[main] Login email before username (#57400)

* Swap order of login fields

* Validate email field before validating the username field.

Co-authored-by: linoman <2051016+linoman@users.noreply.github.com>

pkg/services/user/userimpl/store.go

@@ -170,27 +170,30 @@ func (ss *sqlStore) GetByLogin(ctx context.Context, query *user.GetUserByLoginQu
 			return user.ErrUserNotFound
 		}
 
-		// Try and find the user by login first.
-		// It's not sufficient to assume that a LoginOrEmail with an "@" is an email.
-		where := "login=?"
-		if ss.cfg.CaseInsensitiveLogin {
-			where = "LOWER(login)=LOWER(?)"
-		}
-
-		has, err := sess.Where(ss.notServiceAccountFilter()).Where(where, query.LoginOrEmail).Get(usr)
-		if err != nil {
-			return err
-		}
-
-		if !has && strings.Contains(query.LoginOrEmail, "@") {
-			// If the user wasn't found, and it contains an "@" fallback to finding the
-			// user by email.
+		var where string
+		var has bool
+		var err error
 
+		// Since username can be an email address, attempt login with email address
+		// first if the login field has the "@" symbol.
+		if strings.Contains(query.LoginOrEmail, "@") {
 			where = "email=?"
 			if ss.cfg.CaseInsensitiveLogin {
 				where = "LOWER(email)=LOWER(?)"
 			}
-			usr = &user.User{}
+			has, err = sess.Where(ss.notServiceAccountFilter()).Where(where, query.LoginOrEmail).Get(usr)
+
+			if err != nil {
+				return err
+			}
+		}
+
+		// Look for the login field instead of email
+		if !has {
+			where = "login=?"
+			if ss.cfg.CaseInsensitiveLogin {
+				where = "LOWER(login)=LOWER(?)"
+			}
 			has, err = sess.Where(ss.notServiceAccountFilter()).Where(where, query.LoginOrEmail).Get(usr)
 		}
 
@@ -199,7 +202,6 @@ func (ss *sqlStore) GetByLogin(ctx context.Context, query *user.GetUserByLoginQu
 		} else if !has {
 			return user.ErrUserNotFound
 		}
-
 		if ss.cfg.CaseInsensitiveLogin {
 			if err := ss.userCaseInsensitiveLoginConflict(ctx, sess, usr.Login, usr.Email); err != nil {
 				return err
@@ -207,10 +209,8 @@ func (ss *sqlStore) GetByLogin(ctx context.Context, query *user.GetUserByLoginQu
 		}
 		return nil
 	})
-	if err != nil {
-		return nil, err
-	}
-	return usr, nil
+
+	return usr, err
 }
 
 func (ss *sqlStore) GetByEmail(ctx context.Context, query *user.GetUserByEmailQuery) (*user.User, error) {

pkg/services/user/userimpl/store_test.go

@@ -202,6 +202,47 @@ func TestIntegrationUserDataAccess(t *testing.T) {
 			require.Error(t, err)
 		})
 
+		t.Run("GetByLogin - user2 uses user1.email as login", func(t *testing.T) {
+			// create user_1
+			user1 := &user.User{
+				Email:      "user_1@mail.com",
+				Name:       "user_1",
+				Login:      "user_1",
+				Password:   "user_1_password",
+				Created:    time.Now(),
+				Updated:    time.Now(),
+				IsDisabled: true,
+			}
+			_, err := userStore.Insert(context.Background(), user1)
+			require.Nil(t, err)
+
+			// create user_2
+			user2 := &user.User{
+				Email:      "user_2@mail.com",
+				Name:       "user_2",
+				Login:      "user_1@mail.com",
+				Password:   "user_2_password",
+				Created:    time.Now(),
+				Updated:    time.Now(),
+				IsDisabled: true,
+			}
+			_, err = userStore.Insert(context.Background(), user2)
+			require.Nil(t, err)
+
+			// query user database for user_1 email
+			query := user.GetUserByLoginQuery{LoginOrEmail: "user_1@mail.com"}
+			result, err := userStore.GetByLogin(context.Background(), &query)
+			require.Nil(t, err)
+
+			// expect user_1 as result
+			require.Equal(t, user1.Email, result.Email)
+			require.Equal(t, user1.Login, result.Login)
+			require.Equal(t, user1.Name, result.Name)
+			require.NotEqual(t, user2.Email, result.Email)
+			require.NotEqual(t, user2.Login, result.Login)
+			require.NotEqual(t, user2.Name, result.Name)
+		})
+
 		ss.Cfg.CaseInsensitiveLogin = false
 	})