Function chacha_init

3rd/mimalloc-2.0.9/src/random.c:101–118

}

static void chacha_init(mi_random_ctx_t* ctx, const uint8_t key[32], uint64_t nonce)
{
  // since we only use chacha for randomness (and not encryption) we
  // do not _need_ to read 32-bit values as little endian but we do anyways
  // just for being compatible :-)
  memset(ctx, 0, sizeof(*ctx));
  for (size_t i = 0; i < 4; i++) {
    const uint8_t* sigma = (uint8_t*)"expand 32-byte k";
    ctx->input[i] = read32(sigma,i);
  }
  for (size_t i = 0; i < 8; i++) {
    ctx->input[i + 4] = read32(key,i);
  }
  ctx->input[12] = 0;
  ctx->input[13] = 0;
  ctx->input[14] = (uint32_t)nonce;
  ctx->input[15] = (uint32_t)(nonce >> 32);
}

static void chacha_split(mi_random_ctx_t* ctx, uint64_t nonce, mi_random_ctx_t* ctx_new) {
  memset(ctx_new, 0, sizeof(*ctx_new));