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Created — forked from dzuelke/bcrypt.php

How to use bcrypt in PHP to safely store passwords (PHP 5.3+ only)

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bcrypt.php
PHP
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<?php
 
// secure hashing of passwords using bcrypt, needs PHP 5.3+
// see http://codahale.com/how-to-safely-store-a-password/
 
// salt for bcrypt needs to be 22 base64 characters (but just [./0-9A-Za-z]), see http://php.net/crypt
// just an example; please use something more secure/random than sha1(microtime) :)
$salt = substr(str_replace('+', '.', base64_encode(sha1(microtime(true), true))), 0, 22);
 
// 2a is the bcrypt algorithm selector, see http://php.net/crypt
// 12 is the workload factor (around 300ms on my Core i7 machine), see http://php.net/crypt
$hash = crypt('foo', '$2a$12$' . $salt);
 
// we can now use the generated hash as the argument to crypt(), since it too will contain $a2$12$... with a variation of the hash. No need to store the salt anymore, just the hash is enough!
var_dump($hash == crypt('foo', $hash)); // true
var_dump($hash == crypt('bar', $hash)); // false
 
?>

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