The start of something beautiful

vendor/symfony/password-hasher/Hasher/MigratingPasswordHasher.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\PasswordHasher\Hasher;
+
+use Symfony\Component\PasswordHasher\PasswordHasherInterface;
+
+/**
+ * Hashes passwords using the best available hasher.
+ * Verifies them using a chain of hashers.
+ *
+ * /!\ Don't put a PlaintextPasswordHasher in the list as that'd mean a leaked hash
+ * could be used to authenticate successfully without knowing the cleartext password.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+final class MigratingPasswordHasher implements PasswordHasherInterface
+{
+    private array $extraHashers;
+
+    public function __construct(
+        private PasswordHasherInterface $bestHasher,
+        PasswordHasherInterface ...$extraHashers,
+    ) {
+        $this->extraHashers = $extraHashers;
+    }
+
+    public function hash(#[\SensitiveParameter] string $plainPassword, ?string $salt = null): string
+    {
+        return $this->bestHasher->hash($plainPassword, $salt);
+    }
+
+    public function verify(string $hashedPassword, #[\SensitiveParameter] string $plainPassword, ?string $salt = null): bool
+    {
+        if ($this->bestHasher->verify($hashedPassword, $plainPassword, $salt)) {
+            return true;
+        }
+
+        if (!$this->bestHasher->needsRehash($hashedPassword)) {
+            return false;
+        }
+
+        foreach ($this->extraHashers as $hasher) {
+            if ($hasher->verify($hashedPassword, $plainPassword, $salt)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public function needsRehash(string $hashedPassword): bool
+    {
+        return $this->bestHasher->needsRehash($hashedPassword);
+    }
+}