PHP - Hash equals() Function

Definition and Usage

The hash_equals() function compares two given strings at the same time and return true if equal.

Syntax

hash_equals ( string $known_string , string $user_string ) : bool

Parameters

Return Values

PHP hash_equals() function returns a boolean i.e true if the strings are equal and false if not.

PHP Version

This function will work from PHP Version greater than 5.6.0.

Example 1

Working of hash_equals() −

<?php
   $known_str = crypt('tutorialspoint','$5$rounds=1000$salttest$');
   $usr_str   = crypt('tutorialspoint','$5$rounds=1000$salttest$');
   $res = hash_equals($known_str, $usr_str); 
   var_dump($res);
?>

Output

This will produce the following result −

bool(true)

Example 2

Comparing hash using hash_equals −

<?php
   $known_str = crypt('tutorialspoint','$5$rounds=1000$salttest$');
   $usr_str   = crypt('helloworld','$5$rounds=1000$salttest$');
   $res = hash_equals($known_str, $usr_str); 
   var_dump($res);
?>

Output

This will produce the following result −

bool(false)

Example 3

Comparing hash from hash() and hash_file() −

<?php
   $hash1 = hash("md5", 'Welcome to Tutorialspoint');
   file_put_contents('filetest.txt', 'Welcome to Tutorialspoint'); 
   // create file filetest.txt with content : 'Welcome to Tutorialspoint'
   $hash2 = hash_file('md5', 'filetest.txt');
   $_compare = hash_equals($hash1, $hash2); 
   var_dump($_compare);
?>

Output

This will produce the following result −

bool(true)