yet, or because the hash doesn't match
-      // (e.g. because it's been modifed or because the secret has changed) create a new token.
-      csrfToken = randomBytes(32).toString('hex')
-      const newCsrfTokenCookie = `${csrfToken}|${createHash('sha256').update(`${csrfToken}${secret}`).digest('hex')}`
-      cookie.set(res, cookies.csrfToken.name, newCsrfTokenCookie, cookies.csrfToken.options)
-    }
-
-    // Helper method for handling redirects, this is passed to all routes
-    // @TODO Refactor into a lib instead of passing as an option
-    //       e.g. and call as redirect(req, res, url)
-    const redirect = (redirectUrl) => {
-      const reponseAsJson = !!((req.body && req.body.json === 'true'))
-      if (reponseAsJson) {
-        res.json({ url: redirectUrl })
-      } else {
-        res.status(302).setHeader('Location', redirectUrl)
-        res.end()
-      }
-      return done()
-    }
+    // If adapter is provided, use it (advanced usage, overrides database)
+    // If database URI or config object is provided, use it (simple usage)
+    const adapter = userOptions.adapter ?? (userOptions.database && adapters.Default(userOptions.database))
 
     // User provided options are overriden by other options,
     // except for the options with special handling above
-    const options = {
-      // Defaults options can be overidden
-      debug: false, // Enable debug messages to be displayed
-      pages: {}, // Custom pages (e.g. sign in, sign out, errors)
+    req.options = {
+      debug: false,
+      pages: {},
+      theme: 'auto',
       // Custom options override defaults
-      ...userSuppliedOptions,
-      // These computed settings can values in userSuppliedOptions but override them
+      ...userOptions,
+      // These computed settings can have values in userOptions but we override them
       // and are request-specific.
       adapter,
       baseUrl,
@@ -208,108 +96,137 @@ export default async (req, res, userSuppliedOptions) => {
       cookies,
       secret,
       csrfToken,
-      providers: parseProviders(userSuppliedOptions.providers, baseUrl, basePath),
-      session: sessionOptions,
-      jwt: jwtOptions,
-      events: eventsOptions,
-      callbacks: callbacksOptions,
-      callbackUrl: baseUrl,
-      redirect
+      providers,
+      // Session options
+      session: {
+        jwt: !adapter, // If no adapter specified, force use of JSON Web Tokens (stateless)
+        maxAge,
+        updateAge: 24 * 60 * 60, // Sessions updated only if session is greater than this value (0 = always, 24*60*60 = every 24 hours)
+        ...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: {
+        ...defaultEvents,
+        ...userOptions.events
+      },
+      // Callback functions
+      callbacks: {
+        ...defaultCallbacks,
+        ...userOptions.callbacks
+      },
+      pkce: {}
     }
 
-    // If debug enabled, set ENV VAR so that logger logs debug messages
-    if (options.debug === true) { process.env._NEXTAUTH_DEBUG = true }
+    await callbackUrlHandler(req, res)
 
-    // Get / Set callback URL based on query param / cookie + validation
-    options.callbackUrl = await callbackUrlHandler(req, res, options)
+    const render = renderPage(req, res)
+    const { pages } = req.options
 
     if (req.method === 'GET') {
       switch (action) {
         case 'providers':
-          providers(req, res, options, done)
-          break
+          return routes.providers(req, res)
         case 'session':
-          session(req, res, options, done)
-          break
+          return routes.session(req, res)
         case 'csrf':
-          res.json({ csrfToken })
-          return done()
+          return res.json({ csrfToken })
         case 'signin':
-          if (options.pages.signIn) {
-            let redirectUrl = `${options.pages.signIn}${options.pages.signIn.includes('?') ? '&' : '?'}callbackUrl=${options.callbackUrl}`
-            if (req.query.error) { redirectUrl = `${redirectUrl}&error=${req.query.error}` }
-            return redirect(redirectUrl)
+          if (pages.signIn) {
+            let signinUrl = `${pages.signIn}${pages.signIn.includes('?') ? '&' : '?'}callbackUrl=${req.options.callbackUrl}`
+            if (error) { signinUrl = `${signinUrl}&error=${error}` }
+            return res.redirect(signinUrl)
           }
 
-          pages.render(req, res, 'signin', { baseUrl, basePath, providers: Object.values(options.providers), callbackUrl: options.callbackUrl, csrfToken }, done)
-          break
+          return render.signin()
         case 'signout':
-          if (options.pages.signOut) { return redirect(`${options.pages.signOut}${options.pages.signOut.includes('?') ? '&' : '?'}error=${error}`) }
-
-          pages.render(req, res, 'signout', { baseUrl, basePath, csrfToken, callbackUrl: options.callbackUrl }, done)
-          break
+          if (pages.signOut) {
+            return res.redirect(`${pages.signOut}${pages.signOut.includes('?') ? '&' : '?'}error=${error}`)
+          }
+          return render.signout()
         case 'callback':
-          if (provider && options.providers[provider]) {
-            callback(req, res, options, done)
-          } else {
-            res.status(400).end(`Error: HTTP GET is not supported for ${url}`)
-            return done()
+          if (provider) {
+            if (await pkce.handleCallback(req, res)) return
+            if (await state.handleCallback(req, res)) return
+            return routes.callback(req, res)
           }
           break
         case 'verify-request':
-          if (options.pages.verifyRequest) { return redirect(options.pages.verifyRequest) }
-
-          pages.render(req, res, 'verify-request', { baseUrl }, done)
-          break
+          if (pages.verifyRequest) {
+            return res.redirect(pages.verifyRequest)
+          }
+          return render.verifyRequest()
         case 'error':
-          if (options.pages.error) { return redirect(`${options.pages.error}${options.pages.error.includes('?') ? '&' : '?'}error=${error}`) }
+          if (pages.error) {
+            return res.redirect(`${pages.error}${pages.error.includes('?') ? '&' : '?'}error=${error}`)
+          }
 
-          pages.render(req, res, 'error', { baseUrl, basePath, error }, done)
-          break
+          // These error messages are displayed in line on the sign in page
+          if ([
+            'Signin',
+            'OAuthSignin',
+            'OAuthCallback',
+            'OAuthCreateAccount',
+            'EmailCreateAccount',
+            'Callback',
+            'OAuthAccountNotLinked',
+            'EmailSignin',
+            'CredentialsSignin'
+          ].includes(error)) {
+            return res.redirect(`${baseUrl}${basePath}/signin?error=${error}`)
+          }
+
+          return render.error({ error })
         default:
-          res.status(404).end()
-          return done()
       }
     } else if (req.method === 'POST') {
       switch (action) {
         case 'signin':
           // Verified CSRF Token required for all sign in routes
-          if (!csrfTokenVerified) {
-            return redirect(`${baseUrl}${basePath}/signin?csrf=true`)
+          if (csrfTokenVerified && provider) {
+            if (await pkce.handleSignin(req, res)) return
+            if (await state.handleSignin(req, res)) return
+            return routes.signin(req, res)
           }
 
-          if (provider && options.providers[provider]) {
-            signin(req, res, options, done)
-          }
-          break
+          return res.redirect(`${baseUrl}${basePath}/signin?csrf=true`)
         case 'signout':
           // Verified CSRF Token required for signout
-          if (!csrfTokenVerified) {
-            return redirect(`${baseUrl}${basePath}/signout?csrf=true`)
+          if (csrfTokenVerified) {
+            return routes.signout(req, res)
           }
-
-          signout(req, res, options, done)
-          break
+          return res.redirect(`${baseUrl}${basePath}/signout?csrf=true`)
         case 'callback':
-          if (provider && options.providers[provider]) {
+          if (provider) {
             // Verified CSRF Token required for credentials providers only
-            if (options.providers[provider].type === 'credentials' && !csrfTokenVerified) {
-              return redirect(`${baseUrl}${basePath}/signin?csrf=true`)
+            if (provider.type === 'credentials' && !csrfTokenVerified) {
+              return res.redirect(`${baseUrl}${basePath}/signin?csrf=true`)
             }
 
-            callback(req, res, options, done)
-          } else {
-            res.status(400).end(`Error: HTTP POST is not supported for ${url}`)
-            return done()
+            if (await pkce.handleCallback(req, res)) return
+            if (await state.handleCallback(req, res)) return
+            return routes.callback(req, res)
           }
           break
         default:
-          res.status(400).end(`Error: HTTP POST is not supported for ${url}`)
-          return done()
       }
-    } else {
-      res.status(400).end(`Error: HTTP ${req.method} is not supported for ${url}`)
-      return done()
     }
+    return res.status(400).end(`Error: HTTP ${req.method} is not supported for ${req.url}`)
   })
 }
+
+/** Tha main entry point to next-auth */
+export default function NextAuth (...args) {
+  if (args.length === 1) {
+    return (req, res) => NextAuthHandler(req, res, args[0])
+  }
+
+  return NextAuthHandler(...args)
+}

src/server/lib/callback-handler.js

@@ -1,223 +1,221 @@
-// This function handles the complex flow of signing users in, and either creating,
-// linking (or not linking) accounts depending on if the user is currently logged
-// in, if they have account already and the authentication mechanism they are using.
-//
-// It prevents insecure behaviour, such as linking oAuth accounts unless a user is
-// signed in and authenticated with an existing valid account.
-//
-// All verification (e.g. oAuth flows or email address verificaiton flows) are
-// done prior to this handler being called to avoid additonal complexity in this
-// handler.
 import { AccountNotLinkedError } from '../../lib/errors'
 import dispatchEvent from '../lib/dispatch-event'
 
-export default async (sessionToken, profile, providerAccount, options) => {
-  try {
-    // Input validation
-    if (!profile) { throw new Error('Missing profile') }
-    if (!providerAccount || !providerAccount.id || !providerAccount.type) { throw new Error('Missing or invalid provider account') }
+/**
+ * This function handles the complex flow of signing users in, and either creating,
+ * linking (or not linking) accounts depending on if the user is currently logged
+ * in, if they have account already and the authentication mechanism they are using.
+ *
+ * It prevents insecure behaviour, such as linking OAuth accounts unless a user is
+ * signed in and authenticated with an existing valid account.
+ *
+ * All verification (e.g. OAuth flows or email address verificaiton flows) are
+ * done prior to this handler being called to avoid additonal complexity in this
+ * handler.
+ */
+export default async function callbackHandler (sessionToken, profile, providerAccount, options) {
+  // Input validation
+  if (!profile) throw new Error('Missing profile')
+  if (!providerAccount?.id || !providerAccount.type) throw new Error('Missing or invalid provider account')
+  if (!['email', 'oauth'].includes(providerAccount.type)) throw new Error('Provider not supported')
 
-    const { adapter, jwt, events } = options
-
-    const useJwtSession = options.session.jwt
-
-    // If no adapter is configured then we don't have a database and cannot
-    // persist data; in this mode we just return a dummy session object.
-    if (!adapter) {
-      return {
-        user: profile,
-        account: providerAccount,
-        session: {}
-      }
+  const {
+    adapter,
+    jwt,
+    events,
+    session: {
+      jwt: useJwtSession
     }
+  } = options
 
-    const {
-      createUser,
-      updateUser,
-      getUser,
-      getUserByProviderAccountId,
-      getUserByEmail,
-      linkAccount,
-      createSession,
-      getSession,
-      deleteSession
-    } = await adapter.getAdapter(options)
+  // If no adapter is configured then we don't have a database and cannot
+  // persist data; in this mode we just return a dummy session object.
+  if (!adapter) {
+    return {
+      user: profile,
+      account: providerAccount,
+      session: {}
+    }
+  }
 
-    let session = null
-    let user = null
-    let isSignedIn = null
-    let isNewUser = false
+  const {
+    createUser,
+    updateUser,
+    getUser,
+    getUserByProviderAccountId,
+    getUserByEmail,
+    linkAccount,
+    createSession,
+    getSession,
+    deleteSession
+  } = await adapter.getAdapter(options)
 
-    if (sessionToken) {
-      if (useJwtSession) {
-        try {
-          session = await jwt.decode({ ...jwt, token: sessionToken })
-          if (session && session.user) {
-            user = await getUser(session.user.id)
-            isSignedIn = !!user
-          }
-        } catch (e) {
-          // If session can't be verified, treat as no session
-        }
-      } else {
-        session = await getSession(sessionToken)
-        if (session && session.userId) {
-          user = await getUser(session.userId)
+  let session = null
+  let user = null
+  let isSignedIn = null
+  let isNewUser = false
+
+  if (sessionToken) {
+    if (useJwtSession) {
+      try {
+        session = await jwt.decode({ ...jwt, token: sessionToken })
+        if (session?.sub) {
+          user = await getUser(session.sub)
           isSignedIn = !!user
         }
+      } catch {
+        // If session can't be verified, treat as no session
       }
     }
+    session = await getSession(sessionToken)
+    if (session?.userId) {
+      user = await getUser(session.userId)
+      isSignedIn = !!user
+    }
+  }
 
