feat: opt-in M2M bearer-token authentication (supersedes #93) (#140)

* docs: bearer-token auth design spec

* docs: harden bearer-auth spec with security review findings

* feat(bearer): opt-in M2M bearer-token authentication

Adds an opt-in Authorization: Bearer <jwt> path for machine-to-machine
clients. Replaces and supersedes the broken approach in PR #93
(synthetic-session that omitted user_identifier and skipped ID-token
rejection / replay-protection-semantics / kid-pinning / etc.).

Design

  Two auth entrypoints feed one shared post-auth pipeline:

    cookie path  ─┐
                  ├── forwardAuthorized(rw, req, *principal)
    bearer path  ─┘    (roles/groups, header injection, security
                        headers, cookie strip, forward)

  buildPrincipalFromSession and buildPrincipalFromBearerToken produce
  the same `principal` value type. forwardAuthorized is session-agnostic
  and runs the existing post-auth work; processAuthorizedRequest now
  wraps it with the session-specific concerns (backchannel-logout,
  dirty/Save). The cookie path's behaviour is byte-identical to before
  this PR; the existing test suite passes unmodified.

Security hardening baked into the bearer path

  - Audience MANDATORY. Startup fails when EnableBearerAuth=true and
    Audience is empty.
  - BearerIdentifierClaim defaults to "sub"; "email" is rejected at
    startup to avoid the unverified-email spoofing footgun. Cookie
    path's UserIdentifierClaim is unaffected and still defaults to
    "email".
  - ID tokens explicitly rejected via the existing detectTokenType
    helper (nonce, typ=at+jwt, token_use, scope, aud-vs-clientID
    heuristics); belt-and-braces nonce/token_use=id rejection on top.
  - alg pinned to asymmetric allowlist (RS/PS/ES 256/384/512) BEFORE
    JWKS fetch, blocking alg=none and alg=HS* probes from amplifying
    into upstream calls.
  - kid length capped at 256 bytes and charset-restricted before JWKS
    fetch, blocking pathological-kid JWKS amplification.
  - Multi-audience tokens require azp == clientID.
  - iat upper-age bound (MaxTokenAgeSeconds, default 24h) bounds clock-
    manipulation and forever-token abuse.
  - Identifier sanitization: length cap, control-char + bidi-override
    + delimiter (, ; =) rejection.
  - Per-IP failure throttle: configurable threshold/window/penalty;
    returns 429 + Retry-After. Limits offline-guessing-style attacks
    and protects the shared rate-limiter / JWKS endpoint.
  - JTI replay marking suppressed via new internal verifyOpts
    {skipReplayMarking} so the same bearer can be reused until exp;
    the blacklist Get stays active so RevokeToken still terminates a
    bearer token immediately. The existing exported VerifyToken
    interface is unchanged so all mocks continue to work.
  - Cookie wins by default when both bearer and cookie are present
    (safer against browser/extension/proxy bearer injection).
    Operator can flip via BearerOverridesCookie.
  - Authorization header stripped on forward by default; also stripped
    on excluded URLs so the token can't leak into health/metrics
    downstream logs.
  - Optional RFC 7662 introspection via existing
    requireTokenIntrospection. Introspection-endpoint failure returns
    503 (distinguishes infra from token rejection).
  - 401s use RFC 6750 WWW-Authenticate hints (toggleable). Failure
    reason is logged at debug; raw tokens are never logged.

Implementation

  - principal.go: pure-data principal type and buildPrincipalFromSession.
  - bearer_auth.go: alg/kid pin, classifier, identifier sanitization,
    multi-aud azp gate, iat age check, per-IP failure tracker,
    handleBearerRequest, buildPrincipalFromBearerToken.
  - token_manager.go: VerifyToken now wraps a new verifyTokenWithOpts
    that accepts internal-only verifyOpts. Existing callers, the
    TokenVerifier interface, and all mocks unchanged.
  - middleware.go: extracted forwardAuthorized from
    processAuthorizedRequest; wired bearer detection after init wait
    + after bypass; excluded-URL Authorization strip when bearer
    enabled.
  - settings.go: ten new config fields with defaults applied in
    CreateConfig.
  - main.go: startup validation for audience + identifier-claim
    guard; bearer failure tracker init.

Tests

  - bearer_auth_test.go: table-driven helper tests for every new
    component (parseBearerJOSEHeader, sanitizeBearerIdentifier,
    resolveBearerIdentifier, enforceMultiAudienceAzp, enforceIatAge,
    bearerFailureTracker, detectBearerToken). Integration tests
    through ServeHTTP covering happy path, ID-token rejection,
    alg=none rejection, oversized kid, multi-aud with/without azp,
    iat-too-old, bidi identifier, replay (100x reuse), 429 throttle
    trip, excluded-URL strip, roles gate, cookie-wins precedence,
    BearerOverridesCookie, oversized token, malformed JWT,
    feature-off pass-through. Startup validation for audience-
    required and email-identifier-rejected.
  - All existing tests pass unmodified (cookie-path regression).
  - go vet clean. golangci-lint clean (0 issues). Race detector
    clean on bearer tests.

Documentation

  - README.md: bearer auth section with security highlights and
    config snippet; doc link in the index.
  - .traefik.yml: commented config block exposing every bearer knob.
  - docs/CONFIGURATION.md: new subsection with full parameter table.
  - docs/BEARER_AUTH.md: threat model, hardening matrix, failure
    response table, operational guidance, known follow-ups.
  - docs/superpowers/specs/2026-05-18-bearer-token-auth-design.md:
    design spec + security-review hardening history.

* fix(cache): redact raw cache keys in debug logs (CodeQL go/clear-text-logging)

CodeQL flagged 9 high-severity alerts (go/clear-text-logging) where the
in-memory cache and the hybrid L1+L2 backend printed `key=%s` at debug.
Cache callers (token cache, blacklist, introspection cache) pass raw
access / refresh / id tokens as cache keys, so any debug-enabled
deployment would write them to log streams.

Pre-existing issue. CodeQL started flagging it on this PR because the
new bearer-auth path adds a data-flow source (req.Header.Get("Authorization"))
that reaches the existing logging sinks via the same cache. The cookie
path had the same risk but wasn't tracked as taint by CodeQL.

Fix: hash the key (SHA-256[:8] hex) before printing. Same approach the
bearer-auth logger uses for principal identifiers (spec §13). Doesn't
change cache semantics — same key still produces the same hash, so
debug correlation across log lines is preserved without exposing the
raw value.

Touches both affected packages:
  - internal/cache/cache.go (2 sites: Set + LRU eviction)
  - internal/cache/backends/hybrid.go (12 sites: L1/L2 read/write/fallback)

New helper `redactKey` colocated with each package (unexported,
package-local) keeps the change blast radius narrow. Tests green; lint
clean.

* docs(bearer): how to obtain bearer tokens from the OIDC provider

Adds a section walking operators through the OAuth 2.0 client_credentials
flow (RFC 6749 §4.4) and the JWT bearer assertion alternative (RFC 7523),
with a worked Auth0-shape curl example, a per-provider quick reference
(Auth0, Okta, Keycloak, Entra v2, Cognito, GitLab, Google), operational
notes (token TTL, caching, JWKS rotation, revocation, scope vs audience,
secret hygiene), and a three-line validation loop.

Most common operator confusion: "I enabled the feature but tokens get
401'd" — almost always missing or wrong audience. The new section makes
the audience-matching requirement loud, with per-provider parameter
names so people don't have to dig through IdP docs.

