/home/kueuepay/public_html/vendor/paragonie/sodium_compat/src/Core/BLAKE2b.php
<?php

if (class_exists('ParagonIE_Sodium_Core_BLAKE2b', false)) {
    return;
}

/**
 * Class ParagonIE_Sodium_Core_BLAKE2b
 *
 * Based on the work of Devi Mandiri in devi/salt.
 */
abstract class ParagonIE_Sodium_Core_BLAKE2b extends ParagonIE_Sodium_Core_Util
{
    /**
     * @var SplFixedArray
     */
    protected static $iv;

    /**
     * @var array<int, array<int, int>>
     */
    protected static $sigma = array(
        array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
        array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3),
        array( 11,  8, 12,  0,  5,  2, 15, 13, 10, 14,  3,  6,  7,  1,  9,  4),
        array(  7,  9,  3,  1, 13, 12, 11, 14,  2,  6,  5, 10,  4,  0, 15,  8),
        array(  9,  0,  5,  7,  2,  4, 10, 15, 14,  1, 11, 12,  6,  8,  3, 13),
        array(  2, 12,  6, 10,  0, 11,  8,  3,  4, 13,  7,  5, 15, 14,  1,  9),
        array( 12,  5,  1, 15, 14, 13,  4, 10,  0,  7,  6,  3,  9,  2,  8, 11),
        array( 13, 11,  7, 14, 12,  1,  3,  9,  5,  0, 15,  4,  8,  6,  2, 10),
        array(  6, 15, 14,  9, 11,  3,  0,  8, 12,  2, 13,  7,  1,  4, 10,  5),
        array( 10,  2,  8,  4,  7,  6,  1,  5, 15, 11,  9, 14,  3, 12, 13 , 0),
        array(  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15),
        array( 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3)
    );

    const BLOCKBYTES = 128;
    const OUTBYTES   = 64;
    const KEYBYTES   = 64;

    /**
     * Turn two 32-bit integers into a fixed array representing a 64-bit integer.
     *
     * @internal You should not use this directly from another application
     *
     * @param int $high
     * @param int $low
     * @return SplFixedArray
     * @psalm-suppress MixedAssignment
     */
    public static function new64($high, $low)
    {
        if (PHP_INT_SIZE === 4) {
            throw new SodiumException("Error, use 32-bit");
        }
        $i64 = new SplFixedArray(2);
        $i64[0] = $high & 0xffffffff;
        $i64[1] = $low & 0xffffffff;
        return $i64;
    }

    /**
     * Convert an arbitrary number into an SplFixedArray of two 32-bit integers
     * that represents a 64-bit integer.
     *
     * @internal You should not use this directly from another application
     *
     * @param int $num
     * @return SplFixedArray
     */
    protected static function to64($num)
    {
        list($hi, $lo) = self::numericTo64BitInteger($num);
        return self::new64($hi, $lo);
    }

    /**
     * Adds two 64-bit integers together, returning their sum as a SplFixedArray
     * containing two 32-bit integers (representing a 64-bit integer).
     *
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param SplFixedArray $y
     * @return SplFixedArray
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedOperand
     */
    protected static function add64($x, $y)
    {
        if (PHP_INT_SIZE === 4) {
            throw new SodiumException("Error, use 32-bit");
        }
        $l = ($x[1] + $y[1]) & 0xffffffff;
        return self::new64(
            (int) ($x[0] + $y[0] + (
                ($l < $x[1]) ? 1 : 0
            )),
            (int) $l
        );
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param SplFixedArray $y
     * @param SplFixedArray $z
     * @return SplFixedArray
     */
    protected static function add364($x, $y, $z)
    {
        return self::add64($x, self::add64($y, $z));
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param SplFixedArray $y
     * @return SplFixedArray
     * @throws SodiumException
     * @throws TypeError
     */
    protected static function xor64(SplFixedArray $x, SplFixedArray $y)
    {
        if (PHP_INT_SIZE === 4) {
            throw new SodiumException("Error, use 32-bit");
        }
        if (!is_numeric($x[0])) {
            throw new SodiumException('x[0] is not an integer');
        }
        if (!is_numeric($x[1])) {
            throw new SodiumException('x[1] is not an integer');
        }
        if (!is_numeric($y[0])) {
            throw new SodiumException('y[0] is not an integer');
        }
        if (!is_numeric($y[1])) {
            throw new SodiumException('y[1] is not an integer');
        }
        return self::new64(
            (int) (($x[0] ^ $y[0]) & 0xffffffff),
            (int) (($x[1] ^ $y[1]) & 0xffffffff)
        );
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param int $c
     * @return SplFixedArray
     * @psalm-suppress MixedAssignment
     */
    public static function rotr64($x, $c)
    {
        if (PHP_INT_SIZE === 4) {
            throw new SodiumException("Error, use 32-bit");
        }
        if ($c >= 64) {
            $c %= 64;
        }
        if ($c >= 32) {
            /** @var int $tmp */
            $tmp = $x[0];
            $x[0] = $x[1];
            $x[1] = $tmp;
            $c -= 32;
        }
        if ($c === 0) {
            return $x;
        }

