Checker::isLowDerSignature() - Code Metrics - Inspection of "Multiple branches" - Bit-Wasp/bitcoin-php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#525)

by thomas

created 2017-09-03 23:19 UTC

Checker::isLowDerSignature() A

↳ Parent: Checker

Complexity

Conditions	2
Paths	2

Size

Total Lines	13
Code Lines	8

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	8
CRAP Score	2

Importance

Changes

Metric	Value
cc	2
eloc	8
nc	2
nop	1
dl	0
loc	13
ccs	8
cts	8
cp	1
crap	2
rs	9.4285
c	0
b	0
f	0

<?php

namespace BitWasp\Bitcoin\Script\Interpreter;

use BitWasp\Bitcoin\Crypto\EcAdapter\Adapter\EcAdapterInterface;
use BitWasp\Bitcoin\Crypto\EcAdapter\EcSerializer;
use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PublicKey;
use BitWasp\Bitcoin\Crypto\EcAdapter\Serializer\Key\PublicKeySerializerInterface;
use BitWasp\Bitcoin\Crypto\EcAdapter\Serializer\Signature\DerSignatureSerializerInterface;
use BitWasp\Bitcoin\Exceptions\ScriptRuntimeException;
use BitWasp\Bitcoin\Exceptions\SignatureNotCanonical;
use BitWasp\Bitcoin\Locktime;
use BitWasp\Bitcoin\Script\ScriptInterface;
use BitWasp\Bitcoin\Serializer\Signature\TransactionSignatureSerializer;
use BitWasp\Bitcoin\Serializer\Transaction\TransactionSerializer;
use BitWasp\Bitcoin\Signature\TransactionSignature;
use BitWasp\Bitcoin\Transaction\SignatureHash\Hasher;
use BitWasp\Bitcoin\Transaction\SignatureHash\SigHash;
use BitWasp\Bitcoin\Transaction\SignatureHash\V1Hasher;
use BitWasp\Bitcoin\Transaction\TransactionInputInterface;
use BitWasp\Bitcoin\Transaction\TransactionInterface;
use BitWasp\Buffertools\Buffer;
use BitWasp\Buffertools\BufferInterface;

class Checker
{
    /**
     * @var EcAdapterInterface
     */
    protected $adapter;

    /**
     * @var TransactionInterface
     */
    protected $transaction;

    /**
     * @var int
     */
    protected $nInput;

    /**
     * @var int|string
     */
    protected $amount;

    /**
     * @var Hasher
     */
    protected $hasherV0;

    /**
     * @var array
     */
    protected $sigHashCache = [];

    /**
     * @var array
     */
    protected $sigCache = [];

    /**
     * @var TransactionSignatureSerializer
     */
    private $sigSerializer;

    /**
     * @var PublicKeySerializerInterface
     */
    private $pubKeySerializer;

    /**
     * @var int
     */
    protected $sigHashOptionalBits = SigHash::ANYONECANPAY;

    /**
     * Checker constructor.
     * @param EcAdapterInterface $ecAdapter
     * @param TransactionInterface $transaction
     * @param int $nInput
     * @param int $amount
     * @param TransactionSignatureSerializer|null $sigSerializer
     * @param PublicKeySerializerInterface|null $pubKeySerializer
     */
    public function __construct(EcAdapterInterface $ecAdapter, TransactionInterface $transaction, $nInput, $amount, TransactionSignatureSerializer $sigSerializer = null, PublicKeySerializerInterface $pubKeySerializer = null)
    {
        $this->sigSerializer = $sigSerializer ?: new TransactionSignatureSerializer(EcSerializer::getSerializer(DerSignatureSerializerInterface::class, true, $ecAdapter));
        $this->pubKeySerializer = $pubKeySerializer ?: EcSerializer::getSerializer(PublicKeySerializerInterface::class, true, $ecAdapter);
        $this->adapter = $ecAdapter;
        $this->transaction = $transaction;
        $this->nInput = $nInput;
        $this->amount = $amount;
    }