Locations:
  - docs/BEARER_AUTH.md  — full section under "Quick start"
  - README.md            — short snippet + deep link
This commit is contained in:
2026-05-18 17:35:37 +01:00
committed by GitHub
parent 8c5df82dcf
commit a548665edb
17 changed files with 2702 additions and 107 deletions
+22
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@@ -80,3 +80,25 @@ testData:
# address: redis:6379
# password: urn:k8s:secret:redis:password
# cacheMode: hybrid
# Optional: bearer-token authentication for M2M (machine-to-machine) API
# clients. Default off. When enabled, requests presenting
# "Authorization: Bearer <jwt>" are validated against the configured OIDC
# provider (signature/issuer/audience/exp) and forwarded without creating
# a cookie session. The bearer path REJECTS ID tokens, requires a non-
# default audience, and never trusts the `email` claim as the identifier.
# See docs/BEARER_AUTH.md for the full threat model.
#
# enableBearerAuth: true # opt-in
# audience: https://api.example.com # REQUIRED when bearer is enabled
# bearerIdentifierClaim: sub # default; used as X-Forwarded-User. `email` is rejected.
# stripAuthorizationHeader: true # default; drops the raw token before forwarding
# bearerEmitWWWAuthenticate: true # default; RFC 6750 hint on 401s
# bearerOverridesCookie: false # default; cookie wins when both are present
# requireTokenIntrospection: false # opt-in; calls RFC 7662 introspection per request
# maxTokenAgeSeconds: 86400 # 24h cap on iat (rejects clock-skew/forever tokens)
# maxIdentifierLength: 256 # cap on the sanitised principal identifier
# bearerFailureThreshold: 20 # consecutive 401s/IP that trip the throttle
# bearerFailureWindowSeconds: 60 # rolling window over which 401s are counted
# bearerFailurePenaltySeconds: 60 # 429 + Retry-After duration after threshold trips
+87
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@@ -9,6 +9,7 @@ manages sessions, and forwards user identity to downstream services.
- [Configuration reference](docs/CONFIGURATION.md) — every parameter
- [Provider guide](docs/PROVIDERS.md) — Google, Azure, Auth0, Okta, Keycloak, Cognito, GitLab, GitHub, generic
- [Auth0 audience guide](docs/AUTH0_AUDIENCE_GUIDE.md) — custom APIs, opaque tokens, token confusion
- [Bearer-token (M2M) auth](docs/BEARER_AUTH.md) — opt-in `Authorization: Bearer` path, threat model
- [Redis cache](docs/REDIS.md) — multi-replica deployments
- [Dynamic Client Registration](docs/DCR.md) — RFC 7591
- [Development](docs/DEVELOPMENT.md) · [Testing](docs/TESTING.md)
@@ -171,6 +172,92 @@ Each instance must use a unique `cookiePrefix` **and** `sessionEncryptionKey`,
otherwise a session minted by one instance can grant access through another.
See [issue #87](https://github.com/lukaszraczylo/traefikoidc/issues/87).
### Bearer-token (M2M) authentication
Opt-in path for API clients that present `Authorization: Bearer <jwt>` instead
of logging in via the browser flow. Default off. When enabled, the middleware
validates the bearer JWT against the configured OIDC provider (signature,
issuer, audience, expiry) and forwards the request downstream with the
principal headers — no cookie session is created.
```yaml
enableBearerAuth: true
audience: https://api.example.com # REQUIRED when bearer is enabled
# optional, defaults shown:
bearerIdentifierClaim: sub # claim used as X-Forwarded-User
stripAuthorizationHeader: true # drop the raw token before forwarding
bearerEmitWWWAuthenticate: true # RFC 6750 hint on 401s
bearerOverridesCookie: false # cookie wins when both are present (safer)
maxTokenAgeSeconds: 86400 # 24h cap on iat
bearerFailureThreshold: 20 # consecutive 401s/IP before 429 throttle
```
Hardening built in by default:
- **Audience required.** Startup fails if `enableBearerAuth=true` and
`audience` is unset. Eliminates the "token issued for service B accepted
by A" confusion vector.
- **ID tokens explicitly rejected.** Bearer is access-token-only. ID tokens
(detected via `nonce`, `typ: at+jwt`, `token_use`, `scope`, or audience
shape) return `401`.
- **`alg` and `kid` pinned at the entrypoint.** Asymmetric-only allowlist
(`RS256/384/512`, `PS256/384/512`, `ES256/384/512`); `kid` length and
charset capped — both checked **before** any JWKS fetch so attacker noise
can't amplify into upstream calls.
- **Identifier sanitised.** Default identifier source is `sub`; `email` is
rejected unless explicitly opted in (which the middleware still refuses to
avoid the unverified-email spoofing footgun). Control characters, bidi-
override codepoints, and the delimiters `, ; =` are all rejected before
the value reaches `X-Forwarded-User`.
- **Multi-audience tokens require `azp`.** When `aud` is an array of more
than one element, the token must carry `azp == clientID`.
- **`iat` upper-age bound.** Tokens older than `maxTokenAgeSeconds` are
rejected even if `exp` is far in the future.
- **Per-IP 401 throttle.** After `bearerFailureThreshold` consecutive 401s
from one source IP, further bearer requests from that IP are rejected
with `429 Too Many Requests` + `Retry-After`.
- **Cookie-wins by default.** When both a session cookie and an
`Authorization: Bearer` header arrive on the same request, the cookie path
runs (safer against browser/extension/proxy bearer injection). Set
`bearerOverridesCookie: true` for the AWS/GCP/Kubernetes convention.
- **Replay protection preserved.** The bearer path skips the JTI **Set**
(so the same token can be reused) but the **Get** stays active —
`RevokeToken` still terminates a bearer token immediately.
- **Excluded URLs strip Authorization.** When `enableBearerAuth=true`,
excluded paths (e.g. `/health`, `/metrics`) get the `Authorization` header
removed before forwarding so the token can't leak into public endpoint
logs.
- **Optional real-time revocation.** Set `requireTokenIntrospection: true`
to call RFC 7662 introspection on every cache miss; revoked tokens fail
immediately. Introspection endpoint failures return `503` (distinguishes
infra outage from credential rejection).
**Obtaining bearer tokens** — minting is the IdP's job, not the
middleware's. The canonical M2M flow is OAuth 2.0 `client_credentials`
(RFC 6749 §4.4); Google requires JWT bearer assertion (RFC 7523) instead.
Minimal Auth0-shape request:
```bash
curl -s -X POST https://issuer.example.com/oauth/token \
-H 'Content-Type: application/json' \
-d '{
"grant_type": "client_credentials",
"client_id": "your-m2m-client-id",
"client_secret": "your-m2m-client-secret",
"audience": "https://api.example.com",
"scope": "api:read api:write"
}'
```
The `audience` you request from the IdP **must match** the `audience` you
configured on the middleware. Per-provider endpoints, parameter names, and
gotchas (Entra v2 endpoint, Cognito Resource Servers, Keycloak audience
mappers, Google's opaque-token quirk) are documented in
[docs/BEARER_AUTH.md](docs/BEARER_AUTH.md#obtaining-bearer-tokens-from-your-oidc-provider).
Full threat model, configuration matrix, and follow-up gaps in
[docs/BEARER_AUTH.md](docs/BEARER_AUTH.md).
### SSE and WebSocket endpoints
Browser clients cannot follow an OIDC `302` redirect on an SSE stream or a
+592
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@@ -0,0 +1,592 @@
// Package traefikoidc — bearer-token (M2M) authentication path.
//
// Disabled by default. When enabled via Config.EnableBearerAuth, requests
// presenting "Authorization: Bearer <jwt>" are validated against the
// configured OIDC provider (signature, issuer, audience, exp, replay-Get)
// and the request is forwarded downstream without creating a cookie session.
//
// Design rules (kept here in code as the single source of truth):
// - Access tokens only. ID tokens are rejected via detectTokenType.
// - Audience is mandatory (enforced at startup in main.go).
// - alg + kid pinned BEFORE JWKS fetch to deny amplification probes.
// - iat upper-age cap bounds clock-skew / forever-token abuse.
// - Multi-audience tokens require matching azp.
// - Per-IP 401 throttle returns 429 + Retry-After after a threshold.
// - JTI Set is suppressed (skipReplayMarking) but JTI Get stays — revoked
// tokens (RevokeToken adds to blacklist) are still rejected.
// - Identifier is read from BearerIdentifierClaim (default "sub"), never
// from UserIdentifierClaim, to avoid the unverified-email spoofing path.
// - Identifier is sanitized: length cap, control chars, bidi-override,
// delimiter chars (, ; =) rejected.
// - On excluded URLs the Authorization header is stripped before forwarding.
//
// See docs/superpowers/specs/2026-05-18-bearer-token-auth-design.md and
// docs/BEARER_AUTH.md for the full threat model.
package traefikoidc
import (
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"encoding/json"
"fmt"
"net"
"net/http"
"strings"
"sync"
"time"
"unicode"
)
const bearerPrefix = "Bearer "
// bearerAlgAllowlist is the set of JWS algorithms accepted on the bearer
// path. Asymmetric-only — HS* would allow public-key-as-HMAC-secret attacks
// if any operator ever rotates a key into the symmetric branch by mistake;
// "none" is obvious. Matches the allowlist enforced inside jwt.Verify but is
// checked here BEFORE the JWKS fetch so attacker noise can't amplify.
var bearerAlgAllowlist = map[string]struct{}{
"RS256": {}, "RS384": {}, "RS512": {},
"PS256": {}, "PS384": {}, "PS512": {},
"ES256": {}, "ES384": {}, "ES512": {},
}
// bearerKidMaxLen caps the JOSE kid header length to keep memory and cache-key
// usage bounded against attacker-controlled values.
const bearerKidMaxLen = 256
// validKidChar is the allowlist for kid header characters. Letters, digits,
// dot, underscore, hyphen, equals. Intentionally narrow; real-world kid
// values are short URL-safe-base64-ish identifiers.
func validKidChar(r rune) bool {
if r >= 'a' && r <= 'z' {
return true
}
if r >= 'A' && r <= 'Z' {
return true
}
if r >= '0' && r <= '9' {
return true
}
switch r {
case '.', '_', '-', '=':
return true
}
return false
}
// bearerError categorizes failure modes for the response builder. Categories
// map 1:1 to the table in docs/superpowers/specs/2026-05-18-bearer-token-auth-design.md
// §9 so behavior is auditable from spec to code.
type bearerErrorKind int
const (
bearerErrInvalidRequest bearerErrorKind = iota
bearerErrInvalidToken
bearerErrTokenInactive
bearerErrInvalidIdentifier
bearerErrForbidden
bearerErrThrottled
bearerErrIntrospectionUnavailable
)
type bearerError struct {
kind bearerErrorKind
reason string
}
func (e *bearerError) Error() string { return e.reason }
func newBearerError(kind bearerErrorKind, reason string) *bearerError {
return &bearerError{kind: kind, reason: reason}
}
// joseHeader is the minimal subset of the JWS protected header we inspect
// BEFORE running the full verification pipeline. Lifted out so the alg+kid
// pin can run without paying for parseJWT's full claim decode.
type joseHeader struct {
Alg string `json:"alg"`
Kid string `json:"kid"`
Typ string `json:"typ"`
}
// parseBearerJOSEHeader decodes the first JWT segment for early alg/kid pinning.
// Does not touch the payload or signature — those are the verifier's job.
// Returns nil on success; *bearerError on rejection so the handler can map
// directly to a status code. The decoded header itself is not surfaced because
// callers don't need it (verifyTokenWithOpts re-parses internally).
func parseBearerJOSEHeader(token string) *bearerError {
dot := strings.IndexByte(token, '.')
if dot <= 0 {
return newBearerError(bearerErrInvalidToken, "malformed JWT: no header segment")
}
raw, err := base64.RawURLEncoding.DecodeString(token[:dot])
if err != nil {
// Some IdPs pad with '='; tolerate by retrying with StdEncoding.
raw, err = base64.URLEncoding.DecodeString(token[:dot])
if err != nil {
return newBearerError(bearerErrInvalidToken, "malformed JWT: header not base64url")
}
}
var hdr joseHeader
if err := json.Unmarshal(raw, &hdr); err != nil {
return newBearerError(bearerErrInvalidToken, "malformed JWT: header not JSON")
}
if _, ok := bearerAlgAllowlist[hdr.Alg]; !ok {
return newBearerError(bearerErrInvalidToken, fmt.Sprintf("disallowed alg %q on bearer path", hdr.Alg))
}
if hdr.Kid == "" {
return newBearerError(bearerErrInvalidToken, "missing kid header")
}
if len(hdr.Kid) > bearerKidMaxLen {
return newBearerError(bearerErrInvalidToken, "kid header exceeds max length")
}
for _, r := range hdr.Kid {
if !validKidChar(r) {
return newBearerError(bearerErrInvalidToken, "kid header contains disallowed characters")
}
}
return nil
}
// sanitizeBearerIdentifier validates and trims a principal identifier before
// it is injected into request headers. Layered defense: net/http will reject
// CRLF on the wire too, but rejecting early gives clearer error logs and
// prevents bidi-override / delimiter chars that pass net/http's narrower
// checks but confuse downstream parsers and admin UIs.
func sanitizeBearerIdentifier(raw string, maxLen int) (string, *bearerError) {
identifier := strings.TrimSpace(raw)
if identifier == "" {
return "", newBearerError(bearerErrInvalidIdentifier, "identifier claim empty")
}
if maxLen > 0 && len(identifier) > maxLen {
return "", newBearerError(bearerErrInvalidIdentifier, "identifier exceeds max length")
}
for _, r := range identifier {
if unicode.IsControl(r) {
return "", newBearerError(bearerErrInvalidIdentifier, "identifier contains control character")
}
// Unicode bidi-override range (RTL spoofing of admin UI / SIEM).
if (r >= 0x202A && r <= 0x202E) || (r >= 0x2066 && r <= 0x2069) {
return "", newBearerError(bearerErrInvalidIdentifier, "identifier contains bidi-override character")
}
if r == ',' || r == ';' || r == '=' {
return "", newBearerError(bearerErrInvalidIdentifier, "identifier contains delimiter character")
}
}
return identifier, nil
}
// resolveBearerIdentifier picks the principal identifier from claims using
// the configured BearerIdentifierClaim (default "sub"). Decoupled from
// userIdentifierClaim (cookie path) to avoid the unverified-email spoofing
// vector documented in the spec §13.
func resolveBearerIdentifier(claims map[string]interface{}, claimName string) (string, *bearerError) {
if claimName == "" {
claimName = "sub"
}
raw, ok := claims[claimName]
if !ok {
return "", newBearerError(bearerErrInvalidIdentifier, fmt.Sprintf("missing claim %q", claimName))
}
str, ok := raw.(string)
if !ok {
return "", newBearerError(bearerErrInvalidIdentifier, fmt.Sprintf("claim %q not a string", claimName))
}
return str, nil
}
// enforceMultiAudienceAzp implements the spec hardening: when aud is a
// multi-element array, require an azp claim equal to clientID. Single-string
// aud is unaffected (existing verifyAudience handles it).
func enforceMultiAudienceAzp(claims map[string]interface{}, clientID string) *bearerError {
audRaw, ok := claims["aud"]
if !ok {
return nil // verifyToken already rejects missing aud
}
arr, ok := audRaw.([]interface{})
if !ok {
return nil // single-string aud
}
if len(arr) <= 1 {
return nil
}
azpRaw, ok := claims["azp"]
if !ok {
return newBearerError(bearerErrInvalidToken, "multi-audience token missing azp")
}
azp, ok := azpRaw.(string)
if !ok || azp == "" {
return newBearerError(bearerErrInvalidToken, "multi-audience token has empty/non-string azp")
}
if azp != clientID {
return newBearerError(bearerErrInvalidToken, "multi-audience token azp does not match clientID")
}
return nil
}
// enforceIatAge implements the spec MaxTokenAgeSeconds bound on iat. Bounds
// clock-manipulation / forever-token abuse without rejecting tokens with a
// normal iat just because the issuer's clock skews a few seconds.
func enforceIatAge(claims map[string]interface{}, maxAge time.Duration) *bearerError {
if maxAge <= 0 {
return nil
}
iatRaw, ok := claims["iat"].(float64)
if !ok {
// jwt.Verify already requires iat; this branch shouldn't be reached.
return newBearerError(bearerErrInvalidToken, "missing iat claim")
}
iat := time.Unix(int64(iatRaw), 0)
if time.Since(iat) > maxAge {
return newBearerError(bearerErrInvalidToken, "token iat outside age bound")
}
return nil
}
// hashIdentifierForLog returns a short SHA-256 prefix safe for info-level
// logs. Full identifier is only emitted at debug. Satisfies the audit
// requirement (trace which principal was rejected) without leaking PII.
func hashIdentifierForLog(identifier string) string {
if identifier == "" {
return "(none)"
}
sum := sha256.Sum256([]byte(identifier))
return hex.EncodeToString(sum[:4]) // 8 hex chars
}
// --- Per-IP failure throttle ---
// bearerFailureTracker records consecutive bearer-auth 401s per source IP and
// parks repeat offenders in a 429 penalty box. Limits offline-guessing-style
// attacks and protects the shared rate-limiter / JWKS endpoint from being
// burned by a single source.
type bearerFailureTracker struct {
mu sync.Mutex
entries map[string]*bearerFailureEntry
// Configuration snapshot. Captured at construction so a hot reconfigure
// doesn't race with the per-request paths.
threshold int
window time.Duration
penalty time.Duration
}
type bearerFailureEntry struct {
firstFailureAt time.Time
penaltyUntil time.Time
count int
}
func newBearerFailureTracker(threshold int, window, penalty time.Duration) *bearerFailureTracker {
if threshold <= 0 {
threshold = 20
}
if window <= 0 {
window = 60 * time.Second
}
if penalty <= 0 {
penalty = 60 * time.Second
}
return &bearerFailureTracker{
entries: make(map[string]*bearerFailureEntry),
threshold: threshold,
window: window,
penalty: penalty,
}
}
// blocked reports whether the source IP is currently in the penalty box.
// Returns (true, retryAfter) when blocked; (false, 0) when allowed.
func (b *bearerFailureTracker) blocked(ip string) (bool, time.Duration) {
if b == nil || ip == "" {
return false, 0
}
b.mu.Lock()
defer b.mu.Unlock()
e, ok := b.entries[ip]
if !ok {
return false, 0
}
now := time.Now()
if !e.penaltyUntil.IsZero() && now.Before(e.penaltyUntil) {
return true, time.Until(e.penaltyUntil)
}
return false, 0
}
// recordFailure increments the failure counter for the given IP and trips
// the penalty box once threshold-within-window is exceeded.
func (b *bearerFailureTracker) recordFailure(ip string) {
if b == nil || ip == "" {
return
}
b.mu.Lock()
defer b.mu.Unlock()
now := time.Now()
e, ok := b.entries[ip]
if !ok || now.Sub(e.firstFailureAt) > b.window {
e = &bearerFailureEntry{firstFailureAt: now}
b.entries[ip] = e
}
e.count++
if e.count >= b.threshold {
e.penaltyUntil = now.Add(b.penalty)
}
}
// recordSuccess clears the failure counter for the given IP after a
// successful bearer auth.
func (b *bearerFailureTracker) recordSuccess(ip string) {
if b == nil || ip == "" {
return
}
b.mu.Lock()
defer b.mu.Unlock()
delete(b.entries, ip)
}
// clientIPForBearer returns the source IP used to key the failure tracker.
// Trusts only the request's transport-level RemoteAddr; X-Forwarded-For is
// intentionally ignored to avoid attacker-controlled key spoofing. Behind a
// trusted reverse proxy where every request shares one IP, the throttle is
// still useful (caps attacker churn through that proxy) — operators wanting
// per-real-client throttling must terminate at this middleware.
func clientIPForBearer(req *http.Request) string {
if req == nil {
return ""
}
host, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
return req.RemoteAddr
