Curve::mul() - Code Metrics - Inspection of "PHP ECC Namespace changed" - Spomky-Labs/jose - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Push — v7 ( d5cb12...d36fb1 )

by Florent

created 2017-09-15 11:20 UTC

Curve::mul() B

↳ Parent: Curve

Complexity

Conditions	5
Paths	7

Size

Total Lines	40
Code Lines	21

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	40
rs	8.439
c	0
b	0
f	0
cc	5
eloc	21
nc	7
nop	2

<?php

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2017 Spomky-Labs
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

namespace Jose\Component\Core\Util\Ecc;

/**
 * This class is a representation of an EC over a field modulo a prime number.
 *
 * Important objectives for this class are:
 * - Does the curve contain a point?
 * - Comparison of two curves.
 */
final class Curve
{
    /**
     * Elliptic curve over the field of integers modulo a prime.
     *
     * @var \GMP
     */
    private $a;

    /**
     * @var \GMP
     */
    private $b;

    /**
     * @var \GMP
     */
    private $prime;

    /**
     * Binary length of keys associated with these curve parameters.
     *
     * @var int
     */
    private $size;

    /**
     * @var Point
     */
    private $generator;

    /**
     * @param int   $size
     * @param \GMP  $prime
     * @param \GMP  $a
     * @param \GMP  $b
     * @param Point $generator
     */
    public function __construct(int $size, \GMP $prime, \GMP $a, \GMP $b, Point $generator)
    {
        $this->size = $size;
        $this->prime = $prime;
        $this->a = $a;
        $this->b = $b;
        $this->generator = $generator;
    }

    /**
     * @return \GMP
     */
    public function getA(): \GMP
    {
        return $this->a;
    }

    /**
     * @return \GMP
     */
    public function getB(): \GMP
    {
        return $this->b;
    }

    /**
     * @return \GMP
     */
    public function getPrime(): \GMP
    {
        return $this->prime;
    }

    /**
     * @return int
     */
    public function getSize(): int
    {
        return $this->size;
    }

    /**
     * @param \GMP      $x
     * @param \GMP      $y
     * @param \GMP|null $order
     *
     * @return Point
     */
    public function getPoint(\GMP $x, \GMP $y, ?\GMP $order = null): Point
    {
        if (!$this->contains($x, $y)) {
            throw new \RuntimeException('Curve '.$this->__toString().' does not contain point ('.GmpMath::toString($x).', '.GmpMath::toString($y).')');
        }
        $point = Point::create($x, $y, $order);
        if (!is_null($order)) {
            $mul = $this->mul($point, $order);
            if (!$mul->isInfinity()) {
                throw new \RuntimeException('SELF * ORDER MUST EQUAL INFINITY. ('.(string) $mul.' found instead)');
            }
        }

        return $point;
    }

    /**
     * @param \GMP  $x
     * @param \GMP  $y
     *
     * @return PublicKey
     */
    public function getPublicKeyFrom(\GMP $x, \GMP $y): PublicKey
    {
        $point = $this->getPoint($x, $y);

        if (GmpMath::cmp($point->getX(), gmp_init(0, 10)) < 0 || GmpMath::cmp($this->generator->getOrder(), $point->getX()) <= 0
            || GmpMath::cmp($point->getY(), gmp_init(0, 10)) < 0 || GmpMath::cmp($this->generator->getOrder(), $point->getY()) <= 0
        ) {
            throw new \RuntimeException('Generator point has x and y out of range.');
        }


        return PublicKey::create($point);
    }

    /**
     * @param \GMP $x
     * @param \GMP $y
     *
     * @return bool
     */
    public function contains(\GMP $x, \GMP $y): bool
    {
        $eq_zero = GmpMath::equals(
            ModularArithmetic::sub(
                GmpMath::pow($y, 2),
                GmpMath::add(
                    GmpMath::add(
                        GmpMath::pow($x, 3),
                        GmpMath::mul($this->getA(), $x)
                    ),
                    $this->getB()
                ),
                $this->getPrime()
            ),
            gmp_init(0, 10)
        );

        return $eq_zero;
    }

    /**
     * @param Point $one
     * @param Point $two
     *
     * @return Point
     */
    public function add(Point $one, Point $two): Point
    {
        /*if (!$this->equals($two->getCurve())) {
            throw new \RuntimeException('The Elliptic Curves do not match.');
        }*/

        if ($two->isInfinity()) {
            return clone $one;
        }

        if ($one->isInfinity()) {
            return clone $two;
        }

        if (GmpMath::equals($two->getX(), $one->getX())) {
            if (GmpMath::equals($two->getY(), $one->getY())) {
                return $this->getDouble($one);
            } else {
                return Point::infinity();
            }
        }

