openssl_pbkdf2()

(PHP 5 >= 5.5.0, PHP 7)

生成一个 PKCS5 v2 PBKDF2 字符串

说明

openssl_pbkdf2(string $password,string $salt,int $key_length,int $iterations[,string $digest_algorithm= "sha1"]): string

openssl_pbkdf2()计算 PBKDF2(Password-Based Key Derivation Function 2),在PKCS5 v2中定义的一个密钥的推导函数.

参数

$password: 派生密钥所生成的密码。
$salt: PBKDF2 推荐一个不少于64位(8字节)的密码盐值。
$key_length: 希望输出密钥的长度。
$iterations: 需要的迭代次数» NIST 建议至少10,000次.
$digest_algorithm: 在openssl_get_md_methods()中可选的散列或摘要算法.默认是 SHA-1.

返回值

成功，返回原始二进制字符串或者在失败时返回FALSE.

范例

openssl_pbkdf2()范例

<?php
$password = 'yOuR-pAs5w0rd-hERe';
$salt = openssl_random_pseudo_bytes(12);
$keyLength = 40;
$iterations = 10000;
$generated_key = openssl_pbkdf2($password, $salt, $keyLength, $iterations, 'sha256');
echo bin2hex($generated_key)."\n";
echo base64_encode($generated_key)."\n";
?>

参见

hash_pbkdf2()生成所提供密码的 PBKDF2 密钥导出
openssl_get_md_methods()获取可用的摘要算法

Despite the manual claiming that this is available in PHP 5.5 and above, this function wasn't made available in my local install.
I expect that having a prehistoric OpenSSL library version installed is the likely culprit.
If you're using PHP 5.5 and don't have this function available in your OpenSSL extension, look at the functionally equivalent hash_pbkdf2 function instead.