commit 91a6a632a86792011118268f71bee32393440961 Author: Ben Goldsworthy Date: Tue Jun 23 23:27:01 2020 +0100 Initial commit diff --git a/LICENSE b/LICENSE new file mode 100755 index 0000000..78df873 --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. 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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/src/Pypher.py b/src/Pypher.py new file mode 100755 index 0000000..654a563 --- /dev/null +++ b/src/Pypher.py @@ -0,0 +1,251 @@ +''' + 6-Letter Pypher 1.0 + Copyright (c) 2015 Ben Goldsworthy (rumps) + + A program to encode and decode text using a 6-letter cipher and given + keyword. + + 6-Letter Pypher is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + 6-Letter Pypher is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with 6-Letter Pypher. If not, see . +''' + +import numpy as np +import string +import random +import re +import pickle +import operator + +# A dictionary used for indexing characters in the initial alphanumeric grid +alphaNumCoords = {0: 'A', 1: 'B', 2: 'C', 3: 'D', 4: 'E', 5: 'F'} + +def encodePlaintext(): + """Coordinates the steps involved in encoding plaintext and prints results.""" + fileName = genFileName(4) + alphaNumGrid = makeAlphaNumGrid(fileName) + + plaintext = enterPlaintext() + keyword = sorted(enterKeyword(len(plaintext))) + print "\nEncoding", plaintext, "with keyword", getKeywordString(keyword), "...\n" + print "--Alphanumeric grid--\n", alphaNumGrid + + ciphertext = getTransitionalCiphertext(plaintext, alphaNumGrid) + print "Transitional ciphertext:", ciphertext, "\n" + + keywordGrid = getKeywordGrid(ciphertext, keyword, 'encode') + print "--Keyword grid--\n", keywordGrid + ciphertext = getCiphertext(keywordGrid) + print "Final ciphertext:", ciphertext, "\nEncoded using grid", fileName +def decodeCiphertext(): + """Coordinates the steps involved in decoding ciphertext and prints results.""" + filename = raw_input("Enter grid code: ") + alphaNumGrid = pickle.load(open("Ciphers/"+filename+".p", "rb" )) + + ciphertext = enterCiphertext() + keyword = enterKeyword(len(ciphertext)/2) + keywordGrid = getKeywordGrid(ciphertext, keyword, 'decode') + print "\nDecoding", ciphertext, "with keyword", getKeywordString(keyword), "using grid", filename, "...\n" + print "--Keyword grid--\n", keywordGrid + + plaintext = getTransitionalPlaintext(keywordGrid) + print "Transitional plaintext:", plaintext, "\n" + + print "--Alphanumeric grid--\n", alphaNumGrid + plaintext = getPlaintext(plaintext, alphaNumGrid) + print "Final plaintext:", plaintext +def showCredits(): + """Prints the credits and copyright information.""" + print "*" * 80 + print "\t\t\t6-Letter Pypher 1.0" + print "\t\tCopyright (c) 2015 Ben Goldsworthy (rumps)\n" + print " A program to encode and decode text using a 6-letter cipher and given\n keyword.\n " + print " 6-Letter Pypher is free software: you can redistribute it and/or modify\n it under the terms of the GNU General Public License as published by\n the Free Software Foundation, either version 3 of the License, or\n (at your option) any later version.\n " + print " 6-Letter Pypher is distributed in the hope that it will be useful,\n but WITHOUT ANY WARRANTY; without even the implied warranty of\n MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\n GNU General Public License for more details.\n " + print " You should have received a copy of the GNU General Public License\n along with 6-Letter Pypher. If not, see ." + print "*" * 80 + +def makeAlphaNumGrid(fileName): + """Generates an alphanumeric grid and pickles it for later consumption.""" + vals = list(string.ascii_uppercase + string.digits) + random.shuffle(vals) + grid = np.array(vals).reshape(6,6) + pickle.dump(grid, open("Ciphers/"+fileName+".p", "wb")) + return grid +def genFileName(n): + """Generates a randomised filename for the pickle.""" + name = "" + for x in range(n): name += random.choice(string.letters + string.digits) + return name +def findLetter(letter, x): + """Finds a letter in the alphanumeric grid and returns its coordinates.""" + for i in range(6): + for j in range(6): + if x[i][j] == letter: + return alphaNumCoords[j] + alphaNumCoords[i] + return '' + +def enterPlaintext(): + """Takes and validates plaintext entry from the user. Returns valid entry + stripped of whitespace. + """ + plaintext = "" + # RegEx for non-alphanumeric characters + alphaNum = re.compile(r'[^a-zA-Z0-9 ]') + + while plaintext == "": + err = False + plaintext = raw_input("What is your plaintext? ").upper() + if alphaNum.search(plaintext) != None: + print "ERR: Plaintext must contain characters A-Z or 0-9" + err = True + if err == True: plaintext = "" + # Includes RegEx to strip whitespace + return re.sub(r'\W+', '', plaintext) +def enterKeyword(plaintextLen): + """Takes and validates keyword entry from the user. Returns an list of + indexed tuples representing the keyword string. + """ + keyword = "" + # RegEx for detecting repeated or invalid characters + rpt = re.compile(r'.