Completed
Pull Request — master (#359)
by Ruben de
14:27
created

EcAdapter::verify()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 6
Code Lines 2

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 2
CRAP Score 1

Importance

Changes 1
Bugs 0 Features 0
Metric Value
c 1
b 0
f 0
dl 0
loc 6
ccs 2
cts 2
cp 1
rs 9.4285
cc 1
eloc 2
nc 1
nop 3
crap 1
1
<?php
2
3
namespace BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Adapter;
4
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use BitWasp\Bitcoin\Crypto\EcAdapter\Adapter\EcAdapterInterface;
6
use BitWasp\Bitcoin\Crypto\EcAdapter\Signature\CompactSignatureInterface;
7
use BitWasp\Bitcoin\Crypto\EcAdapter\Signature\SignatureInterface;
8
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PublicKey;
9
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Signature\Signature;
10
use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface;
11
use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PrivateKeyInterface;
12
use BitWasp\Bitcoin\Crypto\Random\RbgInterface;
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use BitWasp\Bitcoin\Crypto\Random\Rfc6979;
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use BitWasp\Bitcoin\Math\Math;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PrivateKey;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Signature\CompactSignature;
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use BitWasp\Buffertools\BufferInterface;
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use Mdanter\Ecc\Crypto\Signature\Signer;
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use Mdanter\Ecc\Primitives\GeneratorPoint;
20
use Mdanter\Ecc\Primitives\PointInterface;
21
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class EcAdapter implements EcAdapterInterface
23
{
24
    /**
25
     * @var Math
26
     */
27
    private $math;
28
29
    /**
30
     * @var GeneratorPoint
31
     */
32
    private $generator;
33
34
    /**
35
     * @param Math $math
36
     * @param GeneratorPoint $generator
37
     */
38 14
    public function __construct(Math $math, GeneratorPoint $generator)
39
    {
40 14
        $this->math = $math;
41 14
        $this->generator = $generator;
42 14
    }
43
44
    /**
45
     * @return Math
46
     */
47 195
    public function getMath()
48
    {
49 195
        return $this->math;
50
    }
51
52
    /**
53
     * @return GeneratorPoint
54
     */
55 145
    public function getGenerator()
56
    {
57 145
        return $this->generator;
58
    }
59
60
    /**
61
     * @param \GMP $scalar
62
     * @param bool|false $compressed
63
     * @return PrivateKey
64
     */
65 64
    public function getPrivateKey(\GMP $scalar, $compressed = false)
66
    {
67 64
        return new PrivateKey($this, $scalar, $compressed);
68
    }
69
70
    /**
71
     * @param PointInterface $point
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     * @param bool|false $compressed
73
     * @return PublicKey
74
     */
75 54
    public function getPublicKey(PointInterface $point, $compressed = false)
76
    {
77 54
        return new PublicKey($this, $point, $compressed);
78
    }
79
80
    /**
81
     * @param \GMP $r
82
     * @param \GMP $s
83
     * @return Signature
84
     */
85
    public function getSignature(\GMP $r, \GMP $s)
86
    {
87
        return new Signature($this, $r, $s);
88
    }
89
90
    /**
91
     * @param BufferInterface $messageHash
92
     * @param PublicKey $publicKey
93
     * @param Signature $signature
94
     * @return bool
95
     */
96 83
    private function doVerify(BufferInterface $messageHash, PublicKey $publicKey, Signature $signature)
97
    {
98 83
        $hash = gmp_init($messageHash->getHex(), 16);
99 83
        $signer = new Signer($this->math);
100 83
        return $signer->verify($publicKey, $signature, $hash);
101
    }
102
103
    /**
104
     * @param BufferInterface $messageHash
105
     * @param PublicKeyInterface $publicKey
106
     * @param SignatureInterface $signature
107
     * @return bool
108
     */
109 83
    public function verify(BufferInterface $messageHash, PublicKeyInterface $publicKey, SignatureInterface $signature)
110
    {
111
        /** @var PublicKey $publicKey */
112
        /** @var Signature $signature */
113 83
        return $this->doVerify($messageHash, $publicKey, $signature);
0 ignored issues
show
Compatibility introduced by
$publicKey of type object<BitWasp\Bitcoin\C...Key\PublicKeyInterface> is not a sub-type of object<BitWasp\Bitcoin\C...l\PhpEcc\Key\PublicKey>. It seems like you assume a concrete implementation of the interface BitWasp\Bitcoin\Crypto\E...\Key\PublicKeyInterface to be always present.

This check looks for parameters that are defined as one type in their type hint or doc comment but seem to be used as a narrower type, i.e an implementation of an interface or a subclass.

Consider changing the type of the parameter or doing an instanceof check before assuming your parameter is of the expected type.

