chore(release): v1.0.62

Back-channel logout keys for sub, sid and jti had no issuer or client
in them, in a cache shared by every instance. A logout for user u1 in
one realm logged out u1 in another, and an equal jti in two realms
looked like a replay. Keys now carry the instance prefix. An instance
without a prefix keeps the old key.

.github/dependabot.yml

@@ -1,52 +0,0 @@
-version: 2
-updates:
-  # Maintain dependencies for GitHub Actions
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "weekly"
-      day: "monday"
-      time: "09:00"
-    open-pull-requests-limit: 5
-    commit-message:
-      prefix: "chore(deps)"
-      include: "scope"
-    labels:
-      - "dependencies"
-      - "github-actions"
-    reviewers:
-      - "lukaszraczylo"
-
-  # Maintain Go module dependencies
-  - package-ecosystem: "gomod"
-    directory: "/"
-    schedule:
-      interval: "weekly"
-      day: "monday"
-      time: "09:00"
-    open-pull-requests-limit: 10
-    commit-message:
-      prefix: "chore(deps)"
-      include: "scope"
-    labels:
-      - "dependencies"
-      - "go"
-    reviewers:
-      - "lukaszraczylo"
-    # Group patch updates together
-    groups:
-      patch-updates:
-        patterns:
-          - "*"
-        update-types:
-          - "patch"
-      minor-updates:
-        patterns:
-          - "*"
-        update-types:
-          - "minor"
-    # Ignore certain dependencies if needed
-    ignore:
-      # Example: ignore specific versions
-      # - dependency-name: "github.com/example/package"
-      #   versions: ["1.x", "2.x"]

.traefik.yml

@@ -72,6 +72,13 @@ testData:
       value: "{{.Claims.email}}"
     - name: Authorization
       value: "Bearer {{.AccessToken}}"
+    # Object/array claim as one JSON header; the claim must be whitelisted.
+    - name: X-Tenant
+      value: '{{get .Claims "tenant" | toJson}}'
+
+  # Extends the built-in claim whitelist for templated headers.
+  allowedClaims:
+    - tenant
 
   # Security headers (default profile is enabled out of the box)
   securityHeaders:

README.md

@@ -441,8 +441,34 @@ headers:
 Rendering the whole context (`{{.}}`, `{{$}}`), the whole claims map
 (`{{.Claims}}`), or any non-listed claim is rejected — this prevents a template
 from accidentally forwarding raw tokens or unlisted claims. `range`/`with` must
-target a specific listed claim (e.g. `{{range .Claims.groups}}`); `get`/`default`
-are the only functions allowed.
+target a specific listed claim (e.g. `{{range .Claims.groups}}`); `get`, `default`
+and `toJson` are the only functions allowed.
+
+### Forwarding an object claim as JSON
+
+`toJson` serializes a claim (object, array or scalar) to compact JSON, so a
+backend can parse the whole claim itself instead of the middleware flattening
+it into one header per key:
+
+```yaml
+allowedClaims:
+  - tenant
+headers:
+  - name: X-Tenant
+    value: '{{get .Claims "tenant" | toJson}}'   # {"id":"t-1","plan":"pro"}
+  - name: X-Groups
+    value: "{{toJson .Claims.groups}}"           # ["admin","users"]
+```
+
+- The claim must be on the whitelist (built-in or `allowedClaims`).
+  `{{toJson .Claims}}`, `{{toJson .}}` and non-listed claims are rejected.
+- An absent or empty claim skips the header instead of sending `""`.
+- Control characters are JSON-escaped, so a claim cannot inject extra header
+  lines.
+- A rendered value over 8192 bytes, or one with bidi-override characters, is
+  dropped. The oversize case is logged at error level (header name only, never
+  the value); keep the claim small, since proxies commonly cap headers at
+  8-16 KB.
 
 > **File-provider users: escape the braces.** Traefik's file provider runs
 > every dynamic configuration file through Go templating before the plugin

audience_sentinel_test.go

@@ -0,0 +1,24 @@
+package traefikoidc
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+)
+
+// Only a real audience mismatch may select the lenient-audience path; an
+// error text that merely embeds the attacker-chosen kid must not.
+func TestAudienceErrorClassifiedBySentinel(t *testing.T) {
+	if !errors.Is(fmt.Errorf("standard claim verification failed: %w", verifyAudience("x", "y")), errInvalidAudience) {
+		t.Fatal("audience mismatch not recognized through wrapping")
+	}
+	if errors.Is(verifyAudience("y", "y"), errInvalidAudience) {
+		t.Fatal("matching audience classified as mismatch")
+	}
+	for _, kid := range []string{"audience", "invalid audience"} {
+		err := fmt.Errorf("failed to get public key: no matching public key found for kid: %s", kid)
+		if errors.Is(err, errInvalidAudience) {
+			t.Errorf("kid %q fooled the audience classifier", kid)
+		}
+	}
+}

bearer_auth.go

@@ -223,6 +223,9 @@ func headerInjectionRuneReason(r rune) string {
 	return ""
 }
 
+// headerReasonTooLong is the headerValueReason result for an over-long value.
+const headerReasonTooLong = "exceeds max length"
+
 // headerValueReason reports why value is unsafe to forward as a free-form HTTP
 // header value, or "" if acceptable. It rejects values over maxLen (maxLen<=0
 // disables the check) and values containing control or bidi-override runes, but
@@ -230,7 +233,7 @@ func headerInjectionRuneReason(r rune) string {
 // never includes the value, so it is safe to log.
 func headerValueReason(value string, maxLen int) string {
 	if maxLen > 0 && len(value) > maxLen {
-		return "exceeds max length"
+		return headerReasonTooLong
 	}
 	for _, r := range value {
 		if reason := headerInjectionRuneReason(r); reason != "" {
@@ -368,6 +371,11 @@ func enforceIatAge(claims map[string]interface{}, maxAge time.Duration) *bearerE
 	if time.Since(iat) > maxAge {
 		return newBearerError(bearerErrInvalidToken, "token iat outside age bound")
 	}
+	// The opaque introspection path never runs jwt.Verify, so a future iat
+	// would otherwise defeat the age bound for the token's whole lifetime.
+	if time.Until(iat) > ClockSkewToleranceFuture {
+		return newBearerError(bearerErrInvalidToken, "token iat in the future")
+	}
 	return nil
 }
 
@@ -550,9 +558,10 @@ func clientIPForBearer(req *http.Request) string {
 	}
 	host, _, err := net.SplitHostPort(req.RemoteAddr)
 	if err != nil {
-		return req.RemoteAddr
+		host = req.RemoteAddr
 	}
-	return host
+	// One IPv6 /64 shares a key, so a single host cannot mint 2^64 entries.
+	return limiterKey(host)
 }
 
 // --- Bearer auth entrypoint ---

bearer_failure_ipv6_test.go

@@ -0,0 +1,24 @@
+package traefikoidc
+
+import (
+	"net/http/httptest"
+	"testing"
+)
+
+// Addresses in one IPv6 /64 must share one failure-tracker key.
+func TestClientIPForBearerCollapsesIPv6Prefix(t *testing.T) {
+	key := func(addr string) string {
+		r := httptest.NewRequest("GET", "/", nil)
+		r.RemoteAddr = addr
+		return clientIPForBearer(r)
+	}
+	if a, b := key("[2001:db8:1:2::1]:1"), key("[2001:db8:1:2:ffff::9]:2"); a != b {
+		t.Fatalf("same /64 got different keys: %q vs %q", a, b)
+	}
+	if a, b := key("[2001:db8:1:2::1]:1"), key("[2001:db8:1:3::1]:1"); a == b {
+		t.Fatalf("different /64 shared key %q", a)
+	}
+	if got := key("192.0.2.7:80"); got != "192.0.2.7" {
+		t.Fatalf("ipv4 key = %q", got)
+	}
+}

chunk_validation_pin_test.go

@@ -0,0 +1,94 @@
+package traefikoidc
+
+import (
+	"strings"
+	"testing"
+)
+
+// These tests pin the token-content validators' results, including for
+// multi-byte UTF-8 input, so their loops can be rewritten for yaegi (where
+// ranging over a string allocates O(n²)) without changing behavior.
+
+func TestDetectRepeatedCharactersPinned(t *testing.T) {
+	cm := NewChunkManager(NewLogger(""))
+	cases := []struct {
+		name    string
+		token   string
+		wantErr string
+	}{
+		{"short token skipped", "aaaaaaaaa", ""},
+		{"varied ascii", "abcdefghijklmnopqrstuvwxyz0123456789", ""},
+		{"20 repeats allowed", strings.Repeat("a", 20) + strings.Repeat("bcdefghij", 4), ""},
+		{"21 repeats rejected", strings.Repeat("a", 21) + strings.Repeat("bcdefghij", 4), "excessive repeated characters (21 consecutive)"},
+		{"multibyte run counted per rune", strings.Repeat("é", 21) + strings.Repeat("bcdefghij", 4), "excessive repeated characters (21 consecutive)"},
+		// Rune counts are divided by the byte length, so a multi-byte rune
+		// cannot reach the 70% threshold. Pinned as-is.
+		{"multibyte frequency divides by byte length", strings.Repeat("éééx", 8), ""},
+		{"ascii frequency over 70%", strings.Repeat("aaaab", 8), "suspicious character frequency (char 'a'"},
+		{"multibyte mixed passes", "日本語テキストabcdefghijklmnopqrstuvwxyz", ""},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := cm.detectRepeatedCharacters(tc.token, AccessTokenConfig)
+			assertPinnedErr(t, err, tc.wantErr)
+		})
+	}
+}
+
+func TestValidateJWTFormatPinned(t *testing.T) {
+	cm := NewChunkManager(NewLogger(""))
+	cases := []struct {
+		name    string
+		token   string
+		wantErr string
+	}{
+		{"valid base64url parts", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdWIiOiJ4In0", "c2lnbmF0dXJlLXZhbHVl"), ""},
+		{"padding allowed", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdWIiOiJ4In0=", "c2lnbmF0dXJl"), ""},
+		{"plus rejected", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzd+IiOiJ4In0", "c2lnbmF0dXJl"), "invalid base64url character in part 1"},
+		{"multibyte rejected", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdé", "c2lnbmF0dXJl"), "invalid base64url character in part 1"},
+		{"control char rejected", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdWIiOiJ4In0", "c2ln\x01bmF0"), "invalid base64url character in part 2"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := cm.validateJWTFormat(tc.token, "access")
+			assertPinnedErr(t, err, tc.wantErr)
+		})
+	}
+}
+
+func TestValidateTokenSanitizationPinned(t *testing.T) {
+	cm := NewChunkManager(NewLogger(""))
+	cases := []struct {
+		name    string
+		token   string
+		wantErr string
+	}{
+		{"clean jwt", jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdWIiOiJ4In0", "c2lnbmF0dXJl"), ""},
+		{"multibyte allowed", jwtLike("eyJhbGciOiJSUzI1NiJ9", "日本語", "c2lnbmF0dXJl"), ""},
+		{"control char byte offset", "abcé\x01def", "control character at position 5"},
+		{"delete char", "abcdef\x7fgh", "control character at position 6"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := cm.validateTokenSanitization(tc.token, AccessTokenConfig)
+			assertPinnedErr(t, err, tc.wantErr)
+		})
+	}
+}
+
+// jwtLike joins parts with dots at runtime; JWT-shaped literals trip the
+// pre-commit secret scanner.
+func jwtLike(parts ...string) string { return strings.Join(parts, ".") }
+
+func assertPinnedErr(t *testing.T, err error, want string) {
+	t.Helper()
+	if want == "" {
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		return
+	}
+	if err == nil || !strings.Contains(err.Error(), want) {
+		t.Fatalf("error = %v, want containing %q", err, want)
+	}
+}

cmd/yaegicheck/main.go

@@ -139,6 +139,7 @@ func main() {
 	runCheck("middleware-erraborthandler-aborts-under-yaegi", checkErrAbortHandlerAbortsUnderYaegi)
 	runCheck("fix17-setifabsent-claims-once", checkSetIfAbsentUnderYaegi)
 	runCheck("issue162-websocket-forwards-header-templates", checkIssue162WebSocketHeaderTemplates)
+	runCheck("tojson-header-template", checkToJsonHeaderTemplate)
 	runCheck("streaming-refresh-revoked-grant-rejected", checkStreamingRefreshRevokedGrant)
 	fmt.Println("OK: all yaegi regression checks passed")
 }
@@ -807,6 +808,99 @@ func checkIssue162WebSocketHeaderTemplates() (string, error) {
 	return "", nil
 }
 
+// checkToJsonHeaderTemplate pins the toJson template helper under the
+// interpreter: its (string, error) closure, json.Marshal of an object claim,
+// the nil/absent-claim skip and the validator's rejection of a whole-claims dump.
+func checkToJsonHeaderTemplate() (string, error) {
+	discovery := servers.NewOIDCServer(nil)
+	defer discovery.Close()
+
+	cfg := oidc.CreateConfig()
+	cfg.ProviderURL = discovery.URL
+	cfg.ClientID = "yaegi-check-tojson-client"
+	cfg.ClientSecret = "yaegi-check-tojson-secret"
+	cfg.CallbackURL = "/oauth2/callback"
+	cfg.SessionEncryptionKey = "0123456789abcdef0123456789abcdef"
+	cfg.AllowedClaims = []string{"tenant"}
+	cfg.Headers = []oidc.TemplatedHeader{
+		{Name: "X-Tenant", Value: `{{ get .Claims "tenant" | toJson }}`},
+		{Name: "X-Groups", Value: "{{ toJson .Claims.groups }}"},
+		{Name: "X-Missing", Value: "{{ toJson .Claims.department }}"},
+	}
+	if err := cfg.Validate(); err != nil {
+		return "", fmt.Errorf("toJson headers must validate: %w", err)
+	}
+
+	bad := oidc.CreateConfig()
+	*bad = *cfg
+	bad.Headers = []oidc.TemplatedHeader{{Name: "X-All", Value: "{{ toJson .Claims }}"}}
+	if err := bad.Validate(); err == nil {
+		return "", fmt.Errorf("toJson of the whole claims map must fail validation")
+	}
+
+	var seen http.Header
+	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		seen = r.Header.Clone()
+	})
+	h, err := oidc.New(context.Background(), next, cfg, "yaegi-check-tojson")
+	if err != nil {
+		return "", fmt.Errorf("New: %w", err)
+	}
+	if closer, ok := h.(interface{ Close() error }); ok {
+		defer closer.Close()
+	}
+
+	sm, err := oidc.NewSessionManager(cfg.SessionEncryptionKey, cfg.ForceHTTPS, cfg.CookieDomain, cfg.CookiePrefix, time.Duration(cfg.SessionMaxAge)*time.Second, oidc.NewLogger("error"))
+	if err != nil {
+		return "", fmt.Errorf("NewSessionManager: %w", err)
+	}
+	defer sm.Shutdown()
+
+	setupReq := httptest.NewRequest("GET", "/ws", nil)
+	session, err := sm.GetSession(setupReq)
+	if err != nil {
+		return "", fmt.Errorf("GetSession: %w", err)
+	}
+	if err := session.SetAuthenticated(true); err != nil {
+		return "", fmt.Errorf("SetAuthenticated: %w", err)
+	}
+	session.SetUserIdentifier("[email protected]")
+	b64 := base64.RawURLEncoding.EncodeToString
+	sig := make([]byte, 32)
+	for i := range sig {
+		sig[i] = byte(i + 1)
+	}
+	session.SetIDToken(b64([]byte(`{"alg":"RS256","typ":"JWT"}`)) + "." + b64([]byte(`{"tenant":{"id":"t-1","plan":"pro"},"groups":["a","b"]}`)) + "." + b64(sig))
+	rec := httptest.NewRecorder()
+	if err := session.Save(setupReq, rec); err != nil {
+		return "", fmt.Errorf("session.Save: %w", err)
+	}
+	session.ReturnToPool()
+
+	req := httptest.NewRequest("GET", "/ws", nil)
+	for _, c := range rec.Result().Cookies() {
+		req.AddCookie(c)
+	}
+	req.Header.Set("Upgrade", "websocket")
+	req.Header.Set("Connection", "Upgrade")
+	rw := httptest.NewRecorder()
+	h.ServeHTTP(rw, req)
+
+	if seen == nil {
+		return "", fmt.Errorf("next was not reached (status %d)", rw.Code)
+	}
+	if got, want := seen.Get("X-Tenant"), `{"id":"t-1","plan":"pro"}`; got != want {
+		return "", fmt.Errorf("X-Tenant = %q, want %q", got, want)
+	}
+	if got, want := seen.Get("X-Groups"), `["a","b"]`; got != want {
+		return "", fmt.Errorf("X-Groups = %q, want %q", got, want)
+	}
+	if got := seen.Get("X-Missing"); got != "" {
+		return "", fmt.Errorf("X-Missing = %q, want header skipped", got)
+	}
+	return "", nil
+}
+
 // checkStreamingRefreshRevokedGrant drives streamingRefresh under the
 // interpreter through the real RefreshCoordinator and token exchanger: an
 // expired session whose refresh the IdP answers with invalid_grant must get

combined_payload_pool_test.go

@@ -0,0 +1,45 @@
+package traefikoidc
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestDecompressCombinedPayloadReusesReaders(t *testing.T) {
+	var readers sync.Pool
+	first, err := compressCombinedPayload(&combinedSessionPayload{Ui: "[email protected]"})
+	if err != nil {
+		t.Fatalf("compress first: %v", err)
+	}
+	second, err := compressCombinedPayload(&combinedSessionPayload{Ui: "[email protected]"})
+	if err != nil {
+		t.Fatalf("compress second: %v", err)
+	}
+
+	cases := []struct {
+		name     string
+		input    string
+		wantUser string
+		wantErr  bool
+	}{
+		{"first payload", first, "[email protected]", false},
+		{"corrupt payload rejected", "bm90LWd6aXA=", "", true},
+		{"second payload after corrupt one", second, "[email protected]", false},
+		{"first payload again", first, "[email protected]", false},
+	}
+	for _, tc := range cases {
+		got, err := decompressCombinedPayload(tc.input, &readers)
+		if tc.wantErr {
+			if err == nil {
+				t.Fatalf("%s: expected error", tc.name)
+			}
+			continue
+		}
+		if err != nil {
+			t.Fatalf("%s: %v", tc.name, err)
+		}
+		if got.Ui != tc.wantUser {
+			t.Fatalf("%s: user = %q, want %q", tc.name, got.Ui, tc.wantUser)
+		}
+	}
+}