}
return host
}
// --- Bearer auth entrypoint ---
// detectBearerToken returns (token, true) when the request carries a usable
// Authorization: Bearer header. Case-insensitive on the scheme. Returns
// ("", false) for any other shape.
func detectBearerToken(req *http.Request) (string, bool) {
if req == nil {
return "", false
}
h := req.Header.Get("Authorization")
if len(h) < len(bearerPrefix) {
return "", false
}
if !strings.EqualFold(h[:len(bearerPrefix)], bearerPrefix) {
return "", false
}
token := strings.TrimSpace(h[len(bearerPrefix):])
if token == "" {
return "", false
}
return token, true
}
// hasSessionCookie reports whether the request carries any cookie matching
// the session prefix. Used to implement the cookie-wins-by-default
// precedence rule when both bearer and cookie are present.
func (t *TraefikOidc) hasSessionCookie(req *http.Request) bool {
if t.sessionManager == nil {
return false
}
prefix := t.sessionManager.GetCookiePrefix()
if prefix == "" {
return false
}
for _, c := range req.Cookies() {
if strings.HasPrefix(c.Name, prefix) {
return true
}
}
return false
}
// writeBearerError writes the canonical 401/403/429/503 response per spec §9.
// Body is always generic; reason is logged at debug only. The
// WWW-Authenticate hint is gated by config (default on, RFC 6750 compliant).
func (t *TraefikOidc) writeBearerError(rw http.ResponseWriter, req *http.Request, err *bearerError) {
var (
status int
errCode string
body string
retryAfter time.Duration
)
switch err.kind {
case bearerErrInvalidRequest:
status = http.StatusUnauthorized
errCode = "invalid_request"
body = "Unauthorized"
case bearerErrInvalidToken, bearerErrTokenInactive, bearerErrInvalidIdentifier:
status = http.StatusUnauthorized
errCode = "invalid_token"
body = "Unauthorized"
case bearerErrForbidden:
status = http.StatusForbidden
body = "Access denied"
case bearerErrThrottled:
status = http.StatusTooManyRequests
body = "Too Many Requests"
retryAfter = t.bearerFailurePenalty
case bearerErrIntrospectionUnavailable:
status = http.StatusServiceUnavailable
body = "Service Unavailable"
default:
status = http.StatusUnauthorized
body = "Unauthorized"
}
if t.bearerEmitWWWAuthenticate && errCode != "" {
rw.Header().Set("WWW-Authenticate", fmt.Sprintf(`Bearer error=%q`, errCode))
}
if retryAfter > 0 {
rw.Header().Set("Retry-After", fmt.Sprintf("%d", int(retryAfter.Seconds())))
}
rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
rw.WriteHeader(status)
_, _ = rw.Write([]byte(body)) // Safe to ignore: best-effort error body write
if t.logger != nil {
t.logger.Debugf("bearer auth rejected: status=%d category=%v reason=%q path=%s",
status, err.kind, err.reason, req.URL.Path)
}
}
// handleBearerRequest is the entry point invoked by ServeHTTP when the
// EnableBearerAuth flag is set, the request carries an Authorization: Bearer
// header, and the (configurable) cookie-precedence rule allows the bearer
// path to run.
func (t *TraefikOidc) handleBearerRequest(rw http.ResponseWriter, req *http.Request) {
ip := clientIPForBearer(req)
if blocked, retryAfter := t.bearerFailureTracker.blocked(ip); blocked {
throttled := newBearerError(bearerErrThrottled, "ip in penalty box")
// Preserve the actual retry-after even if it diverged from the
// configured default (clock-skew, partial-window expiry).
if retryAfter > 0 {
rw.Header().Set("Retry-After", fmt.Sprintf("%d", int(retryAfter.Seconds())))
}
t.writeBearerError(rw, req, throttled)
return
}
token, ok := detectBearerToken(req)
if !ok {
t.bearerFailureTracker.recordFailure(ip)
t.writeBearerError(rw, req, newBearerError(bearerErrInvalidRequest, "missing or empty bearer token"))
return
}
if len(token) > AccessTokenConfig.MaxLength {
t.bearerFailureTracker.recordFailure(ip)
t.writeBearerError(rw, req, newBearerError(bearerErrInvalidToken, "token exceeds max length"))
return
}
if strings.Count(token, ".") != 2 {
t.bearerFailureTracker.recordFailure(ip)
t.writeBearerError(rw, req, newBearerError(bearerErrInvalidToken, "token is not a 3-segment JWT"))
return
}
if bErr := parseBearerJOSEHeader(token); bErr != nil {
t.bearerFailureTracker.recordFailure(ip)
t.writeBearerError(rw, req, bErr)
return
}
p, bErr := t.buildPrincipalFromBearerToken(token)
if bErr != nil {
t.bearerFailureTracker.recordFailure(ip)
t.writeBearerError(rw, req, bErr)
return
}
t.bearerFailureTracker.recordSuccess(ip)
if t.logger != nil {
t.logger.Debugf("bearer auth success: identifier_hash=%s path=%s",
hashIdentifierForLog(p.Identifier), req.URL.Path)
}
t.forwardAuthorized(rw, req, p)
}
// buildPrincipalFromBearerToken runs the full bearer verification pipeline
// described in spec §7.3 and returns a principal ready for forwardAuthorized.
// Returns a typed *bearerError on failure so the caller can map to status.
func (t *TraefikOidc) buildPrincipalFromBearerToken(token string) (*principal, *bearerError) {
if err := t.verifyTokenWithOpts(token, verifyOpts{skipReplayMarking: true}); err != nil {
return nil, newBearerError(bearerErrInvalidToken, "token verification failed: "+err.Error())
}
parsed, err := parseJWT(token)
if err != nil {
return nil, newBearerError(bearerErrInvalidToken, "post-verify parseJWT failed: "+err.Error())
}
claims := parsed.Claims
// Token-type guard. Reuse the well-tested classifier which already
// checks nonce / typ=at+jwt / token_use / scope / aud-vs-clientID.
if t.detectTokenType(parsed, token) {
return nil, newBearerError(bearerErrInvalidToken, "ID tokens are not accepted on the bearer path")
}
// Belt-and-braces explicit rejection (cheap, catches edge cases not
// covered by detectTokenType's heuristic).
if nonce, ok := claims["nonce"].(string); ok && nonce != "" {
return nil, newBearerError(bearerErrInvalidToken, "nonce claim present (ID-token shape)")
}
if tu, ok := claims["token_use"].(string); ok && tu == "id" {
return nil, newBearerError(bearerErrInvalidToken, "token_use=id rejected")
}
if bErr := enforceMultiAudienceAzp(claims, t.clientID); bErr != nil {
return nil, bErr
}
if bErr := enforceIatAge(claims, t.maxTokenAge); bErr != nil {
return nil, bErr
}
if t.requireTokenIntrospection {
if bErr := t.introspectOnBearerPath(token); bErr != nil {
return nil, bErr
}
}
rawIdentifier, bErr := resolveBearerIdentifier(claims, t.bearerIdentifierClaim)
if bErr != nil {
return nil, bErr
}
identifier, bErr := sanitizeBearerIdentifier(rawIdentifier, t.maxIdentifierLength)
if bErr != nil {
return nil, bErr
}
subject, _ := claims["sub"].(string)
clientID, _ := claims["azp"].(string)
if clientID == "" {
clientID, _ = claims["client_id"].(string)
}
return &principal{
Source: sourceBearer,
Identifier: identifier,
Subject: subject,
ClientID: clientID,
Claims: claims,
AccessToken: token,
}, nil
}
// introspectOnBearerPath calls the existing RFC 7662 introspector when the
// operator demands real-time revocation. Distinguishes "token revoked" (401)
// from "endpoint unavailable" (503) so transient infra failures don't look
// like credential failures.
func (t *TraefikOidc) introspectOnBearerPath(token string) *bearerError {
resp, err := t.introspectToken(token)
if err != nil {
return newBearerError(bearerErrIntrospectionUnavailable, "introspection failed: "+err.Error())
}
if !resp.Active {
return newBearerError(bearerErrTokenInactive, "introspection reports token inactive")
}
return nil
}
+812
View File
@@ -0,0 +1,812 @@
package traefikoidc
import (
"context"
"encoding/base64"
"encoding/json"
"fmt"
"net/http"
"net/http/httptest"
"strings"
"sync/atomic"
"testing"
"time"
"golang.org/x/time/rate"
)
// =============================================================================
// Helper builders
// =============================================================================
// makeBearerJWT constructs a JWT with explicit header + claims for tests.
// Signature is opaque (b64("signature")) — bearer tests don't exercise the
// real cryptographic verifier; verification is bypassed via tokenCache pre-
// seed so the bearer pipeline under test sees a "verified" token.
func makeBearerJWT(t *testing.T, header, claims map[string]interface{}) string {
t.Helper()
hb, err := json.Marshal(header)
if err != nil {
t.Fatalf("marshal header: %v", err)
}
cb, err := json.Marshal(claims)
if err != nil {
t.Fatalf("marshal claims: %v", err)
}
return fmt.Sprintf("%s.%s.%s",
base64.RawURLEncoding.EncodeToString(hb),
base64.RawURLEncoding.EncodeToString(cb),
base64.RawURLEncoding.EncodeToString([]byte("signature")),
)
}
// defaultBearerHeader produces the standard RS256+kid header used in tests.
func defaultBearerHeader() map[string]interface{} {
return map[string]interface{}{"alg": "RS256", "kid": "test-kid"}
}
// defaultBearerClaims produces a baseline access-token claim set. Tests
// shallow-clone and override fields as needed.
func defaultBearerClaims() map[string]interface{} {
return map[string]interface{}{
"iss": "https://issuer.example.com",
"aud": "https://api.example.com",
"sub": "service-account-1",
"scope": "api:read api:write",
"exp": float64(time.Now().Add(time.Hour).Unix()),
"iat": float64(time.Now().Unix()),
}
}
// makeBearerOIDC constructs a TraefikOidc wired for bearer auth tests. The
// real verifyTokenWithOpts pipeline is short-circuited via tokenCache pre-
// seed: any token Set into t.tokenCache returns nil from VerifyToken,
// letting tests exercise the post-verify bearer logic (classifier, identifier,
// throttle, header forwarding) without standing up JWKs.
func makeBearerOIDC(t *testing.T, next http.Handler) *TraefikOidc {
t.Helper()
sm := createTestSessionManager(t)
oidc := &TraefikOidc{
next: next,
logger: NewLogger("error"),
initComplete: make(chan struct{}),
sessionManager: sm,
firstRequestReceived: true,
metadataRefreshStarted: true,
issuerURL: "https://issuer.example.com",
audience: "https://api.example.com",
clientID: "https://api.example.com",
tokenCache: NewTokenCache(),
excludedURLs: map[string]struct{}{"/favicon.ico": {}},
allowedRolesAndGroups: map[string]struct{}{},
limiter: rate.NewLimiter(rate.Every(time.Second), 1000),
ctx: context.Background(),
enableBearerAuth: true,
stripAuthorizationHeader: true,
bearerEmitWWWAuthenticate: true,
bearerOverridesCookie: false,
bearerIdentifierClaim: "sub",
maxIdentifierLength: 256,
maxTokenAge: 24 * time.Hour,
bearerFailureThreshold: 20,
bearerFailureWindow: 60 * time.Second,
bearerFailurePenalty: 60 * time.Second,
bearerFailureTracker: newBearerFailureTracker(20, 60*time.Second, 60*time.Second),
}
oidc.extractClaimsFunc = extractClaims
close(oidc.initComplete)
return oidc
}
// seedVerified pre-populates the tokenCache so verifyTokenWithOpts short-
// circuits to nil for the given token. Mirrors the production fast-return
// path at token_manager.go for previously-verified tokens.
func seedVerified(t *testing.T, oidc *TraefikOidc, token string, claims map[string]interface{}) {
t.Helper()
if oidc.tokenCache == nil {
oidc.tokenCache = NewTokenCache()
}
oidc.tokenCache.Set(token, claims, time.Hour)
}
// =============================================================================
// Unit tests — small helpers
// =============================================================================
func TestDetectBearerToken(t *testing.T) {
t.Parallel()
cases := []struct {
name string
header string
want string
ok bool
}{
{"missing header", "", "", false},
{"basic auth", "Basic abc", "", false},
{"bearer with token", "Bearer abc.def.ghi", "abc.def.ghi", true},
{"lowercase bearer", "bearer abc.def.ghi", "abc.def.ghi", true},
{"mixed case", "BeArEr abc.def.ghi", "abc.def.ghi", true},
{"empty token after prefix", "Bearer ", "", false},
{"bearer no space", "Bearerabc", "", false},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
req := httptest.NewRequest("GET", "/", nil)
if tc.header != "" {
req.Header.Set("Authorization", tc.header)
}
got, ok := detectBearerToken(req)
if ok != tc.ok || got != tc.want {
t.Fatalf("got=(%q, %v), want=(%q, %v)", got, ok, tc.want, tc.ok)
}
})
}
}
func TestParseBearerJOSEHeader(t *testing.T) {
t.Parallel()
mk := func(t *testing.T, h map[string]interface{}) string {
return makeBearerJWT(t, h, map[string]interface{}{"sub": "x"})
}
cases := []struct {
header map[string]interface{}
name string
wantErr bool
}{
{name: "valid RS256", header: map[string]interface{}{"alg": "RS256", "kid": "k1"}, wantErr: false},
{name: "valid ES512", header: map[string]interface{}{"alg": "ES512", "kid": "abc-_.="}, wantErr: false},
{name: "alg=none rejected", header: map[string]interface{}{"alg": "none", "kid": "k1"}, wantErr: true},
{name: "alg=HS256 rejected", header: map[string]interface{}{"alg": "HS256", "kid": "k1"}, wantErr: true},
{name: "missing kid", header: map[string]interface{}{"alg": "RS256"}, wantErr: true},
{name: "kid too long", header: map[string]interface{}{"alg": "RS256", "kid": strings.Repeat("a", bearerKidMaxLen+1)}, wantErr: true},
{name: "kid bad chars", header: map[string]interface{}{"alg": "RS256", "kid": "evil/../etc/passwd"}, wantErr: true},
{name: "kid with space", header: map[string]interface{}{"alg": "RS256", "kid": "key one"}, wantErr: true},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
token := mk(t, tc.header)
err := parseBearerJOSEHeader(token)
if (err != nil) != tc.wantErr {
t.Fatalf("err=%v wantErr=%v", err, tc.wantErr)
}
})
}
}
func TestSanitiseBearerIdentifier(t *testing.T) {
t.Parallel()
cases := []struct {
name string
in string
want string
wantErr bool
}{
{"normal sub", "service-account-1", "service-account-1", false},
{"email-like", "alice@example.com", "alice@example.com", false},
{"trim whitespace", " abc ", "abc", false},
{"empty", "", "", true},
{"only whitespace", " ", "", true},
{"control char (newline)", "alice\nbob", "", true},
{"control char (CR)", "alice\rbob", "", true},
{"control char (NUL)", "alice\x00bob", "", true},
{"bidi override", "alice\u202ebob", "", true},
{"bidi isolate", "alice\u2066bob", "", true},
{"comma delimiter", "alice,bob", "", true},
{"semicolon delimiter", "alice;bob", "", true},
{"equals delimiter", "alice=bob", "", true},
{"over length", strings.Repeat("a", 257), "", true},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
got, err := sanitizeBearerIdentifier(tc.in, 256)
if (err != nil) != tc.wantErr {
t.Fatalf("err=%v wantErr=%v", err, tc.wantErr)
}
if !tc.wantErr && got != tc.want {
t.Fatalf("got=%q want=%q", got, tc.want)
}
})
}
}
func TestResolveBearerIdentifier(t *testing.T) {
t.Parallel()
cases := []struct {
claims map[string]interface{}
name string
claim string
want string
wantErr bool
}{
{name: "default sub", claims: map[string]interface{}{"sub": "abc"}, claim: "", want: "abc"},
{name: "explicit sub", claims: map[string]interface{}{"sub": "abc"}, claim: "sub", want: "abc"},
{name: "custom client_id claim", claims: map[string]interface{}{"client_id": "svc"}, claim: "client_id", want: "svc"},
{name: "missing claim", claims: map[string]interface{}{"other": "x"}, claim: "sub", wantErr: true},
{name: "non-string claim", claims: map[string]interface{}{"sub": 123}, claim: "sub", wantErr: true},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
got, err := resolveBearerIdentifier(tc.claims, tc.claim)
if (err != nil) != tc.wantErr {
t.Fatalf("err=%v wantErr=%v", err, tc.wantErr)
}
if !tc.wantErr && got != tc.want {
t.Fatalf("got=%q want=%q", got, tc.want)
}
})
}
}
func TestEnforceMultiAudienceAzp(t *testing.T) {
t.Parallel()
const cid = "https://api.example.com"
cases := []struct {
claims map[string]interface{}
name string
wantErr bool
}{
{name: "single string aud", claims: map[string]interface{}{"aud": "x"}, wantErr: false},
{name: "single element array", claims: map[string]interface{}{"aud": []interface{}{"x"}}, wantErr: false},
{name: "multi-aud with matching azp", claims: map[string]interface{}{"aud": []interface{}{"a", "b"}, "azp": cid}, wantErr: false},
{name: "multi-aud missing azp", claims: map[string]interface{}{"aud": []interface{}{"a", "b"}}, wantErr: true},
{name: "multi-aud empty azp", claims: map[string]interface{}{"aud": []interface{}{"a", "b"}, "azp": ""}, wantErr: true},
{name: "multi-aud wrong azp", claims: map[string]interface{}{"aud": []interface{}{"a", "b"}, "azp": "other"}, wantErr: true},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
err := enforceMultiAudienceAzp(tc.claims, cid)
if (err != nil) != tc.wantErr {
t.Fatalf("err=%v wantErr=%v", err, tc.wantErr)
}
})
}
}
func TestEnforceIatAge(t *testing.T) {
t.Parallel()
now := time.Now()
cases := []struct {
name string
iat float64
maxAge time.Duration
wantErr bool
}{
{name: "fresh", iat: float64(now.Unix()), maxAge: time.Hour, wantErr: false},
{name: "23h59m old, max 24h", iat: float64(now.Add(-23*time.Hour - 59*time.Minute).Unix()), maxAge: 24 * time.Hour, wantErr: false},
{name: "25h old, max 24h", iat: float64(now.Add(-25 * time.Hour).Unix()), maxAge: 24 * time.Hour, wantErr: true},
{name: "1970 token", iat: float64(0), maxAge: 24 * time.Hour, wantErr: true},
{name: "maxAge disabled (0)", iat: float64(0), maxAge: 0, wantErr: false},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
err := enforceIatAge(map[string]interface{}{"iat": tc.iat}, tc.maxAge)
if (err != nil) != tc.wantErr {
t.Fatalf("err=%v wantErr=%v", err, tc.wantErr)
}
})
}
}
func TestBearerFailureTracker(t *testing.T) {
t.Parallel()
tr := newBearerFailureTracker(3, 60*time.Second, 60*time.Second)
const ip = "10.0.0.1"
// Below threshold: not blocked.
for i := 0; i < 2; i++ {
tr.recordFailure(ip)
if b, _ := tr.blocked(ip); b {
t.Fatalf("blocked too early after %d failures", i+1)
}
}
// Threshold reached: blocked.
tr.recordFailure(ip)
if b, retry := tr.blocked(ip); !b || retry <= 0 {
t.Fatalf("expected blocked with positive retry, got=%v retry=%v", b, retry)
}
// Success clears the counter.
tr.recordSuccess(ip)
if b, _ := tr.blocked(ip); b {
t.Fatalf("expected unblocked after success")
}
// Other IPs are unaffected.
if b, _ := tr.blocked("10.0.0.2"); b {
t.Fatalf("unrelated IP should not be blocked")
}
}
// =============================================================================
// Integration tests — full ServeHTTP via the bearer pipeline
// =============================================================================
func TestServeHTTP_Bearer_HappyPath(t *testing.T) {
t.Parallel()
var nextCalled atomic.Bool
var capturedHeaders http.Header
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
nextCalled.Store(true)
capturedHeaders = r.Header.Clone()
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if !nextCalled.Load() {
t.Fatalf("expected next handler to run; got status=%d body=%q", rw.Code, rw.Body.String())
}
if rw.Code != http.StatusOK {
t.Fatalf("status=%d, want 200", rw.Code)
}
if got := capturedHeaders.Get("X-Forwarded-User"); got != "service-account-1" {
t.Fatalf("X-Forwarded-User=%q, want service-account-1", got)
}
if got := capturedHeaders.Get("Authorization"); got != "" {
t.Fatalf("Authorization should be stripped, got=%q", got)
}
}
func TestServeHTTP_Bearer_StripAuthDisabled(t *testing.T) {
t.Parallel()
var capturedAuth string
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
capturedAuth = r.Header.Get("Authorization")
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
oidc.stripAuthorizationHeader = false
claims := defaultBearerClaims()
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if !strings.HasPrefix(capturedAuth, "Bearer ") {
