github-starred/better-auth
2
0
Fork 0
mirror of https://github.com/better-auth/better-auth.git synced 2026-05-23 07:18:56 -05:00
Code Issues 2.5k Packages Projects Releases 112 Wiki Activity

Security: Google provider should verify nonce in verifyIdToken #2452

New Issue
Closed
opened 2026-03-13 09:55:44 -05:00 by GiteaMirror · 1 comment
GiteaMirror commented 2026-03-13 09:55:44 -05:00
Owner
Copy Link

Originally created by @j-xzy on GitHub (Dec 4, 2025).

Is this suited for github?

  • Yes, this is suited for github

Is your feature request related to a problem? Please describe.

No response

Describe the solution you'd like

The Google OAuth provider's verifyIdToken method currently accepts a nonce parameter but does not validate it against the ID token claims. This creates a security vulnerability as it allows potential replay attacks and doesn't follow OpenID Connect best practices.

Current implementation (packages/core/src/social-providers/google.ts:122-146):

  async verifyIdToken(token, nonce) {
      // ... validation logic ...
      // nonce parameter is received but never used
  }

Proposed solution:

  1. Decode the JWT to extract the nonce claim
  2. Compare it with the provided nonce parameter
  3. Return false if they don't match

Implementation approach:

  async verifyIdToken(token, nonce) {
      if (options.disableIdTokenSignIn) {
          return false;
      }
      if (options.verifyIdToken) {
          return options.verifyIdToken(token, nonce);
      }

      const googlePublicKeyUrl =
  `https://www.googleapis.com/oauth2/v3/tokeninfo?id_token=${token}`;
      const { data: tokenInfo } = await betterFetch<{
          aud: string;
          iss: string;
          email: string;
          email_verified: boolean;
          name: string;
          picture: string;
          sub: string;
          nonce?: string;  // Add nonce field
      }>(googlePublicKeyUrl);

      if (!tokenInfo) {
          return false;
      }

      // Verify nonce to prevent replay attacks
      if (nonce && tokenInfo.nonce !== nonce) {
          return false;
      }

      const isValid =
          tokenInfo.aud === options.clientId &&
          (tokenInfo.iss === "https://accounts.google.com" ||
              tokenInfo.iss === "accounts.google.com");
      return isValid;
  }

Why this matters:

  • Security: Prevents ID token replay attacks
  • OIDC Compliance: Aligns with OpenID Connect specification requirements
  • Consistency: The Apple provider (packages/core/src/social-providers/apple.ts:134-136) already
    implements nonce validation correctly
Originally created by @j-xzy on GitHub (Dec 4, 2025). ### Is this suited for github? - [x] Yes, this is suited for github ### Is your feature request related to a problem? Please describe. _No response_ ### Describe the solution you'd like The Google OAuth provider's verifyIdToken method currently accepts a nonce parameter but does not validate it against the ID token claims. This creates a security vulnerability as it allows potential replay attacks and doesn't follow OpenID Connect best practices. Current implementation (packages/core/src/social-providers/google.ts:122-146): ``` async verifyIdToken(token, nonce) { // ... validation logic ... // nonce parameter is received but never used } ``` Proposed solution: 1. Decode the JWT to extract the nonce claim 2. Compare it with the provided nonce parameter 3. Return false if they don't match Implementation approach: ``` async verifyIdToken(token, nonce) { if (options.disableIdTokenSignIn) { return false; } if (options.verifyIdToken) { return options.verifyIdToken(token, nonce); } const googlePublicKeyUrl = `https://www.googleapis.com/oauth2/v3/tokeninfo?id_token=${token}`; const { data: tokenInfo } = await betterFetch<{ aud: string; iss: string; email: string; email_verified: boolean; name: string; picture: string; sub: string; nonce?: string; // Add nonce field }>(googlePublicKeyUrl); if (!tokenInfo) { return false; } // Verify nonce to prevent replay attacks if (nonce && tokenInfo.nonce !== nonce) { return false; } const isValid = tokenInfo.aud === options.clientId && (tokenInfo.iss === "https://accounts.google.com" || tokenInfo.iss === "accounts.google.com"); return isValid; } ``` Why this matters: - Security: Prevents ID token replay attacks - OIDC Compliance: Aligns with OpenID Connect specification requirements - Consistency: The Apple provider (packages/core/src/social-providers/apple.ts:134-136) already implements nonce validation correctly
GiteaMirror added the security label 2026-03-13 09:55:44 -05:00
GiteaMirror commented 2026-03-13 09:55:45 -05:00
Author
Owner
Copy Link