-    if (providerAccount.type === 'email') {
-      // If signing in with an email, check if an account with the same email address exists already
-      const userByEmail = profile.email ? await getUserByEmail(profile.email) : null
-      if (userByEmail) {
-        // If they are not already signed in as the same user, this flow will
-        // sign them out of the current session and sign them in as the new user
-        if (isSignedIn) {
-          if (user.id !== userByEmail.id && !useJwtSession) {
-            // Delete existing session if they are currently signed in as another user.
-            // This will switch user accounts for the session in cases where the user was
-            // already logged in with a different account.
-            await deleteSession(sessionToken)
-          }
+  if (providerAccount.type === 'email') {
+    // If signing in with an email, check if an account with the same email address exists already
+    const userByEmail = profile.email ? await getUserByEmail(profile.email) : null
+    if (userByEmail) {
+      // If they are not already signed in as the same user, this flow will
+      // sign them out of the current session and sign them in as the new user
+      if (isSignedIn) {
+        if (user.id !== userByEmail.id && !useJwtSession) {
+          // Delete existing session if they are currently signed in as another user.
+          // This will switch user accounts for the session in cases where the user was
+          // already logged in with a different account.
+          await deleteSession(sessionToken)
         }
-
-        // Update emailVerified property on the user object
-        const currentDate = new Date()
-        user = await updateUser({ ...userByEmail, emailVerified: currentDate })
-        await dispatchEvent(events.updateUser, user)
-      } else {
-        // Create user account if there isn't one for the email address already
-        const currentDate = new Date()
-        user = await createUser({ ...profile, emailVerified: currentDate })
-        await dispatchEvent(events.createUser, user)
-        isNewUser = true
       }
 
-      // Create new session
-      session = useJwtSession ? {} : await createSession(user)
+      // Update emailVerified property on the user object
+      const currentDate = new Date()
+      user = await updateUser({ ...userByEmail, emailVerified: currentDate })
+      await dispatchEvent(events.updateUser, user)
+    } else {
+      // Create user account if there isn't one for the email address already
+      const currentDate = new Date()
+      user = await createUser({ ...profile, emailVerified: currentDate })
+      await dispatchEvent(events.createUser, user)
+      isNewUser = true
+    }
 
+    // Create new session
+    session = useJwtSession ? {} : await createSession(user)
+
+    return {
+      session,
+      user,
+      isNewUser
+    }
+  } else if (providerAccount.type === 'oauth') {
+    // If signing in with oauth account, check to see if the account exists already
+    const userByProviderAccountId = await getUserByProviderAccountId(providerAccount.provider, providerAccount.id)
+    if (userByProviderAccountId) {
+      if (isSignedIn) {
+        // If the user is already signed in with this account, we don't need to do anything
+        // Note: These are cast as strings here to ensure they match as in
+        // some flows (e.g. JWT with a database) one of the values might be a
+        // string and the other might be an ObjectID and would otherwise fail.
+        if (`${userByProviderAccountId.id}` === `${user.id}`) {
+          return {
+            session,
+            user,
+            isNewUser
+          }
+        }
+        // If the user is currently signed in, but the new account they are signing in
+        // with is already associated with another account, then we cannot link them
+        // and need to return an error.
+        throw new AccountNotLinkedError()
+      }
+      // If there is no active session, but the account being signed in with is already
+      // associated with a valid user then create session to sign the user in.
+      session = useJwtSession ? {} : await createSession(userByProviderAccountId)
+      return {
+        session,
+        user: userByProviderAccountId,
+        isNewUser
+      }
+    } else {
+      if (isSignedIn) {
+        // If the user is already signed in and the OAuth account isn't already associated
+        // with another user account then we can go ahead and link the accounts safely.
+        await linkAccount(
+          user.id,
+          providerAccount.provider,
+          providerAccount.type,
+          providerAccount.id,
+          providerAccount.refreshToken,
+          providerAccount.accessToken,
+          providerAccount.accessTokenExpires
+        )
+        await dispatchEvent(events.linkAccount, { user, providerAccount: providerAccount })
+
+        // As they are already signed in, we don't need to do anything after linking them
+        return {
+          session,
+          user,
+          isNewUser
+        }
+      }
+
+      // If the user is not signed in and it looks like a new OAuth account then we
+      // check there also isn't an user account already associated with the same
+      // email address as the one in the OAuth profile.
+      //
+      // This step is often overlooked in OAuth implementations, but covers the following cases:
+      //
+      // 1. It makes it harder for someone to accidentally create two accounts.
+      //    e.g. by signin in with email, then again with an oauth account connected to the same email.
+      // 2. It makes it harder to hijack a user account using a 3rd party OAuth account.
+      //    e.g. by creating an oauth account then changing the email address associated with it.
+      //
+      // It's quite common for services to automatically link accounts in this case, but it's
+      // better practice to require the user to sign in *then* link accounts to be sure
+      // someone is not exploiting a problem with a third party OAuth service.
+      //
+      // OAuth providers should require email address verification to prevent this, but in
+      // practice that is not always the case; this helps protect against that.
+      const userByEmail = profile.email ? await getUserByEmail(profile.email) : null
+      if (userByEmail) {
+        // We end up here when we don't have an account with the same [provider].id *BUT*
+        // we do already have an account with the same email address as the one in the
+        // OAuth profile the user has just tried to sign in with.
+        //
+        // We don't want to have two accounts with the same email address, and we don't
+        // want to link them in case it's not safe to do so, so instead we prompt the user
+        // to sign in via email to verify their identity and then link the accounts.
+        throw new AccountNotLinkedError()
+      }
+      // If the current user is not logged in and the profile isn't linked to any user
+      // accounts (by email or provider account id)...
+      //
+      // If no account matching the same [provider].id or .email exists, we can
+      // create a new account for the user, link it to the OAuth acccount and
+      // create a new session for them so they are signed in with it.
+      user = await createUser(profile)
+      await dispatchEvent(events.createUser, user)
+
+      await linkAccount(
+        user.id,
+        providerAccount.provider,
+        providerAccount.type,
+        providerAccount.id,
+        providerAccount.refreshToken,
+        providerAccount.accessToken,
+        providerAccount.accessTokenExpires
+      )
+      await dispatchEvent(events.linkAccount, { user, providerAccount: providerAccount })
+
+      session = useJwtSession ? {} : await createSession(user)
+      isNewUser = true
       return {
         session,
         user,
         isNewUser
       }
-    } else if (providerAccount.type === 'oauth') {
-      // If signing in with oauth account, check to see if the account exists already
-      const userByProviderAccountId = await getUserByProviderAccountId(providerAccount.provider, providerAccount.id)
-      if (userByProviderAccountId) {
-        if (isSignedIn) {
-          // If the user is already signed in with this account, we don't need to do anything
-          // Note: These are cast as strings here to ensure they match as in
-          // some flows (e.g. JWT with a database) one of the values might be a
-          // string and the other might be an ObjectID and would otherwise fail.
-          if (`${userByProviderAccountId.id}` === `${user.id}`) {
-            return {
-              session,
-              user,
-              isNewUser
-            }
-          } else {
-            // If the user is currently signed in, but the new account they are signing in
-            // with is already associated with another account, then we cannot link them
-            // and need to return an error.
-            throw new AccountNotLinkedError()
-          }
-        } else {
-          // If there is no active session, but the account being signed in with is already
-          // associated with a valid user then create session to sign the user in.
-          session = useJwtSession ? {} : await createSession(userByProviderAccountId)
-          return {
-            session,
-            user: userByProviderAccountId,
-            isNewUser
-          }
-        }
-      } else {
-        if (isSignedIn) {
-          // If the user is already signed in and the oAuth account isn't already associated
-          // with another user account then we can go ahead and link the accounts safely.
-          await linkAccount(
-            user.id,
-            providerAccount.provider,
-            providerAccount.type,
-            providerAccount.id,
-            providerAccount.refreshToken,
-            providerAccount.accessToken,
-            providerAccount.accessTokenExpires
-          )
-          await dispatchEvent(events.linkAccount, { user, providerAccount })
-
-          // As they are already signed in, we don't need to do anything after linking them
-          return {
-            session,
-            user,
-            isNewUser
-          }
-        }
-
-        // If the user is not signed in and it looks like a new oAuth account then we
-        // check there also isn't an user account already associated with the same
-        // email address as the one in the oAuth profile.
-        //
-        // This step is often overlooked in oAuth implementations, but covers the following cases:
-        //
-        // 1. It makes it harder for someone to accidentally create two accounts.
-        //    e.g. by signin in with email, then again with an oauth account connected to the same email.
-        // 2. It makes it harder to hijack a user account using a 3rd party oAuth account.
-        //    e.g. by creating an oauth account then changing the email address associated with it.
-        //
-        // It's quite common for services to automatically link accounts in this case, but it's
-        // better practice to require the user to sign in *then* link accounts to be sure
-        // someone is not exploiting a problem with a third party oAuth service.
-        //
-        // oAuth providers should require email address verification to prevent this, but in
-        // practice that is not always the case; this helps protect against that.
-        const userByEmail = profile.email ? await getUserByEmail(profile.email) : null
-        if (userByEmail) {
-          // We end up here when we don't have an account with the same [provider].id *BUT*
-          // we do already have an account with the same email address as the one in the
-          // oAuth profile the user has just tried to sign in with.
-          //
-          // We don't want to have two accounts with the same email address, and we don't
-          // want to link them in case it's not safe to do so, so instead we prompt the user
-          // to sign in via email to verify their identity and then link the accounts.
-          throw new AccountNotLinkedError()
-        } else {
-          // If the current user is not logged in and the profile isn't linked to any user
-          // accounts (by email or provider account id)...
-          //
-          // If no account matching the same [provider].id or .email exists, we can
-          // create a new account for the user, link it to the oAuth acccount and
-          // create a new session for them so they are signed in with it.
-          user = await createUser(profile)
-          await dispatchEvent(events.createUser, user)
-
-          await linkAccount(
-            user.id,
-            providerAccount.provider,
-            providerAccount.type,
-            providerAccount.id,
-            providerAccount.refreshToken,
-            providerAccount.accessToken,
-            providerAccount.accessTokenExpires
-          )
-          await dispatchEvent(events.linkAccount, { user, providerAccount })
-
-          session = useJwtSession ? {} : await createSession(user)
-          isNewUser = true
-          return {
-            session,
-            user,
-            isNewUser
-          }
-        }
-      }
-    } else {
-      return Promise.reject(new Error('Provider not supported'))
     }
-  } catch (error) {
-    return Promise.reject(error)
   }
 }

src/server/lib/callback-url-handler.js

@@ -1,14 +1,18 @@
-import cookie from '../lib/cookie'
+import * as cookie from '../lib/cookie'
 
-export default async (req, res, options) => {
+/**
+ * Get callback URL based on query param / cookie + validation,
+ * and add it to `req.options.callbackUrl`.
+ * @note: `req.options` must already be defined when called.
+ */
+export default async function callbackUrlHandler (req, res) {
   const { query } = req
   const { body } = req
-  const { cookies, baseUrl, defaultCallbackUrl, callbacks } = options
+  const { cookies, baseUrl, defaultCallbackUrl, callbacks } = req.options
 
   // Handle preserving and validating callback URLs
   // If no defaultCallbackUrl option specified, default to the homepage for the site
   let callbackUrl = defaultCallbackUrl || baseUrl
-
   // Try reading callbackUrlParamValue from request body (form submission) then from query param (get request)
   const callbackUrlParamValue = body.callbackUrl || query.callbackUrl || null
   const callbackUrlCookieValue = req.cookies[cookies.callbackUrl.name] || null
@@ -21,7 +25,9 @@ export default async (req, res, options) => {
   }
 
   // Save callback URL in a cookie so that can be used for subsequent requests in signin/signout/callback flow
-  if (callbackUrl && (callbackUrl !== callbackUrlCookieValue)) { cookie.set(res, cookies.callbackUrl.name, callbackUrl, cookies.callbackUrl.options) }
+  if (callbackUrl && (callbackUrl !== callbackUrlCookieValue)) {
+    cookie.set(res, cookies.callbackUrl.name, callbackUrl, cookies.callbackUrl.options)
+  }
 
