<?php

/**
 * Prime Finite Fields
 *
 * PHP version 5 and 7
 *
 * @author    Jim Wigginton <terrafrost@php.net>
 * @copyright 2017 Jim Wigginton
 * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
 */

namespace phpseclib3\Math\PrimeField;

use phpseclib3\Common\Functions\Strings;
use phpseclib3\Math\BigInteger;
use phpseclib3\Math\Common\FiniteField\Integer as Base;

/**
 * Prime Finite Fields
 *
 * @author  Jim Wigginton <terrafrost@php.net>
 */
class Integer extends Base
{
    /**
     * Holds the PrimeField's value
     *
     * @var BigInteger
     */
    protected $value;

    /**
     * Keeps track of current instance
     *
     * @var int
     */
    protected $instanceID;

    /**
     * Holds the PrimeField's modulo
     *
     * @var array<int, BigInteger>
     */
    protected static $modulo;

    /**
     * Holds a pre-generated function to perform modulo reductions
     *
     * @var array<int, callable(BigInteger):BigInteger>
     */
    protected static $reduce;

    /**
     * Zero
     *
     * @var BigInteger
     */
    protected static $zero;

    /**
     * Default constructor
     *
     * @param int $instanceID
     */
    public function __construct($instanceID, BigInteger $num = null)
    {
        $this->instanceID = $instanceID;
        if (!isset($num)) {
            $this->value = clone static::$zero[static::class];
        } else {
            $reduce = static::$reduce[$instanceID];
            $this->value = $reduce($num);
        }
    }

    /**
     * Set the modulo for a given instance
     *
     * @param int $instanceID
     * @return void
     */
    public static function setModulo($instanceID, BigInteger $modulo)
    {
        static::$modulo[$instanceID] = $modulo;
    }

    /**
     * Set the modulo for a given instance
     *
     * @param int $instanceID
     * @return void
     */
    public static function setRecurringModuloFunction($instanceID, callable $function)
    {
        static::$reduce[$instanceID] = $function;
        if (!isset(static::$zero[static::class])) {
            static::$zero[static::class] = new BigInteger();
        }
    }

    /**
     * Delete the modulo for a given instance
     */
    public static function cleanupCache($instanceID)
    {
        unset(static::$modulo[$instanceID]);
        unset(static::$reduce[$instanceID]);
    }

    /**
     * Returns the modulo
     *
     * @param int $instanceID
     * @return BigInteger
     */
    public static function getModulo($instanceID)
    {
        return static::$modulo[$instanceID];
    }

    /**
     * Tests a parameter to see if it's of the right instance
     *
     * Throws an exception if the incorrect class is being utilized
     *
     * @return void
     */
    public static function checkInstance(self $x, self $y)
    {
        if ($x->instanceID != $y->instanceID) {
            throw new \UnexpectedValueException('The instances of the two PrimeField\Integer objects do not match');
        }
    }

    /**
     * Tests the equality of two numbers.
     *
     * @return bool
     */
    public function equals(self $x)
    {
        static::checkInstance($this, $x);

        return $this->value->equals($x->value);
    }

    /**
     * Compares two numbers.
     *
     * @return int
     */
    public function compare(self $x)
    {
        static::checkInstance($this, $x);

        return $this->value->compare($x->value);
    }

    /**
     * Adds two PrimeFieldIntegers.
     *
     * @return static
     */
    public function add(self $x)
    {
        static::checkInstance($this, $x);

        $temp = new static($this->instanceID);
        $temp->value = $this->value->add($x->value);
        if ($temp->value->compare(static::$modulo[$this->instanceID]) >= 0) {
            $temp->value = $temp->value->subtract(static::$modulo[$this->instanceID]);
        }

        return $temp;
    }

    /**
     * Subtracts two PrimeFieldIntegers.
     *
     * @return static
     */
    public function subtract(self $x)
    {
        static::checkInstance($this, $x);

        $temp = new static($this->instanceID);
        $temp->value = $this->value->subtract($x->value);
        if ($temp->value->isNegative()) {
            $temp->value = $temp->value->add(static::$modulo[$this->instanceID]);
        }

        return $temp;
    }

    /**
     * Multiplies two PrimeFieldIntegers.
     *
     * @return static
     */
    public function multiply(self $x)
    {
        static::checkInstance($this, $x);

        return new static($this->instanceID, $this->value->multiply($x->value));
    }

    /**
     * Divides two PrimeFieldIntegers.
     *
     * @return static
     */
    public function divide(self $x)
    {
        static::checkInstance($this, $x);

        $denominator = $x->value->modInverse(static::$modulo[$this->instanceID]);
        return new static($this->instanceID, $this->value->multiply($denominator));
    }

