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<?php
/**
* Pure-PHP implementation of RC4.
*
* Uses mcrypt, if available, and an internal implementation, otherwise.
*
* PHP version 5
*
* Useful resources are as follows:
*
* - {@link http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt ARCFOUR Algorithm}
* - {@link http://en.wikipedia.org/wiki/RC4 - Wikipedia: RC4}
*
* RC4 is also known as ARCFOUR or ARC4. The reason is elaborated upon at Wikipedia. This class is named RC4 and not
* ARCFOUR or ARC4 because RC4 is how it is referred to in the SSH1 specification.
*
* Here's a short example of how to use this library:
* <code>
* <?php
* include 'vendor/autoload.php';
*
* $rc4 = new \phpseclib3\Crypt\RC4();
*
* $rc4->setKey('abcdefgh');
*
* $size = 10 * 1024;
* $plaintext = '';
* for ($i = 0; $i < $size; $i++) {
* $plaintext.= 'a';
* }
*
* echo $rc4->decrypt($rc4->encrypt($plaintext));
* ?>
* </code>
*
* @author Jim Wigginton <terrafrost@php.net>
* @copyright 2007 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib3\Crypt;
use phpseclib3\Crypt\Common\StreamCipher;
/**
* Pure-PHP implementation of RC4.
*
* @author Jim Wigginton <terrafrost@php.net>
*/
class RC4 extends StreamCipher
{
/**
* @see \phpseclib3\Crypt\RC4::_crypt()
*/
const ENCRYPT = 0;
/**
* @see \phpseclib3\Crypt\RC4::_crypt()
*/
const DECRYPT = 1;
/**
* Key Length (in bytes)
*
* @see \phpseclib3\Crypt\RC4::setKeyLength()
* @var int
*/
protected $key_length = 128; // = 1024 bits
/**
* The mcrypt specific name of the cipher
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::cipher_name_mcrypt
* @var string
*/
protected $cipher_name_mcrypt = 'arcfour';
/**
* The Key
*
* @see self::setKey()
* @var string
*/
protected $key;
/**
* The Key Stream for decryption and encryption
*
* @see self::setKey()
* @var array
*/
private $stream;
/**
* 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)
{
if ($engine == self::ENGINE_OPENSSL) {
if ($this->continuousBuffer) {
return false;
}
// quoting https://www.openssl.org/news/openssl-3.0-notes.html, OpenSSL 3.0.1
// "Moved all variations of the EVP ciphers CAST5, BF, IDEA, SEED, RC2, RC4, RC5, and DES to the legacy provider"
// in theory openssl_get_cipher_methods() should catch this but, on GitHub Actions, at least, it does not
if (defined('OPENSSL_VERSION_TEXT') && version_compare(preg_replace('#OpenSSL (\d+\.\d+\.\d+) .*#', '$1', OPENSSL_VERSION_TEXT), '3.0.1', '>=')) {
return false;
}
$this->cipher_name_openssl = 'rc4-40';
}
return parent::isValidEngineHelper($engine);
}
/**
* Sets the key length
*
* Keys can be between 1 and 256 bytes long.
*
* @param int $length
* @throws \LengthException if the key length is invalid
*/
public function setKeyLength($length)
{
if ($length < 8 || $length > 2048) {
throw new \LengthException('Key size of ' . $length . ' bits is not supported by this algorithm. Only keys between 1 and 256 bytes are supported');
}
$this->key_length = $length >> 3;
parent::setKeyLength($length);
}
/**
* Sets the key length
*
* Keys can be between 1 and 256 bytes long.
*
* @param string $key
*/
public function setKey($key)
{
$length = strlen($key);
if ($length < 1 || $length > 256) {
throw new \LengthException('Key size of ' . $length . ' bytes is not supported by RC4. Keys must be between 1 and 256 bytes long');
}
parent::setKey($key);
}
/**
* Encrypts a message.
