DES Encryption and Decryption (Data Encryption Standard)
c:
// Rename this file DES.H////////////////////////////////////////////////////////////////////////// DES Encryption and Decryption// from efgh.com/softwareconst int DES_KEY_SIZE = 56;const int DES_DATA_SIZE = 64;const int DES_SBUFFER_SIZE = 48;const int DES_ROUNDS = 16;#ifdef TRIPLEDES class triple_des;#endifclass des{ private: const char *xmix(const char *, unsigned char [DES_DATA_SIZE], const unsigned char [DES_KEY_SIZE]); void encrypt_decrypt(unsigned char [DES_DATA_SIZE], int /* boolean */); unsigned char compressed_shifted_key[DES_ROUNDS][DES_SBUFFER_SIZE]; public: void initialize(const unsigned char[DES_KEY_SIZE]); void password(const char *); void encrypt(unsigned char data[DES_DATA_SIZE]) { encrypt_decrypt(data, 1 /* true */); } void decrypt(unsigned char data[DES_DATA_SIZE]) { encrypt_decrypt(data, 0 /* false */); } friend triple_des;};#ifdef TRIPLEDESclass triple_des{ private: des part[3]; void encrypt_decrypt(unsigned char [DES_DATA_SIZE], int /* boolean */); public: void initialize(const unsigned char key[3*DES_KEY_SIZE]) { part[0].initialize(key); part[1].initialize(key + DES_KEY_SIZE); part[2].initialize(key + 2*DES_KEY_SIZE); } void password(const char *); void encrypt(unsigned char data[DES_DATA_SIZE]) { part[0].encrypt(data); part[1].decrypt(data); part[2].encrypt(data); } void decrypt(unsigned char data[DES_DATA_SIZE]) { part[2].decrypt(data); part[1].encrypt(data); part[0].decrypt(data); }};#endif////////////////////////////////////////////////////////////////////////// Rename this file DES.CPP////////////////////////////////////////////////////////////////////////// DES Encryption and Decryption// from efgh.com/software#include <mem.h>#include "des.h"typedef unsigned long DWORD;const int KEY_SHIFT[DES_ROUNDS] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};const unsigned char COMPRESSION_PERMUTATION[DES_SBUFFER_SIZE] ={ 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};const unsigned char EXPANSION_PERMUTATION[DES_SBUFFER_SIZE] ={ 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};/* S-Boxes: 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 */// The following are the above S-boxes, packed one bit per byte:const unsigned char MODIFIED_SBOX_1[4*64] ={ 1,1,1,0,0,1,0,0,1,1,0,1,0,0,0,1,0,0,1,0,1,1,1,1,1,0,1,1,1,0,0,0, 0,0,1,1,1,0,1,0,0,1,1,0,1,1,0,0,0,1,0,1,1,0,0,1,0,0,0,0,0,1,1,1, 0,0,0,0,1,1,1,1,0,1,1,1,0,1,0,0,1,1,1,0,0,0,1,0,1,1,0,1,0,0,0,1, 1,0,1,0,0,1,1,0,1,1,0,0,1,0,1,1,1,0,0,1,0,1,0,1,0,0,1,1,1,0,0,0, 0,1,0,0,0,0,0,1,1,1,1,0,1,0,0,0,1,1,0,1,0,1,1,0,0,0,1,0,1,0,1,1, 