Ankur Mhatre
4dc45d5e00
Companion code for the follow-up article. The repository now holds two Maven
projects sharing one docs/ tree:
jwt-authentication/ the hand-written filter application (unchanged, moved)
oauth2-resource-server/ a resource server, a Keycloak compose, and a stub
issuer whose JWK Set can be mutated on command
The stub exists because Keycloak will not rotate a signing key at a chosen
second, report how many times its JWKS endpoint was fetched, or drop a key from
the published set on request - and the caching and rotation measurements need
all three. The Keycloak run confirms the same code path against a real issuer.
Findings captured under docs/output/, all from real runs:
* The default validator stack does not check aud. A token minted for another
service in the same realm is accepted.
* Spring Security builds its JWKSource with refreshAheadCache(false) and
rateLimited(false), overriding two of Nimbus's protective defaults, and
enables Nimbus caching only when NO Spring cache was supplied - so
supplying one removes the five-minute expiry.
* A key retired from the JWK Set stops being accepted at t+300s with the
default cache, and never with a Spring cache that has no TTL.
* 25 tokens carrying an unknown kid produce 25 JWKS fetches at the issuer,
through permitAll() endpoints included.
* A hyphenated client id in an authorities-claim-expression parses as
subtraction; the SpelEvaluationException is swallowed and logged at TRACE.
* A clientScopes key in a Keycloak realm import replaces the built-in scopes
rather than adding to them.
New docs chapters 12-18. README covers both projects. Existing docs and scripts
updated for the new paths; no docs/output/ file from the first article moved, so
links in the published article still resolve.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013f7f2XZXrQ6gW3RtZE187t
52 lines
2.1 KiB
Bash
Executable File
52 lines
2.1 KiB
Bash
Executable File
#!/usr/bin/env bash
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# The claim checks that decide whether a correctly signed token is yours.
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# Usage: ./scripts/issuer-audience-demo.sh "<profiles the resource server is running with>"
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set -eu
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. "$(dirname "$0")/lib.sh"
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PROFILES="${1:-unknown}"
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head1 "resource server profiles: $PROFILES"
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head1 "1. A correct token"
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T=$(stub_token "sub=alice&aud=reports-api")
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claims "$T"
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "2. Signed by the right key, but iss says something else"
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echo "The signature verifies. The key is the same key. Only the string differs."
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T=$(stub_token "sub=alice&aud=reports-api&issuerOverride=http://localhost:9000/other")
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claims "$T"
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "3. A token minted for a different service in the same realm"
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echo "This is the one that silently works when nothing checks aud."
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T=$(stub_token "sub=alice&aud=billing-api")
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claims "$T"
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "4. Expired 90 seconds ago"
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echo "The default clock skew is 60s, so a token has to be more than a minute stale"
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echo "before JwtTimestampValidator refuses it."
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T=$(stub_token "sub=alice&aud=reports-api&issuedAgoSeconds=120&expiresInSeconds=30")
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "5. Expired 30 seconds ago - inside the default clock skew"
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T=$(stub_token "sub=alice&aud=reports-api&issuedAgoSeconds=60&expiresInSeconds=30")
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "6. typ=at+jwt, which RFC 9068 says an access token SHOULD carry"
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echo "The default validator stack contains JwtTypeValidator.jwt(), which accepts only an"
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echo "absent typ or typ=JWT. Whether this passes depends on the attyp profile."
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T=$(stub_token "sub=alice&aud=reports-api&typ=at%2Bjwt")
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claims "$T"
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call "GET /api/me" "$RS/api/me" "$T"
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head1 "7. No token at all"
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call "GET /api/me" "$RS/api/me"
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call "GET /api/public/ping" "$RS/api/public/ping"
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head1 "8. The endpoint nobody configured"
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echo "Spring Security 7 publishes RFC 9728 protected resource metadata and points the"
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echo "WWW-Authenticate challenge at it. It answers without a token."
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call "GET /.well-known/oauth-protected-resource" "$RS/.well-known/oauth-protected-resource"
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