    /**
     * Performs power operation on a PrimeFieldInteger.
     *
     * @return static
     */
    public function pow(BigInteger $x)
    {
        $temp = new static($this->instanceID);
        $temp->value = $this->value->powMod($x, static::$modulo[$this->instanceID]);

        return $temp;
    }

    /**
     * Calculates the square root
     *
     * @link https://en.wikipedia.org/wiki/Tonelli%E2%80%93Shanks_algorithm
     * @return static|false
     */
    public function squareRoot()
    {
        static $one, $two;
        if (!isset($one)) {
            $one = new BigInteger(1);
            $two = new BigInteger(2);
        }
        $reduce = static::$reduce[$this->instanceID];
        $p_1 = static::$modulo[$this->instanceID]->subtract($one);
        $q = clone $p_1;
        $s = BigInteger::scan1divide($q);
        list($pow) = $p_1->divide($two);
        for ($z = $one; !$z->equals(static::$modulo[$this->instanceID]); $z = $z->add($one)) {
            $temp = $z->powMod($pow, static::$modulo[$this->instanceID]);
            if ($temp->equals($p_1)) {
                break;
            }
        }

        $m = new BigInteger($s);
        $c = $z->powMod($q, static::$modulo[$this->instanceID]);
        $t = $this->value->powMod($q, static::$modulo[$this->instanceID]);
        list($temp) = $q->add($one)->divide($two);
        $r = $this->value->powMod($temp, static::$modulo[$this->instanceID]);

        while (!$t->equals($one)) {
            for ($i = clone $one; $i->compare($m) < 0; $i = $i->add($one)) {
                if ($t->powMod($two->pow($i), static::$modulo[$this->instanceID])->equals($one)) {
                    break;
                }
            }

            if ($i->compare($m) == 0) {
                return false;
            }
            $b = $c->powMod($two->pow($m->subtract($i)->subtract($one)), static::$modulo[$this->instanceID]);
            $m = $i;
            $c = $reduce($b->multiply($b));
            $t = $reduce($t->multiply($c));
            $r = $reduce($r->multiply($b));
        }

        return new static($this->instanceID, $r);
    }

    /**
     * Is Odd?
     *
     * @return bool
     */
    public function isOdd()
    {
        return $this->value->isOdd();
    }

    /**
     * Negate
     *
     * A negative number can be written as 0-12. With modulos, 0 is the same thing as the modulo
     * so 0-12 is the same thing as modulo-12
     *
     * @return static
     */
    public function negate()
    {
        return new static($this->instanceID, static::$modulo[$this->instanceID]->subtract($this->value));
    }

    /**
     * Converts an Integer to a byte string (eg. base-256).
     *
     * @return string
     */
    public function toBytes()
    {
        if (isset(static::$modulo[$this->instanceID])) {
            $length = static::$modulo[$this->instanceID]->getLengthInBytes();
            return str_pad($this->value->toBytes(), $length, "\0", STR_PAD_LEFT);
        }
        return $this->value->toBytes();
    }

    /**
     * Converts an Integer to a hex string (eg. base-16).
     *
     * @return string
     */
    public function toHex()
    {
        return Strings::bin2hex($this->toBytes());
    }

    /**
     * Converts an Integer to a bit string (eg. base-2).
     *
     * @return string
     */
    public function toBits()
    {
        // return $this->value->toBits();
        static $length;
        if (!isset($length)) {
            $length = static::$modulo[$this->instanceID]->getLength();
        }

        return str_pad($this->value->toBits(), $length, '0', STR_PAD_LEFT);
    }

    /**
     * Returns the w-ary non-adjacent form (wNAF)
     *
     * @param int $w optional
     * @return array<int, int>
     */
    public function getNAF($w = 1)
    {
        $w++;

        $mask = new BigInteger((1 << $w) - 1);
        $sub = new BigInteger(1 << $w);
        //$sub = new BigInteger(1 << ($w - 1));
        $d = $this->toBigInteger();
        $d_i = [];

        $i = 0;
        while ($d->compare(static::$zero[static::class]) > 0) {
            if ($d->isOdd()) {
                // start mods

                $bigInteger = $d->testBit($w - 1) ?
                    $d->bitwise_and($mask)->subtract($sub) :
                    //$sub->subtract($d->bitwise_and($mask)) :
                    $d->bitwise_and($mask);
                // end mods
                $d = $d->subtract($bigInteger);
                $d_i[$i] = (int) $bigInteger->toString();
            } else {
                $d_i[$i] = 0;
            }
            $shift = !$d->equals(static::$zero[static::class]) && $d->bitwise_and($mask)->equals(static::$zero[static::class]) ? $w : 1; // $w or $w + 1?
            $d = $d->bitwise_rightShift($shift);
            while (--$shift > 0) {
                $d_i[++$i] = 0;
            }
            $i++;
        }

        return $d_i;
    }

    /**
     * Converts an Integer to a BigInteger
     *
     * @return BigInteger
     */
    public function toBigInteger()
    {
        return clone $this->value;
    }

    /**
     *  __toString() magic method
     *
     * @return string
     */
    public function __toString()
    {
        return (string) $this->value;
    }

    /**
     *  __debugInfo() magic method
     *
     * @return array
     */
    public function __debugInfo()
    {
        return ['value' => $this->toHex()];
    }
}

• [F] Integer.php
  Delete

Service Section

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.