Function simplicity_tapdata_init

src/simplicity/jets.c:1408–1425

simplicity_tapdata_init : ONE |- CTX8 */

/* simplicity_tapdata_init : ONE |- CTX8 */
bool simplicity_tapdata_init(frameItem* dst, frameItem src, const txEnv* env) {
  (void) env; /* env is unused. */
  (void) src; /* env is unused. */

  sha256_midstate tapleafTag;
  {
    static const unsigned char tagName[] = "TapData";
    sha256_context ctx = sha256_init(tapleafTag.s);
    sha256_uchars(&ctx, tagName, sizeof(tagName) - 1);
    sha256_finalize(&ctx);
  }
  uint32_t iv[8];
  sha256_context ctx = sha256_init(iv);
  sha256_hash(&ctx, &tapleafTag);
  sha256_hash(&ctx, &tapleafTag);

  return simplicity_write_sha256_context(dst, &ctx);
}