1,1,1,1,1,1,0,0,1,0,0,1,0,1,1,1,0,0,1,1,1,0,1,0,0,1,0,1,0,0,0,0, 1,1,1,1,1,1,0,0,1,0,0,0,0,0,1,0,0,1,0,0,1,0,0,1,0,0,0,1,0,1,1,1, 0,1,0,1,1,0,1,1,0,0,1,1,1,1,1,0,1,0,1,0,0,0,0,0,0,1,1,0,1,1,0,1};const unsigned char MODIFIED_SBOX_2[4*64] ={ 1,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0,0,1,1,0,1,0,1,1,0,0,1,1,0,1,0,0, 1,0,0,1,0,1,1,1,0,0,1,0,1,1,0,1,1,1,0,0,0,0,0,0,0,1,0,1,1,0,1,0, 0,0,1,1,1,1,0,1,0,1,0,0,0,1,1,1,1,1,1,1,0,0,1,0,1,0,0,0,1,1,1,0, 1,1,0,0,0,0,0,0,0,0,0,1,1,0,1,0,0,1,1,0,1,0,0,1,1,0,1,1,0,1,0,1, 0,0,0,0,1,1,1,0,0,1,1,1,1,0,1,1,1,0,1,0,0,1,0,0,1,1,0,1,0,0,0,1, 0,1,0,1,1,0,0,0,1,1,0,0,0,1,1,0,1,0,0,1,0,0,1,1,0,0,1,0,1,1,1,1, 1,1,0,1,1,0,0,0,1,0,1,0,0,0,0,1,0,0,1,1,1,1,1,1,0,1,0,0,0,0,1,0, 1,0,1,1,0,1,1,0,0,1,1,1,1,1,0,0,0,0,0,0,0,1,0,1,1,1,1,0,1,0,0,1};const unsigned char MODIFIED_SBOX_3[4*64] ={ 1,0,1,0,0,0,0,0,1,0,0,1,1,1,1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1, 0,0,0,1,1,1,0,1,1,1,0,0,0,1,1,1,1,0,1,1,0,1,0,0,0,0,1,0,1,0,0,0, 1,1,0,1,0,1,1,1,0,0,0,0,1,0,0,1,0,0,1,1,0,1,0,0,0,1,1,0,1,0,1,0, 0,0,1,0,1,0,0,0,0,1,0,1,1,1,1,0,1,1,0,0,1,0,1,1,1,1,1,1,0,0,0,1, 1,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,1,0,0,0,1,1,1,1,0,0,1,1,0,0,0,0, 1,0,1,1,0,0,0,1,0,0,1,0,1,1,0,0,0,1,0,1,1,0,1,0,1,1,1,0,0,1,1,1, 0,0,0,1,1,0,1,0,1,1,0,1,0,0,0,0,0,1,1,0,1,0,0,1,1,0,0,0,0,1,1,1, 0,1,0,0,1,1,1,1,1,1,1,0,0,0,1,1,1,0,1,1,0,1,0,1,0,0,1,0,1,1,0,0};const unsigned char MODIFIED_SBOX_4[4*64] ={ 0,1,1,1,1,1,0,1,1,1,1,0,0,0,1,1,0,0,0,0,0,1,1,0,1,0,0,1,1,0,1,0, 0,0,0,1,0,0,1,0,1,0,0,0,0,1,0,1,1,0,1,1,1,1,0,0,0,1,0,0,1,1,1,1, 1,1,0,1,1,0,0,0,1,0,1,1,0,1,0,1,0,1,1,0,1,1,1,1,0,0,0,0,0,0,1,1, 0,1,0,0,0,1,1,1,0,0,1,0,1,1,0,0,0,0,0,1,1,0,1,0,1,1,1,0,1,0,0,1, 1,0,1,0,0,1,1,0,1,0,0,1,0,0,0,0,1,1,0,0,1,0,1,1,0,1,1,1,1,1,0,1, 1,1,1,1,0,0,0,1,0,0,1,1,1,1,1,0,0,1,0,1,0,0,1,0,1,0,0,0,0,1,0,0, 0,0,1,1,1,1,1,1,0,0,0,0,0,1,1,0,1,0,1,0,0,0,0,1,1,1,0,1,1,0,0,0, 1,0,0,1,0,1,0,0,0,1,0,1,1,0,1,1,1,1,0,0,0,1,1,1,0,0,1,0,1,1,1,0};const unsigned char MODIFIED_SBOX_5[4*64] ={ 0,0,1,0,1,1,0,0,0,1,0,0,0,0,0,1,0,1,1,1,1,0,1,0,1,0,1,1,0,1,1,0, 1,0,0,0,0,1,0,1,0,0,1,1,1,1,1,1,1,1,0,1,0,0,0,0,1,1,1,0,1,0,0,1, 1,1,1,0,1,0,1,1,0,0,1,0,1,1,0,0,0,1,0,0,0,1,1,1,1,1,0,1,0,0,0,1, 0,1,0,1,0,0,0,0,1,1,1,1,1,0,1,0,0,0,1,1,1,0,0,1,1,0,0,0,0,1,1,0, 0,1,0,0,0,0,1,0,0,0,0,1,1,0,1,1,1,0,1,0,1,1,0,1,0,1,1,1,1,0,0,0, 1,1,1,1,1,0,0,1,1,1,0,0,0,1,0,1,0,1,1,0,0,0,1,1,0,0,0,0,1,1,1,0, 1,0,1,1,1,0,0,0,1,1,0,0,0,1,1,1,0,0,0,1,1,1,1,0,0,0,1,0,1,1,0,1, 0,1,1,0,1,1,1,1,0,0,0,0,1,0,0,1,1,0,1,0,0,1,0,0,0,1,0,1,0,0,1,1};const unsigned char MODIFIED_SBOX_6[4*64] ={ 1,1,0,0,0,0,0,1,1,0,1,0,1,1,1,1,1,0,0,1,0,0,1,0,0,1,1,0,1,0,0,0, 