        $l0 = 0;
        $c = 64 - $c;

        /** @var int $c */
        if ($c < 32) {
            $h0 = ((int) ($x[0]) << $c) | (
                (
                    (int) ($x[1]) & ((1 << $c) - 1)
                        <<
                    (32 - $c)
                ) >> (32 - $c)
            );
            $l0 = (int) ($x[1]) << $c;
        } else {
            $h0 = (int) ($x[1]) << ($c - 32);
        }

        $h1 = 0;
        $c1 = 64 - $c;

        if ($c1 < 32) {
            $h1 = (int) ($x[0]) >> $c1;
            $l1 = ((int) ($x[1]) >> $c1) | ((int) ($x[0]) & ((1 << $c1) - 1)) << (32 - $c1);
        } else {
            $l1 = (int) ($x[0]) >> ($c1 - 32);
        }

        return self::new64($h0 | $h1, $l0 | $l1);
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @return int
     * @psalm-suppress MixedOperand
     */
    protected static function flatten64($x)
    {
        return (int) ($x[0] * 4294967296 + $x[1]);
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param int $i
     * @return SplFixedArray
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedArrayOffset
     */
    protected static function load64(SplFixedArray $x, $i)
    {
        /** @var int $l */
        $l = (int) ($x[$i])
             | ((int) ($x[$i+1]) << 8)
             | ((int) ($x[$i+2]) << 16)
             | ((int) ($x[$i+3]) << 24);
        /** @var int $h */
        $h = (int) ($x[$i+4])
             | ((int) ($x[$i+5]) << 8)
             | ((int) ($x[$i+6]) << 16)
             | ((int) ($x[$i+7]) << 24);
        return self::new64($h, $l);
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $x
     * @param int $i
     * @param SplFixedArray $u
     * @return void
     * @psalm-suppress MixedAssignment
     */
    protected static function store64(SplFixedArray $x, $i, SplFixedArray $u)
    {
        $maxLength = $x->getSize() - 1;
        for ($j = 0; $j < 8; ++$j) {
            /*
               [0, 1, 2, 3, 4, 5, 6, 7]
                    ... becomes ...
               [0, 0, 0, 0, 1, 1, 1, 1]
            */
            /** @var int $uIdx */
            $uIdx = ((7 - $j) & 4) >> 2;
            $x[$i]   = ((int) ($u[$uIdx]) & 0xff);
            if (++$i > $maxLength) {
                return;
            }
            /** @psalm-suppress MixedOperand */
            $u[$uIdx] >>= 8;
        }
    }

