Completed
Push — master ( e12674...2b8220 )
by thomas
28:40
created

EcAdapter::publicKeyFromBuffer()   D

Complexity

Conditions 9
Paths 7

Size

Total Lines 31
Code Lines 23

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 21
CRAP Score 9.0076

Importance

Changes 0
Metric Value
cc 9
eloc 23
nc 7
nop 1
dl 0
loc 31
ccs 21
cts 22
cp 0.9545
crap 9.0076
rs 4.909
c 0
b 0
f 0
1
<?php
2
3
namespace BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Adapter;
4
5
use BitWasp\Bitcoin\Crypto\EcAdapter\Adapter\EcAdapterInterface;
6
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PrivateKey;
7
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PublicKey;
8
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Signature\CompactSignature;
9
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Signature\Signature;
10
use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PrivateKeyInterface;
11
use BitWasp\Bitcoin\Crypto\EcAdapter\Key\PublicKeyInterface;
12
use BitWasp\Bitcoin\Crypto\EcAdapter\Signature\CompactSignatureInterface;
13
use BitWasp\Bitcoin\Crypto\EcAdapter\Signature\SignatureInterface;
14
use BitWasp\Bitcoin\Crypto\Random\RbgInterface;
15
use BitWasp\Bitcoin\Crypto\Random\Rfc6979;
16
use BitWasp\Bitcoin\Math\Math;
17
use BitWasp\Buffertools\BufferInterface;
18
use Mdanter\Ecc\Crypto\Signature\Signer;
19
use Mdanter\Ecc\Primitives\GeneratorPoint;
20
use Mdanter\Ecc\Primitives\PointInterface;
21
22
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 13
    public function __construct(Math $math, GeneratorPoint $generator)
39
    {
40 13
        $this->math = $math;
41 13
        $this->generator = $generator;
42 13
    }
43
44
    /**
45
     * @return Math
46
     */
47 353
    public function getMath()
48
    {
49 353
        return $this->math;
50
    }
51
52
    /**
53
     * @return GeneratorPoint
54
     */
55 193
    public function getGenerator()
56
    {
57 193
        return $this->generator;
58
    }
59
60
    /**
61
     * @param \GMP $scalar
62
     * @param bool|false $compressed
63
     * @return PrivateKey
64
     */
65 63
    public function getPrivateKey(\GMP $scalar, $compressed = false)
66
    {
67 63
        return new PrivateKey($this, $scalar, $compressed);
68
    }
69
70
    /**
71
     * @param PointInterface $point
72
     * @param bool|false $compressed
73
     * @return PublicKey
74
     */
75 73
    public function getPublicKey(PointInterface $point, $compressed = false)
76
    {
77 73
        return new PublicKey($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
     */
96 129
    private function doVerify(BufferInterface $messageHash, PublicKey $publicKey, Signature $signature)
97
    {
98 129
        $hash = gmp_init($messageHash->getHex(), 16);
99 129
        $signer = new Signer($this->math);
100 129
        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
     */
109 129
    public function verify(BufferInterface $messageHash, PublicKeyInterface $publicKey, SignatureInterface $signature)
110
    {
111
        /** @var PublicKey $publicKey */
112
        /** @var Signature $signature */
113 129
        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 66
    private function doSign(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
123
    {
124 66
        $rbg = $rbg ?: new Rfc6979($this, $privateKey, $messageHash);
125 66
        $randomK = gmp_init($rbg->bytes(32)->getHex(), 16);
126 66
        $hash = gmp_init($messageHash->getHex(), 16);
127
128 66
        $signer = new Signer($this->math);
129 66
        $signature = $signer->sign($privateKey, $hash, $randomK);
130 66
        $s = $signature->getS();
131
132
        // if s is less than half the curve order, invert s
133 66
        if (!$this->validateSignatureElement($s, true)) {
134 37
            $s = $this->math->sub($this->generator->getOrder(), $s);
135
        }
136
137 66
        return new Signature($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 66
    public function sign(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
148
    {
149
        /** @var PrivateKey $privateKey */
150 66
        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 8
    public function recover(BufferInterface $messageHash, CompactSignatureInterface $signature)
160
    {
161 8
        $math = $this->getMath();
162 8
        $G = $this->getGenerator();
163
164 8
        $zero = gmp_init(0);
165 8
        $one = gmp_init(1);
166
167 8
        $r = $signature->getR();
168 8
        $s = $signature->getS();
169 8
        $recGMP = gmp_init($signature->getRecoveryId(), 10);
170 8
        $isYEven = $math->cmp($math->bitwiseAnd($recGMP, $one), $zero) !== 0;
171 8
        $isSecondKey = $math->cmp($math->bitwiseAnd($recGMP, gmp_init(2)), $zero) !== 0;
172 8
        $curve = $G->getCurve();
173
174
        // Precalculate (p + 1) / 4 where p is the field order
175 8
        $p_over_four = $math->div($math->add($curve->getPrime(), $one), gmp_init(4));
176
177
        // 1.1 Compute x
178 8
        if (!$isSecondKey) {
179 8
            $x = $r;
180
        } else {
181 2
            $x = $math->add($r, $G->getOrder());
182
        }
183
184
        // 1.3 Convert x to point
185 8
