Function padding

bitvm/src/hash/sha256_u4.rs:69–104

(num_bytes: u32)

}

pub fn padding(num_bytes: u32) -> (Script, u32) {
    let l = (num_bytes * 8) as i32;
    let mut k = 512 - l - 8 - 32; // heres is usually minus 8, but as
                                  // there will be never that many bytes to process
                                  // one u32 will be enough
    let mut chunks = 1;
    while k < 0 {
        k += 512;
        chunks += 1;
    }
    let zeros = k / 16;
    let extras = k % 16;

    (
        script! {
          8
          0
          for i in 0..zeros {
              if i == 0 {
                  0
                  OP_DUP
                  OP_2DUP
              } else {
                  OP_2DUP
                  OP_2DUP
              }
          }
          if extras > 0 {
              0
              0
          }
          { u4_number_to_nibble( l as u32 ) }
        },
        chunks,
    )
}

pub fn calculate_s_part_1(
    offset_number: u32,