f函数

# -*- coding = utf-8 -*-
# @Time : 2021/9/22 20:21
# @Author : 刘卓文
# @File : F.py
# @Software : PyCharm


MaxTime = 16
  # IP置换表

IP_table = [58, 50, 42, 34, 26, 18, 10, 2,
                       60, 52, 44, 36, 28, 20, 12, 4,
                       62, 54, 46, 38, 30, 22, 14, 6,
                       64, 56, 48, 40, 32, 24, 16, 8,
                       57, 49, 41, 33, 25, 17, 9, 1,
                       59, 51, 43, 35, 27, 19, 11, 3,
                       61, 53, 45, 37, 29, 21, 13, 5,
                       63, 55, 47, 39, 31, 23, 15, 7]
  # 逆IP置换表

Inv_IP_table = [40, 8, 48, 16, 56, 24, 64, 32,
                               39, 7, 47, 15, 55, 23, 63, 31,
                               38, 6, 46, 14, 54, 22, 62, 30,
                               37, 5, 45, 13, 53, 21, 61, 29,
                               36, 4, 44, 12, 52, 20, 60, 28,
                               35, 3, 43, 11, 51, 19, 59, 27,
                              34, 2, 42, 10, 50, 18, 58, 26,
                               33, 1, 41, 9, 49, 17, 57, 25]
  # S盒中的S1盒

S1 = [14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
            0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
            4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
          15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]
  # S盒中的S2盒

S2 = [15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
            3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
            0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
           13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]
  # S盒中的S3盒

S3 = [10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
          13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
          13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
            1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]
  # S盒中的S4盒

S4 = [7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
          13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
          10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
           3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]
  # S盒中的S5盒

S5 = [2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
          14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
          4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
           11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]
  # S盒中的S6盒

S6 = [12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
           10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
            9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
            4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]
  # S盒中的S7盒

S7 = [4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
           13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
            1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
           6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]
  # S盒中的S8盒

S8 = [13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
            1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
            7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
            2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]
  # S盒

S = [S1, S2, S3, S4, S5, S6, S7, S8]
  # 用于对数据进行扩展置换，将32bit数据扩展为48bit

extend_table = [32, 1, 2, 3, 4, 5,
                                4, 5, 6, 7, 8, 9,
                                8, 9, 10, 11, 12, 13,
                               12, 13, 14, 15, 16, 17,
                               16, 17, 18, 19, 20, 21,
                               20, 21, 22, 23, 24, 25,
                               24, 25, 26, 27, 28, 29,
                               28, 29, 30, 31, 32, 1]
  # P盒

P_table = [16, 7, 20, 21, 29, 12, 28, 17,
                       1, 15, 23, 26, 5, 18, 31, 10,
                       2, 8, 24, 14, 32, 27, 3, 9,
                      19, 13, 30, 6, 22, 11, 4, 25]

# 轮函数F()

    # 32bitR0/L0-->48bitR0/L0    # E扩展置换
    # 48bitR0/L0⨁48bitK1 #K1通过密钥生成获得
    # 48R0/L0--S盒压缩-->32bitR0/L0
    # 32bitR0/L0--P盒置换-->32bitR0/L0
def intiBit(n):
    a=[]
    for i in range(0,4):
        a.insert(0,str(n%2))
        n = int(n/2)
    return a
def IP(text,op):
    tmp = [0 for i in range(64)]
    if op == 0:
        for i in range(64):
            tmp[i] = text[IP_table[i]-1]
        return tmp
    if op == 1:
        for i in range(64):
            tmp[i] = text[Inv_IP_table[i]-1]
        return tmp
def Ebox(text):
    extend = [0 for i in range(48)]
    for i in range(48):
        extend[i] = text[extend_table[i]-1]
    return extend
def Sbox(text):
    sResult = [0 for k in range(32)]
    for k in range(8):
        row = 2*int(text[k*6]) + int(text[k*6+5])
        column = 8 * int(text[k * 6 + 1]) + 4 * int(text[k * 6 + 2]) + 2 * int(text[k * 6 + 3]) + int(text[k * 6 + 4])
        tmp = S[k][row*16+column]
        for i in range(4):
            sResult[4*k+i] = intiBit(tmp)[i]
    return sResult
def Pbox(text):
    pResult = [0 for i in range(32)]
    for i in range(32):
        pResult[i] = text[P_table[i]-1]
        return pResult
def Xor(bit1,bit2):
    xResult = [0 for i in range(len(bit1))]
    for i in range(len(bit1)):
        xResult[i] = str(int(bit1[i]) ^ int(bit2[i]))
    return xResult