        $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 8
        $beta = $math->powmod($alpha, $p_over_four, $curve->getPrime());
187
188
        // If beta is even, but y isn't or vice versa, then convert it,
189
        // otherwise we're done and y=beta.
190 8
        if ($math->isEven($beta) === $isYEven) {
191 7
            $y = $math->sub($curve->getPrime(), $beta);
192
        } else {
193 7
            $y = $beta;
194
        }
195
196
        // 1.4 Check that nR is at infinity (implicitly done in constructor)
197 8
        $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 8
        $point_negate = function (PointInterface $p) use ($math, $G) {
200 8
            return $G->getCurve()->getPoint($p->getX(), $math->mul($p->getY(), gmp_init('-1', 10)));
201 8
        };
202
203
        // 1.6.1 Compute a candidate public key Q = r^-1 (sR - eG)
204 8
        $rInv = $math->inverseMod($r, $G->getOrder());
205 8
        $eGNeg = $point_negate($G->mul($messageHash->getGmp()));
206 8
        $Q = $R->mul($s)->add($eGNeg)->mul($rInv);
207
208
        // 1.6.2 Test Q as a public key
209 8
        $Qk = new PublicKey($this, $Q, $signature->isCompressed());
210 8
        if ($this->verify($messageHash, $Qk, $signature->convert())) {
211 6
            return $Qk;
212
        }
213
214 2
        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 7
    public function calcPubKeyRecoveryParam(\GMP $r, \GMP $s, BufferInterface $messageHash, PublicKey $publicKey)
228
    {
229 7
        $Q = $publicKey->getPoint();
230 7
        for ($i = 0; $i < 4; $i++) {
231
            try {
232 7
                $recover = $this->recover($messageHash, new CompactSignature($this, $r, $s, $i, $publicKey->isCompressed()));
233 5
                if ($Q->equals($recover->getPoint())) {
234 5
                    return $i;
235
                }
236 2
            } catch (\Exception $e) {
237 2
                continue;
238
            }
239
        }
240
241 2
        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 5
    private function doSignCompact(BufferInterface $messageHash, PrivateKey $privateKey, RbgInterface $rbg = null)
252
    {
253 5
        $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 5
        return new CompactSignature(
258 5
            $this,
259 5
            $sign->getR(),
260 5
            $sign->getS(),
261 5
            $this->calcPubKeyRecoveryParam($sign->getR(), $sign->getS(), $messageHash, $privateKey->getPublicKey()),
262 5
            $privateKey->isCompressed()
263
        );
264
    }
265
266
    /**
267
     * @param PrivateKeyInterface $privateKey
268
     * @param BufferInterface $messageHash
269
     * @param RbgInterface $rbg
270
     * @return CompactSignature
271
     */
272 5
    public function signCompact(BufferInterface $messageHash, PrivateKeyInterface $privateKey, RbgInterface $rbg = null)
273
    {
274
        /** @var PrivateKey $privateKey */
275 5
        return $this->doSignCompact($messageHash, $privateKey, $rbg);
276
    }
277
278
    /**
279
     * @param BufferInterface $privateKey
280
     * @return bool
281
     */
282 65
    public function validatePrivateKey(BufferInterface $privateKey)
283
    {
284 65
        $math = $this->math;
285 65
        $scalar = $privateKey->getGmp();
286 65
        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 69
    public function validateSignatureElement(\GMP $element, $half = false)
295
    {
296 69
        $math = $this->getMath();
297 69
        $against = $this->getGenerator()->getOrder();
298 69
        if ($half) {
299 69
            $against = $math->rightShift($against, 1);
300
        }
301
302 69
        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
     */
310 192
    public function publicKeyFromBuffer(BufferInterface $publicKey)
311
    {
312 192
        $prefix = $publicKey->slice(0, 1)->getBinary();
313 192
        $size = $publicKey->getSize();
314 192
        $compressed = false;
315 192
        if ($prefix === PublicKey::KEY_UNCOMPRESSED || $prefix === "\x06" || $prefix === "\x07") {
316 69
            if ($size !== PublicKey::LENGTH_UNCOMPRESSED) {
317 69
                throw new \Exception('Invalid length for uncompressed key');
318
            }
319 133
        } else if ($prefix === PublicKey::KEY_COMPRESSED_EVEN || $prefix === PublicKey::KEY_COMPRESSED_ODD) {
320 132
            if ($size !== PublicKey::LENGTH_COMPRESSED) {
321
                throw new \Exception('Invalid length for compressed key');
322
            }
323 132
            $compressed = true;
324
        } else {
325 1
            throw new \Exception('Unknown public key prefix');
326
        }
327
        
328 190
        $x = $publicKey->slice(1, 32)->getGmp();
329 190
        $curve = $this->generator->getCurve();
330 190
        $y = $compressed
331 132
            ? $curve->recoverYfromX($prefix === PublicKey::KEY_COMPRESSED_ODD, $x)
332 190
            : $publicKey->slice(33, 32)->getGmp();
333
334 190
        return new PublicKey(
335 190
            $this,
336 190
            $curve->getPoint($x, $y),
337 190
            $compressed,
338 190
            $prefix
339
        );
340
    }
341
}
342