feat(a2a): honor auth.oidcDiscoveryUrl for in-cluster JWKS fetch - #99
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The A2A server now consumes the optional auth.oidcDiscoveryUrl field frozen in values-interface.schema.json (FuzeFront#364 "Option B"): when set, signing keys are fetched from that in-cluster discovery URL's jwks_uri, while the token `iss` claim is STILL validated against the public oidcIssuerUrl. When unset, discovery is derived from oidcIssuerUrl exactly as before (purely additive). - config: parse oidcDiscoveryUrl into AuthConfig.oidc_discovery_url (default None) - runtime._build_verifier: injectable discovery-fetch / JWKS-client / decoder; _resolve_jwks_url picks the override vs the unchanged issuer-derived path; explicit iss anchoring to oidcIssuerUrl regardless of key source - unit tests: override used for key fetch when set; falls back when unset; iss rejected when != oidcIssuerUrl even with the override; config parsing Consumes the frozen contract; does not modify contracts/a2a/v1/**. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session-Id: 17fb89fd-3579-433b-a6c4-9c9e7f3ec549
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…etch (#102) Semgrep OSS (dynamic-urllib-use-detected) flagged the urllib fetch of the config-supplied oidcDiscoveryUrl: urllib also honours file://, so a dynamic discovery URL could read local files. oidcDiscoveryUrl is trusted operator config, but guarding the scheme up front is cheap, correct hardening. - runtime._require_http_url: reject any URL whose scheme is not in {http, https} (file://, ftp://, schemeless) with the existing discovery-config-error path. - _resolve_jwks_url guards oidcDiscoveryUrl BEFORE the fetch (fetch never happens for a bad scheme) and constrains the discovery doc's jwks_uri to http(s) too. - _http_get_json guards the URL before urllib.urlopen (defense in depth). - Behavior identical for valid http/https URLs. Unit tests: file://ftp://schemeless oidcDiscoveryUrl raises the config error and the fetch/JWKS-client never runs; a file:// jwks_uri from discovery is rejected. Follow-up to #99. Consumes the frozen contract; contracts/a2a/v1/** untouched. Claude-Session-Id: 17fb89fd-3579-433b-a6c4-9c9e7f3ec549 Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
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What
Makes the A2A server honor the optional
auth.oidcDiscoveryUrlfield (frozen invalues-interface.schema.json, #96) so it can fetch OIDC discovery + JWKS from an in-cluster URL while still anchoring trust to the public issuer — FuzeFront#364 "Option B".Behavior (matches the field's normative description)
oidcDiscoveryUrlset → fetch the discovery document at that URL, use itsjwks_urifor keys (typicallyhttp://authentik-server.<ns>.svc.cluster.local:9000/.../.well-known/openid-configuration).oidcIssuerUrlexactly as before (unchanged default path; purely additive).issis validated againstoidcIssuerUrl(NOT the discovery host),audagainstaudience, caller read fromcallerClaim. Keys come from in-cluster; trust stays anchored to the public issuer string.Changes
config.py: parseoidcDiscoveryUrl→AuthConfig.oidc_discovery_url(defaultNone).runtime.py:_resolve_jwks_urlselects override-vs-issuer-derived;_build_verifiertakes injectable discovery-fetch / JWKS-client / decoder and enforces explicitiss == oidcIssuerUrlregardless of key source.tests/test_runtime_verifier.py,tests/test_config.py): override used for key fetch when set; falls back when unset;issrejected when != issuer even with the override; config parsing.Scope
Consumes the frozen contract — does not touch
contracts/a2a/v1/**. Out of scope: #93 values wiring (devops), prod SealedSecrets (human), registration/token-decode.🤖 Generated with Claude Code