DES加解密演算法(C語言實現)
阿新 • • 發佈:2020-10-09
DES加密和解密演算法的實現(C語言)
主要是做個記錄,害怕以後程式碼丟了,先放到這裡了。
DES再不進行介紹了,可以看上一篇的 DES 的python實現
轉載請註明出處:https://www.cnblogs.com/wangyanzhong123/p/13784272.html
說明
這個版本用了很多位運算,也沒有添加註釋,所以可能閱讀起來會有一些困難。其中實現的是 DES 的 CBC 模式下的加解密,可以保證的是結果一定是正確的。
原始碼
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <time.h> const uint8_t IP[] = { 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 }; const uint8_t invIP[] = { 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 }; const uint8_t E[] = { 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 }; const uint8_t P[] = { 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 }; const uint8_t S[8][64] = {{ /* S1 */ 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 },{ /* S2 */ 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 },{ /* S3 */ 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 },{ /* S4 */ 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 },{ /* S5 */ 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 },{ /* S6 */ 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 },{ /* S7 */ 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 },{ /* S8 */ 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 }}; const uint8_t PC1[] = { 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 }; const uint8_t PC2[] = { 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 uint8_t shift_steps[] = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 }; uint64_t pc1(uint64_t key){ uint64_t result = 0; for (int i = 0; i < 56; i ++){ result = result << 1; result = result | ((key >> (64-PC1[i])) & 0x0000000000000001); } return (result & 0x00ffffffffffffff); } uint64_t pc2(uint64_t key){ uint64_t result = 0; for (int i = 0; i < 48; i ++){ result = result << 1; result = result | (uint64_t)((key >> (56-PC2[i])) & 0x0000000000000001); } return (result & 0x0000ffffffffffff); } uint64_t ip(uint64_t input){ uint64_t result = 0; for (int i = 0; i < 64; i ++){ result = result << 1; result = result | ((input >> (64-IP[i])) & 0x0000000000000001); } return result; } uint64_t inv_ip(uint64_t input){ uint64_t result = 0; for (int i = 0; i < 64; i ++){ result = result << 1; result = result | ((input >> (64-invIP[i])) & 0x0000000000000001); } return result; } uint64_t extend(uint32_t input){ uint64_t result = 0; for (int i = 0; i < 48; i ++){ result = result << 1; result = result | (uint64_t)((input >> (32-E[i])) & 0x00000001); } return (result & 0x0000ffffffffffff); } // uint32_t s(uint64_t input){ // uint32_t result = 0; // uint8_t *blocks = (uint8_t*)malloc(sizeof(uint8_t)*8); // uint8_t row, column; // for (int i = 0; i < 8; i ++){ // blocks[i] = (uint8_t)((input >> (42 - 6*i)) & 0x000000000000003f); // row = ((blocks[i] >> 4) & 0x02) | (blocks[i] & 0x01); // column = (blocks[i] >> 1) & 0x0f; // result = result << 4; // result = result | (uint32_t)(S[i][row*16+column] & 0x0f); // } // free(blocks); // return result; // } uint32_t s(uint64_t input) { uint32_t res = 0; int row = 0; int col = 0; for (int i = 0; i < 8; i++) { row = (uint8_t) ((input & (0x0000840000000000 >> 