content_valid_cache_test.go

@@ -0,0 +1,67 @@
+package traefikoidc
+
+import (
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestContentValidCache(t *testing.T) {
+	cm := NewChunkManager(NewLogger(""))
+	t.Cleanup(cm.Shutdown)
+	now := time.Now()
+	valid := tokenWithGroups(t, map[string]interface{}{"sub": "a", "exp": float64(now.Add(time.Hour).Unix()), "iat": float64(now.Unix())})
+	futureIat := tokenWithGroups(t, map[string]interface{}{"sub": "b", "exp": float64(now.Add(2 * time.Hour).Unix()), "iat": float64(now.Add(time.Hour).Unix())})
+	badContent := jwtLike("eyJhbGciOiJSUzI1NiJ9", "eyJzdWIiOiJ4In0", "c2ln\x01bmF0dXJlLXZhbHVl")
+
+	t.Run("valid token passes twice and is cached", func(t *testing.T) {
+		for i := 0; i < 2; i++ {
+			if res := cm.validateToken(valid, AccessTokenConfig); res.Error != nil {
+				t.Fatalf("pass %d: %v", i, res.Error)
+			}
+		}
+		if _, ok := cm.cachedTokenTimes(contentValidKey(valid, AccessTokenConfig)); !ok {
+			t.Fatal("valid token was not cached")
+		}
+	})
+	t.Run("cache is per token type", func(t *testing.T) {
+		if _, ok := cm.cachedTokenTimes(contentValidKey(valid, IDTokenConfig)); ok {
+			t.Fatal("access-token entry leaked into the ID-token key")
+		}
+	})
+	t.Run("time checks still run on a cache hit", func(t *testing.T) {
+		cm.markContentValid(contentValidKey(futureIat, AccessTokenConfig), cm.tokenTimesOf(futureIat))
+		res := cm.validateToken(futureIat, AccessTokenConfig)
+		if res.Error == nil || !strings.Contains(res.Error.Error(), "issued in future") {
+			t.Fatalf("error = %v, want issued-in-future through the content cache", res.Error)
+		}
+	})
+	t.Run("cache hit uses the stored claims", func(t *testing.T) {
+		other := tokenWithGroups(t, map[string]interface{}{"sub": "c", "exp": float64(now.Add(time.Hour).Unix()), "iat": float64(now.Unix())})
+		future := now.Add(time.Hour)
+		cm.markContentValid(contentValidKey(other, AccessTokenConfig), tokenTimes{jwt: true, iat: &future})
+		res := cm.validateToken(other, AccessTokenConfig)
+		if res.Error == nil || !strings.Contains(res.Error.Error(), "issued in future") {
+			t.Fatalf("error = %v, want the cached iat to drive the freshness check", res.Error)
+		}
+	})
+	t.Run("invalid content never cached", func(t *testing.T) {
+		if res := cm.validateToken(badContent, AccessTokenConfig); res.Error == nil {
+			t.Fatal("control character accepted")
+		}
+		if _, ok := cm.cachedTokenTimes(contentValidKey(badContent, AccessTokenConfig)); ok {
+			t.Fatal("invalid token was cached")
+		}
+	})
+	t.Run("cache stays bounded", func(t *testing.T) {
+		for i := 0; i < contentValidCacheMax+10; i++ {
+			cm.markContentValid(contentValidKey(strings.Repeat("x", i%7)+string(rune('a'+i%26))+strings.Repeat("y", i/26), AccessTokenConfig), tokenTimes{})
+		}
+		cm.contentMu.Lock()
+		n := len(cm.contentValid)
+		cm.contentMu.Unlock()
+		if n > contentValidCacheMax {
+			t.Fatalf("cache size %d exceeds %d", n, contentValidCacheMax)
+		}
+	})
+}

docs/CONFIGURATION.md

@@ -571,7 +571,7 @@ be emitted — the standard OIDC claims plus common provider claims (`email`,
 `phone_number`, `email_verified`, `updated_at`; the authoritative list is
 `safeClaimsFields` in `template_validation.go`). Rejected: rendering the whole
 context (`{{.}}`, `{{$}}`) or the whole claims map (`{{.Claims}}`), any claim not
-on the list, functions other than `get`/`default`, and `range`/`with` that do not
+on the list, functions other than `get`/`default`/`toJson`, and `range`/`with` that do not
 target a specific listed claim (e.g. `{{range .Claims}}` is rejected; `{{range
 .Claims.groups}}` is allowed).
 
@@ -592,6 +592,21 @@ Listed names apply to both direct access (`{{.Claims.employee_id}}`) and
 claim (e.g. `realm_access.roles`) are already accessible without listing them
 individually.
 
+**`toJson`** forwards an object or array claim as one JSON header:
+
+```yaml
+allowedClaims:
+  - tenant
+headers:
+  - name: "X-Tenant"
+    value: "{{get .Claims \"tenant\" | toJson}}"
+```
+
+It only serializes values the template can already reach, so the whitelist
+still applies; `{{toJson .Claims}}` is rejected. Control characters are
+JSON-escaped, and values over 8192 bytes or with bidi-override characters are
+dropped; an oversize value is logged at error level (header name only).
+
 ---
 
 ## Security Headers

header_templates_owned_test.go

@@ -0,0 +1,54 @@
+package traefikoidc
+
+import (
+	"net/http/httptest"
+	"testing"
+	"text/template"
+)
+
+func ownedHeaderOIDC(t *testing.T, names ...string) *TraefikOidc {
+	t.Helper()
+	m := map[string]*template.Template{}
+	for _, n := range names {
+		m[n] = template.Must(template.New(n).Option("missingkey=zero").Parse("{{.Claims.tenant}}"))
+	}
+	return &TraefikOidc{logger: NewLogger("error"), headerTemplates: m}
+}
+
+// A templated header the middleware owns must never carry a client value:
+// an optional claim that renders empty must leave the header absent.
+func TestTemplatedHeaderDropsClientSpoof(t *testing.T) {
+	o := ownedHeaderOIDC(t, "X-Tenant")
+	req := httptest.NewRequest("GET", "/", nil)
+	req.Header.Set("X-Tenant", "admin-corp")
+	o.applyHeaderTemplates(req, &principal{Claims: map[string]interface{}{"sub": "u"}})
+	if got := req.Header.Get("X-Tenant"); got != "" {
+		t.Fatalf("client-supplied X-Tenant reached the backend: %q", got)
+	}
+}
+
+func TestTemplatedHeaderRenderedValueWins(t *testing.T) {
+	o := ownedHeaderOIDC(t, "X-Tenant")
+	req := httptest.NewRequest("GET", "/", nil)
+	req.Header.Set("X-Tenant", "evil")
+	o.applyHeaderTemplates(req, &principal{Claims: map[string]interface{}{"tenant": "acme"}})
+	if got := req.Header.Get("X-Tenant"); got != "acme" {
+		t.Fatalf("X-Tenant = %q, want acme", got)
+	}
+}
+
+// Identity headers are injected before templates run; an empty render must
+// not clobber them, and Authorization stays as received.
+func TestTemplatedHeaderKeepsIdentityAndAuthorization(t *testing.T) {
+	o := ownedHeaderOIDC(t, "X-Forwarded-User", "Authorization")
+	req := httptest.NewRequest("GET", "/", nil)
+	req.Header.Set("X-Forwarded-User", "alice")
+	req.Header.Set("Authorization", "Bearer abc")
+	o.applyHeaderTemplates(req, &principal{Claims: map[string]interface{}{"sub": "u"}})
+	if got := req.Header.Get("X-Forwarded-User"); got != "alice" {
+		t.Fatalf("identity header clobbered: %q", got)
+	}
+	if got := req.Header.Get("Authorization"); got != "Bearer abc" {
+		t.Fatalf("Authorization changed: %q", got)
+	}
+}

helpers.go

@@ -13,6 +13,7 @@ import (
 	"net/http/cookiejar"
 	"net/url"
 	"strings"
+	"sync/atomic"
 	"time"
 )
 
@@ -293,10 +294,37 @@ func extractClaims(tokenString string) (map[string]interface{}, error) {
 // TokenCache provides a specialized cache for JWT tokens and their parsed claims.
 // It wraps the UniversalCache with token-specific operations.
 type TokenCache struct {
+	// ns scopes entries to one middleware instance (issuer|client|audience)
+	// so a verdict cached by one instance cannot satisfy another.
+	ns atomic.Value
 	// cache is the underlying universal cache implementation
 	cache *UniversalCache
 }
 
+// SetNamespace sets the verification context that scopes this cache's keys.
+func (tc *TokenCache) SetNamespace(ns string) {
+	if tc == nil {
+		return
+	}
+	tc.ns.Store(ns)
+}
+
+// Namespace returns the scope set by SetNamespace, or "" when none is set.
+func (tc *TokenCache) Namespace() string {
+	if tc == nil {
+		return ""
+	}
+	ns, _ := tc.ns.Load().(string)
+	return ns
+}
+
+func (tc *TokenCache) key(token string) string {
+	if ns, _ := tc.ns.Load().(string); ns != "" {
+		return "t-" + ns + "|" + token
+	}
+	return "t-" + token
+}
+
 // NewTokenCache creates and initializes a new TokenCache.
 // It uses the global cache manager to ensure singleton behavior.
 func NewTokenCache() *TokenCache {
@@ -313,7 +341,7 @@ func NewTokenCache() *TokenCache {
 //   - claims: Parsed claims from the token
 //   - expiration: The duration for which the cache entry should be valid
 func (tc *TokenCache) Set(token string, claims map[string]interface{}, expiration time.Duration) {
-	token = "t-" + token
+	token = tc.key(token)
 	_ = tc.cache.Set(token, claims, expiration) // Safe to ignore: cache failures are non-critical
 }
 
@@ -325,7 +353,7 @@ func (tc *TokenCache) Set(token string, claims map[string]interface{}, expiratio
 //   - map[string]interface{}: The cached claims if found
 //   - A boolean indicating whether the token was found in the cache (true if found, false otherwise)
 func (tc *TokenCache) Get(token string) (map[string]interface{}, bool) {
-	token = "t-" + token
+	token = tc.key(token)
 	value, found := tc.cache.Get(token)
 	if !found {
 		return nil, false
@@ -338,7 +366,7 @@ func (tc *TokenCache) Get(token string) (map[string]interface{}, bool) {
 // Parameters:
 //   - token: The raw token string to remove from the cache
 func (tc *TokenCache) Delete(token string) {
-	token = "t-" + token
+	token = tc.key(token)
 	tc.cache.Delete(token)
 }
 

host_canon_test.go

@@ -0,0 +1,25 @@
+package traefikoidc
+
+import "testing"
+
+func TestValidateHostCanonicalForms(t *testing.T) {
+	o := &TraefikOidc{}
+	blocked := []string{
+		"localhost.", "LOCALHOST.", "metadata.google.internal.", "metadata.google.internal",
+		"169.254.169.254.", "fe80::1%eth0", "[fe80::1]", "::1",
+	}
+	for _, h := range blocked {
+		if err := o.validateHost(h); err == nil {
+			t.Errorf("validateHost(%q) = nil, want blocked", h)
+		}
+	}
+	allowed := []string{"idp.example.com", "idp.example.com.", "2606:4700::1111"}
+	for _, h := range allowed {
+		if err := o.validateHost(h); err != nil {
+			t.Errorf("validateHost(%q) = %v, want allowed", h, err)
+		}
+	}
+	if !isLoopbackHost("localhost.") {
+		t.Error("isLoopbackHost(localhost.) = false")
+	}
+}

hunt_20261015_regression_test.go

@@ -0,0 +1,238 @@
+package traefikoidc
+
+import (
+	"context"
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestEnhanceSessionSecurity_CaseVariantForwardedHostStaysHostScoped(t *testing.T) {
+	cases := []struct {
+		name string
+		xfh  string
+	}{
+		{name: "exact-case parent", xfh: "corp.example.com"},
+		{name: "upper-case parent", xfh: "CORP.example.com"},
+		{name: "mixed-case parent", xfh: "Corp.Example.COM"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			sm := createTestSessionManager(t)
+			t.Cleanup(func() { _ = sm.Shutdown() })
+			req := httptest.NewRequest(http.MethodGet, "https://app.corp.example.com/", nil)
+			req.Host = "app.corp.example.com"
+			req.Header.Set("X-Forwarded-Host", tc.xfh)
+			opts := sm.EnhanceSessionSecurity(nil, req)
+			if opts.Domain != "app.corp.example.com" {
+				t.Fatalf("Domain = %q, want host-scoped app.corp.example.com", opts.Domain)
+			}
+		})
+	}
+
+	t.Run("case-variant forwarded host equal to serving host is kept", func(t *testing.T) {
+		sm := createTestSessionManager(t)
+		t.Cleanup(func() { _ = sm.Shutdown() })
+		req := httptest.NewRequest(http.MethodGet, "https://internal.svc/", nil)
+		req.Host = "internal.svc"
+		req.Header.Set("X-Forwarded-Host", "App.Example.com")
+		opts := sm.EnhanceSessionSecurity(nil, req)
+		if opts.Domain != "app.example.com" {
+			t.Fatalf("Domain = %q, want app.example.com", opts.Domain)
+		}
+	})
+}
+
+func TestEnforceIatAge_RejectsFutureIat(t *testing.T) {
+	const maxAge = 24 * time.Hour
+	now := time.Now()
+	cases := []struct {
+		name    string
+		iat     time.Time
+		wantErr bool
+	}{
+		{name: "now", iat: now},
+		{name: "within future skew", iat: now.Add(ClockSkewToleranceFuture / 2)},
+		{name: "one hour ahead", iat: now.Add(time.Hour), wantErr: true},
+		{name: "just beyond skew", iat: now.Add(ClockSkewToleranceFuture + 10*time.Second), wantErr: true},
+		{name: "older than max age", iat: now.Add(-48 * time.Hour), wantErr: true},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := enforceIatAge(map[string]interface{}{"iat": float64(tc.iat.Unix())}, maxAge)
+			if (err != nil) != tc.wantErr {
+				t.Fatalf("enforceIatAge err = %v, wantErr %v", err, tc.wantErr)
+			}
+		})
+	}
+}
+
+func TestJWKCache_CooldownServesParsedEntryWithoutReparse(t *testing.T) {
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatalf("keygen: %v", err)
+	}
+	c := NewJWKCache()
+	url := fmt.Sprintf("https://jwks.invalid/%d", time.Now().UnixNano())
+	// The raw set is empty, so only the pre-parsed entry can satisfy the lookup.
+	_ = c.cache.SetLocal(url, &JWKSet{}, time.Hour)
+	_ = c.cache.SetLocal(url+parsedKeysSuffix, &parsedJWKS{keys: map[string]crypto.PublicKey{"k1": &priv.PublicKey}}, time.Hour)
+	c.lastSignatureRefresh[url] = time.Now()
+
+	got, err := c.getPublicKeyFresh(context.Background(), url, "k1", http.DefaultClient)
+	if err != nil {
+		t.Fatalf("getPublicKeyFresh: %v", err)
+	}
+	if got != crypto.PublicKey(&priv.PublicKey) {
+		t.Fatal("cooldown branch did not serve the cached parsed key")
+	}
+}
+
+func TestFrontchannelLogout_FloodCannotEvictSignedMarkers(t *testing.T) {
+	cache := &CacheInterfaceWrapper{cache: NewUniversalCache(UniversalCacheConfig{
+		Type:             CacheTypeSession,
+		MaxSize:          5000,
+		DefaultTTL:       sessionInvalidationTTL,
+		Logger:           NewLogger("error"),
+		SkipAutoCleanup:  true,
+		MonotonicMarkers: true,
+	})}
+	oidc := &TraefikOidc{
+		logger:                   NewLogger("error"),
+		enableFrontchannelLogout: true,
+		sessionInvalidationCache: cache,
+		issuerURL:                "https://idp.example.com",
+	}
+	t.Cleanup(func() { _ = cache.cache.Close() })
+
+	if err := oidc.invalidateSession("", "real-subject"); err != nil {
+		t.Fatalf("invalidateSession: %v", err)
+	}
+	if err := oidc.checkAndMarkLogoutJTIProcessed("real-jti", time.Now().Unix()); err != nil {
+		t.Fatalf("mark jti: %v", err)
+	}
+
+	for i := 0; i < 6000; i++ {
+		req := httptest.NewRequest(http.MethodGet, fmt.Sprintf("/fc?iss=https://idp.example.com&sid=flood-%d", i), nil)
+		rw := httptest.NewRecorder()
+		oidc.handleFrontchannelLogout(rw, req)
+		if rw.Code != http.StatusOK {
+			t.Fatalf("flood request %d: status %d", i, rw.Code)
+		}
+	}
+
+	if _, ok := cache.Get(oidc.buildSessionInvalidationKey("sub", "real-subject")); !ok {
+		t.Error("backchannel sub marker evicted by front-channel flood")
+	}
+	if err := oidc.checkAndMarkLogoutJTIProcessed("real-jti", time.Now().Unix()); err == nil {
+		t.Error("jti replay marker evicted by front-channel flood: replay accepted")
+	}
+	held := 0
+	for i := 0; i < 6000; i++ {
+		if _, ok := cache.Get(oidc.buildSessionInvalidationKey("sid", fmt.Sprintf("flood-%d", i))); ok {
+			held++
+		}
+	}
+	if held > maxFrontchannelMarkers {
+		t.Errorf("front-channel markers held = %d, want <= %d", held, maxFrontchannelMarkers)
+	}
+	if _, ok := cache.Get(oidc.buildSessionInvalidationKey("sid", "flood-5999")); !ok {
+		t.Error("most recent front-channel marker must remain")
+	}
+}
+
+func TestMarkerQuota_Admit(t *testing.T) {
+	var q markerQuota
+	if got := q.admit("a", 2); got != "" {
+		t.Errorf("admit a = %q, want none", got)
+	}
+	if got := q.admit("a", 2); got != "" {
+		t.Errorf("re-admit a = %q, want none", got)
+	}
+	if got := q.admit("b", 2); got != "" {
+		t.Errorf("admit b = %q, want none", got)
+	}
+	if got := q.admit("c", 2); got != "a" {
+		t.Errorf("admit c evicted %q, want a", got)
+	}
+}
+
+func TestServeHTTP_InitWaitQueueFullFailsFast(t *testing.T) {
+	oidc := &TraefikOidc{
+		logger:                       NewLogger("error"),
+		initComplete:                 make(chan struct{}),
+		sessionManager:               createTestSessionManager(t),
+		firstRequestStarted:          1,
+		metadataRefreshStartedAtomic: 1,
+	}
+	oidc.initWaiters = maxInitWaiters
+
+	rw := httptest.NewRecorder()
+	start := time.Now()
+	oidc.ServeHTTP(rw, httptest.NewRequest(http.MethodGet, "/protected", nil))
+
+	if rw.Code != http.StatusServiceUnavailable {
+		t.Fatalf("status = %d, want 503", rw.Code)
+	}
+	if rw.Header().Get("Retry-After") == "" {
+		t.Error("missing Retry-After header")
+	}
+	if time.Since(start) > 5*time.Second {
+		t.Errorf("rejected after %v, want immediate", time.Since(start))
+	}
+	if oidc.initWaiters != maxInitWaiters {
+		t.Errorf("initWaiters = %d, want unchanged %d", oidc.initWaiters, maxInitWaiters)
+	}
+}
+
+func TestServeHTTP_InitWaiterReleasedOnCancel(t *testing.T) {
+	oidc := &TraefikOidc{
+		logger:                       NewLogger("error"),
+		initComplete:                 make(chan struct{}),
+		sessionManager:               createTestSessionManager(t),
+		firstRequestStarted:          1,
+		metadataRefreshStartedAtomic: 1,
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	req := httptest.NewRequest(http.MethodGet, "/protected", nil).WithContext(ctx)
+	oidc.ServeHTTP(httptest.NewRecorder(), req)
+	if oidc.initWaiters != 0 {
+		t.Fatalf("initWaiters = %d after canceled wait, want 0", oidc.initWaiters)
+	}
+}
+
+func TestCleanupOldCookies_CapsDeletionHeaders(t *testing.T) {
+	sm, err := NewSessionManager("test-encryption-key-32-bytes-long!!", false, "cookie.example.com", "testpref", 0, newNoOpLogger())
+	if err != nil {
+		t.Fatalf("session manager: %v", err)
+	}
+	t.Cleanup(func() { _ = sm.Shutdown() })
+
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	req.Host = "a.b.example.com"
+	for i := 0; i < 180; i++ {
+		req.AddCookie(&http.Cookie{Name: fmt.Sprintf("testpref_%d", i), Value: "x"})
+	}
+	rw := httptest.NewRecorder()
+	sm.CleanupOldCookies(rw, req)
+
+	got := len(rw.Result().Cookies())
+	if got == 0 {
+		t.Fatal("expected deletion cookies for the first wave")
+	}
+	if limit := maxCleanupCookies * 4; got > limit {
+		t.Fatalf("deletion Set-Cookie headers = %d, want <= %d", got, limit)
+	}
+	for _, c := range rw.Result().Cookies() {
+		if !strings.HasPrefix(c.Name, "testpref_") {
+			t.Errorf("unexpected deletion cookie %q", c.Name)
+		}
+	}
+}