        $slope = ModularArithmetic::div(
            GmpMath::sub($two->getY(), $one->getY()),
            GmpMath::sub($two->getX(), $one->getX()),
            $this->getPrime()
        );

        $xR = ModularArithmetic::sub(
            GmpMath::sub(GmpMath::pow($slope, 2), $one->getX()),
            $two->getX(),
            $this->getPrime()
        );

        $yR = ModularArithmetic::sub(
            GmpMath::mul($slope, GmpMath::sub($one->getX(), $xR)),
            $one->getY(),
            $this->getPrime()
        );

        return $this->getPoint($xR, $yR, $one->getOrder());
    }

    /**
     * @param Point $one
     * @param \GMP  $n
     *
     * @return Point
     */
    public function mul(Point $one, \GMP $n): Point
    {
        if ($one->isInfinity()) {
            return Point::infinity();
        }

        /** @var \GMP $zero */
        $zero = gmp_init(0, 10);
        if (GmpMath::cmp($one->getOrder(), $zero) > 0) {
            $n = GmpMath::mod($n, $one->getOrder());
        }

        if (GmpMath::equals($n, $zero)) {
            return Point::infinity();
        }

        /** @var Point[] $r */
        $r = [
            Point::infinity(),
            clone $one,
        ];

        $k = $this->getSize();
        $n = str_pad(GmpMath::baseConvert(GmpMath::toString($n), 10, 2), $k, '0', STR_PAD_LEFT);

        for ($i = 0; $i < $k; ++$i) {
            $j = $n[$i];

            Point::cswap($r[0], $r[1], $j ^ 1);

            $r[0] = $this->add($r[0],$r[1]);
            $r[1] = $this->getDouble($r[1]);

            Point::cswap($r[0], $r[1], $j ^ 1);
        }

        $this->validate($r[0]);

        return $r[0];
    }

    /**
     * @param Curve $other
     *
     * @return int
     */
    public function cmp(Curve $other): int
    {
        $equal = GmpMath::equals($this->getA(), $other->getA());
        $equal &= GmpMath::equals($this->getB(), $other->getB());
        $equal &= GmpMath::equals($this->getPrime(), $other->getPrime());

        return $equal ? 0 : 1;
    }

    /**
     * @param Curve $other
     *
     * @return bool
     */
    public function equals(Curve $other): bool
    {
        return $this->cmp($other) === 0;
    }

    /**
     * @return string
     */
    public function __toString(): string
    {
        return 'curve(' . GmpMath::toString($this->getA()) . ', ' . GmpMath::toString($this->getB()) . ', ' . GmpMath::toString($this->getPrime()) . ')';
    }

    /**
     * @param Point $point
     */
    private function validate(Point $point)
    {
        if (!$point->isInfinity() && !$this->contains($point->getX(), $point->getY())) {
            throw new \RuntimeException('Invalid point');
        }
    }

    /**
     * @param Point $point
     *
     * @return Point
     */
    public function getDouble(Point $point): Point
    {
        if ($point->isInfinity()) {
            return Point::infinity();
        }

        $a = $this->getA();
        $threeX2 = GmpMath::mul(gmp_init(3, 10), GmpMath::pow($point->getX(), 2));

        $tangent = ModularArithmetic::div(
            GmpMath::add($threeX2, $a),
            GmpMath::mul(gmp_init(2, 10), $point->getY()),
            $this->getPrime()
        );

        $x3 = ModularArithmetic::sub(
            GmpMath::pow($tangent, 2),
            GmpMath::mul(gmp_init(2, 10), $point->getX()),
            $this->getPrime()
        );

        $y3 = ModularArithmetic::sub(
            GmpMath::mul($tangent, GmpMath::sub($point->getX(), $x3)),
            $point->getY(),
            $this->getPrime()
        );

