hash_hunt.py

hash_hunt.py

def check_hash(h):
    data = bytes.fromhex(h) + 32 * b'\x00'
    offset = 0

    # 1.
    if data[offset] < 0xc0:
        offset += 1
    
    # 2.
    if data[offset] < 0xc0:
        return False
    offset += get_offset(data[offset])

    # 3.
    for _ in range(3):
        offset += get_length(data[offset:])
        if offset > 27:
            return False
    
    # 4.
    log_len = get_length(data[offset:])
    if data[offset] < 0xf9 or log_len < 0x800:
        return False
    offset += get_offset(data[offset])
    if offset > 30:
        return False
    
    # 5.
    if data[offset] < 0xb9 or (data[offset] >= 0xc0 and data[offset] < 0xf9):
        return False
    buffer_len = get_length(data[offset:])
    if buffer_len > (log_len - 3) or buffer_len < 0x800 or buffer_len > 0xfffff:
        return False

    return True