异或加密
解密方式是进行第二次加密后自动解密
#define BUF_SIZE (16384) //16k
/**************************************************************
功能描述: 加密实现
输入参数:
---------------------------------------------------------------
修改作者:
修改日期:
修改说明:新增
***************************************************************/
void log_encrypt(char *data, int dataLen, const char *key)
{int n = 0;//对data的每一个字符和key进行按位异或for(n = 0; n < dataLen; n++){*data = *data ^ 0x09;data++;}
}/**************************************************************
功能描述: log文件加密
输入参数:
---------------------------------------------------------------
修改作者:
修改日期:
修改说明:新增
***************************************************************/
unsigned int log_encryptFile(char *srcFileName)
{char *key = "google";int srcFd = -1;int dstFd = -1;char *tmpBuf = NULL;int tmpLen = 0;int writLen = 0;log_printf("start: CountFile build date: %s, [%s, %d]\n", __DATE__, __FUNCTION__, __LINE__);if (!srcFileName){log_printf("srcFileName err![%s, %d]\n", __FUNCTION__, __LINE__);return EXIT_FAILURE;}srcFd = open(srcFileName, O_RDWR);log_printf("srcFileName:[%s] fd:[%d]\n", srcFileName, srcFd);if (srcFd < 0){log_printf("open src file failed! [err:%d:%s]\n", errno, strerror(errno));return EXIT_FAILURE;}log_printf("file size:[%d]\n", lseek(srcFd, 0, SEEK_END));lseek(srcFd, 0, SEEK_SET);tmpBuf = (char *)malloc(BUF_SIZE);if (!tmpBuf){log_printf("malloc buf failed! [err:%d:%s]\n", errno, strerror(errno));close(srcFd);return EXIT_FAILURE;}while((tmpLen = read(srcFd, tmpBuf, BUF_SIZE)) > 0){//加密数据log_encrypt(tmpBuf, tmpLen, key);//指针会到此包开始处lseek(srcFd, -tmpLen, SEEK_CUR);//写文件writLen = write(srcFd, tmpBuf, tmpLen);if (writLen < 0){log_printf("write err,Error: %s\n", strerror(errno));}}close(srcFd);free(tmpBuf);log_printf("end: ok: [%s, %d]\n", __FUNCTION__, __LINE__);return EXIT_SUCCESS;
}
AES加密
AES的算法时间复杂度最低,256K时间如下:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/sha.h>#define BLOCK_SIZE 16
#define KEY_BIT 256
#define IV_SIZE BLOCK_SIZE
#define KEY_SIZE (KEY_BIT/8)
#define JIEMI_SWITCH 1 //解密开关
// Generate IV
unsigned char iv[IV_SIZE] = {0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f};void file_encrypt(char* filename) {FILE* fp = fopen(filename, "rb");FILE* outfp = fopen("encrypted.tmp", "wb");if(fp == NULL) {printf("Can't open file.\n");return;}// Generate keyunsigned char key[KEY_SIZE];SHA256((unsigned char*)"google", strlen("google"), key);EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();if(EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv) != 1) {printf("Failed to initialize encryption.\n");return;}unsigned char data_block[BLOCK_SIZE];unsigned char encrypt_block[BLOCK_SIZE + EVP_MAX_BLOCK_LENGTH];int out_len;fseek(fp, 0, SEEK_END);long file_size = ftell(fp);fseek(fp, 0, SEEK_SET);unsigned char* buffer = (unsigned char*)malloc(file_size + EVP_MAX_BLOCK_LENGTH);fread(buffer, 1, file_size, fp);for(long i = 0; i < file_size; i += BLOCK_SIZE) {memcpy(data_block, buffer + i, BLOCK_SIZE);if(i + BLOCK_SIZE > file_size) {for(int j = file_size % BLOCK_SIZE; j < BLOCK_SIZE; ++j)data_block[j] = BLOCK_SIZE - (file_size % BLOCK_SIZE);}if(EVP_EncryptUpdate(ctx, encrypt_block, &out_len, data_block, BLOCK_SIZE) != 1) {printf("Failed to encrypt block.