Completed
Pull Request — master (#364)
by thomas
21:20 queued 30s
created

EcAdapter::doSignCompact()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 14
Code Lines 8

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 0
CRAP Score 2

Importance

Changes 0
Metric Value
cc 1
eloc 8
c 0
b 0
f 0
nc 1
nop 3
dl 0
loc 14
ccs 0
cts 9
cp 0
crap 2
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 19
    public function __construct(Math $math, GeneratorPoint $generator)
39
    {
40 19
        $this->math = $math;
41 19
        $this->generator = $generator;
42 19
    }
43
44
    /**
45
     * @return Math
46
     */
47 260
    public function getMath()
48
    {
49 260
        return $this->math;
50
    }
51
52
    /**
53
     * @return GeneratorPoint
54
     */
55 185
    public function getGenerator()
56
    {
57 185
        return $this->generator;
58
    }
59
60
    /**
61
     * @param \GMP $scalar
62
     * @param bool|false $compressed
63
     * @return PrivateKey
64
     */
65 35
    public function getPrivateKey(\GMP $scalar, $compressed = false)
66
    {
67 35
        return new PrivateKey($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 37
    public function getPublicKey(PointInterface $point, $compressed = false)
76
    {
77 37
        return new PublicKey($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
     */
96 143
    private function doVerify(BufferInterface $messageHash, PublicKey $publicKey, Signature $signature)
97
    {
98 143
        $hash = gmp_init($messageHash->getHex(), 16);
99 143
        $signer = new Signer($this->math);
100 143
        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
     */
109 143
    public function verify(BufferInterface $messageHash, PublicKeyInterface $publicKey, SignatureInterface $signature)
110
    {
111
        /** @var PublicKey $publicKey */
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        /** @var Signature $signature */
113 143
        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 28
    private function doSign(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
123
    {
124 28
        $rbg = $rbg ?: new Rfc6979($this, $privateKey, $messageHash);
125 28
        $randomK = gmp_init($rbg->bytes(32)->getHex(), 16);
126 28
        $hash = gmp_init($messageHash->getHex(), 16);
127
128 28
        $signer = new Signer($this->math);
129 28
        $signature = $signer->sign($privateKey, $hash, $randomK);
130 28
        $s = $signature->getS();
131
132
        // if s is less than half the curve order, invert s
133 28
        if (!$this->validateSignatureElement($s, true)) {
134 10
            $s = $this->math->sub($this->generator->getOrder(), $s);
135 10
        }
136
137 28
        return new Signature($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 28
    public function sign(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
148
    {
149
        /** @var PrivateKey $privateKey */
150 28
        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 3
    public function recover(BufferInterface $messageHash, CompactSignatureInterface $signature)
160
    {
161 3
        $math = $this->getMath();
162 3
        $G = $this->getGenerator();
163
164 3
        $zero = gmp_init(0);
165 3
        $one = gmp_init(1);
166
167 3
        $r = $signature->getR();
168 3
        $s = $signature->getS();
169 3
        $recGMP = gmp_init($signature->getRecoveryId(), 10);
170 3
        $isYEven = $math->cmp($math->bitwiseAnd($recGMP, $one), $zero) !== 0;
171 3
        $isSecondKey = $math->cmp($math->bitwiseAnd($recGMP, gmp_init(2)), $zero) !== 0;
172 3
        $curve = $G->getCurve();
173
174
        // Precalculate (p + 1) / 4 where p is the field order
175 3
        $p_over_four = $math->div($math->add($curve->getPrime(), $one), gmp_init(4));
176
177
        // 1.1 Compute x
178 3
        if (!$isSecondKey) {
179 3
            $x = $r;
180 3
        } else {
181 3
            $x = $math->add($r, $G->getOrder());
182
        }
183
184
        // 1.3 Convert x to point
185 3
        $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 3
        $beta = $math->powmod($alpha, $p_over_four, $curve->getPrime());
187
188
        // If beta is even, but y isn't or vice versa, then convert it,
189
        // otherwise we're done and y == beta.
190 3
        if ($math->isEven($beta) === $isYEven) {
191 3
            $y = $math->sub($curve->getPrime(), $beta);
192 3
        } else {
193 3
            $y = $beta;