    /**
     * @param BufferInterface $signature
     * @return bool
     */
    public function isValidSignatureEncoding(BufferInterface $signature)
    {
        try {
            TransactionSignature::isDERSignature($signature);
            return true;
        } catch (SignatureNotCanonical $e) {
            /* In any case, we will return false outside this block */
        }

        return false;
    }

    /**
     * @param BufferInterface $signature
     * @return bool
     * @throws ScriptRuntimeException
     * @throws \Exception
     */
    public function isLowDerSignature(BufferInterface $signature)
    {
        if (!$this->isValidSignatureEncoding($signature)) {
            throw new ScriptRuntimeException(Interpreter::VERIFY_DERSIG, 'Signature with incorrect encoding');
        }

        $binary = $signature->getBinary();
        $nLenR = ord($binary[3]);
        $nLenS = ord($binary[5 + $nLenR]);
        $s = $signature->slice(6 + $nLenR, $nLenS)->getGmp();

        return $this->adapter->validateSignatureElement($s, true);
    }

    /**
     * @param int $hashType
     * @return bool
     */
    public function isDefinedHashtype($hashType)
    {
        $nHashType = $hashType & (~($this->sigHashOptionalBits));

        return !(($nHashType < SigHash::ALL) || ($nHashType > SigHash::SINGLE));
    }

    /**
     * Determine whether the sighash byte appended to the signature encodes
     * a valid sighash type.
     *
     * @param BufferInterface $signature
     * @return bool
     */
    public function isDefinedHashtypeSignature(BufferInterface $signature)
    {
        if ($signature->getSize() === 0) {
            return false;
        }

        $binary = $signature->getBinary();
        return $this->isDefinedHashtype(ord(substr($binary, -1)));
    }

    /**
     * @param BufferInterface $signature
     * @param int $flags
     * @return $this
     * @throws \BitWasp\Bitcoin\Exceptions\ScriptRuntimeException
     */
    public function checkSignatureEncoding(BufferInterface $signature, $flags)
    {
        if ($signature->getSize() === 0) {
            return $this;
        }

        if (($flags & (Interpreter::VERIFY_DERSIG | Interpreter::VERIFY_LOW_S | Interpreter::VERIFY_STRICTENC)) !== 0 && !$this->isValidSignatureEncoding($signature)) {
            throw new ScriptRuntimeException(Interpreter::VERIFY_DERSIG, 'Signature with incorrect encoding');
        } else if (($flags & Interpreter::VERIFY_LOW_S) !== 0 && !$this->isLowDerSignature($signature)) {
            throw new ScriptRuntimeException(Interpreter::VERIFY_LOW_S, 'Signature s element was not low');
        } else if (($flags & Interpreter::VERIFY_STRICTENC) !== 0 && !$this->isDefinedHashtypeSignature($signature)) {
            throw new ScriptRuntimeException(Interpreter::VERIFY_STRICTENC, 'Signature with invalid hashtype');
        }

        return $this;
    }

    /**
     * @param BufferInterface $publicKey
     * @param int $flags
     * @return $this
     * @throws \Exception
     */
    public function checkPublicKeyEncoding(BufferInterface $publicKey, $flags)
    {
        if (($flags & Interpreter::VERIFY_STRICTENC) !== 0 && !PublicKey::isCompressedOrUncompressed($publicKey)) {
            throw new ScriptRuntimeException(Interpreter::VERIFY_STRICTENC, 'Public key with incorrect encoding');
        }

        return $this;
    }

    /**
     * @param ScriptInterface $script
     * @param int $sigHashType
     * @param int $sigVersion
     * @return BufferInterface
     */
    public function getSigHash(ScriptInterface $script, $sigHashType, $sigVersion)
    {
        $cacheCheck = $sigVersion . $sigHashType . $script->getBuffer()->getBinary();
        if (!isset($this->sigHashCache[$cacheCheck])) {
            if (SigHash::V1 === $sigVersion) {
                $hasher = new V1Hasher($this->transaction, $this->amount);
            } else {
                if ($this->hasherV0) {
                    $hasher = $this->hasherV0;
                } else {
                    $hasher = $this->hasherV0 = new Hasher($this->transaction, new TransactionSerializer());

