1 files changed, 91 insertions, 0 deletions
diff --git a/Core/Encoder/BasePasswordEncoder.php b/Core/Encoder/BasePasswordEncoder.php
new file mode 100644
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+++ b/Core/Encoder/BasePasswordEncoder.php
@@ -0,0 +1,91 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Core\Encoder;
+
+/**
+ * BasePasswordEncoder is the base class for all password encoders.
+ *
+ * @author Fabien Potencier <fabien.potencier@symfony-project.com>
+ */
+abstract class BasePasswordEncoder implements PasswordEncoderInterface
+{
+    /**
+     * Demerges a merge password and salt string.
+     *
+     * @param string $mergedPasswordSalt The merged password and salt string
+     *
+     * @return array An array where the first element is the password and the second the salt
+     */
+    protected function demergePasswordAndSalt($mergedPasswordSalt)
+    {
+        if (empty($mergedPasswordSalt)) {
+            return array('', '');
+        }
+
+        $password = $mergedPasswordSalt;
+        $salt = '';
+        $saltBegins = strrpos($mergedPasswordSalt, '{');
+
+        if (false !== $saltBegins && $saltBegins + 1 < strlen($mergedPasswordSalt)) {
+            $salt = substr($mergedPasswordSalt, $saltBegins + 1, -1);
+            $password = substr($mergedPasswordSalt, 0, $saltBegins);
+        }
+
+        return array($password, $salt);
+    }
+
+    /**
+     * Merges a password and a salt.
+     *
+     * @param string $password the password to be used
+     * @param string $salt the salt to be used
+     *
+     * @return string a merged password and salt
+     */
+    protected function mergePasswordAndSalt($password, $salt)
+    {
+        if (empty($salt)) {
+            return $password;
+        }
+
+        if (false !== strrpos($salt, '{') || false !== strrpos($salt, '}')) {
+            throw new \InvalidArgumentException('Cannot use { or } in salt.');
+        }
+
+        return $password.'{'.$salt.'}';
+    }
+
+    /**
+     * Compares two passwords.
+     *
+     * This method implements a constant-time algorithm to compare passwords to
+     * avoid (remote) timing attacks.
+     *
+     * @param string $password1 The first password
+     * @param string $password2 The second password
+     *
+     * @return Boolean true if the two passwords are the same, false otherwise
+     */
+    protected function comparePasswords($password1, $password2)
+    {
+        if (strlen($password1) !== strlen($password2)) {
+            return false;
+        }
+
+        $result = 0;
+        for ($i = 0; $i < strlen($password1); $i++) {
+            $result |= ord($password1[$i]) ^ ord($password2[$i]);
+        }
+
+        return 0 === $result;
+    }
+}