DEFCON 29 Badge Signer

dc29_badge_signer.py

#!/usr/bin/env python3
import argparse
import random
import sys

def gen_key():
    random.seed()
    key = ""
    for idx in range(32):
        key += hex(random.randrange(0, 16)).upper()[-1]
    return key

def sign_key(request, signer, signer_type, with_signal):
    random_buf = gen_key()
    response  = random_buf[0:2]
    response += request[2:4]
    response += signer[2:4]
    response += signer[8:10]
    response += request[8:10]
    response += signer[16:18]
    response += random_buf[12:14]
    response += signer[18:20]
    response += request[16:20]
    response += "13"
    response += random_buf[22:24]
    response += f'{signer_type:#04X}'[2:]
    response += random_buf[26:28]
    if not with_signal:
        response += "01"
    else:
        response += "7F"
    response += random_buf[30:32]
    return response

def parse():
    parser = argparse.ArgumentParser()
    parser.add_argument("request_code")
    parser.add_argument("signer_type", help="Type of badge being used to sign the request. "
            "Valid values are: HUMAN, GOON, CREATOR, SPEAKER, ARTIST, VENDOR, PRESS")
    parser.add_argument("-s", "--with-signal", action="store_true", help="Sets that the signer has the signal")
    return parser.parse_args()


def main():
    args = parse()
    stype = 0x1
    if args.signer_type.lower() == "human":
        stype = 0x1 << 0
    elif args.signer_type.lower() == "goon":
        stype = 0x1 << 1
    elif args.signer_type.lower() == "creator":
        stype = 0x1 << 2
    elif args.signer_type.lower() == "speaker":
        stype = 0x1 << 3
    elif args.signer_type.lower() == "artist":
        stype = 0x1 << 4
    elif args.signer_type.lower() == "vendor":
        stype = 0x1 << 5
    elif args.signer_type.lower() == "press":
        stype = 0x1 << 6
    else:
        print(f"Invalid signer type {args.signer_type}")
        return 1

    signer_key = gen_key()
    print(f"Signing request {args.request_code} with the "
          f"{args.signer_type.lower()} badge {signer_key}")
    result = sign_key(args.request_code, signer_key, stype, args.with_signal)
    print(result)
    return 0

if __name__ == "__main__":
    sys.exit(main())