                }
            }

            $hash = $hasher->calculate($script, $this->nInput, $sigHashType);
            $this->sigHashCache[$cacheCheck] = $hash->getBinary();
        } else {
            $hash = new Buffer($this->sigHashCache[$cacheCheck], 32, $this->adapter->getMath());
        }

        return $hash;
    }

    /**
     * @param ScriptInterface $script
     * @param BufferInterface $sigBuf
     * @param BufferInterface $keyBuf
     * @param int $sigVersion
     * @param int $flags
     * @return bool
     * @throws ScriptRuntimeException
     */
    public function checkSig(ScriptInterface $script, BufferInterface $sigBuf, BufferInterface $keyBuf, $sigVersion, $flags)
    {
        $this
            ->checkSignatureEncoding($sigBuf, $flags)
            ->checkPublicKeyEncoding($keyBuf, $flags);

        try {
            $cacheCheck = $flags . $sigVersion . $keyBuf->getBinary() . $sigBuf->getBinary();
            if (!isset($this->sigCache[$cacheCheck])) {
                $txSignature = $this->sigSerializer->parse($sigBuf);
                $publicKey = $this->pubKeySerializer->parse($keyBuf);

                $hash = $this->getSigHash($script, $txSignature->getHashType(), $sigVersion);
                $result = $this->sigCache[$cacheCheck] = $this->adapter->verify($hash, $publicKey, $txSignature->getSignature());
            } else {
                $result = $this->sigCache[$cacheCheck];
            }

            return $result;
        } catch (\Exception $e) {
            return false;
        }
    }

    /**
     * @param int $txLockTime
     * @param int $nThreshold
     * @param \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime
     * @return bool
     */
    private function verifyLockTime($txLockTime, $nThreshold, \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime)
    {
        $nTime = $lockTime->getInt();
        if (($txLockTime < $nThreshold && $nTime < $nThreshold) ||
            ($txLockTime >= $nThreshold && $nTime >= $nThreshold)
        ) {
            return false;
        }

        return $nTime >= $txLockTime;
    }

    /**
     * @param \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime
     * @return bool
     */
    public function checkLockTime(\BitWasp\Bitcoin\Script\Interpreter\Number $lockTime)
    {
        if ($this->transaction->getInput($this->nInput)->isFinal()) {
            return false;
        }

        return $this->verifyLockTime($this->transaction->getLockTime(), Locktime::BLOCK_MAX, $lockTime);
    }


    /**
     * @param \BitWasp\Bitcoin\Script\Interpreter\Number $sequence
     * @return bool
     */
    public function checkSequence(\BitWasp\Bitcoin\Script\Interpreter\Number $sequence)
    {
        $txSequence = $this->transaction->getInput($this->nInput)->getSequence();
        if ($this->transaction->getVersion() < 2) {
            return false;
        }

        if (($txSequence & TransactionInputInterface::SEQUENCE_LOCKTIME_DISABLE_FLAG) !== 0) {
            return true;
        }

        $mask = TransactionInputInterface::SEQUENCE_LOCKTIME_TYPE_FLAG | TransactionInputInterface::SEQUENCE_LOCKTIME_MASK;
        return $this->verifyLockTime(
            $txSequence & $mask,
            TransactionInputInterface::SEQUENCE_LOCKTIME_TYPE_FLAG,
            Number::int($sequence->getInt() & $mask)
        );
    }
}