0,0,0,0,1,1,0,1,0,0,1,1,0,1,0,0,1,1,1,0,0,1,1,1,0,1,0,1,1,0,1,1, 1,0,1,0,1,1,1,1,0,1,0,0,0,0,1,0,0,1,1,1,1,1,0,0,1,0,0,1,0,1,0,1, 0,1,1,0,0,0,0,1,1,1,0,1,1,1,1,0,0,0,0,0,1,0,1,1,0,0,1,1,1,0,0,0, 1,0,0,1,1,1,1,0,1,1,1,1,0,1,0,1,0,0,1,0,1,0,0,0,1,1,0,0,0,0,1,1, 0,1,1,1,0,0,0,0,0,1,0,0,1,0,1,0,0,0,0,1,1,1,0,1,1,0,1,1,0,1,1,0, 0,1,0,0,0,0,1,1,0,0,1,0,1,1,0,0,1,0,0,1,0,1,0,1,1,1,1,1,1,0,1,0, 1,0,1,1,1,1,1,0,0,0,0,1,0,1,1,1,0,1,1,0,0,0,0,0,1,0,0,0,1,1,0,1};const unsigned char MODIFIED_SBOX_7[4*64] ={ 0,1,0,0,1,0,1,1,0,0,1,0,1,1,1,0,1,1,1,1,0,0,0,0,1,0,0,0,1,1,0,1, 0,0,1,1,1,1,0,0,1,0,0,1,0,1,1,1,0,1,0,1,1,0,1,0,0,1,1,0,0,0,0,1, 1,1,0,1,0,0,0,0,1,0,1,1,0,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1,1,0,1,0, 1,1,1,0,0,0,1,1,0,1,0,1,1,1,0,0,0,0,1,0,1,1,1,1,1,0,0,0,0,1,1,0, 0,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,1,1,0,0,0,0,1,1,0,1,1,1,1,1,1,0, 1,0,1,0,1,1,1,1,0,1,1,0,1,0,0,0,0,0,0,0,0,1,0,1,1,0,0,1,0,0,1,0, 0,1,1,0,1,0,1,1,1,1,0,1,1,0,0,0,0,0,0,1,0,1,0,0,1,0,1,0,0,1,1,1, 1,0,0,1,0,1,0,1,0,0,0,0,1,1,1,1,1,1,1,0,0,0,1,0,0,0,1,1,1,1,0,0};const unsigned char MODIFIED_SBOX_8[4*64] ={ 1,1,0,1,0,0,1,0,1,0,0,0,0,1,0,0,0,1,1,0,1,1,1,1,1,0,1,1,0,0,0,1, 1,0,1,0,1,0,0,1,0,0,1,1,1,1,1,0,0,1,0,1,0,0,0,0,1,1,0,0,0,1,1,1, 0,0,0,1,1,1,1,1,1,1,0,1,1,0,0,0,1,0,1,0,0,0,1,1,0,1,1,1,0,1,0,0, 1,1,0,0,0,1,0,1,0,1,1,0,1,0,1,1,0,0,0,0,1,1,1,0,1,0,0,1,0,0,1,0, 0,1,1,1,1,0,1,1,0,1,0,0,0,0,0,1,1,0,0,1,1,1,0,0,1,1,1,0,0,0,1,0, 0,0,0,0,0,1,1,0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,1,1,0,1,0,1,1,0,0,0, 0,0,1,0,0,0,0,1,1,1,1,0,0,1,1,1,0,1,0,0,1,0,1,0,1,0,0,0,1,1,0,1, 1,1,1,1,1,1,0,0,1,0,0,1,0,0,0,0,0,0,1,1,0,1,0,1,0,1,1,0,1,0,1,1};const unsigned char PBOX_PERMUTATION[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 void shift_half_key_left(unsigned char *k){ unsigned char x = *k; unsigned char *kmax = k + (DES_KEY_SIZE/2-1); do k[0] = k[1]; while (++k < kmax); *k = x;}/*-----------------------------------------------------------------------------This function performs the required shifts and precomputes the 16 shiftedand compressed keys.-----------------------------------------------------------------------------*/void des::initialize(const unsigned char key[DES_KEY_SIZE]){ unsigned char shifted_key[DES_KEY_SIZE]; memcpy(shifted_key, key, DES_KEY_SIZE); for (int round = 0; round < DES_ROUNDS; round++) { shift_half_key_left(shifted_key); shift_half_key_left(shifted_key+DES_KEY_SIZE/2); if (KEY_SHIFT[round] == 2) { shift_half_key_left(shifted_key); shift_half_key_left(shifted_key+DES_KEY_SIZE/2); } for (int i = 0; i < DES_SBUFFER_SIZE; i++) { compressed_shifted_key[round][i] = shifted_key[COMPRESSION_PERMUTATION[i]-1]; } }}/*-----------------------------------------------------------------------------This function performs a DES encryption or decryption on a single 64-bit blockof data, using the specified 56-bit key. The data and key are packed one bitper byte. Every element of data[] must be either 0 or 1. The resultswill be highly anomalous if this is not the case.The encrypted or decrypted data is returned to the data[] buffer.-----------------------------------------------------------------------------*/void des::encrypt_decrypt(unsigned char data[DES_DATA_SIZE], int /* boolean */ encrypt){ unsigned char sbuffer[DES_SBUFFER_SIZE]; union pbuffer_tag { unsigned char byte[DES_DATA_SIZE/2]; DWORD dword[DES_DATA_SIZE/8]; } pbuffer; for (int round = 0; round < DES_ROUNDS; round++) { /* XOR compressed key with expanded right half of data */ { int i; for (i = 0; i < DES_SBUFFER_SIZE; i++) { sbuffer[i] = data[DES_DATA_SIZE/2 + EXPANSION_PERMUTATION[i]-1] ^ compressed_shifted_key[encrypt ? round : 15-round][i]; } } /* S-Box substitutions */ {#define index(n) (sbuffer[n]<<5+2 | sbuffer[n+5]<<4+2 | \ sbuffer[n+1]<<3+2 | sbuffer[n+2]<<2+2 | sbuffer[n+3]<<1+2 | \ sbuffer[n+4]<<0+2) pbuffer.dword[0] = * (DWORD *) (MODIFIED_SBOX_1 + index(0)); pbuffer.dword[1] = * (DWORD *) (MODIFIED_SBOX_2 + index(6)); pbuffer.dword[2] = * (DWORD *) (MODIFIED_SBOX_3 + index(12)); pbuffer.dword[3] = * (DWORD *) (MODIFIED_SBOX_4 + index(18)); pbuffer.dword[4] = * (DWORD *) (MODIFIED_SBOX_5 + index(24)); pbuffer.dword[5] = * (DWORD *) (MODIFIED_SBOX_6 + index(30)); pbuffer.dword[6] = * (DWORD *) (MODIFIED_SBOX_7 + index(36)); pbuffer.dword[7] = * (DWORD *) (MODIFIED_SBOX_8 + index(42)); } /* XOR and swap */ if (round < 15) { int i; for (i = 0; i < DES_DATA_SIZE/2; i++) { unsigned char x = data[DES_DATA_SIZE/2 + i]; data[DES_DATA_SIZE/2 + i] = data[i] ^ pbuffer.byte[PBOX_PERMUTATION[i]-1]; data[i] = x; } } else { int i; for (i = 0; i < DES_DATA_SIZE/2; i++) data[i] = data[i] ^ pbuffer.byte[PBOX_PERMUTATION[i]-1]; } }}/*----------------------------------------------------------------------------This function takes 64 bits (8 bytes) of a password, XOR's it into a buffer,and DES encrypts the buffer contents with the specified key. It then returns apointer to the next character of the password.