Python 实现AES算法

#1 纯属闲的没事干

#2 参考书籍<<程序员密码学>>

  1 #coding:utf-8
  2 __author__ = 'Kerne0'
  3 class AESE():
  4     def __init__(self,blk,key,Nr):
  5         self.blk=blk
  6         self.key=key
  7         self.Nr=Nr
  8         self.sbox=( 0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76,
  9                     0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0,
 10                     0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15,
 11                     0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75,
 12                     0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84,
 13                     0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf,
 14                     0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8,
 15                     0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2,
 16                     0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73,
 17                     0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb,
 18                     0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79,
 19                     0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08,
 20                     0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a,
 21                     0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e,
 22                     0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf,
 23                     0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16 )
 24 #xtime process
 25     def xtime(self,x):
 26         if(x&0x80):
 27             return (((x<<1)^0x1b)&0xff)
 28         return x<<1
 29 #MixColumns: Process the entire block
 30     def MixColumns(self):
 31         tmp=[0 for t in range(4)]
 32         xt=[0 for q in range(4)]
 33         n=0
 34         for x in range(4):
 35             xt[0]=self.xtime(self.blk[n])
 36             xt[1]=self.xtime(self.blk[n+1])
 37             xt[2]=self.xtime(self.blk[n+2])
 38             xt[3]=self.xtime(self.blk[n+3])
 39             tmp[0]=xt[0]^xt[1]^self.blk[n+1]^self.blk[n+2]^self.blk[n+3]
 40             tmp[1]=self.blk[n]^xt[1]^xt[2]^self.blk[n+2]^self.blk[n+3]
 41             tmp[2]=self.blk[n]^self.blk[n+1]^xt[2]^xt[3]^self.blk[n+3]
 42             tmp[3]=xt[0]^self.blk[n]^self.blk[n+1]^self.blk[n+2]^xt[3]
 43             self.blk[n]=tmp[0]
 44             self.blk[n+1]=tmp[1]
 45             self.blk[n+2]=tmp[2]
 46             self.blk[n+3]=tmp[3]
 47             n=n+4
 48 #ShiftRows:Shifts the entire block
 49     def ShiftRows(self):
 50         #2nd row
 51         t=self.blk[1]
 52         self.blk[1]=self.blk[5]
 53         self.blk[5]=self.blk[9]
 54         self.blk[9]=self.blk[13]
 55         self.blk[13]=t
 56         #3nd row
 57         t=self.blk[2]
 58         self.blk[2]=self.blk[10]
 59         self.blk[10]=t
 60         t=self.blk[6]
 61         self.blk[6]=self.blk[14]
 62         self.blk[14]=t
 63         #4nd row
 64         t=self.blk[15]
 65         self.blk[15]=self.blk[11]
 66         self.blk[11]=self.blk[7]
 67         self.blk[7]=self.blk[3]
 68         self.blk[3]=t
 69 #SubBytes
 70     def SubBytes(self):
 71         for x in range(16):
 72             self.blk[x]=self.sbox[self.blk[x]]
 73 #AddRoundKey
 74     def AddRoundKey(self,key):
 75         x=0
 76         k=[0 for m in range(16)]
 77         for c in range(4):
 78             for r in range(4):
 79                 k[x]=key[r][c]
 80                 x=x+1
 81         for y in range(16):
 82             self.blk[y]^=int(k[y])
 83 
 84     def show(self):
 85         for i in range(16):
 86             print hex(self.blk[i])
 87 # Schedule a secret key for use.
 88     def ScheduleKey(self,w,Nk):
 89         Rcon=[0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x1b,0x36]
 90         for r in range(4):
 91             for c in range(4):
 92                 w[0][r][c]=self.key[r+c*4]
 93         for i in range(1,self.Nr+1,1):#问题1
 94             for j in range(Nk):
 95                 t=[0 for x in range(4)]
 96                 for r in range(4):
 97                     if j :
 98                         t[r]=w[i][r][j-1]
 99                     else:
100                         t[r]=w[i-1][r][3]
101                 if j==0:
102                     temp=t[0]
103                     for r in range(3):
104                         t[r]=self.sbox[t[(r+1)%4]]
105                     t[3]=self.sbox[temp]
106                     t[0]^=int(Rcon[i-1])
107                 for r in range(4):
108                     w[i][r][j]=w[i-1][r][j]^t[r]
109 
110     #加密函数
111     def AesEncrypt(self):
112         outkey=[]
113         outkey=[[[0 for  col in range(4)] for row in range(4)] for s in range(11)]
114         self.ScheduleKey(outkey,4)
115         self.AddRoundKey(outkey[0])
116         for x in range(1,self.Nr,1):
117             self.SubBytes()
118             self.ShiftRows()
119             self.MixColumns()
120             self.AddRoundKey(outkey[x])
121         self.SubBytes()
122         self.ShiftRows()
123         self.AddRoundKey(outkey[10])
124         print "密文的16进制:"
125         cText=""
126         for i in range(16):
127             xxl=hex(self.blk[i])
128             cText+=xxl[2:]
129         print cText
130         return blk
131 
132 class AESD():
133     def __init__(self,blk,key,Nr):
134         self.blk=blk
135         self.key=key
136         self.Nr=Nr
137         self.sbox=( 0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76,
138                     0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0,
139                     0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15,
140                     0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75,
141                     0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84,
