<?php

/**
 * EC Private Key
 *
 * @author    Jim Wigginton <terrafrost@php.net>
 * @copyright 2015 Jim Wigginton
 * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
 * @link      http://phpseclib.sourceforge.net
 */

namespace phpseclib3\Crypt\EC;

use phpseclib3\Common\Functions\Strings;
use phpseclib3\Crypt\Common;
use phpseclib3\Crypt\EC;
use phpseclib3\Crypt\EC\BaseCurves\Montgomery as MontgomeryCurve;
use phpseclib3\Crypt\EC\BaseCurves\TwistedEdwards as TwistedEdwardsCurve;
use phpseclib3\Crypt\EC\Curves\Curve25519;
use phpseclib3\Crypt\EC\Curves\Ed25519;
use phpseclib3\Crypt\EC\Formats\Keys\PKCS1;
use phpseclib3\Crypt\EC\Formats\Signature\ASN1 as ASN1Signature;
use phpseclib3\Crypt\Hash;
use phpseclib3\Exception\UnsupportedOperationException;
use phpseclib3\Math\BigInteger;

/**
 * EC Private Key
 *
 * @author  Jim Wigginton <terrafrost@php.net>
 */
final class PrivateKey extends EC implements Common\PrivateKey
{
    use Common\Traits\PasswordProtected;

    /**
     * Private Key dA
     *
     * sign() converts this to a BigInteger so one might wonder why this is a FiniteFieldInteger instead of
     * a BigInteger. That's because a FiniteFieldInteger, when converted to a byte string, is null padded by
     * a certain amount whereas a BigInteger isn't.
     *
     * @var object
     */
    protected $dA;

    /**
     * @var string
     */
    protected $secret;

    /**
     * Multiplies an encoded point by the private key
     *
     * Used by ECDH
     *
     * @param string $coordinates
     * @return string
     */
    public function multiply($coordinates)
    {
        if ($this->curve instanceof MontgomeryCurve) {
            if ($this->curve instanceof Curve25519 && self::$engines['libsodium']) {
                return sodium_crypto_scalarmult($this->dA->toBytes(), $coordinates);
            }

            $point = [$this->curve->convertInteger(new BigInteger(strrev($coordinates), 256))];
            $point = $this->curve->multiplyPoint($point, $this->dA);
            return strrev($point[0]->toBytes(true));
        }
        if (!$this->curve instanceof TwistedEdwardsCurve) {
            $coordinates = "\0$coordinates";
        }
        $point = PKCS1::extractPoint($coordinates, $this->curve);
        $point = $this->curve->multiplyPoint($point, $this->dA);
        if ($this->curve instanceof TwistedEdwardsCurve) {
            return $this->curve->encodePoint($point);
        }
        if (empty($point)) {
            throw new \RuntimeException('The infinity point is invalid');
        }
        return "\4" . $point[0]->toBytes(true) . $point[1]->toBytes(true);
    }

    /**
     * Create a signature
     *
     * @see self::verify()
     * @param string $message
     * @return mixed
     */
    public function sign($message)
    {
        if ($this->curve instanceof MontgomeryCurve) {
            throw new UnsupportedOperationException('Montgomery Curves cannot be used to create signatures');
        }

        $dA = $this->dA;
        $order = $this->curve->getOrder();

        $shortFormat = $this->shortFormat;
        $format = $this->sigFormat;
        if ($format === false) {
            return false;
        }

        if ($this->curve instanceof TwistedEdwardsCurve) {
            if ($this->curve instanceof Ed25519 && self::$engines['libsodium'] && !isset($this->context)) {
                $result = sodium_crypto_sign_detached($message, $this->withPassword()->toString('libsodium'));
                return $shortFormat == 'SSH2' ? Strings::packSSH2('ss', 'ssh-' . strtolower($this->getCurve()), $result) : $result;
            }

            // contexts (Ed25519ctx) are supported but prehashing (Ed25519ph) is not.
            // quoting https://tools.ietf.org/html/rfc8032#section-8.5 ,
            // "The Ed25519ph and Ed448ph variants ... SHOULD NOT be used"
            $A = $this->curve->encodePoint($this->QA);
            $curve = $this->curve;
            $hash = new Hash($curve::HASH);

            $secret = substr($hash->hash($this->secret), $curve::SIZE);

            if ($curve instanceof Ed25519) {
                $dom = !isset($this->context) ? '' :
                    'SigEd25519 no Ed25519 collisions' . "\0" . chr(strlen($this->context)) . $this->context;
            } else {
                $context = isset($this->context) ? $this->context : '';
                $dom = 'SigEd448' . "\0" . chr(strlen($context)) . $context;
            }
            // SHA-512(dom2(F, C) || prefix || PH(M))
            $r = $hash->hash($dom . $secret . $message);
            $r = strrev($r);
            $r = new BigInteger($r, 256);
            list(, $r) = $r->divide($order);
            $R = $curve->multiplyPoint($curve->getBasePoint(), $r);
            $R = $curve->encodePoint($R);
            $k = $hash->hash($dom . $R . $A . $message);
            $k = strrev($k);
            $k = new BigInteger($k, 256);
            list(, $k) = $k->divide($order);
            $S = $k->multiply($dA)->add($r);
            list(, $S) = $S->divide($order);
            $S = str_pad(strrev($S->toBytes()), $curve::SIZE, "\0");
            return $shortFormat == 'SSH2' ? Strings::packSSH2('ss', 'ssh-' . strtolower($this->getCurve()), $R . $S) : $R . $S;
        }