t.Fatalf("expected Authorization to be forwarded, got=%q", capturedAuth)
}
}
func TestServeHTTP_Bearer_RejectIDToken(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for ID token rejection")
})
oidc := makeBearerOIDC(t, next)
// ID-token shape: nonce claim present and no scope. detectTokenType
// returns true.
claims := map[string]interface{}{
"iss": "https://issuer.example.com",
"aud": "https://api.example.com",
"sub": "user-1",
"nonce": "n-0S6_WzA2Mj",
"exp": float64(time.Now().Add(time.Hour).Unix()),
"iat": float64(time.Now().Unix()),
}
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
if wa := rw.Header().Get("WWW-Authenticate"); !strings.Contains(wa, `error="invalid_token"`) {
t.Fatalf("expected WWW-Authenticate invalid_token, got=%q", wa)
}
}
func TestServeHTTP_Bearer_AlgNoneRejected(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for alg=none")
})
oidc := makeBearerOIDC(t, next)
header := map[string]interface{}{"alg": "none", "kid": "k1"}
claims := defaultBearerClaims()
token := makeBearerJWT(t, header, claims)
// Even if we pre-seeded the cache, the early alg pin runs FIRST.
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_KidTooLongRejected(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for oversized kid")
})
oidc := makeBearerOIDC(t, next)
header := map[string]interface{}{"alg": "RS256", "kid": strings.Repeat("a", bearerKidMaxLen+1)}
claims := defaultBearerClaims()
token := makeBearerJWT(t, header, claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_MultiAudRequiresAzp(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for multi-aud without azp")
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
claims["aud"] = []interface{}{"https://api.example.com", "https://other.example.com"}
delete(claims, "azp")
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_MultiAudWithAzpAccepted(t *testing.T) {
t.Parallel()
var nextCalled atomic.Bool
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
nextCalled.Store(true)
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
claims["aud"] = []interface{}{"https://api.example.com", "https://other.example.com"}
claims["azp"] = oidc.clientID
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusOK || !nextCalled.Load() {
t.Fatalf("expected 200 + next called; got status=%d called=%v", rw.Code, nextCalled.Load())
}
}
func TestServeHTTP_Bearer_IatTooOldRejected(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for old iat")
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
claims["iat"] = float64(time.Now().Add(-25 * time.Hour).Unix())
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_IdentifierWithBidiRejected(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for bidi identifier")
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
claims["sub"] = "alice\u202ebob"
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_ReplayRegression(t *testing.T) {
t.Parallel()
var successCount atomic.Int32
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
successCount.Add(1)
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
claims["jti"] = "regression-jti"
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
for i := 0; i < 100; i++ {
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusOK {
t.Fatalf("iteration %d: status=%d, want 200", i, rw.Code)
}
}
if successCount.Load() != 100 {
t.Fatalf("successCount=%d, want 100", successCount.Load())
}
}
func TestServeHTTP_Bearer_ThrottleTrips429(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run during throttle test")
})
oidc := makeBearerOIDC(t, next)
oidc.bearerFailureTracker = newBearerFailureTracker(3, 60*time.Second, 60*time.Second)
// Send malformed bearers from the same RemoteAddr until threshold trips.
send := func() *httptest.ResponseRecorder {
req := httptest.NewRequest("GET", "/api/work", nil)
req.RemoteAddr = "10.0.0.5:1234"
req.Header.Set("Authorization", "Bearer not-a-jwt")
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
return rw
}
for i := 0; i < 3; i++ {
rw := send()
if rw.Code != http.StatusUnauthorized {
t.Fatalf("pre-throttle iteration %d: status=%d, want 401", i, rw.Code)
}
}
// 4th request: throttled.
rw := send()
if rw.Code != http.StatusTooManyRequests {
t.Fatalf("expected 429 after threshold, got %d", rw.Code)
}
if ra := rw.Header().Get("Retry-After"); ra == "" {
t.Fatalf("expected Retry-After header on 429")
}
}
func TestServeHTTP_Bearer_ExcludedURLStripsAuth(t *testing.T) {
t.Parallel()
var capturedAuth string
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
capturedAuth = r.Header.Get("Authorization")
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
oidc.excludedURLs = map[string]struct{}{"/favicon.ico": {}}
req := httptest.NewRequest("GET", "/favicon.ico", nil)
req.Header.Set("Authorization", "Bearer abc.def.ghi")
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusOK {
t.Fatalf("excluded path should pass; got %d", rw.Code)
}
if capturedAuth != "" {
t.Fatalf("Authorization must be stripped on excluded paths, got=%q", capturedAuth)
}
}
func TestServeHTTP_Bearer_RolesGate(t *testing.T) {
t.Parallel()
cases := []struct {
name string
rolesClaim []interface{}
want int
}{
{name: "matching role", rolesClaim: []interface{}{"admin"}, want: http.StatusOK},
{name: "no matching role", rolesClaim: []interface{}{"viewer"}, want: http.StatusForbidden},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
oidc.allowedRolesAndGroups = map[string]struct{}{"admin": {}}
oidc.roleClaimName = "roles"
claims := defaultBearerClaims()
claims["roles"] = tc.rolesClaim
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != tc.want {
t.Fatalf("status=%d, want %d", rw.Code, tc.want)
}
})
}
}
func TestServeHTTP_Bearer_CookieWinsByDefault(t *testing.T) {
t.Parallel()
// Both cookie and bearer present: cookie path runs (which will redirect
// to /authorize since the cookie is empty/unauthenticated).
var nextCalled atomic.Bool
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
nextCalled.Store(true)
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
claims := defaultBearerClaims()
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
prefix := oidc.sessionManager.GetCookiePrefix()
req.AddCookie(&http.Cookie{Name: prefix + "main", Value: "irrelevant"})
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
// Cookie path consumed the request; bearer was ignored. Since the
// cookie is empty, the cookie path will either 302 to /authorize or
// return 401 — in either case, next must NOT be called.
if nextCalled.Load() {
t.Fatalf("next must not be called when bearer is ignored due to cookie precedence")
}
}
func TestServeHTTP_Bearer_BearerOverridesCookie(t *testing.T) {
t.Parallel()
var nextCalled atomic.Bool
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
nextCalled.Store(true)
w.WriteHeader(http.StatusOK)
})
oidc := makeBearerOIDC(t, next)
oidc.bearerOverridesCookie = true
claims := defaultBearerClaims()
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
prefix := oidc.sessionManager.GetCookiePrefix()
req.AddCookie(&http.Cookie{Name: prefix + "main", Value: "irrelevant"})
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if !nextCalled.Load() || rw.Code != http.StatusOK {
t.Fatalf("expected bearer to win with override; status=%d called=%v", rw.Code, nextCalled.Load())
}
}
func TestServeHTTP_Bearer_OversizedToken(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for oversized token")
})
oidc := makeBearerOIDC(t, next)
huge := strings.Repeat("a", AccessTokenConfig.MaxLength+1)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+huge)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_MalformedJWT(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatalf("next must not run for malformed JWT")
})
oidc := makeBearerOIDC(t, next)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer not.jwt") // 1 dot
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
if rw.Code != http.StatusUnauthorized {
t.Fatalf("status=%d, want 401", rw.Code)
}
}
func TestServeHTTP_Bearer_FeatureOffPassesThrough(t *testing.T) {
t.Parallel()
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Should not be reached: cookie path runs and (with no session)
// will redirect or 401. We assert no panic / next not called.
t.Fatalf("next must not run when bearer is off and no valid session exists")
})
oidc := makeBearerOIDC(t, next)
oidc.enableBearerAuth = false
claims := defaultBearerClaims()
token := makeBearerJWT(t, defaultBearerHeader(), claims)
seedVerified(t, oidc, token, claims)
req := httptest.NewRequest("GET", "/api/work", nil)
req.Header.Set("Authorization", "Bearer "+token)
rw := httptest.NewRecorder()
oidc.ServeHTTP(rw, req)
// Expect non-200: either 302 to /authorize or 401. The point is the
// bearer pipeline didn't run.
if rw.Code == http.StatusOK {
t.Fatalf("expected non-200 when bearer is off; got %d", rw.Code)
}
}
// =============================================================================
// Startup validation tests
// =============================================================================
func TestStartupValidation_BearerRequiresAudience(t *testing.T) {
t.Parallel()
cfg := CreateConfig()
cfg.ProviderURL = "https://issuer.example.com"
cfg.ClientID = "id"
cfg.ClientSecret = "secret"
cfg.CallbackURL = "/oauth/callback"
cfg.SessionEncryptionKey = "0123456789abcdef0123456789abcdef0123456789abcdef"
cfg.EnableBearerAuth = true
cfg.Audience = ""
_, err := New(context.Background(), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}), cfg, "bearer-test")
if err == nil || !strings.Contains(err.Error(), "requires Audience") {
t.Fatalf("expected audience-required error, got %v", err)
}
}
func TestStartupValidation_BearerRejectsEmailIdentifier(t *testing.T) {
t.Parallel()
cfg := CreateConfig()
cfg.ProviderURL = "https://issuer.example.com"
cfg.ClientID = "id"
cfg.ClientSecret = "secret"
cfg.CallbackURL = "/oauth/callback"
cfg.SessionEncryptionKey = "0123456789abcdef0123456789abcdef0123456789abcdef"
cfg.EnableBearerAuth = true
cfg.Audience = "https://api.example.com"
cfg.BearerIdentifierClaim = "email"
_, err := New(context.Background(), http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}), cfg, "bearer-test")
if err == nil || !strings.Contains(err.Error(), "bearerIdentifierClaim=\"email\"") {
t.Fatalf("expected email-identifier rejection, got %v", err)
}
}
// =============================================================================
// Principal invariants
// =============================================================================
func TestBuildPrincipalFromSession_NoIdentifier(t *testing.T) {
t.Parallel()
oidc := &TraefikOidc{logger: NewLogger("error")}
if p := oidc.buildPrincipalFromSession(nil); p != nil {
t.Fatalf("nil session must produce nil principal")
}
}
+250
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@@ -0,0 +1,250 @@
# Bearer Token (M2M) Authentication
Opt-in path that lets API clients present `Authorization: Bearer <jwt>` to
authenticate without going through the cookie-based OIDC redirect flow.
Designed for machine-to-machine (M2M) traffic — services calling other
services with tokens minted by your OIDC provider.
The bearer path lives next to the cookie path: both go through the same
post-auth pipeline (`forwardAuthorized`) that injects identity headers,
checks `allowedRolesAndGroups`, applies security headers, and forwards to
the backend. The only thing that differs is how the principal is established
for that single request.
## Quick start
```yaml
enableBearerAuth: true
audience: https://api.example.com # REQUIRED when bearer is enabled
clientID: my-api-client-id
providerURL: https://issuer.example.com
sessionEncryptionKey: <32+-byte secret>
callbackURL: /oauth2/callback
```
That is the minimum. Everything else has a secure default.
## Obtaining bearer tokens from your OIDC provider
The middleware only **validates** bearer tokens — minting them is the IdP's job. For M2M traffic the canonical mint flow is OAuth 2.0 **`client_credentials`** (RFC 6749 §4.4); some providers require **JWT bearer assertion** (RFC 7523) instead.
```
┌────────────┐ POST /token ┌──────────┐
│ client │ ───────────────────────────────►│ IdP │
│ (service) │ grant_type=client_credentials │ /token │
│ │ client_id=… │ │
│ │ client_secret=… (or JWT) │ │
│ │ audience=https://api.… ←── critical │
│ │ scope=api:read … │
│ │ ◄───────────────────────────────│ │
│ │ access_token (JWT) │ │
└────────────┘ └──────────┘
│ GET /protected
│ Authorization: Bearer <access_token>
Your service (behind Traefik + this plugin)
```
The IdP returns a JWT signed by the same JWKs the middleware already trusts (it discovers them from `providerURL`/.well-known). On the first protected request, the middleware verifies signature + issuer + **audience** + `exp` + identifier claim, then forwards downstream with `X-Forwarded-User` set.
### Minimal worked example (Auth0-shape)
```bash
# 1. Mint a token
curl -s -X POST https://issuer.example.com/oauth/token \
-H 'Content-Type: application/json' \
-d '{
"grant_type": "client_credentials",
"client_id": "your-m2m-client-id",
"client_secret": "your-m2m-client-secret",
"audience": "https://api.example.com",
"scope": "api:read api:write"
}'
# → {"access_token":"eyJhbGciOiJSUzI1NiIs…","token_type":"Bearer","expires_in":86400,…}
# 2. Use it
curl -H 'Authorization: Bearer eyJhbGciOiJSUzI1NiIs…' https://api.example.com/protected
```
The `audience` field in the token request **must match** the `audience` you configured on the middleware. Mismatch → 401 with `Bearer error="invalid_token"`.
### Per-provider quick reference
| Provider | Grant | Token endpoint | Audience parameter | Notes |
|---|---|---|---|---|
| **Auth0** | `client_credentials` | `https://TENANT.auth0.com/oauth/token` | `audience=<your API identifier>` | Register an "API" + "Machine to Machine Application" authorised against that API. Without `audience` you get an opaque /userinfo token, which the bearer path rejects. See `docs/AUTH0_AUDIENCE_GUIDE.md`. |
| **Okta** | `client_credentials` | `https://TENANT.okta.com/oauth2/default/v1/token` | Configured in the authorization server; default `aud` is the auth-server URL | Service app must enable the `client_credentials` flow and be granted the requested scopes. |
| **Keycloak** | `client_credentials` | `https://kc/realms/REALM/protocol/openid-connect/token` | Configure an "Audience" mapper on a client scope, or use `client_id` as the audience | Client must have `serviceAccountsEnabled: true` plus role mappings. |
| **Entra ID / Azure AD** | `client_credentials` (v2.0 endpoint) | `https://login.microsoftonline.com/TENANT/oauth2/v2.0/token` | Pass `scope=<App ID URI>/.default`; `aud` ends up being the API's App ID URI | Requires an App Registration + API permissions + admin consent. **Use the v2.0 endpoint** — v1 issues Microsoft-proprietary access tokens that are opaque to non-Microsoft clients. |
| **AWS Cognito** | `client_credentials` | `https://YOUR_DOMAIN.auth.REGION.amazoncognito.com/oauth2/token` | Scopes from a "Resource Server" attached to your User Pool | App client must have `client_credentials` flow enabled. Use HTTP **Basic** auth header for `client_id:client_secret`. |
| **GitLab** | `client_credentials` | `https://gitlab.com/oauth/token` | Audience matches the GitLab issuer | Rarely used for protecting external APIs; better suited for GitLab's own resources. |
| **Google** | **JWT bearer (RFC 7523)***not* `client_credentials` | `https://oauth2.googleapis.com/token` | Signed assertion JWT carries `aud=https://oauth2.googleapis.com/token`; resulting access token is **opaque** unless you specifically request a Google-issued JWT for your API | Google service-account flow is not the best fit for this middleware (opaque tokens are rejected on the bearer path). Run Auth0 / Okta / Keycloak in front, or use ID-token-based flows on the cookie path. |
### RFC 7523 (JWT bearer assertion) — secretless alternative
When shared secrets are forbidden (FAPI, internal compliance), swap `client_secret` for a signed JWT assertion:
```
POST /token
grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer
assertion=<JWT signed by the client's private key>
```
The assertion JWT carries `iss=<client_id>`, `sub=<client_id>`, `aud=<token endpoint>`, `exp`. The IdP verifies the signature against a public key you've pre-registered and returns an access token.
This middleware already supports JWT assertions on the *middleware → IdP* hop via `clientAuthMethod: private_key_jwt` (see `docs/CONFIGURATION.md`). For the *client → IdP* hop, the same pattern applies — the client signs its own assertion.
### Operational notes
- **Token TTL is typically 124 hours.** Clients should refresh on `401`, not on a polling timer — saves the IdP.
- **Cache and reuse tokens.** The middleware caches verified tokens too, so repeated presentations are cheap. Clients SHOULD reuse a token until ~80 % of `expires_in`.
- **JWKS rotation is transparent.** The middleware auto-refreshes its JWKS cache when the IdP rotates keys. Clients don't need to do anything.
- **Revocation is generally not per-token** with `client_credentials`. If you need real-time revocation, set `requireTokenIntrospection: true` on the middleware and the IdP is consulted on every cache miss.
- **`scope` vs `audience`.** Scope says *what the client may do*; audience says *which service the token is for*. The middleware enforces audience; the backend service should enforce scope.
- **Secret hygiene.** Store `client_secret` in a secrets manager (Vault, AWS Secrets Manager, Kubernetes `Secret`). For higher assurance, switch the client to `private_key_jwt` (no shared secret at all).
### Quickest validation loop
```bash
# 1. Mint
TOKEN=$(curl -s -X POST https://issuer.example.com/oauth/token \
-H 'Content-Type: application/json' \
-d '{"grant_type":"client_credentials","client_id":"…","client_secret":"…","audience":"https://api.example.com"}' \
| jq -r .access_token)
# 2. Inspect claims to confirm aud/iss/exp match the middleware config
echo "$TOKEN" | cut -d. -f2 | base64 -d 2>/dev/null | jq
# 3. Hit the protected route
curl -i -H "Authorization: Bearer $TOKEN" https://api.example.com/protected
```
`HTTP/1.1 200` with `X-Forwarded-User` on the backend confirms the loop works end-to-end. `401` with `WWW-Authenticate: Bearer error="invalid_token"` plus a middleware debug log explaining the rejection (audience mismatch, ID token presented, `iat` outside the 24h window, etc.) confirms the hardening is firing as designed.
## Threat model and design rules
Bearer authentication has materially different security properties from
cookie sessions: no `HttpOnly`/`Secure`/`SameSite` shielding, the token is
visible in headers and logs, and it's easier to exfiltrate. The bearer path
treats every one of these as a first-class concern.
| Property | Behaviour | Why |
|---|---|---|
| Default state | `enableBearerAuth=false` | Bearer is opt-in; existing deployments observe no change. |
| Audience | **Mandatory.** Startup fails if `audience` is empty when bearer is enabled. | Eliminates the "token issued for service B accepted by service A" confusion attack. |
| Token format | JWT only (3 segments, JOSE-encoded). Opaque tokens are not accepted on the bearer path. | Matches the validation pipeline; opaque tokens require introspection only and bypass JWT-specific defences. |
