Oct-13-2017, 02:03 PM
So I'm trying to learn python and I came up with an idea for a little program that reads a text file, converts all of the characters into pseudo-random ones, and then creates a key to return it to human readable form. The issue is that, when I decode the message sometimes one character will get decoded incorrectly. So all 'a' characters might show up as '0', or 'M', etc.
import random
import pickle
import copy
"""
Encodes and decodes files
"""
def load(string):
"""
function that converts characters to pseudo-random
characters and creates a key to decipher later.
"""
## APPEND PATH HERE*
## opens file to store converted data in
datafile = open('/your/path/here/data.dep', 'wb')
## oens file to store key in
keyfile = open('/your/path/here/key.dep', 'wb')
## defines some default values
key = []
user_string = []
working_pool = {}
out_key = {}
new_string = []
## character map, gets copied to create character pools
all_char = ['a', 'b', 'c', 'd', 'e',
'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y',
'z', 'A', 'B', 'C', 'D',
'E', 'F', 'G', 'H', 'I',
'J', 'K', 'L', 'M', 'N',
'O', 'P', 'Q', 'R', 'S',
'T', 'U', 'V', 'W', 'X',
'Y', 'Z', '0', '1', '2',
'3', '4', '5', '6', '7',
'8', '9', '!', '@', '#',
'$', '%', '^', '&', '*',
'+', '-', '_', '=', '~',
' ', '.', ',', ';', '(',
')', '<', '>', '?', ':',
'|', '/', '~', '[', ']',
'{', '}', '\'', '"', '\t',
'\n', '\\']
## above list copied
char_copy = copy.deepcopy(all_char)
pool = copy.deepcopy(all_char)
## for each character in the character map,
for char in char_copy[:]:
## pick a random character from pool
temp_char = random.choice(pool)
## appends working_pool dictionary
## {'random': 'actual'} EXAMPLE
working_pool[temp_char] = char
## appends my_key dictionary, creates key
## {'actual': 'random'} EXAMPLE
out_key[char] = temp_char
## remove the random character assigned
## from the pool so it cant be picked twice
pool.remove(temp_char)
## opens user defined file supplied by function parameter
with open(string) as infile:
## while true, examine each character
while True:
## append 'user_string' with each character in file
ch = infile.read(1)
user_string.append(ch)
## if the character is in the conversion pool
if ch in working_pool:
## convert character
new_string.append(working_pool[ch])
else:
## keep character as is
new_string.append(ch)
## repeat until EOF
if not ch:
eof = 'true'
break
## start DEBUG
#test = ''.join(str(z) for z in new_string)
#ustring = ''.join(str(y) for y in user_string)
#print(test)
#print('\n')
#print(ustring)
#print(working_pool)
## end DEBUG
## serializes converted string and stores it
pickle.dump(new_string, datafile)
pickle.dump(out_key, keyfile)
datafile.close()
keyfile.close()
def unload(data, key):
"""
function that, given the correct keyfile,
will translate converted string to human
readable clear text
"""
## opens files supplies by function parameter
input_file = open(data, 'rb')
decoder = open(key, 'rb')
active = True
## while active is true
while active:
try:
## dump data into 'contents' until EOF
contents = pickle.load(input_file)
except EOFError:
## if EOF, active is false
active = False
## same as above but for decoder
active = True
while active:
try:
load_key = pickle.load(decoder)
except EOFError:
active = False
## sets empty list for converting
converted_string = []
## for each value in the encrypted data,
for ch in contents[:]:
## if the value is in the key,
if ch in load_key:
## add the decoded character to converted_string
converted_string.append(load_key[ch])
#else:
#converted_string.append(ch)
clear_text = ''.join(str(e) for e in converted_string)
## start DEBUG
#print('\n')
#print(load_key)
## end DEBUG
## print unencrypted results
print(clear_text)
input_file.close()
decoder.close()
## CALL FUNCTIONS HERE
load('/fake/data/someFile.txt')
unload('/your/path/here/data.dep', '/foo/bar/key.dep')any help or general python advice is greatly appreciated :)