Resolve "Dashes not supported in CN for LDAP Group Sync on first login"

changelogs/unreleased/36753-dashes-not-supported-in-cn-for-ldap-group-sync-on-first-login.yml

+---
+title: Support dashes in LDAP group CN for sync on users first log in
+merge_request: 20402
+author:
+type: fixed

ee/lib/ee/gitlab/auth/ldap/person.rb

@@ -91,7 +91,7 @@ module EE
           def cn_from_memberof(memberof)
             # Only get the first CN value of the string, that's the one that contains
             # the group name
-            memberof.match(/(?:cn=([\w\s]+))/i)&.captures&.first
+            memberof.match(/(?:cn=([\w\s-]+))/i)&.captures&.first
           end
         end
       end

ee/spec/lib/gitlab/auth/ldap/person_spec.rb

@@ -232,7 +232,7 @@ describe Gitlab::Auth::LDAP::Person do
     it 'gets the group cn from the memberof value' do
       person = described_class.new(entry, 'ldapmain')
 
-      expect(person.cn_from_memberof('cN=Group Policy Creator Owners,CN=Users,DC=Vosmaer,DC=com'))
+      expect(person.cn_from_memberof('CN=Group Policy Creator Owners,CN=Users,DC=Vosmaer,DC=com'))
         .to eq('Group Policy Creator Owners')
     end
 
@@ -242,6 +242,13 @@ describe Gitlab::Auth::LDAP::Person do
       expect(person.cn_from_memberof('DC=Vosmaer,DC=com'))
         .to be_nil
     end
+
+    it "supports dashes in the group cn" do
+      person = described_class.new(entry, 'ldapmain')
+
+      expect(person.cn_from_memberof('CN=Group-Policy-Creator-Owners,CN=Users,DC=Vosmaer,DC=com'))
+        .to eq('Group-Policy-Creator-Owners')
+    end
   end
 
   describe '#group_cns' do