Function simplicity_read_sha256_context

src/simplicity/frame.c:152–162

Read data from a Simplicity CTX8 type (TWO^8)^<2^64 * TWO^64 * TWO^256 and fill in a sha256_context value. * Advance the 'src' frame to the end of the CTX8 type. * Returns false if the context's counter is too large (i.e. the compression count is greater than or equal to 2^55). * * The notation X^<2 is notation for the type (S X) * The notation X^<(2*n) is notation for the type S (X^n) * X^<n

 *               '*src' is a valid read frame for 838 more cells;
 */
bool simplicity_read_sha256_context(sha256_context* ctx, frameItem* src) {
  size_t len;
  uint_fast64_t compressionCount;

  simplicity_read_buffer8(ctx->block, &len, src, 5);
  compressionCount = simplicity_read64(src);
  ctx->counter = ((compressionCount*1U) << 6) + len;
  read32s(ctx->output, 8, src);
  ctx->overflow = (sha256_max_counter >> 6) <= compressionCount;
  return !ctx->overflow;
}

/* Write data to a Simplicity CTX8 type (TWO^8)^<2^64 * TWO^64 * TWO^256 from a sha256_context value.
 * Advance the 'dst' frame to the end of the CTX8 type.