\n");return;}fwrite(encrypt_block, 1, out_len, outfp);}if(EVP_EncryptFinal_ex(ctx, encrypt_block, &out_len) != 1) {printf("Failed to finish encryption.\n");return;}fwrite(encrypt_block, 1, out_len, outfp);free(buffer);fclose(fp);fclose(outfp);rename("encrypted.tmp", filename);EVP_CIPHER_CTX_free(ctx);
}void file_decrypt(char* filename) {FILE* fp = fopen(filename, "rb");FILE* outfp = fopen("decrypted.tmp", "wb");if(fp == NULL) {printf("Can't open file.\n");return;}// Generate keyunsigned char key[KEY_SIZE];SHA256((unsigned char*)"google", strlen("google"), key);EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();if(EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv) != 1) {printf("Failed to initialize decryption.\n");return;}unsigned char data_block[BLOCK_SIZE];unsigned char decrypt_block[BLOCK_SIZE + EVP_MAX_BLOCK_LENGTH];int out_len;fseek(fp, 0, SEEK_END);long file_size = ftell(fp);fseek(fp, 0, SEEK_SET);unsigned char* buffer = (unsigned char*)malloc(file_size + EVP_MAX_BLOCK_LENGTH);fread(buffer, 1, file_size, fp);for(long i = 0; i < file_size; i += BLOCK_SIZE) {memcpy(data_block, buffer + i, BLOCK_SIZE);if(EVP_DecryptUpdate(ctx, decrypt_block, &out_len, data_block, BLOCK_SIZE) != 1) {printf("Failed to decrypt block.\n");return;}fwrite(decrypt_block, 1, out_len, outfp);}if(EVP_DecryptFinal_ex(ctx, decrypt_block, &out_len) != 1) {printf("Failed to finish decryption.\n");return;}fwrite(decrypt_block, 1, out_len, outfp);free(buffer);fclose(fp);fclose(outfp);rename("decrypted.tmp", filename);EVP_CIPHER_CTX_free(ctx);
}int main(int argc, char **argv) {if(argc != 2) {printf("Usage: %s <file>\n", argv[0]);return 1;}char *srcFileName = argv[1];
#if JIEMI_SWITCHfile_encrypt(srcFileName);printf("加密成功\n");
#elsefile_decrypt(srcFileName);printf("解密成功\n");
#endifreturn 0;
}
简单加密
它只是对输入文件进行简单的异或加密操作,使用一个字符串作为密钥
时间复杂度较高,对257K的文件加密,要33s
/**************************************************************
修改作者:wangjj
修改日期:9/25/2023
修改说明:新增
***************************************************************/
unsigned int log_encryptFile(char *srcFileName)
{char *key = "hualaixiaofang";int keyLen = strlen(key);int ch;int i = 0;log_printf("encrytFile begin [%s,%d\n]", __FUNCTION__, __LINE__);if (!srcFileName || !key){log_printf("param err! error:%s [%s,%d]\n", strerror(errno), __FUNCTION__, __LINE__);return EXIT_FAILURE;} FILE *file = fopen(srcFileName, "rb+");if (file == NULL){log_printf("open file failed!!, error:%s [%s,%d]\n", strerror(errno), __FUNCTION__, __LINE__);return EXIT_FAILURE;}while ((ch = fgetc(file)) != EOF){// 对每个字符和key的对应字符进行加密操作ch = ch + key[i];// 将加密后的字符写回文件fseek(file, -1, SEEK_CUR);fputc(ch, file);// 更新key的位置i = (i + 1) % keyLen;}log_printf("encrytFile end [%s,%d\n]", __FUNCTION__, __LINE__);fclose(file);
