def xor(a, b): #input: two byearrays #output: bytearray of their xor if len(a) > len(b): temp = a a = b b = temp s = [] for i in range(0, len(a)): s.append(a[i] ^ b[i]) for i in range(len(a), len(b)): s.append(b[i]) return s def cribpend(a, crib, loc): #crib is too small; append it with 0's depending on location s = [] for i in range(0, loc): s.append(0) for i in range(0, len(crib)): s.append(crib[i]) for i in range(len(crib) + loc, len(a)): s.append(0) s = s[:len(a)] return s def bit(a): #returns bitstring of integer s = "" while (a != 0): if (a % 2 == 0): s += "0" a /= 2 else: s += "1" a -= 1 a /= 2 while len(s) < 8: s += "0" s = s[::-1] return s def s_to_ints(s): #convert string to integer list ("bytearray") b = [] for i in range(0, len(s)): b.append(ord(s[i])) return b def showbytes(a, crib=0): s = "" chars = [] for i in range(65, 91): chars.append(i) for i in range(97, 123): chars.append(i) for i in range(44, 47): chars.append(i) #return string of bytestring for i in range(0, len(a)): if (a[i] in chars): s += chr(a[i]) elif (a[i] == 0): if (crib == 0): s += "█" if (crib == 1): s += " " elif (a[i] == 32): s += " " else: s += "*" return s import pygame import random import sys from pygame.locals import * is_blue = 1 done = 0 x = 30 y = 30 clock = pygame.time.Clock() p1s = "Seven for the Dwarf-lords in halls of stone." p2s = "In the land of Mordor where the shadows lie." #our byte arrays are just integer lists p1 = s_to_ints(p1s) p2 = s_to_ints(p2s) #generate k = [] for i in range(0, len(p1s)): k.append(random.randint(0, 255)) c1 = xor(p1, k) c2 = xor(p2, k) x = xor(c1, c2) ##print showbytes(p1) ##print showbytes(p2) ##print showbytes(c1) ##print showbytes(c2) ##print showbytes(x) pygame.init() screen = pygame.display.set_mode((800, 700)) screen.fill((255, 255, 255)) pygame.display.flip() r = [] is_cap = 0 is_drag = 0 inputting = 0 loc = 0 towrite = 0 while not done: for event in pygame.event.get(): if event.type == pygame.MOUSEBUTTONDOWN: if (event.pos[0] >= 100 and event.pos[1] >= 390 and event.pos[1] <= 435): is_drag = 1 #start dragging if event.type == pygame.MOUSEMOTION and is_drag == 1: loc = (event.pos[0] - 100) / 15 if (loc < 0): loc = 0 if (loc > 43): loc = 43 if event.type == pygame.MOUSEBUTTONUP: is_drag = 0 if (event.pos[0] >= 100 and event.pos[1] >= 390 and event.pos[1] <= 435): #override the rest; we don't want to change output continue charnum = (event.pos[0] - 100)/15 lineremain = event.pos[1] % 100 linenum = int((event.pos[1] - 90) / 100) charnum = int(charnum) if (charnum >= 0 and charnum <= 43 and (lineremain <= 35 or lineremain >= 90) and linenum >= 0 and linenum <= 4): towrite = 1 else: towrite = 0 if event.type == pygame.KEYDOWN and inputting == 1: if event.key == pygame.K_ESCAPE or event.key == pygame.K_RETURN: inputting = 0 continue elif event.key == pygame.K_LSHIFT or event.key == pygame.K_RSHIFT: is_cap = 1 elif event.key == pygame.K_BACKSPACE and len(r) > 0: if (is_cap == 1): r = r[:-5] else: r = r[:-1] else: try: this_r = int(event.key) if (is_cap == 1): this_r = max(0, this_r - 32) r.append(this_r) except: pass if event.type == pygame.KEYDOWN and inputting == 