KEYCLOAK-18695 Support user lookup by ID with Novell eDirectory

The LDAPOperationManager does not encode GUID correctly when looking up
federated users from Novell eDirectory.

The correct encoding can be found here:
https://support.novell.com/docs/Tids/Solutions/10096551.html

federation/ldap/src/main/java/org/keycloak/storage/ldap/idm/store/ldap/LDAPOperationManager.java

@@ -392,6 +392,8 @@ public class LDAPOperationManager {
             } catch (NamingException ne) {
                 filter = null;
             }
+        } else if (this.config.isEdirectoryGUID()) {
+            filter = "(&(objectClass=*)(" + getUuidAttributeName().toUpperCase() + LDAPConstants.EQUAL + LDAPUtil.convertGUIDToEdirectoryHexString(id) + "))";
         }
 
         if (filter == null) {

federation/ldap/src/main/java/org/keycloak/storage/ldap/idm/store/ldap/LDAPUtil.java

@@ -109,6 +109,26 @@ public class LDAPUtil {
         return result.toString();
     }
 
+    /**
+     * see http://support.novell.com/docs/Tids/Solutions/10096551.html
+     *
+     * @param guid A GUID in the form of a dashed String as the result of (@see LDAPUtil#convertToDashedString)
+     *
+     * @return A String representation in the form of \[0][1]\[2][3]\[4][5]\[6][7]\[8][9]\[10][11]\[12][13]\[14][15]
+     */
+    public static String convertGUIDToEdirectoryHexString(String guid) {
+        String withoutDash = guid.replace("-", "");
+        StringBuilder result = new StringBuilder();
+
+        for (int i = 0; i < withoutDash.length(); i++) {
+            result.append("\\");
+            result.append(withoutDash.charAt(i));
+            result.append(withoutDash.charAt(++i));
+        }
+
+        return result.toString().toUpperCase();
+    }
+
     /**
      * <p>Decode a raw byte array representing the value of the <code>objectGUID</code> attribute retrieved from Active
      * Directory.</p>