id_token_memo_test.go

@@ -0,0 +1,50 @@
+package traefikoidc
+
+import (
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestIDTokenMemoFollowsStoredToken(t *testing.T) {
+	sm, err := NewSessionManager("0123456789abcdef0123456789abcdef", false, "", "", time.Hour, NewLogger("error"))
+	if err != nil {
+		t.Fatalf("NewSessionManager: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := sm.Shutdown(); err != nil {
+			t.Errorf("Shutdown: %v", err)
+		}
+	})
+	future := float64(time.Now().Add(time.Hour).Unix())
+	first := tokenWithGroups(t, map[string]interface{}{"sub": "first", "exp": future})
+	second := tokenWithGroups(t, map[string]interface{}{"sub": "second", "exp": future})
+
+	session, err := sm.GetSession(httptest.NewRequest("GET", "/", nil))
+	if err != nil {
+		t.Fatalf("GetSession: %v", err)
+	}
+	steps := []struct {
+		name  string
+		write func()
+		want  string
+	}{
+		{"first read", func() { session.SetIDToken(first) }, first},
+		{"repeat read", func() {}, first},
+		{"after overwrite", func() { session.SetIDToken(second) }, second},
+		{"after clearing", func() { session.SetIDToken("") }, ""},
+		{"after Reset", func() { session.SetIDToken(first); _ = session.GetIDToken(); session.Reset() }, ""},
+	}
+	for _, st := range steps {
+		st.write()
+		if got := session.GetIDToken(); got != st.want {
+			t.Fatalf("%s: GetIDToken = %q, want %q", st.name, got, st.want)
+		}
+		if st.name == "repeat read" && session.idTokenMemoRaw != first {
+			t.Fatal("repeat read did not go through the memo; the test no longer covers it")
+		}
+	}
+	if session.idTokenMemoRaw != "" || session.idTokenMemo != "" {
+		t.Fatal("Reset left an ID-token memo on the pooled session")
+	}
+}

internal/cache/backends/redis.go

@@ -120,15 +120,8 @@ func (r *RedisBackend) Set(ctx context.Context, key string, value []byte, ttl ti
 
 		// Use PSETEX for millisecond precision, SETEX for second precision
 		if ttl > 0 {
-			ttlMillis := ttl.Milliseconds()
-			if ttlMillis < 1000 {
-				// Use PSETEX for sub-second TTLs (millisecond precision)
-				_, err = conn.Do("PSETEX", prefixedKey, fmt.Sprintf("%d", ttlMillis), string(value))
-			} else {
-				// Use SETEX for larger TTLs (second precision)
-				ttlSeconds := int(ttl.Seconds())
-				_, err = conn.Do("SETEX", prefixedKey, fmt.Sprintf("%d", ttlSeconds), string(value))
-			}
+			cmd, arg := ttlCommand(ttl)
+			_, err = conn.Do(cmd, prefixedKey, arg, string(value))
 		} else {
 			_, err = conn.Do("SET", prefixedKey, string(value))
 		}
@@ -624,6 +617,19 @@ func isRetryableError(err error) bool {
 	return false
 }
 
+// ttlCommand picks SETEX for whole seconds and PSETEX otherwise. The expiry is
+// rounded up to a millisecond and is never zero, so a key never dies early.
+func ttlCommand(ttl time.Duration) (cmd, arg string) {
+	ms := (ttl + time.Millisecond - 1).Milliseconds()
+	if ms < 1 {
+		ms = 1
+	}
+	if ms >= 1000 && ms%1000 == 0 {
+		return "SETEX", fmt.Sprintf("%d", ms/1000)
+	}
+	return "PSETEX", fmt.Sprintf("%d", ms)
+}
+
 // SetMany stores multiple values in Redis using pipelining for efficiency
 // This reduces N round-trips to a single round-trip
 func (r *RedisBackend) SetMany(ctx context.Context, items map[string][]byte, ttl time.Duration) error {
@@ -658,20 +664,16 @@ func (r *RedisBackend) SetMany(ctx context.Context, items map[string][]byte, ttl
 	pipeline := conn.NewPipeline()
 
 	// Queue all SET commands
-	ttlSeconds := int(ttl.Seconds())
-	ttlMillis := ttl.Milliseconds()
+	var ttlCmd, ttlArg string
+	if ttl > 0 {
+		ttlCmd, ttlArg = ttlCommand(ttl)
+	}
 
 	for key, value := range items {
 		prefixedKey := r.prefixKey(key)
 
 		if ttl > 0 {
-			if ttlMillis < 1000 {
-				// Use PSETEX for sub-second TTLs
-				pipeline.Queue("PSETEX", prefixedKey, fmt.Sprintf("%d", ttlMillis), string(value))
-			} else {
-				// Use SETEX for larger TTLs
-				pipeline.Queue("SETEX", prefixedKey, fmt.Sprintf("%d", ttlSeconds), string(value))
-			}
+			pipeline.Queue(ttlCmd, prefixedKey, ttlArg, string(value))
 		} else {
 			pipeline.Queue("SET", prefixedKey, string(value))
 		}

internal/cache/backends/redis_ttl_bounds_test.go

@@ -0,0 +1,45 @@
+package backends
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRedisSetTTLNeverZeroOrEarly(t *testing.T) {
+	mr := NewMiniredisServer(t)
+	b, err := NewRedisBackend(DefaultRedisConfig(mr.GetAddr()))
+	require.NoError(t, err)
+	defer b.Close()
+	ctx := context.Background()
+
+	t.Run("sub-millisecond ttl is accepted", func(t *testing.T) {
+		require.NoError(t, b.Set(ctx, "sub", []byte("v"), 500*time.Microsecond))
+	})
+	t.Run("sub-millisecond ttl accepted by SetMany", func(t *testing.T) {
+		require.NoError(t, b.SetMany(ctx, map[string][]byte{"sub-many": []byte("v")}, 500*time.Microsecond))
+	})
+	t.Run("fractional seconds are not rounded down", func(t *testing.T) {
+		require.NoError(t, b.Set(ctx, "frac", []byte("v"), 1999*time.Millisecond))
+		_, ttl, ok, err := b.Get(ctx, "frac")
+		require.NoError(t, err)
+		require.True(t, ok)
+		require.Greater(t, ttl, time.Second, "1999ms ttl must not be stored as 1s")
+	})
+	t.Run("fractional seconds SetMany", func(t *testing.T) {
+		require.NoError(t, b.SetMany(ctx, map[string][]byte{"frac-many": []byte("v")}, 1999*time.Millisecond))
+		_, ttl, ok, err := b.Get(ctx, "frac-many")
+		require.NoError(t, err)
+		require.True(t, ok)
+		require.Greater(t, ttl, time.Second)
+	})
+	t.Run("whole seconds still work", func(t *testing.T) {
+		require.NoError(t, b.Set(ctx, "whole", []byte("v"), 5*time.Second))
+		_, ttl, ok, err := b.Get(ctx, "whole")
+		require.NoError(t, err)
+		require.True(t, ok)
+		require.Greater(t, ttl, 3*time.Second)
+	})
+}

internal/cache/resilience/circuit_breaker.go

@@ -81,6 +81,7 @@ type CircuitBreaker struct {
 	stateMu             sync.RWMutex
 	timeMu              sync.RWMutex
 	halfOpenRequests    atomic.Int32
+	halfOpenSuccesses   atomic.Int32
 	consecutiveFailures atomic.Int32
 	state               atomic.Int32
 }
@@ -170,12 +171,12 @@ func (cb *CircuitBreaker) RecordSuccess() {
 
 	case StateHalfOpen:
 		// If we've had enough successful requests, close the circuit
-		successfulRequests := cb.halfOpenRequests.Load()
-		// #nosec G115 -- HalfOpenMaxRequests is a small config value that fits in int32
-		if successfulRequests >= int32(cb.config.HalfOpenMaxRequests) {
+		successfulRequests := cb.halfOpenSuccesses.Add(1)
+		if int64(successfulRequests) >= int64(cb.config.HalfOpenMaxRequests) {
 			cb.setState(StateClosed)
 			cb.consecutiveFailures.Store(0)
 			cb.halfOpenRequests.Store(0)
+			cb.halfOpenSuccesses.Store(0)
 		}
 	}
 }
@@ -216,6 +217,7 @@ func (cb *CircuitBreaker) RecordFailure() {
 func (cb *CircuitBreaker) openCircuit() {
 	cb.setState(StateOpen)
 	cb.halfOpenRequests.Store(0)
+	cb.halfOpenSuccesses.Store(0)
 
 	cb.timeMu.Lock()
 	cb.nextRetryTime = time.Now().Add(cb.config.Timeout)
@@ -251,6 +253,7 @@ func (cb *CircuitBreaker) Reset() {
 	cb.totalRequests.Store(0)
 	cb.totalFailures.Store(0)
 	cb.halfOpenRequests.Store(0)
+	cb.halfOpenSuccesses.Store(0)
 	cb.rejectedRequests.Store(0)
 	cb.stateTransitions.Store(0)
 

internal/cache/resilience/health_check_backend.go

@@ -168,11 +168,12 @@ func (h *HealthCheckBackend) IsHealthy() bool {
 func (h *HealthCheckBackend) recordResult(success bool) {
 	// #nosec G115 -- threshold config values are small integers that fit in int32
 	if success {
-		fails := h.consecutiveFails.Swap(0)
+		h.consecutiveFails.Store(0)
 		oks := h.consecutiveOK.Add(1)
 
-		// Check if we should transition to healthy
-		if fails > 0 && oks >= int32(h.config.HealthyThreshold) {
+		// Promote on a success streak. Keyed on the status, not on the fail
+		// counter, which the first success of the streak already zeroed.
+		if HealthStatus(h.status.Load()) != HealthHealthy && oks >= int32(h.config.HealthyThreshold) {
 			oldStatus := HealthStatus(h.status.Swap(int32(HealthHealthy)))
 			if oldStatus != HealthHealthy && h.config.OnStatusChange != nil {
 				h.config.OnStatusChange(oldStatus, HealthHealthy)

internal/cache/resilience/recovery_bounds_test.go

@@ -0,0 +1,56 @@
+package resilience
+
+import (
+	"testing"
+	"time"
+)
+
+// With HealthyThreshold >= 2 an Unhealthy backend must recover once it
+// answers HealthyThreshold times in a row.
+func TestHealthCheckRecoversWithThresholdTwo(t *testing.T) {
+	h := &HealthCheckBackend{config: &HealthCheckConfig{HealthyThreshold: 2, UnhealthyThreshold: 3}}
+	for i := 0; i < 6; i++ {
+		h.recordResult(false)
+	}
+	if HealthStatus(h.status.Load()) != HealthUnhealthy {
+		t.Fatalf("precondition: status=%v, want unhealthy", HealthStatus(h.status.Load()))
+	}
+	for i := 0; i < 5; i++ {
+		h.recordResult(true)
+	}
+	if got := HealthStatus(h.status.Load()); got != HealthHealthy {
+		t.Fatalf("status after 5 successes = %v, want healthy", got)
+	}
+}
+
+// Half-open closes after HalfOpenMaxRequests successes, not admissions.
+func TestHalfOpenClosesOnSuccessesNotAdmissions(t *testing.T) {
+	cb := NewCircuitBreaker(&CircuitBreakerConfig{
+		MaxFailures: 1, Timeout: time.Millisecond, HalfOpenMaxRequests: 3, ResetTimeout: time.Second,
+	})
+	cb.RecordFailure()
+	time.Sleep(20 * time.Millisecond)
+	for i := 0; i < 3; i++ {
+		if !cb.AllowRequest() {
+			t.Fatalf("probe %d rejected", i)
+		}
+	}
+	cb.RecordSuccess()
+	if cb.GetState() != StateHalfOpen {
+		t.Fatalf("closed after 1 of 3 probe successes; state=%v", cb.GetState())
+	}
+	cb.RecordFailure()
+	if cb.GetState() != StateOpen {
+		t.Fatalf("a failing probe must reopen; state=%v", cb.GetState())
+	}
+	time.Sleep(20 * time.Millisecond)
+	for i := 0; i < 3; i++ {
+		cb.AllowRequest()
+	}
+	for i := 0; i < 3; i++ {
+		cb.RecordSuccess()
+	}
+	if cb.GetState() != StateClosed {
+		t.Fatalf("state after 3 successes = %v, want closed", cb.GetState())
+	}
+}

internal/recovery/circuit_breaker.go

@@ -93,8 +93,16 @@ func (cb *CircuitBreaker) ExecuteWithContext(ctx context.Context, fn func() erro
 		return fmt.Errorf("circuit breaker is open")
 	}
 
-	// Execute the function
+	// A panicking fn must still settle the breaker, otherwise a half-open
+	// probe slot leaks until the next open->half-open transition.
+	panicked := true
+	defer func() {
+		if panicked {
+			cb.recordFailure()
+		}
+	}()
 	err := fn()
+	panicked = false
 
 	if err != nil {
 		cb.recordFailure()

internal/recovery/hunt_20261015_regression_test.go

@@ -0,0 +1,40 @@
+package recovery
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestCircuitBreaker_PanickingProbeReleasesHalfOpenSlot(t *testing.T) {
+	cb := NewCircuitBreaker(CircuitBreakerConfig{
+		FailureThreshold: 1,
+		SuccessThreshold: 1,
+		Timeout:          20 * time.Millisecond,
+		MaxRequests:      1,
+	}, &mockLogger{})
+
+	_ = cb.ExecuteWithContext(context.Background(), func() error { return errors.New("fail") })
+	time.Sleep(40 * time.Millisecond)
+
+	func() {
+		defer func() {
+			if recover() == nil {
+				t.Error("panic must still propagate to the caller")
+			}
+		}()
+		_ = cb.ExecuteWithContext(context.Background(), func() error { panic("boom") })
+	}()
+
+	if cb.GetState() != CircuitBreakerOpen {
+		t.Fatalf("state after panicking probe = %s, want open", cb.GetState())
+	}
+	time.Sleep(40 * time.Millisecond)
+	if err := cb.ExecuteWithContext(context.Background(), func() error { return nil }); err != nil {
+		t.Fatalf("probe after next timeout rejected: %v", err)
+	}
+	if cb.GetState() != CircuitBreakerClosed {
+		t.Fatalf("state = %s, want closed", cb.GetState())
+	}
+}

internal/utils/utils.go

@@ -142,7 +142,7 @@ func DetermineScheme(req *http.Request, forceHTTPS bool) string {
 	// "X-Forwarded-Proto: ftp") would otherwise be emitted verbatim into
 	// redirect_uri as a broken or weakened scheme. Invalid values fall
 	// through to the TLS check (R103).
-	if scheme := req.Header.Get("X-Forwarded-Proto"); scheme == "https" || scheme == "http" {
+	if scheme := strings.ToLower(req.Header.Get("X-Forwarded-Proto")); scheme == "https" || scheme == "http" {
 		return scheme
 	}
 

jwk.go

@@ -389,6 +389,13 @@ func (c *JWKCache) getPublicKeyFresh(ctx context.Context, jwksURL, kid string, h
 
 	if withinCooldown {
 		// Serve the cached keyset; do not fetch upstream again.
+		if v, found := c.cache.GetLocal(jwksURL + parsedKeysSuffix); found {
+			if pj, ok := v.(*parsedJWKS); ok {
+				if k, ok := pj.keys[kid]; ok {
+					return k, nil
+				}
+			}
+		}
 		if cached, found := c.cache.GetLocal(jwksURL); found {
 			if jwks, ok := cached.(*JWKSet); ok {
 				if k, ok := buildParsedJWKS(jwks).keys[kid]; ok {

jwt.go

@@ -6,7 +6,9 @@ import (
 	"crypto/ecdsa"
 	"crypto/rsa"
 	"encoding/base64"
+	"errors"
 	"fmt"
+	"math"
 	"math/big"
 	"strings"
 	"time"
@@ -194,11 +196,16 @@ func (j *JWT) Verify(issuerURL, expectedAudience string) error {
 //
 // Returns:
 //   - An error if the claim type is invalid or the expected audience is not present
+//
+// errInvalidAudience marks a token whose aud does not match; callers match it
+// with errors.Is, never by message text.
+var errInvalidAudience = errors.New("invalid audience")
+
 func verifyAudience(tokenAudience interface{}, expectedAudience string) error {
 	switch aud := tokenAudience.(type) {
 	case string:
 		if aud != expectedAudience {
-			return fmt.Errorf("invalid audience")
+			return errInvalidAudience
 		}
 	case []interface{}:
 		found := false
@@ -209,7 +216,7 @@ func verifyAudience(tokenAudience interface{}, expectedAudience string) error {
 			}
 		}
 		if !found {
-			return fmt.Errorf("invalid audience")
+			return errInvalidAudience
 		}
 	default:
 		return fmt.Errorf("invalid 'aud' claim type")
@@ -231,6 +238,9 @@ func verifyIssuer(tokenIssuer, expectedIssuer string) error {
 	return nil
 }
 
