Adjust the SAML control flow to allow LDAP identities to be added to an existing SAML user.

2 files changed, 27 insertions, 3 deletions

diff --git a/lib/gitlab/o_auth/user.rb b/lib/gitlab/o_auth/user.rb
index 356e96fcbab..268ee115028 100644
--- a/lib/gitlab/o_auth/user.rb
+++ b/lib/gitlab/o_auth/user.rb
@@ -96,7 +96,7 @@ module Gitlab
         # Look for a corresponding person with same uid in any of the configured LDAP providers
         Gitlab::LDAP::Config.providers.each do |provider|
           adapter = Gitlab::LDAP::Adapter.new(provider)
-          @ldap_person = Gitlab::LDAP::Person.find_by_uid(auth_hash.uid, adapter)
+          @ldap_person = Gitlab::LDAP::Person.find_by_dn(auth_hash.uid, adapter)
           break if @ldap_person
         end
         @ldap_person
diff --git a/lib/gitlab/saml/user.rb b/lib/gitlab/saml/user.rb
index dba4bbfc899..6f7d4825ae5 100644
--- a/lib/gitlab/saml/user.rb
+++ b/lib/gitlab/saml/user.rb
@@ -12,12 +12,12 @@ module Gitlab
       end
 
       def gl_user
-        @user ||= find_by_uid_and_provider
-
         if auto_link_ldap_user?
           @user ||= find_or_create_ldap_user
         end
 
+        @user ||= find_by_uid_and_provider
+
         if auto_link_saml_user?
           @user ||= find_by_email
         end
@@ -62,6 +62,30 @@ module Gitlab
         !Gitlab::Saml::Config.external_groups.nil?
       end
 
+      def find_or_create_ldap_user
+        return unless ldap_person
+
+        # If a corresponding person exists with same uid in a LDAP server,
+        # check if the user already has a GitLab account
+        user = Gitlab::LDAP::User.find_by_uid_and_provider(ldap_person.dn, ldap_person.provider)
+        if user
+          # Case when a LDAP user already exists in Gitlab. Add the SAML identity to existing account.
+          user.identities.build(extern_uid: auth_hash.uid, provider: auth_hash.provider)
+        else
+          # No account found using LDAP in Gitlab yet: check if there is a SAML account with
+          # the passed uid and provider
+          user = find_by_uid_and_provider
+          if user.nil?
+            # No SAML account found, build a new user.
+            user = build_new_user
+          end
+          # Correct account is present, add the LDAP Identity to the user.
+          user.identities.new(provider: ldap_person.provider, extern_uid: ldap_person.dn)
+        end
+
+        user
+      end
+
       def auth_hash=(auth_hash)
         @auth_hash = Gitlab::Saml::AuthHash.new(auth_hash)
       end