-  return Promise.resolve(callbackUrl)
+  req.options.callbackUrl = callbackUrl
 }

src/server/lib/cookie.js

@@ -1,12 +1,14 @@
-// Function to set cookies server side
-//
-// Credit to @huv1k and @jshttp contributors for the code which this is based on (MIT License).
-// * https://github.com/jshttp/cookie/blob/master/index.js
-// * https://github.com/zeit/next.js/blob/master/examples/api-routes-middleware/utils/cookies.js
-//
-// As only partial functionlity is required, only the code we need has been incorporated here
-// (with fixes for specific issues) to keep dependancy size down.
-const set = (res, name, value, options = {}) => {
+/**
+ * Function to set cookies server side
+ *
+ * Credit to @huv1k and @jshttp contributors for the code which this is based on (MIT License).
+ * * https://github.com/jshttp/cookie/blob/master/index.js
+ * * https://github.com/zeit/next.js/blob/master/examples/api-routes-middleware/utils/cookies.js
+ *
+ * As only partial functionlity is required, only the code we need has been incorporated here
+ * (with fixes for specific issues) to keep dependancy size down.
+ */
+export function set (res, name, value, options = {}) {
   const stringValue = typeof value === 'object' ? 'j:' + JSON.stringify(value) : String(value)
 
   if ('maxAge' in options) {
@@ -99,6 +101,56 @@ function _serialize (name, val, options) {
   return str
 }
 
-export default {
-  set
+/**
+ * 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) {
+  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
+      }
+    }
+  }
 }

src/server/lib/create-secret.js

@@ -0,0 +1,13 @@
+import { createHash } from 'crypto'
+
+/**
+ * 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 }) {
+  return userOptions.secret || createHash('sha256').update(JSON.stringify({
+    baseUrl, basePath, ...userOptions
+  })).digest('hex')
+}

src/server/lib/csrf-token-handler.js

@@ -0,0 +1,42 @@
+import { createHash, randomBytes } from 'crypto'
+import * as cookie from './cookie'
+
+/**
+ * Ensure CSRF Token cookie is set for any subsequent requests.
+ * Used as part of the strateigy for mitigation for CSRF tokens.
+ *
+ * Creates a cookie like 'next-auth.csrf-token' with the value 'token|hash',
+ * where 'token' is the CSRF token and 'hash' is a hash made of the token and
+ * the secret, and the two values are joined by a pipe '|'. By storing the
+ * value and the hash of the value (with the secret used as a salt) we can
+ * verify the cookie was set by the server and not by a malicous attacker.
+ *
+ * For more details, see the following OWASP links:
+ * 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, res, cookies, secret) {
+  const { csrfToken: csrfTokenFromRequest } = req.body
+
+  let csrfTokenFromCookie
+  let csrfTokenVerified = false
+  if (req.cookies[cookies.csrfToken.name]) {
+    const [csrfTokenValue, csrfTokenHash] = req.cookies[cookies.csrfToken.name].split('|')
+    if (csrfTokenHash === createHash('sha256').update(`${csrfTokenValue}${secret}`).digest('hex')) {
+      // If hash matches then we trust the CSRF token value
+      csrfTokenFromCookie = csrfTokenValue
+
+      // If this is a POST request and the CSRF Token in the Post request matches
+      // the cookie we have already verified is one we have set, then token is verified!
+      if (req.method === 'POST' && csrfTokenFromCookie === csrfTokenFromRequest) { csrfTokenVerified = true }
+    }
+  }
+  if (!csrfTokenFromCookie) {
+    // If no csrfToken - 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.
+    csrfTokenFromCookie = randomBytes(32).toString('hex')
+    const newCsrfTokenCookie = `${csrfTokenFromCookie}|${createHash('sha256').update(`${csrfTokenFromCookie}${secret}`).digest('hex')}`
+    cookie.set(res, cookies.csrfToken.name, newCsrfTokenCookie, cookies.csrfToken.options)
+  }
+  return { csrfToken: csrfTokenFromCookie, csrfTokenVerified }
+}

src/server/lib/default-callbacks.js

@@ -9,19 +9,14 @@
  * requests to sign in and again when they activate the link in the sign in
  * email.
  *
- * @param  {object} profile  User profile (e.g. user id, name, email)
- * @param  {object} account  Account used to sign in (e.g. OAuth account)
- * @param  {object} metadata Provider specific metadata (e.g. OAuth Profile)
- * @return {boolean|object}  Return `true` (or a modified JWT) to allow sign in
- *                           Return `false` to deny access
+ * @param  {object} profile          User profile (e.g. user id, name, email)
+ * @param  {object} account          Account used to sign in (e.g. OAuth account)
+ * @param  {object} metadata         Provider specific metadata (e.g. OAuth Profile)
+ * @return {Promise<boolean|never>}  Return `true` (or a modified JWT) to allow sign in
+ *                                   Return `false` to deny access
  */
-const signIn = async (profile, account, metadata) => {
-  const isAllowedToSignIn = true
-  if (isAllowedToSignIn) {
-    return Promise.resolve(true)
-  } else {
-    return Promise.resolve(false)
-  }
+export async function signIn () {
+  return true
 }
 
 /**
@@ -31,12 +26,13 @@ const signIn = async (profile, account, metadata) => {
  *
  * @param  {string} url      URL provided as callback URL by the client
  * @param  {string} baseUrl  Default base URL of site (can be used as fallback)
- * @return {string}          URL the client will be redirect to
+ * @return {Promise<string>} URL the client will be redirect to
  */
-const redirect = async (url, baseUrl) => {
-  return url.startsWith(baseUrl)
-    ? Promise.resolve(url)
-    : Promise.resolve(baseUrl)
+export async function redirect (url, baseUrl) {
+  if (url.startsWith(baseUrl)) {
+    return url
+  }
+  return baseUrl
 }
 
 /**
@@ -45,31 +41,24 @@ const redirect = async (url, baseUrl) => {
  *
  * @param  {object} session  Session object
  * @param  {object} token    JSON Web Token (if enabled)
- * @return {object}          Session that will be returned to the client
+ * @return {Promise<object>} Session that will be returned to the client
  */
-const session = async (session, token) => {
-  return Promise.resolve(session)
+export async function session (session) {
+  return session
 }
 
 /**
  * This callback is called whenever a JSON Web Token is created / updated.
  * e.g. On sign in, `getSession()`, `useSession()`, `/api/auth/session` (etc)
  *
- * On initial sign in, the raw oAuthProfile is passed if the user is signing in
+ * On initial sign in, the raw OAuthProfile is passed if the user is signing in
  * with an OAuth provider. It is not avalible on subsequent calls. You can
  * take advantage of this to persist additional data you need to in the JWT.
  *
  * @param  {object} token         Decrypted JSON Web Token
  * @param  {object} oAuthProfile  OAuth profile - only available on sign in
- * @return {object}               JSON Web Token that will be saved
+ * @return {Promise<object>}      JSON Web Token that will be saved
  */
-const jwt = async (token, oAuthProfile) => {
-  return Promise.resolve(token)
-}
-
-export default {
-  signIn,
-  redirect,
-  session,
-  jwt
+export async function jwt (token) {
+  return token
 }

src/server/lib/default-events.js

@@ -0,0 +1,23 @@
+/** Event triggered on successful sign in */
+export async function signIn (message) {}
+
+/** Event triggered on sign out */
+export async function signOut (message) {}
+
+/** Event triggered on user creation */
+export async function createUser (message) {}
+
+/** Event triggered when a user object is updated */
+export async function updateUser (message) {}
+
+/** Event triggered when an account is linked to a user */
+export async function linkAccount (message) {}
+
+/** Event triggered when a session is active */
+export async function session (message) {}
+
+/**
+ * @TODO Event triggered when something goes wrong in an authentication flow
+ * This event may be fired multiple times when an error occurs
+ */
+export async function error (message) {}

src/server/lib/dispatch-event.js

@@ -1,6 +1,6 @@
 import logger from '../../lib/logger'
 
-export default async (event, message) => {
+export default async function dispatchEvent (event, message) {
   try {
     await event(message)
   } catch (e) {

src/server/lib/events.js

@@ -1,38 +0,0 @@
-const signIn = async (message) => {
-  // Event triggered on successful sign in
-}
-
-const signOut = async (message) => {
-  // Event triggered on sign out
-}
-
-const createUser = async (message) => {
-  // Event triggered on user creation
-}
-
-const updateUser = async (message) => {
-  // Event triggered when a user object is updated
-}
-
-const linkAccount = async (message) => {
-  // Event triggered when an account is linked to a user
-}
-
-const session = async (message) => {
-  // Event triggered when a session is active
-}
-
-const error = async (message) => {
-  // @TODO Event triggered when something goes wrong in an authentication flow
-  // This event may be fired multiple times when an error occurs
-}
-
-export default {
-  signIn,
-  signOut,
-  createUser,
-  updateUser,
-  linkAccount,
-  session,
-  error
-}

src/server/lib/extend-req.js

@@ -0,0 +1,35 @@
+/**
+ * Extends res.{end,json,send} with `done()`,
+ * and redirect to support sending url as json.
+ *
+ * When a response is complete, it will call the `done` method,
+ * so that the serverless function knows when it is
+ * safe to return and that no more data will be sent.
+ */
+export default function extendRes (req, res, done) {
+  const originalResEnd = res.end.bind(res)
+  res.end = (...args) => {
+    done()
+    return originalResEnd(...args)
+  }
+
+  const originalResJson = res.json.bind(res)
+  res.json = (...args) => {
+    done()
+    return originalResJson(...args)
+  }
+
+  const originalResSend = res.send.bind(res)
+  res.send = (...args) => {
+    done()
+    return originalResSend(...args)
+  }
+
+  res.redirect = (url) => {
+    if (req.body?.json === 'true') {
+      return res.json({ url })
+    }
+    res.status(302).setHeader('Location', url)
+    return res.end()
+  }
+}

src/server/lib/oauth/callback.js

@@ -1,50 +1,33 @@
-
-import { createHash } from 'crypto'
-import querystring from 'querystring'
-import jwtDecode from 'jwt-decode'
+import { decode as jwtDecode } from 'jsonwebtoken'
 import oAuthClient from './client'
 import logger from '../../../lib/logger'
+import { OAuthCallbackError } from '../../../lib/errors'
 
-// @TODO Refactor monkey patching in _getOAuthAccessToken() and _get()
-// These methods have been forked from `node-oauth` to fix bugs; it may make
-// sense to migrate all the methods we need from node-oauth to nexth-auth (with
-// appropriate credit) to make it easier to maintain and address issues as they
-// come up, as the node-oauth package does not seem to be actively maintained.
-
-// @TODO Refactor to use promises and not callbacks
-// @TODO Refactor to use jsonwebtoken instead of jwt-decode & remove dependancy
-export default async (req, provider, csrfToken, callback) => {
-  // The "user" object is specific to apple provider and is provided on first sign in
-  // e.g. {"name":{"firstName":"Johnny","lastName":"Appleseed"},"email":"johnny.appleseed@nextauth.com"}
-  let { oauth_token, oauth_verifier, code, user, state } = req.query // eslint-disable-line camelcase
+export default async function oAuthCallback (req) {
+  const { provider, pkce } = req.options
   const client = oAuthClient(provider)
 
-  if (provider.version && provider.version.startsWith('2.')) {
-    // For OAuth 2.0 flows, check state returned and matches expected value
-    // (a hash of the NextAuth.js CSRF token).
-    //
-    // This check can be disabled for providers that do not support it by
-    // setting `state: false` as a option on the provider (defaults to true).
-    if (!Object.prototype.hasOwnProperty.call(provider, 'state') || provider.state === true) {
-      const expectedState = createHash('sha256').update(csrfToken).digest('hex')
-      if (state !== expectedState) {
-        return callback(new Error('Invalid state returned from oAuth provider'))
-      }
-    }
+  if (provider.version?.startsWith('2.')) {
+    // The "user" object is specific to the Apple provider and is provided on first sign in
+    // e.g. {"name":{"firstName":"Johnny","lastName":"Appleseed"},"email":"johnny.appleseed@nextauth.com"}
+    let { code, user } = req.query // eslint-disable-line camelcase
 
     if (req.method === 'POST') {
       try {
         const body = JSON.parse(JSON.stringify(req.body))
-        if (body.error) { throw new Error(body.error) }
+        if (body.error) {
+          throw new Error(body.error)
+        }
 
         code = body.code
         user = body.user != null ? JSON.parse(body.user) : null
-      } catch (e) {
-        logger.error('OAUTH_CALLBACK_HANDLER_ERROR', e, req.body, provider.id, code)
-        return callback()
+      } catch (error) {
+        logger.error('OAUTH_CALLBACK_HANDLER_ERROR', error, req.body, provider.id, code)
+        throw error
       }
     }
 
