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--- rfc:hash_pbkdf2 [2012/07/02 16:32] – Open voting for hash_pbkdf2 ircmaxell
+++ rfc:hash_pbkdf2 [2012/07/02 16:49] – Add 2 examples ircmaxell
@@ Line 57: / Line 57: @@
 This parameter behaves just like the other *hash_* functions. If set to *true*, the function will return a binary string (chr 0-255). If set to *false*, the function will hex encode the result prior to returning it.
+===== Example =====
+Let's say you wanted to encrypt a file using a password. The password shouldn't be applied directly to the encryption function, but should be derived first.
+<file php encryption.php>
+<?php
+$password = "foo";
+$data = "testing this out";
+$salt = mcrypt_create_iv(16, MCRYPT_DEV_URANDOM);
+$key = hash_pbkdf2("sha512", $password, $salt, 5000, 16, true);
+// $key will be full-byte 0-255 data
+$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC), MCRYPT_DEV_URANDOM);
+$ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $data, MCRYPT_MODE_CBC, $iv);
+?>
+</file>
+Or for storing passwords (BCrypt is recommended, but there are use-cases for PBKDF2, such as when NIST compliance is mandated):
+<file php password.php>
+<?php
+$password = "foo";
+$salt = mcrypt_create_iv(16, MCRYPT_DEV_URANDOM);
+$hash = hash_pbkdf2("sha512", $password, $salt, 5000, 32);
+// $hash will be a hex encoded string
+?>
+</file>
 ===== Proposal and Patch =====