#include<iostream> #include<bitset> #include<string> using namespace std; int IPTable[64] = { 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 }; int CPTable[48] = { 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 }; int SiftTable[16] = { 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 }; int EPTable[48] = { 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 }; int SBoxTable[8][4][16] = { { 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 } }; int PBoxTable[32]={ 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 }; int FinalTable[64] = { 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 }; void print64BitStream(bitset<64> temp) { for(int i = 0;i<temp.size();i++) cout<<temp[i]; cout<<endl; } void print56BitStream(bitset<56> temp) { for(int i = 0;i<temp.size();i++) cout<<temp[i]; cout<<endl; } void print32BitStream(bitset<32> temp) { for(int i = 0;i<temp.size();i++) cout<<temp[i]; cout<<endl; } void print48BitStream(bitset<48> temp) { for(int i = 0;i<temp.size();i++) cout<<temp[i]; cout<<endl; } bitset<64> reverse(bitset<64> temp) { bitset<64> reverseVal(0); for(int i=0;i<64;i++) reverseVal[i] = temp[63-i]; return reverseVal; } void InitialPermutation(bitset<64> &temp) { //copy bitset<64> bitset<64> BitSetCopy(0); for(int j=0;j<64;j++) { BitSetCopy[j] = temp[j]; } for(int i=0;i<64;i++)//IP 置换 !!! { temp[i] = BitSetCopy[IPTable[i]-1]; } } bitset<48> CompressionPermutation(bitset<56> temp) { bitset<48> CPKey(0); for(int i = 0;i<48;i++) { CPKey[i] = temp[CPTable[i]-1]; } return CPKey; } bitset<48> ExpansionPermutation(bitset<32> temp) { bitset<48> EPCipher(0); for(int i=0;i<48;i++) EPCipher[i] = temp[EPTable[i]-1]; return EPCipher; } bitset<32> SubstitutionBox(bitset<48> key,bitset<48> RPT) { //XOR operation bitset<48> AfterXOR(0); AfterXOR = key^RPT; //SBox bitset<2> temp2Bit(0); bitset<4> temp4Bit(0); bitset<32> resultVal(0); bitset<4> output[8]; bitset<6> input[8]; for(int i=0,j=0;i<48;i++) { input[j][i-j*6] = AfterXOR[i]; if((i+1)%6==0) { j++; } } for(int i=0;i<8;i++) { for(int j=0;j<6;j++) { if(j==0) temp2Bit[1] = input[i][j]; else if(j==5) temp2Bit[0] = input[i][j]; else temp4Bit[4-j] = input[i][j]; } output[i] = SBoxTable[i][temp2Bit.to_ulong()][temp4Bit.to_ulong()];//!!!!!! //if(i==0)cout<<"output: "<<output[i]<<endl; for(int l=0;l<4;l++) { resultVal[i*4+l] = output[i][3-l]; } } cout<<"SBox Output: "; print32BitStream(resultVal); return resultVal; }//!!!!!!!!!!! bitset<32> PBoxPermutation(bitset<32> temp) { bitset<32> returnVal(0); for(int i=0;i<32;i++) { returnVal[i] = temp[PBoxTable[i]-1]; } return returnVal; } void equalTo(bitset<32>&a,bitset<32>b) { for(int i=0;i<32;i++) { a[i] = b[i]; } } bitset<56> cutKey(bitset<64> &temp) { bitset<56> tempTo56(0); for(int i = 0,k = 0;i<64;i++) { //64 To 58 if((i+1)%8!=0) { tempTo56[k++] = temp[i]; } } return tempTo56; } void siftKey(bitset<56> &temp,int round) { bitset<28> LPT(0); bitset<28> RPT(0); int LPTtempVal[2]; int RPTtempVal[2]; int siftValue = SiftTable[round];//获得移位的值 循环左移。。 