silverstripe-framework/security/PasswordEncryptor.php
2012-05-16 16:40:12 +12:00

406 lines
12 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 framework
* @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 Config::inst()->get('PasswordEncryptor', '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, $class) {
Deprecation::notice('3.0', 'Use the Config system to register Password encryptors');
self::$encryptors[$code] = $class;
}
/**
* @param String $code Unique lookup.
*/
static function unregister($code) {
Deprecation::notice('3.0', 'Use the Config system to unregister Password encryptors');
if(isset(self::$encryptors[$code])) unset(self::$encryptors[$code]);
}
/**
* @param String $algorithm
* @return PasswordEncryptor
* @throws PasswordEncryptor_NotFoundException
*/
static function create_for_algorithm($algorithm) {
$encryptors = self::get_encryptors();
if(!isset($encryptors[$algorithm])) {
throw new PasswordEncryptor_NotFoundException(
sprintf('No implementation found for "%s"', $algorithm)
);
}
$class=key($encryptors[$algorithm]);
if(!class_exists($class)) {
throw new PasswordEncryptor_NotFoundException(
sprintf('No class found for "%s"', $class)
);
}
$refClass = new ReflectionClass($class);
if(!$refClass->getConstructor()) {
return new $class;
}
$arguments = $encryptors[$algorithm];
return($refClass->newInstanceArgs($arguments));
}
/**
* 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.
*
* @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->generateHash('sha1'), 0, 50);
}
/**
* This usually just returns a strict string comparison,
* but is necessary for {@link PasswordEncryptor_LegacyPHPHash}.
*
* @param String $hash1
* @param String $hash2
* @return boolean
*
* @deprecated 3.0 - Use PasswordEncryptor::check() instead.
*/
function compare($hash1, $hash2) {
Deprecation::notice('3.0.0', 'PasswordEncryptor::compare() is deprecated, replaced by PasswordEncryptor::check().');
return ($hash1 === $hash2);
}
/**
* This usually just returns a strict string comparison,
* but is necessary for retain compatibility with password hashed
* with flawed algorithms - see {@link PasswordEncryptor_LegacyPHPHash} and
* {@link PasswordEncryptor_Blowfish}
*/
function check($hash, $password, $salt = null, $member = null) {
return $hash === $this->encrypt($password, $salt, $member);
}
}
/**
* Blowfish encryption - this is the default from SilverStripe 3.
* PHP 5.3+ will provide a php implementation if there is no system
* version available.
*
* @package framework
* @subpackage security
*/
class PasswordEncryptor_Blowfish extends PasswordEncryptor {
/**
* Cost of encryption.
* Higher costs will increase security, but also increase server load.
* If you are using basic auth, you may need to decrease this as encryption
* will be run on every request.
* Must be between 4 and 31.
*/
protected static $cost = 10;
function encrypt($password, $salt = null, $member = null) {
// See: http://nz.php.net/security/crypt_blowfish.php
// There are three version of the algorithm - y, a and x, in order
// of decreasing security. Attempt to use the strongest version.
$encryptedPassword = $this->encryptY($password, $salt);
if(!$encryptedPassword) {
$encryptedPassword = $this->encryptA($password, $salt);
}
if(!$encryptedPassword) {
$encryptedPassword = $this->encryptX($password, $salt);
}
// We *never* want to generate blank passwords. If something
// goes wrong, throw an exception.
if(strpos($encryptedPassword, '$2') === false) {
throw new PasswordEncryptor_EncryptionFailed('Blowfish password encryption failed.');
}
return $encryptedPassword;
}
function encryptX($password, $salt) {
$methodAndSalt = '$2x$' . $salt;
$encryptedPassword = crypt($password, $methodAndSalt);
if(strpos($encryptedPassword, '$2x$') === 0) {
return $encryptedPassword;
}
// Check if system a is actually x, and if available, use that.
if($this->checkAEncryptionLevel() == 'x') {
$methodAndSalt = '$2a$' . $salt;
$encryptedPassword = crypt($password, $methodAndSalt);
if(strpos($encryptedPassword, '$2a$') === 0) {
$encryptedPassword = '$2x$' . substr($encryptedPassword, strlen('$2a$'));
return $encryptedPassword;
}
}
return false;
}
function encryptY($password, $salt) {
$methodAndSalt = '$2y$' . $salt;
$encryptedPassword = crypt($password, $methodAndSalt);
if(strpos($encryptedPassword, '$2y$') === 0) {
return $encryptedPassword;
}
// Check if system a is actually y, and if available, use that.
if($this->checkAEncryptionLevel() == 'y') {
$methodAndSalt = '$2a$' . $salt;
$encryptedPassword = crypt($password, $methodAndSalt);
if(strpos($encryptedPassword, '$2a$') === 0) {
$encryptedPassword = '$2y$' . substr($encryptedPassword, strlen('$2a$'));
return $encryptedPassword;
}
}
return false;
}
function encryptA($password, $salt) {
if($this->checkAEncryptionLevel() == 'a') {
$methodAndSalt = '$2a$' . $salt;
$encryptedPassword = crypt($password, $methodAndSalt);
if(strpos($encryptedPassword, '$2a$') === 0) {
return $encryptedPassword;
}
}
return false;
}
/**
* The algorithm returned by using '$2a$' is not consistent -
* it might be either the correct (y), incorrect (x) or mostly-correct (a)
* version, depending on the version of PHP and the operating system,
* so we need to test it.
