NumberTheory::squareRootModP() - Code Metrics - Inspection of "Custom ECDH methods based on mdanter/phpecc" - Spomky-Labs/jose - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Push — v7 ( a687dc...e264c8 )

by Florent

created 2017-09-10 19:59 UTC

NumberTheory::squareRootModP() C

↳ Parent: NumberTheory

Complexity

Conditions	12
Paths	11

Size

Total Lines	93
Code Lines	56

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	93
rs	5.034
c	0
b	0
f	0
cc	12
eloc	56
nc	11
nop	2

How to fix Long Method Complexity

<?php

namespace Jose\Component\Core\Util\Ecc\Math;

/***********************************************************************
     * Copyright (C) 2012 Matyas Danter
     *
     * 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.
     ************************************************************************/

/**
 * Implementation of some number theoretic algorithms
 *
 * @author Matyas Danter
 */

/**
 * Rewritten to take a MathAdaptor to handle different environments. Has
 * some desireable functions for public key compression/recovery.
 */
final class NumberTheory
{
    /**
     * @var GmpMath
     */
    protected $adapter;

    /**
     * @param GmpMath $adapter
     */
    public function __construct(GmpMath $adapter)
    {
        $this->adapter = $adapter;
    }

    /**
     * @param \GMP[] $poly
     * @param $polymod
     * @param $p
     * @return array
     */
    public function polynomialReduceMod($poly, $polymod, $p): array
    {
        $adapter = $this->adapter;
        $count_polymod = count($polymod);
        if ($adapter->equals(end($polymod), gmp_init(1)) && $count_polymod > 1) {
            $zero = gmp_init(0);
            while (count($poly) >= $count_polymod) {
                if (!$adapter->equals(end($poly), $zero)) {
                    for ($i = 2; $i < $count_polymod + 1; $i++) {
                        $poly[count($poly) - $i] =
                            $adapter->mod(
                                $adapter->sub(
                                    $poly[count($poly) - $i],
                                    $adapter->mul(
                                        end($poly),
                                        $polymod[$count_polymod - $i]
                                    )
                                ),
                                $p
                            );
                    }
                }

                $poly = array_slice($poly, 0, count($poly) - 1);
            }

            return $poly;
        }

        throw new \InvalidArgumentException('Unable to calculate polynomialReduceMod');
    }

    /**
     * @param $m1
     * @param $m2
     * @param $polymod
     * @param $p
     * @return array
     */
    public function polynomialMultiplyMod($m1, $m2, $polymod, $p): array
    {
        $prod = array();
        $cm1 = count($m1);
        $cm2 = count($m2);
        $zero = gmp_init(0, 10);

        for ($i = 0; $i < $cm1; $i++) {
            for ($j = 0; $j < $cm2; $j++) {
                $index = $i + $j;
                if (!isset($prod[$index])) {
                    $prod[$index] = $zero;
                }
                $prod[$index] =
                    $this->adapter->mod(
                        $this->adapter->add(
                            $prod[$index],
                            $this->adapter->mul(
                                $m1[$i],
                                $m2[$j]
                            )
                        ),
                        $p
                    );
            }
        }

        return $this->polynomialReduceMod($prod, $polymod, $p);
    }

    /**
     * @param array $base
     * @param \GMP $exponent
     * @param array $polymod
     * @param \GMP $p
     * @return array|int
     */
    public function polynomialPowMod($base, \GMP $exponent, $polymod, \GMP $p)
    {
        $adapter = $this->adapter;
        $zero = gmp_init(0, 10);
        $one = gmp_init(1, 10);
        $two = gmp_init(2, 10);

        if ($adapter->cmp($exponent, $p) < 0) {
            if ($adapter->equals($exponent, $zero)) {
                return $one;
            }

            $G = $base;
            $k = $exponent;

            if ($adapter->equals($adapter->mod($k, $two), $one)) {
                $s = $G;
            } else {
                $s = array($one);
            }

            while ($adapter->cmp($k, $one) > 0) {
                $k = $adapter->div($k, $two);

                $G = $this->polynomialMultiplyMod($G, $G, $polymod, $p);
                if ($adapter->equals($adapter->mod($k, $two), $one)) {
                    $s = $this->polynomialMultiplyMod($G, $s, $polymod, $p);
                }
            }

            return $s;
        }

        throw new \InvalidArgumentException('Unable to calculate polynomialPowMod');