1		<?php
2
3		namespace BitWasp\Bitcoin\Script\Interpreter;
4
5		use BitWasp\Bitcoin\Crypto\EcAdapter\Adapter\EcAdapterInterface;
6		use BitWasp\Bitcoin\Crypto\EcAdapter\EcSerializer;
7		use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\PhpEcc\Key\PublicKey;
8		use BitWasp\Bitcoin\Crypto\EcAdapter\Serializer\Key\PublicKeySerializerInterface;
9		use BitWasp\Bitcoin\Crypto\EcAdapter\Serializer\Signature\DerSignatureSerializerInterface;
10		use BitWasp\Bitcoin\Exceptions\ScriptRuntimeException;
11		use BitWasp\Bitcoin\Exceptions\SignatureNotCanonical;
12		use BitWasp\Bitcoin\Locktime;
13		use BitWasp\Bitcoin\Script\ScriptInterface;
14		use BitWasp\Bitcoin\Serializer\Signature\TransactionSignatureSerializer;
15		use BitWasp\Bitcoin\Serializer\Transaction\TransactionSerializer;
16		use BitWasp\Bitcoin\Signature\TransactionSignature;
17		use BitWasp\Bitcoin\Transaction\SignatureHash\Hasher;
18		use BitWasp\Bitcoin\Transaction\SignatureHash\SigHash;
19		use BitWasp\Bitcoin\Transaction\SignatureHash\V1Hasher;
20		use BitWasp\Bitcoin\Transaction\TransactionInputInterface;
21		use BitWasp\Bitcoin\Transaction\TransactionInterface;
22		use BitWasp\Buffertools\Buffer;
23		use BitWasp\Buffertools\BufferInterface;
24
25		class Checker
26		{
27		/**
28		* @var EcAdapterInterface
29		*/
30		protected $adapter;
31
32		/**
33		* @var TransactionInterface
34		*/
35		protected $transaction;
36
37		/**
38		* @var int
39		*/
40		protected $nInput;
41
42		/**
43		* @var int\|string
44		*/
45		protected $amount;
46
47		/**
48		* @var Hasher
49		*/
50		protected $hasherV0;
51
52		/**
53		* @var array
54		*/
55		protected $sigHashCache = [];
56
57		/**
58		* @var array
59		*/
60		protected $sigCache = [];
61
62		/**
63		* @var TransactionSignatureSerializer
64		*/
65		private $sigSerializer;
66
67		/**
68		* @var PublicKeySerializerInterface
69		*/
70		private $pubKeySerializer;
71
72		/**
73		* @var int
74		*/
75		protected $sigHashOptionalBits = SigHash::ANYONECANPAY;
76
77		/**
78		* Checker constructor.
79		* @param EcAdapterInterface $ecAdapter
80		* @param TransactionInterface $transaction
81		* @param int $nInput
82		* @param int $amount
83		* @param TransactionSignatureSerializer\|null $sigSerializer
84		* @param PublicKeySerializerInterface\|null $pubKeySerializer
85		*/
86	2494	public function __construct(EcAdapterInterface $ecAdapter, TransactionInterface $transaction, $nInput, $amount, TransactionSignatureSerializer $sigSerializer = null, PublicKeySerializerInterface $pubKeySerializer = null)
87		{
88	2494	$this->sigSerializer = $sigSerializer ?: new TransactionSignatureSerializer(EcSerializer::getSerializer(DerSignatureSerializerInterface::class, true, $ecAdapter));
89	2494	$this->pubKeySerializer = $pubKeySerializer ?: EcSerializer::getSerializer(PublicKeySerializerInterface::class, true, $ecAdapter);
90	2494	$this->adapter = $ecAdapter;
91	2494	$this->transaction = $transaction;
92	2494	$this->nInput = $nInput;
93	2494	$this->amount = $amount;
94	2494	}
95
96		/**
97		* @param BufferInterface $signature
98		* @return bool
99		*/
100	106	public function isValidSignatureEncoding(BufferInterface $signature)
101		{
102		try {
103	106	TransactionSignature::isDERSignature($signature);
104	58	return true;
105	52	} catch (SignatureNotCanonical $e) {
106		/* In any case, we will return false outside this block */
107		}
108
109	52	return false;
110		}
111
112		/**
113		* @param BufferInterface $signature
114		* @return bool
115		* @throws ScriptRuntimeException
116		* @throws \Exception
117		*/
118	8	public function isLowDerSignature(BufferInterface $signature)
119		{
120	8	if (!$this->isValidSignatureEncoding($signature)) {
