Completed
Pull Request — master (#371)
by Ruben de
73:41 queued 69:36
created

EcAdapter::doSign()   A

Complexity

Conditions 3
Paths 4

Size

Total Lines 17
Code Lines 10

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 11
CRAP Score 3

Importance

Changes 1
Bugs 0 Features 0
Metric Value
cc 3
eloc 10
c 1
b 0
f 0
nc 4
nop 3
dl 0
loc 17
ccs 11
cts 11
cp 1
crap 3
rs 9.4285
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;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PublicKey;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Signature\Signature;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface;
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use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PrivateKeyInterface;
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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;
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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 38
    public function __construct(Math $math, GeneratorPoint $generator)
39
    {
40 38
        $this->math = $math;
41 38
        $this->generator = $generator;
42 38
    }
43
44
    /**
45
     * @return Math
46
     */
47 748
    public function getMath()
48
    {
49 748
        return $this->math;
50
    }
51
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    /**
53
     * @return GeneratorPoint
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     */
55 534
    public function getGenerator()
56
    {
57 534
        return $this->generator;
58
    }
59
60
    /**
61
     * @param \GMP $scalar
62
     * @param bool|false $compressed
63
     * @return PrivateKey
64
     */
65 202
    public function getPrivateKey(\GMP $scalar, $compressed = false)
66
    {
67 202
        return new PrivateKey($this, $scalar, $compressed);
68
    }
69
70
    /**
71
     * @param PointInterface $point
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     * @param bool|false $compressed
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     * @return PublicKey
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     */
75 170
    public function getPublicKey(PointInterface $point, $compressed = false)
76
    {
77 170
        return new PublicKey($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);
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    }
89
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    /**
91
     * @param BufferInterface $messageHash
92
     * @param PublicKey $publicKey
93
     * @param Signature $signature
94
     * @return bool
95
     */
96 308
    private function doVerify(BufferInterface $messageHash, PublicKey $publicKey, Signature $signature)
97
    {
98 308
        $hash = gmp_init($messageHash->getHex(), 16);
99 308
        $signer = new Signer($this->math);
100 308
        return $signer->verify($publicKey, $signature, $hash);
101
    }
102
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    /**
104
     * @param BufferInterface $messageHash
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     * @param PublicKeyInterface $publicKey
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     * @param SignatureInterface $signature
107
     * @return bool
108
     */
109 308
    public function verify(BufferInterface $messageHash, PublicKeyInterface $publicKey, SignatureInterface $signature)
110
    {
111
        /** @var PublicKey $publicKey */
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        /** @var Signature $signature */
113 308
        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.