+    // REVIEW: Is this used by any of the providers?
     // Pass authToken in header by default (unless 'useAuthTokenHeader: false' is set)
     if (Object.prototype.hasOwnProperty.call(provider, 'useAuthTokenHeader')) {
       client.useAuthorizationHeaderforGET(provider.useAuthTokenHeader)
@@ -52,78 +35,56 @@ export default async (req, provider, csrfToken, callback) => {
       client.useAuthorizationHeaderforGET(true)
     }
 
-    // Use custom getOAuthAccessToken() method for oAuth2 flows
-    client.getOAuthAccessToken = _getOAuthAccessToken
-
-    await client.getOAuthAccessToken(
-      code,
-      provider,
-      (error, accessToken, refreshToken, results) => {
-        if (error || results.error) {
-          logger.error('OAUTH_GET_ACCESS_TOKEN_ERROR', error, results, provider.id, code)
-          return callback(error || results.error)
+    try {
+      const { accessToken, refreshToken, results } = await client.getOAuthAccessToken(code, provider, pkce.code_verifier)
+      const tokens = { accessToken, refreshToken, idToken: results.id_token }
+      let profileData
+      if (provider.idToken) {
+        // If we don't have an ID Token most likely the user hit a cancel
+        // button when signing in (or the provider is misconfigured).
+        //
+        // Unfortunately, we can't tell which, so we can't treat it as an
+        // error, so instead we just returning nothing, which will cause the
+        // user to be redirected back to the sign in page.
+        if (!results?.id_token) {
+          throw new OAuthCallbackError()
         }
 
-        if (provider.idToken) {
-          // If we don't have an ID Token most likely the user hit a cancel
-          // button when signing in (or the provider is misconfigured).
-          //
-          // Unfortunately, we can't tell which, so we can't treat it as an
-          // error, so instead we just returning nothing, which will cause the
-          // user to be redirected back to the sign in page.
-          if (!results || !results.id_token) {
-            return callback()
-          }
-
-          // Support services that use OpenID ID Tokens to encode profile data
-          _decodeToken(
-            provider,
-            accessToken,
-            refreshToken,
-            results.id_token,
-            async (error, profileData) => {
-              const { profile, account, OAuthProfile } = await _getProfile(error, profileData, accessToken, refreshToken, provider, user)
-              callback(error, profile, account, OAuthProfile)
-            }
-          )
-        } else {
-          // Use custom get() method for oAuth2 flows
-          client.get = _get
-
-          client.get(
-            provider,
-            accessToken,
-            async (error, profileData) => {
-              const { profile, account, OAuthProfile } = await _getProfile(error, profileData, accessToken, refreshToken, provider)
-              callback(error, profile, account, OAuthProfile)
-            }
-          )
-        }
+        // Support services that use OpenID ID Tokens to encode profile data
+        profileData = decodeIdToken(results.id_token)
+      } else {
+        profileData = await client.get(provider, accessToken, results)
       }
-    )
-  } else {
-    // Handle oAuth v1.x
-    await client.getOAuthAccessToken(
-      oauth_token,
-      null,
-      oauth_verifier,
-      (error, accessToken, refreshToken, results) => {
-        // @TODO Handle error
-        if (error || results.error) {
-          logger.error('OAUTH_V1_GET_ACCESS_TOKEN_ERROR', error, results)
-        }
 
-        client.get(
-          provider.profileUrl,
-          accessToken,
-          refreshToken,
-          async (error, profileData) => {
-            const { profile, account, OAuthProfile } = await _getProfile(error, profileData, accessToken, refreshToken, provider)
-            callback(error, profile, account, OAuthProfile)
-          }
-        )
-      }
+      return _getProfile({ profileData, provider, tokens, user })
+    } catch (error) {
+      logger.error('OAUTH_GET_ACCESS_TOKEN_ERROR', error, provider.id, code)
+      throw error
+    }
+  }
+
+  try {
+    // Handle OAuth v1.x
+    const {
+      oauth_token: oauthToken, oauth_verifier: oauthVerifier
+    } = req.query
+    const { accessToken, refreshToken, results } = await client.getOAuthAccessToken(oauthToken, null, oauthVerifier)
+    const profileData = await client.get(
+      provider.profileUrl,
+      accessToken,
+      refreshToken
     )
+
+    const tokens = {
+      accessToken, refreshToken, idToken: results.id_token
+    }
+
+    return _getProfile({
+      profileData, tokens, provider
+    })
+  } catch (error) {
+    logger.error('OAUTH_V1_GET_ACCESS_TOKEN_ERROR', error)
+    throw error
   }
 }
 
@@ -131,25 +92,41 @@ export default async (req, provider, csrfToken, callback) => {
  * //6/30/2020 @geraldnolan added userData parameter to attach additional data to the profileData object
  * Returns profile, raw profile and auth provider details
  */
-async function _getProfile (error, profileData, accessToken, refreshToken, provider, userData) {
-  // @TODO Handle error
-  if (error) {
-    logger.error('OAUTH_GET_PROFILE_ERROR', error)
-  }
-
-  let profile = {}
+async function _getProfile ({
+  profileData, tokens: { accessToken, refreshToken, idToken }, provider, user
+}) {
   try {
     // Convert profileData into an object if it's a string
-    if (typeof profileData === 'string' || profileData instanceof String) { profileData = JSON.parse(profileData) }
+    if (typeof profileData === 'string' || profileData instanceof String) {
+      profileData = JSON.parse(profileData)
+    }
 
     // If a user object is supplied (e.g. Apple provider) add it to the profile object
-    if (userData != null) {
-      profileData.user = userData
+    if (user != null) {
+      profileData.user = user
     }
 
+    profileData.idToken = idToken
+
     logger.debug('PROFILE_DATA', profileData)
 
-    profile = await provider.profile(profileData)
+    const profile = await provider.profile(profileData)
+    // Return profile, raw profile and auth provider details
+    return {
+      profile: {
+        ...profile,
+        email: profile.email?.toLowerCase() ?? null
+      },
+      account: {
+        provider: provider.id,
+        type: provider.type,
+        id: profile.id,
+        refreshToken,
+        accessToken,
+        accessTokenExpires: null
+      },
+      OAuthProfile: profileData
+    }
   } catch (exception) {
     // If we didn't get a response either there was a problem with the provider
     // response *or* the user cancelled the action with the provider.
@@ -165,111 +142,11 @@ async function _getProfile (error, profileData, accessToken, refreshToken, provi
       OAuthProfile: profileData
     }
   }
-
-  // Return profile, raw profile and auth provider details
-  return {
-    profile: {
-      name: profile.name,
-      email: profile.email ? profile.email.toLowerCase() : null,
-      image: profile.image
-    },
-    account: {
-      provider: provider.id,
-      type: provider.type,
-      id: profile.id,
-      refreshToken,
-      accessToken,
-      accessTokenExpires: null
-    },
-    OAuthProfile: profileData
-  }
 }
 
-// Ported from https://github.com/ciaranj/node-oauth/blob/a7f8a1e21c362eb4ed2039431fb9ac2ae749f26a/lib/oauth2.js
-async function _getOAuthAccessToken (code, provider, callback) {
-  const url = provider.accessTokenUrl
-  const setGetAccessTokenAuthHeader = (provider.setGetAccessTokenAuthHeader !== null) ? provider.setGetAccessTokenAuthHeader : true
-  const params = { ...provider.params } || {}
-  const headers = { ...provider.headers } || {}
-  const codeParam = (params.grant_type === 'refresh_token') ? 'refresh_token' : 'code'
-
-  if (!params[codeParam]) { params[codeParam] = code }
-
-  if (!params.client_id) { params.client_id = provider.clientId }
-
-  if (!params.client_secret) {
-    // For some providers it useful to be able to generate the secret on the fly
-    // e.g. For Sign in With Apple a JWT token using the properties in clientSecret
-    if (provider.clientSecretCallback) {
-      params.client_secret = await provider.clientSecretCallback(provider.clientSecret)
-    } else {
-      params.client_secret = provider.clientSecret
-    }
+function decodeIdToken (idToken) {
+  if (!idToken) {
+    throw new OAuthCallbackError('Missing JWT ID Token')
   }
-
-  if (!params.redirect_uri) { params.redirect_uri = provider.callbackUrl }
-
-  if (!headers['Content-Type']) { headers['Content-Type'] = 'application/x-www-form-urlencoded' }
-
-  // Added as a fix to accomodate change in Twitch oAuth API
-  if (!headers['Client-ID']) { headers['Client-ID'] = provider.clientId }
-
-  // Okta errors when this is set. Maybe there are other Providers that also wont like this.
-  if (setGetAccessTokenAuthHeader) {
-    if (!headers.Authorization) { headers.Authorization = `Bearer ${code}` }
-  }
-
-  const postData = querystring.stringify(params)
-
-  this._request(
-    'POST',
-    url,
-    headers,
-    postData,
-    null,
-    (error, data, response) => {
-      if (error) {
-        logger.error('OAUTH_GET_ACCESS_TOKEN_ERROR', error, data, response)
-        return callback(error)
-      }
-
-      let results
-      try {
-        // As of http://tools.ietf.org/html/draft-ietf-oauth-v2-07
-        // responses should be in JSON
-        results = JSON.parse(data)
-      } catch (e) {
-        // However both Facebook + Github currently use rev05 of the spec  and neither
-        // seem to specify a content-type correctly in their response headers. :(
-        // Clients of these services suffer a minor performance cost.
-        results = querystring.parse(data)
-      }
-      const accessToken = results.access_token
-      const refreshToken = results.refresh_token
-      callback(null, accessToken, refreshToken, results)
-    }
-  )
-}
-
-// Ported from https://github.com/ciaranj/node-oauth/blob/a7f8a1e21c362eb4ed2039431fb9ac2ae749f26a/lib/oauth2.js
-function _get (provider, accessToken, callback) {
-  const url = provider.profileUrl
-  const headers = provider.headers || {}
-
-  if (this._useAuthorizationHeaderForGET) {
-    headers.Authorization = this.buildAuthHeader(accessToken)
-
-    // This line is required for Twitch
-    headers['Client-ID'] = provider.clientId
-    accessToken = null
-  }
-
-  this._request('GET', url, headers, null, accessToken, callback)
-}
-
-function _decodeToken (provider, accessToken, refreshToken, idToken, callback) {
-  if (!idToken) { throw new Error('Missing JWT ID Token', provider, idToken) }
-  const decodedToken = jwtDecode(idToken)
-  const profileData = JSON.stringify(decodedToken)
-  callback(null, profileData, accessToken, refreshToken, provider)
+  return jwtDecode(idToken, { json: true })
 }

src/server/lib/oauth/client.js

@@ -1,31 +1,230 @@
-// @TODO Refactor to remove dependancy on 'oauth' package
-// It is already quite monkey patched, we don't use all the features and and it
-// would be easier to maintain if all the code was native to next-auth.
 import { OAuth, OAuth2 } from 'oauth'
+import querystring from 'querystring'
+import logger from '../../../lib/logger'
+import { sign as jwtSign } from 'jsonwebtoken'
 
