Add crypt lib

drupal/modules/epal/src/Crypt.php

+<?php
+
+namespace Drupal\epal;
+
+use Defuse\Crypto\Key;
+use Defuse\Crypto\Crypto;
+use \Exception;
+
+class Crypt
+{
+
+    private $fname; // store
+
+    public function __construct($fname)
+    {
+        if (is_string($fname)) {
+            $this->fname = $fname;
+        } else {
+            $this->fname = __DIR__ . "/../../../../../app.txt";
+        }
+    }
+
+    /**
+     * @throws \Exception If key is not found
+     * @return string The key to use
+     */
+    protected function loadKey()
+    {
+        if (!is_readable($this->fname) || !is_file($this->fname)) {
+            throw new \Exception(__METHOD__ . ':: No file');
+        }
+        $keystring = file_get_contents($this->fname);
+        if ($keystring === false) {
+            throw new \Exception(__METHOD__ . ':: Cannot load file');
+        }
+        return Key::loadFromAsciiSafeString($keystring);
+    }
+
+    /**
+     * Provided a string value, encrypt and return encrypted value
+     *
+     * @throws \Defuse\Crypto\Exception\EnvironmentIsBrokenException if encryption cannot be performed
+     * @throws \Exception If value to encode is not string
+     * @return hex encoded encrypted value
+     */
+    public function encrypt($data)
+    {
+        if (!is_string($data)) {
+            throw new \Exception("Data to be encoded can only be strings");
+        }
+        $key = $this->loadKey();
+        $dataenc = Crypto::encrypt($data, $key);
+        return $dataenc;
+    }
+
+    /**
+     * Provided a hex encoded encrypted value, decrypt and return original value
+     *
+     * @throws \Defuse\Crypto\Exception\WrongKeyOrModifiedCiphertextException if decrypt failed!
+     * @return string the original value
+     */
+    public function decrypt($dataenc)
+    {
+        $key = $this->loadKey();
+        $data = Crypto::decrypt($dataenc, $key);
+        return $data;
+    }
+}