    }

    /**
     * @param \GMP $a
     * @param \GMP $p
     * @return \GMP
     */
    public function squareRootModP(\GMP $a, \GMP $p)
    {
        $math = $this->adapter;
        $zero = gmp_init(0, 10);
        $one = gmp_init(1, 10);
        $two = gmp_init(2, 10);
        $four = gmp_init(4, 10);
        $eight = gmp_init(8, 10);

        $modMath = $math->getModularArithmetic($p);
        if ($math->cmp($one, $p) < 0) {
            if ($math->equals($a, $zero)) {
                return $zero;
            }

            if ($math->equals($p, $two)) {
                return $a;
            }

            $jac = $math->jacobi($a, $p);
            if ($jac == -1) {
                throw new \LogicException($math->toString($a)." has no square root modulo ".$math->toString($p));
            }

            if ($math->equals($math->mod($p, $four), gmp_init(3, 10))) {
                return $modMath->pow($a, $math->div($math->add($p, $one), $four));
            }

            if ($math->equals($math->mod($p, $eight), gmp_init(5, 10))) {
                $d = $modMath->pow($a, $math->div($math->sub($p, $one), $four));
                if ($math->equals($d, $one)) {
                    return $modMath->pow($a, $math->div($math->add($p, gmp_init(3, 10)), $eight));
                }

                if ($math->equals($d, $math->sub($p, $one))) {
                    return $modMath->mul(
                        $math->mul(
                            $two,
                            $a
                        ),
                        $modMath->pow(
                            $math->mul(
                                $four,
                                $a
                            ),
                            $math->div(
                                $math->sub(
                                    $p,
                                    gmp_init(5, 10)
                                ),
                                $eight
                            )
                        )
                    );
                }
                //shouldn't get here
            }

            for ($b = gmp_init(2, 10); $math->cmp($b, $p) < 0; $b = gmp_add($b, gmp_init(1, 10))) {
/**
 * @return array|string
 */
function returnsDifferentValues($x) {
    if ($x) {
        return 'foo';
    }

    return array();
}

$x = returnsDifferentValues($y);
if (is_array($x)) {
    // $x is an array.
}
                if ($math->jacobi(
                    $math->sub(
                        $math->mul($b, $b),
/**
 * @return array|string
 */
function returnsDifferentValues($x) {
    if ($x) {
        return 'foo';
    }

    return array();
}

$x = returnsDifferentValues($y);
if (is_array($x)) {
    // $x is an array.
}
                        $math->mul($four, $a)
                    ),
                    $p
                ) == -1
                ) {
                    $f = array($a, $math->sub($zero, $b), $one);
/**
 * @return array|string
 */
function returnsDifferentValues($x) {
    if ($x) {
        return 'foo';
    }

    return array();
}

$x = returnsDifferentValues($y);
if (is_array($x)) {
    // $x is an array.
}

                    $ff = $this->polynomialPowMod(
                        array($zero, $one),
                        $math->div(
                            $math->add(
                                $p,
                                $one
                            ),
                            $two
                        ),
                        $f,
                        $p
                    );

                    if ($math->equals($ff[1], $zero)) {
                        return $ff[0];
                    }
                    // if we got here no b was found
                }
            }
        }

        throw new \InvalidArgumentException('Unable to calculate square root mod p!');

