crypt_gensalt

(PECL xpass >= 1.1.0)

crypt_gensalt — Compile a string for use as the salt argument to crypt

説明

function crypt_gensalt(string $prefix = null, int $count = 0): ?string

Compile a string for use as the salt argument to crypt().

パラメータ

prefix: Hashing method. One of the CRYPT_PREFIX_* constant. If null, the best available hashing method will be selected.
count: Controls the processing cost of the hash; the valid range and exact meaning of count depend on the hashing method, but larger numbers correspond to more costly hashes in terms of CPU time and possibly memory usage. If count is 0, a low default cost will be selected.

戻り値

Returns a string with the setting, or null in case of an error.

例

例1 A crypt_gensalt() example

<?php
// Generate the salt
$salt = crypt_gensalt(CRYPT_PREFIX_BLOWFISH);
// Hash the password
$hash = crypt("secret", $salt);
// Check the hash
$test = hash_equals(crypt("secret", $hash), $hash);
var_dump($salt, $hash, $test);
?>

上の例の出力は以下となります。

string(29) "$2y$05$GcPykP.Am8C1.dGamdpwW."
string(60) "$2y$05$GcPykP.Am8C1.dGamdpwW.1RR.7uicWvJPZfJfCEizZHqVWwuaJLm"
bool(true)

参考

crypt_preferred_method() - Get the prefix of the preferred hash method
crypt() - 文字列の一方向のハッシュ化を行う
hash_equals() - タイミング攻撃に対しても安全な文字列比較

関連キーワード:

crypt hash salt method gensalt Compile argument count preferred prefix hashing selected cost secret equals GcPykP dGamdpwW checksalt Xpass xpass Hashing constant best available Controls