feat: impl bearer auth middleware

apps/backend/internal/auth/err.go

@@ -1,6 +1,11 @@
 package auth
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
+
+var ErrUnauthenticatedRequest = errors.New("unauthenticated request")
 
 type InvalidAccessTokenError struct {
 	err error

apps/backend/internal/auth/http.go

@@ -3,6 +3,7 @@ package auth
 import (
 	"errors"
 
+	"github.com/get-drexa/drexa/internal/user"
 	"github.com/gofiber/fiber/v2"
 )
 
@@ -20,7 +21,7 @@ type registerRequest struct {
 }
 
 type loginResponse struct {
-	User         User   `json:"user"`
+	User         user.User `json:"user"`
 	AccessToken  string    `json:"accessToken"`
 	RefreshToken string    `json:"refreshToken"`
 }
@@ -56,7 +57,7 @@ func login(c *fiber.Ctx) error {
 	}
 
 	return c.JSON(loginResponse{
-		User:         result.User,
+		User:         *result.User,
 		AccessToken:  result.AccessToken,
 		RefreshToken: result.RefreshToken,
 	})
@@ -83,7 +84,7 @@ func register(c *fiber.Ctx) error {
 	}
 
 	return c.JSON(loginResponse{
-		User:         result.User,
+		User:         *result.User,
 		AccessToken:  result.AccessToken,
 		RefreshToken: result.RefreshToken,
 	})

apps/backend/internal/auth/middleware.go

@@ -0,0 +1,56 @@
+package auth
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/get-drexa/drexa/internal/user"
+	"github.com/gofiber/fiber/v2"
+)
+
+const authenticatedUserKey = "authenticatedUser"
+
+// NewBearerAuthMiddleware is a middleware that authenticates a request using a bearer token.
+// To obtain the authenticated user in subsequent handlers, see AuthenticatedUser.
+func NewBearerAuthMiddleware(s *Service) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		authHeader := c.Get("Authorization")
+		if authHeader == "" {
+			return c.SendStatus(fiber.StatusUnauthorized)
+		}
+
+		parts := strings.Split(authHeader, " ")
+		if len(parts) != 2 || parts[0] != "Bearer" {
+			return c.SendStatus(fiber.StatusUnauthorized)
+		}
+
+		token := parts[1]
+		u, err := s.AuthenticateWithAccessToken(c.Context(), token)
+		if err != nil {
+			var e *InvalidAccessTokenError
+			if errors.As(err, &e) {
+				return c.SendStatus(fiber.StatusUnauthorized)
+			}
+
+			var nf *user.NotFoundError
+			if errors.As(err, &nf) {
+				return c.SendStatus(fiber.StatusUnauthorized)
+			}
+
+			return c.SendStatus(fiber.StatusInternalServerError)
+		}
+
+		c.Locals(authenticatedUserKey, u)
+
+		return c.Next()
+	}
+}
+
+// AuthenticatedUser returns the authenticated user from the given fiber context.
+// Returns ErrUnauthenticatedRequest if not authenticated.
+func AuthenticatedUser(c *fiber.Ctx) (*user.User, error) {
+	if u, ok := c.Locals(authenticatedUserKey).(*user.User); ok {
+		return u, nil
+	}
+	return nil, ErrUnauthenticatedRequest
+}

apps/backend/internal/auth/service.go

@@ -5,11 +5,13 @@ import (
 	"encoding/hex"
 	"errors"
 
+	"github.com/get-drexa/drexa/internal/user"
+	"github.com/google/uuid"
 	"github.com/uptrace/bun"
 )
 
 type LoginResult struct {
-	User         User
+	User         *user.User
 	AccessToken  string
 	RefreshToken string
 }
@@ -19,6 +21,7 @@ var ErrUserExists = errors.New("user already exists")
 
 type Service struct {
 	db          *bun.DB
+	userService *user.Service
 	tokenConfig TokenConfig
 }
 
@@ -28,32 +31,33 @@ type registerOptions struct {
 	password    string
 }
 
-func NewService(db *bun.DB, tokenConfig TokenConfig) *Service {
+func NewService(db *bun.DB, userService *user.Service, tokenConfig TokenConfig) *Service {
 	return &Service{
 		db:          db,
+		userService: userService,
 		tokenConfig: tokenConfig,
 	}
 }
 
 func (s *Service) LoginWithEmailAndPassword(ctx context.Context, email, password string) (*LoginResult, error) {
-	var user User
+	var u user.User
 
-	err := s.db.NewSelect().Model(&user).Where("email = ?", email).Scan(ctx)
+	err := s.db.NewSelect().Model(&u).Where("email = ?", email).Scan(ctx)
 	if err != nil {
 		return nil, err
 	}
 
-	ok, err := VerifyPassword(password, user.Password)
+	ok, err := VerifyPassword(password, u.Password)
 	if err != nil || !ok {
 		return nil, ErrInvalidCredentials
 	}
 
-	at, err := GenerateAccessToken(&user, &s.tokenConfig)
+	at, err := GenerateAccessToken(&u, &s.tokenConfig)
 	if err != nil {
 		return nil, err
 	}
 
-	rt, err := GenerateRefreshToken(&user, &s.tokenConfig)
+	rt, err := GenerateRefreshToken(&u, &s.tokenConfig)
 	if err != nil {
 		return nil, err
 	}
@@ -64,19 +68,19 @@ func (s *Service) LoginWithEmailAndPassword(ctx context.Context, email, password
 	}
 
 	return &LoginResult{
-		User:         user,
+		User:         &u,
 		AccessToken:  at,
 		RefreshToken: hex.EncodeToString(rt.Token),
 	}, nil
 }
 
 func (s *Service) Register(ctx context.Context, opts registerOptions) (*LoginResult, error) {
-	user := User{
+	u := user.User{
 		Email:       opts.email,
 		DisplayName: opts.displayName,
 	}
 
