/home/kueuepay/public_html/vendor/phpseclib/phpseclib/phpseclib/Crypt/Salsa20.php
<?php
/**
* Pure-PHP implementation of Salsa20.
*
* 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\Common\Functions\Strings;
use phpseclib3\Crypt\Common\StreamCipher;
use phpseclib3\Exception\BadDecryptionException;
use phpseclib3\Exception\InsufficientSetupException;
/**
* Pure-PHP implementation of Salsa20.
*
* @author Jim Wigginton <terrafrost@php.net>
*/
class Salsa20 extends StreamCipher
{
/**
* Part 1 of the state
*
* @var string|false
*/
protected $p1 = false;
/**
* Part 2 of the state
*
* @var string|false
*/
protected $p2 = false;
/**
* Key Length (in bytes)
*
* @var int
*/
protected $key_length = 32; // = 256 bits
/**
* @see \phpseclib3\Crypt\Salsa20::crypt()
*/
const ENCRYPT = 0;
/**
* @see \phpseclib3\Crypt\Salsa20::crypt()
*/
const DECRYPT = 1;
/**
* Encryption buffer for continuous mode
*
* @var array
*/
protected $enbuffer;
/**
* Decryption buffer for continuous mode
*
* @var array
*/
protected $debuffer;
/**
* Counter
*
* @var int
*/
protected $counter = 0;
/**
* Using Generated Poly1305 Key
*
* @var boolean
*/
protected $usingGeneratedPoly1305Key = false;
/**
* Salsa20 uses a nonce
*
* @return bool
*/
public function usesNonce()
{
return true;
}
/**
* Sets the key.
*
* @param string $key
* @throws \LengthException if the key length isn't supported
*/
public function setKey($key)
{
switch (strlen($key)) {
case 16:
case 32:
break;
default:
throw new \LengthException('Key of size ' . strlen($key) . ' not supported by this algorithm. Only keys of sizes 16 or 32 are supported');
}
parent::setKey($key);
}
/**
* Sets the nonce.
*
* @param string $nonce
*/
public function setNonce($nonce)
{
if (strlen($nonce) != 8) {
throw new \LengthException('Nonce of size ' . strlen($key) . ' not supported by this algorithm. Only an 64-bit nonce is supported');
}
$this->nonce = $nonce;
$this->changed = true;
$this->setEngine();
}
/**
* Sets the counter.
*
* @param int $counter
*/
public function setCounter($counter)
{
$this->counter = $counter;
$this->setEngine();
}
/**
* Creates a Poly1305 key using the method discussed in RFC8439
*
* See https://tools.ietf.org/html/rfc8439#section-2.6.1
*/
protected function createPoly1305Key()
{
if ($this->nonce === false) {
throw new InsufficientSetupException('No nonce has been defined');
}
if ($this->key === false) {
throw new InsufficientSetupException('No key has been defined');
}
$c = clone $this;
$c->setCounter(0);
$c->usePoly1305 = false;
$block = $c->encrypt(str_repeat("\0", 256));
$this->setPoly1305Key(substr($block, 0, 32));
if ($this->counter == 0) {
$this->counter++;
}
}
/**
* 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;
$this->createPoly1305Key();
}
$key = $this->key;
if (strlen($key) == 16) {
$constant = 'expand 16-byte k';
$key .= $key;
} else {
$constant = 'expand 32-byte k';
}
$this->p1 = substr($constant, 0, 4) .
substr($key, 0, 16) .
substr($constant, 4, 4) .
$this->nonce .
"\0\0\0\0";
$this->p2 = substr($constant, 8, 4) .
substr($key, 16, 16) .
substr($constant, 12, 4);
}
/**
* Setup the key (expansion)
*/
protected function setupKey()
{
// Salsa20 does not utilize this method
}
/**
* Encrypts a message.