        return $this->getPoint($x3, $y3, $point->getOrder());
    }
}


1			<?php
2
3			/*
4			* The MIT License (MIT)
5			*
6			* Copyright (c) 2014-2017 Spomky-Labs
7			*
8			* This software may be modified and distributed under the terms
9			* of the MIT license. See the LICENSE file for details.
10			*/
11
12			namespace Jose\Component\Core\Util\Ecc;
13
14			/**
15			* This class is a representation of an EC over a field modulo a prime number.
16			*
17			* Important objectives for this class are:
18			* - Does the curve contain a point?
19			* - Comparison of two curves.
20			*/
21			final class Curve
22			{
23			/**
24			* Elliptic curve over the field of integers modulo a prime.
25			*
26			* @var \GMP
27			*/
28			private $a;
29
30			/**
31			* @var \GMP
32			*/
33			private $b;
34
35			/**
36			* @var \GMP
37			*/
38			private $prime;
39
40			/**
41			* Binary length of keys associated with these curve parameters.
42			*
43			* @var int
44			*/
45			private $size;
46
47			/**
48			* @var Point
49			*/
50			private $generator;
51
52			/**
53			* @param int $size
54			* @param \GMP $prime
55			* @param \GMP $a
56			* @param \GMP $b
57			* @param Point $generator
58			*/
59			public function __construct(int $size, \GMP $prime, \GMP $a, \GMP $b, Point $generator)
60			{
61			$this->size = $size;
62			$this->prime = $prime;
63			$this->a = $a;
64			$this->b = $b;
65			$this->generator = $generator;
66			}
67
68			/**
69			* @return \GMP
70			*/
71			public function getA(): \GMP
72			{
73			return $this->a;
74			}
75
76			/**
77			* @return \GMP
78			*/
79			public function getB(): \GMP
80			{
81			return $this->b;
82			}
83
84			/**
85			* @return \GMP
86			*/
87			public function getPrime(): \GMP
88			{
89			return $this->prime;
90			}
91
92			/**
93			* @return int
94			*/
95			public function getSize(): int
96			{
97			return $this->size;
98			}
99
100			/**
101			* @param \GMP $x
102			* @param \GMP $y
103			* @param \GMP\|null $order
104			*
105			* @return Point
106			*/
107			public function getPoint(\GMP $x, \GMP $y, ?\GMP $order = null): Point
108			{
109			if (!$this->contains($x, $y)) {
110			throw new \RuntimeException('Curve '.$this->__toString().' does not contain point ('.GmpMath::toString($x).', '.GmpMath::toString($y).')');
111			}
112			$point = Point::create($x, $y, $order);
113			if (!is_null($order)) {
114			$mul = $this->mul($point, $order);
115			if (!$mul->isInfinity()) {
116			throw new \RuntimeException('SELF * ORDER MUST EQUAL INFINITY. ('.(string) $mul.' found instead)');
117			}
118			}
119
120			return $point;
121			}
122
123			/**
124			* @param \GMP $x
125			* @param \GMP $y
126			*
127			* @return PublicKey
128			*/
129			public function getPublicKeyFrom(\GMP $x, \GMP $y): PublicKey
130			{
131			$point = $this->getPoint($x, $y);
132
133			if (GmpMath::cmp($point->getX(), gmp_init(0, 10)) < 0 \|\| GmpMath::cmp($this->generator->getOrder(), $point->getX()) <= 0
134			\|\| GmpMath::cmp($point->getY(), gmp_init(0, 10)) < 0 \|\| GmpMath::cmp($this->generator->getOrder(), $point->getY()) <= 0
135			) {
136			throw new \RuntimeException('Generator point has x and y out of range.');
137			}
138
139
140			return PublicKey::create($point);
141			}
142
143			/**
144			* @param \GMP $x
145			* @param \GMP $y
146			*
147			* @return bool
148			*/
149			public function contains(\GMP $x, \GMP $y): bool
150			{
151			$eq_zero = GmpMath::equals(
152			ModularArithmetic::sub(
153			GmpMath::pow($y, 2),
154			GmpMath::add(
155			GmpMath::add(
156			GmpMath::pow($x, 3),
157			GmpMath::mul($this->getA(), $x)
158			),
159			$this->getB()
160			),
161			$this->getPrime()
162			),
163			gmp_init(0, 10)
164			);
165
166			return $eq_zero;
167			}
168
169			/**
170			* @param Point $one
171			* @param Point $two
172			*
173			* @return Point
174			*/
175			public function add(Point $one, Point $two): Point
176			{
177			/*if (!$this->equals($two->getCurve())) {
178			throw new \RuntimeException('The Elliptic Curves do not match.');
179			}*/
180
