Method Unserialize

src/script/sign.h:600–703

    template <typename Stream>
    inline void Unserialize(Stream& s) {
        // Read the magic bytes
        uint8_t magic[5];
        s >> magic;
        if (!std::equal(magic, magic + 5, PSBT_MAGIC_BYTES)) {
            throw std::ios_base::failure("Invalid PSBT magic bytes");
        }

        // Read global data
        bool found_sep = false;
        while(!s.empty()) {
            // Read
            std::vector<unsigned char> key;
            s >> key;

            // the key is empty if that was actually a separator byte
            // This is a special case for key lengths 0 as those are not allowed (except for separator)
            if (key.empty()) {
                found_sep = true;
                break;
            }

            // First byte of key is the type
            unsigned char type = key[0];

            // Do stuff based on type
            switch(type) {
                case PSBT_GLOBAL_UNSIGNED_TX:
                {
                    if (tx) {
                        throw std::ios_base::failure("Duplicate Key, unsigned tx already provided");
                    } else if (key.size() != 1) {
                        throw std::ios_base::failure("Global unsigned tx key is more than one byte type");
                    }
                    CMutableTransaction mtx;
                    // Set the stream to serialize with non-witness since this should always be non-witness
                    OverrideStream<Stream> os(&s, s.GetType(), s.GetVersion() | SERIALIZE_TRANSACTION_NO_WITNESS);
                    UnserializeFromVector(os, mtx);
                    tx = std::move(mtx);
                    // Make sure that all scriptSigs and scriptWitnesses are empty
                    for (const CTxIn& txin : tx->vin) {
                        if (!txin.scriptSig.empty() || !txin.scriptWitness.IsNull()) {
                            throw std::ios_base::failure("Unsigned tx does not have empty scriptSigs and scriptWitnesses.");
                        }
                    }
                    break;
                }
                // Unknown stuff
                default: {
                    if (unknown.count(key) > 0) {
                        throw std::ios_base::failure("Duplicate Key, key for unknown value already provided");
                    }
                    // Read in the value
                    std::vector<unsigned char> val_bytes;
                    s >> val_bytes;
                    unknown.emplace(std::move(key), std::move(val_bytes));
                }
            }