<?php
/**
* Pure-PHP implementation of ChaCha20.
*
* PHP version 5
*
* @author Jim Wigginton <terrafrost@php.net>
* @copyright 2019 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib3\Crypt;
use phpseclib3\Exception\BadDecryptionException;
use phpseclib3\Exception\InsufficientSetupException;
/**
* Pure-PHP implementation of ChaCha20.
*
* @author Jim Wigginton <terrafrost@php.net>
*/
class ChaCha20 extends Salsa20
{
/**
* The OpenSSL specific name of the cipher
*
* @var string
*/
protected $cipher_name_openssl = 'chacha20';
/**
* Test for engine validity
*
* This is mainly just a wrapper to set things up for \phpseclib3\Crypt\Common\SymmetricKey::isValidEngine()
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::__construct()
* @param int $engine
* @return bool
*/
protected function isValidEngineHelper($engine)
{
switch ($engine) {
case self::ENGINE_LIBSODIUM:
// PHP 7.2.0 (30 Nov 2017) added support for libsodium
// we could probably make it so that if $this->counter == 0 then the first block would be done with either OpenSSL
// or PHP and then subsequent blocks would then be done with libsodium but idk - it's not a high priority atm
// we could also make it so that if $this->counter == 0 and $this->continuousBuffer then do the first string
// with libsodium and subsequent strings with openssl or pure-PHP but again not a high priority
return function_exists('sodium_crypto_aead_chacha20poly1305_ietf_encrypt') &&
$this->key_length == 32 &&
(($this->usePoly1305 && !isset($this->poly1305Key) && $this->counter == 0) || $this->counter == 1) &&
!$this->continuousBuffer;
case self::ENGINE_OPENSSL:
// OpenSSL 1.1.0 (released 25 Aug 2016) added support for chacha20.
// PHP didn't support OpenSSL 1.1.0 until 7.0.19 (11 May 2017)
// if you attempt to provide openssl with a 128 bit key (as opposed to a 256 bit key) openssl will null
// pad the key to 256 bits and still use the expansion constant for 256-bit keys. the fact that
// openssl treats the IV as both the counter and nonce, however, let's us use openssl in continuous mode
// whereas libsodium does not
if ($this->key_length != 32) {
return false;
}
}
return parent::isValidEngineHelper($engine);
}
/**
* Encrypts a message.
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt()
* @see self::crypt()
* @param string $plaintext
* @return string $ciphertext
*/
public function encrypt($plaintext)
{
$this->setup();
if ($this->engine == self::ENGINE_LIBSODIUM) {
return $this->encrypt_with_libsodium($plaintext);
}
return parent::encrypt($plaintext);
}
/**
* Decrypts a message.
*
* $this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)).
* At least if the continuous buffer is disabled.
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt()
* @see self::crypt()
* @param string $ciphertext
* @return string $plaintext
*/
public function decrypt($ciphertext)
{
$this->setup();
if ($this->engine == self::ENGINE_LIBSODIUM) {
return $this->decrypt_with_libsodium($ciphertext);
}
return parent::decrypt($ciphertext);
}
/**
* Encrypts a message with libsodium
*
* @see self::encrypt()
* @param string $plaintext
* @return string $text
*/
private function encrypt_with_libsodium($plaintext)
{
$params = [$plaintext, $this->aad, $this->nonce, $this->key];
$ciphertext = strlen($this->nonce) == 8 ?
sodium_crypto_aead_chacha20poly1305_encrypt(...$params) :
sodium_crypto_aead_chacha20poly1305_ietf_encrypt(...$params);
if (!$this->usePoly1305) {
return substr($ciphertext, 0, strlen($plaintext));
}
$newciphertext = substr($ciphertext, 0, strlen($plaintext));
$this->newtag = $this->usingGeneratedPoly1305Key && strlen($this->nonce) == 12 ?
substr($ciphertext, strlen($plaintext)) :
$this->poly1305($newciphertext);
return $newciphertext;
}
/**
* Decrypts a message with libsodium
*
* @see self::decrypt()
* @param string $ciphertext
* @return string $text
*/
private function decrypt_with_libsodium($ciphertext)
{
$params = [$ciphertext, $this->aad, $this->nonce, $this->key];
if (isset($this->poly1305Key)) {
if ($this->oldtag === false) {
throw new InsufficientSetupException('Authentication Tag has not been set');
}
if ($this->usingGeneratedPoly1305Key && strlen($this->nonce) == 12) {
$plaintext = sodium_crypto_aead_chacha20poly1305_ietf_decrypt(...$params);
$this->oldtag = false;
if ($plaintext === false) {
throw new BadDecryptionException('Derived authentication tag and supplied authentication tag do not match');
}
return $plaintext;
}
$newtag = $this->poly1305($ciphertext);
if ($this->oldtag != substr($newtag, 0, strlen($this->oldtag))) {
$this->oldtag = false;
throw new BadDecryptionException('Derived authentication tag and supplied authentication tag do not match');
}
$this->oldtag = false;
}
$plaintext = strlen($this->nonce) == 8 ?
sodium_crypto_aead_chacha20poly1305_encrypt(...$params) :
sodium_crypto_aead_chacha20poly1305_ietf_encrypt(...$params);
return substr($plaintext, 0, strlen($ciphertext));
}
/**
* Sets the nonce.