Loading history...
114
    }
115
116
    /**
117
     * @param BufferInterface $messageHash
118
     * @param PrivateKey $privateKey
119
     * @param RbgInterface|null $rbg
120
     * @return Signature
121
     */
122 23
    private function doSign(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
123
    {
124 23
        $rbg = $rbg ?: new Rfc6979($this, $privateKey, $messageHash);
125 23
        $randomK = gmp_init($rbg->bytes(32)->getHex(), 16);
126 23
        $hash = gmp_init($messageHash->getHex(), 16);
127
128 23
        $signer = new Signer($this->math);
129 23
        $signature = $signer->sign($privateKey, $hash, $randomK);
130 23
        $s = $signature->getS();
131
132
        // if s is less than half the curve order, invert s
133 23
        if (!$this->validateSignatureElement($s, true)) {
134 12
            $s = $this->math->sub($this->generator->getOrder(), $s);
135
        }
136
137 23
        return new Signature($this, $signature->getR(), $s);
0 ignored issues
show
Bug introduced by
It seems like $s defined by $this->math->sub($this->...erator->getOrder(), $s) on line 134 can also be of type resource; however, BitWasp\Bitcoin\Crypto\E...ignature::__construct() 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...
138
    }
139
140
    /**
141
     * @param BufferInterface $messageHash
142
     * @param PrivateKeyInterface $privateKey
143
     * @param RbgInterface $rbg
144
     * @return SignatureInterface
145
     * @throws \BitWasp\Bitcoin\Exceptions\RandomBytesFailure
146
     */
147 23
    public function sign(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
148
    {
149
        /** @var PrivateKey $privateKey */
150 23
        return $this->doSign($messageHash, $privateKey, $rbg);
151
    }
152
153
    /**
154
     * @param BufferInterface $messageHash
155
     * @param CompactSignatureInterface $signature
156
     * @return PublicKey
157
     * @throws \Exception
158
     */
159 10
    public function recover(BufferInterface $messageHash, CompactSignatureInterface $signature)
160
    {
161 10
        $math = $this->getMath();
162 10
        $G = $this->getGenerator();
163
164 10
        $zero = gmp_init(0);
165 10
        $one = gmp_init(1);
166
167 10
        $r = $signature->getR();
168 10
        $s = $signature->getS();
169 10
        $recGMP = gmp_init($signature->getRecoveryId(), 10);
170 10
        $isYEven = $math->cmp($math->bitwiseAnd($recGMP, $one), $zero) !== 0;
171 10
        $isSecondKey = $math->cmp($math->bitwiseAnd($recGMP, gmp_init(2)), $zero) !== 0;
172 10
        $curve = $G->getCurve();
173
174
        // Precalculate (p + 1) / 4 where p is the field order
175 10
        $p_over_four = $math->div($math->add($curve->getPrime(), $one), gmp_init(4));
176
177
        // 1.1 Compute x
178 10
        if (!$isSecondKey) {
179 10
            $x = $r;
180 1
        } else {
181 3
            $x = $math->add($r, $G->getOrder());
182
        }
183
184
        // 1.3 Convert x to point
185 10
        $alpha = $math->mod($math->add($math->add($math->pow($x, 3), $math->mul($curve->getA(), $x)), $curve->getB()), $curve->getPrime());
0 ignored issues
show
Bug introduced by
It seems like $x defined by $math->add($r, $G->getOrder()) on line 181 can also be of type resource; however, Mdanter\Ecc\Math\GmpMath::pow() 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...
Bug introduced by
It seems like $x defined by $math->add($r, $G->getOrder()) on line 181 can also be of type resource; however, Mdanter\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...
186 10
        $beta = $math->powmod($alpha, $p_over_four, $curve->getPrime());
187
188
        // If beta is even, but y isn't or vice versa, then convert it,
189
        // otherwise we're done and y == beta.
190 10
        if ($math->isEven($beta) === $isYEven) {
191 9
            $y = $math->sub($curve->getPrime(), $beta);
192 1
        } else {
193 4
            $y = $beta;
194
        }
195
196
        // 1.4 Check that nR is at infinity (implicitly done in constructor)
197 10
        $R = $G->getCurve()->getPoint($x, $y);
0 ignored issues
show
Bug introduced by
It seems like $x defined by $math->add($r, $G->getOrder()) on line 181 can also be of type resource; however, Mdanter\Ecc\Primitives\C...FpInterface::getPoint() 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...
198
199 10
        $point_negate = function (PointInterface $p) use ($math, $G) {
200 10
            return $G->getCurve()->getPoint($p->getX(), $math->mul($p->getY(), gmp_init('-1', 10)));
201 10
        };
202
203
        // 1.6.1 Compute a candidate public key Q = r^-1 (sR - eG)
204 10
        $rInv = $math->inverseMod($r, $G->getOrder());
205 10
        $eGNeg = $point_negate($G->mul($messageHash->getGmp()));
206 10
        $Q = $R->mul($s)->add($eGNeg)->mul($rInv);
207
208
        // 1.6.2 Test Q as a public key
209 10
        $Qk = new PublicKey($this, $Q, $signature->isCompressed());
210 10
