bitcoinconsensus.cpp

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#include <script/bitcoinconsensus.h>
 
#include <primitives/transaction.h>
#include <pubkey.h>
#include <script/interpreter.h>
 
namespace {
 
class TxInputStream {
public:
    TxInputStream(const uint8_t *txTo, size_t txToLen)
        : m_data(txTo), m_remaining(txToLen) {}
 
    void read(Span<std::byte> dst) {
        if (dst.size() > m_remaining) {
            throw std::ios_base::failure(std::string(__func__) +
                                         ": end of data");
        }
 
        if (dst.data() == nullptr) {
            throw std::ios_base::failure(std::string(__func__) +
                                         ": bad destination buffer");
        }
 
        if (m_data == nullptr) {
            throw std::ios_base::failure(std::string(__func__) +
                                         ": bad source buffer");
        }
 
        memcpy(dst.data(), m_data, dst.size());
        m_remaining -= dst.size();
        m_data += dst.size();
    }
 
    template <typename T> TxInputStream &operator>>(T &&obj) {
        ::Unserialize(*this, obj);
        return *this;
    }
 
private:
    const uint8_t *m_data;
    size_t m_remaining;
};
 
inline int set_error(bitcoinconsensus_error *ret,
                     bitcoinconsensus_error serror) {
    if (ret) {
        *ret = serror;
    }
 
    return 0;
}
 
struct ECCryptoClosure {
    ECCVerifyHandle handle;
};
 
ECCryptoClosure instance_of_eccryptoclosure;
} // namespace
 
static bool verify_flags(unsigned int flags) {
    return (flags & ~(bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL)) == 0;
}
 
static int verify_script(const uint8_t *scriptPubKey,
                         unsigned int scriptPubKeyLen, Amount amount,
                         const uint8_t *txTo, unsigned int txToLen,
                         unsigned int nIn, unsigned int flags,
                         bitcoinconsensus_error *err) {
    if (!verify_flags(flags)) {
        return set_error(err, bitcoinconsensus_ERR_INVALID_FLAGS);
    }
    try {
        TxInputStream stream{txTo, txToLen};
        CTransaction tx(deserialize, stream);
        if (nIn >= tx.vin.size()) {
            return set_error(err, bitcoinconsensus_ERR_TX_INDEX);
        }
 
        if (GetSerializeSize(tx) != txToLen) {
            return set_error(err, bitcoinconsensus_ERR_TX_SIZE_MISMATCH);
        }
 
        // Regardless of the verification result, the tx did not error.
        set_error(err, bitcoinconsensus_ERR_OK);
 
        PrecomputedTransactionData txdata(tx);
        return VerifyScript(
            tx.vin[nIn].scriptSig,
            CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), flags,
            TransactionSignatureChecker(&tx, nIn, amount, txdata), nullptr);
    } catch (const std::exception &) {
        // Error deserializing
        return set_error(err, bitcoinconsensus_ERR_TX_DESERIALIZE);
    }
}
 
int bitcoinconsensus_verify_script_with_amount(
    const uint8_t *scriptPubKey, unsigned int scriptPubKeyLen, int64_t amount,
    const uint8_t *txTo, unsigned int txToLen, unsigned int nIn,
    unsigned int flags, bitcoinconsensus_error *err) {
    Amount am(amount * SATOSHI);
    return ::verify_script(scriptPubKey, scriptPubKeyLen, am, txTo, txToLen,
                           nIn, flags, err);
}
 
int bitcoinconsensus_verify_script(const uint8_t *scriptPubKey,
                                   unsigned int scriptPubKeyLen,
                                   const uint8_t *txTo, unsigned int txToLen,
                                   unsigned int nIn, unsigned int flags,
                                   bitcoinconsensus_error *err) {
    if (flags & bitcoinconsensus_SCRIPT_ENABLE_SIGHASH_FORKID ||
        flags & bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS_DEPRECATED) {
        return set_error(err, bitcoinconsensus_ERR_AMOUNT_REQUIRED);
    }
 
    return ::verify_script(scriptPubKey, scriptPubKeyLen, Amount::zero(), txTo,
                           txToLen, nIn, flags, err);
}
 
unsigned int bitcoinconsensus_version() {
    // Just use the API version for now
    return BITCOINCONSENSUS_API_VER;
}