HideLog.py

"""" Hides private data from Kresus logs.
     Usage: $python HideLog.py  log_input.json log_output.json. """
     
from sys import argv
import json
from Crypto.Cipher import AES

# -- LABELS
BA = "bankAccount"
TL = "title"
RW = "raw"
AM = "amount"
AN = "accountNumber"
INA = "initialAmount"
LG = "login"
MAX_INT = 1000000000 # avoid possible overflow in Kresus

# -- CRYPTO
# this is BAD crypto (cst. IV, ECB instead of CBC, etc.
# but we need deterministic encryption)
# ==================================================
#                  MODIFY THIS  
key = '123456789abcdefg' 
# ==================================================
encryptor = AES.new(key, AES.MODE_ECB)

def hide(s):
    """ Hides [s] deterministically."""
    # deal with integer/float
    if type(s) == type(0) or type(s) == type(1.2):
        s = str(s)
    # padding
    s = s.encode('ascii', 'ignore')
    length = 16 - (len(s) % 16)
    s += '0'*length
    encS = hash(encryptor.encrypt(s))
    if type(s) == type(0):     # deal with integer
        encS = int(encS)
    else:                      # deal with string
        encS = str(abs(int(encS)))
    return(encS)

def hideData(data):
    """ Hides private data in any export of Kresus. """
    for op in data["operations"]:
        op[BA] = hide(op[BA])
        op[TL] = hide(op[TL])
        op[RW] = hide(op[RW])
        op[AM] = int(hide(op[AM])) % MAX_INT
    for acc in data["accounts"]:
        acc[AN] = hide(acc[AN])
        acc[TL] = hide(acc[TL])
        acc[INA] = int(hide(acc[INA])) % MAX_INT
    for access in data["accesses"]:
        access[LG] = hide(access[LG])
    for cat in data["categories"]:
        cat[TL] = hide(cat[TL])
    return(data)


def replace(in_name, out_name):
    """ Reads in_name, hides privatde data and dump in out_name. """
    with open(in_name, 'r+') as f_in:
        data = json.load(f_in)
        data_out = hideData(data)
        with open(out_name, 'w') as f_out:
            json.dump(data_out, f_out, indent=4)

in_name = argv[1]
out_name = argv[2]
replace(in_name,out_name)