issue#77 Add support for remine password hashes

lib/Crypto/Redmine.php

@@ -0,0 +1,50 @@
+<?php
+/**
+ * Nextcloud - user_sql
+ *
+ * @copyright 2018 Marcin Łojewski <dev@mlojewski.me>
+ * @author    Marcin Łojewski <dev@mlojewski.me>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace OCA\UserSQL\Crypto;
+
+/**
+ * Redmine MD5 hash implementation.
+ *
+ * @author Marcin Łojewski <dev@mlojewski.me>
+ */
+class Redmine extends AbstractAlgorithm
+{
+    /**
+     * @inheritdoc
+     */
+    public function getPasswordHash($password, $salt = null)
+    {
+        if (is_null($salt)) {
+            return false;
+        }
+
+        return sha1($salt . sha1($password));
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function getAlgorithmName()
+    {
+        return "Redmine";
+    }
+}