kleinTodo/common/jwt/verify.go

package jwt

import (
	_ "context"
	"errors"
	"fmt"
	"net/http"
	"os"
	"strings"

	"gitea.kleinsense.nl/DariusKlein/kleinTodo/common"
	"github.com/golang-jwt/jwt/v5"
)

func GetVerifiedUser(r *http.Request) (string, error) {
	authHeader := r.Header.Get(common.AuthHeader)
	if authHeader == "" {
		return "", errors.New("authorization header is required")
	}

	parts := strings.Split(authHeader, " ")
	if len(parts) != 2 || strings.ToLower(parts[0]) != "bearer" {
		return "", errors.New("authorization header format must be Bearer {token}")
	}

	verifiedUser, err := VerifyJWT(parts[1])
	if err != nil {
		return "", fmt.Errorf("invalid token: %w", err)
	}

	return verifiedUser, nil
}

// VerifyJWT verify JWT token and returns user object
func VerifyJWT(authToken string) (string, error) {
	//get jwt secret from environment
	secret := os.Getenv("JWT_SECRET")
	//parse jwt token
	token, err := jwt.ParseWithClaims(authToken, &jwt.RegisteredClaims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})
	if err != nil {
		return "", err
	}
	subject := token.Claims.(*jwt.RegisteredClaims).Subject
	return subject, err
}