hacklu-cobol-otp-brute.py

#!/usr/bin/env python3

f = open("out","rb")
data = f.read()
f.close()
state = False
a = []
for c in data:
  if c == 0xd or c == 0xa:
    state = True
    continue
  if state:
    a.append(c)
    # print("%02x" % c)
  
key = []
key.append(a[0] ^ ord('f'))
key.append(a[1] ^ ord('l'))
key.append(a[2] ^ ord('a'))
key.append(a[3] ^ ord('g'))
key.append(a[4] ^ ord('{'))
# key.append(a[5] ^ ord('y'))
key.append(0x2a ^ ord('_'))
key.append(a[6] ^ ord('0'))
# key.append(a[7] ^ ord('u'))
key.append(0x7b ^ ord('h'))
key.append(a[8] ^ ord('_'))
# key.append(a[9] ^ ord('c'))
key.append(0x5f ^ ord('_'))
# key.append(a[10] ^ ord('4'))
# key.append(a[11] ^ ord('n'))
# key.append(a[12] ^ ord('_'))
# key.append(0)
# key.append(0)


out = ""
import string
for i in range(0,len(a)):
  oc =  chr(a[i] ^ key[i % len(key)])
  if oc in string.printable:
    print("XORing %02x with index %d for %c" % (a[i],i % len(key),chr(a[i] ^ key[i % len(key)])))
    out += oc
  else:
    print("XOR nonprintable")
    out += "*"

print(out)
print("")
outhex = ""
for cx in out:
  outhex += "%02x " % ord(cx)
print(outhex)