Spring Security 7.1 JWT authentication on Spring Boot 4.1

Runnable companion for https://ankurm.com/spring-security-7-1-jwt-authentication-guide/

- login -> token issue -> OncePerRequestFilter -> SecurityContext, end to end
- HS256 and RS256 variants (RS256 publishes a real JWKS endpoint)
- the same API secured by the built-in oauth2ResourceServer().jwt(), for comparison
- 11 documentation chapters under docs/, interlinked with the code
- docs/output/ is real captured output, regenerated by scripts/run-all.sh
- 13 passing tests pinning the 401-vs-403 contract and the CSRF failure

Verified against Spring Boot 4.1.1, Spring Security 7.1.1, JDK 25.0.4.1.

scripts/resource-server-demo.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# Compares the built-in resource server with and without a token_type validator.
+# Requires two runs; see docs/09-manual-filter-vs-resource-server.md
+set -u
+BASE="${1:-http://localhost:8080}"
+LABEL="${2:-resourceserver}"
+show() {
+  local out; out=$(curl -sS -D /tmp/.h -o /tmp/.b -w '%{http_code}' "$@")
+  printf 'HTTP %s\n' "$out"
+  grep -iE '^www-authenticate:' /tmp/.h | sed 's/\r$//'
+  [ -s /tmp/.b ] && { python3 -m json.tool < /tmp/.b 2>/dev/null | head -10 || cat /tmp/.b; echo; }
+}
+hr(){ printf '\n%s\n' "--------------------------------------------------------------------------"; }
+
+echo "=========================================================================="
+echo " jwt-auth-demo - built-in resource server"
+echo " profiles: $LABEL"
+echo "=========================================================================="
+
+R=$(curl -sS -X POST "$BASE/api/auth/login" -H 'Content-Type: application/json' \
+    -d '{"username":"alice","password":"alice-password"}')
+ACCESS=$(echo "$R" | python3 -c 'import json,sys;print(json.load(sys.stdin)["accessToken"])')
+REFRESH=$(echo "$R" | python3 -c 'import json,sys;print(json.load(sys.stdin)["refreshToken"])')
+
+hr; echo "# 1. The filter chain. Note BearerTokenAuthenticationFilter in place of our"
+echo "#    hand-written JwtAuthenticationFilter - same slot, framework-owned."
+echo; show "$BASE/api/public/filters"
+
+hr; echo "# 2. Access token -> 200."; echo; show "$BASE/api/me" -H "Authorization: Bearer $ACCESS"
+
+hr; echo "# 3. Non-admin on an admin route -> 403 insufficient_scope."
+echo; show "$BASE/api/admin/stats" -H "Authorization: Bearer $ACCESS"
+
+hr; echo "# 4. REFRESH token presented as an access token."
+echo "#    This is the line to watch when comparing the two runs."
+echo; show "$BASE/api/me" -H "Authorization: Bearer $REFRESH"
+
+hr; echo "# end"