----------------------------------------------------------------------------*/const char *des::xmix(const char *password, unsigned char buffer[DES_DATA_SIZE], const unsigned char key[DES_KEY_SIZE]){ int i; for (i = 0; i < 64; i+=8) { int c = *password; if (c != 0) password++; buffer[i] ^= c >> 7 & 1; buffer[i+1] ^= c >> 6 & 1; buffer[i+2] ^= c >> 5 & 1; buffer[i+3] ^= c >> 4 & 1; buffer[i+4] ^= c >> 3 & 1; buffer[i+5] ^= c >> 2 & 1; buffer[i+6] ^= c >> 1 & 1; buffer[i+7] ^= c & 1; } initialize(key); encrypt(buffer); return password;}static unsigned char MIXER1[DES_KEY_SIZE] ={ 1,0,1,0,0,0,0,0,0,1, 0,1,0,0,1,1,0,1,0,0, 1,1,0,1,1,1,0,1,1,0, 0,0,0,0,1,0,0,1,0,1, 1,1,0,0,0,0,1,1,1,0, 0,1,0,1,1,0};static unsigned char MIXER2[DES_KEY_SIZE] ={ 1,0,1,0,1,1,0,0,0,0, 0,1,1,1,1,0,1,0,0,1, 1,1,1,0,1,0,0,0,0,0, 0,1,1,0,1,0,1,0,0,0, 1,1,0,0,0,0,1,1,0,0, 0,0,0,0,0,0};static unsigned char MIXER3[DES_KEY_SIZE] ={ 1,0,0,0,1,1,1,1,1,0, 1,0,0,0,1,1,0,0,1,0, 0,1,0,1,1,0,0,0,0,0, 0,0,1,1,1,0,0,0,1,0, 1,0,0,0,1,0,0,0,1,1, 1,1,1,1,0,0};static unsigned char MIXER4[DES_KEY_SIZE] ={ 0,1,1,0,1,0,0,0,0,1, 0,1,0,0,0,1,1,0,0,1, 0,1,0,1,1,1,0,0,0,1, 0,0,1,1,1,0,1,1,0,1, 1,1,1,1,1,0,0,0,1,0, 0,1,1,1,0,0};#ifdef TRIPLEDESstatic unsigned char MIXER5[DES_KEY_SIZE] ={ 1,1,0,1,0,0,1,1,0,1, 1,1,1,0,1,1,1,0,1,1, 0,1,1,1,0,1,0,0,1,1, 0,0,0,1,1,0,1,0,0,1, 1,1,0,1,0,1,0,1,1,0, 1,0,0,1,1,0};static unsigned char MIXER6[DES_KEY_SIZE] ={ 0,1,0,1,1,1,1,0,0,1, 1,1,1,0,1,0,0,1,1,1, 0,0,0,1,1,1,0,0,1,1, 0,0,0,1,0,0,0,0,1,1, 0,1,0,0,1,1,1,0,0,1, 0,1,1,1,1,0};static unsigned char MIXER7[DES_KEY_SIZE] ={ 1,0,1,0,0,1,1,0,1,0, 0,0,0,1,1,1,1,1,1,0, 0,0,0,0,1,0,0,0,0,0, 0,1,1,1,1,0,0,0,1,1, 1,0,0,1,1,1,0,0,0,0, 0,0,1,1,1,1};static unsigned char MIXER8[DES_KEY_SIZE] ={ 1,0,0,1,1,0,0,1,0,0, 1,1,1,0,0,1,1,1,0,1, 0,0,1,0,1,0,0,1,1,1, 0,1,0,1,0,1,1,1,1,0, 0,1,1,0,0,1,1,1,0,0, 1,1,0,0,1,1};static unsigned char MIXER9[DES_KEY_SIZE] ={ 1,1,1,0,1,0,0,1,1,1, 1,1,0,1,0,1,0,1,1,1, 0,0,0,1,1,0,1,0,0,0, 0,1,1,1,1,0,0,0,1,1, 0,1,1,1,1,0,1,1,1,1, 1,0,1,0,1,0};static unsigned char MIXER10[DES_KEY_SIZE] ={ 0,0,1,0,1,0,1,1,0,0, 1,0,1,1,0,0,1,0,1,0, 0,1,1,1,1,0,0,0,0,0, 0,1,1,1,0,1,0,0,1,1, 0,0,0,0,0,0,1,0,1,0, 1,0,0,0,0,1};static unsigned char MIXER11[DES_KEY_SIZE] ={ 0,0,1,1,0,0,1,1,1,0, 1,0,1,0,1,0,0,0,1,0, 0,1,1,1,0,1,1,1,1,0, 0,0,1,0,0,1,1,0,1,0, 0,0,1,0,0,0,0,1,0,0, 0,0,1,0,0,1};static unsigned char MIXER12[DES_KEY_SIZE] ={ 0,1,0,1,1,0,0,1,0,1, 0,1,0,0,1,1,0,1,0,0, 0,1,0,0,0,0,0,0,1,0, 1,1,0,0,1,0,1,0,1,0, 0,1,0,1,0,1,0,1,0,0, 0,1,0,0,0,0};static unsigned char MIXER13[DES_KEY_SIZE] ={ 1,0,1,0,0,0,0,1,0,1, 1,0,0,1,0,1,0,1,0,0, 1,0,1,1,1,1,0,0,1,1, 1,1,0,0,0,1,1,1,0,0, 1,0,0,1,0,1,0,0,0,0, 0,1,0,0,1,1};static unsigned char MIXER14[DES_KEY_SIZE] ={ 1,0,0,0,0,0,1,0,0,1, 1,1,0,0,1,1,0,1,0,0, 0,1,0,1,1,0,1,0,0,1, 1,1,0,0,0,0,1,0,1,0, 1,0,1,1,0,0,0,0,0,1, 1,1,1,0,0,0};static unsigned char MIXER15[DES_KEY_SIZE] ={ 0,0,1,1,1,0,0,0,1,1, 