solidity/test/Metadata.cpp

/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * @date 2017
 * Metadata processing helpers.
 */

#include <string>
#include <iostream>
#include <libdevcore/JSON.h>
#include <test/Metadata.h>

using namespace std;

namespace dev
{
namespace test
{

bytes bytecodeSansMetadata(bytes const& _bytecode)
{
	unsigned size = _bytecode.size();
	if (size < 5)
		return bytes{};
	size_t metadataSize = (_bytecode[size - 2] << 8) + _bytecode[size - 1];
	if (size < (metadataSize + 2))
		return bytes{};
	// Sanity check: assume the first byte is a fixed-size CBOR array with either 1 or 2 entries
	unsigned char firstByte = _bytecode[size - metadataSize - 2];
	if (firstByte != 0xa1 && firstByte != 0xa2)
		return bytes{};
	return bytes(_bytecode.begin(), _bytecode.end() - metadataSize - 2);
}

string bytecodeSansMetadata(string const& _bytecode)
{
	return toHex(bytecodeSansMetadata(fromHex(_bytecode, WhenError::Throw)));
}

bool isValidMetadata(string const& _metadata)
{
	Json::Value metadata;
	if (!jsonParseStrict(_metadata, metadata))
		return false;

	if (
		!metadata.isObject() ||
		!metadata.isMember("version") ||
		!metadata.isMember("language") ||
		!metadata.isMember("compiler") ||
		!metadata.isMember("settings") ||
		!metadata.isMember("sources") ||
		!metadata.isMember("output") ||
		!metadata["settings"].isMember("evmVersion")
	)
		return false;

	if (!metadata["version"].isNumeric() || metadata["version"] != 1)
		return false;

	if (!metadata["language"].isString() || metadata["language"].asString() != "Solidity")
		return false;

	/// @TODO add more strict checks

	return true;
}

}
} // end namespaces