serve frontend from go

internal/auth/jwt.go

@@ -0,0 +1,79 @@
+package auth
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"git.schreifuchs.ch/schreifuchs/ng-blog/internal/model"
+	jwt "github.com/golang-jwt/jwt/v5"
+)
+
+var ErrJWTInvalid = errors.New("JWT not valid")
+
+func (s *Service) createJWT(user *model.User) (token string, err error) {
+	claims := &Claims{
+		Role:   user.Role,
+		UserID: user.ID,
+		RegisteredClaims: jwt.RegisteredClaims{
+			Subject: user.UUID.String(),
+			ExpiresAt: &jwt.NumericDate{
+				Time: time.Now().Add(s.cfg.ValidDuration),
+			},
+		},
+	}
+	return jwt.NewWithClaims(jwt.SigningMethodHS512, claims).SignedString([]byte(s.cfg.Secret))
+}
+
+// validateJWT returns the token Claims and if token ist invalid ErrJWTInvalid
+func (s *Service) validateJWT(tokenString string) (claims Claims, err error) {
+	_, err = jwt.ParseWithClaims(tokenString, &claims, func(token *jwt.Token) (any, error) {
+		// Don't forget to validate the alg is what you expect:
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+		}
+
+		return []byte(s.cfg.Secret), nil
+	})
+	if err != nil {
+		return
+	}
+
+	if claims.ExpiresAt.Before(time.Now()) {
+		err = ErrJWTInvalid
+		return
+	}
+
+	// check if user has logged out this token
+	var invalidated bool
+	err = s.db.Model(&model.InvalidJWT{}).
+		Select("count(*) > 0").
+		Where("jwt = ?", tokenString).
+		Find(&invalidated).
+		Error
+
+	if invalidated || err != nil {
+		err = ErrJWTInvalid
+		return
+	}
+	return
+}
+
+// extractToken extracts the Bearer token from the request
+func extractToken(r *http.Request) (token string, err error) {
+	tokenHeader := r.Header.Get("Authorization") // Grab the token from the header
+
+	if tokenHeader == "" {
+		err = errors.New("missing token")
+		return
+	}
+
+	token = strings.TrimPrefix(tokenHeader, "Bearer ")
+
+	if token == "" {
+		err = errors.New("malformed token")
+	}
+	return
+}