silverstripe-framework/security/PasswordEncryptor.php
2012-11-09 12:03:55 +01:00

241 lines
6.4 KiB
PHP

<?php
/**
* Allows pluggable password encryption.
* By default, this might be PHP's integrated sha1()
* function, but could also be more sophisticated to facilitate
* password migrations from other systems.
* Use {@link register()} to add new implementations.
*
* Used in {@link Security::encrypt_password()}.
*
* @package sapphire
* @subpackage security
*/
abstract class PasswordEncryptor {
/**
* @var array
*/
protected static $encryptors = array();
/**
* @return Array Map of encryptor code to the used class.
*/
static function get_encryptors() {
return self::$encryptors;
}
/**
* Add a new encryptor implementation.
*
* Note: Due to portability concerns, its not advisable to
* override an existing $code mapping with different behaviour.
*
* @param String $code This value will be stored stored in the
* {@link Member->PasswordEncryption} property.
* @param String $class Classname of a {@link PasswordEncryptor} subclass
*/
static function register($code, $class) {
self::$encryptors[$code] = $class;
}
/**
* @param String $code Unique lookup.
*/
static function unregister($code) {
if(isset(self::$encryptors[$code])) unset(self::$encryptors[$code]);
}
/**
* @param String $algorithm
* @return PasswordEncryptor|Boolean Returns FALSE if class was not found
*/
static function create_for_algorithm($algorithm) {
if(!isset(self::$encryptors[$algorithm])) {
throw new PasswordEncryptor_NotFoundException(
sprintf('No implementation found for "%s"', $algorithm)
);
}
$classWithArgs = self::$encryptors[$algorithm];
$class = (($p = strpos($classWithArgs, '(')) !== false) ? substr($classWithArgs, 0, $p) : $classWithArgs;
if(!class_exists($class)) {
throw new PasswordEncryptor_NotFoundException(
sprintf('No class found for "%s"', $class)
);
}
return eval("return new $classWithArgs;");
}
/**
* Return a string value stored in the {@link Member->Password} property.
* The password should be hashed with {@link salt()} if applicable.
*
* @param String $password Cleartext password to be hashed
* @param String $salt (Optional)
* @param Member $member (Optional)
* @return String Maximum of 512 characters.
*/
abstract function encrypt($password, $salt = null, $member = null);
/**
* Return a string value stored in the {@link Member->Salt} property.
* Note: Only used when {@link Security::$useSalt} is TRUE.
*
* @uses RandomGenerator
*
* @param String $password Cleartext password
* @param Member $member (Optional)
* @return String Maximum of 50 characters
*/
function salt($password, $member = null) {
$generator = new RandomGenerator();
return substr($generator->randomToken('sha1'), 0, 50);
}
/**
* This usually just returns a strict string comparison,
* but is necessary for {@link PasswordEncryptor_LegacyPHPHash}.
*
* @param String $hash1
* @param String $hash2
* @return boolean
*/
function compare($hash1, $hash2) {
return ($hash1 === $hash2);
}
}
/**
* This is the default class used for built-in hash types in PHP.
* Please note that the implemented algorithms depend on the PHP
* distribution and architecture.
*
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_PHPHash extends PasswordEncryptor {
protected $algorithm = 'sha1';
/**
* @param String $algorithm A PHP built-in hashing algorithm as defined by hash_algos()
*/
function __construct($algorithm) {
if(!in_array($algorithm, hash_algos())) {
throw new Exception(
sprintf('Hash algorithm "%s" not found in hash_algos()', $algorithm)
);
}
$this->algorithm = $algorithm;
}
/**
* @return string
*/
function getAlgorithm() {
return $this->algorithm;
}
function encrypt($password, $salt = null, $member = null) {
if(function_exists('hash')) {
// Available in PHP 5.1+ only
return hash($this->algorithm, $password . $salt);
} else {
// Fallback to global built-in methods
return call_user_func($this->algorithm, $password . $salt);
}
}
}
/**
* Legacy implementation for SilverStripe 2.1 - 2.3,
* which had a design flaw in password hashing that caused
* the hashes to differ between architectures due to
* floating point precision problems in base_convert().
* See http://open.silverstripe.org/ticket/3004
*
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_LegacyPHPHash extends PasswordEncryptor_PHPHash {
function encrypt($password, $salt = null, $member = null) {
$password = parent::encrypt($password, $salt, $member);
// Legacy fix: This shortening logic is producing unpredictable results.
//
// Convert the base of the hexadecimal password to 36 to make it shorter
// In that way we can store also a SHA256 encrypted password in just 64
// letters.
return substr(base_convert($password, 16, 36), 0, 64);
}
function compare($hash1, $hash2) {
// Due to flawed base_convert() floating poing precision,
// only the first 10 characters are consistently useful for comparisons.
return (substr($hash1, 0, 10) === substr($hash2, 0, 10));
}
}
/**
* Uses MySQL's PASSWORD encryption. Requires an active DB connection.
*
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_MySQLPassword extends PasswordEncryptor {
function encrypt($password, $salt = null, $member = null) {
return DB::query(
sprintf("SELECT PASSWORD('%s')", Convert::raw2sql($password))
)->value();
}
function salt($password, $member = null) {
return false;
}
}
/**
* Uses MySQL's OLD_PASSWORD encyrption. Requires an active DB connection.
*
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_MySQLOldPassword extends PasswordEncryptor {
function encrypt($password, $salt = null, $member = null) {
return DB::query(
sprintf("SELECT OLD_PASSWORD('%s')", Convert::raw2sql($password))
)->value();
}
function salt($password, $member = null) {
return false;
}
}
/**
* Cleartext passwords (used in SilverStripe 2.1).
* Also used when Security::$encryptPasswords is set to FALSE.
* Not recommended.
*
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_None extends PasswordEncryptor {
function encrypt($password, $salt = null, $member = null) {
return $password;
}
function salt($password, $member = null) {
return false;
}
}
/**
* @package sapphire
* @subpackage security
*/
class PasswordEncryptor_NotFoundException extends Exception {}