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@Lin-- 2020-01-02T12:39:51.000000Z 字数 11148 阅读 448

ComSec作业8--Project:AES磁盘加密软件

ComSec

AES_S-Box and its inverse

  1. '''
  2. # File : AES_Box.py
  3. # Author : Hongpei Lin
  4. # Date : 20191111
  5. # Purpose : In algorithm AES
  6. # build S-Box in SubBytes
  7. '''
  8. #multilpy in GF(2^8)
  9. def mul(a,b):
  10.     r=0
  11.     while b:
  12.         if b%2:
  13.             r=r^a #add operation : XOR
  14.         b=b>>1
  15.         if a&int('10000000',2)==0: #first bit's value = 0
  16.             a=a<<1
  17.         else: #first bit's value = 1
  18.             a=a<<1
  19.             a=a^283
  20.     return r
  21. #compute the max index number which < 2^count
  22. #return count, from 0
  23. def highest_bit(n):
  24.     count = 0
  25.     while n:
  26.         count+=1
  27.         n=n>>1
  28.     return count-1
  29. #division about polymerization
  30. #return quotient and remainder
  31. def div(a,b):
  32.     if a==b:
  33.         return 1,0
  34.     if a<b:
  35.         return 0,a
  36.     a_bit = highest_bit(a)
  37.     b_bit = highest_bit(b)
  38.     result = 0
  39.     while not a_bit<b_bit:
  40.         move=a_bit-b_bit
  41.         temp=b<<move
  42.         result=result+(1<<move)
  43.         a=a^temp
  44.         a_bit=highest_bit(a)
  45.     return result,a
  46. #compute the inverse about a', where a*a'=1(mod m)
  47. #the algorithrm likes EGCD
  48. def inverse(a,m):
  49.     r0,s0,r1,s1=1,0,0,1
  50.     while m>0:
  51.         t=m
  52.         q,m=div(a,m)#q=a//m,m=a mod m
  53.         a=t#a=m
  54.         r0,r1=r1,r0^mul(q,r1)#sub operation:XOR
  55.         s0,s1=s1,s0^mul(q,s1)
  56.     return r0 #a'
  58. #build the matrix  to multiply b0-b7 in step 3
  59. def build_T(T_value):
  60.     T_List=[]
  61.     for i in range(8):
  62.         T_List.append(T_value)
  63.         if T_value&1:
  64.             T_value=(T_value>>1)^int('10000000',2)
  65.         else:
  66.             T_value=T_value>>1
  67.     return T_List
  69. #compute every value's inverse in a matrix
  70. def S_inverse(S):
  71.     for i in range(len(S)):
  72.         for j in range(len(S[0])):
  73.             S[i][j]=inverse(S[i][j],283)
  74.     return S
  76. def build_byte_order_S(S):
  77.     for i in range(len(S)):
  78.         for j in range(len(S[0])):
  79.             S[i][j]=(i<<4)+j
  80.     return S
  82. def Compute_S_Box(T,S,c):
  83.     for i in range(len(S)):
  84.         for j in range(len(S[0])):
  85.             # In order to multiply matrix T,let every bit in a byte reverse.
  86.             Bit=list('{:08b}'.format(S[i][j]))
  87.             Bit.reverse()
  88.             Bit_s=""
  89.             for k in Bit:
  90.                 Bit_s=Bit_s+str(k)
  91.             Bit=int(Bit_s,2)
  92.             # T */& b0-b7
  93.             T_result=[]
  94.             for l in T:
  95.                 And=l&Bit
  96.                 And_list=list('{:08b}'.format(And))
  97.                 And_reslut=int(And_list[0],2)
  98.                 for m in And_list[1:]:
  99.                     And_reslut=And_reslut^int(m,2)
  100.                 T_result.append(And_reslut)
  101.             T_result_s=""
  102.             for n in T_result:
  103.                 T_result_s=T_result_s+str(n)
  104.             # get the reslut +/XOR c/63's reverse bits
  105.             S_temp=int(T_result_s,2)^c
  106.             S_temp=list('{:08b}'.format(S_temp))
  107.             S_temp.reverse()#reverse again, get the final answer
  108.             S_temp_s=""
  109.             for o in S_temp:
  110.                 S_temp_s=S_temp_s+str(o)
  111.             S[i][j]=int(S_temp_s,2)
  112.     return S
  114. def SubByte(S_BOX,n):
  115.     high_four=(n&int('11110000',2))>>4
  116.     low_four=(n&int('00001111',2))
  117.     return S_BOX[high_four][low_four]
  119. T=[]
  120. T_v=143
  121. T_vi=37
  122. c=int('11000110',2)
  123. ci=int('10100000',2)
  124. S1=[[0]*16 for i in range(16)]#S_Box
  125. Si=[[0]*16 for i in range(16)]#S_Box_Inverse
  127. #Generate S-Box
  128. S1=build_byte_order_S(S1)
  129. S1=S_inverse(S1)
  130. T=build_T(T_v)
  131. S1=Compute_S_Box(T,S1,c)
  133. #Generate Inverse S-Box
  134. Si=build_byte_order_S(Si)
  135. T=build_T(T_vi)
  136. Si=Compute_S_Box(T,Si,ci)
  137. Si=S_inverse(Si)
  139. '''
  140. #print the S-Box
  141. for i in range(16):
  142.     for j in range(16):
  143.         print(hex(Si[i][j])[2:],end=',')
  144.     print("")
  145. '''

