CPP/CRC

A very small, fast, header-only, C++ library for generating CRCs

Requirements

C++14 or greater

Features

Can be used to generate arbitrary/custom CRC calculators, and CRC lookup tables at compile time
Header-only, single file, very small backend implementation (<100 lines)
Each CRC function has the signature:

constexpr out_t crc_type::crc_name::calc(const uint8_t *bytes, size_t size, out_t crc = initial_value)

Support for the following algorithms are built-in:
- CRC8::CRC8::calc
- CRC8::CDMA2000::calc
- CRC8::DARC::calc
- CRC8::DVB_S2::calc
- CRC8::EBU::calc
- CRC8::I_CODE::calc
- CRC8::ITU::calc
- CRC8::MAXIM::calc
- CRC8::ROHC::calc
- CRC8::WCDMA::calc
- CRC16::ARC::calc
- CRC16::AUG_CCITT::calc
- CRC16::BUYPASS::calc
- CRC16::CCITT_FALSE::calc
- CRC16::CDMA2000::calc
- CRC16::DDS_110::calc
- CRC16::DECT_R::calc
- CRC16::DECT_X::calc
- CRC16::DNP::calc
- CRC16::EN_13757::calc
- CRC16::GENIBUS::calc
- CRC16::KERMIT::calc
- CRC16::MAXIM::calc
- CRC16::MCRF4XX::calc
- CRC16::MODBUS::calc
- CRC16::RIELLO::calc
- CRC16::T10_DIF::calc
- CRC16::TELEDISK::calc
- CRC16::TMS37157::calc
- CRC16::USB::calc
- CRC16::X_25::calc
- CRC16::XMODEM::calc
- CRC16::A::calc
- CRC32::CRC32::calc
- CRC32::BZIP2::calc
- CRC32::JAMCRC::calc
- CRC32::MPEG_2::calc
- CRC32::POSIX::calc
- CRC32::SATA::calc
- CRC32::XFER::calc
- CRC32::C::calc
- CRC32::D::calc
- CRC32::Q::calc
- CRC64::ECMA::calc
- CRC64::GO_ISO::calc
- CRC64::WE::calc
- CRC64::XY::calc

Usage Examples

Using the built-in CRC functions

// 1) include "cppcrc.h"
#include "cppcrc.h"
#include <stdio.h>

// 2) use the CRC8/CRC16/CRC32 functions, for example:
int main()
{
    uint8_t data[] = {0x12, 0x5A, 0x23, 0x19, 0x92, 0xF3, 0xDE, 0xC2, 0x5A, 0x1F, 0x91, 0xA3};

    // calculate a checksum:
    uint16_t crc_value = CRC16::CCITT_FALSE::calc(data, sizeof(data));
    printf("crc_value = 0x%04X\n", crc_value);

    // view the lookup table:
    auto &crc_table = CRC16::CCITT_FALSE::table();
    printf("crc_table = {0x%04X", crc_table[0]);
    for (int i = 1; i < 256; i++)
        printf(", 0x%04X", crc_table[i]);
    printf("}\n");
}

Creating Your Own CRC Function

// 1) include "cppcrc.h"
#include "cppcrc.h"
#include <stdio.h>

int main()
{
    // 2) pick some CRC settings (these are just an example)
    using base_type = uint8_t;
    constexpr base_type poly = 0x12;
    constexpr base_type init_value = 0x34;
    constexpr bool reflect_in = true;
    constexpr bool reflect_out = true;
    constexpr base_type Xor_out = 0xFF;

    // 3) create a new CRC type by filling in the CRC parameters
    using your_crc_name = crc_utils::crc<base_type, poly, init_value, reflect_in, reflect_out, Xor_out>;

    // you can use your new CRC type to calculate a checksum
    uint8_t data[] = {0x12, 0x34, 0x56};
    auto calculated_crc = your_crc_name::calc(data, sizeof(data));
    printf("calculated_crc = 0x%02X\n", calculated_crc);

    // and access the underlying lookup table for your CRC function
    auto &crc_table = your_crc_name::table();
}

DarrenLevine/cppcrc

CPP/CRC

Requirements

Features

Usage Examples

Using the built-in CRC functions

Creating Your Own CRC Function