6*i)) >> (42-6*i)); row = (row >> 4) | (row & 0x01); col = (uint8_t) ((input & (0x0000780000000000 >> 6*i)) >> (43-6*i)); res <<= 4; res |= (uint32_t) (S[i][16*row+col] & 0x0f); } return res; } uint32_t p(uint32_t input){ uint32_t result = 0; for (int i = 0; i < 32; i ++){ result = result << 1; result = result | ((input >> (32-P[i])) & 0x00000001); } return result; } void to_uint64(uint8_t *buffer, size_t buffersize, uint64_t *result){ uint32_t tmp1 = 0, tmp2 = 0; for (int i = 0; i < (buffersize/8); i ++){ tmp1 = (((uint32_t)buffer[8*i] << 24) & 0xff000000) | (((uint32_t)buffer[8*i+1] << 16) & 0x00ff0000) | (((uint32_t)buffer[8*i+2] << 8) & 0x0000ff00) | (((uint32_t)buffer[8*i+3]) & 0x000000ff); tmp2 = (((uint32_t)buffer[8*i+4] << 24) & 0xff000000) | (((uint32_t)buffer[8*i+5] << 16) & 0x00ff0000) | (((uint32_t)buffer[8*i+6] << 8) & 0x0000ff00) | (((uint32_t)buffer[8*i+7]) & 0x000000ff); result[i] = (((uint64_t)tmp1 << 32) & 0xffffffff00000000) | ((uint64_t)tmp2 & 0x00000000ffffffff); } } void to_uint8(uint64_t *buffer, size_t buffersize, uint8_t *result){ for (int i = 0; i < buffersize; i ++){ for (int j = 0; j < 8; j ++){ result[8*i+j] = (uint8_t)(buffer[i] >> (56-8*j)); } } } uint64_t hex_2_uint64(char *string){ uint64_t result = 0; size_t len = 0; len = strlen(string); for (int i = 0; i < len; i ++){ if (string[15-i] >= '0' && string[15-i] <= '9') { result += (uint64_t)(string[15-i]-'0') * ((uint64_t)(1) << (4*i)); } else if (string[15-i] >= 'a' && string[15-i] <= 'f') { result += (uint64_t)(string[15-i]-'a' + 10) * ((uint64_t)(1) << (4*i)); } else if (string[15-i] >= 'A' && string[15-i] <= 'F') { result += (uint64_t)(string[15-i]-'A' + 10) * ((uint64_t)(1) << (4*i)); } } return result; } void generateSubkeys(uint64_t key, uint64_t* subkeys){ uint32_t left, right; uint64_t roundkey = 0; uint64_t key_tmp = 0; key_tmp = pc1(key); left = (uint32_t)((key_tmp >> 28) & 0x000000000fffffff); right = (uint32_t)(key_tmp & 0x000000000fffffff); for (int i = 0; i < 16; i ++){ int shift = shift_steps[i]; left = (0x0fffffff & (left << shift)) | (left >> (28-shift)); right = (0x0fffffff & (right << shift)) | (right >> (28-shift)); roundkey = ((uint64_t)left << 28) | (uint64_t)right; roundkey = pc2(roundkey); subkeys[i] = roundkey; } } uint64_t raw_des(uint64_t text, uint64_t key, uint8_t mode){ uint64_t* subkeys = (uint64_t*)malloc(sizeof(uint64_t)*16); generateSubkeys(key, subkeys); uint32_t L = 0, R = 0, SR = 0, PR = 0, tmp = 0; uint64_t ER = 0, output = 0, subkey = 0; text = ip(text); L = (text >> 32) & 0x00000000ffffffff; R = text & 0x00000000ffffffff; for (int i = 0; i < 16; i ++){ ER = extend(R); subkey = (mode == 0) ? subkeys[i] : subkeys[15-i]; ER = ER ^ subkey; SR = s(ER); PR = p(SR); tmp = R; R = L ^ PR; L = tmp; } free(subkeys); output = inv_ip(((uint64_t)(R) << 32 ) | (uint64_t)(L)); return output; } uint64_t des_ede2(uint64_t text, uint64_t key1, uint64_t key2, uint8_t mode){ uint64_t result; result = (mode == 0) ? raw_des(text, key1, 0) : raw_des(text, key1, 1); result = (mode == 0) ? raw_des(result, key2, 1) : raw_des(result, key2, 0); result = (mode == 0) ? raw_des(result, key1, 0) : raw_des(result, key1, 1); return result; } void des_cbc_enc(FILE* in, FILE* out, uint64_t key, uint64_t iv){ uint8_t *filebuffer; size_t filesize = 0, padding_size = 0; uint64_t *blocks, *output; clock_t start, end; fseek(in, 0, SEEK_END); filesize = ftell(in); rewind(in); padding_size = 8 - filesize % 8; filebuffer = (uint8_t*)malloc(sizeof(uint8_t)*(filesize + padding_size)); blocks = (uint64_t*)malloc(sizeof(uint64_t)*((filesize + padding_size)/8)); output = (uint64_t*)malloc(sizeof(uint64_t)*((filesize + padding_size)/8)); fread(filebuffer, sizeof(uint8_t), filesize, in); memset(filebuffer+filesize, (uint8_t)padding_size, padding_size); to_uint64(filebuffer, (filesize+padding_size), blocks); start = clock(); for (int i = 0; i < (filesize+padding_size)/8; i ++){ output[i] = raw_des((blocks[i] ^ iv), key, 0); iv = output[i]; } end = clock(); fwrite(output, sizeof(uint64_t), ((filesize + padding_size)/8), out); printf("time cost: %f s\n", (double)(end-start)/CLOCKS_PER_SEC); free(filebuffer); free(blocks); free(output); } void des_cbc_dec(FILE* in, FILE* out, uint64_t key, uint64_t iv){ uint64_t *filebuffer; uint64_t *outbuffer; uint8_t *out8_tbuffer; size_t filesize = 0, padding_size = 0; clock_t start, end; fseek(in, 0, SEEK_END); filesize = ftell(in); rewind(in); filebuffer = (uint64_t*)malloc(sizeof(uint64_t)*(filesize/8)); outbuffer = (uint64_t*)malloc(sizeof(uint64_t)*(filesize/8)); out8_tbuffer = (uint8_t*)malloc(sizeof(uint8_t)*filesize); fread(filebuffer, sizeof(uint64_t), filesize/8, in); start = clock(); for (int i = 0 ; i < (filesize/8); i ++){ outbuffer[i] = raw_des(filebuffer[i], key, 1) ^ iv; iv = filebuffer[i]; } end = clock(); to_uint8(outbuffer, filesize/8, out8_tbuffer); padding_size = (size_t)out8_tbuffer[filesize-1]; fwrite(out8_tbuffer, sizeof(uint8_t), filesize-padding_size, out); printf("time cost: %f s\n", (double)(end-start)/CLOCKS_PER_SEC); free(filebuffer); free(outbuffer); free(out8_tbuffer); } int main(int argc, char **argv){ char *inputfile = "-f"; char *inputstring = "-s"; char *mod = "-enc"; if (argc < 2){ printf("usage: %s 'string'\n", argv[0]); return 1; } else { if (!strcmp(argv[1], inputfile)){ FILE *in, *out; in = fopen(argv[3], "rb"); if (in == NULL) { printf("%s not exist\n",argv[3]); return -1; } else { out = fopen(argv[4], "wb+"); (!strcmp(argv[2],mod))? des_cbc_enc(in, out, hex_2_uint64(argv[5]), hex_2_uint64(argv[6])) : des_cbc_dec(in, out, hex_2_uint64(argv[5]), hex_2_uint64(argv[6])); fclose(in); fclose(out); } } else if (!strcmp(argv[1], inputstring)) { uint64_t cipher = 0; clock_t start, end; double duration; start = clock(); for (int i = 0; i < 1000; i ++) if(!strcmp(argv[2],mod)) cipher = des_ede2(hex_2_uint64(argv[3]), hex_2_uint64(argv[4]), hex_2_uint64(argv[5]), 0); else cipher = des_ede2(hex_2_uint64(argv[3]), hex_2_uint64(argv[4]), hex_2_uint64(argv[5]), 1); end = clock(); duration = (double)(end - start) / (double)(CLOCKS_PER_SEC); printf("%llx\n", cipher); printf("enc/dec for 1000 times cost: %f s\n", duration); } } system("pause"); }