1 files changed, 19 insertions, 0 deletions
diff --git a/lib/gitlab/auth.rb b/lib/gitlab/auth.rb
index 78d2196fbbe..ff1d1b13cc9 100644
--- a/lib/gitlab/auth.rb
+++ b/lib/gitlab/auth.rb
@@ -70,5 +70,24 @@ module Gitlab
     def log
       Gitlab::AppLogger
     end
+
+    def ldap_auth(login, password)
+      # Check user against LDAP backend if user is not authenticated
+      # Only check with valid login and password to prevent anonymous bind results
+      return nil unless ldap_conf.enabled && !login.blank? && !password.blank?
+
+      ldap = OmniAuth::LDAP::Adaptor.new(ldap_conf)
+      ldap_user = ldap.bind_as(
+        filter: Net::LDAP::Filter.eq(ldap.uid, login),
+        size: 1,
+        password: password
+      )
+
+      User.find_by_extern_uid_and_provider(ldap_user.dn, 'ldap') if ldap_user
+    end
+
+    def ldap_conf
+      @ldap_conf ||= Gitlab.config.ldap
+    end
   end
 end