AES ShiftRow

  1. '''
  2. # File : AES_ShiftRow.py
  3. # Author : Hongpei Lin
  4. # Date : 20191111
  5. # Purpose : In algorithm AES (Step 2)
  6. '''
  8. def ShiftRow_Left_One(S):
  9.     temp=S[0]
  10.     for i in range(len(S)-1):
  11.         S[i]=S[i+1]
  12.     S[len(S)-1]=temp
  13.     return S
  15. def ShiftRow_Left_All(S):
  16.     for i in range(len(S)):
  17.         for j in range(i):
  18.             S[i]=ShiftRow_Left_One(S[i])
  19.     return S
  21. '''
  22. Stest=[[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]]
  23. Stest=ShiftRow_Right_All(Stest)
  26. for i in range(len(Stest)):
  27.     for j in range(len(Stest[0])):
  28.         print(Stest[i][j],end=",")
  29.     print("")
  30. '''

AES MixColunm

  1. '''
  2. # File : AES_MixColunm.py
  3. # Author : Hongpei Lin
  4. # Date : 20191113
  5. # Purpose : In algorithm AES (Step 3)
  6. '''
  7. import AES_Box
  8. Mixcolumn=[[2,3,1,1],
  9.            [1,2,3,1],
  10.            [1,1,2,3],
  11.            [3,1,1,2]]
  13. #Multiply two matrix in GF(2^8)
  14. #matrix a and b have same rank, and thay are normal matrix, meaning row=colunm
  15. def Matrix_Mul(a,b):
  16.     row=len(a)
  17.     c=[[0,0,0,0] for i in range(4)]
  18.     for i in range(row):
  19.         for j in range(row):#row=colunm
  20.             k=0
  21.             while k<row:
  22.                 c[i][j]=c[i][j]^(AES_Box.mul(a[i][k],b[k][j]))
  23.                 k+=1
  24.     return c
  26. '''
  27. examplem=[[int('87',16),int('f2',16),int('4d',16),int('97',16)],
  28.           [int('6e', 16),int('4c',16),int('90',16),int('ec',16)],
  29.           [int('46',16),int('e7',16),int('4a',16),int('c3',16)],
  30.           [int('a6',16),int('8c',16),int('d8',16),int('95',16)]]
  32. test_mixcolunm=Matrix_Mul(Mixcolunm,examplem)
  33. for i in range(4):
  34.     for j in range(4):
  35.         print(hex(test_mixcolunm[i][j])[2:],end=',')
  36.     print("")
  37. '''

AES RoundKey

AES Generate key and counter

  1. '''
  2. # File : AES_KeyAndCounter.py
  3. # Author : Hongpei Lin
  4. # Date : 20191113
  5. # Purpose : In algorithm AES (Step 4)
  6. '''
  7. import codecs
  8. import random
  10. def BuildRandomKey(n):
  11.     number=str(random.randint(0,1))
  12.     while n-1:
  13.         number=number+str(random.randint(0,1))
  14.         n=n-1
  15.     return number
  18. #generate Key
  19. fk=codecs.open("Key.txt","w")
  20. fk.write(BuildRandomKey(128))
  21. fk.close()
  23. #generate counter
  24. fc=codecs.open("Counter.txt","w")
  25. fc.write(BuildRandomKey(128))
  26. fc.close()

