PHP Requires Chilkat v11.6.0+

Hash a Password with Argon2 (Defaults)

Demonstrates Crypt2.Argon2HashPassword, which hashes a password with Argon2 and returns a PHC-format string. Passing an empty options string uses all defaults, including a random salt.

Background. Argon2 (RFC 9106) is a memory-hard function that is deliberately expensive in CPU time and memory, which is what makes brute-forcing the password space costly. The argon2id variant is recommended unless there is a specific reason to choose argon2i or argon2d. The returned PHC string records the variant, version, cost parameters, salt, and hash — everything needed to verify the password later. Store the whole string.

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<?php

use Chilkat2\Crypt2;

$crypt = new Crypt2();

// The password should come from a secure source rather than being hard-coded.
$password = 'correct horse battery staple';

// Hash the password using all defaults by passing an empty options string.  The defaults are
// Argon2id, version 19, 3 iterations, 64 MB of memory, 1 lane, a 32-byte hash, and a 16-byte random
// salt.  A random salt is generated automatically, which is what should normally happen.
try {
    $phcHash = $crypt->Argon2HashPassword($password, '');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// The returned PHC-format string records the variant, version, cost parameters, salt, and hash --
// everything needed to verify the password later.  Store the whole string.
echo $phcHash, "\n";