181			if ($two->isInfinity()) {
182			return clone $one;
183			}
184
185			if ($one->isInfinity()) {
186			return clone $two;
187			}
188
189			if (GmpMath::equals($two->getX(), $one->getX())) {
190			if (GmpMath::equals($two->getY(), $one->getY())) {
191			return $this->getDouble($one);
192			} else {
193			return Point::infinity();
194			}
195			}
196
197			$slope = ModularArithmetic::div(
198			GmpMath::sub($two->getY(), $one->getY()),
199			GmpMath::sub($two->getX(), $one->getX()),
200			$this->getPrime()
201			);
202
203			$xR = ModularArithmetic::sub(
204			GmpMath::sub(GmpMath::pow($slope, 2), $one->getX()),
205			$two->getX(),
206			$this->getPrime()
207			);
208
209			$yR = ModularArithmetic::sub(
210			GmpMath::mul($slope, GmpMath::sub($one->getX(), $xR)),
211			$one->getY(),
212			$this->getPrime()
213			);
214
215			return $this->getPoint($xR, $yR, $one->getOrder());
216			}
217
218			/**
219			* @param Point $one
220			* @param \GMP $n
221			*
222			* @return Point
223			*/
224			public function mul(Point $one, \GMP $n): Point
225			{
226			if ($one->isInfinity()) {
227			return Point::infinity();
228			}
229
230			/** @var \GMP $zero */
231			$zero = gmp_init(0, 10);
232			if (GmpMath::cmp($one->getOrder(), $zero) > 0) {
233			$n = GmpMath::mod($n, $one->getOrder());
234			}
235
236			if (GmpMath::equals($n, $zero)) {
237			return Point::infinity();
238			}
239
240			/** @var Point[] $r */
241			$r = [
242			Point::infinity(),
243			clone $one,
244			];
245
246			$k = $this->getSize();
247			$n = str_pad(GmpMath::baseConvert(GmpMath::toString($n), 10, 2), $k, '0', STR_PAD_LEFT);
248
249			for ($i = 0; $i < $k; ++$i) {
250			$j = $n[$i];
251
252			Point::cswap($r[0], $r[1], $j ^ 1);
253
254			$r[0] = $this->add($r[0],$r[1]);
255			$r[1] = $this->getDouble($r[1]);
256
257			Point::cswap($r[0], $r[1], $j ^ 1);
258			}
259
260			$this->validate($r[0]);
261
262			return $r[0];
263			}
264
265			/**
266			* @param Curve $other
267			*
268			* @return int
269			*/
270			public function cmp(Curve $other): int
271			{
272			$equal = GmpMath::equals($this->getA(), $other->getA());
273			$equal &= GmpMath::equals($this->getB(), $other->getB());
274			$equal &= GmpMath::equals($this->getPrime(), $other->getPrime());
275
276			return $equal ? 0 : 1;
277			}
278
279			/**
280			* @param Curve $other
281			*
282			* @return bool
283			*/
284			public function equals(Curve $other): bool
285			{
286			return $this->cmp($other) === 0;
287			}
288
289			/**
290			* @return string
291			*/
292			public function __toString(): string
293			{
294			return 'curve(' . GmpMath::toString($this->getA()) . ', ' . GmpMath::toString($this->getB()) . ', ' . GmpMath::toString($this->getPrime()) . ')';
295			}
296
297			/**
298			* @param Point $point
299			*/
300			private function validate(Point $point)
301			{
302			if (!$point->isInfinity() && !$this->contains($point->getX(), $point->getY())) {
303			throw new \RuntimeException('Invalid point');
304			}
305			}
306
307			/**
308			* @param Point $point
309			*
310			* @return Point
311			*/
312			public function getDouble(Point $point): Point
313			{
314			if ($point->isInfinity()) {
315			return Point::infinity();
316			}
317
318			$a = $this->getA();
319			$threeX2 = GmpMath::mul(gmp_init(3, 10), GmpMath::pow($point->getX(), 2));
320
321			$tangent = ModularArithmetic::div(
322			GmpMath::add($threeX2, $a),
323			GmpMath::mul(gmp_init(2, 10), $point->getY()),
324			$this->getPrime()
325			);
326
327			$x3 = ModularArithmetic::sub(
328			GmpMath::pow($tangent, 2),
329			GmpMath::mul(gmp_init(2, 10), $point->getX()),
330			$this->getPrime()
331			);
332
333			$y3 = ModularArithmetic::sub(
334			GmpMath::mul($tangent, GmpMath::sub($point->getX(), $x3)),
335			$point->getY(),
336			$this->getPrime()
337			);
338
339			return $this->getPoint($x3, $y3, $point->getOrder());
340			}
341			}
342

Spomky-Labs / jose

Push — v7 ( d5cb12...d36fb1 )

Curve::mul() B

Complexity

Size

Duplication

Importance

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