密钥的生成

# -*- coding = utf-8 -*-
# @Time : 2021/9/22 18:48
# @Author : 刘卓文
# @File : key.py
# @Software : PyCharm

pc1=[ 57, 49, 41, 33, 25, 17,  9,
               1, 58, 50, 42, 34, 26, 18,
               10,  2, 59, 51, 43, 35, 27,
               19, 11,  3, 60, 52, 44, 36,
               63, 55, 47, 39, 31, 23, 15,
                7, 62, 54, 46, 38, 30, 22,
               14,  6, 61, 53, 45, 37, 29,
              21, 13,  5, 28, 20, 12,  4 ]
     #生成子密钥的置换表2，将56位的密钥转换为48位
pc2=[ 14, 17, 11, 24,  1,  5,
               3, 28, 15,  6, 21, 10,
             23, 19, 12,  4, 26,  8,
             16,  7, 27, 20, 13,  2,
             41, 52, 31, 37, 47, 55,
             30, 40, 51, 45, 33, 48,
            44, 49, 39, 56, 34, 53,
             46, 42, 50, 36, 29, 32 ]
# 将64bit密钥K0根据PC-1表进行置换得到56bit数据
# 将56bit数据分为28bit的C0&D0
# C0&D0根据移位次数表移位得到C1&D1    # 该处位移为2*28bit的循环左移
# C1&D1结果拼接之后的56bit数据根据PC-2表进行置换得到48bit密钥K1
# 重复3-4直到16次 # 每一次的移位都是在上一对C&D的基础上移位
      #生成子密钥的置换表1，将64位的密钥转换为56位
#循环左移
def Listmove(l,step):
    return l[step:] + l[:step]
def createKey(key):
    keyresult = []
    key0 = [0 for i in range(56)]
    for i in range(len(pc1)):
        key0[i] = key[pc1[i]-1]
    for i in range(16):
        key1 = [0 for i in range(48)]
        if(i==0 or i ==1 or i == 8 or i == 15):
            step = 1
        else:
            step = 2
        tmp1 = key0[0:28]
        tmp2 = key0[28:56]
        tmp1 = Listmove(tmp1,step)
        tmp2 = Listmove(tmp2,step)
        key0 = tmp1 + tmp2
        for i in range(len(pc2)):
            key1[i] = key0[pc2[i]-1]
        keyresult.append(key1)
    return keyresult

des加密

import key as cs
import F as f
#十六进制转二进制比特串
def Hexbin(text):
    result = []
    for i in range(len(text)):
        result.extend(f.intiBit(int(text[i],16)))
    return result
#二进制比特串转十六进制
def bin2Hex(text):
    result = []
    q = len(text)//4
    for i in range(q):
        dec = int(text[4*i])*8 + int(text[4*i+1])*4 + int(text[4*i+2])*2 + int(text[4*i+3])*1
        x = hex(dec)[2:].upper()
        result.extend(x)
    rs = ''.join(result)
    return rs
def desEncryption(text,key):
    keyList = cs.createKey(keybit)
    text1 = f.IP(text,0)
    L = [text1[i] for i in range(32)]
    R = [text1[i] for i in range(32, 64)]
    for i in range(16):
          tmp = R
          tmp = f.Ebox(tmp)
          tmp = f.Xor(tmp,keyList[15-i])
          tmp = f.Sbox(tmp)
          tmp = f.Pbox(tmp)
          tmp = f.Xor(tmp,L)
          L = R
          R = tmp
    L,R = R,L
    ctext = L
    ctext.extend(R)
    ctext = f.IP(ctext,1)
    return bin2Hex(ctext)
if __name__ == '__main__':
     plaintext = input("请输入用十六进制表示的明文:")
     key = input("请输入用十六进制表示的密钥：")
     ptext = Hexbin(plaintext)
     keybit = Hexbin(key)
     print('输出的密文为：' + desEncryption(ptext, keybit))