python实现des与RSA

密码学
Created At :
Views 👀 :
  • des的实现
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
#_*_ coding:utf-8 _*_
from base64 import b64decode,b64encode

global IP_table,IP_re_table,E,P,S,PC_1,PC_2,SHIFT


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]

IP_re_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]

E  = [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 = [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]

S =  [
 [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 ],

[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],

[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 ],

[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],

[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],

[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],

[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],

[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]
]
#key
PC_1 = [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]
PC_2 = [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]
#秘钥左移的位数
SHIFT = [1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1]




#初始置换
def IP(string):
     m=""
     for i in range(len(string)):
          m+=string[IP_table[i]-1]
     return m
#初始逆置换
def IP_re(string):
     lens=len(string)/4
     temp_list=''
     for i in range(lens):
          list=''
          for j in range(4):
               list+=string[IP_re_table[i*4+j]-1]
          temp_list+="%x" %int(list,2)
     return temp_list

#子密钥生成
def key_append(string):
     key=[]  
     string=PC1(string)
     for i in range(16):
          string=left(string,SHIFT[i])
          key.append(PC2(string))
     return key
#循环左移
def left(string,num):
     l=string[0:28]
     r=string[28:56]
     l=l[num:28]+l[0:num]
     r=r[num:28]+r[0:num]
     string=l+r
     return string
#PC1置换
def PC1(string):
     key=""
     for i in range(56):
          key+=string[PC_1[i]-1]
     return key
#PC2生成
def PC2(string):
     key=""
     for i in range(48):
          key+=string[PC_2[i]-1]
     return key
#E盒扩展
def E_box(string):
     m=""
     for i in range(len(E)):
          m+=string[E[i]-1]
     return m


#Pbox置换
def p_box(string):
     s=""
     for i in range(32):
          s+=string[P[i]-1]
     return s

#sbox置换
def S_sub(my_str):
     res = ""
     c = 0
     for i in range(0,len(my_str),6):
          now_str = my_str[i:i+6]
          row = int(now_str[0]+now_str[5],2)
          col = int(now_str[1:5],2)
          num = bin(S[c][row*16 + col])[2:]   #利用了bin输出有可能不是4位str类型的值，所以才有下面的循环并且加上字符0
          for gz in range(0,4-len(num)):
               num = '0'+ num
          res += num
          c  += 1
     return res

#将十六进制转换为二进制字符串
def hex_to_bin(code,lens):
	return_code=''
	lens=lens%16
	for key in code:
		code_ord=int(key,16)
		return_code+=Tow(code_ord,4)		
	if lens!=0:
		return_code+='0'*(16-lens)*4
	return return_code
	
#二进制转换
def Tow(o,lens):
	return_code=''
	for i in range(lens):
		return_code=str(o>>i &1)+return_code
	return return_code

#将unicode字符转换为16进制
def str_to_hex(string):
	return_string=''
	for i in string:
		return_string+="%02x"%ord(i)
	return return_string
		
def hex_to_str(string):
	return_string=''
	string_len=len(string)
	for i in range(0,string_len,2):
		return_string+=chr(int(string[i:i+2],16))
	return return_string

#异或
def xor(code,key):
	code_len=len(key)
	return_list=''
	for i in range(code_len):
		if code[i]==key[i]:
			return_list+='0'
		else:
			return_list+='1'
	return return_list



def encrypt(Ln,Rn,oldRn,temp_key):
     Rn=E_box(Rn)
     Rn=p_box(S_sub(xor(Rn,temp_key)))
     Rn=xor(Ln,Rn)
     message=oldRn+Rn
     return message

def encrypt1(message,key):
     out=""
     len_key=len(key)
     len_message=len(message)
     key1=hex_to_bin(key,len_key)
     message=hex_to_bin(message,len_message)
     #长度填充
     if len_message%16!=0:
		real_len=(len_message/16)*16+16
     else:
		real_len=len_message
     if len_key%16!=0:
		len_key=(len_key/16)*16+16
     len_key*=4
	#每个16进制占4位
     len_end=4*real_len
     print len_end
     for i in range(0,len_end,64):
          string=message[i:i+64]
          l=i%len_key
          test_key=key1[l:l+64]
          string=IP(string)
          key=[]
          key=key_append(test_key)
          
          for j in range(16):
               Ln=string[0:32]
               Rn=oldRn=string[32:64]
               string=encrypt(Ln,Rn,oldRn,key[j])
          Ln=string[0:32]
          Rn=string[32:64]
          out+=IP_re(Rn+Ln)
     return out


def decrypt(Ln,Rn,oldRn,temp_key):
     Rn=E_box(Rn)
     Rn=p_box(S_sub(xor(Rn,temp_key)))
     Rn=xor(Ln,Rn)
     message=oldRn+Rn
     return message
     
