diff --git a/auth/ldap/ldap.go b/auth/ldap/ldap.go
index 53d17a174..8de4d47fb 100644
--- a/auth/ldap/ldap.go
+++ b/auth/ldap/ldap.go
@@ -76,31 +76,25 @@ func (l *Auth) Authenticate(m models.AuthModel) (*models.User, error) {
 
 	scope := openldap.LDAP_SCOPE_SUBTREE // LDAP_SCOPE_BASE, LDAP_SCOPE_ONELEVEL, LDAP_SCOPE_SUBTREE
 	filter := "objectClass=*"
-	attributes := []string{"cn", "mail", "uid"}
+	attributes := []string{"mail"}
 
 	result, err := ldap.SearchAll(baseDn, scope, filter, attributes)
 	if err != nil {
 		return nil, err
 	}
-	if len(result.Entries()) != 1 {
-		log.Warningf("Found more than one entry.")
-		return nil, nil
-	}
-	en := result.Entries()[0]
 	u := models.User{}
-	for _, attr := range en.Attributes() {
-		val := attr.Values()[0]
-		switch attr.Name() {
-		case "uid":
-			u.Username = val
-		case "mail":
-			u.Email = val
-		case "cn":
-			u.Realname = val
+	if len(result.Entries()) == 1 {
+		en := result.Entries()[0]
+		for _, attr := range en.Attributes() {
+			val := attr.Values()[0]
+			if attr.Name() == "mail" {
+				u.Email = val
+			}
 		}
 	}
 
-	log.Debug("username:", u.Username, ",email:", u.Email, ",realname:", u.Realname)
+	u.Username = m.Principal
+	log.Debug("username:", u.Username, ",email:", u.Email)
 
 	exist, err := dao.UserExists(u, "username")
 	if err != nil {
@@ -114,6 +108,7 @@ func (l *Auth) Authenticate(m models.AuthModel) (*models.User, error) {
 		}
 		u.UserID = currentUser.UserID
 	} else {
+		u.Realname = m.Principal
 		u.Password = "12345678AbC"
 		u.Comment = "registered from LDAP."
 		userID, err := dao.Register(u)
diff --git a/dao/register.go b/dao/register.go
index f3e66cb1a..6f5351504 100644
--- a/dao/register.go
+++ b/dao/register.go
@@ -74,16 +74,13 @@ func validate(user models.User) error {
 		return errors.New("Username already exists.")
 	}
 
-	if m, _ := regexp.MatchString(`^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$`, user.Email); !m {
-		return errors.New("Email with illegal format.")
-	}
-
-	if isIllegalLength(user.Email, 0, -1) {
-		return errors.New("Email cannot empty.")
-	}
-
-	if exist, _ := UserExists(models.User{Email: user.Email}, "email"); exist {
-		return errors.New("Email already exists.")
+	if len(user.Email) > 0 {
+		if m, _ := regexp.MatchString(`^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$`, user.Email); !m {
+			return errors.New("Email with illegal format.")
+		}
+		if exist, _ := UserExists(models.User{Email: user.Email}, "email"); exist {
+			return errors.New("Email already exists.")
+		}
 	}
 
 	if isIllegalLength(user.Realname, 0, 20) {