+// maxClaimUnix is 9999-12-31T23:59:59Z, the largest time claim accepted.
+const maxClaimUnix = 253402300799
+
 // verifyTimeConstraint validates time-based JWT claims with clock skew tolerance.
 // It handles both future constraints (exp) and past constraints (iat, nbf).
 // Parameters:
@@ -241,6 +251,10 @@ func verifyIssuer(tokenIssuer, expectedIssuer string) error {
 // Returns:
 //   - An error describing the failure (e.g., "token has expired", "token used before issued")
 func verifyTimeConstraint(unixTime float64, claimName string, future bool) error {
+	// int64(float64) wraps out of range, which put a far-future nbf/iat in the past.
+	if math.IsNaN(unixTime) || math.IsInf(unixTime, 0) || math.Abs(unixTime) > maxClaimUnix {
+		return fmt.Errorf("token %s claim out of range", claimName)
+	}
 	claimTime := time.Unix(int64(unixTime), 0)
 	now := time.Now()
 
@@ -314,6 +328,9 @@ func verifyTimeClaims(claims map[string]interface{}) error {
 	return nil
 }
 
+// ecdsaAlgBits maps an ES* algorithm to its curve size (RFC 7518 3.4).
+var ecdsaAlgBits = map[string]int{"ES256": 256, "ES384": 384, "ES512": 521}
+
 // verifySignatureWithKey verifies a JWT signature using an already-parsed
 // public key, skipping the PEM-encode/decode round trip. This is the hot
 // path used by VerifyJWTSignatureAndClaims and verifyLogoutTokenSignature.
@@ -361,7 +378,13 @@ func verifySignatureWithKey(tokenString string, pubKey crypto.PublicKey, alg str
 		if strings.HasPrefix(alg, "ES") {
 			var r, s big.Int
 			sigLen := len(signature)
-			if sigLen%2 != 0 {
+			// RFC 7518 3.4: the curve is fixed by the algorithm and the
+			// signature is R||S at exactly the curve's octet length.
+			bits := ecdsaAlgBits[alg]
+			if bits == 0 || pubKey.Curve.Params().BitSize != bits {
+				return fmt.Errorf("ECDSA key curve does not match algorithm %s", alg)
+			}
+			if sigLen != 2*((bits+7)/8) {
 				return fmt.Errorf("invalid ECDSA signature length")
 			}
 			r.SetBytes(signature[:sigLen/2])

jwt_ecdsa_strict_test.go

@@ -0,0 +1,53 @@
+package traefikoidc
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/base64"
+	"testing"
+)
+
+func signES(t *testing.T, key *ecdsa.PrivateKey, signed string, h256 bool, size int) (sigRS []byte) {
+	t.Helper()
+	var digest []byte
+	if h256 {
+		d := sha256.Sum256([]byte(signed))
+		digest = d[:]
+	} else {
+		d := sha512.Sum384([]byte(signed))
+		digest = d[:]
+	}
+	r, s, err := ecdsa.Sign(rand.Reader, key, digest)
+	if err != nil {
+		t.Fatal(err)
+	}
+	out := make([]byte, 2*size)
+	r.FillBytes(out[:size])
+	s.FillBytes(out[size:])
+	return out
+}
+
+func TestECDSAVerifyIsStrict(t *testing.T) {
+	const signed = "eyJhbGciOiJFUzI1NiJ9.eyJzdWIiOiJ1In0"
+	enc := base64.RawURLEncoding.EncodeToString
+	p256, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	p384, _ := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
+
+	if err := verifySignatureWithKey(signed+"."+enc(signES(t, p256, signed, true, 32)), &p256.PublicKey, "ES256"); err != nil {
+		t.Fatalf("valid ES256 rejected: %v", err)
+	}
+	if err := verifySignatureWithKey(signed+"."+enc(signES(t, p384, signed, false, 48)), &p384.PublicKey, "ES384"); err != nil {
+		t.Fatalf("valid ES384 rejected: %v", err)
+	}
+	// ES256 token verified against a P-384 key.
+	if err := verifySignatureWithKey(signed+"."+enc(signES(t, p384, signed, true, 48)), &p384.PublicKey, "ES256"); err == nil {
+		t.Error("ES256 accepted with a P-384 key")
+	}
+	// Zero-padded halves: 66 bytes for ES256.
+	if err := verifySignatureWithKey(signed+"."+enc(signES(t, p256, signed, true, 33)), &p256.PublicKey, "ES256"); err == nil {
+		t.Error("ES256 accepted a 66-byte signature")
+	}
+}

logout.go

@@ -51,8 +51,43 @@ const (
 	// sessionInvalidationTTL is how long to remember invalidated sessions
 	// Should be at least as long as your session max age
 	sessionInvalidationTTL = 25 * time.Hour
+
+	// maxFrontchannelMarkers caps the sid markers the unauthenticated
+	// front-channel endpoint may keep in the shared invalidation cache, so
+	// a flood cannot LRU-evict signed backchannel and jti replay markers.
+	maxFrontchannelMarkers = 1000
 )
 
+// markerQuota is a FIFO of cache keys written on behalf of one untrusted
+// source. The zero value is ready to use.
+type markerQuota struct {
+	set  map[string]struct{}
+	keys []string
+	mu   sync.Mutex
+}
+
+// admit records key and returns the oldest key to drop once more than limit
+// keys are held, or "" when none must go. Re-admitting a held key is a no-op.
+func (q *markerQuota) admit(key string, limit int) string {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	if q.set == nil {
+		q.set = make(map[string]struct{})
+	}
+	if _, ok := q.set[key]; ok {
+		return ""
+	}
+	q.set[key] = struct{}{}
+	q.keys = append(q.keys, key)
+	if len(q.keys) <= limit {
+		return ""
+	}
+	oldest := q.keys[0]
+	q.keys = q.keys[1:]
+	delete(q.set, oldest)
+	return oldest
+}
+
 // LogoutTokenClaims represents the claims in an OIDC logout token
 // as defined in OpenID Connect Back-Channel Logout 1.0
 type LogoutTokenClaims struct {
@@ -191,6 +226,10 @@ func (t *TraefikOidc) handleFrontchannelLogout(rw http.ResponseWriter, req *http
 		return
 	}
 
+	if evicted := t.frontchannelMarkers.admit(t.buildSessionInvalidationKey("sid", sid), maxFrontchannelMarkers); evicted != "" {
+		t.sessionInvalidationCache.Delete(evicted)
+	}
+
 	t.logger.Infof("Front-channel logout: successfully invalidated session (sid=%s)", sid)
 
 	// Return a minimal HTML response that's suitable for iframe loading
@@ -578,6 +617,11 @@ func (t *TraefikOidc) isSessionInvalidated(sid, sub string, sessionCreatedAt tim
 
 // buildSessionInvalidationKey creates a cache key for session invalidation
 func (t *TraefikOidc) buildSessionInvalidationKey(keyType, value string) string {
+	// sub, sid and jti are unique only within an issuer; the cache is shared by
+	// every instance, so scope the key to this instance's provider and client.
+	if ns := t.tokenCache.Namespace(); ns != "" {
+		return fmt.Sprintf("session_invalidation:%s|%s:%s", ns, keyType, value)
+	}
 	return fmt.Sprintf("session_invalidation:%s:%s", keyType, value)
 }
 
@@ -600,6 +644,22 @@ func (t *TraefikOidc) sessionCreatedAtForInvalidation(idToken string, session *S
 	return time.Time{} // zero: treated as invalidated -> safe re-auth
 }
 
+// invalidationInputs returns sid, sub and the creation time for the IdP-logout
+// check from one parseJWT call, with the same results as extractSessionInfo
+// and sessionCreatedAtForInvalidation called separately.
+func (t *TraefikOidc) invalidationInputs(idToken string, session *SessionData) (sid, sub string, createdAt time.Time) {
+	jwt, err := parseJWT(idToken)
+	if err != nil {
+		return "", "", t.sessionCreatedAtForInvalidation("", session)
+	}
+	sid, _ = jwt.Claims["sid"].(string)
+	sub, _ = jwt.Claims["sub"].(string)
+	if iat, ok := jwt.Claims["iat"].(float64); ok {
+		return sid, sub, time.Unix(int64(iat), 0)
+	}
+	return sid, sub, t.sessionCreatedAtForInvalidation("", session)
+}
+
 // extractSessionInfo extracts sid and sub from an ID token for session tracking
 func (t *TraefikOidc) extractSessionInfo(idToken string) (sid, sub string, createdAt time.Time) {
 	if idToken == "" {

logout_invalidation_inputs_test.go

@@ -0,0 +1,34 @@
+package traefikoidc
+
+import (
+	"testing"
+
+	"github.com/gorilla/sessions"
+)
+
+// invalidationInputs must return exactly what extractSessionInfo and
+// sessionCreatedAtForInvalidation return when called separately.
+func TestInvalidationInputsMatchSeparateCalls(t *testing.T) {
+	oidc := &TraefikOidc{logger: newNoOpLogger()}
+	sess := &SessionData{mainSession: &sessions.Session{Values: map[interface{}]interface{}{"created_at": int64(1700000000)}}}
+
+	tokens := map[string]string{
+		"all claims":  makeTestJWT(t, map[string]interface{}{"sid": "s1", "sub": "u1", "iat": float64(1700000100)}),
+		"no iat":      makeTestJWT(t, map[string]interface{}{"sid": "s1", "sub": "u1"}),
+		"sid only":    makeTestJWT(t, map[string]interface{}{"sid": "s1", "iat": float64(1700000200)}),
+		"sub only":    makeTestJWT(t, map[string]interface{}{"sub": "u1"}),
+		"wrong types": makeTestJWT(t, map[string]interface{}{"sid": 5, "sub": true, "iat": "x"}),
+		"malformed":   "not-a-jwt",
+		"empty":       "",
+	}
+	for name, tok := range tokens {
+		t.Run(name, func(t *testing.T) {
+			wantSID, wantSub, _ := oidc.extractSessionInfo(tok)
+			wantAt := oidc.sessionCreatedAtForInvalidation(tok, sess)
+			gotSID, gotSub, gotAt := oidc.invalidationInputs(tok, sess)
+			if gotSID != wantSID || gotSub != wantSub || !gotAt.Equal(wantAt) {
+				t.Fatalf("got (%q,%q,%v) want (%q,%q,%v)", gotSID, gotSub, gotAt, wantSID, wantSub, wantAt)
+			}
+		})
+	}
+}

logout_key_scope_test.go

@@ -0,0 +1,18 @@
+package traefikoidc
+
+import "testing"
+
+func TestSessionInvalidationKeyScopedPerInstance(t *testing.T) {
+	a := &TraefikOidc{tokenCache: &TokenCache{}}
+	b := &TraefikOidc{tokenCache: &TokenCache{}}
+	a.tokenCache.SetNamespace("https://kc/realms/a|c|c")
+	b.tokenCache.SetNamespace("https://kc/realms/b|c|c")
+	for _, kind := range []string{"sub", "sid", "jti"} {
+		if a.buildSessionInvalidationKey(kind, "u1") == b.buildSessionInvalidationKey(kind, "u1") {
+			t.Errorf("%s key shared across issuers", kind)
+		}
+	}
+	if got := (&TraefikOidc{}).buildSessionInvalidationKey("sub", "u1"); got != "session_invalidation:sub:u1" {
+		t.Errorf("namespace-less key changed: %q", got)
+	}
+}

main.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"net/http"
@@ -85,8 +86,10 @@ var defaultExcludedURLs = map[string]struct{}{
 
 // headerTemplateFuncMap returns the function map available to custom header
 // value templates, gated by the effective claims whitelist (built-in +
-// config.AllowedClaims). It exposes exactly two helpers:
+// config.AllowedClaims). It exposes exactly three helpers:
 //   - default: substitute a fallback when a value is nil/empty.
+//   - toJson: serialize a value (e.g. an object claim) to compact JSON; nil and
+//     "" yield "" so an absent claim skips the header instead of sending `""`.
 //   - get: safe map access RESTRICTED to whitelisted claim keys, so it cannot be
 //     used to read a non-whitelisted claim, a raw token, or the whole data map
 //     (issue #149 review). This is the sole runtime enforcement of the claims
@@ -102,6 +105,16 @@ func headerTemplateFuncMap(allowedClaims map[string]bool) template.FuncMap {
 			}
 			return val
 		},
+		"toJson": func(val interface{}) (string, error) {
+			if val == nil || val == "" {
+				return "", nil
+			}
+			b, err := json.Marshal(val)
+			if err != nil {
+				return "", err
+			}
+			return string(b), nil
+		},
 		"get": func(m interface{}, key string) interface{} {
 			if !allowedClaims[key] {
 				return ""
@@ -535,6 +548,7 @@ func NewWithContext(ctx context.Context, config *Config, next http.Handler, name
 	logger.Debugf("TraefikOidc.New: logoutURLPath configured as: %q", t.logoutURLPath)
 
 	t.providerURL = config.ProviderURL
+	t.tokenCache.SetNamespace(t.tokenCacheNamespace())
 
 	// Use singleton resource manager for metadata initialization
 	rm := GetResourceManager()
@@ -931,6 +945,7 @@ func (t *TraefikOidc) performDynamicClientRegistration() {
 	if t.audience == "" {
 		t.audience = resp.ClientID // Default audience to client ID
 	}
+	t.tokenCache.SetNamespace(t.tokenCacheNamespace())
 	// R162: DCR can provision a client whose method is private_key_jwt
 	// (RFC 7591 ClientMetadata.TokenEndpointAuthMethod) even when the
 	// static config did not set ClientAuthMethod=private_key_jwt. In that
@@ -1070,3 +1085,8 @@ func buildFullURL(scheme, host, path string) string {
 
 	return fmt.Sprintf("%s://%s%s", scheme, host, path)
 }
+
+// tokenCacheNamespace identifies the verification context of this instance.
+func (t *TraefikOidc) tokenCacheNamespace() string {
+	return t.providerURL + "|" + t.clientID + "|" + t.audience
+}

middleware.go

@@ -158,6 +158,15 @@ func (w *optionsPreflightWriter) Write(b []byte) (int, error) {
 	return len(b), nil
 }
 
+const (
+	// maxInitWaiters bounds requests parked on initComplete so a boot-time
+	// flood with the IdP down cannot hold unbounded connections for 30s each.
+	maxInitWaiters = 512
+	// initWaitRetryAfter is the Retry-After value (seconds) sent when the
+	// init-wait queue is full.
+	initWaitRetryAfter = "5"
+)
+
 // bypassReason describes why a request is being forwarded without OIDC auth.
 // It is only used for logging and to decide whether extra side-effects
 // (propagating the user header from an existing session) should run.
@@ -701,6 +710,13 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	// Log waiting for initialization to help diagnose hanging requests
 	t.logger.Debug("Waiting for OIDC provider initialization...")
 
+	if atomic.AddInt32(&t.initWaiters, 1) > maxInitWaiters {
+		atomic.AddInt32(&t.initWaiters, -1)
+		rw.Header().Set("Retry-After", initWaitRetryAfter)
+		t.sendErrorResponse(rw, req, "OIDC provider initialization in progress - please try again later", http.StatusServiceUnavailable)
+		return
+	}
+
 	// time.NewTimer + Stop avoids leaking a goroutine+channel for 30s on every
 	// request when initComplete fires quickly (would happen with time.After).
 	initTimer := time.NewTimer(30 * time.Second)
@@ -708,6 +724,7 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 
 	select {
 	case <-t.initComplete:
+		atomic.AddInt32(&t.initWaiters, -1)
 		// Read issuerURL via atomic snapshot when available — replaces the
 		// metadataMu.RLock that previously fired on every non-bypass request.
 		// Under Yaegi each RLock acquisition costs 1-5ms of interpreter
@@ -744,10 +761,12 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 			return
 		}
 	case <-req.Context().Done():
+		atomic.AddInt32(&t.initWaiters, -1)
 		t.logger.Debug("Request canceled while waiting for OIDC initialization")
 		t.sendErrorResponse(rw, req, "Request canceled", http.StatusRequestTimeout)
 		return
 	case <-initTimer.C:
+		atomic.AddInt32(&t.initWaiters, -1)
 		t.logger.Error("Timeout waiting for OIDC initialization")
 		t.sendErrorResponse(rw, req, "Timeout waiting for OIDC provider initialization - please try again later", http.StatusServiceUnavailable)
 		return
@@ -1035,8 +1054,7 @@ func (t *TraefikOidc) processAuthorizedRequestRS(rw http.ResponseWriter, req *ht
 	idToken := rs.idToken
 	if t.enableBackchannelLogout || t.enableFrontchannelLogout {
 		if idToken != "" {
-			sid, sub, _ := t.extractSessionInfo(idToken)
-			createdAt := t.sessionCreatedAtForInvalidation(idToken, session)
+			sid, sub, createdAt := t.invalidationInputs(idToken, session)
 			if t.isSessionInvalidated(sid, sub, createdAt) {
 				t.logger.Infof("Session for user %s has been invalidated via IdP-initiated logout", userIdentifier)
 				if err := session.Clear(req, rw); err != nil {
@@ -1128,8 +1146,7 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
 	if t.enableBackchannelLogout || t.enableFrontchannelLogout {
 		idToken := session.GetIDToken()
 		if idToken != "" {
-			sid, sub, _ := t.extractSessionInfo(idToken)
-			createdAt := t.sessionCreatedAtForInvalidation(idToken, session)
+			sid, sub, createdAt := t.invalidationInputs(idToken, session)
 			if t.isSessionInvalidated(sid, sub, createdAt) {
 				t.logger.Infof("Session for user %s has been invalidated via IdP-initiated logout", userIdentifier)
 				// Clear the session and redirect to login
@@ -1324,6 +1341,23 @@ func joinBoundedClaimHeader(values []string) string {
 	return b.String()
 }
 