    }
}


1			<?php
2
3			namespace Jose\Component\Core\Util\Ecc\Math;
4
5			/***********************************************************************
6			* Copyright (C) 2012 Matyas Danter
7			*
8			* Permission is hereby granted, free of charge, to any person obtaining
9			* a copy of this software and associated documentation files (the "Software"),
10			* to deal in the Software without restriction, including without limitation
11			* the rights to use, copy, modify, merge, publish, distribute, sublicense,
12			* and/or sell copies of the Software, and to permit persons to whom the
13			* Software is furnished to do so, subject to the following conditions:
14			*
15			* The above copyright notice and this permission notice shall be included
16			* in all copies or substantial portions of the Software.
17			*
18			* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19			* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20			* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21			* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
22			* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23			* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24			* OTHER DEALINGS IN THE SOFTWARE.
25			************************************************************************/
26
27			/**
28			* Implementation of some number theoretic algorithms
29			*
30			* @author Matyas Danter
31			*/
32
33			/**
34			* Rewritten to take a MathAdaptor to handle different environments. Has
35			* some desireable functions for public key compression/recovery.
36			*/
37			final class NumberTheory
38			{
39			/**
40			* @var GmpMath
41			*/
42			protected $adapter;
43
44			/**
45			* @param GmpMath $adapter
46			*/
47			public function __construct(GmpMath $adapter)
48			{
49			$this->adapter = $adapter;
50			}
51
52			/**
53			* @param \GMP[] $poly
54			* @param $polymod
55			* @param $p
56			* @return array
57			*/
58			public function polynomialReduceMod($poly, $polymod, $p): array
59			{
60			$adapter = $this->adapter;
61			$count_polymod = count($polymod);
62			if ($adapter->equals(end($polymod), gmp_init(1)) && $count_polymod > 1) {
63			$zero = gmp_init(0);
64			while (count($poly) >= $count_polymod) {
65			if (!$adapter->equals(end($poly), $zero)) {
66			for ($i = 2; $i < $count_polymod + 1; $i++) {
67			$poly[count($poly) - $i] =
68			$adapter->mod(
69			$adapter->sub(
70			$poly[count($poly) - $i],
71			$adapter->mul(
72			end($poly),
73			$polymod[$count_polymod - $i]
74			)
75			),
76			$p
77			);
78			}
79			}
80
81			$poly = array_slice($poly, 0, count($poly) - 1);
82			}
83
84			return $poly;
85			}
86
87			throw new \InvalidArgumentException('Unable to calculate polynomialReduceMod');
88			}
89
90			/**
91			* @param $m1
92			* @param $m2
93			* @param $polymod
94			* @param $p
95			* @return array
96			*/
97			public function polynomialMultiplyMod($m1, $m2, $polymod, $p): array
98			{
99			$prod = array();
100			$cm1 = count($m1);
101			$cm2 = count($m2);
102			$zero = gmp_init(0, 10);
103
104			for ($i = 0; $i < $cm1; $i++) {
105			for ($j = 0; $j < $cm2; $j++) {
106			$index = $i + $j;
107			if (!isset($prod[$index])) {
108			$prod[$index] = $zero;
109			}
110			$prod[$index] =
111			$this->adapter->mod(
112			$this->adapter->add(
113			$prod[$index],
114			$this->adapter->mul(
115			$m1[$i],
116			$m2[$j]
117			)
118			),
119			$p
120			);
121			}
122			}
123
124			return $this->polynomialReduceMod($prod, $polymod, $p);
125			}
126
127			/**
128			* @param array $base
129			* @param \GMP $exponent
130			* @param array $polymod
131			* @param \GMP $p
132			* @return array\|int
133			*/
134			public function polynomialPowMod($base, \GMP $exponent, $polymod, \GMP $p)
135			{
136			$adapter = $this->adapter;
137			$zero = gmp_init(0, 10);
138			$one = gmp_init(1, 10);
139			$two = gmp_init(2, 10);
140
141			if ($adapter->cmp($exponent, $p) < 0) {
142			if ($adapter->equals($exponent, $zero)) {
143			return $one;
144			}
145
146			$G = $base;
147			$k = $exponent;
148
149			if ($adapter->equals($adapter->mod($k, $two), $one)) {
150			$s = $G;
151			} else {
152			$s = array($one);
153			}
154
155			while ($adapter->cmp($k, $one) > 0) {
156			$k = $adapter->div($k, $two);
157
158			$G = $this->polynomialMultiplyMod($G, $G, $polymod, $p);
159			if ($adapter->equals($adapter->mod($k, $two), $one)) {
160			$s = $this->polynomialMultiplyMod($G, $s, $polymod, $p);
161			}
162			}
163
164			return $s;
165			}
166
167			throw new \InvalidArgumentException('Unable to calculate polynomialPowMod');
168
169			}
170
171			/**
172			* @param \GMP $a
173			* @param \GMP $p
174			* @return \GMP
175			*/
176			public function squareRootModP(\GMP $a, \GMP $p)
177			{
178			$math = $this->adapter;
179			$zero = gmp_init(0, 10);
