add OAuth authentication with JWT tokens and API key support

portal/internal/auth/jwt.go

@@ -0,0 +1,145 @@
+// Package auth provides authentication and authorization functionality
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+var (
+	ErrInvalidToken = errors.New("invalid token")
+	ErrExpiredToken = errors.New("token has expired")
+)
+
+// TokenPair contains access and refresh tokens
+type TokenPair struct {
+	AccessToken  string `json:"access_token"`
+	RefreshToken string `json:"refresh_token"`
+	TokenType    string `json:"token_type"`
+	ExpiresIn    int64  `json:"expires_in"`
+}
+
+// Claims represents JWT claims for access tokens
+type Claims struct {
+	jwt.RegisteredClaims
+	Type  string `json:"type"`
+	Email string `json:"email,omitempty"`
+}
+
+// JWTManager handles JWT token operations
+type JWTManager struct {
+	secretKey          []byte
+	accessTokenExpiry  time.Duration
+	refreshTokenExpiry time.Duration
+}
+
+// NewJWTManager creates a new JWT manager
+func NewJWTManager(secret string) *JWTManager {
+	return &JWTManager{
+		secretKey:          []byte(secret),
+		accessTokenExpiry:  time.Hour,
+		refreshTokenExpiry: 30 * 24 * time.Hour,
+	}
+}
+
+// GenerateTokenPair creates a new access/refresh token pair
+func (m *JWTManager) GenerateTokenPair(developerID, email string) (*TokenPair, error) {
+	accessToken, err := m.generateToken(developerID, email, "access", m.accessTokenExpiry)
+	if err != nil {
+		return nil, fmt.Errorf("generate access token: %w", err)
+	}
+
+	refreshToken, err := m.generateToken(developerID, email, "refresh", m.refreshTokenExpiry)
+	if err != nil {
+		return nil, fmt.Errorf("generate refresh token: %w", err)
+	}
+
+	return &TokenPair{
+		AccessToken:  accessToken,
+		RefreshToken: refreshToken,
+		TokenType:    "Bearer",
+		ExpiresIn:    int64(m.accessTokenExpiry.Seconds()),
+	}, nil
+}
+
+func (m *JWTManager) generateToken(subject, email, tokenType string, expiry time.Duration) (string, error) {
+	now := time.Now()
+	claims := Claims{
+		RegisteredClaims: jwt.RegisteredClaims{
+			Subject:   subject,
+			IssuedAt:  jwt.NewNumericDate(now),
+			ExpiresAt: jwt.NewNumericDate(now.Add(expiry)),
+			Issuer:    "mosis-portal",
+		},
+		Type:  tokenType,
+		Email: email,
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(m.secretKey)
+}
+
+// ValidateAccessToken validates an access token and returns the claims
+func (m *JWTManager) ValidateAccessToken(tokenString string) (*Claims, error) {
+	return m.validateToken(tokenString, "access")
+}
+
+// ValidateRefreshToken validates a refresh token and returns the claims
+func (m *JWTManager) ValidateRefreshToken(tokenString string) (*Claims, error) {
+	return m.validateToken(tokenString, "refresh")
+}
+
+func (m *JWTManager) validateToken(tokenString, expectedType string) (*Claims, error) {
+	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 m.secretKey, nil
+	})
+
+	if err != nil {
+		if errors.Is(err, jwt.ErrTokenExpired) {
+			return nil, ErrExpiredToken
+		}
+		return nil, ErrInvalidToken
+	}
+
+	claims, ok := token.Claims.(*Claims)
+	if !ok || !token.Valid {
+		return nil, ErrInvalidToken
+	}
+
+	if claims.Type != expectedType {
+		return nil, ErrInvalidToken
+	}
+
+	return claims, nil
+}
+
+// GenerateAPIKey generates a new API key with the given prefix
+func GenerateAPIKey(prefix string) (string, error) {
+	// Generate 32 random bytes
+	bytes := make([]byte, 32)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+
+	// Encode as base64url (no padding)
+	encoded := base64.RawURLEncoding.EncodeToString(bytes)
+
+	return fmt.Sprintf("%s_%s", prefix, encoded), nil
+}
+
+// GenerateState generates a random state for OAuth
+func GenerateState() (string, error) {
+	bytes := make([]byte, 16)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(bytes), nil
+}