AddRoundKey

  1. '''
  2. # File : AES_AddRoundKey.py
  3. # Author : Hongpei Lin
  4. # Date : 20191113
  5. # Purpose : In algorithm AES (Step 4)
  6. '''
  7. import codecs
  8. import AES_ShiftRow
  9. import AES_Box
  10. fo=codecs.open("Key.txt","r")
  11. KEY=fo.read()
  12. fo.close()
  14. #Zero round KEY,4*4 matrix,return string type
  15. key0=[[0,0,0,0] for i in range(4)]
  16. KEY_Index=0
  17. for i in range(len(key0)):
  18.     for j in range(len(key0[0])):
  19.         key0[i][j]=KEY[KEY_Index:KEY_Index+8]
  20.         KEY_Index+=8
  22. RC=[1,2,4,8,16,32,64,128,int('1b',16),int('36',16)]
  24. #g function in AES step 4, w have 4 value,value's type is string(32 bits)
  25. #return string type(32 bits)
  26. def g_function(W,KeyRound):
  27.     B=[]
  28.     index=0
  29.     while index<len(W):#4 times
  30.         B.append(W[index:index+8])
  31.         index+=8
  32.     B=AES_ShiftRow.ShiftRow_Left_One(B)
  33.     for i in range(len(B)):
  34.         B[i]=AES_Box.SubByte(AES_Box.S1,int(B[i],2))#type=number
  35.     B[0]=B[0]^RC[KeyRound]
  36.     reslut=""
  37.     for i in B:
  38.         reslut+="{:08b}".format(i)
  39.     return reslut#string type
  41. w=[0 for i in range(4)]#subkey
  43. #w0-w3,w is string type
  44. for i in range(len(key0)):
  45.     temp=""
  46.     for j in range(len(key0[0])):
  47.         temp+=key0[j][i]
  48.     w[i]=temp
  50. #Generate all the Key,output string type
  51. def build_subkey(W,KeyRoundTotal):
  52.     time=0
  53.     while time<KeyRoundTotal:
  54.         Wg=g_function(W[-1],time)
  55.         W_new=int(Wg,2)^int(W[len(W)-4],2)
  56.         W_new=bin(W_new)[2:]
  57.         while not len(W_new)==32:#高位填充
  58.             W_new="0"+W_new
  59.         W.append(W_new)
  60.         for i in range(3):
  61.             temp=int(W[-1],2)^int(W[len(W)-4],2)
  62.             temp=bin(temp)[2:]
  63.             while not len(temp)==32:
  64.                 temp="0"+temp
  65.             W.append(temp)
  66.         time+=1
  67.     return W
  69. #w_test=['00001111000101010111000111001001','01000111110110011110100001011001','00001100101101111010110111010110','10101111011111110110011110011000']
  70. W_key=build_subkey(w,10)
  72. #input strings state and key, both are 128bits
  73. #output encripttext , string type, 128bits
  74. def AddRoundKey(state,key):
  75.     state_matrix=[[0,0,0,0] for i in range(4)]
  76.     key_matrix=[[0,0,0,0] for i in range(4)]
  77.     result_matrix=[[0,0,0,0] for i in range(4)]
  78.     result_string=""
  79.     string_index=0
  81.     for i in range(4):
  82.         for j in range(4):
  83.             #change srtring to number, to compute
  84.             state_matrix[i][j]=int(state[string_index:string_index+8],2)
  85.             key_matrix[i][j]=int(key[string_index:string_index+8],2)
  87.             #XOR ,and change the reslut to string type,every value has 8 bits
  88.             result_matrix[i][j]=key_matrix[i][j]^state_matrix[i][j]
  89.             result_matrix[i][j]="{:08b}".format(result_matrix[i][j])
  90.             result_string=result_string+result_matrix[i][j]
  91.             string_index+=8
  93.     return result_string
  94. '''
  95. for i in range(4):
  96.     for j in range(4):
  97.         print(W_key[i][j],end=',')
  98.     print("")
  99. '''

