#!/bin/python3 import base64 import re from Crypto.Util.asn1 import DerSequence from Crypto.Util.asn1 import DerObjectId # DER DATATYPE = "02" LENGTH = "8" ASN1_HEADER_INT = re.compile(DATATYPE + LENGTH) def parse_value(decoded_lines): header_start_posisitons = [ pos.start() for pos in ASN1_HEADER_INT.finditer(decoded_lines) ] for header_start_posisiton in header_start_posisitons: # After 028 the next 4 bit determin the number of bytes num_bytes_position = header_start_posisiton + 3 num_bytes = int(decoded_lines[num_bytes_position], 16) # now we can parse the size using the previously gathered information size_start = header_start_posisiton + 4 size_end = header_start_posisiton + 4 + (num_bytes * 2) print(decoded_lines[size_start: size_end]) # Parse the size of the parsed_size = int(str(decoded_lines[size_start: size_end]), 16) parsed_content = decoded_lines[ size_end: size_end + (parsed_size * 2) ] print(parsed_content) def main() -> int: with open("../2048_key.priv", "r") as key_file: filecontent_lines = key_file.readlines() decoded_lines = "" for line in filecontent_lines: if line.startswith("-----"): continue if line.strip() == "": print("?"*96) else: decoded_line = base64.b64decode(line).hex() print(decoded_line) decoded_lines += decoded_line # parse_value(decoded_lines) return 0 if __name__ == "__main__": raise SystemExit(main())