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#include <math.h>#include <stdlib.h>#include <string.h>#include "bit.h"#include "encrypt.h" static const int DesTransform[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, 4}; *****************************************************************************/static const int DesRotations[16] = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}; static const int DesPermuted[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}; static const int DesInitial[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}; static const int DesExpansion[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}; static const int DesSbox[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}, },}; static const int DesPbox[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}; static const int DesFinal[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}; typedef enum DesEorD_ {encipher, decipher} DesEorD; static void permute(unsigned char *bits, const int *mapping, int n) {unsigned char temp[8];int i; memset(temp, 0, (int)ceil(n / );for (i = 0; i < n; i++) bit_set(temp, i, bit_get(bits, mapping[i] - 1));memcpy(bits, temp, (int)ceil(n / );return;} static int des_main(const unsigned char *source, unsigned char *target, const unsigned char *key, DesEorD direction) {static unsigned char subkeys[16][7];unsigned char temp[8], lkey[4], rkey[4], lblk[6], rblk[6], fblk[6], xblk[6], sblk;int row, col, i, j, k, p; if (key != NULL) { memcpy(temp, key, ; permute(temp, DesTransform, 56); memset(lkey, 0, 4); memset(rkey, 0, 4); for (j = 0; j < 28; j++) bit_set(lkey, j, bit_get(temp, j)); for (j = 0; j < 28; j++) bit_set(rkey, j, bit_get(temp, j + 28)); for (i = 0; i < 16; i++) { bit_rot_left(lkey, 28, DesRotations[i]); bit_rot_left(rkey, 28, DesRotations[i]); for (j = 0; j < 28; j++) bit_set(subkeys[i], j, bit_get(lkey, j)); for (j = 0; j < 28; j++) bit_set(subkeys[i], j + 28, bit_get(rkey, j)); permute(subkeys[i], DesPermuted, 48); }} memcpy(temp, source, ; permute(temp, DesInitial, 64); memcpy(lblk, &temp[0], 4);memcpy(rblk, &temp[4], 4); for (i = 0; i < 16; i++) { memcpy(fblk, rblk, 4); permute(fblk, DesExpansion, 48); if (direction == encipher) { bit_xor(fblk, subkeys[i], xblk, 48); memcpy(fblk, xblk, 6); } else { bit_xor(fblk, subkeys[15 - i], xblk, 48); memcpy(fblk, xblk, 6); } p = 0; for (j = 0; j < 8; j++) { row = (bit_get(fblk, (j * 6)+0) * 2) + (bit_get(fblk, (j * 6)+5) * 1); col = (bit_get(fblk, (j * 6)+1) * + (bit_get(fblk, (j * 6)+2) * 4) + (bit_get(fblk, (j * 6)+3) * 2) + (bit_get(fblk, (j * 6)+4) * 1); sblk = (unsigned char)DesSbox[j][row][col]; for (k = 4; k < 8; k++) { bit_set(fblk, p, bit_get(&sblk, k)); p++; } } permute(fblk, DesPbox, 32); bit_xor(lblk, fblk, xblk, 32); memcpy(lblk, rblk, 4); memcpy(rblk, xblk, 4);} memcpy(&target[0], rblk, 4);memcpy(&target[4], lblk, 4); permute(target, DesFinal, 64);return 0;} void des_encipher(const unsigned char *plaintext, unsigned char *ciphertext, const unsigned char *key) {des_main(plaintext, ciphertext, key, encipher);return;} void des_decipher(const unsigned char *ciphertext, unsigned char *plaintext, const unsigned char *key) {des_main(ciphertext, plaintext, key, decipher);return;}
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