-export default (provider) => {
-  if (provider.version && provider.version.startsWith('2.')) {
-    // Handle oAuth v2.x
-    const basePath = new URL(provider.authorizationUrl).origin
-    const authorizePath = new URL(provider.authorizationUrl).pathname
+/**
+ * @TODO Refactor to remove dependancy on 'oauth' package
+ * It is already quite monkey patched, we don't use all the features and and it
+ * would be easier to maintain if all the code was native to next-auth.
+ */
+export default function oAuthClient (provider) {
+  if (provider.version?.startsWith('2.')) {
+    // Handle OAuth v2.x
+    const authorizationUrl = new URL(provider.authorizationUrl)
+    const basePath = authorizationUrl.origin
+    const authorizePath = authorizationUrl.pathname
     const accessTokenPath = new URL(provider.accessTokenUrl).pathname
-    return new OAuth2(
+    const oauth2Client = new OAuth2(
       provider.clientId,
       provider.clientSecret,
       basePath,
       authorizePath,
       accessTokenPath,
-      provider.headers)
-  } else {
-    // Handle oAuth v1.x
-    return new OAuth(
-      provider.requestTokenUrl,
-      provider.accessTokenUrl,
-      provider.clientId,
-      provider.clientSecret,
-      (provider.version || '1.0'),
-      provider.callbackUrl,
-      (provider.encoding || 'HMAC-SHA1')
+      provider.headers
     )
+    oauth2Client.getOAuthAccessToken = getOAuth2AccessToken
+    oauth2Client.get = getOAuth2
+    return oauth2Client
   }
+  // Handle OAuth v1.x
+  const oauth1Client = new OAuth(
+    provider.requestTokenUrl,
+    provider.accessTokenUrl,
+    provider.clientId,
+    provider.clientSecret,
+    provider.version || '1.0',
+    provider.callbackUrl,
+    provider.encoding || 'HMAC-SHA1'
+  )
+
+  // Promisify get() and getOAuth2AccessToken() for OAuth1
+  const originalGet = oauth1Client.get
+  oauth1Client.get = (...args) => {
+    return new Promise((resolve, reject) => {
+      originalGet(...args, (error, result) => {
+        if (error) {
+          return reject(error)
+        }
+        resolve(result)
+      })
+    })
+  }
+  const originalGetOAuth1AccessToken = oauth1Client.getOAuthAccessToken
+  oauth1Client.getOAuthAccessToken = (...args) => {
+    return new Promise((resolve, reject) => {
+      originalGetOAuth1AccessToken(...args, (error, accessToken, refreshToken, results) => {
+        if (error) {
+          return reject(error)
+        }
+        resolve({ accessToken, refreshToken, results })
+      })
+    })
+  }
+
+  const originalGetOAuthRequestToken = oauth1Client.getOAuthRequestToken
+  oauth1Client.getOAuthRequestToken = (...args) => {
+    return new Promise((resolve, reject) => {
+      originalGetOAuthRequestToken(...args, (error, oauthToken) => {
+        if (error) {
+          return reject(error)
+        }
+        resolve(oauthToken)
+      })
+    })
+  }
+  return oauth1Client
+}
+
+/**
+ * @TODO Refactor monkey patching in OAuth2.getOAuthAccessToken() and OAuth2.get()
+ * These methods have been forked from `node-oauth` to fix bugs; it may make
+ * sense to migrate all the methods we need from node-oauth to nexth-auth (with
+ * appropriate credit) to make it easier to maintain and address issues as they
+ * come up, as the node-oauth package does not seem to be actively maintained.
+ */
+
+/**
+ * Ported from https://github.com/ciaranj/node-oauth/blob/a7f8a1e21c362eb4ed2039431fb9ac2ae749f26a/lib/oauth2.js
+ */
+async function getOAuth2AccessToken (code, provider, codeVerifier) {
+  const url = provider.accessTokenUrl
+  const params = { ...provider.params }
+  const headers = { ...provider.headers }
+  const codeParam = (params.grant_type === 'refresh_token') ? 'refresh_token' : 'code'
+
+  if (!params[codeParam]) { params[codeParam] = code }
+
+  if (!params.client_id) { params.client_id = provider.clientId }
+
+  // For Apple the client secret must be generated on-the-fly.
+  // Using the properties in clientSecret to create a JWT.
+  if (provider.id === 'apple' && typeof provider.clientSecret === 'object') {
+    const { keyId, teamId, privateKey } = provider.clientSecret
+    const clientSecret = jwtSign({
+      iss: teamId,
+      iat: Math.floor(Date.now() / 1000),
+      exp: Math.floor(Date.now() / 1000) + (86400 * 180), // 6 months
+      aud: 'https://appleid.apple.com',
+      sub: provider.clientId
+    },
+    // Automatically convert \\n into \n if found in private key. If the key
+    // is passed in an environment variable \n can get escaped as \\n
+    privateKey.replace(/\\n/g, '\n'),
+    { algorithm: 'ES256', keyid: keyId }
+    )
+    params.client_secret = clientSecret
+  } else {
+    params.client_secret = provider.clientSecret
+  }
+
+  if (!params.redirect_uri) { params.redirect_uri = provider.callbackUrl }
+
+  if (!headers['Content-Type']) { headers['Content-Type'] = 'application/x-www-form-urlencoded' }
+  // Added as a fix to accomodate change in Twitch OAuth API
+  if (!headers['Client-ID']) { headers['Client-ID'] = provider.clientId }
+  // Added as a fix for Reddit Authentication
+  if (provider.id === 'reddit') {
+    headers.Authorization = 'Basic ' + Buffer.from((provider.clientId + ':' + provider.clientSecret)).toString('base64')
+  }
+
+  if ((provider.id === 'okta' || provider.id === 'identity-server4') && !headers.Authorization) {
+    headers.Authorization = `Bearer ${code}`
+  }
+
+  if (provider.protection === 'pkce') {
+    params.code_verifier = codeVerifier
+  }
+
+  const postData = querystring.stringify(params)
+
+  return new Promise((resolve, reject) => {
+    this._request(
+      'POST',
+      url,
+      headers,
+      postData,
+      null,
+      (error, data, response) => {
+        if (error) {
+          logger.error('OAUTH_GET_ACCESS_TOKEN_ERROR', error, data, response)
+          return reject(error)
+        }
+
+        let results
+        try {
+          // As of http://tools.ietf.org/html/draft-ietf-oauth-v2-07
+          // responses should be in JSON
+          results = JSON.parse(data)
+        } catch (e) {
+          // However both Facebook + Github currently use rev05 of the spec  and neither
+          // seem to specify a content-type correctly in their response headers. :(
+          // Clients of these services suffer a minor performance cost.
+          results = querystring.parse(data)
+        }
+        let accessToken = results.access_token
+        if (provider.id === 'slack') {
+          accessToken = results.authed_user.access_token
+        }
+        const refreshToken = results.refresh_token
+        resolve({ accessToken, refreshToken, results })
+      }
+    )
+  })
+}
+
+/**
+ * Ported from https://github.com/ciaranj/node-oauth/blob/a7f8a1e21c362eb4ed2039431fb9ac2ae749f26a/lib/oauth2.js
+ *
+ * 18/08/2020 @robertcraigie added results parameter to pass data to an optional request preparer.
+ * e.g. see providers/bungie
+ */
+async function getOAuth2 (provider, accessToken, results) {
+  let url = provider.profileUrl
+  const headers = { ...provider.headers }
+
+  if (this._useAuthorizationHeaderForGET) {
+    headers.Authorization = this.buildAuthHeader(accessToken)
+
+    // Mail.ru & vk.com require 'access_token' as URL request parameter
+    if (['mailru', 'vk'].includes(provider.id)) {
+      const safeAccessTokenURL = new URL(url)
+      safeAccessTokenURL.searchParams.append('access_token', accessToken)
+      url = safeAccessTokenURL.href
+    }
+
+    // This line is required for Twitch
+    if (provider.id === 'twitch') {
+      headers['Client-ID'] = provider.clientId
+    }
+    accessToken = null
+  }
+
+  if (provider.id === 'bungie') {
+    url = prepareProfileUrl({ provider, url, results })
+  }
+
+  return new Promise((resolve, reject) => {
+    this._request('GET', url, headers, null, accessToken, (error, profileData) => {
+      if (error) {
+        return reject(error)
+      }
+      resolve(profileData)
+    })
+  })
+}
+
+/** Bungie needs special handling */
+function prepareProfileUrl ({ provider, url, results }) {
+  if (!results.membership_id) {
+    // internal error
+    // @TODO: handle better
+    throw new Error('Expected membership_id to be passed.')
+  }
+
+  if (!provider.headers?.['X-API-Key']) {
+    throw new Error('The Bungie provider requires the X-API-Key option to be present in "headers".')
+  }
+
+  return url.replace('{membershipId}', results.membership_id)
 }

src/server/lib/oauth/pkce-handler.js

@@ -0,0 +1,82 @@
+import pkceChallenge from 'pkce-challenge'
+import * as cookie from '../cookie'
+import jwt from '../../../lib/jwt'
+import logger from '../../../lib/logger'
+import { OAuthCallbackError } from '../../../lib/errors'
+
+const PKCE_LENGTH = 64
+const PKCE_CODE_CHALLENGE_METHOD = 'S256' // can be 'plain', not recommended https://tools.ietf.org/html/rfc7636#section-4.2
+const PKCE_MAX_AGE = 60 * 15 // 15 minutes in seconds
+
+/** Adds `code_verifier` to `req.options.pkce`, and removes the corresponding cookie */
+export async function handleCallback (req, res) {
+  const { cookies, provider, baseUrl, basePath } = req.options
+  try {
+    if (provider.protection !== 'pkce') { // Provider does not support PKCE, nothing to do.
+      return
+    }
+
+    if (!(cookies.pkceCodeVerifier.name in req.cookies)) {
+      throw new OAuthCallbackError('The code_verifier cookie was not found.')
+    }
+    const pkce = await jwt.decode({
+      ...req.options.jwt,
+      token: req.cookies[cookies.pkceCodeVerifier.name],
+      maxAge: PKCE_MAX_AGE,
+      encryption: true
+    })
+    req.options.pkce = pkce
+    logger.debug('OAUTH_CALLBACK_PROTECTION', 'Read PKCE verifier from cookie', {
+      code_verifier: pkce.code_verifier,
+      pkceLength: PKCE_LENGTH,
+      method: PKCE_CODE_CHALLENGE_METHOD
+    })
+    cookie.set(res, cookies.pkceCodeVerifier.name, null, { maxAge: 0 }) // remove PKCE after it has been used
+  } catch (error) {
+    logger.error('CALLBACK_OAUTH_ERROR', error)
+    return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
+  }
+}
+
+/** Adds `code_challenge` and `code_challenge_method` to `req.options.pkce`. */
+export async function handleSignin (req, res) {
+  const { cookies, provider, baseUrl, basePath } = req.options
+  try {
+    if (provider.protection !== 'pkce') { // Provider does not support PKCE, nothing to do.
+      return
+    }
+    // Started login flow, add generated pkce to req.options and (encrypted) code_verifier to a cookie
+    const pkce = pkceChallenge(PKCE_LENGTH)
+    logger.debug('OAUTH_SIGNIN_PROTECTION', 'Created PKCE challenge/verifier', {
+      ...pkce,
+      pkceLength: PKCE_LENGTH,
+      method: PKCE_CODE_CHALLENGE_METHOD
+    })
+
+    provider.authorizationParams = {
+      ...provider.authorizationParams,
+      code_challenge: pkce.code_challenge,
+      code_challenge_method: PKCE_CODE_CHALLENGE_METHOD
+    }
+
+    const encryptedCodeVerifier = await jwt.encode({
+      ...req.options.jwt,
+      maxAge: PKCE_MAX_AGE,
+      token: { code_verifier: pkce.code_verifier },
+      encryption: true
+    })
+
+    const cookieExpires = new Date()
+    cookieExpires.setTime(cookieExpires.getTime() + (PKCE_MAX_AGE * 1000))
+    cookie.set(res, cookies.pkceCodeVerifier.name, encryptedCodeVerifier, {
+      expires: cookieExpires.toISOString(),
+      ...cookies.pkceCodeVerifier.options
+    })
+    logger.debug('OAUTH_SIGNIN_PROTECTION', 'Created PKCE code_verifier saved in cookie')
+  } catch (error) {
+    logger.error('SIGNIN_OAUTH_ERROR', error)
+    return res.redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
+  }
+}
+
+export default { handleSignin, handleCallback }

src/server/lib/oauth/state-handler.js

@@ -0,0 +1,64 @@
+import { createHash } from 'crypto'
+import logger from '../../../lib/logger'
+import { OAuthCallbackError } from '../../../lib/errors'
+
+/**
+ * For OAuth 2.0 flows, if the provider supports state,
+ * check if state matches the one sent on signin
+ * (a hash of the NextAuth.js CSRF token).
+ */
+export async function handleCallback (req, res) {
+  const { csrfToken, provider, baseUrl, basePath } = req.options
+  try {
+    if (provider.protection !== 'state') { // Provider does not support state, nothing to do.
+      return
+    }
+
+    const { state } = req.query
+    const expectedState = createHash('sha256').update(csrfToken).digest('hex')
+
+    logger.debug(
+      'OAUTH_CALLBACK_PROTECTION',
+      'Comparing received and expected state',
+      { state, expectedState }
+    )
+    if (state !== expectedState) {
+      throw new OAuthCallbackError('Invalid state returned from OAuth provider')
+    }
+  } catch (error) {
+    logger.error('STATE_ERROR', error)
+    return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
+  }
+}
+
+/** Adds CSRF token to the authorizationParams. */
+export async function handleSignin (req, res) {
+  const { provider, baseUrl, basePath, csrfToken } = req.options
+  try {
+    if (provider.protection !== 'state') { // Provider does not support state, nothing to do.
+      return
+    }
+
+    if ('state' in provider) {
+      logger.warn(
+        'STATE_OPTION_DEPRECATION',
+        'The `state` provider option is being replaced with `protection`. See the docs.'
+      )
+    }
+
+    // A hash of the NextAuth.js CSRF token is used as the state
+    const state = createHash('sha256').update(csrfToken).digest('hex')
+
+    provider.authorizationParams = { ...provider.authorizationParams, state }
+    logger.debug(
+      'OAUTH_CALLBACK_PROTECTION',
+      'Added state to authorization params',
+      { state }
+    )
+  } catch (error) {
+    logger.error('SIGNIN_OAUTH_ERROR', error)
+    return res.redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
+  }
+}
+
+export default { handleSignin, handleCallback }

src/server/lib/providers.js

@@ -1,14 +1,8 @@
-export default (_providers, baseUrl, basePath) => {
-  const providers = {}
-
-  _providers.forEach(provider => {
-    const providerId = provider.id
-    providers[providerId] = {
-      ...provider,
-      signinUrl: `${baseUrl}${basePath}/signin/${providerId}`,
-      callbackUrl: `${baseUrl}${basePath}/callback/${providerId}`
-    }
-  })
-
-  return providers
+/** Adds `signinUrl` and `callbackUrl` to each provider. */
+export default function parseProviders ({ providers = [], baseUrl, basePath }) {
+  return providers.map((provider) => ({
+    ...provider,
+    signinUrl: `${baseUrl}${basePath}/signin/${provider.id}`,
+    callbackUrl: `${baseUrl}${basePath}/callback/${provider.id}`
+  }))
 }

src/server/lib/signin/email.js

@@ -1,6 +1,6 @@
 import { randomBytes } from 'crypto'
 
