正文
Yii2有security组件,默认配置在框架底层。
框架削改后,可以在components中自己配置security组件:
"components" => [
'security' => ['class' => 'yii\base\Security'],
]
密码加密:
$hash = Yii::$app->security->generatePasswordHash($password);
验证密码:
// $password 是页面提交的密码,$hash 是上面生成的特征字符串(保存在数据库中)
if (Yii::$app->security->validatePassword($password, $hash)) {
// all good, logging user in
} else {
// wrong password
}
我们看一下yii\base\Security中的几个方法:
/**
* Generates a secure hash from a password and a random salt.
*
* The generated hash can be stored in database.
* Later when a password needs to be validated, the hash can be fetched and passed
* to [[validatePassword()]]. For example,
*
* ```php
* // generates the hash (usually done during user registration or when the password is changed)
* $hash = Yii::$app->getSecurity()->generatePasswordHash($password);
* // ...save $hash in database...
*
* // during login, validate if the password entered is correct using $hash fetched from database
* if (Yii::$app->getSecurity()->validatePassword($password, $hash) {
* // password is good
* } else {
* // password is bad
* }
* ```
*
* @param string $password The password to be hashed.
* @param int $cost Cost parameter used by the Blowfish hash algorithm.
* The higher the value of cost,
* the longer it takes to generate the hash and to verify a password against it. Higher cost
* therefore slows down a brute-force attack. For best protection against brute-force attacks,
* set it to the highest value that is tolerable on production servers. The time taken to
* compute the hash doubles for every increment by one of $cost.
* @return string The password hash string. When [[passwordHashStrategy]] is set to 'crypt',
* the output is always 60 ASCII characters, when set to 'password_hash' the output length
* might increase in future versions of PHP (http://php.net/manual/en/function.password-hash.php)
* @throws Exception on bad password parameter or cost parameter.
* @see validatePassword()
*/
public function generatePasswordHash($password, $cost = null)
{
if ($cost === null) {
$cost = $this->passwordHashCost;
}
if (function_exists('password_hash')) {
/** @noinspection PhpUndefinedConstantInspection */
return password_hash($password, PASSWORD_DEFAULT, ['cost' => $cost]);
}
$salt = $this->generateSalt($cost);
$hash = crypt($password, $salt);
// strlen() is safe since crypt() returns only ascii
if (!is_string($hash) || strlen($hash) !== 60) {
throw new Exception('Unknown error occurred while generating hash.');
}
return $hash;
}
/**
* Generates a salt that can be used to generate a password hash.
*
* The PHP [crypt()](http://php.net/manual/en/function.crypt.php) built-in function
* requires, for the Blowfish hash algorithm, a salt string in a specific format:
* "$2a$", "$2x$" or "$2y$", a two digit cost parameter, "$", and 22 characters
* from the alphabet "./0-9A-Za-z".
*
* @param int $cost the cost parameter
* @return string the random salt value.
* @throws InvalidParamException if the cost parameter is out of the range of 4 to 31.
*/
protected function generateSalt($cost = 13)
{
$cost = (int) $cost;
if ($cost < 4 || $cost > 31) {
throw new InvalidParamException('Cost must be between 4 and 31.');
}
// Get a 20-byte random string
$rand = $this->generateRandomKey(20);
// Form the prefix that specifies Blowfish (bcrypt) algorithm and cost parameter.
$salt = sprintf("$2y$%02d$", $cost);
// Append the random salt data in the required base64 format.
$salt .= str_replace('+', '.', substr(base64_encode($rand), 0, 22));
return $salt;
}
/**
* Generates specified number of random bytes.
* Note that output may not be ASCII.
* @see generateRandomString() if you need a string.
*
* @param int $length the number of bytes to generate
* @return string the generated random bytes
* @throws InvalidParamException if wrong length is specified
* @throws Exception on failure.
*/
public function generateRandomKey($length = 32)
{
if (!is_int($length)) {
throw new InvalidParamException('First parameter ($length) must be an integer');
}
if ($length < 1) {
throw new InvalidParamException('First parameter ($length) must be greater than 0');
}
// always use random_bytes() if it is available
if (function_exists('random_bytes')) {
return random_bytes($length);
}
// The recent LibreSSL RNGs are faster and likely better than /dev/urandom.
// Parse OPENSSL_VERSION_TEXT because OPENSSL_VERSION_NUMBER is no use for LibreSSL.
// https://bugs.php.net/bug.php?id=71143
if ($this->_useLibreSSL === null) {
$this->_useLibreSSL = defined('OPENSSL_VERSION_TEXT')
&& preg_match('{^LibreSSL (\d\d?)\.(\d\d?)\.(\d\d?)$}', OPENSSL_VERSION_TEXT, $matches)
&& (10000 * $matches[1]) + (100 * $matches[2]) + $matches[3] >= 20105;
}
// Since 5.4.0, openssl_random_pseudo_bytes() reads from CryptGenRandom on Windows instead
// of using OpenSSL library. LibreSSL is OK everywhere but don't use OpenSSL on non-Windows.
if ($this->_useLibreSSL
|| (
DIRECTORY_SEPARATOR !== '/'
&& substr_compare(PHP_OS, 'win', 0, 3, true) === 0
&& function_exists('openssl_random_pseudo_bytes')
)
) {
$key = openssl_random_pseudo_bytes($length, $cryptoStrong);
if ($cryptoStrong === false) {
throw new Exception(
'openssl_random_pseudo_bytes() set $crypto_strong false. Your PHP setup is insecure.'