-	exists, err := s.db.NewSelect().Model(&user).Where("email = ?", opts.email).Exists(ctx)
+	exists, err := s.db.NewSelect().Model(&u).Where("email = ?", opts.email).Exists(ctx)
 	if err != nil {
 		return nil, err
 	}
@@ -84,29 +88,43 @@ func (s *Service) Register(ctx context.Context, opts registerOptions) (*LoginRes
 		return nil, ErrUserExists
 	}
 
-	user.Password, err = HashPassword(opts.password)
+	u.Password, err = HashPassword(opts.password)
 	if err != nil {
 		return nil, err
 	}
 
-	_, err = s.db.NewInsert().Model(&user).Exec(ctx)
+	_, err = s.db.NewInsert().Model(&u).Exec(ctx)
 	if err != nil {
 		return nil, err
 	}
 
-	at, err := GenerateAccessToken(&user, &s.tokenConfig)
+	at, err := GenerateAccessToken(&u, &s.tokenConfig)
 	if err != nil {
 		return nil, err
 	}
 
-	rt, err := GenerateRefreshToken(&user, &s.tokenConfig)
+	rt, err := GenerateRefreshToken(&u, &s.tokenConfig)
 	if err != nil {
 		return nil, err
 	}
 
 	return &LoginResult{
-		User:         user,
+		User:         &u,
 		AccessToken:  at,
 		RefreshToken: hex.EncodeToString(rt.Token),
 	}, nil
 }
+
+func (s *Service) AuthenticateWithAccessToken(ctx context.Context, token string) (*user.User, error) {
+	claims, err := ParseAccessToken(token, &s.tokenConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	id, err := uuid.Parse(claims.Subject)
+	if err != nil {
+		return nil, newInvalidAccessTokenError(err)
+	}
+
+	return s.userService.UserByID(ctx, id)
+}

apps/backend/internal/auth/tokens.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/get-drexa/drexa/internal/user"
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/uuid"
 	"github.com/uptrace/bun"
@@ -35,7 +36,7 @@ type RefreshToken struct {
 	CreatedAt time.Time `bun:"created_at,notnull"`
 }
 
-func GenerateAccessToken(user *User, c *TokenConfig) (string, error) {
+func GenerateAccessToken(user *user.User, c *TokenConfig) (string, error) {
 	now := time.Now()
 
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.RegisteredClaims{
@@ -54,7 +55,7 @@ func GenerateAccessToken(user *User, c *TokenConfig) (string, error) {
 	return signed, nil
 }
 
-func GenerateRefreshToken(user *User, c *TokenConfig) (*RefreshToken, error) {
+func GenerateRefreshToken(user *user.User, c *TokenConfig) (*RefreshToken, error) {
 	now := time.Now()
 
 	buf := make([]byte, refreshTokenByteLength)
@@ -80,6 +81,8 @@ func GenerateRefreshToken(user *User, c *TokenConfig) (*RefreshToken, error) {
 	}, nil
 }
 
+// ParseAccessToken parses a JWT access token and returns the claims.
+// Returns an InvalidAccessTokenError if the token is invalid.
 func ParseAccessToken(token string, c *TokenConfig) (*jwt.RegisteredClaims, error) {
 	parsed, err := jwt.ParseWithClaims(token, &jwt.RegisteredClaims{}, func(token *jwt.Token) (any, error) {
 		return c.SecretKey, nil

apps/backend/internal/drexa/server.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/get-drexa/drexa/internal/auth"
 	"github.com/get-drexa/drexa/internal/database"
+	"github.com/get-drexa/drexa/internal/user"
 	"github.com/gofiber/fiber/v2"
 )
 
@@ -24,7 +25,8 @@ func NewServer(c ServerConfig) *fiber.App {
 	app := fiber.New()
 	db := database.NewFromPostgres(c.PostgresURL)
 
-	authService := auth.NewService(db, auth.TokenConfig{
+	userService := user.NewService(db)
+	authService := auth.NewService(db, userService, auth.TokenConfig{
 		Issuer:    c.JWTIssuer,
 		Audience:  c.JWTAudience,
 		SecretKey: c.JWTSecretKey,

apps/backend/internal/user/err.go

@@ -0,0 +1,19 @@
+package user
+
+import (
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+type NotFoundError struct {
+	id uuid.UUID
+}
+
+func newNotFoundError(id uuid.UUID) *NotFoundError {
+	return &NotFoundError{id}
+}
+
+func (e *NotFoundError) Error() string {
+	return fmt.Sprintf("user not found: %v", e.id)
+}

apps/backend/internal/user/service.go

@@ -0,0 +1,32 @@
+package user
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+
+	"github.com/google/uuid"
+	"github.com/uptrace/bun"
+)
+
+type Service struct {
+	db *bun.DB
+}
+
+func NewService(db *bun.DB) *Service {
+	return &Service{
+		db: db,
+	}
+}
+
+func (s *Service) UserByID(ctx context.Context, id uuid.UUID) (*User, error) {
+	var user User
+	err := s.db.NewSelect().Model(&user).Where("id = ?", id).Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, newNotFoundError(id)
+		}
+		return nil, err
+	}
+	return &user, nil
+}

apps/backend/internal/user/user.go

@@ -1,4 +1,4 @@
-package auth
+package user
 
 import (
 	"github.com/google/uuid"