+// dropInboundTemplated removes a client-supplied value for a header the
+// middleware owns, so a skipped render leaves it absent instead of forwarding
+// the client's. Identity headers (already stripped and re-injected) and
+// Authorization (the inbound bearer credential) are left alone.
+func dropInboundTemplated(req *http.Request, name string) {
+	canon := http.CanonicalHeaderKey(name)
+	if canon == "Authorization" {
+		return
+	}
+	for _, h := range identityHeaders {
+		if canon == http.CanonicalHeaderKey(h) {
+			return
+		}
+	}
+	req.Header.Del(canon)
+}
+
 // applyHeaderTemplates renders the configured header templates for p onto req.
 func (t *TraefikOidc) applyHeaderTemplates(req *http.Request, p *principal) {
 	if len(t.headerTemplates) == 0 {
@@ -1342,6 +1376,7 @@ func (t *TraefikOidc) applyHeaderTemplates(req *http.Request, p *principal) {
 	}
 
 	for headerName, tmpl := range t.headerTemplates {
+		dropInboundTemplated(req, headerName)
 		var buf bytes.Buffer
 		if err := tmpl.Execute(&buf, templateData); err != nil {
 			t.logger.Errorf("Failed to execute template for header %s: %v", headerName, err)
@@ -1371,7 +1406,11 @@ func (t *TraefikOidc) applyHeaderTemplates(req *http.Request, p *principal) {
 		// forwarding a tainted value. Do not log the value (it commonly
 		// carries the access token); log only name + reason.
 		if reason := headerValueReason(headerValue, headerTemplateMaxLen); reason != "" {
-			t.logger.Debugf("Dropping templated header %s: value failed sanitization (%s)", headerName, reason)
+			if reason == headerReasonTooLong {
+				t.logger.Errorf("Dropping templated header %s: rendered value exceeds %d bytes", headerName, headerTemplateMaxLen)
+			} else {
+				t.logger.Debugf("Dropping templated header %s: value failed sanitization (%s)", headerName, reason)
+			}
 			continue
 		}
 		req.Header.Set(headerName, headerValue)

per_source_ratelimit.go

@@ -62,10 +62,11 @@ func (l *perSourceAuthLimiter) allow(req *http.Request) bool {
 	if now.Sub(l.lastSweep) >= time.Minute {
 		l.sweep(now)
 	}
-	e := l.entries[ip]
+	key := limiterKey(ip)
+	e := l.entries[key]
 	if e == nil {
 		e = &perSourceAuthEntry{limiter: rate.NewLimiter(l.limit, l.burst)}
-		l.entries[ip] = e
+		l.entries[key] = e
 	}
 	e.lastSeen = now
 	return e.limiter.Allow()
@@ -115,3 +116,19 @@ func isInternalSource(ip string) bool {
 	return p.IsLoopback() || p.IsPrivate() || p.IsLinkLocalUnicast() ||
 		p.IsLinkLocalMulticast() || p.IsUnspecified()
 }
+
+// ipv6PrefixBits is the IPv6 prefix that shares one bucket: a host holds a
+// whole /64, so per-address keys would give it 2^64 buckets.
+const ipv6PrefixBits = 64
+
+// limiterKey maps a source IP to its bucket key (IPv6 collapses to its /64).
+func limiterKey(ip string) string {
+	p := net.ParseIP(ip)
+	if p == nil {
+		return ip
+	}
+	if p.To4() != nil {
+		return p.String()
+	}
+	return (&net.IPNet{IP: p.Mask(net.CIDRMask(ipv6PrefixBits, 128)), Mask: net.CIDRMask(ipv6PrefixBits, 128)}).String()
+}

per_source_ratelimit_ipv6_test.go

@@ -0,0 +1,49 @@
+package traefikoidc
+
+import (
+	"fmt"
+	"net/http/httptest"
+	"testing"
+)
+
+// An IPv6 /64 holder must share one bucket; per-address keys let one host
+// mint 2^64 buckets and bypass the throttle.
+func TestPerSourceLimiter_IPv6SamePrefixSharesBucket(t *testing.T) {
+	const burst = 3
+	l := newPerSourceAuthLimiter(burst)
+	allowed := 0
+	for i := 0; i < 50; i++ {
+		req := httptest.NewRequest("GET", "/", nil)
+		req.RemoteAddr = fmt.Sprintf("[2001:db8:1:2::%x]:1234", i+1)
+		if l.allow(req) {
+			allowed++
+		}
+	}
+	if allowed > burst {
+		t.Fatalf("one /64 got %d allows, want <= %d", allowed, burst)
+	}
+}
+
+func TestPerSourceLimiter_IPv6DifferentPrefixIndependent(t *testing.T) {
+	l := newPerSourceAuthLimiter(1)
+	a := httptest.NewRequest("GET", "/", nil)
+	a.RemoteAddr = "[2001:db8:1:2::1]:1"
+	b := httptest.NewRequest("GET", "/", nil)
+	b.RemoteAddr = "[2001:db8:1:3::1]:1"
+	if !l.allow(a) || !l.allow(b) {
+		t.Fatal("distinct /64 prefixes must have independent buckets")
+	}
+}
+
+func TestLimiterKey(t *testing.T) {
+	cases := map[string]string{
+		"192.0.2.1":        "192.0.2.1",
+		"2001:db8:1:2::9":  "2001:db8:1:2::/64",
+		"::ffff:192.0.2.1": "192.0.2.1",
+	}
+	for in, want := range cases {
+		if got := limiterKey(in); got != want {
+			t.Errorf("limiterKey(%q)=%q want %q", in, got, want)
+		}
+	}
+}

refresh_cleanup_chunktrim_test.go

@@ -0,0 +1,49 @@
+package traefikoidc
+
+import (
+	"testing"
+	"time"
+
+	"github.com/gorilla/sessions"
+)
+
+// Cleanup must not evict a tracker whose cooldown is still running.
+func TestRefreshCleanupKeepsTrackerInCooldown(t *testing.T) {
+	cfg := DefaultRefreshCoordinatorConfig()
+	cfg.MaxRefreshAttempts = 2
+	cfg.RefreshAttemptWindow = 20 * time.Millisecond
+	cfg.RefreshCooldownPeriod = time.Hour
+	rc := NewRefreshCoordinator(cfg, GetSingletonNoOpLogger())
+	defer rc.Shutdown()
+
+	rc.recordRefreshAttempt("s")
+	rc.recordRefreshAttempt("s")
+	if !rc.isInCooldown("s") {
+		t.Fatal("precondition: session must enter cooldown")
+	}
+	time.Sleep(80 * time.Millisecond)
+	rc.cleanupStaleEntries()
+	if !rc.isInCooldown("s") {
+		t.Fatal("cleanup evicted a tracker still in cooldown")
+	}
+}
+
+// Stale chunks above token_total must be dropped by key, even when the key
+// set is sparse.
+func TestChunkTrimDropsStaleSparseKeys(t *testing.T) {
+	cm := NewChunkManager(newNoOpLogger())
+	mk := func(s string, total interface{}) *sessions.Session {
+		v := map[interface{}]interface{}{"token_chunk": s}
+		if total != nil {
+			v["token_total"] = total
+		}
+		return &sessions.Session{Values: v}
+	}
+	chunks := map[int]*sessions.Session{
+		0: mk("Zq8xK2mP", 3), 1: mk("r7TnB4wY", nil), 2: mk("c9LdG5sH", nil), 7: mk("stale", nil),
+	}
+	res := cm.processChunkedToken(chunks, RefreshTokenConfig)
+	if res.Error != nil || res.Token != "Zq8xK2mPr7TnB4wYc9LdG5sH" {
+		t.Fatalf("token=%q err=%v, want Zq8xK2mPr7TnB4wYc9LdG5sH", res.Token, res.Error)
+	}
+}

refresh_coordinator.go

@@ -672,7 +672,6 @@ func (rc *RefreshCoordinator) isInCooldown(sessionID string) bool {
 			}
 			return &attemptState{
 				windowStartNano: nowNano,
-				attempts:        1,
 			}
 		})
 		return false
@@ -686,7 +685,7 @@ func (rc *RefreshCoordinator) isInCooldown(sessionID string) bool {
 			}
 			next := *s
 			next.windowStartNano = nowNano
-			next.attempts = 1
+			next.attempts = 0
 			return &next
 		})
 		return false
@@ -824,13 +823,16 @@ func (rc *RefreshCoordinator) cleanupRoutine() {
 // cleanupStaleEntries removes outdated tracking entries. Lock-free iteration
 // via sync.Map.Range; safe to race with concurrent reads/writes.
 func (rc *RefreshCoordinator) cleanupStaleEntries() {
-	cutoff := time.Now().Add(-2 * rc.config.RefreshAttemptWindow).UnixNano()
+	now := time.Now()
+	cutoff := now.Add(-2 * rc.config.RefreshAttemptWindow).UnixNano()
+	nowNano := now.UnixNano()
 	rc.sessionRefreshAttempts.Range(func(key, value interface{}) bool {
 		tracker := trackerFromMapValue(value)
 		if tracker == nil {
 			return true
 		}
-		if tracker.stateOf().lastAttemptNano < cutoff {
+		st := tracker.stateOf()
+		if st.lastAttemptNano < cutoff && st.cooldownEndNano <= nowNano {
 			// Compare-and-delete to avoid evicting a tracker that was just
 			// re-used by a concurrent caller. We compare by pointer identity.
 			rc.sessionRefreshAttempts.CompareAndDelete(key, value)
@@ -939,20 +941,28 @@ func (cb *RefreshCircuitBreaker) AllowRequest() bool {
 		return true
 	case 1: // open
 		lastFail := atomic.LoadInt64(&cb.lastFailureNano)
-		if time.Duration(time.Now().UnixNano()-lastFail) > cb.config.OpenDuration {
-			// Transition to half-open; first CAS winner gets the probe.
-			if atomic.CompareAndSwapInt32(&cb.state, 1, 2) {
-				return true
-			}
-		}
-		return false
-	case 2: // half-open
-		return true
+		return cb.claimProbe(lastFail)
+	case 2: // half-open: one probe at a time; a stale probe is replaced
+		return cb.claimProbe(atomic.LoadInt64(&cb.lastFailureNano))
 	default:
 		return false
 	}
 }
 
+// claimProbe admits one probe when OpenDuration has passed since lastFail.
+// The CAS on lastFailureNano makes the claim exclusive and restarts the clock.
+func (cb *RefreshCircuitBreaker) claimProbe(lastFail int64) bool {
+	now := time.Now().UnixNano()
+	if time.Duration(now-lastFail) <= cb.config.OpenDuration {
+		return false
+	}
+	if !atomic.CompareAndSwapInt64(&cb.lastFailureNano, lastFail, now) {
+		return false
+	}
+	atomic.StoreInt32(&cb.state, 2)
+	return true
+}
+
 // RecordSuccess records a successful operation. Lock-free.
 func (cb *RefreshCircuitBreaker) RecordSuccess() {
 	switch atomic.LoadInt32(&cb.state) {

refresh_window_halfopen_test.go

@@ -0,0 +1,93 @@
+package traefikoidc
+
+import (
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+// After a window reset the tracker must allow the full MaxRefreshAttempts,
+// the same as a fresh tracker.
+func TestRefreshWindowResetAllowsFullQuota(t *testing.T) {
+	cfg := DefaultRefreshCoordinatorConfig()
+	cfg.MaxRefreshAttempts = 3
+	cfg.RefreshAttemptWindow = 50 * time.Millisecond
+	cfg.RefreshCooldownPeriod = time.Hour
+	rc := NewRefreshCoordinator(cfg, GetSingletonNoOpLogger())
+	defer rc.Shutdown()
+
+	pass := func() int {
+		n := 0
+		for i := 0; i < 10; i++ {
+			if rc.isInCooldown("s") {
+				break
+			}
+			rc.recordRefreshAttempt("s")
+			n++
+		}
+		return n
+	}
+	if got := pass(); got != 3 {
+		t.Fatalf("fresh window passes=%d want 3", got)
+	}
+	// Window expiry alone cannot reset while in cooldown, so use a new
+	// session that never hits the cap: record 1, wait out the window.
+	rc.recordRefreshAttempt("w")
+	time.Sleep(80 * time.Millisecond)
+	n := 0
+	for i := 0; i < 10; i++ {
+		if rc.isInCooldown("w") {
+			break
+		}
+		rc.recordRefreshAttempt("w")
+		n++
+	}
+	if n != 3 {
+		t.Fatalf("post-reset window passes=%d want 3", n)
+	}
+}
+
+// Half-open admits a single probe until it reports.
+func TestRefreshBreakerHalfOpenSingleProbe(t *testing.T) {
+	cb := &RefreshCircuitBreaker{config: RefreshCircuitBreakerConfig{
+		MaxFailures: 1, OpenDuration: 20 * time.Millisecond, HalfOpenRequests: 1,
+	}}
+	cb.RecordFailure()
+	time.Sleep(40 * time.Millisecond)
+	var admitted int32
+	var wg sync.WaitGroup
+	for i := 0; i < 20; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if cb.AllowRequest() {
+				atomic.AddInt32(&admitted, 1)
+			}
+		}()
+	}
+	wg.Wait()
+	if admitted != 1 {
+		t.Fatalf("half-open admitted %d, want 1", admitted)
+	}
+	cb.RecordSuccess()
+	if !cb.AllowRequest() {
+		t.Fatal("breaker must close after probe success")
+	}
+}
+
+// A probe that never reports must not wedge the breaker.
+func TestRefreshBreakerHalfOpenProbeTimeout(t *testing.T) {
+	cb := &RefreshCircuitBreaker{config: RefreshCircuitBreakerConfig{
+		MaxFailures: 1, OpenDuration: 20 * time.Millisecond, HalfOpenRequests: 1,
+	}}
+	cb.RecordFailure()
+	time.Sleep(40 * time.Millisecond)
+	if !cb.AllowRequest() || cb.AllowRequest() {
+		t.Fatal("want exactly one probe")
+	}
+	time.Sleep(40 * time.Millisecond)
+	if !cb.AllowRequest() {
+		t.Fatal("stale probe must allow a new one")
+	}
+}

session.go

@@ -116,6 +116,10 @@ const (
 	defaultCookiePrefix  = "_oidc_raczylo_"
 )
 
+// maxCleanupCookies bounds the cookie names CleanupOldCookies emits deletion
+// headers for per response (up to 4 Set-Cookie headers each).
+const maxCleanupCookies = 32
+
 const (
 	// maxCookieSize is the maximum raw data size per chunk before securecookie encoding.
 	//
@@ -193,8 +197,10 @@ func compressCombinedPayload(payload *combinedSessionPayload) (string, error) {
 }
 
 // decompressCombinedPayload decompresses a base64+gzip encoded combined session payload.
+// readers pools *gzip.Reader values: a new reader allocates its 32 KB window,
+// which is a large per-request cost under yaegi.
 // Returns the deserialized payload and any error encountered.
-func decompressCombinedPayload(compressed string) (*combinedSessionPayload, error) {
+func decompressCombinedPayload(compressed string, readers *sync.Pool) (*combinedSessionPayload, error) {
 	if compressed == "" {
 		return nil, fmt.Errorf("empty compressed data")
 	}
@@ -204,11 +210,16 @@ func decompressCombinedPayload(compressed string) (*combinedSessionPayload, erro
 		return nil, fmt.Errorf("failed to decode base64: %w", err)
 	}
 
-	gr, err := gzip.NewReader(bytes.NewReader(data))
+	gr, _ := readers.Get().(*gzip.Reader)
+	if gr == nil {
+		gr, err = gzip.NewReader(bytes.NewReader(data))
+	} else {
+		err = gr.Reset(bytes.NewReader(data))
+	}
 	if err != nil {
 		return nil, fmt.Errorf("failed to create gzip reader: %w", err)
 	}
-	defer func() { _ = gr.Close() }()
+	defer readers.Put(gr)
 
 	// Limit decompressed size to prevent zip bombs
 	limitedReader := io.LimitReader(gr, 512*1024) // 512KB max
@@ -408,6 +419,7 @@ func decompressTokenInternal(compressed string) string {
 // session object reuse and supports both HTTP and HTTPS schemes.
 type SessionManager struct {
 	sessionPool    sync.Pool
+	gzipReaders    sync.Pool
 	ctx            context.Context
 	store          sessions.Store
 	logger         *Logger
@@ -929,6 +941,9 @@ func (sm *SessionManager) EnhanceSessionSecurity(options *sessions.Options, r *h
 			// service). Keep it unless it is a strict parent of the serving
 			// host, which would scope the token-bearing cookie to sibling
 			// subdomains — then fall back to the serving host.
+			// DNS names and the cookie Domain attribute are case-insensitive.
+			host = strings.ToLower(host)
+			fh = strings.ToLower(fh)
 			if !strings.HasSuffix(host, "."+fh) {
 				host = fh
 			}
@@ -1016,6 +1031,7 @@ func (sm *SessionManager) CleanupOldCookies(w http.ResponseWriter, r *http.Reque
 	}
 
 	processedCookies := make(map[string]bool)
+	deletedCookies := 0
 
 	for _, cookie := range cookies {
 		// Check if cookie belongs to this middleware instance using the configured prefix
@@ -1029,7 +1045,8 @@ func (sm *SessionManager) CleanupOldCookies(w http.ResponseWriter, r *http.Reque
 			shouldCleanup := currentDomain != "" && !sm.cleanupDone
 			sm.cleanupMutex.RUnlock()
 
-			if shouldCleanup {
+			if shouldCleanup && deletedCookies < maxCleanupCookies {
+				deletedCookies++
 				for _, domain := range domainsToClean {
 					if domain == currentDomain || domain == "."+currentDomain || "."+domain == currentDomain {
 						continue
@@ -1265,7 +1282,7 @@ func (sm *SessionManager) loadFromCombinedCookies(r *http.Request, sessionData *
 		return false
 	}
 
-	payload, err := decompressCombinedPayload(compressed)
+	payload, err := decompressCombinedPayload(compressed, &sm.gzipReaders)
 	if err != nil {
 		sm.logger.Debugf("Failed to decompress combined payload: %v", err)
 		return false
@@ -1410,6 +1427,13 @@ type SessionData struct {
 	// timed against the new owner's own writes.
 	sessionOwner atomic.Uint64
 
+	// idTokenMemoRaw and idTokenMemo cache getIDTokenUnsafe's validated result
+	// for an unchunked, uncompressed stored token, keyed by the stored value.
+	// A request reads the ID token twice, and each read re-ran full chunk
+	// validation. Cleared by Reset so no result outlives its request.
+	idTokenMemoRaw string
+	idTokenMemo    string
+
 	// cachedClaimsToken is the ID token string whose claims were last parsed and
 	// cached. A lazy, per-request cache to avoid re-parsing the JWT on every
 	// authenticated request (e.g. for headerTemplates). Protected by sessionMutex.
@@ -2086,6 +2110,8 @@ func (sd *SessionData) Reset() {
 	sd.cachedClaimsToken = ""
 	sd.cachedClaims = nil
 	sd.cachedClaimsErr = nil
+	sd.idTokenMemoRaw = ""
+	sd.idTokenMemo = ""
 
