php-bitpay-client/src/Bitpay/PublicKey.php

162 lines
4.0 KiB
PHP

<?php
/**
* The MIT License (MIT)
*
* Copyright (c) 2014 BitPay, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
namespace Bitpay;
use Bitpay\Util\Gmp;
use Bitpay\Util\Secp256k1;
use Bitpay\Util\Util;
/**
* @package Bitcore
*/
class PublicKey extends Key
{
/**
* @var SinKey
*/
protected $sin;
/**
* @var PrivateKey
*/
protected $privateKey;
/**
* Returns the compressed public key value
*
* @return string
*/
public function __toString()
{
if (is_null($this->x)) {
return '';
}
if (gmp_strval(gmp_mod('0x'.$this->y, '0x02')) == '1') {
return sprintf('03%s', $this->x);
} else {
return sprintf('02%s', $this->x);
}
}
/**
* @param PrivateKey
*/
public static function createFromPrivateKey(PrivateKey $private)
{
$public = new self();
$public->setPrivateKey($private);
return $public;
}
/**
* @return KeyInterface
*/
public function setPrivateKey(PrivateKey $privateKey)
{
$this->privateKey = $privateKey;
return $this;
}
/**
* Generates an uncompressed and compressed EC public key.
*
* @param \Bitpay\PrivateKey $privateKey
*
* @return Bitpay\PublicKey
*/
public function generate()
{
if (is_null($this->privateKey)) {
throw new \Exception('Please `setPrivateKey` before you generate a public key');
}
if (!$this->privateKey->isGenerated()) {
$this->privateKey->generate();
}
if (!$this->privateKey->isValid()) {
throw new \Exception('Private Key is invalid and cannot be used to generate a public key');
}
$point = new Point(
'0x'.substr(Secp256k1::G, 0, 62),
'0x'.substr(Secp256k1::G, 62, 62)
);
$R = Gmp::doubleAndAdd(
'0x'.$this->privateKey->getHex(),
$point
);
$RxHex = Util::encodeHex($R->getX());
$RyHex = Util::encodeHex($R->getY());
while (strlen($RxHex) < 64) {
$RxHex .= 0;
}
while (strlen($RyHex) < 64) {
$RyHex .= 0;
}
$this->x = $RxHex;
$this->y = $RyHex;
$this->hex = sprintf('04%s%s', $RxHex, $RyHex);
$this->dec = Util::decodeHex(sprintf('04%s%s', $R->getX(), $R->getY()));
return $this;
}
/**
* Checks to see if the public key is not blank and contains
* valid decimal and hex valules for this->hex & this->dec
*
* @return boolean
*/
public function isValid()
{
return ((!empty($this->hex) && !ctype_xdigit($this->hex)) && (!empty($this->dec) && !ctype_digit($this->dec)));
}
/**
* @return SinKey
*/
public function getSin()
{
if (null === $this->sin) {
$this->sin = new SinKey();
$this->sin->setPublicKey($this);
$this->sin->generate();
}
return $this->sin;
}
}