C语言实现任何文件的加密解密

来源：互联网发布：大势至usb端口编辑：程序博客网时间：2024/04/19 18:04
使用命令提示符，实现任何文件的加密和解密功能。
代码如下：
//#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <string.h>#include <stdlib.h>#include<time.h>#include<sys/stat.h>#pragma warning(disable:4996)//加密void Encryption(char *p, size_t n){for (int i = 0; i < n;++i){*p += 7;}}//解密void Decrypt(char *p, size_t n){for (int i = 0; i < n;++i){*p -= 7;}}char *EnOrDe = {0};int main(int argc, char *args[]){clock_t c1 = clock();//系统当前时间，毫秒为单位char *FileNameSrc = (char *)calloc(160, sizeof(char));//待操作文件char *p2 = (char *)calloc(200, sizeof(char));//操作后文件名//从命令行获取文件名和要处理的操作FileNameSrc = args[1];//文件名，包含路径char *p1 = args[1];EnOrDe = args[2];//en表示加密，de表示解密/*FileNameSrc =  "E:\\iPhone6-new.txt" ;char *p1 = FileNameSrc;EnOrDe = "de";*//**********处理生成新的文件名***********///char *p2 = { 0 };/*FileNameSrc = p1;*///printf("%s\n", FileNameSrc);//printf("%s\n", EnOrDe);int index = 0;while (*p1){if (*p1!='.'){*p2 = *p1;p2++;p1++;index++;}else if (*p1 == '.'){*p2 = '_';p2++;*p2 = 'H';p2++;*p2 = '.';p2++;p1++;index+=2;}}printf("\n");printf("信息摘要：\n");printf("--------------------------------------\n");printf("原文件:%s\n", FileNameSrc);printf("操作:%s  （en——加密，de——解密）\n", EnOrDe);printf("预计结果文件:%s\n", p2 - index - 1);printf("--------------------------------------\n\n");printf("请稍后，玩命处理中......\n");char *FileNameDst = p2 - index - 1;FILE *pr = fopen(FileNameSrc, "rb");FILE *pw = fopen(FileNameDst, "wb");struct stat st = { 0 };size_t fileSize = st.st_size;//以字节为单位//char *buf = NULL;//if (fileSize<1024*1024)//小于1M//{//buf = malloc(sizeof(char) * 1024 * 20);//分配20K//}//else//{    //  buf = malloc(sizeof(char)*fileSize / 10);//}char *buf = calloc(1024 * 1024 * 25, sizeof(int));//分配100M/*************定义函数指针***************/void(*pFunc)(char *, size_t);pFunc = NULL;if (strcmp(EnOrDe, "en") == 0){pFunc = Encryption;}else if (strcmp(EnOrDe, "de") == 0){pFunc = Decrypt;}/*************定义函数指针***************/while (!feof(pr)){//memset(buf, 0, sizeof(buf));//calloc自动初始化为0size_t  res = fread(buf, sizeof(char), sizeof(buf), pr);pFunc(buf, res);fwrite(buf, sizeof(char), res, pw);}fclose(pr);fclose(pw);printf("\n");printf("--------------------------------------\n");printf("执行成功！\n所在目录:%s\n", FileNameDst);clock_t c2 = clock();//系统当前时间，毫秒为单位printf("耗时:%u毫秒\n", c2-c1);printf("--------------------------------------\n");return 0;}
效果：
0 0