    /**
     * This just sets the $iv static variable.
     *
     * @internal You should not use this directly from another application
     *
     * @return void
     */
    public static function pseudoConstructor()
    {
        static $called = false;
        if ($called) {
            return;
        }
        self::$iv = new SplFixedArray(8);
        self::$iv[0] = self::new64(0x6a09e667, 0xf3bcc908);
        self::$iv[1] = self::new64(0xbb67ae85, 0x84caa73b);
        self::$iv[2] = self::new64(0x3c6ef372, 0xfe94f82b);
        self::$iv[3] = self::new64(0xa54ff53a, 0x5f1d36f1);
        self::$iv[4] = self::new64(0x510e527f, 0xade682d1);
        self::$iv[5] = self::new64(0x9b05688c, 0x2b3e6c1f);
        self::$iv[6] = self::new64(0x1f83d9ab, 0xfb41bd6b);
        self::$iv[7] = self::new64(0x5be0cd19, 0x137e2179);

        $called = true;
    }

    /**
     * Returns a fresh BLAKE2 context.
     *
     * @internal You should not use this directly from another application
     *
     * @return SplFixedArray
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     */
    protected static function context()
    {
        $ctx    = new SplFixedArray(6);
        $ctx[0] = new SplFixedArray(8);   // h
        $ctx[1] = new SplFixedArray(2);   // t
        $ctx[2] = new SplFixedArray(2);   // f
        $ctx[3] = new SplFixedArray(256); // buf
        $ctx[4] = 0;                      // buflen
        $ctx[5] = 0;                      // last_node (uint8_t)

        for ($i = 8; $i--;) {
            $ctx[0][$i] = self::$iv[$i];
        }
        for ($i = 256; $i--;) {
            $ctx[3][$i] = 0;
        }

        $zero = self::new64(0, 0);
        $ctx[1][0] = $zero;
        $ctx[1][1] = $zero;
        $ctx[2][0] = $zero;
        $ctx[2][1] = $zero;

        return $ctx;
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $ctx
     * @param SplFixedArray $buf
     * @return void
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     * @psalm-suppress MixedArrayOffset
     */
    protected static function compress(SplFixedArray $ctx, SplFixedArray $buf)
    {
        $m = new SplFixedArray(16);
        $v = new SplFixedArray(16);

        for ($i = 16; $i--;) {
            $m[$i] = self::load64($buf, $i << 3);
        }

        for ($i = 8; $i--;) {
            $v[$i] = $ctx[0][$i];
        }

        $v[ 8] = self::$iv[0];
        $v[ 9] = self::$iv[1];
        $v[10] = self::$iv[2];
        $v[11] = self::$iv[3];

        $v[12] = self::xor64($ctx[1][0], self::$iv[4]);
        $v[13] = self::xor64($ctx[1][1], self::$iv[5]);
        $v[14] = self::xor64($ctx[2][0], self::$iv[6]);
        $v[15] = self::xor64($ctx[2][1], self::$iv[7]);

        for ($r = 0; $r < 12; ++$r) {
            $v = self::G($r, 0, 0, 4, 8, 12, $v, $m);
            $v = self::G($r, 1, 1, 5, 9, 13, $v, $m);
            $v = self::G($r, 2, 2, 6, 10, 14, $v, $m);
            $v = self::G($r, 3, 3, 7, 11, 15, $v, $m);
            $v = self::G($r, 4, 0, 5, 10, 15, $v, $m);
            $v = self::G($r, 5, 1, 6, 11, 12, $v, $m);
            $v = self::G($r, 6, 2, 7, 8, 13, $v, $m);
            $v = self::G($r, 7, 3, 4, 9, 14, $v, $m);
        }

        for ($i = 8; $i--;) {
            $ctx[0][$i] = self::xor64(
                $ctx[0][$i], self::xor64($v[$i], $v[$i+8])
            );
        }
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param int $r
     * @param int $i
     * @param int $a
     * @param int $b
     * @param int $c
     * @param int $d
     * @param SplFixedArray $v
     * @param SplFixedArray $m
     * @return SplFixedArray
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedArrayOffset
     */
    public static function G($r, $i, $a, $b, $c, $d, SplFixedArray $v, SplFixedArray $m)
    {
        $v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][$i << 1]]);
        $v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 32);
        $v[$c] = self::add64($v[$c], $v[$d]);
        $v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 24);
        $v[$a] = self::add364($v[$a], $v[$b], $m[self::$sigma[$r][($i << 1) + 1]]);
        $v[$d] = self::rotr64(self::xor64($v[$d], $v[$a]), 16);
        $v[$c] = self::add64($v[$c], $v[$d]);
        $v[$b] = self::rotr64(self::xor64($v[$b], $v[$c]), 63);
        return $v;
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $ctx
     * @param int $inc
     * @return void
     * @throws SodiumException
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     */
    public static function increment_counter($ctx, $inc)
    {
        if ($inc < 0) {
            throw new SodiumException('Increasing by a negative number makes no sense.');
        }
        $t = self::to64($inc);
        # S->t is $ctx[1] in our implementation

