Embeddable, dependency-free C11 implementation of the SHA-3 cryptographic hash functions, eXtendable Output Functions (XOF), and Hash-based Message Authentication Code functions (HMAC) defined in FIPS 202, SP 800-185, and the draft KangarooTwelve and TurboSHAKE specification.

Includes AVX-512 acceleration, Doxygen-friendly API documentation, and a full test suite with sanitizers enabled and test vectors from the NIST CSRC "Examples With Intermediate Values" site and the Test Vectors section of the draft KangarooTwelve and TurboSHAKE specification.

The following algorithms are implemented:

SHA3-224, SHA3-256, SHA3-384, and SHA3-512: SHA-3 cryptographic hash functions with fixed-length output, as defined in section 6.1 of FIPS 202.
HMAC-SHA3-224, HMAC-SHA3-256, HMAC-SHA3-384, HMAC-SHA3-512: HMAC instantiated with SHA-3 hash functions, as specified in section 7 of FIPS 202, RFC 2104, and FIPS 198-1.
SHAKE128, SHAKE128-XOF, SHAKE256, and SHAKE256-XOF: SHA-3 XOFs with both fixed-length output and arbitrary-length output, as defined in section 6.2 of FIPS 202.
cSHAKE128, cSHAKE128-XOF, cSHAKE256, and cSHAKE256-XOF: Fixed-length and XOF variants of the customizable-SHAKE primitive, as defined in section 3 of SP 800-185.
KMAC128, KMAC128-XOF, KMAC256 and KMAC256-XOF: Keccak Message Authentication Code (MAC), as defined in section 4 of SP 800-185.
TupleHash128, TupleHash128-XOF, TupleHash256, and TupleHash256-XOF: Misuse-resistant hash function and XOF for hashing a tuple of byte strings, as defined in section 5 of SP 800-185.
ParallelHash128, ParallelHash128-XOF, ParallelHash256, and ParallelHash256-XOF: Hash function and XOF, as defined in section 6 of SP 800-185.
TurboSHAKE128 and TurboSHAKE256: Faster, reduced-round XOFs, as defined in the draft KangarooTwelve and TurboSHAKE specification.
KangarooTwelve: Faster, reduced-round XOF with a customzation string, as defined in the draft KangarooTwelve and TurboSHAKE specification.

Use make to build a shared library and minimal sample application, make doc to generate HTML-formatted API documentation, and make test to run the test suite.

Examples

Calculate the SHA3-256 hash of a test string and print the result to standard output:

// sha3-256-example: print sha3-256 hash of data to standard output.
#include <stdint.h>
#include <stdio.h>
#include "hex.h"
#include "sha3.h"
 
// test data
static const uint8_t DATA[] = "this is some test data";
 
int main(void) {
  // hash `DATA` into `buf`
  uint8_t buf[32] = { 0 };
  sha3_256(DATA, sizeof(DATA), buf);
 
  // print result to stdout
  printf("SHA3-256: ");
  hex_write(stdout, buf, sizeof(buf));
  printf("\n");
 
  return 0;
}

Calculate the SHAKE128 hash of a test string and print the first 200 bytes to standard output:

//
// shake128-example: hash contents of DATA with SHAKE128 and print first
// 200 bytes of SHAKE128 hash of data to standard output.
//
#include <stdint.h>
#include <stdio.h>
#include "hex.h"
#include "sha3.h"
 
// test data
static const uint8_t DATA[] = "this is some test data";
 
int main(void) {
  // hash data
  uint8_t buf[200] = { 0 };
  shake128_xof_once(DATA, sizeof(DATA), buf, sizeof(buf));
 
  // print result to stdout
  printf("SHAKE128 (200 bytes): ");
  hex_write(stdout, buf, sizeof(buf));
  printf("\n");
 
  return 0;
}

TurboSHAKE128 example, using the iterative API:

//
// turboshake128-example: Absorb 4096 bytes of data from /dev/urandom in
// 1024 byte chunks, hash it with TurboShake128, then print 128 bytes of
// result in 32 byte chunks (hex-encoded) to standard output.
// output.
//
#include <stdint.h>
#include <stdio.h>
#include <err.h>
#include "hex.h"
#include "sha3.h"
 
int main() {
  // init turboshake
  turboshake_t ts;
  turboshake128_init(&ts);
 
  // open source
  FILE *fh = fopen("/dev/urandom", "rb");
  if (!fh) {
    err(-1, "fopen()");
  }
 
  {
    // read and absorb
    uint8_t buf[1024] = { 0 };
    for (size_t i = 0; i < 4096/sizeof(buf); i++) {
      // read data
      if (!fread(buf, sizeof(buf), 1, fh)) {
        err(-1, "fread()");
      }
 
      // absorb
      turboshake128_absorb(&ts, buf, sizeof(buf));
    }
  }
 
  // close source
  if (!fclose(fh)) {
    warn("fclose()");
  }
 
 
  printf("TurboShake128 output:\n");
  {
    // squeeze in 32 byte chunks, write to stdout
    uint8_t buf[32] = { 0 };
    for (size_t ofs = 0; ofs < 128; ofs += sizeof(buf)) {
      turboshake128_squeeze(&ts, buf, sizeof(buf));
      hex_write(stdout, buf, sizeof(buf));
    }
  }
  printf("\n");
 
  return 0;
}

See the examples/ directory for more examples.

Documentation

Full API documentation is available in the comments of sha3.h. If you have Doxygen installed, you can generate HTML-formatted API documentation by typeing make doc.

Examples

Documentation

References