for(int i=0;i<56;i++) { if(i<28) { LPT[i] = temp[i]; } else { RPT[i-28] = temp[i]; } } for(int i=0;i<siftValue;i++) { LPTtempVal[i] = LPT[i]; RPTtempVal[i] = RPT[i]; } //移位操作 LPT = (LPT.to_ulong())>>siftValue; RPT = (RPT.to_ulong())>>siftValue; for(int k = siftValue,i=28-k,j=0;k>0;k--,j++) { LPT[i] = LPTtempVal[j]; RPT[i] = RPTtempVal[j]; } for(int i=0;i<56;i++) { if(i<28) { temp[i] = LPT[i]; } else { temp[i] = RPT[i-28]; } } } bitset<48> getKey(bitset<64> initKey,int round)//cut-->CP { bitset<48> CPfinalKey(0); bitset<56> CutKey = cutKey(initKey); siftKey(CutKey,round); //after sifting for(int i =0;i<48;i++) { CPfinalKey[i] = CutKey[CPTable[i]-1]; } return CPfinalKey; } bitset<64> FinalPermutation(bitset<64> temp) { bitset<64> returnVal(0); for(int i=0;i<64;i++) { returnVal[i] = temp[FinalTable[i]-1]; } return returnVal; } bitset<64> De_FinalPermutation(bitset<64> temp) { bitset<64>returnVal(0); for(int i=0;i<64;i++) { returnVal[FinalTable[i]-1] = temp[i]; } return returnVal; } bitset<64> DESDecode(bitset<64>EncodeVal,bitset<64>Key) { InitialPermutation(EncodeVal); bitset<32> RPT; bitset<32> LPT; bitset<32> tempPT; bitset<64> finalResult; bitset<48> ExpRPT(0); for(int i=0;i<64;i++) { if(i<32) LPT[i] = EncodeVal[i]; else RPT[i-32] = EncodeVal[i]; //plain text initial finish. } bitset<48> theKey(0); for(int i=15;i>=0;i--) { theKey = getKey(Key,i); //Key Finish cout<<i<<".Key:"<<theKey<<endl; cout<<i<<".RPT:"; print32BitStream(RPT); //Expnasion Permutation 48bit ExpRPT = ExpansionPermutation(RPT); tempPT = (PBoxPermutation(SubstitutionBox(theKey,ExpRPT)))^LPT; LPT = RPT; RPT = tempPT; } cout<<"Final LPT: "; print32BitStream(LPT); cout<<"Final RPT: "; print32BitStream(RPT); for(int i=0;i<64;i++) { if(i<32) finalResult[i] = LPT[i]; else finalResult[i] = RPT[i-32]; } finalResult = FinalPermutation(finalResult); return finalResult; } bitset<64> DESEncode(bitset<64>PlainText,bitset<64>Key) { InitialPermutation(PlainText); bitset<32> RPT; bitset<32> LPT; bitset<32> tempPT; bitset<64> finalResult; bitset<48> ExpRPT(0); for(int i=0;i<64;i++) { if(i<32) LPT[i] = PlainText[i]; else RPT[i-32] = PlainText[i]; //plain text initial finish. } bitset<48> theKey(0); for(int i=0;i<16;i++) { theKey = getKey(Key,i); //Key Finish cout<<i<<".Key:"<<theKey<<endl; cout<<i<<".RPT:"; print32BitStream(RPT); //Expnasion Permutation 48bit ExpRPT = ExpansionPermutation(RPT); tempPT = (PBoxPermutation(SubstitutionBox(theKey,ExpRPT)))^LPT; LPT = RPT; RPT = tempPT; } cout<<"Final LPT: "; print32BitStream(LPT); cout<<"Final RPT: "; print32BitStream(RPT); for(int i=0;i<64;i++) { if(i<32) finalResult[i] = RPT[i]; else finalResult[i] = LPT[i-32]; } finalResult = FinalPermutation(finalResult); return finalResult; } int main() { bitset<64> data(0); bitset<64> key(0); print64BitStream(DESEncode(data,key)); print64BitStream(DESDecode(DESEncode(data,key),key)); /* cout<<"PlainText:"; print64BitStream(data); cout<<"Key:"; print64BitStream(key); cout<<DESEncode(data,key)<<endl;*/ }
主要注意点:bitset的高位是在左边的.而DES的高位是在右边的.在进行to_ulong的时候需要确定是否倒置了否则可能造成错误.
DES的解密很简单.和加密步骤基本一致,但是需要把key的获取从第16轮开始获取直到第1轮的key.