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kuroshan1104

Algortimo DES

kuroshan1104
Jul 21st, 2021
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  1. # Conversión hexadecimal a binaria
  2. def hexAbin(s):
  3.     mp = {'0': "0000",
  4.           '1': "0001",
  5.           '2': "0010",
  6.           '3': "0011",
  7.           '4': "0100",
  8.           '5': "0101",
  9.           '6': "0110",
  10.           '7': "0111",
  11.           '8': "1000",
  12.           '9': "1001",
  13.           'A': "1010",
  14.           'B': "1011",
  15.           'C': "1100",
  16.           'D': "1101",
  17.           'E': "1110",
  18.           'F': "1111"}
  19.     bin = ""
  20.     for i in range(len(s)):
  21.         bin = bin + mp[s[i]]
  22.     return bin
  23.  
  24.  
  25. # Conversión binaria a hexadecimal
  26. def binAhex(s):
  27.     mp = {"0000": '0',
  28.           "0001": '1',
  29.           "0010": '2',
  30.           "0011": '3',
  31.           "0100": '4',
  32.           "0101": '5',
  33.           "0110": '6',
  34.           "0111": '7',
  35.           "1000": '8',
  36.           "1001": '9',
  37.           "1010": 'A',
  38.           "1011": 'B',
  39.           "1100": 'C',
  40.           "1101": 'D',
  41.           "1110": 'E',
  42.           "1111": 'F'}
  43.     hex = ""
  44.     for i in range(0, len(s), 4):
  45.         ch = ""
  46.         ch = ch + s[i]
  47.         ch = ch + s[i + 1]
  48.         ch = ch + s[i + 2]
  49.         ch = ch + s[i + 3]
  50.         hex = hex + mp[ch]
  51.  
  52.     return hex
  53.  
  54.  
  55. # Conversión de binario a decimal
  56. def binAdec(binary):
  57.     binary1 = binary
  58.     decimal, i, n = 0, 0, 0
  59.     while (binary != 0):
  60.         dec = binary % 10
  61.         decimal = decimal + dec * pow(2, i)
  62.         binary = binary // 10
  63.         i += 1
  64.     return decimal
  65.  
  66.  
  67. # Conversión decimal a binaria
  68. def decAbin(num):
  69.     res = bin(num).replace("0b", "")
  70.     if (len(res) % 4 != 0):
  71.         div = len(res) / 4
  72.         div = int(div)
  73.         counter = (4 * (div + 1)) - len(res)
  74.         for i in range(0, counter):
  75.             res = '0' + res
  76.     return res
  77.  
  78.  
  79. # Función de permutar para reorganizar los bits
  80. def permute(k, arr, n):
  81.     permutation = ""
  82.     for i in range(0, n):
  83.         permutation = permutation + k[arr[i] - 1]
  84.     return permutation
  85.  
  86.  
  87. # desplazando los bits hacia la izquierda en n-ésimo cambio
  88. def shift_left(k, nth_shifts):
  89.     s = ""
  90.     for i in range(nth_shifts):
  91.         for j in range(1, len(k)):
  92.             s = s + k[j]
  93.         s = s + k[0]
  94.         k = s
  95.         s = ""
  96.     return k
  97.  
  98.  
  99. # calcular el xow de dos cadenas de números binarios ayb
  100. def xor(a, b):
  101.     ans = ""
  102.     for i in range(len(a)):
  103.         if a[i] == b[i]:
  104.             ans = ans + "0"
  105.         else:
  106.             ans = ans + "1"
  107.     return ans
  108.  
  109.  