180			$one = gmp_init(1, 10);
181			$two = gmp_init(2, 10);
182			$four = gmp_init(4, 10);
183			$eight = gmp_init(8, 10);
184
185			$modMath = $math->getModularArithmetic($p);
186			if ($math->cmp($one, $p) < 0) {
187			if ($math->equals($a, $zero)) {
188			return $zero;
189			}
190
191			if ($math->equals($p, $two)) {
192			return $a;
193			}
194
195			$jac = $math->jacobi($a, $p);
196			if ($jac == -1) {
197			throw new \LogicException($math->toString($a)." has no square root modulo ".$math->toString($p));
198			}
199
200			if ($math->equals($math->mod($p, $four), gmp_init(3, 10))) {
201			return $modMath->pow($a, $math->div($math->add($p, $one), $four));
202			}
203
204			if ($math->equals($math->mod($p, $eight), gmp_init(5, 10))) {
205			$d = $modMath->pow($a, $math->div($math->sub($p, $one), $four));
206			if ($math->equals($d, $one)) {
207			return $modMath->pow($a, $math->div($math->add($p, gmp_init(3, 10)), $eight));
208			}
209
210			if ($math->equals($d, $math->sub($p, $one))) {
211			return $modMath->mul(
212			$math->mul(
213			$two,
214			$a
215			),
216			$modMath->pow(
217			$math->mul(
218			$four,
219			$a
220			),
221			$math->div(
222			$math->sub(
223			$p,
224			gmp_init(5, 10)
225			),
226			$eight
227			)
228			)
229			);
230			}
231			//shouldn't get here
232			}
233
234			for ($b = gmp_init(2, 10); $math->cmp($b, $p) < 0; $b = gmp_add($b, gmp_init(1, 10))) {
			1 ignored issue – show Bug introduced 2017-09-10 20:02 UTC by Report Bug Copy Issue Report It seems like `$b` defined by `gmp_add($b, gmp_init(1, 10))` on line `234` can also be of type `resource`; however, `Jose\Component\Core\Util\Ecc\Math\GmpMath::cmp()` does only seem to accept `object<GMP>`, maybe add an additional type check? If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check: /** * @return array\|string */ function returnsDifferentValues($x) { if ($x) { return 'foo'; } return array(); } $x = returnsDifferentValues($y); if (is_array($x)) { // $x is an array. } If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue. Loading history... Performance Best Practice introduced 2017-09-10 20:02 UTC by Report Bug Copy Issue Report Consider avoiding function calls on each iteration of the `for` loop. If you have a function call in the test part of a `for` loop, this function is executed on each iteration. Often such a function, can be moved to the initialization part and be cached. // count() is called on each iteration for ($i=0; $i < count($collection); $i++) { } // count() is only called once for ($i=0, $c=count($collection); $i<$c; $i++) { } Loading history...
235			if ($math->jacobi(
236			$math->sub(
237			$math->mul($b, $b),
			1 ignored issue – show Bug introduced 2017-09-10 20:02 UTC by Report Bug Copy Issue Report It seems like `$b` defined by `gmp_add($b, gmp_init(1, 10))` on line `234` can also be of type `resource`; however, `Jose\Component\Core\Util\Ecc\Math\GmpMath::mul()` does only seem to accept `object<GMP>`, maybe add an additional type check? If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check: /** * @return array\|string */ function returnsDifferentValues($x) { if ($x) { return 'foo'; } return array(); } $x = returnsDifferentValues($y); if (is_array($x)) { // $x is an array. } If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue. Loading history...
238			$math->mul($four, $a)
239			),
240			$p
241			) == -1
242			) {
243			$f = array($a, $math->sub($zero, $b), $one);
			1 ignored issue – show Bug introduced 2017-09-10 20:02 UTC by Report Bug Copy Issue Report It seems like `$b` defined by `gmp_add($b, gmp_init(1, 10))` on line `234` can also be of type `resource`; however, `Jose\Component\Core\Util\Ecc\Math\GmpMath::sub()` does only seem to accept `object<GMP>`, maybe add an additional type check? If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check: /** * @return array\|string */ function returnsDifferentValues($x) { if ($x) { return 'foo'; } return array(); } $x = returnsDifferentValues($y); if (is_array($x)) { // $x is an array. } If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue. Loading history...
244
245			$ff = $this->polynomialPowMod(
246			array($zero, $one),
247			$math->div(
248			$math->add(
249			$p,
250			$one
251			),
252			$two
253			),
254			$f,
255			$p
256			);
257
258			if ($math->equals($ff[1], $zero)) {
259			return $ff[0];
260			}
261			// if we got here no b was found
262			}
263			}
264			}
265
266			throw new \InvalidArgumentException('Unable to calculate square root mod p!');
267
268			}
269			}
270

Spomky-Labs / jose

Push — v7 ( a687dc...e264c8 )

NumberTheory::squareRootModP() C

Complexity

Size

Duplication

Importance

How to fix Long Method Complexity

Long Method

Duplication Side-by-Side

Filter issues like