*(.).*\1.*') + alpha = re.compile(r'[^a-zA-Z]') + + while keyword == "": + err = False + keyword = raw_input("What is the keyword? ").upper() + if alpha.search(keyword) != None: + print "ERR: Keyword must contain characters A-Z" + err = True + if rpt.match(keyword): + print "ERR: Keyword must contain no repeating characters" + err = True + if plaintextLen % len(keyword) != 0: + print "ERR: Length of plaintext (", plaintextLen, \ + ") must be divisible by length of keyword (", len(keyword), ")" + err = True + if err == True: keyword = "" + return getKeyword(keyword) +def enterCiphertext(): + """Takes and validates ciphertext entry from the user.""" + ciphertext = "" + # RegEx to detect invalid characters + alphaNum = re.compile(r'[^A-F]') + + while ciphertext == "": + err = False + ciphertext = raw_input("Enter ciphertext: ").upper() + if alphaNum.search(ciphertext) != None: + print "ERR: Ciphertext must contain characters A-F" + err = True + if err == True: ciphertext = "" + return ciphertext + +def getKeyword(keyword): + """Returns a sorted list of tuples representing the keyword string.""" + return sorted(enumerate(keyword), key=operator.itemgetter(1)) +def getKeywordGrid(ciphertext, keyword, mode): + """Generates the keyword grid from the entered keyword, then returns it + sorted appropriately (either alphabetically for encoding or back to keywordly + for decoding). + """ + keywordCipher = [x[1] for x in keyword] + keywordLength = len(keywordCipher) + for letter in ciphertext: + keywordCipher.append(letter) + + yLength = len(ciphertext)/keywordLength + 1 + keywordGrid = np.array(keywordCipher).reshape(yLength, keywordLength) + + if mode == 'encode': + return keywordGrid[:, np.array(orderKeyword([x[1] for x in keyword]))] + elif mode == 'decode': + return keywordGrid[:, np.array([x[1] for x in getUnorderedKeyword(keyword)])] +def orderKeyword(keyword): + """Orders the keyword characters alphabetically and returns the new + indicies. + """ + orderedKeyword = sorted(enumerate(keyword), key=operator.itemgetter(1)) + return [x[0] for x in orderedKeyword] +def getUnorderedKeyword(keyword): + originalKeyword = sorted(keyword) + currIndex = 0 + mylist = [] + for i in range(len(getKeywordString(keyword))): + mylist.append((keyword[i][0], originalKeyword[i][0])) + return sorted(mylist) + +def getKeywordString(keyword): + """Extracts the keyword string from the list of tuples representing it.""" + keywordString = "" + for x in sorted(keyword): keywordString += x[1] + return keywordString +def getTransitionalCiphertext(plaintext, alphaNumGrid): + """Gets the ciphertext created by applying the alphanumeric grid to the + entered plaintext. + """ + ciphertext = "" + for letter in plaintext: + ciphertext += findLetter(letter, alphaNumGrid) + return ciphertext +def getCiphertext(keywordGrid): + """Gets the final ciphertext created by applying the keyword grid to the + transitional ciphertext. + """ + ciphertext = "" + for row in keywordGrid[1:].tolist(): + for letter in row: + ciphertext += letter + return ciphertext +def getTransitionalPlaintext(keywordGrid): + """Splits the transitional plaintext into 2-character chunks.""" + tpt = "" + double = 0 + for x in keywordGrid[1:]: + for x in x: + if double == 2: + double = 0 + tpt += " " + tpt += x + double += 1 + return tpt +def getPlaintext(plaintext, alphaNumGrid): + """Gets the final plaintext created by reversing the application of the + alphanumeric grid to the original plaintext. + """ + finalPlaintext = "" + for x in plaintext.split(): + for k,v in alphaNumCoords.iteritems(): + if v == x[1]: xcoord = k + if v == x[0]: ycoord = k + finalPlaintext += alphaNumGrid[xcoord][ycoord] + return finalPlaintext + +def menu(): + """Displays the option menu for the user and takes input.""" + option = '' + while option != 4: + print "\nSelect action:" + print "\t1. Encode plaintext" + print "\t2. Decode plaintext" + print "\t3. License & Credits" + print "\t4. Exit\n" + option = raw_input("Choice: ") + if option == '1': + encodePlaintext() + elif option == '2': + decodeCiphertext() + elif option == '3': + showCredits() + +# Calls the menu on program start +menu()