0,0,1,1,0,0,1,0,1,0, 1,0,0,0,1,0,1,0,0,1, 0,0,0,1,1,0,1,1,1,1, 0,0,0,0,0,0,1,0,0,1, 0,1,0,0,1,1};static unsigned char MIXER16[DES_KEY_SIZE] ={ 0,0,0,0,1,1,0,1,0,0, 0,0,1,0,0,1,1,1,1,1, 0,0,0,0,1,1,0,1,0,1, 0,0,0,1,1,0,0,1,0,1, 1,0,0,0,1,0,1,0,0,1, 1,0,0,0,0,0};static unsigned char MIXER17[DES_KEY_SIZE] ={ 0,0,0,0,1,1,1,0,0,1, 0,0,0,0,1,0,0,1,0,1, 0,0,1,0,0,0,1,0,1,0, 0,1,0,0,1,0,0,1,1,1, 1,1,0,0,1,0,1,0,0,0, 0,1,0,1,1,1};static unsigned char MIXER18[DES_KEY_SIZE] ={ 1,1,1,0,0,0,0,1,1,0, 1,1,0,1,0,1,1,1,0,1, 0,0,1,0,1,0,1,1,1,0, 0,1,0,0,1,0,1,0,1,1, 0,1,1,1,0,1,1,1,0,1, 0,0,1,0,0,1};#endif/*----------------------------------------------------------------------------This function hashes a password and turns it into a key. Then it initializesthe key.----------------------------------------------------------------------------*/void des::password(const char *p){ unsigned char buffer[DES_DATA_SIZE]; memset(buffer, 0, sizeof(buffer)); p = xmix(p, buffer, MIXER1); p = xmix(p, buffer, MIXER2); p = xmix(p, buffer, MIXER3); xmix(p, buffer, MIXER4); initialize(buffer);}#ifdef TRIPLEDESvoid triple_des::password(const char *pwd){ unsigned char buffer[DES_DATA_SIZE]; memset(buffer, 0, sizeof(buffer)); const char *p = pwd; p = part[0].xmix(p, buffer, MIXER1); p = part[0].xmix(p, buffer, MIXER2); p = part[0].xmix(p, buffer, MIXER3); p = part[0].xmix(p, buffer, MIXER4); p = part[0].xmix(p, buffer, MIXER5); part[0].xmix(p, buffer, MIXER6); part[0].initialize(buffer); p = pwd; p = part[1].xmix(p, buffer, MIXER7); p = part[1].xmix(p, buffer, MIXER8); p = part[1].xmix(p, buffer, MIXER9); p = part[1].xmix(p, buffer, MIXER10); p = part[1].xmix(p, buffer, MIXER11); part[1].xmix(p, buffer, MIXER12); part[1].initialize(buffer); p = pwd; p = part[2].xmix(p, buffer, MIXER13); p = part[2].xmix(p, buffer, MIXER14); p = part[2].xmix(p, buffer, MIXER15); p = part[2].xmix(p, buffer, MIXER16); p = part[2].xmix(p, buffer, MIXER17); part[2].xmix(p, buffer, MIXER18); part[2].initialize(buffer);}#endif#include <sys\stat.h>#include <stdio.h>#include <stdlib.h>#include <string.h>static FILE *input;static FILE *output;const unsigned char ENCRYPTION_SIGNATURE[16] ={ 85, 66, 67, 127, 128, 248, 92, 152, 15, 252, 175, 38, 158, 218, 22, 141};const char HELP[] = "\n" "des password input output\n" "\n" "This utility encrypts or decrypts the input file and writes the result\n" "to the output file.\n" "\n" "The password may contain any characters appropriate for a command-line\n" "argument.