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Adds conformance checks for PKCE requirements from the MCP auth spec: - pkce-code-challenge-sent: Verifies client sends code_challenge in auth request - pkce-s256-method-used: Verifies client uses S256 code challenge method - pkce-code-verifier-sent: Verifies client sends code_verifier in token request - pkce-verifier-matches-challenge: Validates BASE64URL(SHA256(verifier)) = challenge Also adds auth/pkce-no-s256-support scenario that tests clients correctly refuse when S256 is not in code_challenge_methods_supported. All PKCE checks are added to the createAuthServer helper, so they automatically apply to all existing auth scenarios. Fixes #77
Adds auth-test-no-pkce.ts which implements a custom OAuth flow that deliberately skips PKCE (no code_challenge in auth request, no code_verifier in token request). Also adds negative test to verify the conformance suite correctly detects this non-compliant behavior.
commit: |
- Remove pkce-no-s256-support scenario (was skipped anyway) - Make pkce-verifier-matches-challenge fail if either code_challenge or code_verifier is missing, rather than only running when both present - Update negative test to expect the new failure
felixweinberger
approved these changes
Jan 23, 2026
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LGTM! |
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Summary
Adds conformance tests for PKCE requirements from the MCP authorization spec (fixes #77).
Changes
New PKCE Checks (added to all auth scenarios via
createAuthServer)pkce-code-challenge-sentcode_challengein authorization requestpkce-s256-method-usedcode_challenge_method=S256pkce-code-verifier-sentcode_verifierin token requestpkce-verifier-matches-challengeBASE64URL(SHA256(code_verifier)) === code_challengeNew Scenario (skipped for now)
auth/pkce-no-s256-support- Tests that clients refuse when S256 is not incode_challenge_methods_supportedNew Bad Client Example
auth-test-no-pkce.ts- A client that skips PKCE entirely (for negative testing)Testing
All existing auth scenarios now include PKCE validation. The bad client example correctly fails all PKCE checks: