feat(07-01): add JWT mint, refresh, and blacklist primitives

Co-authored-by: Cursor <cursoragent@cursor.com>

bouncer/mint.go

@@ -0,0 +1,57 @@
+package bouncer
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+// prvHash is sha1("Golem15\User\Models\User"), the lock-subject PHP jwt-auth
+// stamps on every user token.
+const prvHash = "a867434cbc213adfbe78a02bed7082a6bd99c883"
+
+type registeredClaims struct {
+	jwt.RegisteredClaims
+	Prv string `json:"prv,omitempty"`
+}
+
+// Mint signs an HS256 token whose iss is the full URL of the minting endpoint.
+// The returned jti is the token's own jti claim.
+func Mint(secret, sub, issuerURL string, ttl time.Duration) (string, string, error) {
+	if strings.TrimSpace(secret) == "" {
+		return "", "", fmt.Errorf("bouncer: jwt secret is empty")
+	}
+	jti, err := newJTI()
+	if err != nil {
+		return "", "", err
+	}
+	now := time.Now()
+	claims := registeredClaims{
+		RegisteredClaims: jwt.RegisteredClaims{
+			Issuer:    issuerURL,
+			Subject:   sub,
+			ExpiresAt: jwt.NewNumericDate(now.Add(ttl)),
+			NotBefore: jwt.NewNumericDate(now),
+			IssuedAt:  jwt.NewNumericDate(now),
+			ID:        jti,
+		},
+		Prv: prvHash,
+	}
+	signed, err := jwt.NewWithClaims(jwt.SigningMethodHS256, claims).SignedString([]byte(secret))
+	if err != nil {
+		return "", "", err
+	}
+	return signed, jti, nil
+}
+
+func newJTI() (string, error) {
+	buf := make([]byte, 16)
+	if _, err := rand.Read(buf); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(buf), nil
+}