'lib' rewritten.

lib/Crypto/Utils.php

@@ -0,0 +1,63 @@
+<?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;
+
+/**
+ * Cryptographic utilities.
+ *
+ * @author Marcin Łojewski <dev@mlojewski.me>
+ */
+final class Utils
+{
+    /**
+     * Convert hexadecimal message to its base64 form.
+     *
+     * @param $hex string The hexadecimal encoded message.
+     *
+     * @return string The same message encoded in base64.
+     */
+    public static function hexToBase64($hex)
+    {
+        $hexChr = "";
+        foreach (str_split($hex, 2) as $hexPair) {
+            $hexChr .= chr(hexdec($hexPair));
+        }
+        return base64_encode($hexChr);
+    }
+
+    /**
+     * Generate random string from given alphabet.
+     *
+     * @param $length   int The output string length.
+     * @param $alphabet string The output string alphabet.
+     *
+     * @return string Random string from given alphabet.
+     */
+    public static function randomString($length, $alphabet)
+    {
+        $string = "";
+        for ($idx = 0; $idx != $length; ++$idx) {
+            $string .= $alphabet[mt_rand(0, strlen($alphabet) - 1)];
+        }
+        return $string;
+    }
+}