/**
* @param CurveFpInterface $curve
* @return mixed
*/
public static function getByteSize(CurveFpInterface $curve)
{
if ($curve instanceof NamedCurveFp && array_key_exists($curve->getName(), self::$sizeMap)) {
return self::$sizeMap[$curve->getName()];
}
throw new \RuntimeException('Unsupported curve type.');
}
/**
* @param CurveFpInterface $curve
* @param string $data
* @return PointInterface
*/
public function unserialize(CurveFpInterface $curve, $data)
{
if (substr($data, 0, 2) != '04') {
throw new \InvalidArgumentException('Invalid data: only uncompressed keys are supported.');
}
$data = substr($data, 2);
$dataLength = strlen($data);
$x = $this->adapter->hexDec(substr($data, 0, $dataLength / 2));
$y = $this->adapter->hexDec(substr($data, $dataLength / 2));
return $curve->getPoint($x, $y);
}
/**
* {@inheritDoc}
* @see \Mdanter\Ecc\PointInterface::getDouble()
*/
public function getDouble()
{
if ($this->isInfinity()) {
return $this->curve->getInfinity();
}
$math = $this->adapter;
$modMath = $this->modAdapter;
$a = $this->curve->getA();
$threeX2 = $math->mul(3, $math->pow($this->x, 2));
$tangent = $modMath->div($math->add($threeX2, $a), $math->mul(2, $this->y));
$x3 = $modMath->sub($math->pow($tangent, 2), $math->mul(2, $this->x));
$y3 = $modMath->sub($math->mul($tangent, $math->sub($this->x, $x3)), $this->y);
return new self($this->adapter, $this->curve, $x3, $y3, $this->order);
}
/**
* {@inheritDoc}
* @see \Mdanter\Ecc\CurveFpInterface::cmp()
*/
public function cmp(CurveFpInterface $other)
{
$math = $this->adapter;
$equal = $math->cmp($this->a, $other->getA()) == 0;
$equal &= $math->cmp($this->b, $other->getB()) == 0;
$equal &= $math->cmp($this->prime, $other->getPrime()) == 0;
return $equal ? 0 : 1;
}
/**
* {@inheritDoc}
* @see \Mdanter\Ecc\MathAdapterInterface::getPrimeFieldArithmetic()
*/
public function getPrimeFieldArithmetic(CurveFpInterface $curve)
{
return $this->getModularArithmetic($curve->getPrime());
}
private function add(MathAdapterInterface $math, CurveFpInterface $c, $x1, $y1, $x2, $y2, $x3, $y3)
{
$p1 = $c->getPoint($x1, $y1);
$p2 = $c->getPoint($x2, $y2);
$p3 = $p1->add($p2);
$this->assertEquals($math->mod($p3->getX(), 23), $x3);
$this->assertEquals($math->mod($p3->getY(), 23), $y3);
}