@better-auth-agent[bot] commented on GitHub (Dec 4, 2025):

Hi there, thanks for raising this important security concern. To address this issue, you can update the Google provider's verifyIdToken method so that it decodes the token, extracts the nonce claim, and compares it against the provided nonce parameter. This will help prevent replay attacks and align with OIDC best practices, similar to what the Apple provider does [1]. One straightforward approach is to query the tokeninfo endpoint, validate the nonce from its response, and return false if there's a mismatch. Alternatively, you could migrate to using full JWT verification (using a library like jose), which would involve retrieving and caching Google’s public keys for more robust security [2]. How would you like to proceed on this – would a quick tokeninfo-based nonce check work for you, or are you leaning toward the full JWT verification approach? tag @better-auth-agent if you would like an answer from the Agent

If you need more help, tag @better-auth-agent in a comment so I can respond.

Diagram • Discord • GitHub

Diagram Join Star

@better-auth-agent[bot] commented on GitHub (Dec 4, 2025): Hi there, thanks for raising this important security concern. To address this issue, you can update the Google provider's verifyIdToken method so that it decodes the token, extracts the nonce claim, and compares it against the provided nonce parameter. This will help prevent replay attacks and align with OIDC best practices, similar to what the Apple provider does [[1]](https://github.com/better-auth/better-auth/issues/1183). One straightforward approach is to query the tokeninfo endpoint, validate the nonce from its response, and return false if there's a mismatch. Alternatively, you could migrate to using full JWT verification (using a library like jose), which would involve retrieving and caching Google’s public keys for more robust security [[2]](https://github.com/better-auth/better-auth/issues/6446). How would you like to proceed on this – would a quick tokeninfo-based nonce check work for you, or are you leaning toward the full JWT verification approach? tag @better-auth-agent if you would like an answer from the Agent _If you need more help, tag @better-auth-agent in a comment so I can respond._ <!-- bot:webhook reply v1 --> [Diagram](https://repodiagrams.s3.eu-north-1.amazonaws.com/skyvern_ultra_detailed_interactive.html) • [Discord](https://discord.gg/fG2XXEuQX3) • [GitHub](https://github.com/Skyvern-AI/Skyvern) [![Diagram](https://img.shields.io/badge/Diagram-2b3137?style=flat-square)](https://repodiagrams.s3.eu-north-1.amazonaws.com/skyvern_ultra_detailed_interactive.html) [![Join](https://img.shields.io/badge/join-5865F2?logo=discord&logoColor=white&style=flat-square)](https://discord.gg/fG2XXEuQX3) [![Star](https://img.shields.io/badge/star-181717?logo=github&logoColor=white&style=flat-square)](https://github.com/Skyvern-AI/Skyvern)
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
adapter
astro
awaiting external contributor
blocked
breaking
breaking change
bug
c-devops
core
credentials
database
dependencies
devops
devtools
docs
documentation
duplicate
elysia
enhancement
enterprise
expo
express
fastify
good first issue
help wanted
hono
identity
infra
integration
invalid
javascript
locked
maintenance
need-more-information
needs: info
needs: repro
nextjs
nuxt
oauth
organization
P0
payments
perf
platform
plugin
pull-request
Mirrored from GitHub Pull Request
 question
ready
regression
remix
security
social-provider
solid
stale
svelte
tanstack-start
tracking
version-bump
vue
wontfix
No Label security
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
GiteaMirror ninjasurge
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: github-starred/better-auth#2452
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?