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt()
* @see self::crypt()
* @param string $plaintext
* @return string $ciphertext
*/
public function encrypt($plaintext)
{
if ($this->engine != self::ENGINE_INTERNAL) {
return parent::encrypt($plaintext);
}
return $this->crypt($plaintext, self::ENCRYPT);
}
/**
* 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 ($this->engine != self::ENGINE_INTERNAL) {
return parent::decrypt($ciphertext);
}
return $this->crypt($ciphertext, self::DECRYPT);
}
/**
* Encrypts a block
*
* @param string $in
*/
protected function encryptBlock($in)
{
// RC4 does not utilize this method
}
/**
* Decrypts a block
*
* @param string $in
*/
protected function decryptBlock($in)
{
// RC4 does not utilize this method
}
/**
* Setup the key (expansion)
*
* @see \phpseclib3\Crypt\Common\SymmetricKey::_setupKey()
*/
protected function setupKey()
{
$key = $this->key;
$keyLength = strlen($key);
$keyStream = range(0, 255);
$j = 0;
for ($i = 0; $i < 256; $i++) {
$j = ($j + $keyStream[$i] + ord($key[$i % $keyLength])) & 255;
$temp = $keyStream[$i];
$keyStream[$i] = $keyStream[$j];
$keyStream[$j] = $temp;
}
$this->stream = [];
$this->stream[self::DECRYPT] = $this->stream[self::ENCRYPT] = [
0, // index $i
0, // index $j
$keyStream
];
}
/**
* Encrypts or decrypts a message.
*
* @see self::encrypt()
* @see self::decrypt()
* @param string $text
* @param int $mode
* @return string $text
*/
private function crypt($text, $mode)
{
if ($this->changed) {
$this->setup();
}
$stream = &$this->stream[$mode];
if ($this->continuousBuffer) {
$i = &$stream[0];
$j = &$stream[1];
$keyStream = &$stream[2];
} else {
$i = $stream[0];
$j = $stream[1];
$keyStream = $stream[2];
}
$len = strlen($text);
for ($k = 0; $k < $len; ++$k) {
$i = ($i + 1) & 255;
$ksi = $keyStream[$i];
$j = ($j + $ksi) & 255;
$ksj = $keyStream[$j];
$keyStream[$i] = $ksj;
$keyStream[$j] = $ksi;
$text[$k] = $text[$k] ^ chr($keyStream[($ksj + $ksi) & 255]);
}
return $text;
}
}
How it Works
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Download the NFC Pay app and sign up with your email or phone number. Complete the registration process by verifying your identity, and set up your secure PIN to protect your account.
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Security System
NFC Pay prioritizes your security with advanced features that safeguard every transaction. From SMS or email verification to end-to-end encryption, we've implemented robust measures to ensure your data is always protected. Our security systems are designed to prevent unauthorized access and provide you with a safe and reliable payment experience.
Receive instant alerts for every transaction to keep track of your account activities.
Verify your identity through our Know Your Customer process to prevent fraud and enhance security.
Dramatically supply transparent backward deliverables before caward comp internal or "organic" sources.
All your data and transactions are encrypted, ensuring that your sensitive information remains private.
Monitor unusual activity patterns to detect and prevent suspicious behavior in real-time.
Why Choice Us
With NFC Pay, you get a trusted platform backed by proven expertise and a commitment to quality. We put our customers first, offering innovative solutions tailored to your needs, ensuring every transaction is secure, swift, and seamless.
Our team brings years of experience in the digital payments industry to provide reliable services.
We prioritize excellence, ensuring that every aspect of our platform meets the highest standards.
Your needs drive our solutions, and we are dedicated to delivering a superior user experience.
We continuously evolve, integrating the latest technologies to enhance your payment experience.
Testimonial Section
Hear from our users who trust NFC Pay for their everyday transactions. Our commitment to security, ease of use, and exceptional service shines through in their experiences. See why our clients choose NFC Pay for their payment needs and how it has transformed the way they manage their finances.
App Section
Unlock the full potential of NFC Pay by downloading our app, designed to bring secure, swift, and smart transactions to your fingertips. Whether you're paying at a store, transferring money to friends, or managing your business payments, the NFC Pay app makes it effortless. Available on both iOS and Android, it's your all-in-one solution for convenient and reliable digital payments. Download now and experience the future of payments!