DES 구현 (C)

<Table.h>

#include <stdint.h>

unsigned static IP[64] =
{
    58, 50, 42, 34, 26, 18, 10, 2,
    60, 52, 44, 36, 28, 20, 12, 04,
    62, 54, 46, 38, 30, 22, 14, 06,
    64, 56, 48, 40, 32, 24, 16, 8,
    57, 49, 41, 33, 25, 17, 9,  1,
    59, 51, 43, 35, 27, 19, 11, 03,
    61, 53, 45, 37, 29, 21, 13, 05,
    63, 55, 47, 39, 31, 23, 15, 07
};


unsigned static FP[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
};

unsigned static ExpansionTable[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
};


unsigned static SBOX[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}
    }
};

unsigned static DBOX[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
};


unsigned static ParityTable[56] =
{
    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,
    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, 04
};

unsigned static CompressionTable[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
};

unsigned static Shifts[16] =
{
    1, 1, 2, 2, 2, 2, 2, 2,
    1, 2, 2, 2, 2, 2, 2, 1
};

 

<DES.c>

#include <stdio.h>
#include "Table.h"

unsigned long long InitialPermutation(unsigned long long plaintext)
{
    unsigned long long AIP = 0x00;
    for (int i = 0; i < 64; i++)
        AIP |= (((plaintext >> (64 - IP[i])) & 0x1) << (63 - i));
    
    return AIP;
}

unsigned long long RoundFunction(unsigned long long left, unsigned long long right, unsigned long long roundkey, int round)
{
    //Expansion
    unsigned long long AE = 0x00;
    for (int i = 0; i < 48; i++)
        AE |= (((right >> (32 - ExpansionTable[i]) & 0x1)) << (47 - i));
    
    //XOR with Key
    unsigned long long AXK = AE ^ roundkey;

    //S-Box
    unsigned long long tmp = 0x00;
    unsigned long long row = 0x00, col = 0x00;
    unsigned long long ASB = 0x00;
    
    for (int i = 0; i < 8; i++) {
        tmp = ((AXK >> (42 - 6 * i)) & 0x3f);
        row = (((tmp >> 5) << 1) | (tmp & 0x1));
        col = ((tmp & 0x1e) >> 1);
        ASB |= (SBOX[i][row][col] << (28 - 4 * i));
    }
    
    
    //D-BOX
    unsigned long long output = 0x00;
    for (int i = 0; i < 32; i++)
        output |= (((ASB >> (32 - DBOX[i])) & 0x1) << (31 - i));
    
    //XOR with Left
    unsigned long long AXL = output ^ left;

    return AXL;
}

unsigned long long KeyGeneration(unsigned long long key, unsigned long long round)
{
    unsigned long long APD = 0x00, left = 0x00, right = 0x00;
    unsigned long long roundkey[16] = { 0x00, };
    unsigned long long tmp[16] = { 0x00, };

    //Parity Drop
    for (int i = 0; i < 56; i++)
        APD |= (((key >> (64 - ParityTable[i])) & 0x1) << (55 - i));
    
    //Divide
    left = APD >> 28;
    right = APD & 0xfffffff;
    
    for (int i = 0; i < 16; i++) {
        //Shift
        left = (((left << Shifts[i]) & 0xfffffff) | (left >> (28 - Shifts[i])));
        right = (((right << Shifts[i]) & 0xfffffff) | (right >> (28 - Shifts[i])));

        //Integrate
        tmp[i] = ((left << 28) | right);
    }
    
    //Compression
    for (int i = 0; i < 48; i++)
        roundkey[round] |= (((tmp[round] >> (56 - CompressionTable[i])) & 0x1) << (47 - i));
    
    return roundkey[round];
}

unsigned long long FinalPermutation(unsigned long long ciphertext)
{
    unsigned long long AFP = 0x00;
    for (int i = 0; i < 64; i++)
        AFP |= (((ciphertext >> (64 - FP[i])) & 0x1) << (63 - i));
    
    return AFP;
}

int main()
{
    unsigned long long Plaintext = 0x00;
    unsigned long long Ciphertext = 0x00;
    unsigned long long Key = 0x00;
    unsigned long long afterIP = 0x00;
    unsigned long long left = 0x00;
    unsigned long long right = 0x00;
    unsigned long long tmp = 0x00;
    unsigned long long RoundKey[16] = { 0x00, };

    printf("====== DES ENCRYPTION =====\n");
    printf("Input Plaintext : ");
    scanf("%llx", &Plaintext);
    printf("    Input Key   : ");
    scanf("%llx", &Key);
    
    afterIP = InitialPermutation(Plaintext);

    left = (afterIP & 0xffffffff00000000) >> 32;
    right = afterIP & 0xffffffff;
    
    for (int k = 0; k < 16; k++)
        RoundKey[k] = KeyGeneration(Key, k);
    
    for (int r = 0; r < 16; r++) {
        left = RoundFunction(left, right, RoundKey[r], r);
        
        if (r != 15) {
            tmp = right;
            right = left;
            left = tmp;
        }
    }

    Ciphertext = ((left << 32) | right);
    Ciphertext = FinalPermutation(Ciphertext);
    
    printf("   Ciphertext   : %llx\n", Ciphertext);
    
    return 0;
}