<?php

if (class_exists('ParagonIE_Sodium_Core_SipHash', false)) {
    return;
}

/**
 * Class ParagonIE_SodiumCompat_Core_SipHash
 *
 * Only uses 32-bit arithmetic, while the original SipHash used 64-bit integers
 */
class ParagonIE_Sodium_Core_SipHash extends ParagonIE_Sodium_Core_Util
{
    /**
     * @internal You should not use this directly from another application
     *
     * @param int[] $v
     * @return int[]
     *
     */
    public static function sipRound(array $v)
    {
        # v0 += v1;
        list($v[0], $v[1]) = self::add(
            array($v[0], $v[1]),
            array($v[2], $v[3])
        );

        #  v1=ROTL(v1,13);
        list($v[2], $v[3]) = self::rotl_64((int) $v[2], (int) $v[3], 13);

        #  v1 ^= v0;
        $v[2] = (int) $v[2] ^ (int) $v[0];
        $v[3] = (int) $v[3] ^ (int) $v[1];

        #  v0=ROTL(v0,32);
        list($v[0], $v[1]) = self::rotl_64((int) $v[0], (int) $v[1], 32);

        # v2 += v3;
        list($v[4], $v[5]) = self::add(
            array((int) $v[4], (int) $v[5]),
            array((int) $v[6], (int) $v[7])
        );

        # v3=ROTL(v3,16);
        list($v[6], $v[7]) = self::rotl_64((int) $v[6], (int) $v[7], 16);

        #  v3 ^= v2;
        $v[6] = (int) $v[6] ^ (int) $v[4];
        $v[7] = (int) $v[7] ^ (int) $v[5];

        # v0 += v3;
        list($v[0], $v[1]) = self::add(
            array((int) $v[0], (int) $v[1]),
            array((int) $v[6], (int) $v[7])
        );

        # v3=ROTL(v3,21);
        list($v[6], $v[7]) = self::rotl_64((int) $v[6], (int) $v[7], 21);

        # v3 ^= v0;
        $v[6] = (int) $v[6] ^ (int) $v[0];
        $v[7] = (int) $v[7] ^ (int) $v[1];

        # v2 += v1;
        list($v[4], $v[5]) = self::add(
            array((int) $v[4], (int) $v[5]),
            array((int) $v[2], (int) $v[3])
        );

        # v1=ROTL(v1,17);
        list($v[2], $v[3]) = self::rotl_64((int) $v[2], (int) $v[3], 17);

        #  v1 ^= v2;;
        $v[2] = (int) $v[2] ^ (int) $v[4];
        $v[3] = (int) $v[3] ^ (int) $v[5];

        # v2=ROTL(v2,32)
        list($v[4], $v[5]) = self::rotl_64((int) $v[4], (int) $v[5], 32);

        return $v;
    }

    /**
     * Add two 32 bit integers representing a 64-bit integer.
     *
     * @internal You should not use this directly from another application
     *
     * @param int[] $a
     * @param int[] $b
     * @return array<int, mixed>
     */
    public static function add(array $a, array $b)
    {
        /** @var int $x1 */
        $x1 = $a[1] + $b[1];
        /** @var int $c */
        $c = $x1 >> 32; // Carry if ($a + $b) > 0xffffffff
        /** @var int $x0 */
        $x0 = $a[0] + $b[0] + $c;
        return array(
            $x0 & 0xffffffff,
            $x1 & 0xffffffff
        );
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param int $int0
     * @param int $int1
     * @param int $c
     * @return array<int, mixed>
     */
    public static function rotl_64($int0, $int1, $c)
    {
        $int0 &= 0xffffffff;
        $int1 &= 0xffffffff;
        $c &= 63;
        if ($c === 32) {
            return array($int1, $int0);
        }
        if ($c > 31) {
            $tmp = $int1;
            $int1 = $int0;
            $int0 = $tmp;
            $c &= 31;
        }
        if ($c === 0) {
            return array($int0, $int1);
        }
        return array(
            0xffffffff & (
                ($int0 << $c)
                    |
                ($int1 >> (32 - $c))
            ),
            0xffffffff & (
                ($int1 << $c)
                    |
                ($int0 >> (32 - $c))
            ),
        );
    }

    /**
     * Implements Siphash-2-4 using only 32-bit numbers.
     *
     * When we split an int into two, the higher bits go to the lower index.
     * e.g. 0xDEADBEEFAB10C92D becomes [
     *     0 => 0xDEADBEEF,
     *     1 => 0xAB10C92D
     * ].
     *
     * @internal You should not use this directly from another application
     *
     * @param string $in
     * @param string $key
     * @return string
     * @throws SodiumException
     * @throws TypeError
     */
    public static function sipHash24($in, $key)
    {
        $inlen = self::strlen($in);

        # /* "somepseudorandomlygeneratedbytes" */
        # u64 v0 = 0x736f6d6570736575ULL;
        # u64 v1 = 0x646f72616e646f6dULL;
        # u64 v2 = 0x6c7967656e657261ULL;
        # u64 v3 = 0x7465646279746573ULL;
        $v = array(
            0x736f6d65, // 0
            0x70736575, // 1
            0x646f7261, // 2
            0x6e646f6d, // 3
            0x6c796765, // 4
            0x6e657261, // 5
            0x74656462, // 6
            0x79746573  // 7
        );
        // v0 => $v[0], $v[1]
        // v1 => $v[2], $v[3]
        // v2 => $v[4], $v[5]
        // v3 => $v[6], $v[7]

