Support SAML authentication (#25165)

Closes https://github.com/go-gitea/gitea/issues/5512

This PR adds basic SAML support
- Adds SAML 2.0 as an auth source
- Adds SAML configuration documentation
- Adds integration test:
- Use bare-bones SAML IdP to test protocol flow and test account is
linked successfully (only runs on Postgres by default)
- Adds documentation for configuring and running SAML integration test
locally

Future PRs:
- Support group mapping
- Support auto-registration (account linking)

Co-Authored-By: @jackHay22

---------

Co-authored-by: jackHay22 <jack@allspice.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: morphelinho <morphelinho@users.noreply.github.com>
Co-authored-by: Zettat123 <zettat123@gmail.com>
Co-authored-by: Yarden Shoham <git@yardenshoham.com>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: silverwind <me@silverwind.io>

1 files changed, 6 insertions, 2 deletions

diff --git a/web_src/js/features/admin/common.js b/web_src/js/features/admin/common.js
index 044976ea7b..4804163971 100644
--- a/web_src/js/features/admin/common.js
+++ b/web_src/js/features/admin/common.js
@@ -103,9 +103,9 @@ export function initAdminCommon() {
   // New authentication
   if ($('.admin.new.authentication').length > 0) {
     $('#auth_type').on('change', function () {
-      hideElem($('.ldap, .dldap, .smtp, .pam, .oauth2, .has-tls, .search-page-size, .sspi'));
+      hideElem($('.ldap, .dldap, .smtp, .pam, .oauth2, .has-tls, .search-page-size, .sspi, .saml'));
 
-      $('.ldap input[required], .binddnrequired input[required], .dldap input[required], .smtp input[required], .pam input[required], .oauth2 input[required], .has-tls input[required], .sspi input[required]').removeAttr('required');
+      $('.ldap input[required], .binddnrequired input[required], .dldap input[required], .smtp input[required], .pam input[required], .oauth2 input[required], .has-tls input[required], .sspi input[required], .saml input[required]').removeAttr('required');
       $('.binddnrequired').removeClass('required');
 
       const authType = $(this).val();
@@ -137,6 +137,10 @@ export function initAdminCommon() {
           showElem($('.sspi'));
           $('.sspi div.required input').attr('required', 'required');
           break;
+        case '8': // SAML
+          showElem($('.saml'));
+          $('.saml div.required input').attr('required', 'required');
+          break;
       }
       if (authType === '2' || authType === '5') {
         onSecurityProtocolChange();