        if (self::$engines['OpenSSL'] && in_array($this->hash->getHash(), openssl_get_md_methods())) {
            $signature = '';
            // altho PHP's OpenSSL bindings only supported EC key creation in PHP 7.1 they've long
            // supported signing / verification
            // we use specified curves to avoid issues with OpenSSL possibly not supporting a given named curve;
            // doing this may mean some curve-specific optimizations can't be used but idk if OpenSSL even
            // has curve-specific optimizations
            $result = openssl_sign($message, $signature, $this->withPassword()->toString('PKCS8', ['namedCurve' => false]), $this->hash->getHash());

            if ($result) {
                if ($shortFormat == 'ASN1') {
                    return $signature;
                }

                extract(ASN1Signature::load($signature));

                return $shortFormat == 'SSH2' ? $format::save($r, $s, $this->getCurve()) : $format::save($r, $s);
            }
        }

        $e = $this->hash->hash($message);
        $e = new BigInteger($e, 256);

        $Ln = $this->hash->getLength() - $order->getLength();
        $z = $Ln > 0 ? $e->bitwise_rightShift($Ln) : $e;

        while (true) {
            $k = BigInteger::randomRange(self::$one, $order->subtract(self::$one));
            list($x, $y) = $this->curve->multiplyPoint($this->curve->getBasePoint(), $k);
            $x = $x->toBigInteger();
            list(, $r) = $x->divide($order);
            if ($r->equals(self::$zero)) {
                continue;
            }
            $kinv = $k->modInverse($order);
            $temp = $z->add($dA->multiply($r));
            $temp = $kinv->multiply($temp);
            list(, $s) = $temp->divide($order);
            if (!$s->equals(self::$zero)) {
                break;
            }
        }

        // the following is an RFC6979 compliant implementation of deterministic ECDSA
        // it's unused because it's mainly intended for use when a good CSPRNG isn't
        // available. if phpseclib's CSPRNG isn't good then even key generation is
        // suspect
        /*
        // if this were actually being used it'd probably be better if this lived in load() and createKey()
        $this->q = $this->curve->getOrder();
        $dA = $this->dA->toBigInteger();
        $this->x = $dA;

        $h1 = $this->hash->hash($message);
        $k = $this->computek($h1);
        list($x, $y) = $this->curve->multiplyPoint($this->curve->getBasePoint(), $k);
        $x = $x->toBigInteger();
        list(, $r) = $x->divide($this->q);
        $kinv = $k->modInverse($this->q);
        $h1 = $this->bits2int($h1);
        $temp = $h1->add($dA->multiply($r));
        $temp = $kinv->multiply($temp);
        list(, $s) = $temp->divide($this->q);
        */

        return $shortFormat == 'SSH2' ? $format::save($r, $s, $this->getCurve()) : $format::save($r, $s);
    }

    /**
     * Returns the private key
     *
     * @param string $type
     * @param array $options optional
     * @return string
     */
    public function toString($type, array $options = [])
    {
        $type = self::validatePlugin('Keys', $type, 'savePrivateKey');

        return $type::savePrivateKey($this->dA, $this->curve, $this->QA, $this->secret, $this->password, $options);
    }

    /**
     * Returns the public key
     *
     * @see self::getPrivateKey()
     * @return mixed
     */
    public function getPublicKey()
    {
        $format = 'PKCS8';
        if ($this->curve instanceof MontgomeryCurve) {
            $format = 'MontgomeryPublic';
        }

        $type = self::validatePlugin('Keys', $format, 'savePublicKey');

        $key = $type::savePublicKey($this->curve, $this->QA);
        $key = EC::loadFormat($format, $key);
        if ($this->curve instanceof MontgomeryCurve) {
            return $key;
        }
        $key = $key
            ->withHash($this->hash->getHash())
            ->withSignatureFormat($this->shortFormat);
        if ($this->curve instanceof TwistedEdwardsCurve) {
            $key = $key->withContext($this->context);
        }
        return $key;
    }
}

• [D] BaseCurves
• [D] Curves
• [D] Formats
• [F] Parameters.php
  Delete
• [F] PrivateKey.php
  Delete
• [F] PublicKey.php
  Delete

How To Payment

Simple Steps to Complete Your Payment Securely and Efficiently

Making a payment on our website is quick and secure. Start by logging in or creating an account. Select your preferred payment method, input the required details, and review the information. Once you confirm everything is correct, click on the "Submit Payment" button. You’ll receive instant confirmation and can track your payment status through your account dashboard. It’s an easy and secure process.

• Go to the Payment Section: Access the payment area on our website or app.
• Choose Your Payment Method: Select your preferred payment option.
• Enter Payment Details: Provide the necessary payment information.
• Verify Your Information: Check that all details are correct.
• Confirm Your Payment: Click "Submit Payment" to complete the transaction.