-export default async (email, provider, options) => {
+export default async function email (email, provider, options) {
   try {
     const { baseUrl, basePath, adapter } = options
 
@@ -10,7 +10,7 @@ export default async (email, provider, options) => {
     const secret = provider.secret || options.secret
 
     // Generate token
-    const token = randomBytes(32).toString('hex')
+    const token = provider.generateVerificationToken?.() ?? randomBytes(32).toString('hex')
 
     // Send email with link containing token (the unhashed version)
     const url = `${baseUrl}${basePath}/callback/${encodeURIComponent(provider.id)}?email=${encodeURIComponent(email)}&token=${encodeURIComponent(token)}`

src/server/lib/signin/oauth.js

@@ -1,24 +1,24 @@
 import oAuthClient from '../oauth/client'
-import { createHash } from 'crypto'
 import logger from '../../../lib/logger'
 
-export default (provider, csrfToken, callback, authParams) => {
-  const { callbackUrl } = provider
+export default async function getAuthorizationUrl (req) {
+  const { provider } = req.options
+
   const client = oAuthClient(provider)
-  if (provider.version && provider.version.startsWith('2.')) {
-    // Handle oAuth v2.x
+  if (provider.version?.startsWith('2.')) {
+    delete req.query?.nextauth
+    // Handle OAuth v2.x
     let url = client.getAuthorizeUrl({
-      ...authParams,
+      ...provider.authorizationParams,
+      ...req.query,
       redirect_uri: provider.callbackUrl,
-      scope: provider.scope,
-      // A hash of the NextAuth.js CSRF token is used as the state
-      state: createHash('sha256').update(csrfToken).digest('hex')
+      scope: provider.scope
     })
 
     // If the authorizationUrl specified in the config has query parameters on it
     // make sure they are included in the URL we return.
     //
-    // This is a fix for an open issue with the oAuthClient library we are using
+    // This is a fix for an open issue with the OAuthClient library we are using
     // which inadvertantly strips them.
     //
     // https://github.com/ciaranj/node-oauth/pull/193
@@ -28,15 +28,17 @@ export default (provider, csrfToken, callback, authParams) => {
       url = url.replace(baseUrl, provider.authorizationUrl + '&')
     }
 
-    callback(null, url)
-  } else {
-    // Handle oAuth v1.x
-    client.getOAuthRequestToken((error, oAuthToken) => {
-      if (error) {
-        logger.error('GET_AUTHORISATION_URL_ERROR', error)
-      }
-      const url = `${provider.authorizationUrl}?oauth_token=${oAuthToken}`
-      callback(error, url)
-    }, callbackUrl)
+    logger.debug('GET_AUTHORIZATION_URL', url)
+    return url
+  }
+
+  try {
+    const oAuthToken = await client.getOAuthRequestToken(provider.callbackUrl)
+    const url = `${provider.authorizationUrl}?oauth_token=${oAuthToken}`
+    logger.debug('GET_AUTHORIZATION_URL', url)
+    return url
+  } catch (error) {
+    logger.error('GET_AUTHORIZATION_URL_ERROR', error)
+    throw error
   }
 }

src/server/pages/error.js

@@ -1,72 +1,58 @@
 import { h } from 'preact' // eslint-disable-line no-unused-vars
 import render from 'preact-render-to-string'
 
-export default ({ baseUrl, basePath, error, res }) => {
+/** Renders an error page. */
+export default function error ({ baseUrl, basePath, error, res }) {
   const signinPageUrl = `${baseUrl}${basePath}/signin`
 
-  let statusCode = 200
-  let heading = <h1>Error</h1>
-  let message = <p><a className='site' href={baseUrl}>{baseUrl.replace(/^https?:\/\//, '')}</a></p>
-
-  switch (error) {
-    case 'Signin':
-    case 'OAuthSignin':
-    case 'OAuthCallback':
-    case 'OAuthCreateAccount':
-    case 'EmailCreateAccount':
-    case 'Callback':
-    case 'OAuthAccountNotLinked':
-    case 'EmailSignin':
-    case 'CredentialsSignin':
-      // These messages are displayed in line on the sign in page
-      res.status(302).setHeader('Location', `${signinPageUrl}?error=${error}`)
-      res.end()
-      return false
-    case 'Configuration':
-      statusCode = 500
-      heading = <h1>Server error</h1>
-      message =
+  const errors = {
+    default: {
+      statusCode: 200,
+      heading: 'Error',
+      message: <p><a className='site' href={baseUrl}>{baseUrl.replace(/^https?:\/\//, '')}</a></p>
+    },
+    configuration: {
+      statusCode: 500,
+      heading: 'Server error',
+      message: (
         <div>
-          <div className='message'>
-            <p>There is a problem with the server configuration.</p>
-            <p>Check the server logs for more information.</p>
-          </div>
+          <p>There is a problem with the server configuration.</p>
+          <p>Check the server logs for more information.</p>
         </div>
-      break
-    case 'AccessDenied':
-      statusCode = 403
-      heading = <h1>Access Denied</h1>
-      message =
+      )
+    },
+    accessdenied: {
+      statusCode: 403,
+      heading: 'Access Denied',
+      message: (
         <div>
-          <div className='message'>
-            <p>You do not have permission to sign in.</p>
-            <p><a className='button' href={signinPageUrl}>Sign in</a></p>
-          </div>
-        </div>
-      break
-    case 'Verification':
-      // @TODO Check if user is signed in already with the same email address.
-      // If they are, no need to display this message, can just direct to callbackUrl
-      statusCode = 403
-      heading = <h1>Unable to sign in</h1>
-      message =
-        <div>
-          <div className='message'>
-            <p>The sign in link is no longer valid.</p>
-            <p>It may have be used already or it may have expired.</p>
-          </div>
+          <p>You do not have permission to sign in.</p>
           <p><a className='button' href={signinPageUrl}>Sign in</a></p>
         </div>
-      break
-    default:
+      )
+    },
+    verification: {
+      statusCode: 403,
+      heading: 'Unable to sign in',
+      message: (
+        <div>
+          <p>The sign in link is no longer valid.</p>
+          <p>It may have be used already or it may have expired.</p>
+        </div>
+      ),
+      signin: <p><a className='button' href={signinPageUrl}>Sign in</a></p>
+    }
   }
 
+  const { statusCode, heading, message, signin } = errors[error.toLowerCase()] || errors.default
+
   res.status(statusCode)
 
   return render(
     <div className='error'>
-      {heading}
-      {message}
+      <h1>{heading}</h1>
+      <div className='message'>{message}</div>
+      {signin}
     </div>
   )
 }

src/server/pages/index.js

@@ -4,32 +4,19 @@ import verifyRequest from './verify-request'
 import error from './error'
 import css from '../../css'
 
-function render (req, res, page, props, done) {
-  let html = ''
-  switch (page) {
-    case 'signin':
-      html = signin({ ...props, req })
-      break
-    case 'signout':
-      html = signout(props)
-      break
-    case 'verify-request':
-      html = verifyRequest(props)
-      break
-    case 'error':
-      html = error({ ...props, res })
-      if (html === false) return done()
-      break
-    default:
-      html = error(props)
-      return
-  }
+/** Takes a request and response, and gives renderable pages */
+export default function renderPage (req, res) {
+  const { baseUrl, basePath, callbackUrl, csrfToken, providers, theme } = req.options
 
   res.setHeader('Content-Type', 'text/html')
-  res.send(`<!DOCTYPE html><head><style type="text/css">${css()}</style><meta name="viewport" content="width=device-width, initial-scale=1"></head><body><div class="page">${html}</div></body></html>`)
-  done()
-}
+  function send (html) {
+    res.send(`<!DOCTYPE html><head><style type="text/css">${css()}</style><meta name="viewport" content="width=device-width, initial-scale=1"></head><body class="__next-auth-theme-${theme}"><div class="page">${html}</div></body></html>`)
+  }
 
-export default {
-  render
+  return {
+    signin (props) { send(signin({ csrfToken, providers, callbackUrl, ...req.query, ...props })) },
+    signout (props) { send(signout({ csrfToken, baseUrl, basePath, ...props })) },
+    verifyRequest (props) { send(verifyRequest({ baseUrl, ...props })) },
+    error (props) { send(error({ basePath, baseUrl, res, ...props })) }
+  }
 }

src/server/pages/signin.js

@@ -1,9 +1,7 @@
 import { h } from 'preact' // eslint-disable-line no-unused-vars
 import render from 'preact-render-to-string'
 
-export default ({ req, csrfToken, providers, callbackUrl }) => {
-  const { email, error } = req.query
-
+export default function signin ({ csrfToken, providers, callbackUrl, email, error: errorType }) {
   // We only want to render providers
   const providersToRender = providers.filter(provider => {
     if (provider.type === 'oauth' || provider.type === 'email') {
@@ -12,43 +10,31 @@ export default ({ req, csrfToken, providers, callbackUrl }) => {
     } else if (provider.type === 'credentials' && provider.credentials) {
       // Only render credentials type provider if credentials are defined
       return true
-    } else {
-      // Don't render other provider types
-      return false
     }
+    // Don't render other provider types
+    return false
   })
 
-  let errorMessage
-  if (error) {
-    switch (error) {
-      case 'Signin':
-      case 'OAuthSignin':
-      case 'OAuthCallback':
-      case 'OAuthCreateAccount':
-      case 'EmailCreateAccount':
-      case 'Callback':
-        errorMessage = <p>Try signing with a different account.</p>
-        break
-      case 'OAuthAccountNotLinked':
-        errorMessage = <p>To confirm your identity, sign in with the same account you used originally.</p>
-        break
-      case 'EmailSignin':
-        errorMessage = <p>Check your email address.</p>
-        break
-      case 'CredentialsSignin':
-        errorMessage = <p>Sign in failed. Check the details you provided are correct.</p>
-        break
-      default:
-        errorMessage = <p>Unable to sign in.</p>
-        break
-    }
+  const errors = {
+    Signin: 'Try signing with a different account.',
+    OAuthSignin: 'Try signing with a different account.',
+    OAuthCallback: 'Try signing with a different account.',
+    OAuthCreateAccount: 'Try signing with a different account.',
+    EmailCreateAccount: 'Try signing with a different account.',
+    Callback: 'Try signing with a different account.',
+    OAuthAccountNotLinked: 'To confirm your identity, sign in with the same account you used originally.',
+    EmailSignin: 'Check your email address.',
+    CredentialsSignin: 'Sign in failed. Check the details you provided are correct.',
+    default: 'Unable to sign in.'
   }
 
+  const error = errorType && (errors[errorType] ?? errors.default)
+
   return render(
     <div className='signin'>
-      {errorMessage &&
+      {error &&
         <div className='error'>
-          {errorMessage}
+          <p>{error}</p>
         </div>}
       {providersToRender.map((provider, i) =>
         <div key={provider.id} className='provider'>
@@ -59,8 +45,8 @@ export default ({ req, csrfToken, providers, 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 />}
+          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} />

src/server/pages/signout.js

@@ -1,7 +1,7 @@
 import { h } from 'preact' // eslint-disable-line no-unused-vars
 import render from 'preact-render-to-string'
 
