feat: rename protection to checks (nextauthjs#2255)

This change aligns the API with `openid-client`'s `checks` https://github.com/panva/node-openid-client/blob/main/docs/README.md#clientcallbackredirecturi-parameters-checks-extras, a library which we intend to migrate to in the future. Aligning our API early, so people get used to it.

Also, objectively the name `protection` might not have been as clear as I first thought. `checks` better describe the intention.

BREAKING CHANGE:

The `state` option on OAuth providers is now deprecated. Use `checks: ["state"]` instead.
`protections` is renamed to `checks`, here is an example:
```diff
- protection: ["pkce"]
+ checks: ["pkece"]
```

Furthermore, string values are not supported anymore. This is to be able to handle fewer cases internally.
```diff
- checks: "state"
+ checks: ["state"]
```

README.md

@@ -83,8 +83,6 @@ Advanced options allow you to define your own routines to handle controlling wha
 
 NextAuth.js comes with built-in types. For more information and usage, check out the [TypeScript section](https://next-auth.js.org/getting-started/typescript) in the documentation.
 
-The package at `@types/next-auth` is now deprecated.
-
 ## Example
 
 ### Add API Route

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

@@ -41,11 +41,11 @@ export default NextAuth({
       clientSecret: process.env.AUTH0_SECRET,
       domain: process.env.AUTH0_DOMAIN,
       // Used to debug https://github.com/nextauthjs/next-auth/issues/1664
-      // protection: ["pkce", "state"],
+      // checks: ["pkce", "state"],
       // authorizationParams: {
       //   response_mode: 'form_post'
       // }
-      protection: "pkce",
+      checks: ["pkce"],
     }),
     TwitterProvider({
       clientId: process.env.TWITTER_ID,

src/providers/apple.js

@@ -28,7 +28,7 @@ export default function Apple(options) {
       privateKey: null,
       keyId: null,
     },
-    protection: "none", // REVIEW: Apple does not support state, as far as I know. Can we use "pkce" then?
+    checks: ["none"], // REVIEW: Apple does not support state, as far as I know. Can we use "pkce" then?
     ...options,
   }
 }

src/providers/dropbox.js

@@ -48,7 +48,7 @@ export default function Dropbox(options) {
         email_verified: profile.email_verified,
       }
     },
-    protection: ["state", "pkce"],
+    checks: ["state", "pkce"],
     ...options,
   }
 }

src/providers/naver.js

@@ -5,7 +5,7 @@ export default function Naver(options) {
     type: "oauth",
     version: "2.0",
     params: { grant_type: "authorization_code" },
-    protection: ["state"],
+    checks: ["state"],
     accessTokenUrl: "https://nid.naver.com/oauth2.0/token",
     authorizationUrl:
       "https://nid.naver.com/oauth2.0/authorize?response_type=code",

src/providers/salesforce.js

@@ -9,7 +9,7 @@ export default function Salesforce(options) {
     authorizationUrl:
       "https://login.salesforce.com/services/oauth2/authorize?response_type=code",
     profileUrl: "https://login.salesforce.com/services/oauth2/userinfo",
-    protection: "none",
+    checks: ["none"],
     profile(profile) {
       return {
         ...profile,

src/server/index.js

@@ -77,26 +77,16 @@ async function NextAuthHandler(req, res, userOptions) {
       baseUrl,
       basePath,
     })
+
     const provider = providers.find(({ id }) => id === providerId)
 
-    // Protection only works on OAuth 2.x providers
-    // TODO:
-    // - rename to `checks` in 4.x, so it is similar to `openid-client`
-    // - stop supporting `protection` as string
-    // - remove `state` property
-    if (provider?.type === "oauth" && provider.version?.startsWith("2")) {
-      // Priority: (protection array > protection string) > state > default
-      if (provider.protection) {
-        provider.protection = Array.isArray(provider.protection)
-          ? provider.protection
-          : [provider.protection]
-      } else if (provider.state !== undefined) {
-        provider.protection = [provider.state ? "state" : "none"]
-      } else {
-        // Default to state, as we did in 3.1
-        // REVIEW: should we use "pkce" or "none" as default?
-        provider.protection = ["state"]
-      }
+    // Checks only work on OAuth 2.x providers
+    if (
+      provider?.type === "oauth" &&
+      provider.version?.startsWith("2") &&
+      !provider.checks
+    ) {
+      provider.checks = ["state"]
     }
 
     const maxAge = 30 * 24 * 60 * 60 // Sessions expire after 30 days of being idle

src/server/lib/oauth/client.js

@@ -173,7 +173,7 @@ async function getOAuth2AccessToken(code, provider, codeVerifier) {
     headers.Authorization = `Bearer ${code}`
   }
 
-  if (provider.protection.includes("pkce")) {
+  if (provider.checks.includes("pkce")) {
     params.code_verifier = codeVerifier
   }
 