142                     0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf,
143                     0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8,
144                     0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2,
145                     0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73,
146                     0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb,
147                     0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79,
148                     0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08,
149                     0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a,
150                     0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e,
151                     0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf,
152                     0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16 )
153 
154     def xtime(self,x):
155         if(x&0x80):
156             return (((x<<1)^0x1b)&0xff)
157         return x<<1
158 
159     def ReMixColumns(self):
160         tmp=[0 for q in range(4)]
161         xt1=[0 for w in range(4)]
162         xt2=[0 for e in range(4)]
163         xt3=[0 for r in range(4)]
164         n=0
165         for x in range(4):
166             xt1[0]=self.xtime(self.blk[n])
167             xt1[1]=self.xtime(self.blk[n+1])
168             xt1[2]=self.xtime(self.blk[n+2])
169             xt1[3]=self.xtime(self.blk[n+3])
170             xt2[0]=self.xtime(self.xtime(self.blk[n]))
171             xt2[1]=self.xtime(self.xtime(self.blk[n+1]))
172             xt2[2]=self.xtime(self.xtime(self.blk[n+2]))
173             xt2[3]=self.xtime(self.xtime(self.blk[n+3]))
174             xt3[0]=self.xtime(self.xtime(self.xtime(self.blk[n])))
175             xt3[1]=self.xtime(self.xtime(self.xtime(self.blk[n+1])))
176             xt3[2]=self.xtime(self.xtime(self.xtime(self.blk[n+2])))
177             xt3[3]=self.xtime(self.xtime(self.xtime(self.blk[n+3])))
178             tmp[0]=xt1[0]^xt2[0]^xt3[0]^ self.blk[n+1]^xt1[1]^xt3[1]^ self.blk[n+2]^xt2[2]^xt3[2]^self.blk[n+3]^xt3[3]
179             tmp[1]=self. blk[n]^xt3[0]^xt1[1]^xt2[1]^xt3[1]^ self.blk[n+2]^xt1[2]^xt3[2]^ self.blk[n+3]^xt2[3]^xt3[3]
180             tmp[2]= self.blk[n]^xt2[0]^xt3[0]^ self.blk[n+1]^xt3[1]^xt1[2]^xt2[2]^xt3[2]^ self.blk[n+3]^xt1[3]^xt3[3]
181             tmp[3]=self. blk[n]^xt1[0]^xt3[0]^self. blk[n+1]^xt2[1]^xt3[1]^ self.blk[n+2]^xt3[2]^xt1[3]^xt2[3]^xt3[3]
182             self.blk[n]=tmp[0]
183             self.blk[n+1]=tmp[1]
184             self.blk[n+2]=tmp[2]
185             self.blk[n+3]=tmp[3]
186             n=n+4
187 
188     def ReShiftRows(self):
189         #2nd row
190         t=self.blk[13]
191         self.blk[13]=self.blk[9]
192         self.blk[9]=self.blk[5]
193         self.blk[5]=self.blk[1]
194         self.blk[1]=t
195         #3rd row
196         t=self.blk[2]
197         self.blk[2]=self.blk[10]
198         self.blk[10]=t
199         t=self.blk[6]
200         self.blk[6]=self.blk[14]
201         self.blk[14]=t
202         #4th row
203         t=self.blk[3]
204         self.blk[3]=self.blk[7]
205         self.blk[7]=self.blk[11]
206         self.blk[11]=self.blk[15]
207         self.blk[15]=t
208 
209     def ReSubBytes(self):
210         for i in range(16):
211             for j in range(256):
212                 if(self.sbox[j]==self.blk[i]):
213                     self.blk[i]=j
214                     break
215 
216     def AddRoundKey(self,key):
217         x=0
218         k=[0 for m in range(16)]
219         for c in range(4):
220             for r in range(4):
221                 k[x]=key[r][c]
222                 x=x+1
223         for y in range(16):
224             self.blk[y]^=k[y]
225 
226     def ScheduleKey(self,w,Nk):
227         Rcon=[0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x1b,0x36]
228         for r in range(4):
229             for c in range(4):
230                 w[0][r][c]=self.key[r+c*4]
231         for i in range(1,self.Nr+1,1):
232             for j in range(Nk):
233                 t=[0 for x in range(4)]
234                 for r in range(4):
235                     if j :
236                         t[r]=w[i][r][j-1]
237                     else:
238                         t[r]=w[i-1][r][3]
239                 if j==0:
240                     temp=t[0]
241                     for r in range(3):
242                         t[r]=self.sbox[t[(r+1)%4]]
243                     t[3]=self.sbox[temp]
244                     t[0]^=int(Rcon[i-1])
245                 for r in range(4):
246                     w[i][r][j]=w[i-1][r][j]^t[r]
247 
248     def AesDecrpyt(self):
249         outkey=[]
250         outkey=[[[0 for  col in range(4)] for row in range(4)] for s in range(11)]#改
251         self.ScheduleKey(outkey,4)
252         self.AddRoundKey(outkey[10])
253         self.ReShiftRows()
254         self.ReSubBytes()
255         for x in range(self.Nr-1,0,-1):
256             self.AddRoundKey(outkey[x])
257             self.ReMixColumns()#第二次循环出问题了
258             self.ReShiftRows()
259             self.ReSubBytes()
260         self.AddRoundKey(outkey[0])
261         print "解密结果:"
262         mText=""
263         for x in range(16):
264             mText+=chr(self.blk[x])
265         print mText
266 def StringToListN(string):
267     s=[0 for x in range(16)]
268     l=len(string)
269     for x in range(l):
270         s[x]=int(ord(string[x]))
271     return s
272 
273 if __name__=="__main__":
274     #加密
275     plainText=raw_input("请输入待加密的字符串:")
276     blk=StringToListN(plainText)
277     skey=raw_input("请输入待加密的秘钥:")
278     key=StringToListN(skey)
279     a=AESE(blk,key,10)
280     rblk=a.AesEncrypt()
281     #解密
282     b=AESD(rblk,key,10)
283     b.AesDecrpyt()

运行结果截图: