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;
}