| `alg` allowlist | Hard-pinned asymmetric: `RS256/384/512`, `PS256/384/512`, `ES256/384/512`. Checked **before** any JWKS fetch. | Denies `alg=none` and `alg=HS*` probes; prevents attacker noise from amplifying into JWKS round-trips. |
| `kid` hardening | Max 256 bytes; charset `[A-Za-z0-9._\-=]`. Checked **before** JWKS fetch. | Prevents cache-key explosion / pathological-`kid` JWKS amplification. |
| Token type | ID tokens are explicitly rejected (`nonce` claim, `typ: at+jwt`, `token_use=id`, scope/aud heuristics — reuses the existing `detectTokenType` helper). | ID tokens are not API credentials; treating them as such is classic token confusion. |
| Multi-audience | When `aud` is an array of length > 1, the token must carry `azp == clientID`. | OIDC §2 hardening against tokens minted for one client being replayed by another. |
| `iat` upper-age | Rejects tokens older than `maxTokenAgeSeconds` (default 24h). | Bounds clock-manipulation / forever-token abuse, even if `exp` is far in the future. |
| Identifier claim | `bearerIdentifierClaim` (default `"sub"`). Resolved value drives `X-Forwarded-User`. | Decoupled from the cookie path's `UserIdentifierClaim` (default `email`) so the M2M flow can never accidentally trust an unverified email. |
| Identifier sanitisation | Length cap (`maxIdentifierLength`, default 256). Rejects control chars, Unicode bidi-overrides (U+202AU+202E, U+2066U+2069), and the delimiters `, ; =`. | Defence in depth against downstream header injection / log injection / admin-UI spoofing. |
| JTI replay marking | Bearer path skips the JTI **Set** (so the same token can be reused until `exp`) but the **Get** stays active. | Allows legitimate bearer reuse without false-positive replay detection; revoked tokens (added to the blacklist by `RevokeToken`) still fail immediately. |
| Mixed bearer + cookie | **Cookie wins by default.** Flip to bearer-wins with `bearerOverridesCookie=true`. | Safer against browser/extension/proxy bearer injection scenarios. The cookie is the authoritative authenticator when present. |
| `Authorization` strip | `stripAuthorizationHeader=true` by default. | Keeps the raw token out of downstream services and their logs. |
| Excluded URLs | `Authorization` is stripped on excluded paths when `enableBearerAuth=true`. | Prevents bearer leakage into public health/metrics endpoint logs and prevents recon via excluded paths. |
| Per-IP throttle | After `bearerFailureThreshold` consecutive 401s from one source IP within `bearerFailureWindowSeconds`, further bearer requests from that IP return `429 Too Many Requests` + `Retry-After` for `bearerFailurePenaltySeconds`. | Limits offline-guessing-style attacks and protects the shared rate-limiter / JWKS endpoint. |
| Optional introspection | `requireTokenIntrospection=true` calls RFC 7662 introspection on every cache miss. Introspection result is cached briefly. Endpoint failure returns `503` (distinguishes infra outage from credential rejection). | Real-time revocation for high-assurance environments. Adds per-request IdP latency. |
| Response shape | `401 Unauthorized` with generic body. `WWW-Authenticate: Bearer error="invalid_token"` per RFC 6750 §3 (toggleable via `bearerEmitWWWAuthenticate`). `403` for roles/groups denial. `429` for throttle. `503` for introspection-endpoint outage. | Auditable from spec to code; reason categories never leak into the response body. |
| Logging | Failure reason + identifier hash (SHA-256 truncated to 8 hex chars) logged at debug. Raw tokens are never logged. | Audit trail without secrets-in-logs. |
## Configuration reference
| Field | Default | Description |
|---|---|---|
| `enableBearerAuth` | `false` | Master switch for the bearer path. |
| `audience` | (unset) | **Required** when `enableBearerAuth=true`. Reuses the existing global `audience` field. |
| `bearerIdentifierClaim` | `"sub"` | JWT claim used as the principal identifier. `"email"` is rejected at startup. |
| `stripAuthorizationHeader` | `true` | Remove the `Authorization` header before forwarding to the backend. Disable only when a downstream needs to re-verify the bearer. |
| `bearerEmitWWWAuthenticate` | `true` | Include `WWW-Authenticate: Bearer error="..."` on 401 responses (RFC 6750 §3). Disable to reduce recon signal. |
| `bearerOverridesCookie` | `false` | Cookie wins when both are present (default). Set `true` for the AWS/GCP/Kubernetes bearer-wins convention. |
| `maxTokenAgeSeconds` | `86400` | Upper bound on `iat` claim age (24h). Set `0` to disable the check (not recommended). |
| `maxIdentifierLength` | `256` | Length cap for the post-sanitisation identifier. |
| `bearerFailureThreshold` | `20` | Consecutive 401s from one IP that trip the throttle. |
| `bearerFailureWindowSeconds` | `60` | Rolling window over which 401s are counted. |
| `bearerFailurePenaltySeconds` | `60` | Duration of the 429 penalty box after the threshold trips. |
| `requireTokenIntrospection` | `false` | Call RFC 7662 introspection on every cache miss. Adds per-request IdP latency. |
## What the bearer path does NOT do
- **Human-user / browser flows.** The bearer path is M2M-only in this
iteration. Browser SPAs that want to attach a bearer to fetch calls work
if your backend treats them as machine clients, but the spec defaults are
tuned for service-to-service traffic.
- **Opaque access tokens.** Tokens must be JWTs. Introspection is a
revocation overlay on top of JWT verification, not a substitute for it.
- **`email_verified` enforcement.** The bearer path rejects `email` as the
identifier claim at startup precisely because `email_verified` is not
enforced in this iteration. Adding human-user bearer support is a
follow-up that must include this check.
- **mTLS / API keys.** Out of scope. The `principal` abstraction enables
adding these later as additional auth methods that produce a principal
for the shared `forwardAuthorized` pipeline.
- **SSE / WebSocket bypass with bearer.** Bypass paths keep their existing
cookie-only behaviour; bearer headers are ignored on those endpoints.
Documented limitation; widen by removing the bypass if you need bearer on
streaming endpoints.
## Operational guidance
- **Always set `strictAudienceValidation: true` when bearer is enabled.**
Startup logs a recommendation if you don't.
- **Set a tight `maxTokenAgeSeconds`** for environments where tokens are
expected to be minted frequently — the default 24h is conservative.
- **Enable `requireTokenIntrospection`** if your IdP supports it and
revocation latency matters. Bearer-path introspection caches results for
a short window per token.
- **Monitor 429s.** Sustained 429 traffic indicates either a buggy client
loop or an active credential-stuffing attempt. The throttle is your
primary signal for both.
- **`stripAuthorizationHeader=false` extends the token's blast radius** to
every downstream service that sees the request. Treat those services'
logs as token stores.
- **Bearer reuse is normal.** Don't enable per-token rate limiting; that's
what `bearerFailureThreshold` is for (per-IP, not per-token).
- **Cookie-wins is the safer default.** Only flip `bearerOverridesCookie`
if you control all clients and have audited that none of them present a
cookie alongside a bearer they don't intend to authenticate with.
## Failure response matrix
| Trigger | Status | Body | `WWW-Authenticate` |
|---|---|---|---|
| Empty bearer after prefix | 401 | `Unauthorized` | `Bearer error="invalid_request"` |
| Token over `MaxLength` | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Not a 3-segment JWT | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Disallowed `alg` (e.g. none, HS*) | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Missing / oversized / bad-charset `kid` | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Signature / issuer / audience / `exp` failure | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| `iat` older than `maxTokenAgeSeconds` | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Multi-audience token without matching `azp` | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Detected as ID token | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| JTI blacklisted (revoked) | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Introspection reports `active=false` | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Introspection endpoint failure | 503 | `Service Unavailable` | (none) |
| Identifier claim missing / empty | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Identifier fails sanitisation | 401 | `Unauthorized` | `Bearer error="invalid_token"` |
| Per-IP failure threshold tripped | 429 | `Too Many Requests` | (none); `Retry-After: <bearerFailurePenaltySeconds>` |
| Roles / groups not allowed | 403 | `Access denied` | (none) |
## Known follow-ups (deferred)
These are documented as future work, not blockers:
- **Human-user bearer with `email_verified` enforcement.** Requires
decoupling the email-claim guard from the startup rejection and adding a
per-request `email_verified=true` check.
- **Introspection respects `client_assertion`.** The existing introspection
helper uses `client_secret_basic` only; operators on `private_key_jwt`
will see introspection silently use basic auth.
- **Per-route bearer configuration.** Single middleware-wide setting in this
iteration.
## References
- [PR design spec](superpowers/specs/2026-05-18-bearer-token-auth-design.md) — full design rationale, alternatives considered, and per-section sign-off history.
- [RFC 6750](https://www.rfc-editor.org/rfc/rfc6750) — Bearer Token Usage.
- [RFC 7662](https://www.rfc-editor.org/rfc/rfc7662) — OAuth 2.0 Token Introspection.
- [RFC 9068](https://www.rfc-editor.org/rfc/rfc9068) — JWT Profile for OAuth 2.0 Access Tokens.
+20
View File
@@ -261,6 +261,26 @@ strictAudienceValidation: true
| `disableReplayDetection` | bool | `false` | Disable JTI-based replay attack detection |
| `allowPrivateIPAddresses` | bool | `false` | Allow private IPs in provider URLs |
### Bearer-token (M2M) authentication
Opt-in path that accepts `Authorization: Bearer <jwt>` instead of the cookie
session flow. M2M-only, default off, audience-mandatory. See
[docs/BEARER_AUTH.md](BEARER_AUTH.md) for the threat model and operational
guidance.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `enableBearerAuth` | bool | `false` | Master switch. Startup fails if true with empty `audience` or with `bearerIdentifierClaim=email`. |
| `bearerIdentifierClaim` | string | `"sub"` | JWT claim used as the principal identifier. `"email"` is rejected at startup. |
| `stripAuthorizationHeader` | bool | `true` | Strip `Authorization` from forwarded requests after successful bearer auth. |
| `bearerEmitWWWAuthenticate` | bool | `true` | Emit RFC 6750 `WWW-Authenticate: Bearer error="..."` hints on 401. |
| `bearerOverridesCookie` | bool | `false` | Cookie wins when both bearer and cookie are present (default). Set true for bearer-wins. |
| `maxTokenAgeSeconds` | int64 | `86400` | Upper bound on `iat` claim age (24h). 0 disables the check. |
| `maxIdentifierLength` | int | `256` | Length cap on the sanitised principal identifier. |
| `bearerFailureThreshold` | int | `20` | Consecutive 401s from one source IP that trip the throttle. |
| `bearerFailureWindowSeconds` | int | `60` | Rolling window for counting 401s. |
| `bearerFailurePenaltySeconds` | int | `60` | 429 + `Retry-After` duration after the threshold trips. |
---
## Session Management
@@ -0,0 +1,459 @@
# Bearer Token Authentication — Design Spec
- **Date**: 2026-05-18
- **Status**: Design — pending implementation plan
- **Supersedes**: PR #93 (broken implementation; recommended to close in favour of this design)
## 1. Summary
Add an opt-in path that lets API clients (machine-to-machine) authenticate by presenting a signed access token in the `Authorization: Bearer <token>` header, bypassing the cookie-based OIDC redirect flow. Identity, roles, and authorization checks remain consistent with the existing cookie path; the only thing that changes is how the principal is established for that single request.
The feature is implemented by extracting a shared `forwardAuthorized` pipeline from the existing `processAuthorizedRequest`, introducing a `principal` value type, and adding a small bearer-specific entrypoint that builds a principal directly from a verified JWT — without synthesising a fake `SessionData`.
## 2. Motivation
PR #93 attempted this feature by building an in-memory `SessionData` from JWT claims and reusing `processAuthorizedRequest`. The approach has three latent defects:
1. The synthetic session omits `mainSession.Values["user_identifier"]`. `processAuthorizedRequest` reads it via `GetUserIdentifier()`; when empty it bails to `defaultInitiateAuthentication` and issues an OIDC redirect. The feature is non-functional in practice despite the unit test passing.
2. `verifyToken` accepts both ID tokens (audience match against `clientID`) and access tokens. ID tokens are not API credentials; treating them as such is a classic token-confusion vector.
3. `verifyToken` adds JTI to the replay blacklist on first verify. Once the verified-token cache evicts, subsequent reuse of the same bearer token triggers a false-positive replay rejection.
Rather than patch a synthetic-session approach that will keep generating bugs as `SessionData` evolves, this spec replaces it with a cleaner abstraction where session lifecycle and post-auth header injection live in separate units.
## 3. Goals
- Accept `Authorization: Bearer <jwt>` from M2M clients, validate the token, and forward the request downstream with identity headers populated.
- Enforce the same `allowedRolesAndGroups` policy as the cookie path.
- Default-off; safe defaults when enabled (audience required, ID tokens rejected, identifier sanitised).
- No behavioural change to the cookie path. Existing tests must continue to pass without modification.
## 4. Non-Goals
- Human-user / browser flows. Bearer is M2M-only in this iteration.
- Pure opaque access tokens on the bearer path. Tokens must be JWTs; introspection (RFC 7662) is supported *on top of* JWT verification for revocation state, not as a substitute for it.
- mTLS, API keys, or any other auth method. The `principal` abstraction enables them later, but they are not delivered here.
- Per-route bearer configuration. Single middleware-wide setting.
## 5. Decided Requirements
| Topic | Decision |
|---|---|
| Consumer type | Machine-to-machine (M2M) only |
| Token format | JWT only (signature, issuer, audience, exp) |
| Audience | Mandatory when feature enabled; startup fails if `Audience == ""` |
| Token type | Access tokens only; ID tokens explicitly rejected |
| Revocation | JWT-only verification by default; introspection (RFC 7662) opt-in via existing `RequireTokenIntrospection` |
| Identity claim | New `BearerIdentifierClaim` config (string, default `"sub"`). Bearer path reads this claim exclusively; does NOT use `UserIdentifierClaim` (which defaults to `"email"` and drives the cookie path). Resolved value must be a non-empty string. `sub` is mandatory per `jwt.go:416` regardless, so even with a different `BearerIdentifierClaim` the token must still carry a valid `sub`. Decoupling avoids the M2M-vs-human-user identity-claim conflict and the email-spoofing footgun. |
| Identifier sanitisation | Reject value containing any `unicode.IsControl` char, any Unicode bidi-override (U+202AU+202E, U+2066U+2069), leading/trailing whitespace, commas, semicolons, equals signs. Max length 256 bytes. |
| Token classifier | **Reuse existing `detectTokenType(jwt, token)` at `token_manager.go:187-303`** which already handles `nonce`, `typ: at+jwt`, `token_use`, `scope`, and aud-vs-clientID priority. Bearer path rejects any token where `detectTokenType == true` (ID token). Do not invent a parallel classifier. |
| Algorithm pinning | Hard-pin `alg ∈ {RS256, RS384, RS512, PS256, PS384, PS512, ES256, ES384, ES512}`, enforced **before** JWKS lookup on the bearer path. Prevents wasted JWKS fetches for `alg=none`/HS attacker probes. |
| `kid` hardening | `kid` ≤ 256 bytes, charset `[A-Za-z0-9._\-=]`. Reject before JWKS lookup. |
| Token age | Bearer path enforces `now - iat <= MaxTokenAgeSeconds` (default 86400 / 24h, configurable). Cookie path unchanged. |
| Multi-audience policy | If `aud` is an array (length > 1), require `azp` claim to be present and equal to `clientID`. Single-string `aud` unaffected. |
| Mixed bearer + cookie precedence | **Cookie wins by default** when both are presented (safer for browser scenarios). Operator opt-in: `BearerOverridesCookie=true` to flip. Either way, a warning is logged on the request. |
| Bearer + excluded URL | `Authorization` header is **stripped** before forwarding when the request hits an excluded URL. Prevents bearer leaking into public endpoints' downstream logs and prevents recon via excluded paths. |
| Per-source bearer 401 throttle | New sharded cache `failedBearerAttempts` keyed by client IP. After N (default 20) consecutive 401s from one IP within 1 minute, reject further bearer requests from that IP with 429 for 60s. Applied BEFORE `verifyToken` to deny JWKS amplification. |
| `Authorization` header passthrough | New `StripAuthorizationHeader` config, default `true` |
| Roles/groups gating | Same `allowedRolesAndGroups` rules as cookie path |
| Default state | `EnableBearerAuth` = `false` |
| JTI replay marking | Suppressed on bearer path; cookie path unchanged |
| Failure response shape | 401 with generic body; `WWW-Authenticate: Bearer error="invalid_token"` per RFC 6750 |
| Introspection endpoint outage | 503 (distinguishes infra outage from token rejection) |
| Mixed bearer + cookie | Bearer wins; cookie ignored on that request |
| SSE/WS bypass + bearer | Bypass paths keep cookie-only check; bearer header ignored on SSE/WS |
## 6. Architecture
```
┌──────────────────┐
HTTP req ──► │ ServeHTTP │ (existing entry; adds bearer detection)
└─────────┬────────┘
┌───────────┴────────────┐
▼ ▼
cookie / session bearer (Authorization: Bearer …)
│ │
▼ ▼
┌────────────────┐ ┌────────────────────┐
│ buildPrincipal │ │ buildPrincipal │
│ FromSession() │ │ FromBearerToken() │
└────────┬───────┘ └─────────┬──────────┘
│ produces *principal │
└──────────────┬───────────┘
┌────────────────────────────┐
│ forwardAuthorized(rw,req,p)│ (shared pipeline)
│ • roles/groups gate │
│ • header injection │
│ • header templates │
│ • security headers │
│ • cookie stripping │
│ • next.ServeHTTP │
└────────────────────────────┘
```
**Invariant**: `forwardAuthorized` never touches session storage. Session-specific concerns (Save, IsDirty, backchannel-logout invalidation) stay inside `processAuthorizedRequest` around the call to `forwardAuthorized`.
**Feature gate**: when `EnableBearerAuth == false`, the bearer-detection check in `ServeHTTP` is a no-op. Existing deployments observe byte-identical behaviour.
## 7. Components
### 7.1 `principal` type (new file `principal.go`)
```go
type principalSource int
const (
sourceSession principalSource = iota
sourceBearer
)
type principal struct {
Identifier string // drives X-Forwarded-User