);
}
if ($key !== false && StringHelper::byteLength($key) === $length) {
return $key;
}
}
// mcrypt_create_iv() does not use libmcrypt. Since PHP 5.3.7 it directly reads
// CryptGenRandom on Windows. Elsewhere it directly reads /dev/urandom.
if (function_exists('mcrypt_create_iv')) {
$key = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
if (StringHelper::byteLength($key) === $length) {
return $key;
}
}
// If not on Windows, try to open a random device.
if ($this->_randomFile === null && DIRECTORY_SEPARATOR === '/') {
// urandom is a symlink to random on FreeBSD.
$device = PHP_OS === 'FreeBSD' ? '/dev/random' : '/dev/urandom';
// Check random device for special character device protection mode. Use lstat()
// instead of stat() in case an attacker arranges a symlink to a fake device.
$lstat = @lstat($device);
if ($lstat !== false && ($lstat['mode'] & 0170000) === 020000) {
$this->_randomFile = fopen($device, 'rb') ?: null;
if (is_resource($this->_randomFile)) {
// Reduce PHP stream buffer from default 8192 bytes to optimize data
// transfer from the random device for smaller values of $length.
// This also helps to keep future randoms out of user memory space.
$bufferSize = 8;
if (function_exists('stream_set_read_buffer')) {
stream_set_read_buffer($this->_randomFile, $bufferSize);
}
// stream_set_read_buffer() isn't implemented on HHVM
if (function_exists('stream_set_chunk_size')) {
stream_set_chunk_size($this->_randomFile, $bufferSize);
}
}
}
}
if (is_resource($this->_randomFile)) {
$buffer = '';
$stillNeed = $length;
while ($stillNeed > 0) {
$someBytes = fread($this->_randomFile, $stillNeed);
if ($someBytes === false) {
break;
}
$buffer .= $someBytes;
$stillNeed -= StringHelper::byteLength($someBytes);
if ($stillNeed === 0) {
// Leaving file pointer open in order to make next generation faster by reusing it.
return $buffer;
}
}
fclose($this->_randomFile);
$this->_randomFile = null;
}
throw new Exception('Unable to generate a random key');
}
/**
* Verifies a password against a hash.
* @param string $password The password to verify.
* @param string $hash The hash to verify the password against.
* @return bool whether the password is correct.
* @throws InvalidParamException on bad password/hash parameters or if crypt() with Blowfish hash is not available.
* @see generatePasswordHash()
*/
public function validatePassword($password, $hash)
{
if (!is_string($password) || $password === '') {
throw new InvalidParamException('Password must be a string and cannot be empty.');
}
if (!preg_match('/^\$2[axy]\$(\d\d)\$[\.\/0-9A-Za-z]{22}/', $hash, $matches)
|| $matches[1] < 4
|| $matches[1] > 30
) {
throw new InvalidParamException('Hash is invalid.');
}
if (function_exists('password_verify')) {
return password_verify($password, $hash);
}
$test = crypt($password, $hash);
$n = strlen($test);
if ($n !== 60) {
return false;
}
return $this->compareString($test, $hash);
}
/**
* Performs string comparison using timing attack resistant approach.
* @see http://codereview.stackexchange.com/questions/13512
* @param string $expected string to compare.
* @param string $actual user-supplied string.
* @return bool whether strings are equal.
*/
public function compareString($expected, $actual)
{
$expected .= "\0";
$actual .= "\0";
$expectedLength = StringHelper::byteLength($expected);
$actualLength = StringHelper::byteLength($actual);
$diff = $expectedLength - $actualLength;
for ($i = 0; $i < $actualLength; $i++) {
$diff |= (ord($actual[$i]) ^ ord($expected[$i % $expectedLength]));
}
return $diff === 0;
}
StringHelper::byteLength($string)方法:
/**
* Returns the number of bytes in the given string.
* This method ensures the string is treated as a byte array by using `mb_strlen()`.
* @param string $string the string being measured for length
* @return int the number of bytes in the given string.
*/
public static function byteLength($string)
{
return mb_strlen($string, '8bit');
}
我们看一下Yii2官方推荐的数据库中user表结构:
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
`auth_key` varchar(32) COLLATE utf8_unicode_ci NOT NULL,
`password_hash` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
`password_reset_token` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`email` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
`status` smallint(6) NOT NULL DEFAULT '10',
`created_at` int(11) NOT NULL,
`updated_at` int(11) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `username` (`username`),
UNIQUE KEY `email` (`email`),
UNIQUE KEY `password_reset_token` (`password_reset_token`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
里面auth_key基于cookie登录时使用的认证密钥;password_hash用来登陆;password_reset_token用来取回密码。
其中的原理是:
$auth_key = Yii::$app->security->generateRandomString();
/**
* Generates a random string of specified length.
* The string generated matches [A-Za-z0-9_-]+ and is transparent to URL-encoding.
*
* @param int $length the length of the key in characters
* @return string the generated random key
* @throws Exception on failure.
*/
public function generateRandomString($length = 32)
{
if (!is_int($length)) {
throw new InvalidParamException('First parameter ($length) must be an integer');
}
if ($length < 1) {
throw new InvalidParamException('First parameter ($length) must be greater than 0');
}
$bytes = $this->generateRandomKey($length);
return substr(StringHelper::base64UrlEncode($bytes), 0, $length);
}
$this->generateRandomKey($length)上面有。
参考资料
https://www.yiichina.com/doc/guide/2.0/security-authentication
https://www.yiichina.com/doc/guide/2.0/security-passwords
https://www.yiichina.com/doc/guide/2.0/security-cryptography
Yii2 详说auth_key的用途 https://ibaiyang.github.io/blog/yii2/2017/11/08/Yii2-%E8%AF%A6%E8%AF%B4auth_key%E7%9A%84%E7%94%A8%E9%80%94.html
Yii2 csrf综合 https://ibaiyang.github.io/blog/yii2/2017/12/03/Yii2-csrf%E7%BB%BC%E5%90%88.html