  110. # Tabla de Posición de 64 bits a nivel inicial: Tabla de Permutación Inicial
  111. initial_perm = [58, 50, 42, 34, 26, 18, 10, 2,
  112.                 60, 52, 44, 36, 28, 20, 12, 4,
  113.                 62, 54, 46, 38, 30, 22, 14, 6,
  114.                 64, 56, 48, 40, 32, 24, 16, 8,
  115.                 57, 49, 41, 33, 25, 17, 9, 1,
  116.                 59, 51, 43, 35, 27, 19, 11, 3,
  117.                 61, 53, 45, 37, 29, 21, 13, 5,
  118.                 63, 55, 47, 39, 31, 23, 15, 7]
  119.  
  120. # Mesa de expansión D-box
  121. exp_d = [32, 1, 2, 3, 4, 5, 4, 5,
  122.          6, 7, 8, 9, 8, 9, 10, 11,
  123.          12, 13, 12, 13, 14, 15, 16, 17,
  124.          16, 17, 18, 19, 20, 21, 20, 21,
  125.          22, 23, 24, 25, 24, 25, 26, 27,
  126.          28, 29, 28, 29, 30, 31, 32, 1]
  127.  
  128. # Tabla de permutación
  129. per = [16, 7, 20, 21,
  130.        29, 12, 28, 17,
  131.        1, 15, 23, 26,
  132.        5, 18, 31, 10,
  133.        2, 8, 24, 14,
  134.        32, 27, 3, 9,
  135.        19, 13, 30, 6,
  136.        22, 11, 4, 25]
  137.  
  138. # Tabla S-box
  139. sbox = [[[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
  140.          [0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
  141.          [4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
  142.          [15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]],
  143.  
  144.         [[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
  145.          [3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
  146.          [0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
  147.          [13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]],
  148.  
  149.         [[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
  150.          [13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
  151.          [13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
  152.          [1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]],
  153.  
  154.         [[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
  155.          [13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
  156.          [10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
  157.          [3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]],
  158.  
  159.         [[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
  160.          [14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
  161.          [4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
  162.          [11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]],
  163.  
  164.         [[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
  165.          [10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
  166.          [9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
  167.          [4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]],
  168.  
  169.         [[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
  170.          [13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
  171.          [1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
  172.          [6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]],
  173.  
  174.         [[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
  175.          [1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
  176.          [7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
  177.          [2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]]
  178.  
  179. # Tabla de permutación final
  180. final_perm = [40, 8, 48, 16, 56, 24, 64, 32,
  181.               39, 7, 47, 15, 55, 23, 63, 31,
  182.               38, 6, 46, 14, 54, 22, 62, 30,
  183.               37, 5, 45, 13, 53, 21, 61, 29,
  184.               36, 4, 44, 12, 52, 20, 60, 28,
  185.               35, 3, 43, 11, 51, 19, 59, 27,
  186.               34, 2, 42, 10, 50, 18, 58, 26,
  187.               33, 1, 41, 9, 49, 17, 57, 25]
  188.  
  189.  
  190. def encrypt(pt, rkb, rk):
  191.     pt = hexAbin(pt)
  192.  
  193.     # Permutación inicial
  194.     pt = permute(pt, initial_perm, 64)
  195.     print("Después de la permutación inicial", binAhex(pt))
  196.  
  197.     # Splitting
  198.     left = pt[0:32]
  199.     right = pt[32:64]
  200.     for i in range(0, 16):
  201.         # Expansión D-box: Expansión de los datos de 32 bits a 48 bits
  202.         right_expanded = permute(right, exp_d, 48)
  203.  
  204.         # XOR RoundKey [i] y right_expanded
  205.         xor_x = xor(right_expanded, rkb[i])
  206.  
  207.         # S-boxes: sustituyendo el valor de la tabla s-box calculando fila y columna
  208.         sbox_str = ""
  209.         for j in range(0, 8):
  210.             row = binAdec(int(xor_x[j * 6] + xor_x[j * 6 + 5]))
  211.             col = binAdec(int(xor_x[j * 6 + 1] + xor_x[j * 6 + 2] + xor_x[j * 6 + 3] + xor_x[j * 6 + 4]))
  212.             val = sbox[j][row][col]
  213.             sbox_str = sbox_str + decAbin(val)
  214.  