Email string // optional, "" for M2M
Subject string // sub claim
ClientID string // azp / client_id, M2M caller
Claims map[string]interface{} // raw claims for templates / groups
AccessToken string // for X-Auth-Request-Token (gated by minimalHeaders)
IDToken string // "" on bearer path
RefreshToken string // "" on bearer path
Source principalSource
}
```
Pure data. No methods that mutate it. No I/O. No manager pointer.
### 7.2 `buildPrincipalFromSession(*SessionData) *principal` (new in `principal.go`)
Read-only adapter over existing `SessionData` getters: `GetUserIdentifier`, `GetEmail`, `GetAccessToken`, `GetIDToken`, `GetRefreshToken`, cached claims via `GetIDTokenClaims`. Does not write back to the session. This is the only function that still knows about `SessionData`.
### 7.3 `buildPrincipalFromBearerToken(token string) (*principal, error)` (new in `bearer_auth.go`)
1. **Length / format guards**: `len(token) <= AccessTokenConfig.MaxLength`, exactly two dots, non-empty after trim.
2. **Parse header for early alg/kid pinning** (without trusting payload): decode JOSE header; reject if `alg` ∉ asymmetric allowlist; reject if `kid` missing, > 256 bytes, or contains chars outside `[A-Za-z0-9._\-=]`. This happens **before** JWKS lookup so attacker noise doesn't amplify into JWKS fetches.
3. **Per-IP 401 throttle check**: if this IP is in the `failedBearerAttempts` penalty box, return 429 immediately.
4. `t.verifyToken(token, verifyOpts{skipReplayMarking: true})` — reuses signature, issuer, audience, expiration, JTI Get (replay detection). The `skipReplayMarking` flag gates ONLY the JTI Set at `token_manager.go:108-143`; the JTI Get at `token_manager.go:44-47, 80-89` remains active so revoked tokens (via `RevokeToken` adding to blacklist) are still rejected.
5. **Re-parse claims** (`parseJWT(token)` is cheap and already done internally; reuse via a single decode if practical).
6. **Token-type guard**: call existing `detectTokenType(jwt, token)` (`token_manager.go:187-303`). Reject when it returns `true` (ID token). Belt-and-braces: also reject if `claims["nonce"]` is a non-empty string or `claims["token_use"] == "id"`.
7. **Multi-audience hardening**: if `claims["aud"]` is a `[]interface{}` with length > 1, require `claims["azp"]` to be a non-empty string equal to `t.clientID`; reject otherwise.
8. **`iat` upper-age bound**: reject when `time.Now().Unix() - int64(claims["iat"].(float64)) > MaxTokenAgeSeconds` (default 86400).
9. **Optional introspection**: if `requireTokenIntrospection` is set, call `introspectToken`; reject if `active == false` (401); surface 503 on transport failure. Bearer-path introspection cache TTL is capped at 60s (not 5min) to keep the "real-time revocation" promise close to true.
10. **Identifier resolution**: read `t.bearerIdentifierClaim` (defaults to `"sub"`); do NOT use `t.userIdentifierClaim` (cookie path's setting, default `email`). The bearer path does NOT fall back to other claims because `jwt.Verify` already enforces non-empty `sub` (`jwt.go:416-419`). Empty/missing identifier → 401.
11. **Identifier sanitisation**: trim, then reject if length > 256 OR contains any of: `unicode.IsControl`, bidi-override (U+202AU+202E, U+2066U+2069), `,`, `;`, `=`.
12. Return `&principal{ Source: sourceBearer, … }`.
On any failure path: increment the per-IP `failedBearerAttempts` counter; return the appropriate HTTP status (401 / 403 / 429 / 503) without revealing the failure reason in the response body. Reason is logged at debug only, with the identifier (if resolved) hashed via SHA-256 truncated to 8 hex chars.
### 7.4 `forwardAuthorized(rw, req, *principal)` (new in `middleware.go`, extracted)
The shared post-auth pipeline. Lifted verbatim from the existing `processAuthorizedRequest`:
1. Roles/groups extraction via existing `extractGroupsAndRolesFromClaims`.
2. `allowedRolesAndGroups` gate (existing logic).
3. Inject `X-Forwarded-User`, `X-User-Groups`, `X-User-Roles`.
4. Inject `X-Auth-Request-*` (gated by `minimalHeaders`).
5. Header templates.
6. Security headers.
7. Cookie strip when `stripAuthCookies`.
8. **New**: `Authorization` header strip when `stripAuthorizationHeader` AND `principal.Source == sourceBearer`.
9. `t.next.ServeHTTP(rw, req)`.
Does not call `Save`, does not check `IsDirty`. Session persistence stays with the cookie-path caller.
### 7.5 `handleBearerRequest(rw, req)` (new in `bearer_auth.go`)
```
1. Detect "Authorization: Bearer <token>" (case-insensitive prefix).
2. token = TrimSpace(authHeader[7:]); reject empty.
3. p, err := buildPrincipalFromBearerToken(token).
On err → 401 with WWW-Authenticate, log reason at debug.
4. forwardAuthorized(rw, req, p).
```
Target: ~40 lines.
### 7.6 Refactor of `processAuthorizedRequest` (modify `middleware.go`)
Splits along the principal boundary:
- Session-specific part (backchannel-logout invalidation, `IsDirty` / `Save`) stays in `processAuthorizedRequest`.
- Everything else moves to `forwardAuthorized`.
- `processAuthorizedRequest` ends with `forwardAuthorized(rw, req, buildPrincipalFromSession(session))`.
### 7.7 `verifyOpts` extension to `verifyToken` (modify `token_manager.go`)
Add a parameter struct:
```go
type verifyOpts struct {
skipReplayMarking bool // suppress JTI Set (token_manager.go:108-143); blacklist Get stays active
}
```
Both the type and field are unexported (internal-only knob). Signature change: `verifyToken(token string)` becomes `verifyToken(token string, opts verifyOpts)`. Existing callers pass `verifyOpts{}` (zero value = current behaviour). Bearer path passes `verifyOpts{skipReplayMarking: true}`.
**Critical semantics — must be reflected in implementation and tests:**
- `skipReplayMarking` only gates the **Set** at `token_manager.go:108-143` (the call adding the JTI to the blacklist and replay cache).
- The blacklist **Get** at `token_manager.go:44-47, 80-89` stays unconditionally active on the bearer path. Tokens revoked via `RevokeToken` (which adds the JTI to the blacklist) MUST still be rejected on the bearer path.
- Must NOT be implemented by mutating `t.disableReplayDetection` (struct field) — that would create a cross-request race that disables replay protection globally.
A targeted regression test exercises: bearer token verified once → admin calls `RevokeToken` adding the JTI to the blacklist → same token replayed → 401.
### 7.8 Config additions (modify `settings.go`)
```go
EnableBearerAuth bool `json:"enableBearerAuth,omitempty"`
BearerIdentifierClaim string `json:"bearerIdentifierClaim,omitempty"`
StripAuthorizationHeader bool `json:"stripAuthorizationHeader,omitempty"`
BearerEmitWWWAuthenticate bool `json:"bearerEmitWWWAuthenticate,omitempty"`
BearerOverridesCookie bool `json:"bearerOverridesCookie,omitempty"`
MaxTokenAgeSeconds int64 `json:"maxTokenAgeSeconds,omitempty"`
MaxIdentifierLength int `json:"maxIdentifierLength,omitempty"`
BearerFailureThreshold int `json:"bearerFailureThreshold,omitempty"`
BearerFailureWindowSeconds int `json:"bearerFailureWindowSeconds,omitempty"`
BearerFailurePenaltySeconds int `json:"bearerFailurePenaltySeconds,omitempty"`
```
Defaults (applied in `CreateConfig` for the bearer-related fields; values >0 only honoured when `EnableBearerAuth=true`):
- `EnableBearerAuth`: `false`.
- `BearerIdentifierClaim`: `"sub"`.
- `StripAuthorizationHeader`: `true`.
- `BearerEmitWWWAuthenticate`: `true` (RFC 6750 hint enabled by default; flip to false if recon-exposure is a concern).
- `BearerOverridesCookie`: `false` (cookie wins when both present; flip to `true` for the legacy/industry-default behaviour).
- `MaxTokenAgeSeconds`: `86400` (24h upper bound on `iat`).
- `MaxIdentifierLength`: `256`.
- `BearerFailureThreshold`: `20` (consecutive 401s per IP before throttle).
- `BearerFailureWindowSeconds`: `60`.
- `BearerFailurePenaltySeconds`: `60` (429 reply for this long after threshold tripped).
### 7.9 Startup validation (modify `main.go` `New()`)
- `EnableBearerAuth && Audience == ""` → fatal error.
- `EnableBearerAuth && !StrictAudienceValidation` → warning log (recommended hardening).
- `EnableBearerAuth && BearerIdentifierClaim == "email"` → fatal error (the bearer path is M2M and an `email` identifier without `email_verified` enforcement is a spoofing vector; default `BearerIdentifierClaim=sub` avoids this; explicit override to `email` is rejected).
- `EnableBearerAuth && MaxTokenAgeSeconds <= 0` → reset to default 86400 with info log.
- `EnableBearerAuth && BearerFailureThreshold <= 0` → reset to default 20 with info log.
## 8. Data Flow
### 8.1 Bearer path
```
ServeHTTP entry (pre-init paths unchanged: logout, backchannel, frontchannel, excluded URLs, SSE/WS bypass)
├─ enableBearerAuth == false? → fall through to cookie path
└─ enableBearerAuth == true AND Authorization starts with "Bearer "
handleBearerRequest
├─ format guards (empty, length, segment count)
verifyToken(token, verifyOpts{SkipReplayMarking: true})
│ signature, issuer, audience (strict), exp
classifyToken(claims) → reject ID tokens
if requireTokenIntrospection: introspectToken → active check
resolveIdentifier(claims) → sanitiseIdentifier
principal{Source: sourceBearer, …}
forwardAuthorized(rw, req, principal)
├─ roles/groups gate (403 on deny)
├─ header injection
├─ header templates
├─ security headers
├─ strip OIDC cookies (existing)
├─ strip Authorization header (new, when configured)
└─ next.ServeHTTP(rw, req)
```
### 8.2 Cookie path (refactored, semantically unchanged)
```
processAuthorizedRequest
1. Session validity / backchannel-logout invalidation (unchanged).
2. principal := buildPrincipalFromSession(session).
3. forwardAuthorized(rw, req, principal).
4. if session.IsDirty(): session.Save().
```
## 9. Error Handling
| Trigger | Status | Body | WWW-Authenticate | Debug log reason |
|---|---|---|---|---|
| Empty bearer after prefix | 401 | `Unauthorized` | `Bearer error="invalid_request"` | empty bearer token |
| Token over MaxLength | 401 | `Unauthorized` | `Bearer error="invalid_token"` | token exceeds max length |
| Not a 3-segment JWT | 401 | `Unauthorized` | `Bearer error="invalid_token"` | malformed JWT |
| Disallowed `alg` (e.g. none, HS*) | 401 | `Unauthorized` | `Bearer error="invalid_token"` | unsupported alg |
| Missing/oversized/bad-charset `kid` | 401 | `Unauthorized` | `Bearer error="invalid_token"` | invalid kid |
| Signature / issuer / aud / exp fail | 401 | `Unauthorized` | `Bearer error="invalid_token"` | reason from verifyToken (category only) |
| `iat` older than MaxTokenAgeSeconds | 401 | `Unauthorized` | `Bearer error="invalid_token"` | token too old (iat outside age bound) |
| Multi-aud without matching `azp` | 401 | `Unauthorized` | `Bearer error="invalid_token"` | multi-aud token without azp match |
| Detected as ID token | 401 | `Unauthorized` | `Bearer error="invalid_token"` | ID tokens not accepted on bearer path |
| JTI blacklisted (revoked) | 401 | `Unauthorized` | `Bearer error="invalid_token"` | token JTI in blacklist |
| Introspection `active=false` | 401 | `Unauthorized` | `Bearer error="invalid_token"` | token inactive at IdP |
| Introspection endpoint failure | 503 | `Service Unavailable` | (none) | introspection unavailable |
| Identifier claim missing/empty | 401 | `Unauthorized` | `Bearer error="invalid_token"` | no identifier claim |
| Identifier fails sanitisation | 401 | `Unauthorized` | `Bearer error="invalid_token"` | invalid identifier characters |
| Per-IP failure threshold tripped | 429 | `Too Many Requests` | (none); `Retry-After: <BearerFailurePenaltySeconds>` | source IP in penalty box |
| Roles/groups not allowed | 403 | `Access denied` | (none) | user not in allowedRolesAndGroups |
Responses never include token contents, never include the raw failure reason, and never set `Location` headers (API clients cannot follow redirects).
## 10. Edge Cases
1. **Both bearer header and cookie session present.** Cookie wins by default (safer against browser/extension/proxy bearer injection). `BearerOverridesCookie=true` flips to bearer-wins. Either way: WARN log includes both source markers so operators can audit.
2. **`Authorization: Basic …`.** Not bearer; cookie path runs as today.
3. **`Authorization: Bearer ` (trailing space, no value).** Empty after trim → 401.
4. **Mixed-case prefix (`bearer`, `BEARER`, `BeArEr`).** Case-insensitive prefix check; token value preserved verbatim.
5. **Multiple `Authorization` headers.** Use only the first (Go `http.Header.Get` default). Documented.
6. **Bearer during OIDC init wait.** Bearer requests also block on init: we need `issuerURL`, `audience`, JWKs ready. If init fails, bearer requests return 503 just like cookie requests.
7. **SSE / WebSocket bypass with bearer.** Bypass paths keep cookie-only behaviour. Operators who want bearer on streaming endpoints must remove SSE/WS bypass. Documented.
8. **Logout endpoint with bearer.** Logout runs before bearer detection. Treated as cookie-session logout; bearer token revocation requires IdP-side action.
9. **Excluded URLs with bearer.** Bypass excluded URLs as today; bearer not validated on excluded paths. ADDITIONALLY: `Authorization: Bearer` is stripped from the request before forwarding so the token can't leak into the excluded endpoint's downstream logs / metrics scrapers / health checks.
10. **Concurrent identical bearer requests.** Existing `tokenCache` is concurrency-safe; no new locking.
11. **Client rotates token between requests.** Independent verification per token; independent cache entries.
12. **Clock skew.** Use existing `jwt.Verify` leeway. (If absent, add ±30s as a separate change; out of scope here.)
## 11. Testing Strategy
### 11.1 Integration tests (new `bearer_auth_test.go`)
Table-driven test against a real `httptest.Server` and the full `ServeHTTP` flow. Coverage matrix:
- Valid access token + allowed roles → 200, `next` ran, `X-Forwarded-User` set.
- Valid token without configured roles → 200.
- Wrong audience, expired, tampered signature → 401, `next` did not run.
- ID token presented → 401 (`ID tokens not accepted`).
- Malformed JWT (2 segments) → 401.
- Oversized token (> MaxLength) → 401.
- Empty bearer → 401.
- Missing identifier claim → 401.
- Identifier containing `\r\n` → 401.
- `allowedRolesAndGroups` mismatch → 403.
- `allowedRolesAndGroups` match → 200.
- `EnableBearerAuth=false` + bearer header → cookie path runs (302 to `/authorize`).
- Bearer + valid cookie session → bearer wins, 200.
- `StripAuthorizationHeader=true` → downstream sees no `Authorization`.
- `StripAuthorizationHeader=false` → downstream sees `Authorization`.
- Case variants (`bearer`, `BEARER`) → 200.
- SSE bypass + bearer → cookie-only check applies (bearer ignored).
- **Replay regression**: same token 1000 times in a row → all 200.
- **Cache-evict regression**: same token, force-evict `tokenCache` between iterations (call `tokenCache.Delete` directly), replay → still 200 (verifies `skipReplayMarking` doesn't poison the blacklist).
- **Revocation-while-bearer regression**: bearer token verified once → admin calls `RevokeToken` adding JTI to blacklist → same token presented → 401 (verifies blacklist Get stays active on bearer path even with `skipReplayMarking` set).
- **Alg-pin: token signed with `alg=none`** → 401, no JWKS fetch happens (verify with a counting mock).
- **`kid` injection: 50KB random kid** → 401 immediately, no JWKS fetch.
- **Per-IP throttle**: 21 bad bearer requests from same IP within 1 minute → 22nd returns 429 + Retry-After.
- **`iat` upper-age**: token with `iat = now - 25h` → 401 (older than 24h default).
- **Multi-aud without azp**: aud = `["a", "b"]`, no azp → 401.
- **Multi-aud with matching azp**: aud = `["api-aud", "other"]`, azp = clientID → 200.
- **Identifier with bidi-override**: sub contains U+202E → 401.
- **Identifier with comma**: sub = `"alice,bob"` → 401.
- **Identifier over 256 bytes** → 401.
- **`UserIdentifierClaim=email` at startup with EnableBearerAuth=true** → startup fails.
- **Excluded URL + bearer**: bearer header presented on excluded URL → request forwarded, downstream sees no `Authorization` header (stripped).
### 11.2 Unit tests (in `bearer_auth_test.go`)
- `classifyToken`: ID-token detection, access-token detection by `scope`/`scp`/`token_use`, ambiguous → reject.
- `resolveIdentifier`: precedence (`userIdentifierClaim``sub``client_id`/`azp`); missing → error; empty string → error.
- `sanitizeIdentifier`: rejects all `unicode.IsControl`; accepts email/sub-style values.
### 11.3 Introspection tests (`bearer_auth_introspection_test.go`)
- Token valid + introspection `active=true` → 200.
- Token valid + introspection `active=false` → 401.
- Introspection endpoint 500 → 503.
- Second request hits introspection cache (no second HTTP call).
### 11.4 Startup validation tests (extend `settings_test.go` / `main_test.go`)
- `EnableBearerAuth=true, Audience=""``New()` errors.
- `EnableBearerAuth=true, StrictAudienceValidation=false` → succeeds with warning.
- `EnableBearerAuth=false` → no validation; existing tests untouched.
### 11.5 Cookie-path regression suite
- All existing `TestServeHTTP_*` tests in `main_servehttp_test.go` pass unmodified.
- Add: cookie session, `EnableBearerAuth=true`, no bearer header → identical behaviour to baseline.
- Add: dirty session still triggers `Save()` after refactor.
### 11.6 Principal invariants
- `buildPrincipalFromSession`: `Source == sourceSession`; `IDToken` / `RefreshToken` populated when present in session.
- `buildPrincipalFromBearerToken`: `Source == sourceBearer`; `IDToken == ""`, `RefreshToken == ""`.
- `forwardAuthorized` produces identical headers for equivalent principals regardless of source.
### 11.7 Coverage gate
- New code in `bearer_auth.go` and `principal.go`: ≥ 90% line coverage.
- `forwardAuthorized` coverage ≥ existing `processAuthorizedRequest` coverage baseline.
### 11.8 Out of scope (follow-ups)
- Load test of bearer vs cookie hot path.
- Fuzzing the JWT parser.
- Additional auth methods (mTLS, API keys) — design enables them, but they are separate work.
## 12. Migration / Rollout
Default-off. Existing deployments observe no behavioural change. Operators opt in by setting:
```yaml
enableBearerAuth: true
audience: https://api.example.com # required when bearer enabled
# optional:
stripAuthorizationHeader: true # default
requireTokenIntrospection: false # default; set true for real-time revocation
userIdentifierClaim: client_id # optional override; defaults to sub fallback chain
```
Documentation: update `docs/CONFIGURATION.md` with a bearer-auth section, and add a new `docs/BEARER_AUTH.md` covering the security model, threat assumptions (token issuer is trusted; audience must be set; bearer means trust the issuer's revocation policy unless introspection enabled), and recommended configurations for common IdPs.
## 13. Security Considerations
| Concern | Mitigation |
|---|---|
| Token confusion (ID token used as bearer) | Reuse `detectTokenType` (`token_manager.go:187-303`) which checks `nonce`, `typ: at+jwt`, `token_use`, `scope`, aud-vs-clientID. Belt-and-braces: explicit `nonce` + `token_use == "id"` rejection on top. |
| Audience confusion (token for service B accepted by A) | `Audience` mandatory at startup; verified via existing `VerifyJWTSignatureAndClaims`; multi-aud tokens require matching `azp == clientID`. |