*
* @param string $nonce
*/
public function setNonce($nonce)
{
if (!is_string($nonce)) {
throw new \UnexpectedValueException('The nonce should be a string');
}
/*
from https://tools.ietf.org/html/rfc7539#page-7
"Note also that the original ChaCha had a 64-bit nonce and 64-bit
block count. We have modified this here to be more consistent with
recommendations in Section 3.2 of [RFC5116]."
*/
switch (strlen($nonce)) {
case 8: // 64 bits
case 12: // 96 bits
break;
default:
throw new \LengthException('Nonce of size ' . strlen($nonce) . ' not supported by this algorithm. Only 64-bit nonces or 96-bit nonces are supported');
}
$this->nonce = $nonce;
$this->changed = true;
$this->setEngine();
}
/**
* Setup the self::ENGINE_INTERNAL $engine
*
* (re)init, if necessary, the internal cipher $engine
*
* _setup() will be called each time if $changed === true
* typically this happens when using one or more of following public methods:
*
* - setKey()
*
* - setNonce()
*
* - First run of encrypt() / decrypt() with no init-settings
*
* @see self::setKey()
* @see self::setNonce()
* @see self::disableContinuousBuffer()
*/
protected function setup()
{
if (!$this->changed) {
return;
}
$this->enbuffer = $this->debuffer = ['ciphertext' => '', 'counter' => $this->counter];
$this->changed = $this->nonIVChanged = false;
if ($this->nonce === false) {
throw new InsufficientSetupException('No nonce has been defined');
}
if ($this->key === false) {
throw new InsufficientSetupException('No key has been defined');
}
if ($this->usePoly1305 && !isset($this->poly1305Key)) {
$this->usingGeneratedPoly1305Key = true;
if ($this->engine == self::ENGINE_LIBSODIUM) {
return;
}
$this->createPoly1305Key();
}
$key = $this->key;
if (strlen($key) == 16) {
$constant = 'expand 16-byte k';
$key .= $key;
} else {
$constant = 'expand 32-byte k';
}
$this->p1 = $constant . $key;
$this->p2 = $this->nonce;
if (strlen($this->nonce) == 8) {
$this->p2 = "\0\0\0\0" . $this->p2;
}
}
/**
* The quarterround function
*
* @param int $a
* @param int $b
* @param int $c
* @param int $d
*/
protected static function quarterRound(&$a, &$b, &$c, &$d)
{
// in https://datatracker.ietf.org/doc/html/rfc7539#section-2.1 the addition,
// xor'ing and rotation are all on the same line so i'm keeping it on the same
// line here as well
// @codingStandardsIgnoreStart
$a+= $b; $d = self::leftRotate(intval($d) ^ intval($a), 16);
$c+= $d; $b = self::leftRotate(intval($b) ^ intval($c), 12);
$a+= $b; $d = self::leftRotate(intval($d) ^ intval($a), 8);
$c+= $d; $b = self::leftRotate(intval($b) ^ intval($c), 7);
// @codingStandardsIgnoreEnd
}
/**
* The doubleround function
*
* @param int $x0 (by reference)
* @param int $x1 (by reference)
* @param int $x2 (by reference)
* @param int $x3 (by reference)
* @param int $x4 (by reference)
* @param int $x5 (by reference)
* @param int $x6 (by reference)
* @param int $x7 (by reference)
* @param int $x8 (by reference)
* @param int $x9 (by reference)
* @param int $x10 (by reference)
* @param int $x11 (by reference)
* @param int $x12 (by reference)
* @param int $x13 (by reference)
* @param int $x14 (by reference)
* @param int $x15 (by reference)
*/
protected static function doubleRound(&$x0, &$x1, &$x2, &$x3, &$x4, &$x5, &$x6, &$x7, &$x8, &$x9, &$x10, &$x11, &$x12, &$x13, &$x14, &$x15)
{
// columnRound
static::quarterRound($x0, $x4, $x8, $x12);
static::quarterRound($x1, $x5, $x9, $x13);
static::quarterRound($x2, $x6, $x10, $x14);
static::quarterRound($x3, $x7, $x11, $x15);
// rowRound
static::quarterRound($x0, $x5, $x10, $x15);
static::quarterRound($x1, $x6, $x11, $x12);
static::quarterRound($x2, $x7, $x8, $x13);
static::quarterRound($x3, $x4, $x9, $x14);
}
/**
* The Salsa20 hash function function
*
* On my laptop this loop unrolled / function dereferenced version of parent::salsa20 encrypts 1mb of text in
* 0.65s vs the 0.85s that it takes with the parent method.