*/
function checkAEncryptionLevel() {
// Test hashes taken from http://cvsweb.openwall.com/cgi/cvsweb.cgi/~checkout~/Owl/packages/glibc/crypt_blowfish/wrapper.c?rev=1.9.2.1;content-type=text%2Fplain
$xOrY = crypt("\xff\xa334\xff\xff\xff\xa3345", '$2a$05$/OK.fbVrR/bpIqNJ5ianF.o./n25XVfn6oAPaUvHe.Csk4zRfsYPi') == '$2a$05$/OK.fbVrR/bpIqNJ5ianF.o./n25XVfn6oAPaUvHe.Csk4zRfsYPi';
$yOrA = crypt("\xa3", '$2a$05$/OK.fbVrR/bpIqNJ5ianF.Sa7shbm4.OzKpvFnX1pQLmQW96oUlCq') == '$2a$05$/OK.fbVrR/bpIqNJ5ianF.Sa7shbm4.OzKpvFnX1pQLmQW96oUlCq';
if($xOrY && $yOrA) {
return 'y';
} elseif($xOrY) {
return 'x';
} elseif($yOrA) {
return 'a';
}
return 'unknown';
}
function salt($password, $member = null) {
$generator = new RandomGenerator();
return self::$cost . '$' . substr($generator->generateHash('sha1'), 0, 22);
}
function check($hash, $password, $salt = null, $member = null) {
if(strpos($hash, '$2y$') === 0) {
return $hash === $this->encryptY($password, $salt);
} elseif(strpos($hash, '$2a$') === 0) {
return $hash === $this->encryptA($password, $salt);
} elseif(strpos($hash, '$2x$') === 0) {
return $hash === $this->encryptX($password, $salt);
}
return false;
}
}
/**
* Encryption using built-in hash types in PHP.
* Please note that the implemented algorithms depend on the PHP
* distribution and architecture.
*
* @package framework
* @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, $member = null) {
return hash($this->algorithm, $password . $salt);
}
}
/**
* Legacy implementation for SilverStripe 2.1 - 2.3,
* which had a design flaw in password hashing that caused
* the hashes to differ between architectures due to
* floating point precision problems in base_convert().
* See http://open.silverstripe.org/ticket/3004
*
* @package framework
* @subpackage security
*/
class PasswordEncryptor_LegacyPHPHash extends PasswordEncryptor_PHPHash {
function encrypt($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, $hash2) {
Deprecation::notice('3.0.0', 'PasswordEncryptor::compare() is deprecated, replaced by PasswordEncryptor::check().');
// Due to flawed base_convert() floating poing precision,
// only the first 10 characters are consistently useful for comparisons.
return (substr($hash1, 0, 10) === substr($hash2, 0, 10));
}
function check($hash, $password, $salt = null, $member = null) {
// Due to flawed base_convert() floating poing precision,
// only the first 10 characters are consistently useful for comparisons.
return (substr($hash, 0, 10) === substr($this->encrypt($password, $salt, $member), 0, 10));
}
}
/**
* Uses MySQL's PASSWORD encryption. Requires an active DB connection.
*
* @package framework
* @subpackage security
*/
class PasswordEncryptor_MySQLPassword extends PasswordEncryptor {
function encrypt($password, $salt = null, $member = null) {
return DB::query(
sprintf("SELECT PASSWORD('%s')", Convert::raw2sql($password))
)->value();
}
function salt($password, $member = null) {
return false;
}
}
/**
* Uses MySQL's OLD_PASSWORD encyrption. Requires an active DB connection.
*
* @package framework
* @subpackage security
*/
class PasswordEncryptor_MySQLOldPassword extends PasswordEncryptor {
function encrypt($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 framework
* @subpackage security
*/
class PasswordEncryptor_None extends PasswordEncryptor {
function encrypt($password, $salt = null, $member = null) {
return $password;
}
function salt($password, $member = null) {
return false;
}
}
/**
* @package framework
* @subpackage security
*/
class PasswordEncryptor_NotFoundException extends Exception {}
/**
* @package framework
* @subpackage security
*/
class PasswordEncryptor_EncryptionFailed extends Exception {}