fix: gracefully skip JWKS keys with unsupported elliptic curves

[sergioperezcheco]

so I hit this issue where Telegram OIDC login is completely broken in Ory Kratos (ory/kratos#4572). The root cause is that Telegram recently added an ES256K key (secp256k1 curve) to their JWKS endpoint. go-jose doesn't support secp256k1, so when it tries to unmarshal the entire JWKS set, it fails on that one key and the whole set is rejected — even though the token is signed with RS256 which works fine.

The fix is pretty straightforward: in RemoteKeySet.updateKeys(), when the normal unmarshal of the full key set fails, fall back to parsing each key individually as raw JSON. Keys that can't be decoded (like the secp256k1 one) get silently skipped, and the rest are returned normally. If ALL keys fail, it returns an error so we don't silently return an empty set.

Added two tests: one for the mixed case (valid RSA + unsupported secp256k1 → RSA still works) and one for the all-unsupported case (proper error returned).

This affects any OIDC provider that uses key types not supported by go-jose. Telegram is the most prominent example right now.

Closes ory/kratos#4572

Summary by CodeRabbit

• Bug Fixes
  • Improved key handling so sign-in and token verification can still work when a JWKS contains an unsupported key type or curve.
  • Now skips only the unsupported keys and continues using any valid keys found.
  • Returns an error when no usable keys are available, preventing false success with an invalid key set.

[CLAassistant]

All committers have signed the CLA.

[coderabbitai]

Caution

Review failed

An error occurred during the review process. Please try again later.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[sergioperezcheco]

Hi maintainers — just checking if there's any update on this PR. It's a small, targeted fix that gracefully skips JWKS keys with unsupported elliptic curves (e.g. the EdDSA keys that Telegram's OIDC provider sends) instead of returning an error.

This also unblocks ory/kratos#4580, where the kratos maintainers are waiting for this to merge upstream before they can remove the fork dependency.

Happy to make any adjustments if needed!

[sergioperezcheco]

Hi @aeneasr — this is a small targeted fix that gracefully skips JWKS keys with unsupported elliptic curves (e.g. EdDSA keys from Telegram's OIDC provider) instead of returning an error.

It also unblocks ory/kratos#4580, which depends on this fix landing upstream. Would appreciate a review when you have a moment.

[sergioperezcheco]

Friendly ping — is there anything you'd like me to change here? The fix is small (per-key decode with skip-on-unsupported-curve, error only when all keys fail) and unblocks kratos#4580 which is currently breaking all Telegram OIDC logins. Happy to refactor, add tests, or adjust the error semantics if you have a preference.