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

@@ -1,48 +1,48 @@
-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'
+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_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
  * @param {import("types/internals").NextAuthRequest} req
  * @param {import("types/internals").NextAuthResponse} res
  */
-export async function handleCallback (req, res) {
+export async function handleCallback(req, res) {
   const { cookies, provider, baseUrl, basePath } = req.options
   try {
     // Provider does not support PKCE, nothing to do.
-    if (!provider.protection?.includes('pkce')) {
+    if (!provider.checks?.includes("pkce")) {
       return
     }
 
     if (!(cookies.pkceCodeVerifier.name in req.cookies)) {
-      throw new OAuthCallbackError('The code_verifier cookie was not found.')
+      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
+      encryption: true,
     })
     req.options.pkce = pkce
-    logger.debug('OAUTH_CALLBACK_PROTECTION', 'Read PKCE verifier from cookie', {
+    logger.debug("OAUTH_CALLBACK_CHECK", "Read PKCE verifier from cookie", {
       code_verifier: pkce.code_verifier,
       pkceLength: PKCE_LENGTH,
-      method: PKCE_CODE_CHALLENGE_METHOD
+      method: PKCE_CODE_CHALLENGE_METHOD,
     })
     // remove PKCE after it has been used
     cookie.set(res, cookies.pkceCodeVerifier.name, "", { 
       ...cookies.pkceCodeVerifier.options,
       maxAge: 0 
     })
   } catch (error) {
-    logger.error('CALLBACK_OAUTH_ERROR', error)
+    logger.error("CALLBACK_OAUTH_ERROR", error)
     return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
   }
 }
@@ -52,42 +52,46 @@ export async function handleCallback (req, res) {
  * @param {import("types/internals").NextAuthRequest} req
  * @param {import("types/internals").NextAuthResponse} res
  */
-export async function handleSignin (req, res) {
+export async function handleSignin(req, res) {
   const { cookies, provider, baseUrl, basePath } = req.options
   try {
-    if (!provider.protection?.includes('pkce')) { // Provider does not support PKCE, nothing to do.
+    if (!provider.checks?.includes("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', {
+    logger.debug("OAUTH_SIGNIN_CHECK", "Created PKCE challenge/verifier", {
       ...pkce,
       pkceLength: PKCE_LENGTH,
-      method: PKCE_CODE_CHALLENGE_METHOD
+      method: PKCE_CODE_CHALLENGE_METHOD,
     })
 
     provider.authorizationParams = {
       ...provider.authorizationParams,
       code_challenge: pkce.code_challenge,
-      code_challenge_method: PKCE_CODE_CHALLENGE_METHOD
+      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
+      encryption: true,
     })
 
     const cookieExpires = new Date()
-    cookieExpires.setTime(cookieExpires.getTime() + (PKCE_MAX_AGE * 1000))
+    cookieExpires.setTime(cookieExpires.getTime() + PKCE_MAX_AGE * 1000)
     cookie.set(res, cookies.pkceCodeVerifier.name, encryptedCodeVerifier, {
       expires: cookieExpires.toISOString(),
-      ...cookies.pkceCodeVerifier.options
+      ...cookies.pkceCodeVerifier.options,
     })
-    logger.debug('OAUTH_SIGNIN_PROTECTION', 'Created PKCE code_verifier saved in cookie')
+    logger.debug(
+      "OAUTH_SIGNIN_CHECK",
+      "Created PKCE code_verifier saved in cookie"
+    )
   } catch (error) {
-    logger.error('SIGNIN_OAUTH_ERROR', error)
+    logger.error("SIGNIN_OAUTH_ERROR", error)
     return res.redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
   }
 }

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

@@ -1,6 +1,6 @@
-import { createHash } from 'crypto'
-import logger from '../../../lib/logger'
-import { OAuthCallbackError } from '../../../lib/errors'
+import { createHash } from "crypto"
+import logger from "../../../lib/logger"
+import { OAuthCallbackError } from "../../../lib/errors"
 
 /**
  * For OAuth 2.0 flows, if the provider supports state,
@@ -9,27 +9,27 @@ import { OAuthCallbackError } from '../../../lib/errors'
  * @param {import("types/internals").NextAuthRequest} req
  * @param {import("types/internals").NextAuthResponse} res
  */
-export async function handleCallback (req, res) {
+export async function handleCallback(req, res) {
   const { csrfToken, provider, baseUrl, basePath } = req.options
   try {
     // Provider does not support state, nothing to do.
-    if (!provider.protection?.includes('state')) {
+    if (!provider.checks?.includes("state")) {
       return
     }
 
     const state = req.query.state || req.body.state
-    const expectedState = createHash('sha256').update(csrfToken).digest('hex')
+    const expectedState = createHash("sha256").update(csrfToken).digest("hex")
 