}
编译方式
gcc -o decrypt_program_jiemi AES_encrypt.c -lcrypto
mbedtls加密
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mbedtls/aes.h"#define KEY_SIZE 32 // 256位密钥
#define BLOCK_SIZE 16 // 128位分组int log_encryptFile(const char* input_file) {// 打开输入文件FILE* input = fopen(input_file, "rb");if (input == NULL) {printf("无法打开输入文件\n");return -1;}const unsigned char key[KEY_SIZE] = "wjj";// 计算输入文件大小fseek(input, 0, SEEK_END);long input_size = ftell(input);fseek(input, 0, SEEK_SET);// 创建输出缓冲区unsigned char* output = (unsigned char*)malloc(input_size);if (output == NULL) {printf("内存分配失败\n");fclose(input);return -1;}// 初始化加密上下文mbedtls_aes_context ctx;mbedtls_aes_init(&ctx);mbedtls_aes_setkey_enc(&ctx, key, KEY_SIZE * 8);// 加密文件内容unsigned char input_block[BLOCK_SIZE];unsigned char output_block[BLOCK_SIZE];size_t offset = 0;size_t read_bytes;while ((read_bytes = fread(input_block, 1, BLOCK_SIZE, input)) > 0) {mbedtls_aes_crypt_ecb(&ctx, MBEDTLS_AES_ENCRYPT, input_block, output_block);memcpy(output + offset, output_block, read_bytes);offset += read_bytes;}// 关闭文件和释放资源fclose(input);mbedtls_aes_free(&ctx);// 打开输入文件,以写入方式覆盖原内容input = fopen(input_file, "wb");if (input == NULL) {printf("无法打开输入文件\n");free(output);return -1;}// 将加密后的内容写入输入文件fwrite(output, 1, input_size, input);// 关闭文件和释放资源fclose(input);free(output);printf("文件加密完成\n");return 0;
}int log_decryptFile(const char* input_file) {// 打开输入文件FILE* input = fopen(input_file, "rb");if (input == NULL) {printf("无法打开输入文件\n");return -1;}const unsigned char key[KEY_SIZE] = "wjj";// 计算输入文件大小fseek(input, 0, SEEK_END);long input_size = ftell(input);fseek(input, 0, SEEK_SET);// 创建输出缓冲区unsigned char* output = (unsigned char*)malloc(input_size);if (output == NULL) {printf("内存分配失败\n");fclose(input);return -1;}// 初始化解密上下文mbedtls_aes_context ctx;mbedtls_aes_init(&ctx);mbedtls_aes_setkey_dec(&ctx, key, KEY_SIZE * 8);// 解密文件内容unsigned char input_block[BLOCK_SIZE];unsigned char output_block[BLOCK_SIZE];size_t offset = 0;size_t read_bytes;while ((read_bytes = fread(input_block, 1, BLOCK_SIZE, input)) > 0) {mbedtls_aes_crypt_ecb(&ctx, MBEDTLS_AES_DECRYPT, input_block, output_block);memcpy(output + offset, output_block, read_bytes);offset += read_bytes;}// 关闭文件和释放资源fclose(input);mbedtls_aes_free(&ctx);// 打开输入文件,以写入方式覆盖原内容input = fopen(input_file, "wb");if (input == NULL) {printf("无法打开输入文件\n");free(output);return -1;}// 将解密后的内容写入输入文件fwrite(output, 1, input_size, input);// 关闭文件和释放资源fclose(input);free(output);printf("文件解密完成\n");return 0;
}
// 编译方式:gcc -o decrypt-jiami AES_encrypt.c -lmbedtls -lmbedcrypto -lmbedx509
int main(int argc, char **argv) {if(argc != 2) {printf("Usage: %s <file>\n", argv[0]);return 1;}char *srcFileName = argv[1];if (log_encryptFile(srcFileName) != 0) {printf("加密文件失败\n");return -1;}printf("文件加密完成\n");#if 0if (log_decryptFile(srcFileName) != 0) {printf("解密文件失败\n");return -1;}printf("解密成功\n");
#endif return 0;
}
编译方式
gcc -o decrypt-jiami AES_encrypt.c -lmbedtls -lmbedcrypto -lmbedx509