--- /dev/null
+<?php
+/**
+ * An implementation of the RFC 2898 PBKDF1 Standard key derivation function
+ *
+ * PHP version 5.3
+ *
+ * @see http://www.ietf.org/rfc/rfc2898.txt
+ * @category PHPCryptLib
+ * @package Key
+ * @subpackage Derivation
+ * @author Anthony Ferrara <ircmaxell@ircmaxell.com>
+ * @copyright 2011 The Authors
+ * @license http://www.opensource.org/licenses/mit-license.html MIT License
+ * @version Build @@version@@
+ */
+
+namespace CryptLib\Key\Derivation\PBKDF;
+
+use CryptLib\Hash\Hash;
+
+/**
+ * An implementation of the RFC 2989 PBKDF1 Standard key derivation function
+ *
+ * @see http://www.ietf.org/rfc/rfc2898.txt
+ * @category PHPCryptLib
+ * @package Key
+ * @subpackage Derivation
+ * @author Anthony Ferrara <ircmaxell@ircmaxell.com>
+ */
+class PBKDF1
+ extends \CryptLib\Key\Derivation\AbstractDerivation
+ implements \CryptLib\Key\Derivation\PBKDF
+{
+
+ /**
+ * Derive a key from the supplied arguments
+ *
+ * @param string $password The password to derive from
+ * @param string $salt The salt string to use
+ * @param int $iterations The number of iterations to use
+ * @param int $length The size of the string to generate
+ *
+ * @return string The derived key
+ */
+ public function derive($password, $salt, $iterations, $length) {
+ $size = Hash::getHashSize($this->hash);
+ if ($length > $size) {
+ $message = 'Length is too long for hash';
+ throw new \InvalidArgumentException($message);
+ }
+ $tmp = hash($this->hash, $password . $salt, true);
+ for ($i = 2; $i <= $iterations; $i++) {
+ $tmp = hash($this->hash, $tmp, true);
+ }
+ return substr($tmp, 0, $length);
+ }
+
+ /**
+ * Get the signature for this implementation
+ *
+ * This should include all information needed to build the same isntance
+ * later.
+ *
+ * @return string The signature for this instance
+ */
+ public function getSignature() {
+ return 'pbkdf1-' . $this->hash;
+ }
+
+}
+