icingaweb2/library/Icinga/Authentication/PasswordHelper.php

110 lines
2.7 KiB
PHP

<?php
/* Icinga Web 2 | (c) 2017 Icinga Development Team | GPLv2+ */
namespace Icinga\Authentication;
use Icinga\Exception\AuthenticationException;
/**
* Helper for password hashing to improve compatibility to PHP < 5.5
*/
class PasswordHelper
{
/**
* The PHP version that introduced support for functions:
*
* password_hash()
* password_verify()
*
* @var string
*/
const PHP_VERSION_COMPAT = '5.5.0';
/**
* Algo to force fallback to compat algorithm
*/
const PASSWORD_ALGO_FALLBACK = 999;
/**
* The length of the salt to use when hashing a password with SHA method
*
* 16 is the required character count
*
* @var int
*/
const COMPAT_SALT_LENGTH = 16;
/**
* Hash type to use as compat method: SHA-512
*
* @var string
*/
const COMPAT_HASH = '$6$rounds=5000$';
/**
* Check if we have a modern PHP based on version
*
* @return bool
*/
public static function supportsModernAPI()
{
return version_compare(phpversion(), self::PHP_VERSION_COMPAT, '>=');
}
/**
* Hash a password with password_hash() or crypt()
*
* @param string $password
* @param int $algo
*
* @return string
* @throws AuthenticationException
*/
public static function hash($password, $algo = null)
{
if (static::supportsModernAPI() and $algo !== self::PASSWORD_ALGO_FALLBACK) {
if ($algo === null) {
$algo = PASSWORD_DEFAULT;
}
$p = password_hash($password, $algo);
if ($p === false) {
throw new AuthenticationException('Could not hash password, password_hash() returned false!');
}
} else {
$p = crypt($password, self::COMPAT_HASH . static::generateSalt());
if (strlen($p) < 13) {
throw new AuthenticationException('Hash generated by crypt() seems too small, this suggests an error!');
}
}
return $p;
}
/**
* Verify a password with either password_verify() or crypt()
*
* @param string $password
* @param string $hash
*
* @return bool
*/
public static function verify($password, $hash)
{
if (static::supportsModernAPI()) {
return password_verify($password, $hash);
} else {
return crypt($password, $hash) === $hash;
}
}
/**
* Shorthand to generate a salt to use with crypt()
*
* @return string
*/
public static function generateSalt()
{
return bin2hex(openssl_random_pseudo_bytes(self::COMPAT_SALT_LENGTH / 2));
}
}