     logger.debug(
-      'OAUTH_CALLBACK_PROTECTION',
-      'Comparing received and expected state',
+      "OAUTH_CALLBACK_CHECK",
+      "Comparing received and expected state",
       { state, expectedState }
     )
     if (state !== expectedState) {
-      throw new OAuthCallbackError('Invalid state returned from OAuth provider')
+      throw new OAuthCallbackError("Invalid state returned from OAuth provider")
     }
   } catch (error) {
-    logger.error('STATE_ERROR', error)
+    logger.error("STATE_ERROR", error)
     return res.redirect(`${baseUrl}${basePath}/error?error=OAuthCallback`)
   }
 }
@@ -39,31 +39,25 @@ export async function handleCallback (req, res) {
  * @param {import("types/internals").NextAuthRequest} req
  * @param {import("types/internals").NextAuthResponse} res
  */
-export async function handleSignin (req, res) {
+export async function handleSignin(req, res) {
   const { provider, baseUrl, basePath, csrfToken } = req.options
   try {
-    if (!provider.protection?.includes('state')) { // Provider does not support state, nothing to do.
+    if (!provider.checks?.includes("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')
+    const state = createHash("sha256").update(csrfToken).digest("hex")
 
     provider.authorizationParams = { ...provider.authorizationParams, state }
     logger.debug(
-      'OAUTH_CALLBACK_PROTECTION',
-      'Added state to authorization params',
+      "OAUTH_CALLBACK_CHECK",
+      "Added state to authorization params",
       { state }
     )
   } catch (error) {
-    logger.error('SIGNIN_OAUTH_ERROR', error)
+    logger.error("SIGNIN_OAUTH_ERROR", error)
     return res.redirect(`${baseUrl}${basePath}/error?error=OAuthSignin`)
   }
 }

types/providers.d.ts

@@ -14,7 +14,7 @@ export interface CommonProviderOptions {
  * OAuth Provider
  */
 
-type ProtectionType = "pkce" | "state" | "both" | "none"
+type ChecksType = "pkce" | "state" | "both" | "none"
 
 /**
  * OAuth provider options
@@ -34,18 +34,13 @@ export interface OAuthConfig<P extends Record<string, unknown> = Profile>
   authorizationUrl: string
   profileUrl: string
   profile(profile: P, tokens: TokenSet): Awaitable<User & { id: string }>
-  protection?: ProtectionType | ProtectionType[]
+  checks?: ChecksType | ChecksType[]
   clientId: string
   clientSecret:
     | string
     // TODO: only allow for Apple
     | Record<"appleId" | "teamId" | "privateKey" | "keyId", string>
   idToken?: boolean
-  /**
-   * @deprecated Will be removed in an upcoming major release. Use `protection: ["state"]` instead.
-   */
-  state?: boolean
-
   // TODO: only allow for BattleNet
   region?: string
   // TODO: only allow for some

www/docs/configuration/providers.md

@@ -92,8 +92,7 @@ providers: [
 |      clientId       |                 Client ID of the OAuth provider                  |           `string`            |   Yes    |
 |    clientSecret     |               Client Secret of the OAuth provider                |           `string`            |   Yes    |
 |       profile       |       A callback returning an object with the user's info        | `(profile, tokens) => Object` |   Yes    |
-|     protection      | Additional security for OAuth login flows (defaults to `state`)  |  `"pkce"`,`"state"`,`"none"`  |    No    |
-|        state        | Same as `protection: "state"`. Being deprecated, use protection. |           `boolean`           |    No    |
+|     checks      | Additional security checks on OAuth providers (default: [`state`])  |  `("pkce"|"state"|"none")[]`  |    No    |
 |       headers       |      Any headers that should be sent to the OAuth provider       |           `Object`            |    No    |
 | authorizationParams |    Additional params to be sent to the authorization endpoint    |           `Object`            |    No    |
 |       idToken       |   Set to `true` for services that use ID Tokens (e.g. OpenID)    |           `boolean`           |    No    |

www/docs/getting-started/rest-api.md

@@ -19,7 +19,7 @@ The POST submission requires CSRF token from `/api/auth/csrf`.
 
 Handles returning requests from OAuth services during sign in.
 
-For OAuth 2.0 providers that support the `state` option, the value of the `state` parameter is checked against the one that was generated when the sign in flow was started - this uses a hash of the CSRF token which MUST match for both the POST and `GET` calls during sign in.
+For OAuth 2.0 providers that support the `checks: ["state"]` option, the state parameter is checked against the one that was generated when the sign in flow was started - this uses a hash of the CSRF token which MUST match for both the POST and `GET` calls during sign in.
 
 #### `GET` /api/auth/signout
 

www/docs/getting-started/typescript.md

@@ -8,10 +8,6 @@ NextAuth.js comes with its own type definitions, so you can safely use it in you
 Check out the example repository showcasing how to use `next-auth` on a Next.js application with TypeScript:  
 https://github.com/nextauthjs/next-auth-typescript-example
 
-:::warning
-The types at [DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped) under the name of `@types/next-auth` are now deprecated, and not maintained anymore.
-:::
-
 ---
 
 ## Adapters

www/docs/providers/identity-server4.md

@@ -52,7 +52,7 @@ providers: [
     domain:  "demo.identityserver.io",
     clientId: "interactive.confidential",
     clientSecret: "secret",
-    protection: "pkce"
+    checks: ["pkce"]
   })
 }
 ...