PHP | random_bytes () Function
The random_bytes()is an inbuilt function in PHP. The main function is to generate cryptographically secure pseudo-random bytes. It generates cryptographic random bytes of arbitrary string length. The different sources of randomness used in this function, they are as follows:-
- Window : CryptGenRandom() function.
- Linux : getrandom(2) system call function.
Syntax :
String random_bytes ( int $length )
Parameter : It is the length of random string, returned in bytes. Return Value: The function returns the cryptographically secure random bytes in string. Examples:
Input : length = 7 Output :string(14) "cbd392c01352b0"
Below programs illustrate the random_bytes () function in PHP. Program 1:
php
<?php //random_bytes () function in PHP $length = random_bytes( '4' ); //Print the result and convert by binaryhexa var_dump(bin2hex( $length )); ?> |
Output:
string(8) "e62a94a2"
php
<?php //random_bytes () function in PHP $length = random_bytes( '6' ); //Print the result and convert by binaryhexa var_dump(bin2hex( $length )); ?> |
Output:
string(12) "808fc44d325b"
Exception Error :
- Invalid parameter will give TypeError .
- Invalid length of bytes gives Error.
- If source of randomness is not found then Exception will be thrown.
References: http://php.net/manual/en/function.random-bytes.php
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