121	2	throw new ScriptRuntimeException(Interpreter::VERIFY_DERSIG, 'Signature with incorrect encoding');
122		}
123
124	6	$binary = $signature->getBinary();
125	6	$nLenR = ord($binary[3]);
126	6	$nLenS = ord($binary[5 + $nLenR]);
127	6	$s = $signature->slice(6 + $nLenR, $nLenS)->getGmp();
128
129	6	return $this->adapter->validateSignatureElement($s, true);
130		}
131
132		/**
133		* @param int $hashType
134		* @return bool
135		*/
136	108	public function isDefinedHashtype($hashType)
137		{
138	108	$nHashType = $hashType & (~($this->sigHashOptionalBits));
139
140	108	return !(($nHashType < SigHash::ALL) \|\| ($nHashType > SigHash::SINGLE));
141		}
142
143		/**
144		* Determine whether the sighash byte appended to the signature encodes
145		* a valid sighash type.
146		*
147		* @param BufferInterface $signature
148		* @return bool
149		*/
150	28	public function isDefinedHashtypeSignature(BufferInterface $signature)
151		{
152	28	if ($signature->getSize() === 0) {
153	2	return false;
154		}
155
156	26	$binary = $signature->getBinary();
157	26	return $this->isDefinedHashtype(ord(substr($binary, -1)));
158		}
159
160		/**
161		* @param BufferInterface $signature
162		* @param int $flags
163		* @return $this
164		* @throws \BitWasp\Bitcoin\Exceptions\ScriptRuntimeException
165		*/
166	324	public function checkSignatureEncoding(BufferInterface $signature, $flags)
167		{
168	324	if ($signature->getSize() === 0) {
169	54	return $this;
170		}
171
172	284	if (($flags & (Interpreter::VERIFY_DERSIG \| Interpreter::VERIFY_LOW_S \| Interpreter::VERIFY_STRICTENC)) !== 0 && !$this->isValidSignatureEncoding($signature)) {
173	50	throw new ScriptRuntimeException(Interpreter::VERIFY_DERSIG, 'Signature with incorrect encoding');
174	238	} else if (($flags & Interpreter::VERIFY_LOW_S) !== 0 && !$this->isLowDerSignature($signature)) {
175	4	throw new ScriptRuntimeException(Interpreter::VERIFY_LOW_S, 'Signature s element was not low');
176	234	} else if (($flags & Interpreter::VERIFY_STRICTENC) !== 0 && !$this->isDefinedHashtypeSignature($signature)) {
177	6	throw new ScriptRuntimeException(Interpreter::VERIFY_STRICTENC, 'Signature with invalid hashtype');
178		}
179
180	228	return $this;
181		}
182
183		/**
184		* @param BufferInterface $publicKey
185		* @param int $flags
186		* @return $this
187		* @throws \Exception
188		*/
189	264	public function checkPublicKeyEncoding(BufferInterface $publicKey, $flags)
190		{
191	264	if (($flags & Interpreter::VERIFY_STRICTENC) !== 0 && !PublicKey::isCompressedOrUncompressed($publicKey)) {
192	12	throw new ScriptRuntimeException(Interpreter::VERIFY_STRICTENC, 'Public key with incorrect encoding');
193		}
194
195	252	return $this;
196		}
197
198		/**
199		* @param ScriptInterface $script
200		* @param int $sigHashType
201		* @param int $sigVersion
202		* @return BufferInterface
203		*/
204	202	public function getSigHash(ScriptInterface $script, $sigHashType, $sigVersion)
205		{
206	202	$cacheCheck = $sigVersion . $sigHashType . $script->getBuffer()->getBinary();
207	202	if (!isset($this->sigHashCache[$cacheCheck])) {
208	202	if (SigHash::V1 === $sigVersion) {
209	60	$hasher = new V1Hasher($this->transaction, $this->amount);
210		} else {
211	144	if ($this->hasherV0) {
212		$hasher = $this->hasherV0;
213		} else {
214	144	$hasher = $this->hasherV0 = new Hasher($this->transaction, new TransactionSerializer());
		0 ignored issues – show Unused Code introduced 2017-08-23 14:27 UTC by Report Bug Copy Issue Report The call to `Hasher::__construct()` has too many arguments starting with `new \BitWasp\Bitcoin\Ser...TransactionSerializer()`. This check compares calls to functions or methods with their respective definitions. If the call has more arguments than are defined, it raises an issue. If a function is defined several times with a different number of parameters, the check may pick up the wrong definition and report false positives. One codebase where this has been known to happen is Wordpress. In this case you can add the `@ignore` PhpDoc annotation to the duplicate definition and it will be ignored. Loading history...
