random_bytes — Generates cryptographically secure pseudo-random bytes
Generates an arbitrary length string of cryptographic random bytes that are suitable for cryptographic use, such as when generating salts, keys or initialization vectors.
The sources of randomness used for this function are as follows:
Note: Although this function was added to PHP in PHP 7.0, a » userland implementation is available for PHP 5.2 to 5.6, inclusive.
The length of the random string that should be returned in bytes.
Returns a string containing the requested number of cryptographically secure random bytes.
lengthof bytes is given, an Error will be thrown.
Example #1 random_bytes() example
$bytes = random_bytes(5);