        # S->t[0] = ( uint64_t )( t >> 0 );
        $ctx[1][0] = self::add64($ctx[1][0], $t);

        # S->t[1] += ( S->t[0] < inc );
        if (self::flatten64($ctx[1][0]) < $inc) {
            $ctx[1][1] = self::add64($ctx[1][1], self::to64(1));
        }
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $ctx
     * @param SplFixedArray $p
     * @param int $plen
     * @return void
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     * @psalm-suppress MixedArrayOffset
     * @psalm-suppress MixedOperand
     */
    public static function update(SplFixedArray $ctx, SplFixedArray $p, $plen)
    {
        self::pseudoConstructor();

        $offset = 0;
        while ($plen > 0) {
            $left = $ctx[4];
            $fill = 256 - $left;

            if ($plen > $fill) {
                # memcpy( S->buf + left, in, fill ); /* Fill buffer */
                for ($i = $fill; $i--;) {
                    $ctx[3][$i + $left] = $p[$i + $offset];
                }

                # S->buflen += fill;
                $ctx[4] += $fill;

                # blake2b_increment_counter( S, BLAKE2B_BLOCKBYTES );
                self::increment_counter($ctx, 128);

                # blake2b_compress( S, S->buf ); /* Compress */
                self::compress($ctx, $ctx[3]);

                # memcpy( S->buf, S->buf + BLAKE2B_BLOCKBYTES, BLAKE2B_BLOCKBYTES ); /* Shift buffer left */
                for ($i = 128; $i--;) {
                    $ctx[3][$i] = $ctx[3][$i + 128];
                }

                # S->buflen -= BLAKE2B_BLOCKBYTES;
                $ctx[4] -= 128;

                # in += fill;
                $offset += $fill;

                # inlen -= fill;
                $plen -= $fill;
            } else {
                for ($i = $plen; $i--;) {
                    $ctx[3][$i + $left] = $p[$i + $offset];
                }
                $ctx[4] += $plen;
                $offset += $plen;
                $plen -= $plen;
            }
        }
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $ctx
     * @param SplFixedArray $out
     * @return SplFixedArray
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     * @psalm-suppress MixedArrayOffset
     * @psalm-suppress MixedOperand
     */
    public static function finish(SplFixedArray $ctx, SplFixedArray $out)
    {
        self::pseudoConstructor();
        if ($ctx[4] > 128) {
            self::increment_counter($ctx, 128);
            self::compress($ctx, $ctx[3]);
            $ctx[4] -= 128;
            if ($ctx[4] > 128) {
                throw new SodiumException('Failed to assert that buflen <= 128 bytes');
            }
            for ($i = $ctx[4]; $i--;) {
                $ctx[3][$i] = $ctx[3][$i + 128];
            }
        }

        self::increment_counter($ctx, $ctx[4]);
        $ctx[2][0] = self::new64(0xffffffff, 0xffffffff);

        for ($i = 256 - $ctx[4]; $i--;) {
            $ctx[3][$i+$ctx[4]] = 0;
        }

        self::compress($ctx, $ctx[3]);