        if ($this->verify($messageHash, $Qk, $signature->convert())) {
211 7
            return $Qk;
212
        }
213
214 3
        throw new \Exception('Unable to recover public key');
215
    }
216
217
    /**
218
     * Attempt to calculate the public key recovery param by trial and error
219
     *
220
     * @param \GMP $r
221
     * @param \GMP $s
222
     * @param BufferInterface $messageHash
223
     * @param PublicKey $publicKey
224
     * @return int
225
     * @throws \Exception
226
     */
227 9
    public function calcPubKeyRecoveryParam(\GMP $r, \GMP $s, BufferInterface $messageHash, PublicKey $publicKey)
228
    {
229 9
        $Q = $publicKey->getPoint();
230 9
        for ($i = 0; $i < 4; $i++) {
231
            try {
232 9
                $recover = $this->recover($messageHash, new CompactSignature($this, $r, $s, $i, $publicKey->isCompressed()));
233 6
                if ($Q->equals($recover->getPoint())) {
234 6
                    return $i;
235
                }
236 3
            } catch (\Exception $e) {
237 3
                continue;
238
            }
239
        }
240
241 3
        throw new \Exception('Failed to find valid recovery factor');
242
    }
243
244
    /**
245
     * @param BufferInterface $messageHash
246
     * @param PrivateKey $privateKey
247
     * @param RbgInterface|null $rbg
248
     * @return CompactSignature
249
     * @throws \Exception
250
     */
251 6
    private function doSignCompact(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
252
    {
253 6
        $sign = $this->sign($messageHash, $privateKey, $rbg);
254
255
        // calculate the recovery param
256
        // there should be a way to get this when signing too, but idk how ...
257 6
        return new CompactSignature(
258
            $this,
259 6
            $sign->getR(),
260 6
            $sign->getS(),
261 6
            $this->calcPubKeyRecoveryParam($sign->getR(), $sign->getS(), $messageHash, $privateKey->getPublicKey()),
262 6
            $privateKey->isCompressed()
263
        );
264
    }
265
266
    /**
267
     * @param PrivateKeyInterface $privateKey
268
     * @param BufferInterface $messageHash
269
     * @param RbgInterface $rbg
270
     * @return CompactSignature
271
     */
272 6
    public function signCompact(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
273
    {
274
        /** @var PrivateKey $privateKey */
275 6
        return $this->doSignCompact($messageHash, $privateKey, $rbg);
276
    }
277
278
    /**
279
     * @param BufferInterface $privateKey
280
     * @return bool
281
     */
282 66
    public function validatePrivateKey(BufferInterface $privateKey)
283
    {
284 66
        $math = $this->math;
285 66
        $scalar = $privateKey->getGmp();
286 66
        return $math->cmp($scalar, gmp_init(0)) > 0 && $math->cmp($scalar, $this->getGenerator()->getOrder()) < 0;
287
    }
288
289
    /**
290
     * @param \GMP $element
291
     * @param bool $half
292
     * @return bool
293
     */
294 26
    public function validateSignatureElement(\GMP $element, $half = false)
295
    {
296 26
        $math = $this->getMath();
297 26
        $against = $this->getGenerator()->getOrder();
298 26
        if ($half) {
299 26
            $against = $math->rightShift($against, 1);
300
        }
301
302 26
        return $math->cmp($element, $against) < 0 && $math->cmp($element, gmp_init(0)) !== 0;
303
    }
304
305
    /**
306
     * @param BufferInterface $publicKey
307
     * @return PublicKeyInterface
308
     * @throws \Exception
309
     */
310 137
    public function publicKeyFromBuffer(BufferInterface $publicKey)
311
    {
312 137
        $prefix = $publicKey->slice(0, 1)->getBinary();
313 137
        $size = $publicKey->getSize();
314 137
        $compressed = false;
315 137
        if ($prefix == PublicKey::KEY_UNCOMPRESSED || $prefix === "\x06" || $prefix === "\x07") {
316 58
            if ($size !== PublicKey::LENGTH_UNCOMPRESSED) {
317 58
                throw new \Exception('Invalid length for uncompressed key');
318
            }
319 80
        } else if ($prefix === PublicKey::KEY_COMPRESSED_EVEN || $prefix === PublicKey::KEY_COMPRESSED_ODD) {
320 79
            if ($size !== PublicKey::LENGTH_COMPRESSED) {
321
                throw new \Exception('Invalid length for compressed key');
322
            }
323 79
            $compressed = true;
324
        } else {
325 1
            throw new \Exception('Unknown public key prefix');
326
        }
327
        
328 135
        $x = $publicKey->slice(1, 32)->getGmp();
329 135
        $curve = $this->generator->getCurve();
330 135
        $y = $compressed
331 79
            ? $curve->recoverYfromX($prefix === PublicKey::KEY_COMPRESSED_ODD, $x)
332 135
            : $publicKey->slice(33, 32)->getGmp();
333
334 135
        return new PublicKey(
335
            $this,
336 135
            $curve->getPoint($x, $y),
337
            $compressed,
338
            $prefix
339
        );
340
    }
341
}
342