| Replay-via-blacklist false positive | `verifyOpts{skipReplayMarking: true}` on bearer path. Gates ONLY the Set; the Get stays so revoked tokens still fail. |
| Revocation lag | Optional RFC 7662 introspection. Bearer-path introspection cache TTL capped at 60s. Set `RequireTokenIntrospection=true` for real-time revocation. |
| `alg`-confusion / `alg=none` attacks | Hard-pin asymmetric allowlist at bearer entry, **before** JWKS fetch. Prevents wasted upstream calls and locks out HS/none probes. |
| `kid` injection / JWKS amplification | `kid` length cap (256 bytes) + charset allowlist enforced at bearer entry. |
| Bearer 401 brute-force / oracle | Per-IP `failedBearerAttempts` cache; configurable threshold + penalty box returning 429 + `Retry-After`. |
| `iat` clock-manipulation / forever-tokens | `MaxTokenAgeSeconds` upper bound (default 24h); cookie path unchanged. |
| Identifier-driven header injection | `sanitizeIdentifier`: length cap, control-char + bidi-override + `,;=` rejection. `net/http` rejects CRLF on the wire too (defence in depth). |
| Token leakage downstream | `StripAuthorizationHeader=true` by default. Also: `Authorization` stripped on excluded-URL requests so bearer can't leak into health/metrics downstream logs. |
| Token-in-logs | All log paths log reason categories, not raw tokens. Identifier hashed via SHA-256 truncated to 8 hex chars before any info/warn-level emission (full identifier only at debug). New `safeLogAuthEvent(category, hashedIdentifier, reasonCode)` helper makes this hard to misuse. |
| `email` claim spoofing | Startup fails if `EnableBearerAuth && UserIdentifierClaim == "email"`. Future human-user bearer iteration must add `email_verified` enforcement. |
| Bypass on SSE / WS endpoints | SSE/WS bypass keeps cookie-only behaviour; bearer ignored. Operators choose to widen if needed. |
| Mixed bearer + cookie precedence | Cookie wins by default (safer for browser scenarios); `BearerOverridesCookie=true` flips. WARN log on both-present requests. |
| Configuration drift (operator forgets audience) | Startup fails when `EnableBearerAuth=true && Audience==""`. |
| Downstream blast radius when `StripAuthorizationHeader=false` | Documented: forwarded bearer extends token's blast radius to all downstream services. Logs at those services become token stores. Operators must treat downstream log policy accordingly. |
| Introspection auth method (pre-existing gap, called out) | `token_introspection.go:80` uses `client_secret_basic` only; does not honour `private_key_jwt`. Out of scope for this PR but documented as a follow-up; operators using `ClientAuthMethod=private_key_jwt` + `RequireTokenIntrospection=true` should be aware introspection will use basic auth. |
## 14. Open Questions
None — all design decisions resolved during brainstorming + security review. Implementation may surface incidental questions (e.g. exact clock-skew leeway in `jwt.Verify`); those are out of scope for this spec and handled in the implementation plan.
## 14a. Security Review Reference
This design was reviewed by the `security-reviewer` subagent on 2026-05-18. Findings incorporated:
- **Critical**: C1 (classifier reuses `detectTokenType`), C2 (sub fallback dropped — unreachable due to `jwt.go:416`), C3 (replay-marking gates only Set, not Get; revocation regression test added).
- **High**: H1 (alg pinned at bearer entry), H2 (kid length + charset), H3 (cookie wins by default, configurable), H4 (per-IP 401 throttle), H5 (multi-aud requires azp).
- **Medium**: M1 (identifier max-length + bidi reject + delimiter chars), M2 (introspection cache TTL capped at 60s on bearer path), M4 (log-hashing via SHA-256[:8]), M5 (StripAuth blast-radius documented), M6 (iat upper-age bound), M7 (Authorization stripped on excluded URLs).
- **Low/Nit**: L2 (renamed to `BearerEmitWWWAuthenticate`), N3 (startup rejects `UserIdentifierClaim=email`).
- **Documented as pre-existing gaps (follow-up PRs)**: M3 (introspection auth method doesn't honour `private_key_jwt`).
## 15. Implementation Plan Reference
To be produced by the `writing-plans` skill in a follow-up document at `docs/superpowers/plans/2026-05-18-bearer-token-auth-plan.md`. The plan decomposes this design into ordered, independently-testable PRs.
+12 -12
View File
@@ -164,7 +164,7 @@ func (h *HybridBackend) Set(ctx context.Context, key string, value []byte, ttl t
// Check if we're in fallback mode
if h.fallbackMode.Load() {
h.logger.Debugf("Operating in fallback mode, skipping L2 write for key: %s", key)
h.logger.Debugf("Operating in fallback mode, skipping L2 write for key: %s", redactKey(key))
return nil // Don't fail the operation if L2 is down
}
@@ -176,13 +176,13 @@ func (h *HybridBackend) Set(ctx context.Context, key string, value []byte, ttl t
// Synchronous write for critical cache types
if err := h.secondary.Set(ctx, key, value, ttl); err != nil {
h.errors.Add(1)
h.logger.Warnf("Failed to write to L2 cache (sync) for key %s: %v", key, err)
h.logger.Warnf("Failed to write to L2 cache (sync) for key %s: %v", redactKey(key), err)
h.recordL2Error()
// Don't fail the operation - L1 write succeeded
return nil
}
h.l2Writes.Add(1)
h.logger.Debugf("Synchronous write to L2 completed for critical key: %s", key)
h.logger.Debugf("Synchronous write to L2 completed for critical key: %s", redactKey(key))
} else {
// Asynchronous write for non-critical cache types
select {
@@ -192,10 +192,10 @@ func (h *HybridBackend) Set(ctx context.Context, key string, value []byte, ttl t
ttl: ttl,
ctx: ctx,
}:
h.logger.Debugf("Queued async write to L2 for key: %s", key)
h.logger.Debugf("Queued async write to L2 for key: %s", redactKey(key))
default:
// Buffer is full, log and continue
h.logger.Warnf("Async write buffer full, dropping L2 write for key: %s", key)
h.logger.Warnf("Async write buffer full, dropping L2 write for key: %s", redactKey(key))
h.errors.Add(1)
}
}
@@ -209,7 +209,7 @@ func (h *HybridBackend) Get(ctx context.Context, key string) ([]byte, time.Durat
value, ttl, exists, err := h.primary.Get(ctx, key)
if err != nil {
h.errors.Add(1)
h.logger.Debugf("L1 get error for key %s: %v", key, err)
h.logger.Debugf("L1 get error for key %s: %v", redactKey(key), err)
}
if exists {
@@ -227,7 +227,7 @@ func (h *HybridBackend) Get(ctx context.Context, key string) ([]byte, time.Durat
value, ttl, exists, err = h.secondary.Get(ctx, key)
if err != nil {
h.errors.Add(1)
h.logger.Debugf("L2 get error for key %s: %v", key, err)
h.logger.Debugf("L2 get error for key %s: %v", redactKey(key), err)
h.recordL2Error()
h.misses.Add(1)
return nil, 0, false, nil // Don't propagate L2 errors
@@ -544,7 +544,7 @@ func (h *HybridBackend) queueL1Backfill(key string, value []byte, ttl time.Durat
case h.l1BackfillBuffer <- &l1BackfillItem{key: key, value: value, ttl: ttl}:
default:
h.l1BackfillDrops.Add(1)
h.logger.Debugf("L1 backfill buffer full, dropping for key: %s", key)
h.logger.Debugf("L1 backfill buffer full, dropping for key: %s", redactKey(key))
}
}
@@ -576,9 +576,9 @@ func (h *HybridBackend) l1BackfillWorker() {
}
writeCtx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
if err := h.primary.Set(writeCtx, item.key, item.value, item.ttl); err != nil {
h.logger.Debugf("Failed to populate L1 cache from L2 for key %s: %v", item.key, err)
h.logger.Debugf("Failed to populate L1 cache from L2 for key %s: %v", redactKey(item.key), err)
} else {
h.logger.Debugf("Populated L1 cache from L2 for key: %s", item.key)
h.logger.Debugf("Populated L1 cache from L2 for key: %s", redactKey(item.key))
}
cancel()
}
@@ -619,11 +619,11 @@ func (h *HybridBackend) asyncWriteWorker() {
writeCtx, cancel := context.WithTimeout(item.ctx, 500*time.Millisecond)
if err := h.secondary.Set(writeCtx, item.key, item.value, item.ttl); err != nil {
h.errors.Add(1)
h.logger.Debugf("Async write to L2 failed for key %s: %v", item.key, err)
h.logger.Debugf("Async write to L2 failed for key %s: %v", redactKey(item.key), err)
h.recordL2Error()
} else {
h.l2Writes.Add(1)
h.logger.Debugf("Async write to L2 completed for key: %s", item.key)
h.logger.Debugf("Async write to L2 completed for key: %s", redactKey(item.key))
}
cancel()
}
+26
View File
@@ -0,0 +1,26 @@
// Package backends provides cache backend implementations for the Traefik OIDC plugin.
package backends
import (
"crypto/sha256"
"encoding/hex"
)
// redactKey returns a short, deterministic hash prefix of a cache key for use
// in debug/info log lines. Cache keys in this plugin can include raw access /
// refresh / id tokens (any caller may pass an arbitrary string), and CodeQL
// flags `key=%s` formatters as a clear-text-logging sink for HTTP-header-
// sourced taint. The hash preserves cache-key uniqueness in logs (same key →
// same hash, useful for correlating a problematic key across log lines) while
// keeping the raw value out of disk-resident log streams.
//
// 8 hex chars (32 bits) is enough to disambiguate at human-debugging scale
// without making the hash itself a useful lookup primitive for an attacker
// who only has the log stream.
func redactKey(key string) string {
if key == "" {
return "(empty)"
}
sum := sha256.Sum256([]byte(key))
return hex.EncodeToString(sum[:4])
}
+2 -2
View File
@@ -190,7 +190,7 @@ func (c *Cache) Set(key string, value interface{}, ttl time.Duration) error {
c.currentSize++
atomic.AddInt64(&c.sets, 1)
c.logger.Debugf("Cache: Set key=%s, size=%d, ttl=%v", key, size, ttl)
c.logger.Debugf("Cache: Set key=%s, size=%d, ttl=%v", redactKey(key), size, ttl)
return nil
}
@@ -346,7 +346,7 @@ func (c *Cache) evictLRU() {
item, _ := elem.Value.(*Item) // Safe to ignore: type assertion from known type
c.removeItem(item.Key, item)
atomic.AddInt64(&c.evictions, 1)
c.logger.Debugf("Cache: Evicted LRU item key=%s", item.Key)
c.logger.Debugf("Cache: Evicted LRU item key=%s", redactKey(item.Key))
}
}
+22
View File
@@ -0,0 +1,22 @@
// Package cache provides the in-memory cache implementation for the Traefik
// OIDC plugin.
package cache
import (
"crypto/sha256"
"encoding/hex"
)
// redactKey returns a short, deterministic hash prefix of a cache key for use
// in debug/info log lines. Cache keys may include raw access / refresh / id
// tokens (callers pass arbitrary strings) and CodeQL flags `key=%s`
// formatters as a clear-text-logging sink for HTTP-header-sourced taint.
// The hash preserves uniqueness in logs (same key → same hash) while keeping
// the raw value out of disk-resident log streams.
func redactKey(key string) string {
if key == "" {
return "(empty)"
}
sum := sha256.Sum256([]byte(key))
return hex.EncodeToString(sum[:4])
}
+82 -17
View File
@@ -239,23 +239,63 @@ func NewWithContext(ctx context.Context, config *Config, next http.Handler, name
}
return 0
}(),
tokenCleanupStopChan: make(chan struct{}),
metadataRefreshStopChan: make(chan struct{}),
ctx: pluginCtx,
cancelFunc: cancelFunc,
suppressDiagnosticLogs: isTestMode(),
securityHeadersApplier: config.GetSecurityHeadersApplier(),
scopeFilter: NewScopeFilter(logger), // NEW - for discovery-based scope filtering
dcrConfig: config.DynamicClientRegistration,
allowPrivateIPAddresses: config.AllowPrivateIPAddresses,
minimalHeaders: config.MinimalHeaders,
stripAuthCookies: config.StripAuthCookies,
enableBackchannelLogout: config.EnableBackchannelLogout,
enableFrontchannelLogout: config.EnableFrontchannelLogout,
backchannelLogoutPath: normalizeLogoutPath(config.BackchannelLogoutURL),
frontchannelLogoutPath: normalizeLogoutPath(config.FrontchannelLogoutURL),
sessionInvalidationCache: cacheManager.GetSharedSessionInvalidationCache(),
refreshResultCache: cacheManager.GetSharedRefreshResultCache(),
tokenCleanupStopChan: make(chan struct{}),
metadataRefreshStopChan: make(chan struct{}),
ctx: pluginCtx,
cancelFunc: cancelFunc,
suppressDiagnosticLogs: isTestMode(),
securityHeadersApplier: config.GetSecurityHeadersApplier(),
scopeFilter: NewScopeFilter(logger), // NEW - for discovery-based scope filtering
dcrConfig: config.DynamicClientRegistration,
allowPrivateIPAddresses: config.AllowPrivateIPAddresses,
minimalHeaders: config.MinimalHeaders,
stripAuthCookies: config.StripAuthCookies,
enableBackchannelLogout: config.EnableBackchannelLogout,
enableFrontchannelLogout: config.EnableFrontchannelLogout,
backchannelLogoutPath: normalizeLogoutPath(config.BackchannelLogoutURL),
frontchannelLogoutPath: normalizeLogoutPath(config.FrontchannelLogoutURL),
sessionInvalidationCache: cacheManager.GetSharedSessionInvalidationCache(),
refreshResultCache: cacheManager.GetSharedRefreshResultCache(),
enableBearerAuth: config.EnableBearerAuth,
stripAuthorizationHeader: config.StripAuthorizationHeader,
bearerEmitWWWAuthenticate: config.BearerEmitWWWAuthenticate,
bearerOverridesCookie: config.BearerOverridesCookie,
bearerIdentifierClaim: func() string {
if config.BearerIdentifierClaim != "" {
return config.BearerIdentifierClaim
}
return "sub"
}(),
maxIdentifierLength: func() int {
if config.MaxIdentifierLength > 0 {
return config.MaxIdentifierLength
}
return 256
}(),
maxTokenAge: func() time.Duration {
if config.MaxTokenAgeSeconds > 0 {
return time.Duration(config.MaxTokenAgeSeconds) * time.Second
}
return 24 * time.Hour
}(),
bearerFailureThreshold: func() int {
if config.BearerFailureThreshold > 0 {
return config.BearerFailureThreshold
}
return 20
}(),
bearerFailureWindow: func() time.Duration {
if config.BearerFailureWindowSeconds > 0 {
return time.Duration(config.BearerFailureWindowSeconds) * time.Second
}
return 60 * time.Second
}(),
bearerFailurePenalty: func() time.Duration {
if config.BearerFailurePenaltySeconds > 0 {
return time.Duration(config.BearerFailurePenaltySeconds) * time.Second
}
return 60 * time.Second
}(),
}
// Log audience configuration
@@ -265,6 +305,31 @@ func NewWithContext(ctx context.Context, config *Config, next http.Handler, name
t.logger.Debugf("No custom audience specified, using clientID as audience: %s", t.clientID)
}
// Bearer-auth startup validation. The bearer path is M2M-only and demands
// a non-default audience so tokens issued for a different resource cannot
// be replayed against this service. The BearerIdentifierClaim guard blocks
// the `email` claim explicitly — without email_verified enforcement (out of
// scope for M2M), trusting email is a spoofing vector for federated IdPs.
// See spec §7.9 / §13.
if config.EnableBearerAuth {
if config.Audience == "" {
cancelFunc()
return nil, fmt.Errorf("EnableBearerAuth=true requires Audience to be set explicitly (cannot default to clientID — that path accepts ID tokens)")
}
if t.bearerIdentifierClaim == "email" {
cancelFunc()
return nil, fmt.Errorf("enableBearerAuth=true with bearerIdentifierClaim=%q is rejected: email-based identity without email_verified enforcement is a spoofing vector for federated IdPs (use \"sub\" or a custom claim; cookie-path userIdentifierClaim is unaffected)", t.bearerIdentifierClaim)
}
if !config.StrictAudienceValidation {
t.logger.Infof("EnableBearerAuth=true with StrictAudienceValidation=false: recommend enabling strict audience validation for hardening")
}
t.bearerFailureTracker = newBearerFailureTracker(
t.bearerFailureThreshold, t.bearerFailureWindow, t.bearerFailurePenalty,
)
t.logger.Infof("Bearer-token auth enabled: audience=%q identifierClaim=%q stripAuthz=%t bearerOverridesCookie=%t maxTokenAge=%s",
config.Audience, t.bearerIdentifierClaim, t.stripAuthorizationHeader, t.bearerOverridesCookie, t.maxTokenAge)
}
// Convert sessionMaxAge from seconds to duration (0 will use default 24 hours)
sessionMaxAge := time.Duration(config.SessionMaxAge) * time.Second
t.sessionManager, _ = NewSessionManager(config.SessionEncryptionKey, config.ForceHTTPS, config.CookieDomain, config.CookiePrefix, sessionMaxAge, t.logger) // Safe to ignore: session manager creation with fallback to defaults
+137 -56
View File
@@ -168,6 +168,14 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
// unauthenticated traffic would silently expose the backend.
if bypass, reason := t.shouldBypassAuth(req); bypass {
t.logger.Debugf("Bypassing OIDC for %s (%s)", req.URL.Path, reason)
// When bearer auth is enabled, strip the Authorization header on
// bypassed paths so a bearer token can't leak into health/metrics/
// public endpoint logs via downstream services that don't expect it.
// Excluded URLs are explicitly public; bearer is an artifact of the
// API auth flow that doesn't belong on them.
if t.enableBearerAuth {
req.Header.Del("Authorization")
}
switch reason {
case bypassReasonExcluded:
// Operator-declared excluded URLs forward unconditionally.
@@ -236,6 +244,24 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
// Bypass checks already ran before the init wait; no need to repeat them.
t.sessionManager.CleanupOldCookies(rw, req)
// Bearer-token auth (opt-in). Runs after init (we need issuer+JWKs+aud
// available) and after bypass (excluded URLs always win). Cookie-vs-
// bearer precedence is configurable; the safe default is cookie-wins.
// See bearer_auth.go for the full pipeline.
if t.enableBearerAuth {
if _, hasBearer := detectBearerToken(req); hasBearer {
cookiePresent := t.hasSessionCookie(req)
if !cookiePresent || t.bearerOverridesCookie {
if cookiePresent {
t.logger.Infof("Both Authorization: Bearer and session cookie present on %s; bearer-wins per BearerOverridesCookie=true", req.URL.Path)
}
t.handleBearerRequest(rw, req)
return
}
t.logger.Infof("Both Authorization: Bearer and session cookie present on %s; cookie-wins (default); bearer ignored", req.URL.Path)
}
}
session, err := t.sessionManager.GetSession(req)
if err != nil {
t.logger.Errorf("Error getting session: %v. Initiating authentication.", err)
@@ -401,10 +427,17 @@ func (t *TraefikOidc) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
t.defaultInitiateAuthentication(rw, req, session, redirectURL)
}
// processAuthorizedRequest processes requests for authenticated users.
// It extracts claims, validates roles/groups if configured, sets authentication headers,
// processes header templates, and forwards the request to the next handler.
// Domain checks should be performed before calling this method.
// processAuthorizedRequest processes requests for authenticated cookie/session
// users. It performs session-specific checks (identifier presence, backchannel-
// logout invalidation, claims extraction with potential re-auth), persists
// dirty session state, then delegates the post-auth pipeline (roles/groups,
// header injection, security headers, cookie strip, forward) to
// forwardAuthorized.
//
// The bearer-token path uses the same forwardAuthorized helper but takes a
// different route to it (see bearer_auth.go). Keeping forwardAuthorized
// session-agnostic is what lets the two auth methods share one pipeline.
//
// Parameters:
// - rw: The HTTP response writer.
// - req: The HTTP request to process.
@@ -442,8 +475,7 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
// the parsed claims keyed on the raw ID token, so concurrent dashboard
// panel requests on the same session don't repeatedly base64-decode and
// JSON-unmarshal the same JWT (a real cost under the yaegi interpreter
// that hosts Traefik plugins). idClaims is reused below by the
// header-templates branch.
// that hosts Traefik plugins).
idToken := session.GetIDToken()