AES CTR

  1. '''
  2. # File : AES_CTR.py
  3. # Author : Hongpei Lin
  4. # Date : 20191113
  5. # Purpose : AES CTR
  6. '''
  7. import codecs
  8. import AES_Box
  9. import AES_ShiftRow
  10. import AES_MixColumn
  11. import AES_AddRoundKey
  12. import random
  13. import re
  14. #make a string become bitstream
  15. def Str_to_Byte(s):
  16.     news=""
  17.     for i in s:
  18.         news=news+"{:08b}".format(ord(i))
  19.     return news
  21. #block the plaintext, every block have 128 bits
  22. #output list type, list's value is string(128 bits)
  23. #first value is stuffing bits counts.
  24. def Block_P(Plainfile):
  25.     #read the file
  26.     fo=codecs.open(Plainfile,"r",encoding='utf-8')
  27.     Plaintext=fo.read()
  28.     fo.close()
  30.     Block=[]
  31.     Plaintext=Str_to_Byte(Plaintext)
  32.     PlainLength=len(Plaintext)
  34.     #Byte stuffing counts, locat in lowest byte
  35.     stufy_bit=128-PlainLength%128
  36.     stufy_bit_str=AES_Box.SubByte(AES_Box.S1,stufy_bit)#use S-Box subbyte the number
  37.     stufy_bit_str="{:08b}".format(stufy_bit_str)
  38.     temp=""
  39.     for i in range(120):
  40.         temp=temp+str(random.randint(0,1))
  41.     stufy_bit_str=temp+stufy_bit_str
  43.     Block.append(stufy_bit_str)
  45.     zero=""
  46.     while stufy_bit:
  47.         zero=zero+str(random.randint(0,1))
  48.         stufy_bit-=1
  49.     Plaintext=zero+Plaintext
  51.     #stufy_bit=plaintext's index=0
  52.     while stufy_bit<len(Plaintext):
  53.         Block.append(Plaintext[stufy_bit:stufy_bit+128])
  54.         stufy_bit+=128
  55.     return Block
  57. #Counter is a 128 bits's string
  58. #output 128 bits string
  59. def CTR(Counter):
  60.     # build state matrix,type is string
  61.     state=[[0,0,0,0] for i in range(4)]
  62.     Index=0
  64.     for i in range(len(state)):
  65.         for j in range(len(state[0])):
  66.             state[i][j]=Counter[Index:Index+8]
  67.             Index+=8
  69.     #Step1:SubByte
  70.     for i in range(len(state)):
  71.         for j in range(len(state[0])):
  72.             state[i][j]=AES_Box.SubByte(AES_Box.S1,int(state[i][j],2))#return int type
  73.             state[i][j]='{:08b}'.format(state[i][j])
  75.     #Step2:ShiftRow
  76.     state=AES_ShiftRow.ShiftRow_Left_All(state)
  78.     #Step3:MixColunm
  79.     for i in range(len(state)):
  80.         for j in range(len(state[0])):
  81.             state[i][j]=int(state[i][j],2)
  82.     state=AES_MixColumn.Matrix_Mul(AES_MixColumn.Mixcolumn,state)
  83.     for i in range(len(state)):
  84.         for j in range(len(state[0])):
  85.             state[i][j]="{:08b}".format(state[i][j])
  87.     #Step4:AddRoundKey,10 rounds
  88.     counter_string=""
  89.     #change matrix to string
  90.     for i in range(len(state)):
  91.         for j in range(len(state[0])):
  92.             counter_string=counter_string+state[i][j]
  94.     for i in range(10):
  95.         Temp_Key=""
  96.         for j in range(4):
  97.             Temp_Key+=AES_AddRoundKey.W_key[(i+1)*4+j]
  98.         counter_string=AES_AddRoundKey.AddRoundKey(counter_string,Temp_Key)#W_key from [4:44]
  100.     return counter_string
  102. #Encrypt function,input filename
  103. def AES_Encrypt(filename,counter):
  104.     Block_Text=Block_P(filename)
  105.     C=[]#encrypttext,string type
  107.     for i in Block_Text:
  108.         C.append(int(i,2)^int(counter,2))
  109.         counter=bin(int(counter,2)+1)[2:]
  111.     #bit stuffing
  112.     #every block text
  113.     for i in range(len(C)):
  114.         C[i]=bin(C[i])[2:]#string type
  115.         zero=""
  116.         stuffingLength=128-len(C[i])
  118.         while stuffingLength:
  119.             zero=zero+"0"
  120.             stuffingLength-=1
  121.         C[i]=zero+C[i]
  123.     #encode
  124.     writetext=""
  125.     for i in C:
  126.         s=re.findall(r".{8}",i)
  127.         for j in s:
  128.             writetext+=chr(int(j,2))
  130.     #print(len(writetext[1:]))
  132.     fw=codecs.open("AESEncryptText.txt","w",encoding='utf-8')
  133.     fw.write(writetext)
  134.     fw.close()
  136.     return True
  138. #Decrypt function,input filename
  139. def AES_Decrypt(filename,counter):
  141.     fr=codecs.open(filename,"r",encoding='utf-8')
  142.     Block_Text=fr.read()
  143.     fr.close()
  145.     Block_bitstream=Str_to_Byte(Block_Text)
  147.     P=[]
  148.     Text_Index=0
  149.     while Text_Index<len(Block_bitstream):
  150.         P.append(Block_bitstream[Text_Index:Text_Index+128])
  151.         Text_Index+=128
  153.     #Decrypt
  154.     for i in range(len(P)):
  155.         P[i]=bin(int(counter,2)^int(P[i],2))[2:]
  156.         counter = bin(int(counter, 2) + 1)[2:]
  159.     for i in range(len(P)):
  160.         stuffing_bit=128-len(P[i])
  161.         zero=""
  162.         while stuffing_bit:
  163.             zero+="0"
  164.             stuffing_bit-=1
  165.         P[i]=zero+P[i]
  167.     stufy_bit=AES_Box.SubByte(AES_Box.Si,int(P[0][-8:],2))# int type
  169.     Plain_Stream=""
  170.     for i in P[1:]:
  171.         Plain_Stream=Plain_Stream+i
  172.     Plain_Stream=Plain_Stream[stufy_bit:]#delete stuffing bits
  174.     #change bitstream to string(code)
  175.     Plain_Text=""
  176.     s=re.findall(r".{8}",Plain_Stream)
  177.     for j in s:
  178.         Plain_Text+=chr(int(j, 2))
  180.     fw=codecs.open("AESDecryptText.txt","w",encoding='utf-8')
  181.     fw.write(Plain_Text)
  182.     fw.close()
  184.     return True