        $i = (int) (($out->getSize() - 1) / 8);
        for (; $i >= 0; --$i) {
            self::store64($out, $i << 3, $ctx[0][$i]);
        }
        return $out;
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray|null $key
     * @param int $outlen
     * @param SplFixedArray|null $salt
     * @param SplFixedArray|null $personal
     * @return SplFixedArray
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     * @psalm-suppress MixedArrayOffset
     */
    public static function init(
        $key = null,
        $outlen = 64,
        $salt = null,
        $personal = null
    ) {
        self::pseudoConstructor();
        $klen = 0;

        if ($key !== null) {
            if (count($key) > 64) {
                throw new SodiumException('Invalid key size');
            }
            $klen = count($key);
        }

        if ($outlen > 64) {
            throw new SodiumException('Invalid output size');
        }

        $ctx = self::context();

        $p = new SplFixedArray(64);
        // Zero our param buffer...
        for ($i = 64; --$i;) {
            $p[$i] = 0;
        }

        $p[0] = $outlen; // digest_length
        $p[1] = $klen;   // key_length
        $p[2] = 1;       // fanout
        $p[3] = 1;       // depth

        if ($salt instanceof SplFixedArray) {
            // salt: [32] through [47]
            for ($i = 0; $i < 16; ++$i) {
                $p[32 + $i] = (int) $salt[$i];
            }
        }
        if ($personal instanceof SplFixedArray) {
            // personal: [48] through [63]
            for ($i = 0; $i < 16; ++$i) {
                $p[48 + $i] = (int) $personal[$i];
            }
        }

        $ctx[0][0] = self::xor64(
            $ctx[0][0],
            self::load64($p, 0)
        );
        if ($salt instanceof SplFixedArray || $personal instanceof SplFixedArray) {
            // We need to do what blake2b_init_param() does:
            for ($i = 1; $i < 8; ++$i) {
                $ctx[0][$i] = self::xor64(
                    $ctx[0][$i],
                    self::load64($p, $i << 3)
                );
            }
        }

        if ($klen > 0 && $key instanceof SplFixedArray) {
            $block = new SplFixedArray(128);
            for ($i = 128; $i--;) {
                $block[$i] = 0;
            }
            for ($i = $klen; $i--;) {
                $block[$i] = $key[$i];
            }
            self::update($ctx, $block, 128);
            $ctx[4] = 128;
        }

        return $ctx;
    }

    /**
     * Convert a string into an SplFixedArray of integers
     *
     * @internal You should not use this directly from another application
     *
     * @param string $str
     * @return SplFixedArray
     * @psalm-suppress MixedArgumentTypeCoercion
     */
    public static function stringToSplFixedArray($str = '')
    {
        $values = unpack('C*', $str);
        return SplFixedArray::fromArray(array_values($values));
    }

    /**
     * Convert an SplFixedArray of integers into a string
     *
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $a
     * @return string
     * @throws TypeError
     */
    public static function SplFixedArrayToString(SplFixedArray $a)
    {
        /**
         * @var array<int, int|string> $arr
         */
        $arr = $a->toArray();
        $c = $a->count();
        array_unshift($arr, str_repeat('C', $c));
        return (string) (call_user_func_array('pack', $arr));
    }

    /**
     * @internal You should not use this directly from another application
     *
     * @param SplFixedArray $ctx
     * @return string
     * @throws TypeError
     * @psalm-suppress MixedArgument
     * @psalm-suppress MixedAssignment
     * @psalm-suppress MixedArrayAccess
     * @psalm-suppress MixedArrayAssignment
     * @psalm-suppress MixedArrayOffset
     * @psalm-suppress MixedMethodCall
     */
    public static function contextToString(SplFixedArray $ctx)
    {
        $str = '';
        /** @var array<int, array<int, int>> $ctxA */
        $ctxA = $ctx[0]->toArray();

        # uint64_t h[8];
        for ($i = 0; $i < 8; ++$i) {
            $str .= self::store32_le($ctxA[$i][1]);
            $str .= self::store32_le($ctxA[$i][0]);
        }

        # uint64_t t[2];
        # uint64_t f[2];
        for ($i = 1; $i < 3; ++$i) {
            $ctxA = $ctx[$i]->toArray();
            $str .= self::store32_le($ctxA[0][1]);
            $str .= self::store32_le($ctxA[0][0]);
            $str .= self::store32_le($ctxA[1][1]);
            $str .= self::store32_le($ctxA[1][0]);
        }