var (
idClaims map[string]interface{}
@@ -472,18 +504,76 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
return
}
var groups, roles []string
if groupClaimsErr != nil && len(t.allowedRolesAndGroups) > 0 {
// Claims couldn't be extracted but roles checks are required:
// re-authenticate rather than 403 (session may be salvageable on
// re-issue). Bearer path uses 401 for the equivalent failure.
t.logger.Errorf("Failed to extract claims for roles/groups check: %v", groupClaimsErr)
session.ResetRedirectCount()
t.defaultInitiateAuthentication(rw, req, session, redirectURL)
return
}
if groupClaimsErr == nil && groupClaims != nil {
var err error
groups, roles, err = t.extractGroupsAndRolesFromClaims(groupClaims)
if err != nil && len(t.allowedRolesAndGroups) > 0 {
t.logger.Errorf("Failed to extract groups and roles: %v", err)
session.ResetRedirectCount()
t.defaultInitiateAuthentication(rw, req, session, redirectURL)
// Persist any dirty session state BEFORE forwardAuthorized writes the
// response. Once next.ServeHTTP fires, Set-Cookie can no longer reach
// the client. The forwardAuthorized pipeline does not mutate session
// state, so saving here is safe.
if session.IsDirty() {
if err := session.Save(req, rw); err != nil {
t.logger.Errorf("Failed to save session after processing headers: %v", err)
}
} else {
t.logger.Debug("Session not dirty, skipping save in processAuthorizedRequest")
}
// Build the source-agnostic principal. ID-token claims drive header
// templates and roles when present; otherwise fall back to access-token
// claims (matches prior behavior for opaque-ID-token providers).
p := &principal{
Source: sourceSession,
Identifier: userIdentifier,
AccessToken: session.GetAccessToken(),
IDToken: idToken,
RefreshToken: session.GetRefreshToken(),
Claims: groupClaims,
}
t.forwardAuthorized(rw, req, p)
}
// forwardAuthorized completes the post-authentication pipeline shared by the
// cookie/session path and the bearer-token path. It performs:
//
// 1. Roles/groups extraction from p.Claims (idempotent; existing
// extractGroupsAndRolesFromClaims helper).
// 2. allowedRolesAndGroups gate — writes a 403 and returns if denied.
// 3. Identity-header injection (X-Forwarded-User, X-User-Groups, X-User-Roles,
// plus X-Auth-Request-* when !minimalHeaders).
// 4. Operator-defined header templates.
// 5. Security headers (delegated to t.securityHeadersApplier or fallback).
// 6. OIDC session-cookie strip (stripAuthCookies).
// 7. Authorization header strip on bearer source when stripAuthorizationHeader.
// 8. next.ServeHTTP.
//
// Session persistence is the CALLER's responsibility — it must happen before
// this function so Set-Cookie reaches the response.
func (t *TraefikOidc) forwardAuthorized(rw http.ResponseWriter, req *http.Request, p *principal) {
var (
groups, roles []string
extractErr error
)
if p.Claims != nil {
groups, roles, extractErr = t.extractGroupsAndRolesFromClaims(p.Claims)
if extractErr != nil && len(t.allowedRolesAndGroups) > 0 {
// Bearer path: 403 (caller already verified the token; principal
// claims are present but malformed for roles purposes).
// Cookie path can't reach here because processAuthorizedRequest
// catches groupClaimsErr earlier.
t.logger.Errorf("Failed to extract groups and roles: %v", extractErr)
t.sendErrorResponse(rw, req, "Access denied", http.StatusForbidden)
return
}
if err == nil {
if extractErr == nil {
if len(groups) > 0 {
req.Header.Set("X-User-Groups", strings.Join(groups, ","))
}
@@ -502,62 +592,46 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
}
}
if !allowed {
t.logger.Infof("User %s does not have any allowed roles or groups", userIdentifier)
t.logger.Infof("User %s does not have any allowed roles or groups", p.Identifier)
errorMsg := fmt.Sprintf("Access denied: You do not have any of the allowed roles or groups. To log out, visit: %s", t.logoutURLPath)
t.sendErrorResponse(rw, req, errorMsg, http.StatusForbidden)
return
}
}
req.Header.Set("X-Forwarded-User", userIdentifier)
req.Header.Set("X-Forwarded-User", p.Identifier)
// When minimalHeaders is enabled, skip extra headers to prevent 431 errors
if !t.minimalHeaders {
req.Header.Set("X-Auth-Request-Redirect", req.URL.RequestURI())
req.Header.Set("X-Auth-Request-User", userIdentifier)
if idToken != "" {
req.Header.Set("X-Auth-Request-Token", idToken)
req.Header.Set("X-Auth-Request-User", p.Identifier)
if p.IDToken != "" {
req.Header.Set("X-Auth-Request-Token", p.IDToken)
}
}
if len(t.headerTemplates) > 0 {
if idClaimsErr != nil {
t.logger.Errorf("Failed to extract claims from ID Token for template headers: %v", idClaimsErr)
} else {
// idClaims may be nil when no ID token is present; templates
// referencing .Claims.* will simply produce empty values, which
// matches the prior behavior.
templateData := map[string]interface{}{
"AccessToken": session.GetAccessToken(),
"IDToken": idToken,
"RefreshToken": session.GetRefreshToken(),
"Claims": idClaims,
}
for headerName, tmpl := range t.headerTemplates {
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)
continue
}
headerValue := buf.String()
req.Header.Set(headerName, headerValue)
t.logger.Debugf("Set templated header %s = %s", headerName, headerValue)
}
// NOTE: templates only mutate request headers (not session state),
// so we deliberately do NOT MarkDirty / Save here. Previously every
// authenticated request with header templates re-encrypted and
// rewrote all session cookies, which was a measurable CPU and
// Set-Cookie tax on dashboards that poll many panels per second.
// p.Claims may be nil (e.g. session without an ID token). Templates
// referencing .Claims.* will simply produce empty values — matches
// the prior behavior. Bearer-source principals always carry access-
// token claims (post-verifyToken).
templateData := map[string]interface{}{
"AccessToken": p.AccessToken,
"IDToken": p.IDToken,
"RefreshToken": p.RefreshToken,
"Claims": p.Claims,
}
}
if session.IsDirty() {
if err := session.Save(req, rw); err != nil {
t.logger.Errorf("Failed to save session after processing headers: %v", err)
for headerName, tmpl := range t.headerTemplates {
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)
continue
}
headerValue := buf.String()
req.Header.Set(headerName, headerValue)
t.logger.Debugf("Set templated header %s = %s", headerName, headerValue)
}
} else {
t.logger.Debug("Session not dirty, skipping save in processAuthorizedRequest")
}
// Apply security headers if configured
@@ -573,7 +647,7 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
// Strip OIDC session cookies before forwarding to the backend to prevent
// HTTP 431 "Request Header Fields Too Large" errors (GitHub issue #122).
if t.stripAuthCookies {
if t.stripAuthCookies && t.sessionManager != nil {
prefix := t.sessionManager.GetCookiePrefix()
filtered := make([]*http.Cookie, 0, len(req.Cookies()))
for _, c := range req.Cookies() {
@@ -587,7 +661,14 @@ func (t *TraefikOidc) processAuthorizedRequest(rw http.ResponseWriter, req *http
}
}
t.logger.Debugf("Request authorized for user %s, forwarding to next handler", userIdentifier)
// Bearer source: strip the Authorization header to keep the raw token
// out of downstream service logs. Off-by-config for operators who chain
// services that each re-verify the bearer.
if p.Source == sourceBearer && t.stripAuthorizationHeader {
req.Header.Del("Authorization")
}
t.logger.Debugf("Request authorized for user %s (source=%d), forwarding to next handler", p.Identifier, p.Source)
t.next.ServeHTTP(rw, req)
}
+58
View File
@@ -0,0 +1,58 @@
// Package traefikoidc — principal abstraction for the shared post-auth
// pipeline. A principal carries the resolved identity + tokens + claims
// produced by EITHER the cookie session path or the bearer-token path, so
// downstream header injection / roles checks / forwarding can be implemented
// once and reused.
package traefikoidc
// principalSource indicates which auth path produced a principal. Used by
// forwardAuthorized to decide source-specific behavior (e.g. only strip the
// Authorization header for bearer-source principals).
type principalSource int
const (
sourceSession principalSource = iota
sourceBearer
)
// principal is the immutable post-auth value passed to forwardAuthorized.
// No methods mutate it; no manager pointer; no I/O. Pure data.
type principal struct {
Claims map[string]interface{}
Identifier string
Subject string
ClientID string
AccessToken string
IDToken string
RefreshToken string
Source principalSource
}
// buildPrincipalFromSession adapts an authenticated SessionData into a
// principal value WITHOUT writing back to the session. This is the only
// function that still knows about SessionData; the rest of the pipeline is
// session-agnostic. Returns nil when the session has no usable identity.
func (t *TraefikOidc) buildPrincipalFromSession(session *SessionData) *principal {
if session == nil {
return nil
}
identifier := session.GetUserIdentifier()
if identifier == "" {
return nil
}
var claims map[string]interface{}
if idToken := session.GetIDToken(); idToken != "" && t.extractClaimsFunc != nil {
// Best-effort: cached on the session, never blocking.
claims, _ = session.GetIDTokenClaims(t.extractClaimsFunc) // Safe to ignore: claims-error path handled by header-template branch
}
return &principal{
Source: sourceSession,
Identifier: identifier,
AccessToken: session.GetAccessToken(),
IDToken: session.GetIDToken(),
RefreshToken: session.GetRefreshToken(),
Claims: claims,
}
}
+76 -17
View File
@@ -63,23 +63,23 @@ type Config struct {
// IdPs do not expose RT TTL on the wire, so this is intentionally a
// conservative heuristic; tune to match your provider configuration.
// Default 21600 (6h). Set to 0 to disable the check.
MaxRefreshTokenAgeSeconds int `json:"maxRefreshTokenAgeSeconds"`
SessionMaxAge int `json:"sessionMaxAge"`
RateLimit int `json:"rateLimit"`
OverrideScopes bool `json:"overrideScopes"`
DisableReplayDetection bool `json:"disableReplayDetection,omitempty"`
RequireTokenIntrospection bool `json:"requireTokenIntrospection,omitempty"`
AllowOpaqueTokens bool `json:"allowOpaqueTokens,omitempty"`
StrictAudienceValidation bool `json:"strictAudienceValidation,omitempty"`
EnablePKCE bool `json:"enablePKCE"`
ForceHTTPS bool `json:"forceHTTPS"`
AllowPrivateIPAddresses bool `json:"allowPrivateIPAddresses,omitempty"`
MinimalHeaders bool `json:"minimalHeaders,omitempty"`
StripAuthCookies bool `json:"stripAuthCookies,omitempty"`
EnableBackchannelLogout bool `json:"enableBackchannelLogout,omitempty"`
EnableFrontchannelLogout bool `json:"enableFrontchannelLogout,omitempty"`
BackchannelLogoutURL string `json:"backchannelLogoutURL,omitempty"`
FrontchannelLogoutURL string `json:"frontchannelLogoutURL,omitempty"`
MaxRefreshTokenAgeSeconds int `json:"maxRefreshTokenAgeSeconds"`
SessionMaxAge int `json:"sessionMaxAge"`
RateLimit int `json:"rateLimit"`
OverrideScopes bool `json:"overrideScopes"`
DisableReplayDetection bool `json:"disableReplayDetection,omitempty"`
RequireTokenIntrospection bool `json:"requireTokenIntrospection,omitempty"`
AllowOpaqueTokens bool `json:"allowOpaqueTokens,omitempty"`
StrictAudienceValidation bool `json:"strictAudienceValidation,omitempty"`
EnablePKCE bool `json:"enablePKCE"`
ForceHTTPS bool `json:"forceHTTPS"`
AllowPrivateIPAddresses bool `json:"allowPrivateIPAddresses,omitempty"`
MinimalHeaders bool `json:"minimalHeaders,omitempty"`
StripAuthCookies bool `json:"stripAuthCookies,omitempty"`
EnableBackchannelLogout bool `json:"enableBackchannelLogout,omitempty"`
EnableFrontchannelLogout bool `json:"enableFrontchannelLogout,omitempty"`
BackchannelLogoutURL string `json:"backchannelLogoutURL,omitempty"`
FrontchannelLogoutURL string `json:"frontchannelLogoutURL,omitempty"`
// CACertPath is an optional filesystem path to a PEM-encoded CA bundle used
// to verify the OIDC provider's TLS certificate. Use this when the provider
// is signed by an internal/private CA that is not in the system trust store.
@@ -125,6 +125,52 @@ type Config struct {
// ClientAssertionAlg is the JWS signing algorithm. Defaults to RS256.
// Supported: RS256/384/512, PS256/384/512, ES256/384/512.
ClientAssertionAlg string `json:"clientAssertionAlg,omitempty"`
// --- Bearer-token auth (opt-in M2M path) ---
// EnableBearerAuth turns on the Authorization: Bearer <jwt> auth path.
// Default false. When true, Audience MUST be set or startup fails. The
// bearer path is M2M-only: it accepts validated access-token JWTs, rejects
// ID tokens, and forwards principal headers downstream without creating a
// cookie session. See docs/BEARER_AUTH.md for the threat model.
EnableBearerAuth bool `json:"enableBearerAuth,omitempty"`
// BearerIdentifierClaim names the JWT claim used as the principal identifier
// on the bearer-token auth path. Default "sub". Decoupled from
// UserIdentifierClaim (which defaults to "email" and drives the cookie path)
// so M2M bearer flow never accidentally relies on an unverified email.
BearerIdentifierClaim string `json:"bearerIdentifierClaim,omitempty"`
// StripAuthorizationHeader removes the Authorization header from the
// forwarded request after successful bearer auth, so downstream services
// never see the raw token. Default true. Disable only when a downstream
// explicitly needs to re-validate the bearer.
StripAuthorizationHeader bool `json:"stripAuthorizationHeader,omitempty"`
// BearerEmitWWWAuthenticate controls whether 401 responses on the bearer
// path include a WWW-Authenticate: Bearer error="invalid_token" hint per
// RFC 6750 §3. Default true. Disable to reduce reconnaissance signal.
BearerEmitWWWAuthenticate bool `json:"bearerEmitWWWAuthenticate,omitempty"`
// BearerOverridesCookie controls precedence when both Authorization:
// Bearer and a session cookie are present. Default false: cookie wins
// (safer against browser/extension/proxy bearer injection). Set true for
// the bearer-wins convention used by AWS/GCP/Kubernetes API gateways.
BearerOverridesCookie bool `json:"bearerOverridesCookie,omitempty"`
// MaxTokenAgeSeconds caps how old (iat-based) a bearer token may be.
// Default 86400 (24h). Bounds clock-manipulation tokens with implausibly
// distant iat values.
MaxTokenAgeSeconds int64 `json:"maxTokenAgeSeconds,omitempty"`
// MaxIdentifierLength bounds the post-sanitisation length of the bearer
// principal identifier (the value injected as X-Forwarded-User). Default
// 256.
MaxIdentifierLength int `json:"maxIdentifierLength,omitempty"`
// BearerFailureThreshold is the number of consecutive 401s from one
// source IP within BearerFailureWindowSeconds that trips the throttle.
// Default 20.
BearerFailureThreshold int `json:"bearerFailureThreshold,omitempty"`
// BearerFailureWindowSeconds is the rolling window (seconds) over which
// 401s are counted for throttling. Default 60.
BearerFailureWindowSeconds int `json:"bearerFailureWindowSeconds,omitempty"`
// BearerFailurePenaltySeconds is how long an IP is parked in the 429
// penalty box after BearerFailureThreshold is exceeded. Default 60.
BearerFailurePenaltySeconds int `json:"bearerFailurePenaltySeconds,omitempty"`
}
// loadCACertPool assembles an x509.CertPool from CACertPath and CACertPEM.
@@ -291,6 +337,19 @@ func CreateConfig() *Config {
MaxRefreshTokenAgeSeconds: 21600, // 6h - conservative heuristic, see field doc
SecurityHeaders: createDefaultSecurityConfig(),
Redis: nil, // Redis is disabled by default, configure via Traefik or env vars
// Bearer-auth defaults. EnableBearerAuth=false leaves the feature
// dormant; the rest are values that apply only when bearer is enabled.
EnableBearerAuth: false,
BearerIdentifierClaim: "sub",
StripAuthorizationHeader: true,
BearerEmitWWWAuthenticate: true,
BearerOverridesCookie: false,
MaxTokenAgeSeconds: 86400,
MaxIdentifierLength: 256,
BearerFailureThreshold: 20,
BearerFailureWindowSeconds: 60,
BearerFailurePenaltySeconds: 60,
}
return c
+32 -3
View File
@@ -29,6 +29,29 @@ import (
//
//nolint:gocognit,gocyclo // Complex token verification logic requires multiple security checks
func (t *TraefikOidc) VerifyToken(token string) error {
return t.verifyTokenWithOpts(token, verifyOpts{})
}
// verifyOpts are internal-only knobs for verifyTokenWithOpts. Kept unexported
// because they expose subtle replay-protection semantics that are dangerous
// to misuse.
type verifyOpts struct {
// skipReplayMarking suppresses the JTI -> blacklist Set near the bottom
// of verifyTokenWithOpts. The Get at the top remains active, so revoked
// tokens (added to the blacklist by RevokeToken) are still rejected.
// Used exclusively by the bearer-auth path, where bearer tokens are
// designed to be reused until exp.
skipReplayMarking bool
}
// verifyTokenWithOpts runs the full token verification pipeline used by both
// the cookie path and the bearer path. The cookie path uses the zero-value
// opts; the bearer path sets skipReplayMarking=true. See the security spec
// (docs/superpowers/specs/2026-05-18-bearer-token-auth-design.md §7.7) for
// the exact contract: skipReplayMarking gates ONLY the JTI Set, never the Get.
//
//nolint:gocognit,gocyclo // Complex token verification logic requires multiple security checks
func (t *TraefikOidc) verifyTokenWithOpts(token string, opts verifyOpts) error {
if token == "" {
return fmt.Errorf("invalid JWT format: token is empty")
}
@@ -76,7 +99,9 @@ func (t *TraefikOidc) VerifyToken(token string) error {
}
// Only check JTI blacklist for tokens that aren't already in the cache
// This is for FIRST-TIME validation to detect replay attacks
// This is for FIRST-TIME validation to detect replay attacks. The
// blacklist Get is ALWAYS active on the bearer path too — only the
// Set below is gated by opts.skipReplayMarking.
if jti, ok := parsedJWT.Claims["jti"].(string); ok && jti != "" {
// Skip JTI blacklist check if replay detection is disabled
if !t.disableReplayDetection {
@@ -105,8 +130,12 @@ func (t *TraefikOidc) VerifyToken(token string) error {
t.cacheVerifiedToken(token, jwt.Claims)
if jti, ok := jwt.Claims["jti"].(string); ok && jti != "" && !t.disableReplayDetection {
// Only add to blacklist if replay detection is enabled
// Replay marking: add JTI to blacklist so subsequent presentations of
// the SAME token can short-circuit via cache. Bearer path suppresses
// this Set (opts.skipReplayMarking=true) because bearer tokens are
// designed for reuse until exp; the cache-evict-then-replay scenario
// would otherwise trigger false replay detection.
if jti, ok := jwt.Claims["jti"].(string); ok && jti != "" && !t.disableReplayDetection && !opts.skipReplayMarking {
expiry := time.Now().Add(defaultBlacklistDuration)
if expClaim, expOk := jwt.Claims["exp"].(float64); expOk {
expTime := time.Unix(int64(expClaim), 0)
+13
View File
@@ -149,4 +149,17 @@ type TraefikOidc struct {
enablePKCE bool
forceHTTPS bool
suppressDiagnosticLogs bool
// Bearer-auth runtime state (populated only when EnableBearerAuth=true).
bearerIdentifierClaim string
bearerFailureTracker *bearerFailureTracker
maxTokenAge time.Duration
maxIdentifierLength int
bearerFailureThreshold int
bearerFailureWindow time.Duration
bearerFailurePenalty time.Duration
enableBearerAuth bool
stripAuthorizationHeader bool
bearerEmitWWWAuthenticate bool
bearerOverridesCookie bool
}