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt()
* @see self::crypt()
* @param string $plaintext
* @return string $ciphertext
*/
public function encrypt($plaintext)
{
$ciphertext = $this->crypt($plaintext, self::ENCRYPT);
if (isset($this->poly1305Key)) {
$this->newtag = $this->poly1305($ciphertext);
}
return $ciphertext;
}
/**
* 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)
{
if (isset($this->poly1305Key)) {
if ($this->oldtag === false) {
throw new InsufficientSetupException('Authentication Tag has not been set');
}
$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;
}
return $this->crypt($ciphertext, self::DECRYPT);
}
/**
* Encrypts a block
*
* @param string $in
*/
protected function encryptBlock($in)
{
// Salsa20 does not utilize this method
}
/**
* Decrypts a block
*
* @param string $in
*/
protected function decryptBlock($in)
{
// Salsa20 does not utilize this method
}
/**
* Encrypts or decrypts a message.
*
* @see self::encrypt()
* @see self::decrypt()
* @param string $text
* @param int $mode
* @return string $text
*/
private function crypt($text, $mode)
{
$this->setup();
if (!$this->continuousBuffer) {
if ($this->engine == self::ENGINE_OPENSSL) {
$iv = pack('V', $this->counter) . $this->p2;
return openssl_encrypt(
$text,
$this->cipher_name_openssl,
$this->key,
OPENSSL_RAW_DATA,
$iv
);
}
$i = $this->counter;
$blocks = str_split($text, 64);
foreach ($blocks as &$block) {
$block ^= static::salsa20($this->p1 . pack('V', $i++) . $this->p2);
}
return implode('', $blocks);
}
if ($mode == self::ENCRYPT) {
$buffer = &$this->enbuffer;
} else {
$buffer = &$this->debuffer;
}
if (!strlen($buffer['ciphertext'])) {
$ciphertext = '';
} else {
$ciphertext = $text ^ Strings::shift($buffer['ciphertext'], strlen($text));
$text = substr($text, strlen($ciphertext));
if (!strlen($text)) {
return $ciphertext;
}
}
$overflow = strlen($text) % 64; // & 0x3F
if ($overflow) {
$text2 = Strings::pop($text, $overflow);
if ($this->engine == self::ENGINE_OPENSSL) {
$iv = pack('V', $buffer['counter']) . $this->p2;
// at this point $text should be a multiple of 64
$buffer['counter'] += (strlen($text) >> 6) + 1; // ie. divide by 64
$encrypted = openssl_encrypt(
$text . str_repeat("\0", 64),
$this->cipher_name_openssl,
$this->key,
OPENSSL_RAW_DATA,
$iv
);
$temp = Strings::pop($encrypted, 64);
} else {
$blocks = str_split($text, 64);
if (strlen($text)) {
foreach ($blocks as &$block) {
$block ^= static::salsa20($this->p1 . pack('V', $buffer['counter']++) . $this->p2);
}
}
$encrypted = implode('', $blocks);
$temp = static::salsa20($this->p1 . pack('V', $buffer['counter']++) . $this->p2);
}
$ciphertext .= $encrypted . ($text2 ^ $temp);
$buffer['ciphertext'] = substr($temp, $overflow);
} elseif (!strlen($buffer['ciphertext'])) {
if ($this->engine == self::ENGINE_OPENSSL) {
$iv = pack('V', $buffer['counter']) . $this->p2;
$buffer['counter'] += (strlen($text) >> 6);
$ciphertext .= openssl_encrypt(
$text,
$this->cipher_name_openssl,
$this->key,
OPENSSL_RAW_DATA,
$iv
);
} else {
$blocks = str_split($text, 64);
foreach ($blocks as &$block) {
$block ^= static::salsa20($this->p1 . pack('V', $buffer['counter']++) . $this->p2);
}
$ciphertext .= implode('', $blocks);
}
}
return $ciphertext;
}
/**
* Left Rotate
*
* @param int $x
* @param int $n
* @return int
*/
protected static function leftRotate($x, $n)
{
if (PHP_INT_SIZE == 8) {
$r1 = $x << $n;
$r1 &= 0xFFFFFFFF;
$r2 = ($x & 0xFFFFFFFF) >> (32 - $n);
} else {
$x = (int) $x;
$r1 = $x << $n;
$r2 = $x >> (32 - $n);
$r2 &= (1 << $n) - 1;
}
return $r1 | $r2;
}
/**
* The quarterround function
*
* @param int $a
* @param int $b
* @param int $c
* @param int $d
*/
protected static function quarterRound(&$a, &$b, &$c, &$d)
{
$b ^= self::leftRotate($a + $d, 7);
$c ^= self::leftRotate($b + $a, 9);
$d ^= self::leftRotate($c + $b, 13);
$a ^= self::leftRotate($d + $c, 18);
}
/**