 	// Reset the refresh mutex to ensure clean state
 	// Note: We don't need to lock it since sessionMutex is already held
@@ -2276,6 +2302,13 @@ func (sd *SessionData) SetAccessToken(token string) {
 			return
 		}
 
+		// Chunk cookies bind to the request; without one the store cannot
+		// complete, so keep the previous token.
+		if sd.request == nil {
+			sd.manager.logger.Error("SetAccessToken: sd.request is nil, cannot create chunk sessions")
+			return
+		}
+
 		// Validation passed: now it is safe to clear the existing token
 		// before storing the new chunked one.
 		sd.clearAccessTokenChunks()
@@ -2911,6 +2944,9 @@ func (sd *SessionData) GetIncomingPath() string {
 	return path
 }
 
+// maxIncomingPathLen bounds the post-login redirect path kept in the session.
+const maxIncomingPathLen = 2048
+
 // SetIncomingPath stores the original request URI for post-authentication redirect.
 // This allows the user to be redirected to their originally requested resource
 // after completing the authentication flow.
@@ -2919,6 +2955,11 @@ func (sd *SessionData) GetIncomingPath() string {
 func (sd *SessionData) SetIncomingPath(path string) {
 	sd.sessionMutex.Lock()
 	defer sd.sessionMutex.Unlock()
+	// The path becomes cookie bytes on every later request; an oversized one
+	// would bloat the Cookie header or fail the save. Fall back to "/".
+	if len(path) > maxIncomingPathLen {
+		path = ""
+	}
 	currentVal, _ := sd.mainSession.Values["incoming_path"].(string)
 	if currentVal != path {
 		sd.mainSession.Values["incoming_path"] = path
@@ -3017,6 +3058,11 @@ func (sd *SessionData) getIDTokenUnsafe() string {
 		return token
 	}
 
+	memoable := token != "" && !compressed && len(sd.idTokenChunks) == 0
+	if memoable && token == sd.idTokenMemoRaw {
+		return sd.idTokenMemo
+	}
+
 	result := sd.manager.chunkManager.GetToken(
 		token,
 		compressed,
@@ -3024,11 +3070,14 @@ func (sd *SessionData) getIDTokenUnsafe() string {
 		IDTokenConfig,
 	)
 
+	validated := result.Token
 	if result.Error != nil {
-		return ""
+		validated = ""
 	}
-
-	return result.Token
+	if memoable {
+		sd.idTokenMemoRaw, sd.idTokenMemo = token, validated
+	}
+	return validated
 }
 
 // getRefreshTokenUnsafe retrieves the refresh token without acquiring locks.

session_access_token_nilrequest_test.go

@@ -0,0 +1,36 @@
+package traefikoidc
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"net/http/httptest"
+	"testing"
+)
+
+// A chunked store that cannot run (no request to bind chunk cookies to) must
+// leave the previous access token intact.
+func TestSetAccessTokenNilRequestKeepsOldToken(t *testing.T) {
+	sm, err := NewSessionManager("test-encryption-key-32-characters", false, "", "", 0, NewLogger("error"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	sess, err := sm.GetSession(httptest.NewRequest("GET", "/", nil))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(sess.returnToPoolSafely)
+
+	const old = "smallaccesstokenvaluevaluevalue"
+	sess.SetAccessToken(old)
+
+	blob := make([]byte, 3000)
+	if _, err := rand.Read(blob); err != nil {
+		t.Fatal(err)
+	}
+	sess.request = nil
+	sess.SetAccessToken(base64.StdEncoding.EncodeToString(blob))
+
+	if got := sess.GetAccessToken(); got != old {
+		t.Fatalf("old access token lost after a failed chunked store: %q", got)
+	}
+}

session_chunk_manager.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+	"unicode/utf8"
 
 	"github.com/gorilla/sessions"
 	"github.com/lukaszraczylo/traefikoidc/internal/pool"
@@ -89,9 +90,14 @@ type TokenRetrievalResult struct {
 // and error handling to ensure data integrity and prevent security vulnerabilities
 // throughout the process.
 type ChunkManager struct {
-	lastCleanup    time.Time
-	ctx            context.Context
-	mutex          *sync.RWMutex
+	lastCleanup time.Time
+	ctx         context.Context
+	mutex       *sync.RWMutex
+	// contentValid holds keys of tokens that passed every content-only check.
+	// Browsers resend the same cookie, and re-running those checks on every
+	// request dominated per-request cost under yaegi. Guarded by contentMu.
+	contentValid   map[string]tokenTimes
+	contentMu      sync.Mutex
 	cancel         context.CancelFunc
 	sessionMap     map[string]*SessionEntry
 	logger         *Logger
@@ -127,14 +133,15 @@ func NewChunkManager(logger *Logger) *ChunkManager {
 	ctx, cancel := context.WithCancel(context.Background())
 
 	cm := &ChunkManager{
-		logger:      logger,
-		mutex:       &sync.RWMutex{},
-		ctx:         ctx,
-		cancel:      cancel,
-		sessionMap:  make(map[string]*SessionEntry),
-		maxSessions: 200,              // CRITICAL FIX: Reduced from 1000 to 200 per instance
-		sessionTTL:  15 * time.Minute, // CRITICAL FIX: Reduced from 24h to 15 minutes
-		lastCleanup: time.Now(),
+		logger:       logger,
+		mutex:        &sync.RWMutex{},
+		ctx:          ctx,
+		cancel:       cancel,
+		sessionMap:   make(map[string]*SessionEntry),
+		contentValid: make(map[string]tokenTimes),
+		maxSessions:  200,              // CRITICAL FIX: Reduced from 1000 to 200 per instance
+		sessionTTL:   15 * time.Minute, // CRITICAL FIX: Reduced from 24h to 15 minutes
+		lastCleanup:  time.Now(),
 	}
 
 	// Start background cleanup routine
@@ -293,26 +300,38 @@ func (cm *ChunkManager) processSingleToken(token string, compressed bool, config
 // Returns:
 //   - TokenRetrievalResult with the validated token or validation error.
 func (cm *ChunkManager) validateToken(token string, config TokenConfig) TokenRetrievalResult {
-	if sizeErr := cm.validateTokenSize(token, config); sizeErr != nil {
-		return TokenRetrievalResult{Token: "", Error: sizeErr}
+	// Content-only checks depend on the token string alone, so a token that
+	// passed them once skips them. Expiry and freshness always run.
+	key := contentValidKey(token, config)
+	times, cached := cm.cachedTokenTimes(key)
+
+	if !cached {
+		if sizeErr := cm.validateTokenSize(token, config); sizeErr != nil {
+			return TokenRetrievalResult{Token: "", Error: sizeErr}
+		}
+
+		cm.validateChunkingEfficiency(token, config)
+
+		if contentErr := cm.validateTokenContent(token, config); contentErr != nil {
+			return TokenRetrievalResult{Token: "", Error: contentErr}
+		}
+		times = cm.tokenTimesOf(token)
 	}
 
-	cm.validateChunkingEfficiency(token, config)
-
-	if contentErr := cm.validateTokenContent(token, config); contentErr != nil {
-		return TokenRetrievalResult{Token: "", Error: contentErr}
-	}
-
-	if expErr := cm.validateTokenExpiration(token, config); expErr != nil {
+	if expErr := cm.validateTokenExpiration(times, config); expErr != nil {
 		return TokenRetrievalResult{Token: "", Error: expErr}
 	}
 
-	if freshnessErr := cm.validateTokenFreshness(token, config); freshnessErr != nil {
+	if freshnessErr := cm.validateTokenFreshness(times, config); freshnessErr != nil {
 		return TokenRetrievalResult{Token: "", Error: freshnessErr}
 	}
 
 	// Determine if token is opaque or JWT based on format
 	// JWT tokens have exactly 2 dots (3 parts: header.payload.signature)
+	if cached {
+		return TokenRetrievalResult{Token: token, Error: nil}
+	}
+
 	dotCount := strings.Count(token, ".")
 	isJWT := dotCount == 2
 
@@ -338,6 +357,7 @@ func (cm *ChunkManager) validateToken(token string, config TokenConfig) TokenRet
 		}
 	}
 
+	cm.markContentValid(key, times)
 	return TokenRetrievalResult{Token: token, Error: nil}
 }
 
@@ -350,6 +370,53 @@ func (cm *ChunkManager) validateToken(token string, config TokenConfig) TokenRet
 //
 // Returns:
 //   - TokenRetrievalResult with the reassembled token or error.
+//
+// tokenTimes holds a token's parsed exp and iat claims. They are part of the
+// token content, so a content-cache entry keeps them to avoid re-parsing the
+// payload on every request. The checks that use them still run each time.
+type tokenTimes struct {
+	exp, iat       *time.Time
+	expErr, iatErr error
+	jwt            bool
+}
+
+// tokenTimesOf parses exp and iat from a JWT-shaped token.
+func (cm *ChunkManager) tokenTimesOf(token string) tokenTimes {
+	if !strings.Contains(token, ".") {
+		return tokenTimes{}
+	}
+	t := tokenTimes{jwt: true}
+	t.exp, t.expErr = cm.extractJWTExpiration(token)
+	t.iat, t.iatErr = cm.extractJWTIssuedAt(token)
+	return t
+}
+
+// contentValidCacheMax bounds contentValid; the map is cleared when full.
+const contentValidCacheMax = 4096
+
+// contentValidKey keys a token by type and SHA-256 so the cache does not
+// retain token values.
+func contentValidKey(token string, config TokenConfig) string {
+	sum := sha256.Sum256([]byte(token))
+	return config.Type + ":" + string(sum[:])
+}
+
+func (cm *ChunkManager) cachedTokenTimes(key string) (tokenTimes, bool) {
+	cm.contentMu.Lock()
+	t, ok := cm.contentValid[key]
+	cm.contentMu.Unlock()
+	return t, ok
+}
+
+func (cm *ChunkManager) markContentValid(key string, t tokenTimes) {
+	cm.contentMu.Lock()
+	if len(cm.contentValid) >= contentValidCacheMax {
+		cm.contentValid = make(map[string]tokenTimes)
+	}
+	cm.contentValid[key] = t
+	cm.contentMu.Unlock()
+}
+
 func (cm *ChunkManager) processChunkedToken(chunks map[int]*sessions.Session, config TokenConfig) TokenRetrievalResult {
 	if len(chunks) > config.MaxChunks {
 		err := fmt.Errorf("too many %s token chunks (%d, max: %d)", config.Type, len(chunks), config.MaxChunks)
@@ -378,9 +445,10 @@ func (cm *ChunkManager) processChunkedToken(chunks map[int]*sessions.Session, co
 				// not clear cookies above n). token_total is the authoritative
 				// count; drop the excess rather than failing — which forced a
 				// re-auth and discarded the still-valid new token (R129).
-				n := len(chunks)
-				for i := total; i < n; i++ {
-					delete(chunks, i)
+				for i := range chunks {
+					if i >= total {
+						delete(chunks, i)
+					}
 				}
 			}
 			if len(chunks) < total {
@@ -504,7 +572,9 @@ func (cm *ChunkManager) validateJWTFormat(token string, tokenType string) error
 			return err
 		}
 
-		for _, char := range part {
+		// Byte loop: a multi-byte rune fails on its first byte either way.
+		for j := 0; j < len(part); j++ {
+			char := part[j]
 			if !((char >= 'A' && char <= 'Z') ||
 				(char >= 'a' && char <= 'z') ||
 				(char >= '0' && char <= '9') ||
@@ -717,9 +787,10 @@ func (cm *ChunkManager) validateTokenSanitization(token string, config TokenConf
 		return err
 	}
 
-	// Check for control characters (ASCII 0-31 and 127)
-	for i, char := range token {
-		if char < 32 || char == 127 {
+	// Check for control characters (ASCII 0-31 and 127). Byte loop: bytes of
+	// a multi-byte rune are >= 0x80, and i is a byte offset either way.
+	for i := 0; i < len(token); i++ {
+		if char := token[i]; char < 32 || char == 127 {
 			err := fmt.Errorf("%s token contains control character at position %d", config.Type, i)
 			return err
 		}
@@ -921,7 +992,13 @@ func (cm *ChunkManager) detectRepeatedCharacters(token string, config TokenConfi
 	currentRepeated := 1
 	var lastChar rune
 
-	for i, char := range token {
+	// Index loops, not range: under yaegi, ranging over a string allocates
+	// O(n²) bytes, which dominated per-request cost for 1-2 KB tokens.
+	for i := 0; i < len(token); {
+		char, size := rune(token[i]), 1
+		if char >= utf8.RuneSelf {
+			char, size = utf8.DecodeRuneInString(token[i:])
+		}
 		if i > 0 && char == lastChar {
 			currentRepeated++
 			if currentRepeated > maxRepeated {
@@ -931,6 +1008,7 @@ func (cm *ChunkManager) detectRepeatedCharacters(token string, config TokenConfi
 			currentRepeated = 1
 		}
 		lastChar = char
+		i += size
 	}
 
 	threshold := 20
@@ -941,8 +1019,13 @@ func (cm *ChunkManager) detectRepeatedCharacters(token string, config TokenConfi
 	}
 
 	charFreq := make(map[rune]int)
-	for _, char := range token {
+	for i := 0; i < len(token); {
+		char, size := rune(token[i]), 1
+		if char >= utf8.RuneSelf {
+			char, size = utf8.DecodeRuneInString(token[i:])
+		}
 		charFreq[char]++
+		i += size
 	}
 
 	tokenLen := len(token)
@@ -963,21 +1046,21 @@ func (cm *ChunkManager) detectRepeatedCharacters(token string, config TokenConfi
 // It extracts and checks JWT expiration claims to ensure tokens are not expired
 // and detects tokens with suspicious expiration times.
 // Parameters:
-//   - token: The token to check expiration for.
+//   - times: The token's parsed claims (see tokenTimesOf).
 //   - config: Token configuration for error context.
 //
 // Returns:
 //   - An error if the token is expired or has invalid expiration, nil if valid.
 //
 //nolint:unparam // error return kept for API consistency and future use
-func (cm *ChunkManager) validateTokenExpiration(token string, config TokenConfig) error {
-	if !strings.Contains(token, ".") {
+func (cm *ChunkManager) validateTokenExpiration(times tokenTimes, config TokenConfig) error {
+	if !times.jwt {
 		return nil
 	}
 
-	expiration, err := cm.extractJWTExpiration(token)
-	if err != nil {
-		cm.logger.Debugf("Could not extract expiration from %s token: %v", config.Type, err)
+	expiration := times.exp
+	if times.expErr != nil {
+		cm.logger.Debugf("Could not extract expiration from %s token: %v", config.Type, times.expErr)
 		return nil
 	}
 
@@ -1062,19 +1145,19 @@ func (cm *ChunkManager) extractJWTExpiration(token string) (*time.Time, error) {
 // It examines the 'iat' (issued at) claim to detect tokens issued too far
 // in the future or suspiciously old tokens that might indicate replay attacks.
 // Parameters:
-//   - token: The token to check freshness for.
+//   - times: The token's parsed claims (see tokenTimesOf).
 //   - config: Token configuration for error context.
 //
 // Returns:
 //   - An error if the token freshness is suspicious, nil if acceptable.
-func (cm *ChunkManager) validateTokenFreshness(token string, config TokenConfig) error {
-	if !strings.Contains(token, ".") {
+func (cm *ChunkManager) validateTokenFreshness(times tokenTimes, config TokenConfig) error {
+	if !times.jwt {
 		return nil
 	}
 
-	issuedAt, err := cm.extractJWTIssuedAt(token)
-	if err != nil {
-		cm.logger.Debugf("Could not extract issued time from %s token: %v", config.Type, err)
+	issuedAt := times.iat
+	if times.iatErr != nil {
+		cm.logger.Debugf("Could not extract issued time from %s token: %v", config.Type, times.iatErr)
 		return nil
 	}
 

session_incoming_scheme_test.go

@@ -0,0 +1,41 @@
+package traefikoidc
+
+import (
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/lukaszraczylo/traefikoidc/internal/utils"
+)
+
+// A deep link longer than the cap must not be persisted into the cookies.
+func TestSetIncomingPathCapsLength(t *testing.T) {
+	sm, err := NewSessionManager("test-encryption-key-32-characters", false, "", "", 0, NewLogger("error"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	sess, err := sm.GetSession(httptest.NewRequest("GET", "/", nil))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(sess.returnToPoolSafely)
+
+	sess.SetIncomingPath("/ok?a=1")
+	if got := sess.GetIncomingPath(); got != "/ok?a=1" {
+		t.Fatalf("short path changed: %q", got)
+	}
+	sess.SetIncomingPath("/x?" + strings.Repeat("q", maxIncomingPathLen+1))
+	if got := sess.GetIncomingPath(); got != "" {
+		t.Fatalf("oversized path stored (%d bytes)", len(got))
+	}
+}
+
+func TestDetermineSchemeCaseInsensitive(t *testing.T) {
+	for in, want := range map[string]string{"HTTPS": "https", "Https": "https", "HTTP": "http", "https": "https"} {
+		r := httptest.NewRequest("GET", "/", nil)
+		r.Header.Set("X-Forwarded-Proto", in)
+		if got := utils.DetermineScheme(r, false); got != want {
+			t.Errorf("X-Forwarded-Proto %q -> %q, want %q", in, got, want)
+		}
+	}
+}

settings.go

@@ -659,6 +659,24 @@ func (c *Config) Validate() error {
 		return fmt.Errorf("sessionMaxAge is too large; must be at most %d seconds", math.MaxInt64/int64(time.Second))
 	}
 