-export default ({ baseUrl, basePath, csrfToken }) => {
+export default function signout ({ baseUrl, basePath, csrfToken }) {
   return render(
     <div className='signout'>
       <h1>Are you sure you want to sign out?</h1>

src/server/pages/verify-request.js

@@ -1,7 +1,7 @@
 import { h } from 'preact' // eslint-disable-line no-unused-vars
 import render from 'preact-render-to-string'
 
-export default ({ baseUrl }) => {
+export default function verifyRequest ({ baseUrl }) {
   return render(
     <div className='verify-request'>
       <h1>Check your email</h1>

src/server/routes/callback.js

@@ -1,14 +1,13 @@
-// Handle callbacks from login services
 import oAuthCallback from '../lib/oauth/callback'
 import callbackHandler from '../lib/callback-handler'
-import cookie from '../lib/cookie'
+import * as cookie from '../lib/cookie'
 import logger from '../../lib/logger'
 import dispatchEvent from '../lib/dispatch-event'
 
-export default async (req, res, options, done) => {
+/** Handle callbacks from login services */
+export default async function callback (req, res) {
   const {
-    provider: providerName,
-    providers,
+    provider,
     adapter,
     baseUrl,
     basePath,
@@ -19,133 +18,132 @@ export default async (req, res, options, done) => {
     jwt,
     events,
     callbacks,
-    csrfToken,
-    redirect
-  } = options
-  const provider = providers[providerName]
-  const { type } = provider
-  const useJwtSession = options.session.jwt
-  const sessionMaxAge = options.session.maxAge
+    session: {
+      jwt: useJwtSession,
+      maxAge: sessionMaxAge
+    }
+  } = req.options
 
   // Get session ID (if set)
-  const sessionToken = req.cookies ? req.cookies[cookies.sessionToken.name] : null
+  const sessionToken = req.cookies?.[cookies.sessionToken.name] ?? null
 
-  if (type === 'oauth') {
+  if (provider.type === 'oauth') {
     try {
-      oAuthCallback(req, provider, csrfToken, async (error, profile, account, OAuthProfile) => {
-        try {
-          if (error) {
-            logger.error('CALLBACK_OAUTH_ERROR', error)
-            return redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
-          }
+      const { profile, account, OAuthProfile } = await oAuthCallback(req)
+      try {
+        // Make it easier to debug when adding a new provider
+        logger.debug('OAUTH_CALLBACK_RESPONSE', { profile, account, OAuthProfile })
 
-          // Make it easier to debug when adding a new provider
-          logger.debug('OAUTH_CALLBACK_RESPONSE', { profile, account, OAuthProfile })
+        // If we don't have a profile object then either something went wrong
+        // or the user cancelled signin in. We don't know which, so we just
+        // direct the user to the signup page for now. We could do something
+        // else in future.
+        //
+        // Note: In oAuthCallback an error is logged with debug info, so it
+        // 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`)
+        }
 
-          // If we don't have a profile object then either something went wrong
-          // or the user cancelled signin in. We don't know which, so we just
-          // direct the user to the signup page for now. We could do something
-          // else in future.
-          //
-          // Note: In oAuthCallback an error is logged with debug info, so it
-          // should at least be visible to developers what happened if it is an
-          // error with the provider.
-          if (!profile) {
-            return redirect(`${baseUrl}${basePath}/signin`)
-          }
-
-          // Check if user is allowed to sign in
-          // Attempt to get Profile from OAuth provider details before invoking
-          // signIn callback - but if no user object is returned, that is fine
-          // (that just means it's a new user signing in for the first time).
-          let userOrProfile = profile
-          if (adapter) {
-            const { getUserByProviderAccountId } = await adapter.getAdapter(options)
-            const userFromProviderAccountId = await getUserByProviderAccountId(account.provider, account.id)
-            if (userFromProviderAccountId) {
-              userOrProfile = userFromProviderAccountId
-            }
-          }
-
-          try {
-            const signInCallbackResponse = await callbacks.signIn(userOrProfile, account, OAuthProfile)
-            if (signInCallbackResponse === false) {
-              return redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
-            }
-          } catch (error) {
-            if (error instanceof Error) {
-              return redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
-            } else {
-              return redirect(error)
-            }
-          }
-
-          // Sign user in
-          const { user, session, isNewUser } = await callbackHandler(sessionToken, profile, account, options)
-
-          if (useJwtSession) {
-            const defaultJwtPayload = {
-              name: user.name,
-              email: user.email,
-              picture: user.image
-            }
-            const jwtPayload = await callbacks.jwt(defaultJwtPayload, user, account, OAuthProfile, isNewUser)
-
-            // Sign and encrypt token
-            const newEncodedJwt = await jwt.encode({ ...jwt, token: jwtPayload })
-
-            // Set cookie expiry date
-            const cookieExpires = new Date()
-            cookieExpires.setTime(cookieExpires.getTime() + (sessionMaxAge * 1000))
-
-            cookie.set(res, cookies.sessionToken.name, newEncodedJwt, { expires: cookieExpires.toISOString(), ...cookies.sessionToken.options })
-          } else {
-            // Save Session Token in cookie
-            cookie.set(res, cookies.sessionToken.name, session.sessionToken, { expires: session.expires || null, ...cookies.sessionToken.options })
-          }
-
-          await dispatchEvent(events.signIn, { user, account, isNewUser })
-
-          // Handle first logins on new accounts
-          // e.g. option to send users to a new account landing page on initial login
-          // Note that the callback URL is preserved, so the journey can still be resumed
-          if (isNewUser && pages.newUser) {
-            return redirect(pages.newUser)
-          }
-
-          // Callback URL is already verified at this point, so safe to use if specified
-          return redirect(callbackUrl || baseUrl)
-        } catch (error) {
-          if (error.name === 'AccountNotLinkedError') {
-            // If the email on the account is already linked, but nto with this oAuth account
-            return redirect(`${baseUrl}${basePath}/error?error=OAuthAccountNotLinked`)
-          } else if (error.name === 'CreateUserError') {
-            return redirect(`${baseUrl}${basePath}/error?error=OAuthCreateAccount`)
-          } else {
-            logger.error('OAUTH_CALLBACK_HANDLER_ERROR', error)
-            return redirect(`${baseUrl}${basePath}/error?error=Callback`)
+        // Check if user is allowed to sign in
+        // Attempt to get Profile from OAuth provider details before invoking
+        // signIn callback - but if no user object is returned, that is fine
+        // (that just means it's a new user signing in for the first time).
+        let userOrProfile = profile
+        if (adapter) {
+          const { getUserByProviderAccountId } = await adapter.getAdapter(req.options)
+          const userFromProviderAccountId = await getUserByProviderAccountId(account.provider, account.id)
+          if (userFromProviderAccountId) {
+            userOrProfile = userFromProviderAccountId
           }
         }
-      })
+
+        try {
+          const signInCallbackResponse = await callbacks.signIn(userOrProfile, account, OAuthProfile)
+          if (signInCallbackResponse === false) {
+            return res.redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+          } else if (typeof signInCallbackResponse === 'string') {
+            return res.redirect(signInCallbackResponse)
+          }
+        } catch (error) {
+          if (error instanceof Error) {
+            return res.redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
+          }
+          // TODO: Remove in a future major release
+          logger.warn('SIGNIN_CALLBACK_REJECT_REDIRECT')
+          return res.redirect(error)
+        }
+
+        // Sign user in
+        const { user, session, isNewUser } = await callbackHandler(sessionToken, profile, account, req.options)
+
+        if (useJwtSession) {
+          const defaultJwtPayload = {
+            name: user.name,
+            email: user.email,
+            picture: user.image,
+            sub: user.id?.toString()
+          }
+          const jwtPayload = await callbacks.jwt(defaultJwtPayload, user, account, OAuthProfile, isNewUser)
+
+          // Sign and encrypt token
+          const newEncodedJwt = await jwt.encode({ ...jwt, token: jwtPayload })
+
+          // 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 })
+        } else {
+          // Save Session Token in cookie
+          cookie.set(res, cookies.sessionToken.name, session.sessionToken, { expires: session.expires || null, ...cookies.sessionToken.options })
+        }
+
+        await dispatchEvent(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(`${pages.newUser}${pages.newUser.includes('?') ? '&' : '?'}callbackUrl=${encodeURIComponent(callbackUrl)}`)
+        }
+
+        // Callback URL is already verified at this point, so safe to use if specified
+        return res.redirect(callbackUrl || baseUrl)
+      } catch (error) {
+        if (error.name === 'AccountNotLinkedError') {
+          // If the email on the account is already linked, but not with this OAuth account
+          return res.redirect(`${baseUrl}${basePath}/error?error=OAuthAccountNotLinked`)
+        } else if (error.name === 'CreateUserError') {
+          return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCreateAccount`)
+        }
+        logger.error('OAUTH_CALLBACK_HANDLER_ERROR', error)
+        return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
+      }
     } catch (error) {
+      if (error.name === 'OAuthCallbackError') {
+        logger.error('CALLBACK_OAUTH_ERROR', error)
+        return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
+      }
       logger.error('OAUTH_CALLBACK_ERROR', error)
-      return redirect(`${baseUrl}${basePath}/error?error=Callback`)
+      return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
     }
-  } else if (type === 'email') {
+  } else if (provider.type === 'email') {
     try {
       if (!adapter) {
         logger.error('EMAIL_REQUIRES_ADAPTER_ERROR')
-        return redirect(`${baseUrl}${basePath}/error?error=Configuration`)
+        return res.redirect(`${baseUrl}${basePath}/error?error=Configuration`)
       }
 
-      const { getVerificationRequest, deleteVerificationRequest, getUserByEmail } = await adapter.getAdapter(options)
+      const { getVerificationRequest, deleteVerificationRequest, getUserByEmail } = await adapter.getAdapter(req.options)
       const verificationToken = req.query.token
       const email = req.query.email
 
       // Verify email and verification token exist in database
       const invite = await getVerificationRequest(email, verificationToken, secret, provider)
       if (!invite) {
-        return redirect(`${baseUrl}${basePath}/error?error=Verification`)
+        return res.redirect(`${baseUrl}${basePath}/error?error=Verification`)
       }
 
       // If verification token is valid, delete verification request token from
@@ -160,24 +158,28 @@ export default async (req, res, options, done) => {
       try {
         const signInCallbackResponse = await callbacks.signIn(profile, account, { email })
         if (signInCallbackResponse === false) {
-          return redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+          return res.redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+        } else if (typeof signInCallbackResponse === 'string') {
+          return res.redirect(signInCallbackResponse)
         }
       } catch (error) {
         if (error instanceof Error) {
-          return redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
-        } else {
-          return redirect(error)
+          return res.redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
         }
+        // TODO: Remove in a future major release
+        logger.warn('SIGNIN_CALLBACK_REJECT_REDIRECT')
+        return res.redirect(error)
       }
 
       // Sign user in
-      const { user, session, isNewUser } = await callbackHandler(sessionToken, profile, account, options)
+      const { user, session, isNewUser } = await callbackHandler(sessionToken, profile, account, req.options)
 
       if (useJwtSession) {
         const defaultJwtPayload = {
           name: user.name,
           email: user.email,
-          picture: user.image
+          picture: user.image,
+          sub: user.id?.toString()
         }
         const jwtPayload = await callbacks.jwt(defaultJwtPayload, user, account, profile, isNewUser)
 
@@ -200,32 +202,27 @@ export default async (req, res, options, done) => {
       // 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 redirect(pages.newUser)
+        return res.redirect(`${pages.newUser}${pages.newUser.includes('?') ? '&' : '?'}callbackUrl=${encodeURIComponent(callbackUrl)}`)
       }
 
