first commit

backend/internal/infrastructure/auth/jwt.go

@@ -0,0 +1,145 @@
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+// JWTManager handles JWT token creation and verification
+type JWTManager struct {
+	secretKey string
+	issuer    string
+	duration  time.Duration
+}
+
+// JWTClaims represents custom JWT claims
+type JWTClaims struct {
+	UserID   string `json:"user_id"`
+	Email    string `json:"email"`
+	Username string `json:"username"`
+	jwt.RegisteredClaims
+}
+
+// RefreshTokenClaims represents refresh token claims
+type RefreshTokenClaims struct {
+	UserID string `json:"user_id"`
+	jwt.RegisteredClaims
+}
+
+// NewJWTManager creates a new JWT manager
+func NewJWTManager(secretKey, issuer string, duration time.Duration) *JWTManager {
+	return &JWTManager{
+		secretKey: secretKey,
+		issuer:    issuer,
+		duration:  duration,
+	}
+}
+
+// GenerateAccessToken generates a new access token
+func (m *JWTManager) GenerateAccessToken(userID, email, username string) (string, error) {
+	claims := JWTClaims{
+		UserID:   userID,
+		Email:    email,
+		Username: username,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(m.duration)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			Issuer:    m.issuer,
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(m.secretKey))
+}
+
+// GenerateRefreshToken generates a new refresh token
+func (m *JWTManager) GenerateRefreshToken(userID string) (string, error) {
+	claims := RefreshTokenClaims{
+		UserID: userID,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour * 7)), // 7 days
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			Issuer:    m.issuer,
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(m.secretKey))
+}
+
+// VerifyAccessToken verifies and parses an access token
+func (m *JWTManager) VerifyAccessToken(tokenString string) (*JWTClaims, error) {
+	claims := &JWTClaims{}
+	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+		}
+		return []byte(m.secretKey), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if !token.Valid {
+		return nil, errors.New("invalid token")
+	}
+
+	return claims, nil
+}
+
+// VerifyRefreshToken verifies and parses a refresh token
+func (m *JWTManager) VerifyRefreshToken(tokenString string) (*RefreshTokenClaims, error) {
+	claims := &RefreshTokenClaims{}
+	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+		}
+		return []byte(m.secretKey), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if !token.Valid {
+		return nil, errors.New("invalid token")
+	}
+
+	return claims, nil
+}
+
+// GenerateRandomToken generates a random token for password reset, etc.
+func GenerateRandomToken(length int) (string, error) {
+	token := make([]byte, length)
+	if _, err := rand.Read(token); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(token), nil
+}
+
+// GeneratePKCEChallenge generates a PKCE code challenge
+func GeneratePKCEChallenge() (codeVerifier, codeChallenge string, err error) {
+	bytes := make([]byte, 32)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", "", err
+	}
+
+	codeVerifier = hex.EncodeToString(bytes)
+
+	// For code_challenge, we'd need base64url encoding of SHA256(verifier)
+	// For simplicity in this example, using hex, but in production use base64url(sha256(verifier))
+	codeChallenge = codeVerifier
+
+	return
+}
+
+// GenerateStateToken generates a state token for OAuth/OIDC flows
+func GenerateStateToken() (string, error) {
+	return GenerateRandomToken(16)
+}