SIGHASH2 pseudo code

const int inputtype = nHashType & SIGHASH2_INPUT_MASK;
const int outputtype = nHashType & SIGHASH2_OUTPUT_MASK;
CHashWriter ss();

ss << static_cast<uint8_t>(nHashType);

// tx-level data
ss << txTo.nVersion;

if (inputtype == SIGHASH2_ALL) {
	ss << single_sha256_prevouts;
	ss << single_sha256_amounts;
	ss << single_sha256_sequence;
}
// else { do nothing }

if (outputtype == SIGHASH2_ALLOUTPUT) {
	ss << single_sha256_outputs;
}
else if (outputtype == SIGHASH2_SINGLEOUTPUT) {
	assert(nIn < txTo.vout.size());
	ss << txTo.vout[nIn]; 
}
// else if (outputtype == SIGHASH2_NOOUTPUT) { do nothing }
else if (outputtype != SIGHASH2_NOOUTPUT) {
	assert(!"invalid SIGHASH2");
}

ss << txTo.nLockTime;
// input-level data
if (inputtype == SIGHASH2_ALL) {
	ss << static_cast<uint16_t>(nIn);
}
else {
	if (inputtype == SIGHASH2_SINGLEINPUT) {
		ss << txTo.vin[nIn].prevout;
	}
	ss << amount;
	ss << txTo.vin[nIn].nSequence;
}

if (inputtype == SIGHASH2_NOINPUT_MASKEDSCRIPT) {
	ss << static_cast<uint8_t>(scriptPubKey.IsPayToScriptHash());
}
else {
	ss << scriptPubKey;
}

// script-level data
if (is_direct_spending) {
	assert(inputtype != SIGHASH2_NOINPUT_MASKEDSCRIPT);
}
else {
	if (inputtype == SIGHASH2_NOINPUT_MASKEDSCRIPT) {
		ss << single_sha256_masked_scriptcode;
	}
	else {
		ss << single_sha256_scriptcode;
	}
	ss << static_cast<uint8_t>(codeseparator_position);
}


return ss.GetSingleSHA256();