       // Callback URL is already verified at this point, so safe to use if specified
-      if (callbackUrl) {
-        return redirect(callbackUrl)
-      } else {
-        return redirect(baseUrl)
-      }
+      return res.redirect(callbackUrl || baseUrl)
     } catch (error) {
       if (error.name === 'CreateUserError') {
-        return redirect(`${baseUrl}${basePath}/error?error=EmailCreateAccount`)
-      } else {
-        logger.error('CALLBACK_EMAIL_ERROR', error)
-        return redirect(`${baseUrl}${basePath}/error?error=Callback`)
+        return res.redirect(`${baseUrl}${basePath}/error?error=EmailCreateAccount`)
       }
+      logger.error('CALLBACK_EMAIL_ERROR', error)
+      return res.redirect(`${baseUrl}${basePath}/error?error=Callback`)
     }
-  } else if (type === 'credentials' && req.method === 'POST') {
+  } else if (provider.type === 'credentials' && req.method === 'POST') {
     if (!useJwtSession) {
       logger.error('CALLBACK_CREDENTIALS_JWT_ERROR', 'Signin in with credentials is only supported if JSON Web Tokens are enabled')
-      return redirect(`${baseUrl}${basePath}/error?error=Configuration`)
+      return res.redirect(`${baseUrl}${basePath}/error?error=Configuration`)
     }
 
     if (!provider.authorize) {
       logger.error('CALLBACK_CREDENTIALS_HANDLER_ERROR', 'Must define an authorize() handler to use credentials authentication provider')
-      return redirect(`${baseUrl}${basePath}/error?error=Configuration`)
+      return res.redirect(`${baseUrl}${basePath}/error?error=Configuration`)
     }
 
     const credentials = req.body
@@ -234,14 +231,13 @@ export default async (req, res, options, done) => {
     try {
       userObjectReturnedFromAuthorizeHandler = await provider.authorize(credentials)
       if (!userObjectReturnedFromAuthorizeHandler) {
-        return redirect(`${baseUrl}${basePath}/error?error=CredentialsSignin&provider=${encodeURIComponent(provider.id)}`)
+        return res.redirect(`${baseUrl}${basePath}/error?error=CredentialsSignin&provider=${encodeURIComponent(provider.id)}`)
       }
     } catch (error) {
       if (error instanceof Error) {
-        return redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
-      } else {
-        return redirect(error)
+        return res.redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
       }
+      return res.redirect(error)
     }
 
     const user = userObjectReturnedFromAuthorizeHandler
@@ -250,14 +246,13 @@ export default async (req, res, options, done) => {
     try {
       const signInCallbackResponse = await callbacks.signIn(user, account, credentials)
       if (signInCallbackResponse === false) {
-        return redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+        return res.redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
       }
     } catch (error) {
       if (error instanceof Error) {
-        return redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
-      } else {
-        return redirect(error)
+        return res.redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
       }
+      return res.redirect(error)
     }
 
     const defaultJwtPayload = {
@@ -278,9 +273,7 @@ export default async (req, res, options, done) => {
 
     await dispatchEvent(events.signIn, { user, account })
 
-    return redirect(callbackUrl || baseUrl)
-  } else {
-    res.status(500).end(`Error: Callback for provider type ${type} not supported`)
-    return done()
+    return res.redirect(callbackUrl || baseUrl)
   }
+  return res.status(500).end(`Error: Callback for provider type ${provider.type} not supported`)
 }

src/server/routes/index.js

@@ -0,0 +1,5 @@
+export { default as callback } from './callback'
+export { default as signin } from './signin'
+export { default as signout } from './signout'
+export { default as session } from './session'
+export { default as providers } from './providers'

src/server/routes/providers.js

@@ -1,21 +1,15 @@
-// Return a JSON object with a list of all outh 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 (req, res, options, done) => {
-  const { providers } = options
+/**
+ * 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 (req, res) {
+  const { providers } = req.options
 
-  const result = {}
-  Object.entries(providers).map(([provider, providerConfig]) => {
-    result[provider] = {
-      id: provider,
-      name: providerConfig.name,
-      type: providerConfig.type,
-      signinUrl: providerConfig.signinUrl,
-      callbackUrl: providerConfig.callbackUrl
-    }
-  })
+  const result = providers.reduce((acc, { id, name, type, signinUrl, callbackUrl }) => {
+    acc[id] = { id, name, type, signinUrl, callbackUrl }
+    return acc
+  }, {})
 
-  res.setHeader('Content-Type', 'application/json')
   res.json(result)
-  return done()
 }

src/server/routes/session.js

@@ -1,18 +1,19 @@
-// Return a session object (without any private fields) for Single Page App clients
-import cookie from '../lib/cookie'
+import * as cookie from '../lib/cookie'
 import logger from '../../lib/logger'
 import dispatchEvent from '../lib/dispatch-event'
 
-export default async (req, res, options, done) => {
-  const { cookies, adapter, jwt, events, callbacks } = options
-  const useJwtSession = options.session.jwt
-  const sessionMaxAge = options.session.maxAge
+/**
+ * Return a session object (without any private fields)
+ * for Single Page App clients
+ */
+export default async function session (req, res) {
+  const { cookies, adapter, jwt, events, callbacks } = req.options
+  const useJwtSession = req.options.session.jwt
+  const sessionMaxAge = req.options.session.maxAge
   const sessionToken = req.cookies[cookies.sessionToken.name]
 
   if (!sessionToken) {
-    res.setHeader('Content-Type', 'application/json')
-    res.json({})
-    return done()
+    return res.json({})
   }
 
   let response = {}
@@ -58,7 +59,7 @@ export default async (req, res, options, done) => {
     }
   } else {
     try {
-      const { getUser, getSession, updateSession } = await adapter.getAdapter(options)
+      const { getUser, getSession, updateSession } = await adapter.getAdapter(req.options)
       const session = await getSession(sessionToken)
       if (session) {
         // Trigger update to session object to update session expiry
@@ -98,7 +99,5 @@ export default async (req, res, options, done) => {
     }
   }
 
-  res.setHeader('Content-Type', 'application/json')
   res.json(response)
-  return done()
 }

src/server/routes/signin.js

@@ -1,52 +1,42 @@
-// Handle requests to /api/auth/signin
-import oAuthSignin from '../lib/signin/oauth'
+import getAuthorizationUrl from '../lib/signin/oauth'
 import emailSignin from '../lib/signin/email'
 import logger from '../../lib/logger'
 
-export default async (req, res, options, done) => {
+/** Handle requests to /api/auth/signin */
+export default async function signin (req, res) {
   const {
-    provider: providerName,
-    providers,
+    provider,
     baseUrl,
     basePath,
     adapter,
-    callbacks,
-    csrfToken,
-    redirect
-  } = options
-  const provider = providers[providerName]
-  const { type } = provider
+    callbacks
+  } = req.options
 
-  if (!type) {
-    res.status(500).end(`Error: Type not specified for ${provider}`)
-    return done()
+  if (!provider.type) {
+    return res.status(500).end(`Error: Type not specified for ${provider.name}`)
   }
 
-  if (type === 'oauth' && req.method === 'POST') {
-    const authParams = { ...req.query }
-    delete authParams.nextauth // This is probably not intended to be sent to the provider, remove
-
-    oAuthSignin(provider, csrfToken, (error, oAuthSigninUrl) => {
-      if (error) {
-        logger.error('SIGNIN_OAUTH_ERROR', error)
-        return redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
-      }
-
-      return redirect(oAuthSigninUrl)
-    }, authParams)
-  } else if (type === 'email' && req.method === 'POST') {
+  if (provider.type === 'oauth' && req.method === 'POST') {
+    try {
+      const authorizationUrl = await getAuthorizationUrl(req)
+      return res.redirect(authorizationUrl)
+    } catch (error) {
+      logger.error('SIGNIN_OAUTH_ERROR', error)
+      return res.redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
+    }
+  } else if (provider.type === 'email' && req.method === 'POST') {
     if (!adapter) {
       logger.error('EMAIL_REQUIRES_ADAPTER_ERROR')
-      return redirect(`${baseUrl}${basePath}/error?error=Configuration`)
+      return res.redirect(`${baseUrl}${basePath}/error?error=Configuration`)
     }
-    const { getUserByEmail } = await adapter.getAdapter(options)
+    const { getUserByEmail } = await adapter.getAdapter(req.options)
 
     // 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 = req.body.email ? req.body.email.toLowerCase() : null
+    const email = req.body.email?.toLowerCase() ?? null
 
     // If is an existing user return a user object (otherwise use placeholder)
     const profile = await getUserByEmail(email) || { email }
@@ -54,29 +44,31 @@ export default async (req, res, options, done) => {
 
     // Check if user is allowed to sign in
     try {
-      const signinCallbackResponse = await callbacks.signIn(profile, account, { email, verificationRequest: true })
-      if (signinCallbackResponse === false) {
-        return redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+      const signInCallbackResponse = await callbacks.signIn(profile, account, { email })
+      if (signInCallbackResponse === false) {
+        return res.redirect(`${baseUrl}${basePath}/error?error=AccessDenied`)
+      } else if (typeof signInCallbackResponse === 'string') {
+        return res.redirect(signInCallbackResponse)
       }
     } catch (error) {
       if (error instanceof Error) {
-        return redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
-      } else {
-        return redirect(error)
+        return res.redirect(`${baseUrl}${basePath}/error?error=${encodeURIComponent(error)}`)
       }
+      // TODO: Remove in a future major release
+      logger.warn('SIGNIN_CALLBACK_REJECT_REDIRECT')
+      return res.redirect(error)
     }
 
     try {
-      await emailSignin(email, provider, options)
+      await emailSignin(email, provider, req.options)
     } catch (error) {
       logger.error('SIGNIN_EMAIL_ERROR', error)
-      return redirect(`${baseUrl}${basePath}/error?error=EmailSignin`)
+      return res.redirect(`${baseUrl}${basePath}/error?error=EmailSignin`)
     }
 
-    return redirect(`${baseUrl}${basePath}/verify-request?provider=${encodeURIComponent(
+    return res.redirect(`${baseUrl}${basePath}/verify-request?provider=${encodeURIComponent(
       provider.id
     )}&type=${encodeURIComponent(provider.type)}`)
-  } else {
-    return redirect(`${baseUrl}${basePath}/signin`)
   }
+  return res.redirect(`${baseUrl}${basePath}/signin`)
 }

src/server/routes/signout.js

@@ -1,11 +1,11 @@
-// Handle requests to /api/auth/signout
-import cookie from '../lib/cookie'
+import * as cookie from '../lib/cookie'
 import logger from '../../lib/logger'
 import dispatchEvent from '../lib/dispatch-event'
 
-export default async (req, res, options, done) => {
-  const { adapter, cookies, events, jwt, callbackUrl, redirect } = options
-  const useJwtSession = options.session.jwt
+/** Handle requests to /api/auth/signout */
+export default async function signout (req, res) {
+  const { adapter, cookies, events, jwt, callbackUrl } = req.options
+  const useJwtSession = req.options.session.jwt
   const sessionToken = req.cookies[cookies.sessionToken.name]
 
   if (useJwtSession) {
@@ -18,7 +18,7 @@ export default async (req, res, options, done) => {
     }
   } else {
     // Get session from database
-    const { getSession, deleteSession } = await adapter.getAdapter(options)
+    const { getSession, deleteSession } = await adapter.getAdapter(req.options)
 
     try {
       // Dispatch signout event
@@ -43,5 +43,5 @@ export default async (req, res, options, done) => {
     maxAge: 0
   })
 
-  return redirect(callbackUrl)
+  return res.redirect(callbackUrl)
 }

test/docker/app/package.json

@@ -11,7 +11,7 @@
   "author": "Iain Collins <me@iaincollins.com>",
   "license": "ISC",
   "dependencies": {
-    "next": "^9.5.0",
+    "next": "^9.5.4",
     "react": "^16.13.1",
     "react-dom": "^16.13.1"
   }

test/docker/app/pages/api/auth/[...nextauth].js

@@ -81,8 +81,8 @@ const options = {
 
     // You can define your own encode/decode functions for signing and encryption
     // if you want to override the default behaviour.
-    // encode: async ({ secret, token, maxAge }) => {},
-    // decode: async ({ secret, token, maxAge }) => {},
+    // async encode({ secret, token, maxAge }) {},
+    // async decode({ secret, token, maxAge }) {},
   },
 
   // You can define custom pages to override the built-in pages.
@@ -101,10 +101,10 @@ const options = {
   // when an action is performed.
   // https://next-auth.js.org/configuration/callbacks
   callbacks: {
-    // signIn: async (user, account, profile) => { return Promise.resolve(true) },
-    // redirect: async (url, baseUrl) => { return Promise.resolve(baseUrl) },
-    // session: async (session, user) => { return Promise.resolve(session) },
-    // jwt: async (token, user, account, profile, isNewUser) => { return Promise.resolve(token) }
+    // async signIn(user, account, profile) { return Promise.resolve(true) },
+    // async redirect(url, baseUrl) { return Promise.resolve(baseUrl) },
+    // async session(session, user) { return Promise.resolve(session) },
+    // async jwt(token, user, account, profile, isNewUser) { return Promise.resolve(token) }
   },
 
   // Events are useful for logging

test/docker/databases.yml

@@ -33,4 +33,4 @@ services:
       file: databases/postgres.yml
       service: postgres
     ports:
-      - "5432:5432"
+      - "5432:5432"