  215.         #Caja D recta: después de sustituir la reordenación de los bits
  216.         sbox_str = permute(sbox_str, per, 32)
  217.  
  218.         # XOR izquierda y sbox_str
  219.         result = xor(left, sbox_str)
  220.         left = result
  221.  
  222.         # Intercambiadora
  223.         if (i != 15):
  224.             left, right = right, left
  225.         print("rondas ", i + 1, " ", binAhex(left), " ", binAhex(right), " ", rk[i])
  226.  
  227.     # Combinación
  228.     combine = left + right
  229.  
  230.     # Permutación final: reordenamiento final de bits para obtener texto cifrado
  231.     cipher_text = permute(combine, final_perm, 64)
  232.     return cipher_text
  233.  
  234.  
  235.  
  236. print("ingresa tu texto en binario o hexadecimal")
  237. pt = input()
  238. print("ingresa tu Key en binario o hexadecimal")
  239. key = input()
  240.  
  241. # Generación de claves
  242. # --hex a binario
  243. key = hexAbin(key)
  244.  
  245. # --tabla de eliminación de bits de paridad
  246. keyp = [57, 49, 41, 33, 25, 17, 9,
  247.         1, 58, 50, 42, 34, 26, 18,
  248.         10, 2, 59, 51, 43, 35, 27,
  249.         19, 11, 3, 60, 52, 44, 36,
  250.         63, 55, 47, 39, 31, 23, 15,
  251.         7, 62, 54, 46, 38, 30, 22,
  252.         14, 6, 61, 53, 45, 37, 29,
  253.         21, 13, 5, 28, 20, 12, 4]
  254.  
  255. # obtener una clave de 56 bits de 64 bits usando los bits de paridad
  256. key = permute(key, keyp, 56)
  257.  
  258. # Número de cambios de bits
  259. shift_table = [1, 1, 2, 2,
  260.                2, 2, 2, 2,
  261.                1, 2, 2, 2,
  262.                2, 2, 2, 1]
  263.  
  264. # Tabla de compresión de claves: compresión de claves de 56 bits a 48 bits
  265. key_comp = [14, 17, 11, 24, 1, 5,
  266.             3, 28, 15, 6, 21, 10,
  267.             23, 19, 12, 4, 26, 8,
  268.             16, 7, 27, 20, 13, 2,
  269.             41, 52, 31, 37, 47, 55,
  270.             30, 40, 51, 45, 33, 48,
  271.             44, 49, 39, 56, 34, 53,
  272.             46, 42, 50, 36, 29, 32]
  273.  
  274. # Splitting
  275. left = key[0:28]  # rkbpara RoundKeys en binario
  276. right = key[28:56]  # rk para RoundKeys en hexadecimal
  277.  
  278. rkb = []
  279. rk = []
  280. for i in range(0, 16):
  281.     #Cambiando los bits por enésimo turnos comprobando desde la tabla de turnos
  282.     left = shift_left(left, shift_table[i])
  283.     right = shift_left(right, shift_table[i])
  284.  
  285.     # Combinación de STRING izquierda y derecha
  286.     combine_str = left + right
  287.  
  288.     # Compresión de clave de 56 a 48 bits
  289.     round_key = permute(combine_str, key_comp, 48)
  290.  
  291.     rkb.append(round_key)
  292.     rk.append(binAhex(round_key))
  293.  
  294. print("Encriptacion")
  295. cipher_text = binAhex(encrypt(pt, rkb, rk))
  296. print("Texto Cifrado : ", cipher_text)
  297.  
  298. print("\nDecencriptacion")
  299. rkb_rev = rkb[::-1]
  300. rk_rev = rk[::-1]
  301. text = binAhex(encrypt(cipher_text, rkb_rev, rk_rev))
  302. print("Texto Plano : ", text)
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