rhasheq

Strict C89 LibRHash file checksum verification library with NO_DISCARD enum error percolation, Safe CRT support, and optional single-header STB-style amalgamation.

Originally the librhash implementation of libacquire's checksum API.

Features

• Strict ISO C89 / ANSI C compatibility: Compiles cleanly with -std=c89 -pedantic -Wall -Wextra -Werror on GCC/Clang and /W4 /WX on MSVC.
• Explicit Error Percolation: Every function returns a NO_DISCARD rhasheq_error_t status code (RHASHEQ_SUCCESS, RHASHEQ_INVALID_ARGUMENT, RHASHEQ_OUT_OF_MEMORY, RHASHEQ_INIT_ERROR, RHASHEQ_HASH_ERROR, RHASHEQ_FORMAT_ERROR) and writes verification results to an output bool *.
• Flexible Build Modes:
  • Static library (-DRHASHEQ_BUILD_STATIC=ON, default)
  • Shared library (-DRHASHEQ_BUILD_SHARED=ON)
  • Header-only INTERFACE library (-DRHASHEQ_HEADER_ONLY=ON)
  • Single-header STB-style amalgamation (-DRHASHEQ_BUILD_AMALGAMATION=ON, generates rhasheq_amalgamation.h; define RHASHEQ_IMPLEMENTATION before including in one translation unit)
• 31 Hash Algorithms Supported: crc32, crc32c, md4, md5, sha1, sha224, sha256, sha384, sha512, sha3_224, sha3_256, sha3_384, sha3_512, tiger, tth, btih, ed2k, aich, whirlpool, ripemd160, gost94, gost94_cryptopro, has160, gost12_256, gost12_512, edonr256, edonr512, snefru128, snefru256, blake2s, blake2b.

Dependencies

• CMake (3.14 or later, including CMake 4.x)
• C compiler (any C89-compatible compiler supported by CMake)
• LibRHash (resolved automatically via system packages/vcpkg or fetched via CMake FetchContent)
• c89stringutils (resolved automatically via vcpkg/system packages or fetched via CMake FetchContent)

Build & Test

cmake -S . -B build
cmake --build build
ctest --test-dir build --output-on-failure

CMake Options

Option	Default	Description
RHASHEQ_BUILD_STATIC	ON	Build rhasheq as a static library
RHASHEQ_BUILD_SHARED	OFF	Build rhasheq as a shared library
RHASHEQ_HEADER_ONLY	OFF	Use rhasheq as a header-only INTERFACE library
RHASHEQ_BUILD_AMALGAMATION	ON	Generate single-file rhasheq_amalgamation.h in the build directory
RHASHEQ_BUILD_TESTING / BUILD_TESTING	ON	Build unit and amalgamation tests
RHASHEQ_LTO	OFF	Enable Link-Time Optimization (IPO/LTO)
RHASHEQ_CHARSET	Unicode	Character set (Unicode or ANSI)
RHASHEQ_THREADING	Multi-threaded	Threading mode (Multi-threaded or Single-threaded)
RHASHEQ_CRT_LINKAGE	Shared	MSVC CRT linkage (Shared or Static)

Usage

Linked Library

#include <stdio.h>
#include <rhasheq.h>

int main(void) {
  bool is_match = false;
  rhasheq_error_t rc;

  rc = sha256("path/to/file.txt",
              "1292593d95c35eeccc89ffa1c91d6fe53b49f81cbf2c2b7758842b7f3186fcc2",
              &is_match);
  if (rc != RHASHEQ_SUCCESS) {
    return (int)rc;
  }

  printf("SHA-256 matches: %s\n", is_match ? "true" : "false");
  return 0;
}

Header-Only / Amalgamation

Define RHASHEQ_IMPLEMENTATION in one .c file before including rhasheq.h (or the generated rhasheq_amalgamation.h):

#define RHASHEQ_IMPLEMENTATION
#include "rhasheq_amalgamation.h"

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License

The code is distributed under BSD Zero Clause License.