\n" "\n" "For example, the following command lines encrypt and decrypt a file:\n" "\n" " des password message1.txt message.cry\n" " des password message.cry message2.txt\n" "\n" "The files message1.txt and message2.txt will be identical, and the file\n" "message.cry will be thoroughly scrambled.\n" "\n" "The algorithm used is DES with a 56-bit key derived from the password.";static void error_exit(const char *format, ...){ fprintf(stderr, "\ndes: "); vfprintf(stderr, format, &format + 1); fprintf(stderr, "\n"); exit(1);}static int get_byte(void){ int c = getc(input); if (c == EOF) error_exit("Unexpected end of file"); return c;}int main(int argc, char **argv){ if (argc < 4) { puts(HELP); return 1; } #ifdef TRIPLEDES triple_des crypto; #else des crypto; #endif // get key crypto.password(argv[1]); // open input and output files input = fopen(argv[2], "rb"); if (input == NULL) error_exit("Can't open %s", argv[2]); output = fopen(argv[3], "wb"); if (output == NULL) error_exit("Can't open %s", argv[3]); // get input file length long size; { struct stat s; fstat(fileno(input), &s); size = s.st_size; } // read first 16 bytes of input file and determine whether it is an // encryption signature int /* boolean */ encrypt; { unsigned char buffer[sizeof(ENCRYPTION_SIGNATURE)]; if (fread(buffer, sizeof(buffer), 1, input) != 1 || memcmp(buffer, ENCRYPTION_SIGNATURE, sizeof(buffer)) != 0) { rewind(input); // write encryption signature to output fwrite(ENCRYPTION_SIGNATURE, sizeof(ENCRYPTION_SIGNATURE), 1, output); // write number of padding bytes to output file putc( - (int) size & 7, output); encrypt = 1 /* true */; } else { if (((int) size & 7) != 1) error_exit("Size error in input file"); size -= sizeof(ENCRYPTION_SIGNATURE) + 1 + get_byte(); encrypt = 0 /* false */; } } while (size > 0) { int count; if (size < 8) count = size; else count = 8; size -= count; static unsigned char buffer[64]; int i; if (encrypt) { i = 0; while (count-- != 0) { int c = get_byte(); buffer[i++] = c >> 7 & 1; buffer[i++] = c >> 6 & 1; buffer[i++] = c >> 5 & 1; buffer[i++] = c >> 4 & 1; buffer[i++] = c >> 3 & 1; buffer[i++] = c >> 2 & 1; buffer[i++] = c >> 1 & 1; buffer[i++] = c & 1; } while (i < 64) buffer[i++] = 0; crypto.encrypt(buffer); for (i = 0; i < 64; i += 8) { putc(buffer[i] << 7 | buffer[i+1] << 6 | buffer[i+2] << 5 | buffer[i+3] << 4 | buffer[i+4] << 3 | buffer[i+5] << 2 | buffer[i+6] << 1 | buffer[i+7], output); } } else { for (i = 0; i < 64; i+= 8) { int c = get_byte(); buffer[i] = c >> 7 & 1; buffer[i+1] = c >> 6 & 1; buffer[i+2] = c >> 5 & 1; buffer[i+3] = c >> 4 & 1; buffer[i+4] = c >> 3 & 1; buffer[i+5] = c >> 2 & 1; buffer[i+6] = c >> 1 & 1; buffer[i+7] = c & 1; } crypto.decrypt(buffer); for (i = 0; count-- != 0; i += 