Function simplicity_nonce_hash

src/simplicity/elements/elementsJets.c:951–983

nonce_hash : CTX8 * S (Conf TWO^256) |- CTX8 */

/* nonce_hash : CTX8 * S (Conf TWO^256) |- CTX8 */
bool simplicity_nonce_hash(frameItem* dst, frameItem src, const txEnv* env) {
  (void) env; // env is unused.
  sha256_midstate midstate;
  unsigned char buf[32];
  sha256_context ctx = {.output = midstate.s};

  /* Read a SHA-256 context. */
  if (!simplicity_read_sha256_context(&ctx, &src)) return false;

  /* Read an optional nonce. (259 bits) */
  if (readBit(&src)) {
    /* Read a nonce prefix. (2 bits) */
    if (readBit(&src)) {
      /* Read an explicit none prefix. (1 bit) */
      forwardBits(&src, 1);
      sha256_uchar(&ctx, 0x01);
    } else {
      /* Read a confidential none prefix. (1 bit) */
      if (readBit(&src)) {
        sha256_uchar(&ctx, 0x03);
      } else {
        sha256_uchar(&ctx, 0x02);
      }
    }
    /* Read a nonce id body (both confidential and explicit nonce bodies are the same size). (256 bits) */
    read8s(buf, 32, &src);
    sha256_uchars(&ctx, buf, 32);
  } else {
    sha256_uchar(&ctx, 0x00);
  }

  return simplicity_write_sha256_context(dst, &ctx);
}

/* annex_hash : CTX8 * S TWO^256 |- CTX8 */
bool simplicity_annex_hash(frameItem* dst, frameItem src, const txEnv* env) {