AES CMD Program

  1. '''
  2. # File : AES_CMD.py
  3. # Author : Hongpei Lin
  4. # Date : 20191119
  5. # Purpose : AES CMD program, running it in CMD view
  6. '''
  7. import sys
  8. import getopt
  9. import AES_CTR
  10. import codecs
  12. def __main__(argv):
  14.     fcr = codecs.open("Counter.txt", "r", encoding='utf-8')
  15.     counter = fcr.read()
  16.     fcr.close()
  18.     try:
  19.         opts,args=getopt.getopt(argv,"he:d:",["help","encrypt=","decrypt="])
  20.     except getopt.GetoptError:
  21.         print("ERROR:AES_CMD.py -e <filename> \n   or:AES_CMD.py -d <filename>")
  22.         print("   or:AES_CMD.py --encrypt=<filename> \n   or:AES_CMD.py --decrypt=<filename>")
  23.         sys.exit(2)
  25.     for opt,arg in opts:
  26.         if opt in ("-h","--help"):
  27.             print("Please input in these format")
  28.             print("AES_CMD.py -e <filename>\nAES_CMD.py -d <filename>")
  29.             print("AES_CMD.py --encrypt=<filename>\nAES_CMD.py --decrypt=<filename>")
  30.             sys.exit()
  31.         elif opt in ("-e","--encrypt"):
  32.             counter=AES_CTR.CTR(counter)
  33.             filename=arg
  34.             if AES_CTR.AES_Encrypt(filename,counter):
  35.                 print("Encrypt Successfully! Wrote the CryptText in AESEncryptText.txt")
  36.         elif opt in ("-d","--decrypt"):
  37.             counter=AES_CTR.CTR(counter)
  38.             filename=arg
  39.             if AES_CTR.AES_Decrypt(filename,counter):
  40.                 print("Decrypt Successfully! Wrote the PlainText in AESDecryptText.txt")
  42. if __name__=="__main__":
  43.     __main__(sys.argv[1:])
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