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DES演算法 Python版本實現

#統一按照字串處理,輸入字串輸出也是字串。 def IP(Mingwen): assert len(Mingwen)==64 IPtable=[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] ret="" for i in IPtable: ret=ret+Mingwen[i-1
] return ret #迴圈左移位數 def shift(a,s): try: if len(a)>28: raise NameError except TypeError: pass a=a[s:]+a[0:s] return a def createSubkey(key): assert len(key)==64 Clist=[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] Dlist=[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] #初試生成 C0="" D0="" for i in Clist: C0+=key[i-1] for i in Dlist: D0+=key[i-1] assert len(C0)==28 assert len(D0)==28 Movetimes=[1,1,2,2,2,2,2,2,1,2,2,2,2,2
,2,1] retkey=[] 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] for i in range(0,16): C0=shift(C0,Movetimes[i]) D0=shift(D0,Movetimes[i]) temp=C0+D0 tempkey="" for i in PC_2: tempkey+=temp[i-1] assert len(tempkey)==48 retkey.append(tempkey) tempkey="" return retkey def Etuozhan(Rn): Elist=[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] retRn="" for i in Elist: retRn+=Rn[i-1] assert len(retRn)==48 return retRn 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)] Phezhihuan=[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] def S_sub(Ln,Rn,subkey,oldRn): tempresult=int(Rn,base=2)^int(subkey,base=2) tempresult=bin(tempresult)[2:] while len(tempresult)<48: tempresult="0"+tempresult index=0 retstr="" for list in S: hang=int(tempresult[index]+tempresult[index+5],base=2) lie=int(tempresult[index+1:index+5],base=2) a=bin(list[hang*16+lie])[2:] while len(a)<4: a="0"+a retstr+=a index+=6 assert len(retstr)==32 tmp="" for i in Phezhihuan: tmp+=retstr[i-1] a=int(tmp, base=2) ^ int(Ln, base=2) a=bin(a)[2:] while len(a)<32: a="0"+a assert len(a)==32 (Ln,Rn)=(oldRn,a) w5555555555=Ln+Rn return (Ln,Rn) def P_1(L16,R16): tmp=L16+R16 list=[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] retstr="" for i in list: retstr+=tmp[i-1] assert len(retstr)==64 return retstr if __name__=="__main__": key="0001001000110100010101100111100010010001001000110100010101100111" Mingwen= "1001100001110110010101000011001000010001010001110010010110000011" Chushizhihuan=IP(Mingwen) subkeylist=createSubkey(key) Ln=Chushizhihuan[0:32] Rn=Chushizhihuan[32:] for subkey in subkeylist: while len(Rn)<32: Rn="0"+Rn while len(Ln)<32: Ln="0"+Ln Rn_tuozhan=Etuozhan(Rn) (Ln,Rn)=S_sub(Ln,Rn_tuozhan,subkey,Rn) # print(hex(int(Ln+Rn,base=2))[2:].upper()) (Ln,Rn)=(Rn,Ln) b=P_1(Ln,Rn) print(hex(int(b,base=2)).upper())