0: if (event.key == pygame.K_RETURN): inputting = 1 if event.type == pygame.KEYUP and inputting == 1: if event.key == pygame.K_LSHIFT or event.key == pygame.K_RSHIFT: is_cap = 0 if event.type == QUIT: pygame.quit() sys.exit() keys = pygame.key.get_pressed() ## if keys[pygame.K_BACKSPACE] and len(r) > 0 and inputting == 1: ## r = r[:-1] ## clock.tick(15) screen.fill((255, 255, 255)) myfont = pygame.font.SysFont("Arial", 22, bold=True) label = myfont.render("CMPT403 Crib-dragging demo", 1, (0, 0, 0)) screen.blit(label, (15, 15)) myfont = pygame.font.SysFont("Arial", 22, italic=True) label = myfont.render("Ciphertext 1 (C1):", 1, (0, 125, 0)) screen.blit(label, (50, 50)) label = myfont.render("Ciphertext 2 (C2):", 1, (0, 125, 0)) screen.blit(label, (50, 150)) label = myfont.render("Xortext (X = C1 XOR C2):", 1, (0, 125, 0)) screen.blit(label, (50, 250)) label = myfont.render("Crib (R):", 1, (255, 0, 0)) screen.blit(label, (50, 350)) label = myfont.render("Xorcribtext (X XOR R):", 1, (0, 125, 0)) screen.blit(label, (50, 450)) myfont = pygame.font.SysFont("monospace", 25) label = myfont.render(showbytes(c1), 1, (0, 0, 0)) screen.blit(label, (100, 100)) label = myfont.render(showbytes(c2), 1, (0, 0, 0)) screen.blit(label, (100, 200)) label = myfont.render(showbytes(x), 1, (0, 0, 0)) screen.blit(label, (100, 300)) loc = int(loc) rp = cribpend(c1, r, loc) #r, appended label = myfont.render(showbytes(rp, crib=1), 1, (255, 0, 0)) screen.blit(label, (100, 400)) xr = xor(x, rp) label = myfont.render(showbytes(xr), 1, (0, 0, 0)) screen.blit(label, (100, 500)) myfont = pygame.font.SysFont("Arial", 10) for j in range(0, 5): tx = 100 ty = 100 width = 665 height = 25 pygame.draw.polygon(screen, (0, 235, 235), ((tx, ty+j*100), (tx+width, ty+j*100), (tx+width, ty+height+j*100), (tx, ty+height+j*100)), 2) if (inputting == 1): j = 3 pygame.draw.polygon(screen, (255, 0, 0), ((tx, ty+j*100), (tx+width, ty+j*100), (tx+width, ty+height+j*100), (tx, ty+height+j*100)), 2) pygame.draw.line(screen, (255, 0, 0), (100+(loc+len(r))*15, 400), (100+(loc+len(r))*15, 425) ) for j in range(0, 5): for i in range(0, 44): label = myfont.render(str(i), 1, (150, 150, 150)) screen.blit(label, (100 + i * 15 + 4, 80 + j * 100)) if (towrite == 1): vnames = ["C1", "C2", "Xortext", "R", "Xorcribtext"] vname = vnames[linenum] vs = [c1, c2, x, rp, xr] vstr = str(vs[linenum][charnum]) vstr += str(" (" + bit(vs[linenum][charnum]) + ")") myfont = pygame.font.SysFont("Arial", 18) label = myfont.render("Char " + str(charnum) + " of " + vname + ": " + vstr, 1, (0, 0, 0)) screen.blit(label, (100, 600)) if linenum == 2: s = "C1[{}] XOR C2[{}] = {}({}) XOR {}({}) = {}({})".format( charnum, charnum, c1[charnum], bit(c1[charnum]), c2[charnum], bit(c2[charnum]), x[charnum], bit(x[charnum])) label = myfont.render(s, 1, (135, 0, 0)) screen.blit(label, (100, 630)) if linenum == 4: s = "X[{}] XOR R[{}] = {}({}) XOR {}({}) = {}({})".format( charnum, charnum, x[charnum], bit(x[charnum]), rp[charnum], bit(rp[charnum]), xr[charnum], bit(xr[charnum])) label = myfont.render(s, 1, (135, 0, 0)) screen.blit(label, (100, 630)) pygame.display.flip() clock.tick(30)