+	// Bearer durations are int64 seconds * time.Second at startup (main.go); an
+	// unbounded value wraps negative or to zero and disables the age check
+	// and failure throttle.
+	for name, v := range map[string]int64{
+		"maxTokenAgeSeconds":          c.MaxTokenAgeSeconds,
+		"bearerFailureWindowSeconds":  int64(c.BearerFailureWindowSeconds),
+		"bearerFailurePenaltySeconds": int64(c.BearerFailurePenaltySeconds),
+	} {
+		if v > maxDurationSeconds {
+			return fmt.Errorf("%s is too large; must be at most %d seconds", name, maxDurationSeconds)
+		}
+	}
+	// The throttle sweep cutoff adds window and penalty.
+	if int64(c.BearerFailureWindowSeconds) > 0 && int64(c.BearerFailurePenaltySeconds) > 0 &&
+		int64(c.BearerFailureWindowSeconds)+int64(c.BearerFailurePenaltySeconds) > maxDurationSeconds {
+		return fmt.Errorf("bearerFailureWindowSeconds plus bearerFailurePenaltySeconds is too large")
+	}
+
 	// Validate audience if specified
 	if c.Audience != "" {
 		// Validate audience format - should be a valid identifier or URL
@@ -954,6 +972,7 @@ func isValidSecureURL(s string) bool {
 // isLoopbackHost reports whether host is "localhost" or a loopback IP literal
 // (127.0.0.0/8 or ::1).
 func isLoopbackHost(host string) bool {
+	host = canonicalHost(host)
 	if strings.EqualFold(host, "localhost") {
 		return true
 	}
@@ -1227,6 +1246,14 @@ func (c *Config) GetSecurityHeadersApplier() func(http.ResponseWriter, *http.Req
 }
 
 // isOriginAllowed checks if an origin is in the allowed list
+const (
+	// maxDurationSeconds is the largest whole-second value whose
+	// time.Duration product with time.Second does not overflow int64.
+	maxDurationSeconds = math.MaxInt64 / int64(time.Second)
+	// maxRedisPoolSize bounds the eagerly allocated connection channel.
+	maxRedisPoolSize = 10000
+)
+
 // Validate checks if the Redis configuration is valid
 func (rc *RedisConfig) Validate() error {
 	if !rc.Enabled {
@@ -1253,6 +1280,9 @@ func (rc *RedisConfig) Validate() error {
 	if rc.PoolSize < 0 {
 		return fmt.Errorf("pool size cannot be negative")
 	}
+	if rc.PoolSize > maxRedisPoolSize {
+		return fmt.Errorf("pool size is too large; must be at most %d", maxRedisPoolSize)
+	}
 	if rc.ConnectTimeout < 0 {
 		return fmt.Errorf("connect timeout cannot be negative")
 	}
@@ -1286,6 +1316,21 @@ func (rc *RedisConfig) Validate() error {
 		return fmt.Errorf("health check interval cannot be negative")
 	}
 
+	// Seconds become time.Duration (x * time.Second) and the threshold is
+	// narrowed to int32 in the breaker; out-of-range values wrap, which
+	// panics time.NewTicker or trips the breaker on the first failure.
+	for name, v := range map[string]int{
+		"health check interval":   rc.HealthCheckInterval,
+		"circuit breaker timeout": rc.CircuitBreakerTimeout,
+	} {
+		if int64(v) > maxDurationSeconds {
+			return fmt.Errorf("%s is too large; must be at most %d seconds", name, maxDurationSeconds)
+		}
+	}
+	if rc.CircuitBreakerThreshold > math.MaxInt32 {
+		return fmt.Errorf("circuit breaker threshold is too large; must be at most %d", math.MaxInt32)
+	}
+
 	return nil
 }
 

settings_duration_bounds_test.go

@@ -0,0 +1,73 @@
+package traefikoidc
+
+import (
+	"math"
+	"testing"
+	"time"
+)
+
+func boundsTestConfig() *Config {
+	cfg := CreateConfig()
+	cfg.ProviderURL = "https://auth.example.com"
+	cfg.CallbackURL = "/callback"
+	cfg.ClientID = "test-client"
+	cfg.ClientSecret = "test-client-secret"
+	cfg.SessionEncryptionKey = "test-encryption-key-32-bytes-long!!"
+	return cfg
+}
+
+const maxWholeSeconds = math.MaxInt64 / int64(time.Second)
+
+func TestConfigValidateRejectsDurationOverflow(t *testing.T) {
+	cases := map[string]func(c *Config){
+		"maxTokenAgeSeconds wraps negative": func(c *Config) { c.MaxTokenAgeSeconds = maxWholeSeconds + 1 },
+		"maxTokenAgeSeconds wraps to zero":  func(c *Config) { c.MaxTokenAgeSeconds = 1 << 55 },
+		"bearerFailureWindowSeconds":        func(c *Config) { c.BearerFailureWindowSeconds = int(maxWholeSeconds + 1) },
+		"bearerFailurePenaltySeconds":       func(c *Config) { c.BearerFailurePenaltySeconds = int(maxWholeSeconds + 1) },
+	}
+	for name, mutate := range cases {
+		t.Run(name, func(t *testing.T) {
+			cfg := boundsTestConfig()
+			mutate(cfg)
+			if err := cfg.Validate(); err == nil {
+				t.Fatal("Validate accepted an overflowing duration")
+			}
+		})
+	}
+	t.Run("max exact value still valid", func(t *testing.T) {
+		cfg := boundsTestConfig()
+		cfg.MaxTokenAgeSeconds = maxWholeSeconds
+		if err := cfg.Validate(); err != nil {
+			t.Fatalf("boundary value rejected: %v", err)
+		}
+	})
+}
+
+func TestRedisConfigValidateRejectsOverflowAndHugePool(t *testing.T) {
+	base := func() *RedisConfig {
+		rc := &RedisConfig{Enabled: true, Address: "localhost:6379"}
+		return rc
+	}
+	cases := map[string]func(rc *RedisConfig){
+		"healthCheckInterval wraps to zero": func(rc *RedisConfig) { rc.HealthCheckInterval = 1 << 55 },
+		"circuitBreakerTimeout wraps":       func(rc *RedisConfig) { rc.CircuitBreakerTimeout = int(maxWholeSeconds + 1) },
+		"circuitBreakerThreshold narrows":   func(rc *RedisConfig) { rc.CircuitBreakerThreshold = math.MaxInt32 + 1 },
+		"poolSize absurd":                   func(rc *RedisConfig) { rc.PoolSize = 1_000_000_000 },
+	}
+	for name, mutate := range cases {
+		t.Run(name, func(t *testing.T) {
+			rc := base()
+			mutate(rc)
+			if err := rc.Validate(); err == nil {
+				t.Fatal("Validate accepted an unsafe value")
+			}
+		})
+	}
+	t.Run("defaults and sane values stay valid", func(t *testing.T) {
+		rc := base()
+		rc.PoolSize, rc.CircuitBreakerThreshold, rc.HealthCheckInterval = 50, 5, 30
+		if err := rc.Validate(); err != nil {
+			t.Fatalf("sane config rejected: %v", err)
+		}
+	})
+}

template_validation.go

@@ -22,6 +22,7 @@ var allowedRootTokenFields = map[string]bool{
 var validateTemplateParseFuncs = map[string]any{
 	"get":     struct{}{},
 	"default": struct{}{},
+	"toJson":  struct{}{},
 }
 
 // claimsWhitelist returns the effective set of claim field names a header
@@ -183,12 +184,14 @@ func (v *templateValidator) validateCommand(cmd *parse.CommandNode, dotIsRoot bo
 	return nil
 }
 
-// validateFunctionCall allows only get/default. get's map argument must be a
+// validateFunctionCall allows only get/default/toJson. get's map argument must be a
 // claims reference (never the root) and default's arguments are validated as
 // values; the runtime get additionally enforces the key whitelist.
 func (v *templateValidator) validateFunctionCall(name string, args []parse.Node, dotIsRoot bool) error {
 	switch name {
-	case "default":
+	case "default", "toJson":
+		// toJson only serializes what its (validated) arguments or piped input
+		// already expose; it cannot reach anything a direct reference could not.
 		for _, arg := range args {
 			if err := v.validateValue(arg, dotIsRoot); err != nil {
 				return err

tojson_template_test.go

@@ -0,0 +1,286 @@
+package traefikoidc
+
+import (
+	"encoding/json"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"text/template"
+)
+
+// renderHeaderTemplate runs tmplStr through the same validator, funcMap and
+// applyHeaderTemplates path production uses. validateErr is the static-validation
+// error; got is the forwarded header value ("" when absent or dropped).
+func renderHeaderTemplate(t *testing.T, tmplStr string, extraClaims []string, claims map[string]interface{}) (got string, validateErr error) {
+	t.Helper()
+	allowed := claimsWhitelist(extraClaims)
+	if err := validateTemplateSecure(tmplStr, allowed); err != nil {
+		return "", err
+	}
+	tmpl, err := template.New("X-Test").Funcs(headerTemplateFuncMap(allowed)).Option("missingkey=zero").Parse(tmplStr)
+	if err != nil {
+		t.Fatalf("validated template failed to parse: %v", err)
+	}
+	o := &TraefikOidc{logger: NewLogger("error"), headerTemplates: map[string]*template.Template{"X-Test": tmpl}}
+	req := httptest.NewRequest("GET", "/", nil)
+	o.applyHeaderTemplates(req, &principal{Claims: claims, AccessToken: "AT-SECRET", IDToken: "IDT-SECRET", RefreshToken: "RT-SECRET"})
+	return req.Header.Get("X-Test"), nil
+}
+
+func TestToJson_ObjectClaimRoundTrips(t *testing.T) {
+	claims := map[string]interface{}{
+		"tenant": map[string]interface{}{"id": "t-1", "plan": "pro", "flags": []interface{}{"a", "b"}, "n": 3.0, "ok": true, "nil": nil},
+	}
+	for _, tmpl := range []string{
+		`{{ get .Claims "tenant" | toJson }}`,
+		`{{ toJson (get .Claims "tenant") }}`,
+		`{{ toJson .Claims.tenant }}`,
+		`{{ with .Claims.tenant }}{{ toJson . }}{{ end }}`,
+		`{{ $t := .Claims.tenant }}{{ toJson $t }}`,
+		`{{ toJson $.Claims.tenant }}`,
+	} {
+		got, err := renderHeaderTemplate(t, tmpl, []string{"tenant"}, claims)
+		if err != nil {
+			t.Fatalf("%s: unexpected validation error: %v", tmpl, err)
+		}
+		var back map[string]interface{}
+		if err := json.Unmarshal([]byte(got), &back); err != nil {
+			t.Fatalf("%s: output %q is not valid JSON: %v", tmpl, got, err)
+		}
+		if back["id"] != "t-1" || back["plan"] != "pro" || back["n"] != 3.0 || back["ok"] != true {
+			t.Fatalf("%s: round trip mismatch: %q", tmpl, got)
+		}
+	}
+}
+
+func TestToJson_ValueTypes(t *testing.T) {
+	claims := map[string]interface{}{
+		"groups": []interface{}{"admin", "users"},
+		"email":  "[email protected]",
+		"exp":    1700000000.0,
+		"role":   "",
+	}
+	cases := []struct{ name, tmpl, want string }{
+		{"array", `{{ toJson .Claims.groups }}`, `["admin","users"]`},
+		{"string", `{{ toJson .Claims.email }}`, `"[email protected]"`},
+		{"number", `{{ toJson .Claims.exp }}`, `1700000000`},
+		{"missing claim skips header", `{{ toJson .Claims.department }}`, ``},
+		{"missing via get skips header", `{{ get .Claims "department" | toJson }}`, ``},
+		{"empty string skips header", `{{ toJson .Claims.role }}`, ``},
+		{"literal string", `{{ toJson "x" }}`, `"x"`},
+		{"literal number", `{{ toJson 5 }}`, `5`},
+		{"composes with surrounding text", `v={{ toJson .Claims.groups }};`, `v=["admin","users"];`},
+	}
+	for _, c := range cases {
+		got, err := renderHeaderTemplate(t, c.tmpl, nil, claims)
+		if err != nil {
+			t.Fatalf("%s: unexpected validation error: %v", c.name, err)
+		}
+		if got != c.want {
+			t.Errorf("%s: got %q want %q", c.name, got, c.want)
+		}
+	}
+}
+
+func TestToJson_EmptyAndNilContainers(t *testing.T) {
+	claims := map[string]interface{}{
+		"realm_access": map[string]interface{}{},
+		"groups":       []interface{}{},
+	}
+	if got, _ := renderHeaderTemplate(t, `{{ toJson .Claims.realm_access }}`, nil, claims); got != `{}` {
+		t.Errorf("empty object: got %q", got)
+	}
+	if got, _ := renderHeaderTemplate(t, `{{ toJson .Claims.groups }}`, nil, claims); got != `[]` {
+		t.Errorf("empty array: got %q", got)
+	}
+	if got, _ := renderHeaderTemplate(t, `{{ toJson .Claims.groups }}`, nil, nil); got != `` {
+		t.Errorf("nil claims: got %q", got)
+	}
+}
+
+func TestToJson_UnmarshalableValueDropsHeader(t *testing.T) {
+	fn := headerTemplateFuncMap(nil)["toJson"].(func(interface{}) (string, error))
+	if _, err := fn(make(chan int)); err == nil {
+		t.Fatal("expected error for unmarshalable value")
+	}
+	// A non-finite float is the only way a claim map could carry one in.
+	if _, err := fn(map[string]interface{}{"x": func() {}}); err == nil {
+		t.Fatal("expected error for func value")
+	}
+}
+
+// Security: toJson must not widen what a template can reach.
+func TestToJson_SecurityBoundary(t *testing.T) {
+	claims := map[string]interface{}{
+		"email":  "[email protected]",
+		"secret": "NOT-WHITELISTED",
+		"tenant": map[string]interface{}{"id": "t"},
+	}
+	rejected := []string{
+		`{{ toJson . }}`,
+		`{{ toJson $ }}`,
+		`{{ toJson .Claims }}`,
+		`{{ toJson $.Claims }}`,
+		`{{ .Claims | toJson }}`,
+		`{{ toJson .Claims.secret }}`,
+		`{{ toJson $.Claims.secret }}`,
+		`{{ toJson .AccessToken }}{{ toJson .Claims }}`,
+		`{{ get .Claims "secret" | toJson }}`,
+		`{{ toJson (get . "AccessToken") }}`,
+		`{{ get . "Claims" | toJson }}`,
+		`{{ with .Claims }}{{ toJson . }}{{ end }}`,
+		`{{ range .Claims }}{{ toJson . }}{{ end }}`,
+		`{{ toJson (index .Claims "secret") }}`,
+		`{{ toJson (printf "%v" .Claims) }}`,
+		`{{ toJson (call .Claims) }}`,
+		`{{ tojson .Claims.email }}`,
+		`{{ toJSON .Claims.email }}`,
+		`{{ toJson | js }}`,
+	}
+	for _, tmpl := range rejected {
+		if got, err := renderHeaderTemplate(t, tmpl, nil, claims); err == nil {
+			t.Errorf("%s: must be rejected by validation, rendered %q", tmpl, got)
+		}
+	}
+
+	// Dynamic key: static validation cannot see it, the runtime whitelist must.
+	dyn := `{{ get .Claims .Claims.email | toJson }}`
+	if got, err := renderHeaderTemplate(t, dyn, nil, map[string]interface{}{"email": "secret", "secret": "LEAK"}); err != nil || strings.Contains(got, "LEAK") {
+		t.Errorf("dynamic key leaked a non-whitelisted claim: err=%v got=%q", err, got)
+	}
+}
+
+// Security: tokens and the claims map never appear in output, even from a
+// validated template that serializes a whitelisted claim.
+func TestToJson_NoTokenLeak(t *testing.T) {
+	claims := map[string]interface{}{"tenant": map[string]interface{}{"id": "t"}}
+	got, err := renderHeaderTemplate(t, `{{ toJson .Claims.tenant }}`, []string{"tenant"}, claims)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, s := range []string{"AT-SECRET", "IDT-SECRET", "RT-SECRET"} {
+		if strings.Contains(got, s) {
+			t.Fatalf("token %s leaked into %q", s, got)
+		}
+	}
+}
+
+// Security: a non-whitelisted claim stays unreachable until the operator opts
+// in via allowedClaims, with or without toJson.
+func TestToJson_RequiresAllowedClaims(t *testing.T) {
+	claims := map[string]interface{}{"tenant": map[string]interface{}{"id": "t"}}
+	if _, err := renderHeaderTemplate(t, `{{ toJson .Claims.tenant }}`, nil, claims); err == nil {
+		t.Error("direct reference to non-whitelisted claim must be rejected")
+	}
+	got, err := renderHeaderTemplate(t, `{{ get .Claims "tenant" | toJson }}`, nil, claims)
+	if err == nil {
+		t.Errorf("literal get key outside whitelist must be rejected, rendered %q", got)
+	}
+}
+
+// Security: hostile claim content must not produce header injection.
+func TestToJson_HeaderInjectionHardening(t *testing.T) {
+	cases := []struct {
+		name  string
+		value interface{}
+		// forwarded reports whether the header is expected to reach upstream.
+		forwarded bool
+	}{
+		{"CRLF is escaped to \\r\\n", map[string]interface{}{"x": "a\r\nX-Evil: 1"}, true},
+		{"NUL and control chars escaped", map[string]interface{}{"x": "a\x00\x07b"}, true},
+		{"LS/PS escaped", map[string]interface{}{"x": "a

