fix(caldav): no failed login emails for tokens (#1252)

Prevent Vikunja from sending mail notifications for failed login attempts if CalDav token is used.

Before, as the provided password value was tested against the user password regardless of whether it was a CalDav token, it triggered a failed login attempt email every three times.

Reviewed-on: vikunja/api#1252
Reviewed-by: konrad <k@knt.li>
Co-authored-by: Luca Bernstein <luca@lucabernstein.com>
Co-committed-by: Luca Bernstein <luca@lucabernstein.com>

pkg/routes/caldav/auth.go

@@ -22,6 +22,7 @@ import (
 	"code.vikunja.io/api/pkg/db"
 	"code.vikunja.io/api/pkg/log"
 	"code.vikunja.io/api/pkg/user"
+	"xorm.io/xorm"
 
 	"github.com/labstack/echo/v4"
 	"golang.org/x/crypto/bcrypt"
@@ -35,37 +36,47 @@ func BasicAuth(username, password string, c echo.Context) (bool, error) {
 		Username: username,
 		Password: password,
 	}
-	u, err := user.CheckUserCredentials(s, credentials)
-	if err != nil && !user.IsErrWrongUsernameOrPassword(err) && !user.IsErrAccountIsNotLocal(err) {
-		log.Errorf("Error during basic auth for caldav: %v", err)
+	var err error
+	u, err := checkUserCaldavTokens(s, credentials)
+	if user.IsErrUserDoesNotExist(err) {
 		return false, nil
 	}
-
-	if err == nil {
+	if u == nil {
+		u, err = user.CheckUserCredentials(s, credentials)
+		if err != nil {
+			log.Errorf("Error during basic auth for caldav: %v", err)
+			return false, nil
+		}
+	}
+	if u != nil && err == nil {
 		c.Set("userBasicAuth", u)
 		return true, nil
 	}
+	return false, nil
+}
 
-	tokens, err := user.GetCaldavTokens(u)
+func checkUserCaldavTokens(s *xorm.Session, login *user.Login) (*user.User, error) {
+	usr, err := user.GetUserByUsername(s, login.Username)
+	if err != nil || usr == nil {
+		log.Warningf("Error while retrieving users from database: %v", err)
+		return nil, err
+	}
+	tokens, err := user.GetCaldavTokens(usr)
 	if err != nil {
 		log.Errorf("Error while getting tokens for caldav auth: %v", err)
-		return false, nil
+		return nil, err
 	}
-
 	// Looping over all tokens until we find one that matches
 	for _, token := range tokens {
-		err = bcrypt.CompareHashAndPassword([]byte(token.Token), []byte(password))
+		err = bcrypt.CompareHashAndPassword([]byte(token.Token), []byte(login.Password))
 		if err != nil {
 			if errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
 				continue
 			}
 			log.Errorf("Error while verifying tokens for caldav auth: %v", err)
-			return false, nil
+			return nil, nil
 		}
-
-		c.Set("userBasicAuth", u)
-		return true, nil
+		return usr, nil
 	}
-
-	return false, nil
+	return nil, nil
 }