(PHP 7, PHP 8)
random_bytes — Generates cryptographically secure pseudo-random bytes
$length
): string
Generates an arbitrary length string of cryptographic random bytes that are suitable for cryptographic use, such as when generating salts, keys or initialization vectors.
此函数使用的随机性来源如下:
注意: 虽然此函数是 PHP 7.0 添加到 PHP 中,但是从 PHP 5.2 到 PHP 5.6 都可以用 » 用户级实现。
length
The length of the random string that should be returned in bytes; must be 1
or greater.
A string containing the requested number of cryptographically secure random bytes.
length
is less than 1
,
a ValueError will be thrown.
版本 | 说明 |
---|---|
8.2.0 | In case of a CSPRNG failure, this function will now throw a Random\RandomException. Previously a plain Exception was thrown. |
示例 #1 random_bytes() example
<?php
$bytes = random_bytes(5);
var_dump(bin2hex($bytes));
?>
以上例程的输出类似于:
string(10) "385e33f741"