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114
    }
115
116
    /**
117
     * @param BufferInterface $messageHash
118
     * @param PrivateKey $privateKey
119
     * @param RbgInterface|null $rbg
120
     * @return Signature
121
     */
122 92
    private function doSign(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
123
    {
124 92
        $rbg = $rbg ?: new Rfc6979($this, $privateKey, $messageHash);
125 92
        $randomK = gmp_init($rbg->bytes(32)->getHex(), 16);
126 92
        $hash = gmp_init($messageHash->getHex(), 16);
127
128 92
        $signer = new Signer($this->math);
129 92
        $signature = $signer->sign($privateKey, $hash, $randomK);
130 92
        $s = $signature->getS();
131
132
        // if s is less than half the curve order, invert s
133 92
        if (!$this->validateSignatureElement($s, true)) {
134 46
            $s = $this->math->sub($this->generator->getOrder(), $s);
135 21
        }
136
137 92
        return new Signature($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 92
    public function sign(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
148
    {
149
        /** @var PrivateKey $privateKey */
150 92
        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 34
    public function recover(BufferInterface $messageHash, CompactSignatureInterface $signature)
160
    {
161 34
        $math = $this->getMath();
162 34
        $G = $this->getGenerator();
163
164 34
        $zero = gmp_init(0);
165 34
        $one = gmp_init(1);
166
167 34
        $r = $signature->getR();
168 34
        $s = $signature->getS();
169 34
        $recGMP = gmp_init($signature->getRecoveryId(), 10);
170 34
        $isYEven = $math->cmp($math->bitwiseAnd($recGMP, $one), $zero) !== 0;
171 34
        $isSecondKey = $math->cmp($math->bitwiseAnd($recGMP, gmp_init(2)), $zero) !== 0;
172 34
        $curve = $G->getCurve();
173
174
        // Precalculate (p + 1) / 4 where p is the field order
175 34
        $p_over_four = $math->div($math->add($curve->getPrime(), $one), gmp_init(4));
176
177
        // 1.1 Compute x
178 34
        if (!$isSecondKey) {
179 34
            $x = $r;
180 16
        } else {
181 6
            $x = $math->add($r, $G->getOrder());
182
        }
183
184
        // 1.3 Convert x to point
185 34
        $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 34
        $beta = $math->powmod($alpha, $p_over_four, $curve->getPrime());
187
188
        // If beta is even, but y isn't or vice versa, then convert it,
189
        // otherwise we're done and y == beta.
190 34
        if ($math->isEven($beta) === $isYEven) {
191 24
            $y = $math->sub($curve->getPrime(), $beta);
192 10
        } else {
193 22
            $y = $beta;
194
        }
195
196
        // 1.4 Check that nR is at infinity (implicitly done in constructor)
197 34
        $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 34
        $point_negate = function (PointInterface $p) use ($math, $G) {
200 34
            return $G->getCurve()->getPoint($p->getX(), $math->mul($p->getY(), gmp_init('-1', 10)));
201 34
        };
202
203
        // 1.6.1 Compute a candidate public key Q = r^-1 (sR - eG)
204 34
        $rInv = $math->inverseMod($r, $G->getOrder());
205 34
        $eGNeg = $point_negate($G->mul($messageHash->getGmp()));
206 34
        $Q = $R->mul($s)->add($eGNeg)->mul($rInv);
207
208
        // 1.6.2 Test Q as a public key
209 34
        $Qk = new PublicKey($this, $Q, $signature->isCompressed());
210 34
        if ($this->verify($messageHash, $Qk, $signature->convert())) {
211 28
            return $Qk;
212
        }
213
214 6
        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 30
    public function calcPubKeyRecoveryParam(\GMP $r, \GMP $s, BufferInterface $messageHash, PublicKey $publicKey)
228
    {
229 30
        $Q = $publicKey->getPoint();
230 30
        for ($i = 0; $i < 4; $i++) {
231
            try {
232 30
                $recover = $this->recover($messageHash, new CompactSignature($this, $r, $s, $i, $publicKey->isCompressed()));
233 24
                if ($Q->equals($recover->getPoint())) {
234 24
                    return $i;
235
                }
236 6
            } catch (\Exception $e) {
237 6
                continue;
238
            }
239
        }
240
241 6
        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 24
    private function doSignCompact(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
252
    {
253 24
        $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 24
        return new CompactSignature(
258 12
            $this,
259 24
            $sign->getR(),
260 24
            $sign->getS(),
261 24
            $this->calcPubKeyRecoveryParam($sign->getR(), $sign->getS(), $messageHash, $privateKey->getPublicKey()),
262 24
            $privateKey->isCompressed()
263 12
        );
264
    }
265
266
    /**
267
     * @param PrivateKeyInterface $privateKey
268
     * @param BufferInterface $messageHash
269
     * @param RbgInterface $rbg
270
     * @return CompactSignature
271
     */
272 24
    public function signCompact(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
273
    {
274
        /** @var PrivateKey $privateKey */
275 24
        return $this->doSignCompact($messageHash, $privateKey, $rbg);
276
    }
277
278
    /**
279
     * @param BufferInterface $privateKey
280
     * @return bool
281
     */
282 210
    public function validatePrivateKey(BufferInterface $privateKey)
283
    {
284 210
        $math = $this->math;
285 210
        $scalar = $privateKey->getGmp();
286 210
        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
     */
294 104
    public function validateSignatureElement(\GMP $element, $half = false)
295
    {
296 104
        $math = $this->getMath();
297 104
        $against = $this->getGenerator()->getOrder();
298 104
        if ($half) {
299 104
            $against = $math->rightShift($against, 1);
300 52
        }
301
302 104
        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
     */
310 544
    public function publicKeyFromBuffer(BufferInterface $publicKey)
311
    {
312 544
        $prefix = $publicKey->slice(0, 1)->getBinary();
313 544
        $size = $publicKey->getSize();
314 544
        $compressed = false;
315 544
        if ($prefix == PublicKey::KEY_UNCOMPRESSED || $prefix === "\x06" || $prefix === "\x07") {
316 268
            if ($size !== PublicKey::LENGTH_UNCOMPRESSED) {
317 136
                throw new \Exception('Invalid length for uncompressed key');
318
            }
319 422
        } else if ($prefix === PublicKey::KEY_COMPRESSED_EVEN || $prefix === PublicKey::KEY_COMPRESSED_ODD) {
320 300
            if ($size !== PublicKey::LENGTH_COMPRESSED) {
321
                throw new \Exception('Invalid length for compressed key');
322
            }
323 300
            $compressed = true;
324 150
        } else {
325 4
            throw new \Exception('Unknown public key prefix');
326
        }
327
        
328 536
        $x = $publicKey->slice(1, 32)->getGmp();
329 536
        $curve = $this->generator->getCurve();
330 268
        $y = $compressed
331 418
            ? $curve->recoverYfromX($prefix === PublicKey::KEY_COMPRESSED_ODD, $x)
332 536
            : $publicKey->slice(33, 32)->getGmp();
333
334 536
        return new PublicKey(
335 268
            $this,
336 536
            $curve->getPoint($x, $y),
337 268
            $compressed,
338
            $prefix
339 268
        );
340
    }
341
}
342