diff options
Diffstat (limited to 'vendor/phpseclib/phpseclib/phpseclib/Crypt/EC/BaseCurves/TwistedEdwards.php')
| -rw-r--r-- | vendor/phpseclib/phpseclib/phpseclib/Crypt/EC/BaseCurves/TwistedEdwards.php | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/vendor/phpseclib/phpseclib/phpseclib/Crypt/EC/BaseCurves/TwistedEdwards.php b/vendor/phpseclib/phpseclib/phpseclib/Crypt/EC/BaseCurves/TwistedEdwards.php new file mode 100644 index 0000000..2521a4c --- /dev/null +++ b/vendor/phpseclib/phpseclib/phpseclib/Crypt/EC/BaseCurves/TwistedEdwards.php @@ -0,0 +1,215 @@ +<?php + +/** + * Curves over a*x^2 + y^2 = 1 + d*x^2*y^2 + * + * http://www.secg.org/SEC2-Ver-1.0.pdf provides for curves with custom parameters. + * ie. the coefficients can be arbitrary set through specially formatted keys, etc. + * As such, Prime.php is built very generically and it's not able to take full + * advantage of curves with 0 coefficients to produce simplified point doubling, + * point addition. Twisted Edwards curves, in contrast, do not have a way, currently, + * to customize them. As such, we can omit the super generic stuff from this class + * and let the named curves (Ed25519 and Ed448) define their own custom tailored + * point addition and point doubling methods. + * + * More info: + * + * https://en.wikipedia.org/wiki/Twisted_Edwards_curve + * + * PHP version 5 and 7 + * + * @author Jim Wigginton <[email protected]> + * @copyright 2017 Jim Wigginton + * @license http://www.opensource.org/licenses/mit-license.html MIT License + * @link http://pear.php.net/package/Math_BigInteger + */ + +namespace phpseclib3\Crypt\EC\BaseCurves; + +use phpseclib3\Math\BigInteger; +use phpseclib3\Math\PrimeField; +use phpseclib3\Math\PrimeField\Integer as PrimeInteger; + +/** + * Curves over a*x^2 + y^2 = 1 + d*x^2*y^2 + * + * @author Jim Wigginton <[email protected]> + */ +class TwistedEdwards extends Base +{ + /** + * The modulo + * + * @var BigInteger + */ + protected $modulo; + + /** + * Cofficient for x^2 + * + * @var object + */ + protected $a; + + /** + * Cofficient for x^2*y^2 + * + * @var object + */ + protected $d; + + /** + * Base Point + * + * @var object[] + */ + protected $p; + + /** + * The number zero over the specified finite field + * + * @var object + */ + protected $zero; + + /** + * The number one over the specified finite field + * + * @var object + */ + protected $one; + + /** + * The number two over the specified finite field + * + * @var object + */ + protected $two; + + /** + * Sets the modulo + */ + public function setModulo(BigInteger $modulo) + { + $this->modulo = $modulo; + $this->factory = new PrimeField($modulo); + $this->zero = $this->factory->newInteger(new BigInteger(0)); + $this->one = $this->factory->newInteger(new BigInteger(1)); + $this->two = $this->factory->newInteger(new BigInteger(2)); + } + + /** + * Set coefficients a and b + */ + public function setCoefficients(BigInteger $a, BigInteger $d) + { + if (!isset($this->factory)) { + throw new \RuntimeException('setModulo needs to be called before this method'); + } + $this->a = $this->factory->newInteger($a); + $this->d = $this->factory->newInteger($d); + } + + /** + * Set x and y coordinates for the base point + */ + public function setBasePoint($x, $y) + { + switch (true) { + case !$x instanceof BigInteger && !$x instanceof PrimeInteger: + throw new \UnexpectedValueException('Argument 1 passed to Prime::setBasePoint() must be an instance of either BigInteger or PrimeField\Integer'); + case !$y instanceof BigInteger && !$y instanceof PrimeInteger: + throw new \UnexpectedValueException('Argument 2 passed to Prime::setBasePoint() must be an instance of either BigInteger or PrimeField\Integer'); + } + if (!isset($this->factory)) { + throw new \RuntimeException('setModulo needs to be called before this method'); + } + $this->p = [ + $x instanceof BigInteger ? $this->factory->newInteger($x) : $x, + $y instanceof BigInteger ? $this->factory->newInteger($y) : $y + ]; + } + + /** + * Returns the a coefficient + * + * @return \phpseclib3\Math\PrimeField\Integer + */ + public function getA() + { + return $this->a; + } + + /** + * Returns the a coefficient + * + * @return \phpseclib3\Math\PrimeField\Integer + */ + public function getD() + { + return $this->d; + } + + /** + * Retrieve the base point as an array + * + * @return array + */ + public function getBasePoint() + { + if (!isset($this->factory)) { + throw new \RuntimeException('setModulo needs to be called before this method'); + } + /* + if (!isset($this->p)) { + throw new \RuntimeException('setBasePoint needs to be called before this method'); + } + */ + return $this->p; + } + + /** + * Returns the affine point + * + * @return \phpseclib3\Math\PrimeField\Integer[] + */ + public function convertToAffine(array $p) + { + if (!isset($p[2])) { + return $p; + } + list($x, $y, $z) = $p; + $z = $this->one->divide($z); + return [ + $x->multiply($z), + $y->multiply($z) + ]; + } + + /** + * Returns the modulo + * + * @return \phpseclib3\Math\BigInteger + */ + public function getModulo() + { + return $this->modulo; + } + + /** + * Tests whether or not the x / y values satisfy the equation + * + * @return boolean + */ + public function verifyPoint(array $p) + { + list($x, $y) = $p; + $x2 = $x->multiply($x); + $y2 = $y->multiply($y); + + $lhs = $this->a->multiply($x2)->add($y2); + $rhs = $this->d->multiply($x2)->multiply($y2)->add($this->one); + + return $lhs->equals($rhs); + } +} |