BitWasp\Bitcoin\Script\Interpreter\Interpreter::verify()

Complexity

Conditions	35
Paths	1176

Size

Total Lines	121
Code Lines	61

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	59
CRAP Score	35.1388

Importance

Changes	1
Bugs	0	Features	0

<?php
    public function verify(ScriptInterface $scriptSig, ScriptInterface $scriptPubKey, int $flags, CheckerBase $checker, ScriptWitnessInterface $witness = null): bool
    {
        static $emptyWitness = null;
        if ($emptyWitness === null) {
            $emptyWitness = new ScriptWitness();
        }

        $witness = is_null($witness) ? $emptyWitness : $witness;

        if (($flags & self::VERIFY_SIGPUSHONLY) !== 0 && !$scriptSig->isPushOnly()) {
            return false;
        }

        $stack = new Stack();
        if (!$this->evaluate($scriptSig, $stack, SigHash::V0, $flags, $checker)) {
            return false;
        }

        $backup = [];
        if ($flags & self::VERIFY_P2SH) {
            foreach ($stack as $s) {
                $backup[] = $s;
            }
        }

        if (!$this->evaluate($scriptPubKey, $stack, SigHash::V0, $flags, $checker)) {
            return false;
        }

        if ($stack->isEmpty()) {
            return false;
        }

        if (false === $this->castToBool($stack[-1])) {
            return false;
        }

        $program = null;
        if ($flags & self::VERIFY_WITNESS) {
            if ($scriptPubKey->isWitness($program)) {
                /** @var WitnessProgram $program */
                if ($scriptSig->getBuffer()->getSize() !== 0) {
                    return false;
                }

                if (!$this->verifyWitnessProgram($program, $witness, $flags, $checker)) {
                    return false;
                }

                $stack->resize(1);
            }
        }

        if ($flags & self::VERIFY_P2SH && (new OutputClassifier())->isPayToScriptHash($scriptPubKey)) {
            if (!$scriptSig->isPushOnly()) {
                return false;
            }

            $stack = new Stack();
            foreach ($backup as $i) {
                $stack->push($i);
            }

            // Restore mainStack to how it was after evaluating scriptSig
            if ($stack->isEmpty()) {
                return false;
            }

            // Load redeemscript as the scriptPubKey
            $scriptPubKey = new Script($stack->bottom());
            $stack->pop();

            if (!$this->evaluate($scriptPubKey, $stack, 0, $flags, $checker)) {
                return false;
            }

            if ($stack->isEmpty()) {
                return false;
            }

            if (!$this->castToBool($stack->bottom())) {
                return false;
            }

            if ($flags & self::VERIFY_WITNESS) {
                if ($scriptPubKey->isWitness($program)) {
                    /** @var WitnessProgram $program */
                    if (!$scriptSig->equals(ScriptFactory::sequence([$scriptPubKey->getBuffer()]))) {
                        return false; // SCRIPT_ERR_WITNESS_MALLEATED_P2SH
                    }

                    if (!$this->verifyWitnessProgram($program, $witness, $flags, $checker)) {
                        return false;
                    }

                    $stack->resize(1);
                }
            }
        }

        if ($flags & self::VERIFY_CLEAN_STACK) {
            if (!($flags & self::VERIFY_P2SH !== 0) && ($flags & self::VERIFY_WITNESS !== 0)) {
                return false; // implied flags required
            }

            if (count($stack) !== 1) {
                return false; // Cleanstack
            }
        }

        if ($flags & self::VERIFY_WITNESS) {
            if (!$flags & self::VERIFY_P2SH) {
                return false; //
            }

            if ($program === null && !$witness->isNull()) {
                return false; // SCRIPT_ERR_WITNESS_UNEXPECTED
            }
        }

        return true;
    }