Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

<?php

include("chilkat.php");

$crypt = new CkCrypt2();

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

//  The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
//  hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
//  sets how many random bytes to use.
$json = new CkJsonObject();
$json->UpdateString('variant','argon2id');
$json->UpdateInt('memoryCostKb',131072);
$json->UpdateInt('iterations',4);
$json->UpdateInt('parallelism',2);
$json->UpdateInt('saltLen',16);

//  A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
//  same values must be supplied to Argon2VerifyPassword for the password to verify.
$json->UpdateString('secret','application-wide-pepper');
$json->UpdateString('secretEncoding','utf-8');

$phcHash = $crypt->argon2HashPassword($password,$json->emit());
if ($crypt->get_LastMethodSuccess() == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print $phcHash . "\n";

?>