// Copyright © 2017-2020 Trust Wallet.

//

// This file is part of Trust. The full Trust copyright notice, including

// terms governing use, modification, and redistribution, is contained in the

// file LICENSE at the root of the source code distribution tree.

#include "Crc.h"

#include <boost/crc.hpp> // for boost::crc_32_type

#include <string>

using namespace TW;

uint16_t Crc::crc16(uint8_t* bytes, uint32_t length) {

// Calculate checksum for existing bytes

uint16_t crc = 0x0000;

const uint16_t polynomial = 0x1021;

for (auto i = 0; i < length; i++) {

const auto byte = bytes[i];

for (auto bitidx = 0; bitidx < 8; bitidx++) {

const auto bit = ((byte >> (7 - bitidx) & 1) == 1);

const auto c15 = ((crc >> 15 & 1) == 1);

crc <<= 1;

if (c15 ^ bit) {

crc ^= polynomial;

}

}

}

return crc & 0xffff;

}

uint32_t Crc::crc32(const Data& data)

{

boost::crc_32_type result;

result.process_bytes((const void*)data.data(), data.size());

return (uint32_t)result.checksum();

}

uint32_t Crc::crc32C(const Data& data)

{

using crc_32c_type = boost::crc_optimal<32, 0x1EDC6F41, 0xFFFFFFFF, 0xFFFFFFFF, true, true>;

crc_32c_type result;

result.process_bytes((const void*)data.data(), data.size());

return (uint32_t)result.checksum();

}