        # uint8_t buf[2 * 128];
        $str .= self::SplFixedArrayToString($ctx[3]);

        /** @var int $ctx4 */
        $ctx4 = (int) $ctx[4];

        # size_t buflen;
        $str .= implode('', array(
            self::intToChr($ctx4 & 0xff),
            self::intToChr(($ctx4 >> 8) & 0xff),
            self::intToChr(($ctx4 >> 16) & 0xff),
            self::intToChr(($ctx4 >> 24) & 0xff),
            self::intToChr(($ctx4 >> 32) & 0xff),
            self::intToChr(($ctx4 >> 40) & 0xff),
            self::intToChr(($ctx4 >> 48) & 0xff),
            self::intToChr(($ctx4 >> 56) & 0xff)
        ));
        # uint8_t last_node;
        return $str . self::intToChr($ctx[5]) . str_repeat("\x00", 23);
    }

    /**
     * Creates an SplFixedArray containing other SplFixedArray elements, from
     * a string (compatible with \Sodium\crypto_generichash_{init, update, final})
     *
     * @internal You should not use this directly from another application
     *
     * @param string $string
     * @return SplFixedArray
     * @throws SodiumException
     * @throws TypeError
     * @psalm-suppress MixedArrayAssignment
     */
    public static function stringToContext($string)
    {
        $ctx = self::context();

        # uint64_t h[8];
        for ($i = 0; $i < 8; ++$i) {
            $ctx[0][$i] = SplFixedArray::fromArray(
                array(
                    self::load_4(
                        self::substr($string, (($i << 3) + 4), 4)
                    ),
                    self::load_4(
                        self::substr($string, (($i << 3) + 0), 4)
                    )
                )
            );
        }

        # uint64_t t[2];
        # uint64_t f[2];
        for ($i = 1; $i < 3; ++$i) {
            $ctx[$i][1] = SplFixedArray::fromArray(
                array(
                    self::load_4(self::substr($string, 76 + (($i - 1) << 4), 4)),
                    self::load_4(self::substr($string, 72 + (($i - 1) << 4), 4))
                )
            );
            $ctx[$i][0] = SplFixedArray::fromArray(
                array(
                    self::load_4(self::substr($string, 68 + (($i - 1) << 4), 4)),
                    self::load_4(self::substr($string, 64 + (($i - 1) << 4), 4))
                )
            );
        }

        # uint8_t buf[2 * 128];
        $ctx[3] = self::stringToSplFixedArray(self::substr($string, 96, 256));

        # uint8_t buf[2 * 128];
        $int = 0;
        for ($i = 0; $i < 8; ++$i) {
            $int |= self::chrToInt($string[352 + $i]) << ($i << 3);
        }
        $ctx[4] = $int;

        return $ctx;
    }
}
Service
top

Our Services: Streamlining Your Payment Experience with Excellence

Discover how our services are designed to enhance your NFC Pay experience with convenience, security, and innovative solutions. From managing transactions to secure payments, we are dedicated to providing seamless support every step of the way.

Secure Card Storage

Easily save your credit and debit card details within our app for quick and secure transactions. This feature ensures that your payment information is protected with advanced encryption and can be used for future purchases with just a tap.

Effortless Money Transfers

Transfer funds quickly and securely between users with our streamlined money transfer service. Simply select the recipient, enter the amount, and authorize the transaction for instant, hassle-free transfers.

Merchant Account Setup

Activate your merchant account effortlessly to start receiving payments. Our intuitive setup process ensures that you can begin accepting transactions smoothly, helping your business thrive with minimal setup time.

Real-Time Transaction Tracking

Keep track of all your transactions in real time through our app. Monitor payment statuses, view transaction history, and manage your account efficiently, ensuring complete control over your financial activities.

Customer Support

Our dedicated support team is available to assist you with any queries or issues. Whether you need help with setting up your account or resolving transaction-related questions, we’re here to provide prompt and reliable assistance.