feat(provider): add Osso SAML provider (#1448)

Co-authored-by: @sbauch

src/providers/index.js

@@ -25,6 +25,7 @@ import MailRu from './mailru'
 import Medium from './medium'
 import Netlify from './netlify'
 import Okta from './okta'
+import Osso from './osso'
 import Reddit from './reddit'
 import Salesforce from './salesforce'
 import Slack from './slack'
@@ -63,6 +64,7 @@ export default {
   Medium,
   Netlify,
   Okta,
+  Osso,
   Reddit,
   Salesforce,
   Slack,

src/providers/osso.js

@@ -0,0 +1,20 @@
+export default (options) => {
+  return {
+    id: 'osso',
+    name: 'SAML SSO',
+    type: 'oauth',
+    version: '2.0',
+    params: { grant_type: 'authorization_code' },
+    accessTokenUrl: `https://${options.domain}/oauth/token`,
+    authorizationUrl: `https://${options.domain}/oauth/authorize?response_type=code`,
+    profileUrl: `https://${options.domain}/oauth/me`,
+    profile: (profile) => {
+      return {
+        id: profile.id,
+        name: profile.name || profile.email,
+        email: profile.email
+      }
+    },
+    ...options
+  }
+}

www/docs/providers/osso.md

@@ -0,0 +1,39 @@
+---
+id: osso
+title: Osso
+---
+
+## Documentation
+
+Osso is an open source service that handles SAML authentication against Identity Providers, normalizes profiles, and makes those profiles available to you in an OAuth 2.0 code grant flow.
+
+If you don't yet have an Osso instance, you can use [Osso's Demo App](https://demo.ossoapp.com) for your testing purposes. For documentation on deploying an Osso instance, see https://ossoapp.com/docs/deploy/overview/
+
+## Configuration
+
+You can configure your OAuth Clients on your Osso Admin UI, i.e. https://demo.ossoapp.com/admin/config - you'll need to get a Client ID and Secret and allow-list your redirect URIs.
+
+[SAML SSO differs a bit from OAuth](https://ossoapp.com/blog/saml-vs-oauth) - for every tenant who wants to sign in to your application using SAML, you and your customer need to perform a multi-step configuration in Osso's Admin UI and the admin dashboard of the tenant's Identity Provider. Osso provides documentation for providers like Okta and OneLogin, cloud-based IDPs who also offer a developer account that's useful for testing. Osso also provides a [Mock IDP](https://idp.ossoapp.com) that you can use for testing without needing to sign up for an Identity Provider service.
+
+See Osso's complete configuration and testing documentation at https://ossoapp.com/docs/configure/overview
+
+## Example
+
+A full example application is available at https://github.com/enterprise-oss/osso-next-auth-example and https://nextjs-demo.ossoapp.com
+
+```js
+import Providers from `next-auth/providers`
+...
+providers: [
+  Providers.Osso({
+    clientId: process.env.OSSO_CLIENT_ID,
+    clientSecret: process.env.OSSO_CLIENT_SECRET,
+    domain: process.env.OSSO_DOMAIN
+  })
+}
+...
+```
+
+:::note
+`domain` should be the fully qualified domain – e.g. `demo.ossoapp.com`
+:::