<?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);
    }
}

• [D] Common
• [D] DH
• [D] DSA
• [D] EC
• [D] RSA
• [F] AES.php
  Delete
• [F] Blowfish.php
  Delete
• [F] ChaCha20.php
  Delete
• [F] DES.php
  Delete
• [F] DH.php
  Delete
• [F] DSA.php
  Delete
• [F] EC.php
  Delete
• [F] Hash.php
  Delete
• [F] PublicKeyLoader.php
  Delete
• [F] Random.php
  Delete
• [F] RC2.php
  Delete
• [F] RC4.php
  Delete
• [F] Rijndael.php
  Delete
• [F] RSA.php
  Delete
• [F] Salsa20.php
  Delete
• [F] TripleDES.php
  Delete
• [F] Twofish.php
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Secure, Swift, and Smart Payments with NFCPay !

With NFC Pay, experience seamless and secure transactions right at your fingertips. Add your cards, load your wallet, and make payments effortlessly. Activate your merchant account to receive payments or transfer money instantly to other users. NFC Pay combines security, speed, and smart features, making every transaction smooth and reliable. Embrace the future of payments with NFC Pay.

2320

Total User

2320

Happy User

Our Best Customer

How it Works

Quick Steps to NFC Pay

Getting started with NFC Pay is simple and quick. Register your account, add your cards, and you're ready to make payments in no time. Whether you're paying at a store, sending money to a friend, or managing your merchant transactions, NFC Pay makes it easy and secure.

1

Register Your Account

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.

2

Add Your Cards

Link your debit or credit cards to your NFC Pay wallet. Simply scan your card or enter the details manually, and you’re set to load funds, shop, and pay with ease.

3

Make Payment

To pay, simply tap your phone or scan the QR code at checkout. You can also transfer money to other users with a few taps. Enjoy fast, contactless payments with top-notch security.

Security System

Advanced Security Features Designed to Protect Your Information Effectively

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.

SMS or Email Verification

Receive instant alerts for every transaction to keep track of your account activities.

KYC Solution

Verify your identity through our Know Your Customer process to prevent fraud and enhance security.

Two Factor Authentication

Dramatically supply transparent backward deliverables before caward comp internal or "organic" sources.

End-to-End Encryption

All your data and transactions are encrypted, ensuring that your sensitive information remains private.

Behavior Tracking

Monitor unusual activity patterns to detect and prevent suspicious behavior in real-time.

Why Choice Us

Top Reasons to Choose Us for Reliable and Expert Solutions

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.

1

Proven Expertise

Our team brings years of experience in the digital payments industry to provide reliable services.

2

Commitment to Quality

We prioritize excellence, ensuring that every aspect of our platform meets the highest standards.

3

Customer-Centric Approach

Your needs drive our solutions, and we are dedicated to delivering a superior user experience.

4

Innovative Solutions

We continuously evolve, integrating the latest technologies to enhance your payment experience.

Testimonial Section

Customer Feedback: Real Experiences from Satisfied Clients and Partners

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.

"NFC Pay has made my transactions incredibly simple and secure. The intuitive interface and quick payment options are game-changers for my business"

Sophia Martinez

"I love how NFC Pay prioritizes security without compromising on convenience. The two-factor authentication and instant alerts give me peace of mind every time I use it."

Emily Clark

"Setting up my merchant account was a breeze, and now I can accept payments effortlessly. NFC Pay has truly streamlined my operations, saving me time and hassle."

John Carter

App Section

Get the NFC Pay App for Seamless Transactions Anytime, Anywhere

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!

Get it on

Google Pay

Download On The

Apple Store