def decrypt1(message,key):
     out=''
     len_key=len(key)
     len_message=len(message)
     key1=hex_to_bin(key,len_key)
     message=hex_to_bin(message,len_message)
     #长度填充
     if len_message%16!=0:
		return False
     if len_key<1 or len_message<1:
		return False
     if len_key%16!=0:
	     len_key=(len_key/16)*16+16
     len_key*=4
     len_end=len_message*4

     for i in range(0,len_end,64):
          string=message[i:i+64]
          l=i%len_key
          test_key=key1[l:l+64]

          string=IP(string)
          key=[]
          key=key_append(test_key)
          
          for j in range(16):
               Ln=string[0:32]
               Rn=oldRn=string[32:64]
               string=decrypt(Ln,Rn,oldRn,key[15-j])
          Ln=string[0:32]
          Rn=string[32:64]
          out+=IP_re(Rn+Ln)
     return out


def main():
     while True:
          m=raw_input("1.encrypt  2.decrypt  3.exit\n")
          if m=='1':
               message=str_to_hex(raw_input("enter message:"))
               key=str_to_hex(raw_input("enter key:"))
               print b64encode(encrypt1(message,key))     
          elif m=='2':
               message=b64decode(raw_input("enter encrypt:"))
               key=str_to_hex(raw_input("enter key:"))
               print hex_to_str(decrypt1(message,key))
          elif m=='3':
               exit(0)
          else:
               print "it is False"
               main()

if __name__ =='__main__':
     main()
  • rsa的实现
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
#_*_ coding:utf-8 _*_
import random



# 求两个数字的最大公约数（欧几里得算法）
def gcd(a, b):
  if b == 0:
    return a
  else:
    return gcd(b, a % b)

#扩展欧几里
def ext_gcd(a, b):
  if b == 0:
    x1 = 1
    y1 = 0
    x = x1
    y = y1
    r = a
    return x, y,r
  else:
    x1, y1,r = ext_gcd(b, a % b)
    x = y1
    y = x1 - (a // b) * y1
    return x, y,r

# 快速幂模
def fastExpMod(b, e, m):
    result = 1
    while e != 0:
        if (e&1) == 1:
            # ei = 1, then mul
            result = (result * b) % m
        e >>= 1
        # b, b^2, b^4, b^8, ... , b^(2^n)
        b = (b*b) % m
    return result

#开始选择p q
def get_prime(test_len):
    while True:
        n = random.randint(0, 1 << test_len)#求2^test_len之间的大数
        if n % 2 != 0:
            found = True
            # 随机性测试
            for i in range(0, 5):   #5的时候错误率已经小于千分之一
                if prime_check(n) == False:
                    found = False
                    break
            if found == True:
                return n

#Miller-Rabin，测试n是否为素数
def prime_check(n):
    q = n - 1
    k = 0
    # 寻找k,q 是否满足2^k*q =n - 1
    while q % 2 == 0:
        k += 1
        q = q // 2
    a = random.randint(2, n - 2)
    # 如果 a^q mod n= 1, n 可能是一个素数
    if fastExpMod(a, q, n) == 1:
        return True
    # 如果存在j满足 a ^ ((2 ^ j) * q) mod n == n-1, n 可能是一个素数
    for j in range(0, k):
        if fastExpMod(a, (2 ** j) * q, n) == n - 1:
            return True
    # n 不是素数
    return False
#获取key
def get_key(lens):
    while True:
        p=get_prime(lens)
        q=get_prime(lens)
        e=65537
        phi=(p-1)*(q-1)
        x,y,z=ext_gcd(phi,e)
        if y<0:
            d=y+phi
        else:
            d=y
        return (p*q,e,d)

def main():
    lens=int(raw_input("please enter bits for p/q:\n"))#输入p,q的长度
    n,e,d=get_key(lens)
    message=raw_input("please enter message:\n")#输入明文
    message=int(message.encode('hex'),16)
    if len(bin(message)[2:])>len(bin(n)[2:]):#判断明文与N的长度
        print "The lens of message bigger than lens of N"
        return False
    #快速幂模求密文
    c=fastExpMod(message,e,n)
    print "n:%d\ne:%d\nd:%d\n"%(n,e,d)
    print "cipher is:%d"%c
    a=raw_input("DECRYPT?(Y/N)")
    if a=="Y" or a=="y":
        #快速幂模求明文
        m=fastExpMod(c,d,n)
        print "message is:"+hex(m)[2:-1].decode('hex')
    elif a=='N' or a=='n':
        print "the cipher is%d"%c
        exit(0)

if __name__ =='__main__':
    main()
转载请注明来源，欢迎对文章中的引用来源进行考证，欢迎指出任何有错误或不够清晰的表达。可以在下面评论区评论，也可以邮件至 1259742453@qq.com

💰

©2016-2020 weichujian

Built with Hexo and 3-hexo theme

×

Help us with donation