Merge pull request #8630 from nextcloud/ldap-cachekey-sha256

use hash algo that's robust against collisions

apps/user_ldap/lib/Connection.php

@@ -218,7 +218,7 @@ class Connection extends LDAPUtility {
 		if(is_null($key)) {
 			return $prefix;
 		}
-		return $prefix.md5($key);
+		return $prefix.hash('sha256', $key);
 	}
 
 	/**

apps/user_ldap/lib/Proxy.php

@@ -163,7 +163,7 @@ abstract class Proxy {
 		if($key === null) {
 			return $prefix;
 		}
-		return $prefix.md5($key);
+		return $prefix.hash('sha256', $key);
 	}
 
 	/**