Rene Nochebuena a9c9f3434e feat(auth-jwt): initial implementation — JWT lifecycle and AuthMiddleware (v1.0.0)
Introduces code.nochebuena.dev/einherjar/auth-jwt — JWT authentication middleware
and token lifecycle management for the Einherjar framework. Absorbs httpauth-jwt
from micro-lib with three changes: logger parameter on AuthMiddleware, httputil.Error
for consistent 401 responses, and added ECDSA support.

Signers and Verifiers (one file per implementation — CT-6 compliant):
- Verifier interface — Verify(tokenString string) (*jwt.Token, error)
- Signer interface — extends Verifier; adds Sign(claims jwt.Claims) (string, error)
- signer_hmac.go — NewHMACSigner(secret) → HS256; jwt.WithJSONNumber() on Verify
- signer_rsa.go — NewRSASigner(key) + NewRSASignerFromPEM(pem) → RS256
- verifier_rsa.go — NewRSAPublicKeyVerifier + NewRSAPublicKeyVerifierFromPEM → RS256 verify-only
- signer_ec.go — NewECSigner(key) + NewECSignerFromPEM(pem) → ES256/384/512; algorithm
  auto-detected from key curve (P-256→ES256, P-384→ES384, P-521→ES512)
- verifier_ec.go — NewECPublicKeyVerifier + NewECPublicKeyVerifierFromPEM → EC verify-only

Token lifecycle:
- TokenConfig struct — AccessTTL, RefreshTTL, Issuer
- TokenPair struct — AccessToken, RefreshToken, ExpiresIn
- IssueTokenPair — access + refresh pair; customClaims merged at top level; refresh
  carries only sub/iss/iat/exp/jti/fam; jwt.WithJSONNumber() preserves int64 bitmasks
- Blacklist interface — IsRevoked + Revoke; satisfied by cache-valkey via duck typing
- ErrTokenRevoked — errors.New sentinel; errors.Is pattern for replay-attack detection
- RefreshTokenPair — verifies token, checks blacklist, revokes old JTI, issues new pair

HTTP middleware:
- AuthMiddleware(logger, verifier, publicPaths) — verifies Bearer tokens; calls
  authmw.SetTokenData on success; 401 routed through httputil.Error (Warn level);
  publicPaths use path.Match wildcards; accepts Verifier (not Signer) to enforce
  narrowest-interface principle for verify-only services

Compliance test (package authjwt_test) enforces CT-6 (≤1 exported TypeSpec/file),
compile-time interface satisfaction, and behavioural coverage: HMAC/RSA/EC sign+verify,
algorithm mismatch rejection, IssueTokenPair claims/jti/fam, RefreshTokenPair success/
revoked/blacklist-error/custom-claims, MaxInt64 json.Number precision, AuthMiddleware
valid/invalid/expired/missing/public-path/wildcard/JSON-body/RSA-verifier/SetTokenData.

Depends on auth v1.0.0, contracts v1.0.0, core v1.0.0, web v1.0.0, jwt/v5 v5.2.1.

- identifiable.go: package-level Module variable (observability.Identifiable) for version
  identification — auth-jwt is a function library; not registered with the launcher
2026-05-29 16:13:01 +00:00

einherjar/auth-jwt

version license go

A warrior's seal is recognized anywhere — but only if it cannot be forged.

JWT authentication middleware and token lifecycle management for the Einherjar framework. Supports HMAC-SHA256 (HS256), RSA-SHA256 (RS256), and ECDSA (ES256/ES384/ES512).

API

Symbol Kind Description
Verifier interface Validates JWT strings
Signer interface Extends Verifier; also signs tokens
NewHMACSigner(secret) func HS256 signer
NewRSASigner(key) func RS256 signer
NewRSASignerFromPEM(pem) func RS256 signer from PKCS#8/PKCS#1 PEM
NewRSAPublicKeyVerifier(key) func RS256 verifier (verify-only)
NewRSAPublicKeyVerifierFromPEM(pem) func RS256 verifier from PKIX/PKCS#1 PEM
NewECSigner(key) func ES256/384/512 signer (curve auto-detected)
NewECSignerFromPEM(pem) func EC signer from PKCS#8 PEM
NewECPublicKeyVerifier(key) func EC verifier (verify-only)
NewECPublicKeyVerifierFromPEM(pem) func EC verifier from PKIX PEM
TokenConfig struct AccessTTL, RefreshTTL, Issuer
TokenPair struct AccessToken, RefreshToken, ExpiresIn
IssueTokenPair(signer, uid, claims, cfg) func Sign access + refresh pair
Blacklist interface JTI revocation store (duck-typed by cache-valkey)
ErrTokenRevoked var Sentinel for replay-attack detection
RefreshTokenPair(ctx, signer, token, bl, cfg, claims) func Rotate tokens with blacklist check
AuthMiddleware(logger, verifier, publicPaths) func HTTP middleware — verifies Bearer token, calls authmw.SetTokenData

Dependency graph

contracts/logging  ──► auth-jwt
contracts/security ──► auth-jwt  (via auth/authmw)
core/xerrors       ──► auth-jwt
web/httputil       ──► auth-jwt
auth/authmw        ──► auth-jwt
jwt/v5             ──► auth-jwt  (only external dependency)

Wiring example — HMAC, full stack

import (
    "code.nochebuena.dev/einherjar/auth-jwt"
    "code.nochebuena.dev/einherjar/auth/authmw"
    "code.nochebuena.dev/einherjar/auth/rbac"
)

signer := authjwt.NewHMACSigner([]byte(os.Getenv("JWT_SECRET")))
cfg := authjwt.TokenConfig{
    AccessTTL:  15 * time.Minute,
    RefreshTTL: 7 * 24 * time.Hour,
    Issuer:     "myapp",
}

// JWT verification runs first (global).
srv.Use(authjwt.AuthMiddleware(logger, signer, []string{"/health", "/auth/*"}))

// Enrichment and authz follow.
srv.Use(authmw.EnrichmentMiddleware(logger, userEnricher))

const ReadOrders = security.Permission(0)
srv.With(authmw.AuthzMiddleware(logger, permissions, "orders", ReadOrders)).
    Get("/orders", ordersHandler)

// Login handler issues tokens:
pair, err := authjwt.IssueTokenPair(signer, uid, customClaims, cfg)

// Refresh handler rotates tokens:
newPair, err := authjwt.RefreshTokenPair(ctx, signer, body.RefreshToken, blacklist, cfg, freshClaims)
if errors.Is(err, authjwt.ErrTokenRevoked) {
    // replay attack — return 401 and require re-login
}

Verifier-only microservice (RSA)

// Service that verifies tokens but never issues them.
verifier, err := authjwt.NewRSAPublicKeyVerifierFromPEM([]byte(os.Getenv("RSA_PUBLIC_KEY_PEM")))
srv.Use(authjwt.AuthMiddleware(logger, verifier, publicPaths))

Environment variables

None. All configuration is passed in code.

Install

go get code.nochebuena.dev/einherjar/auth-jwt@v1.0.0
Description
JWT signing, verification, and token pair lifecycle with HMAC, RSA, and EC support
Readme 68 KiB
2026-05-29 10:13:27 -06:00
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