        # u64 k0 = LOAD64_LE( k );
        # u64 k1 = LOAD64_LE( k + 8 );
        $k = array(
            self::load_4(self::substr($key, 4, 4)),
            self::load_4(self::substr($key, 0, 4)),
            self::load_4(self::substr($key, 12, 4)),
            self::load_4(self::substr($key, 8, 4))
        );
        // k0 => $k[0], $k[1]
        // k1 => $k[2], $k[3]

        # b = ( ( u64 )inlen ) << 56;
        $b = array(
            $inlen << 24,
            0
        );
        // See docblock for why the 0th index gets the higher bits.

        # v3 ^= k1;
        $v[6] ^= $k[2];
        $v[7] ^= $k[3];
        # v2 ^= k0;
        $v[4] ^= $k[0];
        $v[5] ^= $k[1];
        # v1 ^= k1;
        $v[2] ^= $k[2];
        $v[3] ^= $k[3];
        # v0 ^= k0;
        $v[0] ^= $k[0];
        $v[1] ^= $k[1];

        $left = $inlen;
        # for ( ; in != end; in += 8 )
        while ($left >= 8) {
            # m = LOAD64_LE( in );
            $m = array(
                self::load_4(self::substr($in, 4, 4)),
                self::load_4(self::substr($in, 0, 4))
            );

            # v3 ^= m;
            $v[6] ^= $m[0];
            $v[7] ^= $m[1];

            # SIPROUND;
            # SIPROUND;
            $v = self::sipRound($v);
            $v = self::sipRound($v);

            # v0 ^= m;
            $v[0] ^= $m[0];
            $v[1] ^= $m[1];

            $in = self::substr($in, 8);
            $left -= 8;
        }

        # switch( left )
        #  {
        #     case 7: b |= ( ( u64 )in[ 6] )  << 48;
        #     case 6: b |= ( ( u64 )in[ 5] )  << 40;
        #     case 5: b |= ( ( u64 )in[ 4] )  << 32;
        #     case 4: b |= ( ( u64 )in[ 3] )  << 24;
        #     case 3: b |= ( ( u64 )in[ 2] )  << 16;
        #     case 2: b |= ( ( u64 )in[ 1] )  <<  8;
        #     case 1: b |= ( ( u64 )in[ 0] ); break;
        #     case 0: break;
        # }
        switch ($left) {
            case 7:
                $b[0] |= self::chrToInt($in[6]) << 16;
            case 6:
                $b[0] |= self::chrToInt($in[5]) << 8;
            case 5:
                $b[0] |= self::chrToInt($in[4]);
            case 4:
                $b[1] |= self::chrToInt($in[3]) << 24;
            case 3:
                $b[1] |= self::chrToInt($in[2]) << 16;
            case 2:
                $b[1] |= self::chrToInt($in[1]) << 8;
            case 1:
                $b[1] |= self::chrToInt($in[0]);
            case 0:
                break;
        }
        // See docblock for why the 0th index gets the higher bits.

        # v3 ^= b;
        $v[6] ^= $b[0];
        $v[7] ^= $b[1];

        # SIPROUND;
        # SIPROUND;
        $v = self::sipRound($v);
        $v = self::sipRound($v);

        # v0 ^= b;
        $v[0] ^= $b[0];
        $v[1] ^= $b[1];

        // Flip the lower 8 bits of v2 which is ($v[4], $v[5]) in our implementation
        # v2 ^= 0xff;
        $v[5] ^= 0xff;

        # SIPROUND;
        # SIPROUND;
        # SIPROUND;
        # SIPROUND;
        $v = self::sipRound($v);
        $v = self::sipRound($v);
        $v = self::sipRound($v);
        $v = self::sipRound($v);

        # b = v0 ^ v1 ^ v2 ^ v3;
        # STORE64_LE( out, b );
        return  self::store32_le($v[1] ^ $v[3] ^ $v[5] ^ $v[7]) .
            self::store32_le($v[0] ^ $v[2] ^ $v[4] ^ $v[6]);
    }
}

• [D] Base64
• [D] ChaCha20
• [D] Curve25519
• [D] Poly1305
• [D] SecretStream
• [F] BLAKE2b.php
  Delete
• [F] ChaCha20.php
  Delete
• [F] Curve25519.php
  Delete
• [F] Ed25519.php
  Delete
• [F] HChaCha20.php
  Delete
• [F] HSalsa20.php
  Delete
• [F] Poly1305.php
  Delete
• [F] Ristretto255.php
  Delete
• [F] Salsa20.php
  Delete
• [F] SipHash.php
  Delete
• [F] Util.php
  Delete
• [F] X25519.php
  Delete
• [F] XChaCha20.php
  Delete
• [F] XSalsa20.php
  Delete

About Section

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.

FAQ Section

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?

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