Generates cryptographically secure pseudo-random bytes

Description

string random_bytes ( int $length )

Generates an arbitrary length string of cryptographic random bytes that are suitable for use in cryptography when generating salts, keys and initialization vectors.

The sources of random are as follows:

On Windows CryptGenRandom() is used exclusively
arc4random_buf() is used if it is available (generally BSD specific)
/dev/arandom is used where available
/dev/urandom is used where none of the above is available

Parameters

length: The length of the random string that should be returned in bytes.

Return Values

Returns a string containing the crypto-secure random bytes in binary format.

Errors/Exceptions

Issues an E_WARNING and returns FALSE when a sufficient source of randomness is unavailable.

Examples

Example #1 random-bytes() example


<?php
$bytes = random_bytes(5);
var_dump(bin2hex($bytes));
?>

The above example will output something similar to:

string(10) "385e33f741"

random_bytes

Description

Parameters

Return Values

Errors/Exceptions

Examples

See Also