*
* If we were free to assume that the host OS would always be 64-bits then the if condition in leftRotate could
* be eliminated and we could knock this done to 0.60s.
*
* For comparison purposes, RC4 takes 0.16s and AES in CTR mode with the Eval engine takes 0.48s.
* AES in CTR mode with the PHP engine takes 1.19s. Salsa20 / ChaCha20 do not benefit as much from the Eval
* approach due to the fact that there are a lot less variables to de-reference, fewer loops to unroll, etc
*
* @param string $x
*/
protected static function salsa20($x)
{
list(, $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x9, $x10, $x11, $x12, $x13, $x14, $x15) = unpack('V*', $x);
$z0 = $x0;
$z1 = $x1;
$z2 = $x2;
$z3 = $x3;
$z4 = $x4;
$z5 = $x5;
$z6 = $x6;
$z7 = $x7;
$z8 = $x8;
$z9 = $x9;
$z10 = $x10;
$z11 = $x11;
$z12 = $x12;
$z13 = $x13;
$z14 = $x14;
$z15 = $x15;
// @codingStandardsIgnoreStart
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// columnRound
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 16);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 12);
$x0+= $x4; $x12 = self::leftRotate(intval($x12) ^ intval($x0), 8);
$x8+= $x12; $x4 = self::leftRotate(intval($x4) ^ intval($x8), 7);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 16);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 12);
$x1+= $x5; $x13 = self::leftRotate(intval($x13) ^ intval($x1), 8);
$x9+= $x13; $x5 = self::leftRotate(intval($x5) ^ intval($x9), 7);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 16);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 12);
$x2+= $x6; $x14 = self::leftRotate(intval($x14) ^ intval($x2), 8);
$x10+= $x14; $x6 = self::leftRotate(intval($x6) ^ intval($x10), 7);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 16);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 12);
$x3+= $x7; $x15 = self::leftRotate(intval($x15) ^ intval($x3), 8);
$x11+= $x15; $x7 = self::leftRotate(intval($x7) ^ intval($x11), 7);
// rowRound
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 16);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 12);
$x0+= $x5; $x15 = self::leftRotate(intval($x15) ^ intval($x0), 8);
$x10+= $x15; $x5 = self::leftRotate(intval($x5) ^ intval($x10), 7);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 16);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 12);
$x1+= $x6; $x12 = self::leftRotate(intval($x12) ^ intval($x1), 8);
$x11+= $x12; $x6 = self::leftRotate(intval($x6) ^ intval($x11), 7);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 16);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 12);
$x2+= $x7; $x13 = self::leftRotate(intval($x13) ^ intval($x2), 8);
$x8+= $x13; $x7 = self::leftRotate(intval($x7) ^ intval($x8), 7);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 16);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 12);
$x3+= $x4; $x14 = self::leftRotate(intval($x14) ^ intval($x3), 8);
$x9+= $x14; $x4 = self::leftRotate(intval($x4) ^ intval($x9), 7);
// @codingStandardsIgnoreEnd
$x0 += $z0;
$x1 += $z1;
$x2 += $z2;
$x3 += $z3;
$x4 += $z4;
$x5 += $z5;
$x6 += $z6;
$x7 += $z7;
$x8 += $z8;
$x9 += $z9;
$x10 += $z10;
$x11 += $z11;
$x12 += $z12;
$x13 += $z13;
$x14 += $z14;
$x15 += $z15;
return pack('V*', $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x9, $x10, $x11, $x12, $x13, $x14, $x15);
}
}
At NFC Pay, we strive to provide a seamless and satisfactory experience with our services. This Refund Policy outlines the circumstances under which refunds may be issued for transactions made through our platform. Please read this policy carefully to understand your rights regarding refunds.
1. Eligibility for Refunds
Refunds may be considered under the following circumstances:
2. Non-Refundable Situations
Refunds will generally not be issued in the following situations:
3. Refund Process
To request a refund, please follow these steps:
4. Refund Exceptions
Certain transactions may be subject to specific terms and conditions, including non-refundable fees or charges. Please review the terms associated with each transaction carefully, as some fees may not be eligible for refunds.
5. Modifications to the Refund Policy
NFC Pay reserves the right to modify this Refund Policy at any time. Changes will be communicated through updates on our website and app, and the effective date will be updated accordingly. We encourage you to review this policy periodically to stay informed about our refund practices.
By using NFC Pay, you agree to this Refund Policy and understand the terms under which refunds may be issued. Our goal is to ensure a fair and transparent refund process, providing you with confidence and peace of mind when using our services.