PHP マニュアル: Compile a string for use as the salt argument to crypt

説明

stringnull crypt_gensalt(string $prefix = null, int $count = 0)

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
crypt
hash_equals