8) { putc(buffer[i] << 7 | buffer[i+1] << 6 | buffer[i+2] << 5 | buffer[i+3] << 4 | buffer[i+4] << 3 | buffer[i+5] << 2 | buffer[i+6] << 1 | buffer[i+7], output); } } } fclose(input); fclose(output); return 0;}/*If Triple DES is desired (in addition to regular DES), the label TRIPLEDES must be defined, usually by a -D option on the compiler command line.For the fastest operation, data used by the package is packed one bit per byte. Each byte must be either 0 or 1. The results will be highly anomalous if this is not the case.To DES encrypt or decrypt, first declare an object of the des encryption class: des crypto;To Triple DES encrypt or decrypt, first declare an object of the triple_des encryption class: triple_des crypto;If you have a 56-bit key, you can initialize a des object to encrypt and decrypt with the specified key by calling a member function: crypto.initialize(key); const unsigned char key[DES_KEY_SIZE]; 56-bit encryption and decryption key, packed one bit per byte (each byte must be either 0 or 1)If you have a 168-bit key, you can initialize a triple_des object to encrypt and decrypt with the specified key by calling a member function: crypto.initialize(key); const unsigned char key[3*DES_KEY_SIZE]; 168-bit encryption and decryption key, packed one bit per byte (each byte must be either 0 or 1)Alternatively, you may generate a key and initialize the object with a password: crypto.password(p); const char *p; pointer to nul-terminated passwordThe password may be any length (except zero), but only the first 32 characters will be used for regular DES, and only the first 48 characters will be used for Triple DES. It may contain any characters except nuls. It is case-sensitive; i.e., passwords that differ only in capitalization will produce different keys.Then to encrypt or decrypt a block of 64 bits, call the member functions: crypto.encrypt(data); crypto.decrypt(data); unsigned char data[DES_DATA_SIZE]; 64-bit block of data to be encrypted or decrypted, packed one bit per byte (each byte must be either 0 or 1)The encrypted or decrypted data is written back into the same buffer in the same format (one bit per byte).When DES.CPP is compiled as a standalone application, it produces a command-line application that encrypts or decrypts a file using a password taken from the first command-line argument. If TRIPLEDES is defined, it uses Triple DES encryption and runs noticeably slower; otherwise it uses regular DES. The two methods are not compatible. A file encrypted with regular DES cannot be decrypted with Triple DES, or vice-versa, even if the passwords are identical. */