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
59 lines
2.6 KiB
Bash
Executable File
59 lines
2.6 KiB
Bash
Executable File
#!/usr/bin/env bash
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# Key rotation as three separate events, with the resource server watched in between.
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# Requires the stub issuer and a resource server pointed at it.
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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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probe() { # prints just the status code for a token
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local token="$1"
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curl -s -o /dev/null -w '%{http_code}' -H "Authorization: Bearer $token" "$RS/api/me"
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}
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head1 "resource server profiles: $PROFILES"
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curl -s -X POST "$STUB/admin/reset-counter" >/dev/null
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echo "Issuer state at the start:"; stub_state
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head1 "0. Warm the cache"
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OLD=$(stub_token "sub=alice&aud=reports-api")
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echo "token signed with $(curl -s "$STUB/admin/state" | python3 -c 'import json,sys;print(json.load(sys.stdin)["activeKid"])')"
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echo "GET /api/me -> $(probe "$OLD")"
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echo "jwks fetches so far: $(stub_fetches)"
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head1 "1. PUBLISH a second key. Nothing signs with it yet."
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NEW=$(curl -s -X POST "$STUB/admin/publish" | python3 -c 'import json,sys;print(json.load(sys.stdin)["publishedKids"][-1])')
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echo "published: $NEW"
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stub_state
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echo
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echo "The resource server has not been told. Its cached JWK Set still holds one key."
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echo "Old token still works: $(probe "$OLD")"
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echo "jwks fetches so far: $(stub_fetches) <- unchanged: nothing forced a refresh"
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head1 "2. ACTIVATE the new key. The issuer starts signing with it."
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curl -s -X POST "$STUB/admin/activate?kid=$NEW" >/dev/null
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NEWTOK=$(stub_token "sub=alice&aud=reports-api")
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echo "A token arrives whose kid is not in the cached JWK Set."
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echo "New token: $(probe "$NEWTOK")"
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echo "jwks fetches so far: $(stub_fetches) <- the unknown kid forced one"
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echo
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echo "This is the recovery path, and it works. It is also the only thing in the default"
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echo "configuration that notices a rotation, because refresh-ahead is switched off."
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head1 "3. Tokens signed with the old key are still in flight"
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echo "They were minted before the switch and have not expired yet."
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echo "Old token: $(probe "$OLD") <- still accepted, because the old key is still published"
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head1 "4. RETIRE the old key from the JWK Set"
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OLDKID=$(curl -s "$STUB/admin/state" | python3 -c 'import json,sys;print(json.load(sys.stdin)["publishedKids"][0])')
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curl -s -X POST "$STUB/admin/retire?kid=$OLDKID" >/dev/null
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echo "retired: $OLDKID"
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stub_state
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echo
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echo "The resource server's cache still contains it, so nothing changes yet."
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echo "Old token: $(probe "$OLD")"
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echo "New token: $(probe "$NEWTOK")"
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echo "jwks fetches so far: $(stub_fetches)"
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echo
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echo "How long the old key keeps working from here is decided entirely by the cache."
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echo "See retired-key-demo.sh, which runs this same step under two cache configurations."
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