215		}
216		}
217
218	202	$hash = $hasher->calculate($script, $this->nInput, $sigHashType);
219	202	$this->sigHashCache[$cacheCheck] = $hash->getBinary();
220		} else {
221	28	$hash = new Buffer($this->sigHashCache[$cacheCheck], 32, $this->adapter->getMath());
222		}
223
224	202	return $hash;
225		}
226
227		/**
228		* @param ScriptInterface $script
229		* @param BufferInterface $sigBuf
230		* @param BufferInterface $keyBuf
231		* @param int $sigVersion
232		* @param int $flags
233		* @return bool
234		* @throws ScriptRuntimeException
235		*/
236	310	public function checkSig(ScriptInterface $script, BufferInterface $sigBuf, BufferInterface $keyBuf, $sigVersion, $flags)
237		{
238		$this
239	310	->checkSignatureEncoding($sigBuf, $flags)
240	260	->checkPublicKeyEncoding($keyBuf, $flags);
241
242		try {
243	250	$cacheCheck = $flags . $sigVersion . $keyBuf->getBinary() . $sigBuf->getBinary();
244	250	if (!isset($this->sigCache[$cacheCheck])) {
245	250	$txSignature = $this->sigSerializer->parse($sigBuf);
246	196	$publicKey = $this->pubKeySerializer->parse($keyBuf);
247
248	186	$hash = $this->getSigHash($script, $txSignature->getHashType(), $sigVersion);
249	186	$result = $this->sigCache[$cacheCheck] = $this->adapter->verify($hash, $publicKey, $txSignature->getSignature());
250		} else {
251	26	$result = $this->sigCache[$cacheCheck];
252		}
253
254	186	return $result;
255	78	} catch (\Exception $e) {
256	78	return false;
257		}
258		}
259
260		/**
261		* @param int $txLockTime
262		* @param int $nThreshold
263		* @param \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime
264		* @return bool
265		*/
266		private function verifyLockTime($txLockTime, $nThreshold, \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime)
267		{
268		$nTime = $lockTime->getInt();
269		if (($txLockTime < $nThreshold && $nTime < $nThreshold) \|\|
270		($txLockTime >= $nThreshold && $nTime >= $nThreshold)
271		) {
272		return false;
273		}
274
275		return $nTime >= $txLockTime;
276		}
277
278		/**
279		* @param \BitWasp\Bitcoin\Script\Interpreter\Number $lockTime
280		* @return bool
281		*/
282		public function checkLockTime(\BitWasp\Bitcoin\Script\Interpreter\Number $lockTime)
283		{
284		if ($this->transaction->getInput($this->nInput)->isFinal()) {
285		return false;
286		}
287
288		return $this->verifyLockTime($this->transaction->getLockTime(), Locktime::BLOCK_MAX, $lockTime);
289		}
290
291
292		/**
293		* @param \BitWasp\Bitcoin\Script\Interpreter\Number $sequence
294		* @return bool
295		*/
296	4	public function checkSequence(\BitWasp\Bitcoin\Script\Interpreter\Number $sequence)
297		{
298	4	$txSequence = $this->transaction->getInput($this->nInput)->getSequence();
299	4	if ($this->transaction->getVersion() < 2) {
300	4	return false;
301		}
302
303		if (($txSequence & TransactionInputInterface::SEQUENCE_LOCKTIME_DISABLE_FLAG) !== 0) {
304		return true;
305		}
306
307		$mask = TransactionInputInterface::SEQUENCE_LOCKTIME_TYPE_FLAG \| TransactionInputInterface::SEQUENCE_LOCKTIME_MASK;
308		return $this->verifyLockTime(
309		$txSequence & $mask,
310		TransactionInputInterface::SEQUENCE_LOCKTIME_TYPE_FLAG,
311		Number::int($sequence->getInt() & $mask)
312		);
313		}
314		}
315

Bit-Wasp / bitcoin-php

Pull Request — master (#525)

Checker::isLowDerSignature() A

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