void DES (const int32_t *keysArrayPtr, int32_t Count, char * encryptData,short mode) { EncryptBlk *EncryptDataPtr; EncryptBlk resultData; EncryptBlk *ReturnData; short swapCount; uint32_t fResult; uint32_t gTemp; uint32_t keyHi; uint32_t keyLo; uint32_t *keyPtr; EncryptDataPtr = (EncryptBlk *) encryptData; ReturnData = EncryptDataPtr; for ( ;Count > 0; Count -= kkeySize) { InitialPermutation(EncryptDataPtr, &resultData ); if (mode == kEncrypt) keyPtr = (uint32_t*)keysArrayPtr; else /* must be decrypt */ keyPtr = TheLastKey(keysArrayPtr); /* start at last key in array */ for (swapCount = knumKeys; swapCount != 0; swapCount--) { if (mode == kEncrypt) { keyHi = *keyPtr++; keyLo = *keyPtr++; } else /* must be decrypt */ { keyLo = *keyPtr--; keyHi = *keyPtr--; } fResult = FRK(resultData.keyLo,keyHi,keyLo); resultData.keyHi = resultData.keyHi ^ fResult; if (swapCount > 1) /* EXchange is multi-line macro and requires {}*/ { EXchange(resultData.keyHi,resultData.keyLo); } } EXchange(resultData.keyHi,resultData.keyLo); Permute(&resultData,(int32_t*)&N_IPInvTbl); EncryptDataPtr = (EncryptBlk *) (((char*) EncryptDataPtr) + kkeySize); } ReturnData->keyLo = htonl(resultData.keyLo); ReturnData->keyHi = htonl(resultData.keyHi); }
//Decryption Function int decryption(int cipher64Bit[], int pc1Output56BitKey[], int plainText[]) { int iteration = 0; int ipOutput64Bit[64]; int permutationChoiceMatrix2[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 leftKey28Bit[28]; int rightKey28Bit[28]; int shiftedLeftKey28Bit[28],shiftedRightKey28Bit[28],key56Bit[56],key48Bit[48]; int initialPermutationMatrix[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 leftN32Bit[32],rightN32Bit[32]; int inverseInitialPermutationMatrix[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}; int eBitSelectionMatrix[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 rightN48Bit[48],xorOutput48bit[48],sBoxOutput32bit[32]; int sBox1[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}}; int sBox2[4][16]={ {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}}; int sBox3[4][16]={ {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}}; int sBox4[4][16]={ {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}}; int sBox5[4][16]={ {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}}; int sBox6[4][16]={ {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}}; int sBox7[4][16]={ {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}}; int sBox8[4][16]={ {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 perMatrix[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 perMatrixOutput32bit[32]; int rightNOutput32bit[32]; int siftMode[16]={SHIFT_1,SHIFT_1, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_1, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_2, SHIFT_1}; int output64Bit[64]; int x=0,y=0,z=0; int key[16][48]; int keyIndex; //printArray(cipher, 64, "cipher"); //printArray(key64Bit, 64, "key64Bit"); //***********DECRYPTION IMPLEMENTATION STARTS FROM HERE*************// //16 keys calculation for(iteration= 0; iteration<16;iteration++) { //printf("\n Key : %d",iteration+1); //STEP 1 A divide56To28( pc1Output56BitKey,leftKey28Bit,rightKey28Bit); //printArray(leftKey28Bit, 28, "leftKey28Bit"); //printArray(rightKey28Bit, 28, "rightKey28Bit"); //STEP 1 B1 leftShift28(leftKey28Bit,shiftedLeftKey28Bit,siftMode[iteration]); //printArray(shiftedLeftKey28Bit, 28, "shiftedLeftKey28Bit"); //STEP 1 B2 leftShift28(rightKey28Bit,shiftedRightKey28Bit,siftMode[iteration]); //printArray(shiftedRightKey28Bit, 28, "shiftedRightKey28Bit"); //STEP 1 C concatenate28To56(shiftedLeftKey28Bit, shiftedRightKey28Bit, key56Bit); //printArray(key56Bit, 56, "key56Bit"); for(y=0;y<56;y++) { pc1Output56BitKey[y]=key56Bit[y]; } //STEP 1 D permutedChoice2( permutationChoiceMatrix2, key56Bit, key48Bit); //printArray(key48Bit, 48, "key48Bit"); for(z=0;z<48;z++) { key[iteration][z] = key48Bit[z]; } } //STEP 2 InitialPermutation(initialPermutationMatrix,cipher64Bit, ipOutput64Bit); //printArray(ipOutput64Bit,64, "ipOutput64Bit"); //STEP 3 divide64To32(ipOutput64Bit,leftN32Bit,rightN32Bit); //printArray(leftN32Bit, 32, "leftN32Bit"); //printArray(rightN32Bit, 32, "rightN32Bit"); for(iteration= 0,keyIndex=15; iteration<16;iteration++,keyIndex--) { //printf("\n Iteration : %d",iteration+1); //STEP 4 E eBitSelection( eBitSelectionMatrix, rightN32Bit, rightN48Bit); //printArray(rightN48Bit, 48, "rightN48Bit"); //STEP 4 F XOR48bit(rightN48Bit, key[keyIndex], xorOutput48bit); //printArray(xorOutput48bit, 48, "xorOutput48bit"); //STEP 4 G sBoxSelection( sBox1, sBox2, sBox3, sBox4, sBox5, sBox6, sBox7, sBox8, xorOutput48bit, sBoxOutput32bit); //printArray(sBoxOutput32bit, 32, "sBoxOutput32bit"); //STEP 4 H functionPermutationSelection( perMatrix, sBoxOutput32bit, perMatrixOutput32bit); //printArray(perMatrixOutput32bit, 32, "perMatrixOutput32bit"); //STEP 4 I rightN( leftN32Bit, perMatrixOutput32bit, rightNOutput32bit); //printArray(rightNOutput32bit, 32, "rightNOutput32bit"); if(iteration<=14) { //STEP 4 J for(x=0;x<32;x++) { leftN32Bit[x]=rightN32Bit[x]; } //printArray(leftN32Bit, 32, "leftN32Bit"); //STEP 4 K for(x=0;x<32;x++) { rightN32Bit[x]=rightNOutput32bit[x]; } //printArray(rightN32Bit, 32, "rightN32Bit"); } else { for(x=0;x<32;x++) { leftN32Bit[x]=rightNOutput32bit[x]; } //printArray(leftN32Bit, 32, "leftN32Bit"); } } //STEP 5 concatenate32To64(leftN32Bit, rightN32Bit, output64Bit); //printArray(output64Bit,64, "output64Bit"); //STEP 6 inverseInitialPermutation(inverseInitialPermutationMatrix,output64Bit, plainText); //printArray(plainText,64, "plainText"); return 0; }