194
        }
195
196
        // 1.4 Check that nR is at infinity (implicitly done in constructor)
197 3
        $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 3
        $point_negate = function (PointInterface $p) use ($math, $G) {
200 3
            return $G->getCurve()->getPoint($p->getX(), $math->mul($p->getY(), gmp_init('-1', 10)));
201 3
        };
202
203
        // 1.6.1 Compute a candidate public key Q = r^-1 (sR - eG)
204 3
        $rInv = $math->inverseMod($r, $G->getOrder());
205 3
        $eGNeg = $point_negate($G->mul($messageHash->getGmp()));
206 3
        $Q = $R->mul($s)->add($eGNeg)->mul($rInv);
207
208
        // 1.6.2 Test Q as a public key
209 3
        $Qk = new PublicKey($this, $Q, $signature->isCompressed());
210 3
        if ($this->verify($messageHash, $Qk, $signature->convert())) {
211
            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 3
    public function calcPubKeyRecoveryParam(\GMP $r, \GMP $s, BufferInterface $messageHash, PublicKey $publicKey)
228
    {
229 3
        $Q = $publicKey->getPoint();
230 3
        for ($i = 0; $i < 4; $i++) {
231
            try {
232 3
                $recover = $this->recover($messageHash, new CompactSignature($this, $r, $s, $i, $publicKey->isCompressed()));
233
                if ($Q->equals($recover->getPoint())) {
234
                    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
    private function doSignCompact(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
252
    {
253
        $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
        return new CompactSignature(
258
            $this,
259
            $sign->getR(),
260
            $sign->getS(),
261
            $this->calcPubKeyRecoveryParam($sign->getR(), $sign->getS(), $messageHash, $privateKey->getPublicKey()),
262
            $privateKey->isCompressed()
263
        );
264
    }
265
266
    /**
267
     * @param PrivateKeyInterface $privateKey
268
     * @param BufferInterface $messageHash
269
     * @param RbgInterface $rbg
270
     * @return CompactSignature
271
     */
272
    public function signCompact(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
273
    {
274
        /** @var PrivateKey $privateKey */
275
        return $this->doSignCompact($messageHash, $privateKey, $rbg);
276
    }
277
278
    /**
279
     * @param BufferInterface $privateKey
280
     * @return bool
281
     */
282 35
    public function validatePrivateKey(BufferInterface $privateKey)
283
    {
284 35
        $math = $this->math;
285 35
        $scalar = $privateKey->getGmp();
286 35
        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 34
    public function validateSignatureElement(\GMP $element, $half = false)
295
    {
296 34
        $math = $this->getMath();
297 34
        $against = $this->getGenerator()->getOrder();
298 34
        if ($half) {
299 34
            $against = $math->rightShift($against, 1);
300 34
        }
301
302 34
        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
     */
310 214
    public function publicKeyFromBuffer(BufferInterface $publicKey)
311
    {
312 214
        $prefix = $publicKey->slice(0, 1)->getBinary();
313 214
        $size = $publicKey->getSize();
314 214
        $compressed = false;
315 214
        if ($prefix == PublicKey::KEY_UNCOMPRESSED || $prefix === "\x06" || $prefix === "\x07") {
316 108
            if ($size !== PublicKey::LENGTH_UNCOMPRESSED) {
317 2
                throw new \Exception('Invalid length for uncompressed key');
318
            }
319 212
        } else if ($prefix === PublicKey::KEY_COMPRESSED_EVEN || $prefix === PublicKey::KEY_COMPRESSED_ODD) {
320 104
            if ($size !== PublicKey::LENGTH_COMPRESSED) {
321
                throw new \Exception('Invalid length for compressed key');
322
            }
323 104
            $compressed = true;
324 104
        } else {
325 2
            throw new \Exception('Unknown public key prefix');
326
        }
327
        
328 210
        $x = $publicKey->slice(1, 32)->getGmp();
329 210
        $curve = $this->generator->getCurve();
330
        $y = $compressed
331 210
            ? $curve->recoverYfromX($prefix === PublicKey::KEY_COMPRESSED_ODD, $x)
332 210
            : $publicKey->slice(33, 32)->getGmp();
333
334 210
        return new PublicKey(
335 210
            $this,
336 210
            $curve->getPoint($x, $y),
337 210
            $compressed,
338
            $prefix
339 210
        );
340
    }
341
}
342