* 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, $x12);
static::quarterRound($x5, $x9, $x13, $x1);
static::quarterRound($x10, $x14, $x2, $x6);
static::quarterRound($x15, $x3, $x7, $x11);
// rowRound
static::quarterRound($x0, $x1, $x2, $x3);
static::quarterRound($x5, $x6, $x7, $x4);
static::quarterRound($x10, $x11, $x8, $x9);
static::quarterRound($x15, $x12, $x13, $x14);
}
/**
* The Salsa20 hash function function
*
* @param string $x
*/
protected static function salsa20($x)
{
$z = $x = unpack('V*', $x);
for ($i = 0; $i < 10; $i++) {
static::doubleRound($z[1], $z[2], $z[3], $z[4], $z[5], $z[6], $z[7], $z[8], $z[9], $z[10], $z[11], $z[12], $z[13], $z[14], $z[15], $z[16]);
}
for ($i = 1; $i <= 16; $i++) {
$x[$i] += $z[$i];
}
return pack('V*', ...$x);
}
/**
* Calculates Poly1305 MAC
*
* @see self::decrypt()
* @see self::encrypt()
* @param string $ciphertext
* @return string
*/
protected function poly1305($ciphertext)
{
if (!$this->usingGeneratedPoly1305Key) {
return parent::poly1305($this->aad . $ciphertext);
} else {
/*
sodium_crypto_aead_chacha20poly1305_encrypt does not calculate the poly1305 tag
the same way sodium_crypto_aead_chacha20poly1305_ietf_encrypt does. you can see
how the latter encrypts it in Salsa20::encrypt(). here's how the former encrypts
it:
$this->newtag = $this->poly1305(
$this->aad .
pack('V', strlen($this->aad)) . "\0\0\0\0" .
$ciphertext .
pack('V', strlen($ciphertext)) . "\0\0\0\0"
);
phpseclib opts to use the IETF construction, even when the nonce is 64-bits
instead of 96-bits
*/
return parent::poly1305(
self::nullPad128($this->aad) .
self::nullPad128($ciphertext) .
pack('V', strlen($this->aad)) . "\0\0\0\0" .
pack('V', strlen($ciphertext)) . "\0\0\0\0"
);
}
}
}
About
top
About NFC Pay: Our Story and Mission
NFC Pay was founded with a vision to transform the way people handle transactions. Our journey is defined by a commitment to innovation, security, and convenience. We strive to deliver seamless, user-friendly payment solutions that make everyday transactions effortless and secure. Our mission is to empower you to pay with ease and confidence, anytime, anywhere.
Simplifying Payments, One Tap at a Time.
Reinventing Your Wallet for Modern Convenience.
Smart Payments for a Effortless Lifestyle.
Experience the Ease of Tap and Pay.
Innovative Solutions for Your Daily Transactions.
Frequently Asked Questions About NFC Pay
Here are answers to some common questions about NFC Pay. We aim to provide clear and concise information to help you understand how our platform works and how it can benefit you. If you have any further inquiries, please don’t hesitate to contact our support team.
How do I register for NFC Pay?
Download the app and sign up using your email or phone number, then complete the verification process.
Is my payment information secure?
Yes, we use advanced encryption and security protocols to protect your payment details.
Can I add multiple cards to my NFC Pay wallet?
Absolutely, you can link multiple debit or credit cards to your wallet.
How do I transfer money to another user?
Go to the transfer section, select the recipient, enter the amount, and authorize the transfer.
What should I do if I forget my PIN?
Use the “Forgot PIN” feature in the app to reset it following the provided instructions.
How can I activate my merchant account?
Sign up for a merchant account through the app and follow the setup instructions to start accepting payments.
Can I track my payment status?
Yes, you can view and track your payment status in the account dashboard
In the digital age, privacy concerns have become increasingly paramount, prompting the European Union to enact the General Data Protection Regulation (GDPR) in 2018. Among its many provisions, GDPR sets strict guidelines for the collection and processing of personal data, including the use of cookies on websites. Privacy Policy
Allow
Decline