b"}, true},
+		{"HTML chars escaped", map[string]interface{}{"x": "<script>&"}, true},
+		{"quote and backslash escaped", map[string]interface{}{"x": `"\`}, true},
+		{"bidi override dropped by sanitizer", map[string]interface{}{"x": "a\u202Eb"}, false},
+		{"bidi isolate dropped by sanitizer", map[string]interface{}{"x": "a\u2066b"}, false},
+		{"oversize dropped by sanitizer", map[string]interface{}{"x": strings.Repeat("A", headerTemplateMaxLen)}, false},
+	}
+	for _, c := range cases {
+		got, err := renderHeaderTemplate(t, `{{ toJson .Claims.realm_access }}`, nil, map[string]interface{}{"realm_access": c.value})
+		if err != nil {
+			t.Fatalf("%s: %v", c.name, err)
+		}
+		if !c.forwarded {
+			if got != "" {
+				t.Errorf("%s: tainted value must be dropped, got %d bytes", c.name, len(got))
+			}
+			continue
+		}
+		if got == "" {
+			t.Errorf("%s: safe escaped JSON must be forwarded", c.name)
+			continue
+		}
+		for _, r := range got {
+			if r < 0x20 || r == 0x7f || r == 0x2028 || r == 0x2029 {
+				t.Errorf("%s: raw control rune %U in %q", c.name, r, got)
+			}
+		}
+		if strings.ContainsAny(got, "<>&") {
+			t.Errorf("%s: unescaped HTML char in %q", c.name, got)
+		}
+		var back map[string]interface{}
+		if err := json.Unmarshal([]byte(got), &back); err != nil {
+			t.Errorf("%s: not valid JSON: %v", c.name, err)
+		}
+	}
+}
+
+// Default-preserving: existing templates are unaffected and toJson is not
+// available to anything but validated header templates.
+func TestToJson_ExistingTemplatesUnchanged(t *testing.T) {
+	claims := map[string]interface{}{"email": "[email protected]", "groups": []interface{}{"x", "y"}}
+	got, err := renderHeaderTemplate(t, `{{ .Claims.email }}|{{range $i, $e := .Claims.groups}}{{if $i}},{{end}}{{$e}}{{end}}|{{ default "d" .Claims.role }}`, nil, claims)
+	if err != nil || got != "[email protected]|x,y|d" {
+		t.Fatalf("got %q err=%v", got, err)
+	}
+	if _, ok := headerTemplateFuncMap(nil)["toJson"]; !ok {
+		t.Fatal("toJson missing from func map")
+	}
+	for _, name := range []string{"env", "expandenv", "printf", "call", "index", "js"} {
+		if _, ok := headerTemplateFuncMap(nil)[name]; ok {
+			t.Errorf("%s must not be exposed", name)
+		}
+	}
+}
+
+func TestToJson_ConfigValidate(t *testing.T) {
+	cfg := issue149BaseConfig()
+	cfg.AllowedClaims = []string{"tenant"}
+	cfg.Headers = []TemplatedHeader{{Name: "X-Tenant", Value: `{{ get .Claims "tenant" | toJson }}`}}
+	if err := cfg.Validate(); err != nil {
+		t.Fatalf("toJson header must validate: %v", err)
+	}
+	cfg.Headers = []TemplatedHeader{{Name: "X-All", Value: `{{ toJson .Claims }}`}}
+	if err := cfg.Validate(); err == nil {
+		t.Fatal("toJson of whole Claims must fail validation")
+	}
+}
+
+// Oversize output is operator-actionable, so it logs at error level (name and
+// size limit only, never the value); other sanitizer drops stay at debug.
+func TestToJson_OversizeLogsError(t *testing.T) {
+	run := func(claim map[string]interface{}) string {
+		var buf strings.Builder
+		logger := NewLogger("debug")
+		logger.logError.SetOutput(&buf)
+		tmpl := template.Must(template.New("X-Test").Funcs(headerTemplateFuncMap(nil)).Parse(`{{ toJson .Claims.realm_access }}`))
+		o := &TraefikOidc{logger: logger, headerTemplates: map[string]*template.Template{"X-Test": tmpl}}
+		req := httptest.NewRequest("GET", "/", nil)
+		o.applyHeaderTemplates(req, &principal{Claims: map[string]interface{}{"realm_access": claim}})
+		if req.Header.Get("X-Test") != "" {
+			t.Fatal("tainted header must be dropped")
+		}
+		return buf.String()
+	}
+	big := strings.Repeat("S3CRET", headerTemplateMaxLen)
+	out := run(map[string]interface{}{"x": big})
+	if !strings.Contains(out, "X-Test") || !strings.Contains(out, "exceeds") {
+		t.Errorf("oversize must log an error naming the header, got %q", out)
+	}
+	if strings.Contains(out, "S3CRET") {
+		t.Error("error log must not contain the value")
+	}
+	if out := run(map[string]interface{}{"x": "a\u202Eb"}); out != "" {
+		t.Errorf("non-length sanitizer drop must not log at error level, got %q", out)
+	}
+}

token_cache_namespace_test.go

@@ -0,0 +1,69 @@
+package traefikoidc
+
+import (
+	"testing"
+	"time"
+)
+
+func newNSCache(t *testing.T) *UniversalCache {
+	t.Helper()
+	c := NewUniversalCache(UniversalCacheConfig{Type: CacheTypeToken, MaxSize: 100, DefaultTTL: time.Hour, CleanupInterval: time.Hour})
+	t.Cleanup(func() { _ = c.Close() })
+	return c
+}
+
+// A verdict stored by one middleware instance must not satisfy another
+// instance that verifies against a different client or audience.
+func TestTokenCacheIsolatedPerInstanceNamespace(t *testing.T) {
+	shared := newNSCache(t)
+	a := &TokenCache{cache: shared}
+	b := &TokenCache{cache: shared}
+	a.SetNamespace("https://idp|app-a|app-a")
+	b.SetNamespace("https://idp|app-b|app-b")
+
+	a.Set("tok", map[string]interface{}{"sub": "u"}, time.Minute)
+	if _, ok := b.Get("tok"); ok {
+		t.Fatal("instance B hit a verdict cached by instance A")
+	}
+	if _, ok := a.Get("tok"); !ok {
+		t.Fatal("instance A lost its own verdict")
+	}
+	a.Delete("tok")
+	if _, ok := a.Get("tok"); ok {
+		t.Fatal("Delete did not remove the namespaced entry")
+	}
+}
+
+func TestTokenCacheNamespaceFollowsDCR(t *testing.T) {
+	shared := newNSCache(t)
+	tc := &TokenCache{cache: shared}
+	tc.SetNamespace("p|old|old")
+	tc.Set("tok", map[string]interface{}{"sub": "u"}, time.Minute)
+	tc.SetNamespace("p|new|new")
+	if _, ok := tc.Get("tok"); ok {
+		t.Fatal("verdict cached under the old client survived a namespace change")
+	}
+}
+
+func TestTokenCacheEmptyNamespaceKeepsLegacyKey(t *testing.T) {
+	shared := newNSCache(t)
+	a := &TokenCache{cache: shared}
+	b := &TokenCache{cache: shared}
+	a.Set("tok", map[string]interface{}{"sub": "u"}, time.Minute)
+	if _, ok := b.Get("tok"); !ok {
+		t.Fatal("namespace-less caches must keep sharing the legacy key")
+	}
+}
+
+func TestIntrospectionKeyScopedPerInstance(t *testing.T) {
+	a := &TraefikOidc{tokenCache: &TokenCache{}}
+	b := &TraefikOidc{tokenCache: &TokenCache{}}
+	a.tokenCache.SetNamespace("p|app-a|app-a")
+	b.tokenCache.SetNamespace("p|app-b|app-b")
+	if a.introspectionKey("tok") == b.introspectionKey("tok") {
+		t.Fatal("different instances share an introspection cache key")
+	}
+	if got := (&TraefikOidc{}).introspectionKey("tok"); got != "tok" {
+		t.Fatalf("namespace-less key = %q, want raw token", got)
+	}
+}

token_introspection.go

@@ -53,7 +53,7 @@ type IntrospectionResponse struct {
 func (t *TraefikOidc) introspectToken(token string) (*IntrospectionResponse, error) {
 	// Check cache first
 	if t.introspectionCache != nil {
-		if cached, found := t.introspectionCache.Get(token); found {
+		if cached, found := t.introspectionCache.Get(t.introspectionKey(token)); found {
 			if response, ok := cached.(*IntrospectionResponse); ok {
 				t.logger.Debugf("Using cached introspection result for token")
 				return response, nil
@@ -173,7 +173,7 @@ func (t *TraefikOidc) introspectToken(token string) (*IntrospectionResponse, err
 				cacheDuration = untilExp
 			}
 		}
-		t.introspectionCache.Set(token, &introspectionResp, cacheDuration)
+		t.introspectionCache.Set(t.introspectionKey(token), &introspectionResp, cacheDuration)
 		t.logger.Debugf("Cached introspection result for %v", cacheDuration)
 	}
 
@@ -280,3 +280,12 @@ func (t *TraefikOidc) validateOpaqueToken(token string) error {
 	t.logger.Debugf("Opaque token validation successful via introspection")
 	return nil
 }
+
+// introspectionKey scopes an introspection verdict to this instance's
+// provider, client and audience, like the verified-token cache.
+func (t *TraefikOidc) introspectionKey(token string) string {
+	if ns := t.tokenCache.Namespace(); ns != "" {
+		return ns + "|" + token
+	}
+	return token
+}

token_manager.go

@@ -812,7 +812,7 @@ func (t *TraefikOidc) RevokeToken(token string) {
 	// from the introspection cache after revocation. Next request
 	// re-introspects and sees active=false.
 	if t.introspectionCache != nil {
-		t.introspectionCache.Delete(token)
+		t.introspectionCache.Delete(t.introspectionKey(token))
 	}
 
 	d := blacklistDuration(token)

token_validation_rs.go

@@ -15,6 +15,7 @@ package traefikoidc
 import (
 	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"strings"
 	"time"
 )
@@ -266,8 +267,7 @@ func (t *TraefikOidc) validateStandardTokensRS(rs *requestState) (bool, bool, bo
 	var accessVerifyErr error
 	if err := t.verifyToken(rs.accessToken); err != nil {
 		accessVerifyErr = err
-		errMsg := err.Error()
-		if strings.Contains(errMsg, "invalid audience") || strings.Contains(errMsg, "audience") {
+		if errors.Is(err, errInvalidAudience) {
 			if t.strictAudienceValidation {
 				if rs.refreshToken != "" {
 					return false, true, false

types.go

@@ -111,6 +111,9 @@ type TraefikOidc struct {
 	// recovery attempt. Stored atomically so the hot ServeHTTP path can
 	// throttle retries without acquiring metadataRetryMutex on every request.
 	lastMetadataRetryNano int64
+	// initWaiters counts requests parked on initComplete; bounded by
+	// maxInitWaiters so a boot-time flood cannot hold unbounded connections.
+	initWaiters int32
 	// firstRequestStarted is 0 until the very first non-health request fires
 	// the background-task bootstrap; then it flips to 1 via CAS. Replaces the
 	// firstRequestMutex + firstRequestReceived combo which previously took
@@ -224,6 +227,7 @@ type TraefikOidc struct {
 	dcrMu                     sync.Mutex
 	shutdownOnce              sync.Once
 	sessionInvalidationCache  CacheInterface
+	frontchannelMarkers       markerQuota
 	refreshResultCache        CacheInterface
 	minimalHeaders            bool
 	stripAuthCookies          bool

universal_cache.go

@@ -380,6 +380,10 @@ func (c *UniversalCache) setLocalLocked(key string, value interface{}, ttl time.
 		growth = size - existing.Size
 	}
 
+	if c.rejectOversized(key, size) {
+		return
+	}
+
 	// Check memory limits
 	if c.config.MaxMemoryBytes > 0 {
 		// Evict items if necessary to make room
@@ -712,6 +716,9 @@ func (c *UniversalCache) getLocal(key string) (interface{}, bool) {
 			if gracePeriod, ok := item.Metadata["grace_period_active"].(bool); ok && gracePeriod {
 				if c.shouldExtendGracePeriod(item, now) {
 					newExpiry := c.calculateNewExpiry(item, now)
+					if _, set := item.Metadata[graceOriginKey]; !set {
+						item.Metadata[graceOriginKey] = item.ExpiresAt
+					}
 					item.ExpiresAt = newExpiry
 					c.logger.Infof("UniversalCache[%s]: Extended grace period for key=%s until %v",
 						c.config.Type, key, newExpiry)
@@ -915,11 +922,29 @@ func (c *UniversalCache) evictOldest() {
 	}
 }
 
+// rejectOversized drops a value larger than the whole memory cap instead of
+// flushing every other entry to fit it. A stale copy under the key is removed.
+// Caller holds c.mu.
+func (c *UniversalCache) rejectOversized(key string, size int64) bool {
+	if c.config.MaxMemoryBytes <= 0 || size <= c.config.MaxMemoryBytes {
+		return false
+	}
+	if existing, ok := c.items[key]; ok {
+		c.removeItem(key, existing)
+	}
+	c.logger.Infof("UniversalCache[%s]: dropped oversized value key=%s size=%d cap=%d",
+		c.config.Type, key, size, c.config.MaxMemoryBytes)
+	return true
+}
+
 // SetMaxSize sets the maximum size and evicts items if necessary
 func (c *UniversalCache) SetMaxSize(newSize int) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
+	if newSize < 1 {
+		newSize = 1 // a non-positive bound would spin the eviction loop forever
+	}
 	oldSize := c.config.MaxSize
 	c.config.MaxSize = newSize
 
@@ -1021,6 +1046,9 @@ func (c *UniversalCache) estimateSize(value interface{}) int64 {
 	}
 }
 
+// graceOriginKey holds the item's first expiry once grace has started.
+const graceOriginKey = "grace_origin"
+
 // shouldExtendGracePeriod determines if grace period should be extended
 func (c *UniversalCache) shouldExtendGracePeriod(item *CacheItem, now time.Time) bool {
 	if c.config.MetadataConfig == nil {
@@ -1040,8 +1068,12 @@ func (c *UniversalCache) shouldExtendGracePeriod(item *CacheItem, now time.Time)
 		}
 	}
 
-	// Calculate how long since the item originally expired
-	timeSinceExpiry := now.Sub(item.ExpiresAt)
+	// Measure from the first expiry: later extensions overwrite ExpiresAt.
+	origin := item.ExpiresAt
+	if o, ok := item.Metadata[graceOriginKey].(time.Time); ok {
+		origin = o
+	}
+	timeSinceExpiry := now.Sub(origin)
 	return timeSinceExpiry <= maxGrace
 }
 
@@ -1523,6 +1555,10 @@ func (c *UniversalCache) updateLocalCache(key string, value interface{}, ttl tim
 		growth = size - existing.Size
 	}
 
+	if c.rejectOversized(key, size) {
+		return nil
+	}
+
 	// Check memory limits
 	if c.config.MaxMemoryBytes > 0 {
 		for c.currentMemory+growth > c.config.MaxMemoryBytes && c.lruList.Len() > 0 {

universal_cache_bounds_test.go

@@ -0,0 +1,88 @@
+package traefikoidc
+
+import (
+	"math"
+	"testing"
+	"time"
+)
+
+func newBoundsCache(t *testing.T, cfg UniversalCacheConfig) *UniversalCache {
+	t.Helper()
+	cfg.CleanupInterval = time.Hour
+	if cfg.DefaultTTL == 0 {
+		cfg.DefaultTTL = time.Hour
+	}
+	c := NewUniversalCache(cfg)
+	t.Cleanup(func() { _ = c.Close() })
+	return c
+}
+
+// Grace extensions must stay within MaxGracePeriod of the ORIGINAL expiry.
+func TestGraceNeverServesPastOriginalExpiryBound(t *testing.T) {
+	c := newBoundsCache(t, UniversalCacheConfig{
+		Type: CacheTypeMetadata, MaxSize: 10,
+		MetadataConfig: &MetadataCacheConfig{
+			GracePeriod: 20 * time.Millisecond, ExtendedGracePeriod: 20 * time.Millisecond,
+			MaxGracePeriod: 100 * time.Millisecond, SecurityCriticalMaxGracePeriod: 100 * time.Millisecond,
+		},
+	})
+	if err := c.Set("k", "v", 10*time.Millisecond); err != nil {
+		t.Fatal(err)
+	}
+	c.ActivateGracePeriod("k")
+	deadline := time.Now().Add(600 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		time.Sleep(10 * time.Millisecond)
+		if _, ok := c.Get("k"); !ok {
+			return
+		}
+	}
+	t.Fatal("stale entry still served 600ms after a 100ms max grace")
+}
+
+func TestSetMaxSizeNegativeTerminates(t *testing.T) {
+	c := newBoundsCache(t, UniversalCacheConfig{Type: CacheTypeGeneral, MaxSize: 10})
+	for _, k := range []string{"a", "b", "c"} {
+		_ = c.Set(k, "v", time.Hour)
+	}
+	done := make(chan struct{})
+	go func() { c.SetMaxSize(-1); close(done) }()
+	select {
+	case <-done:
+	case <-time.After(2 * time.Second):
+		t.Fatal("SetMaxSize(-1) did not return")
+	}
+}
+
+// One oversized value must not flush the other live entries.
+func TestOversizedValueDoesNotFlushCache(t *testing.T) {
+	c := newBoundsCache(t, UniversalCacheConfig{
+		Type: CacheTypeGeneral, MaxSize: 10, MaxMemoryBytes: 1000, EnableMemoryLimit: true,
+	})
+	_ = c.Set("live", "x", time.Hour)
+	_ = c.Set("big", make([]byte, 5000), time.Hour)
+	if _, ok := c.Get("live"); !ok {
+		t.Fatal("oversized insert evicted a live entry")
+	}
+	c.mu.RLock()
+	mem := c.currentMemory
+	c.mu.RUnlock()
+	if mem > 1000 {
+		t.Fatalf("currentMemory=%d exceeds cap 1000", mem)
+	}
+}
+
+// Out-of-range or non-finite nbf/iat must be rejected, not wrapped into the past.
+func TestTimeClaimsRejectOutOfRange(t *testing.T) {
+	for _, v := range []float64{1e19, 1e300, math.Inf(1), math.Inf(-1), math.NaN()} {
+		if verifyNotBefore(v) == nil {
+			t.Errorf("nbf=%v accepted", v)
+		}
+		if verifyIssuedAt(v) == nil {
+			t.Errorf("iat=%v accepted", v)
+		}
+		if verifyExpiration(v) == nil {
+			t.Errorf("exp=%v accepted", v)
+		}
+	}
+}

url_helpers.go

@@ -453,6 +453,15 @@ func sameHost(a, b string) bool {
 	return strings.EqualFold(ua.Host, ub.Host)
 }
 
+// canonicalHost drops the root dot ("localhost." is localhost) and an IPv6
+// zone id so the blocklists see one spelling per host.
+func canonicalHost(host string) string {
+	if i := strings.IndexByte(host, '%'); i > 0 && net.ParseIP(host[:i]) != nil {
+		host = host[:i]
+	}
+	return strings.TrimRight(host, ".")
+}
+
 // validateHost validates a hostname or IP address for security.
 // It prevents access to localhost, private networks, and known metadata endpoints.
 // When allowPrivateIPAddresses is enabled, private IP checks are skipped.
@@ -462,13 +471,14 @@ func sameHost(a, b string) bool {
 // Returns:
 //   - An error if the host is dangerous or not allowed, nil if safe.
 func (t *TraefikOidc) validateHost(host string) error {
-	hostname := host
-	if strings.Contains(host, ":") {
+	hostname := canonicalHost(host)
+	if net.ParseIP(hostname) == nil && strings.Contains(hostname, ":") {
 		var err error
-		hostname, _, err = net.SplitHostPort(host)
+		hostname, _, err = net.SplitHostPort(hostname)
 		if err != nil {
 			return fmt.Errorf("invalid host format: %w", err)
 		}
+		hostname = canonicalHost(hostname)
 	}
 
 	ip := net.ParseIP(hostname)

version.go

@@ -14,4 +14,4 @@ const devPluginVersion = "0.0.0-dev"
 // from build info at runtime (debug.ReadBuildInfo sees Traefik's build graph,
 // not the interpreted plugin). This build-stamped constant is therefore the
 // single source of truth for the version reported by anonymous usage telemetry.
-const traefikoidcPluginVersion = "0.0.0-dev"
+const traefikoidcPluginVersion = "1.0.62"