// test_main.c
// Self test Modules for BLAKE2b and BLAKE2s -- and a stub main().

#include "blake2s.h"
#include <assert.h>
#include <stdio.h>

_Static_assert(sizeof(struct BLAKE2s_param) == (8 * sizeof(uint32_t)), "sizeof struct BLAKE2s_param");

// Deterministic sequences (Fibonacci generator).
static void
selftest_seq(uint8_t *out, size_t len, uint32_t seed)
{
  size_t i;
  uint32_t t, a, b;

  a = 0xDEAD4BAD * seed; // prime
  b = 1;

  for (i = 0; i < len; i++) { // fill the buf
    t = a + b;
    a = b;
    b = t;
    out[i] = (t >> 24) & 0xFF;
  }
}

// BLAKE2s self-test validation. Return 0 when OK.
int
blake2s_selftest()
{
  // Grand hash of hash results.
  const uint8_t blake2s_res[32] = {0x6A, 0x41, 0x1F, 0x08, 0xCE, 0x25, 0xAD, 0xCD, 0xFB, 0x02, 0xAB,
                                   0xA6, 0x41, 0x45, 0x1C, 0xEC, 0x53, 0xC5, 0x98, 0xB2, 0x4F, 0x4F,
                                   0xC7, 0x87, 0xFB, 0xDC, 0x88, 0x79, 0x7F, 0x4C, 0x1D, 0xFE};
  // Parameter sets.
  const size_t b2s_md_len[4] = {16, 20, 28, 32};
  const size_t b2s_in_len[6] = {0, 3, 64, 65, 255, 1024};

  size_t i, j, outlen, inlen;
  uint8_t in[1024], md[32], key[32];
  struct BLAKE2s_ctx ctx;

  // 256-bit hash for testing.
  if (BLAKE2s_init(&ctx, 32, NULL, 0)) return -1;

  for (i = 0; i < 4; i++) {
    outlen = b2s_md_len[i];
    for (j = 0; j < 6; j++) {
      inlen = b2s_in_len[j];

      selftest_seq(in, inlen, inlen); // unkeyed hash
      BLAKE2s(md, outlen, NULL, 0, in, inlen);
      BLAKE2s_update(&ctx, md, outlen); // hash the hash

      selftest_seq(key, outlen, outlen); // keyed hash
      BLAKE2s(md, outlen, key, outlen, in, inlen);
      BLAKE2s_update(&ctx, md, outlen); // hash the hash
    }
  }

  // Compute and compare the hash of hashes.
  BLAKE2s_final(&ctx, md);
  for (i = 0; i < 32; i++) {
    if (md[i] != blake2s_res[i]) return -1;
  }

  return 0;
}

int
main(void)
{
  // functions
  assert(rotr_u32(0xdecafade, 16) == 0xfadedeca);
  assert(rotr_u32(0xdecafade, 8) == 0xdedecafa);

  const int good = blake2s_selftest();
  printf("blake2s_selftest() = %s\n", good ? "FAIL" : "OK");

  char *in = "abc";
  size_t inlen = 3;

  uint8_t out[32];
  BLAKE2s(out, 32, NULL, 0, in, inlen);

  const uint8_t blake2s_res[32] = {0x50, 0x8C, 0x5E, 0x8C, 0x32, 0x7C, 0x14, 0xE2, 0xE1, 0xA7, 0x2B,
                                   0xA3, 0x4E, 0xEB, 0x45, 0x2F, 0x37, 0x45, 0x8B, 0x20, 0x9E, 0xD6,
                                   0x3A, 0x29, 0x4D, 0x99, 0x9B, 0x4C, 0x86, 0x67, 0x59, 0x82};

  for (unsigned i = 0; i < 32; i++) {
    if (out[i] != blake2s_res[i]) {
      printf("digest failed");
      printf("\nout: ");
      for (unsigned n = 0; n < 32; ++n) printf(" %02x", out[n]);
      printf("\nres: ");
      for (unsigned n = 0; n < 32; ++n) printf(" %02x", blake2s_res[n]);
      return -1;
    }
  }
  return good;
}