巩固C语言(十二)----文件加解密

一 文件的简单加解密----按照字节简单加减进行加解密

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<stdlib.h>//按照字节的方式进行加解密//加密void Encryption(char *srcPath, char *destPath){FILE *src = fopen(srcPath, "r");FILE *dest = fopen(destPath, "w");if (!src || !dest){printf("文件打开失败！\n");system("pause");return;}while (!feof(src)){char ch = fgetc(src);fputc(ch + 1, dest);}fclose(src);fclose(dest);}//解密void Decrypthion(char *srcPath, char *destPath){FILE *src = fopen(srcPath, "r");FILE *dest = fopen(destPath, "w");if (!src || !dest){printf("文件打开失败！\n");system("pause");return;}while (!feof(src)){char ch = fgetc(src);fputc(ch - 1, dest);}fclose(src);fclose(dest);}void main(){char srcPath[100] = { 0 };char destPath[100] = { 0 };int flag = 0;printf("请选择类型[1：加密    0：解密]\n");scanf("%d", &flag);switch (flag){case 0:printf("请输入您要解密的文件路径及其名称;\n");scanf("%s", srcPath);printf("请输出您要输出的路径及其名称:\n");scanf("%s", destPath);Decrypthion(srcPath, destPath);break;case 1:printf("请输入您要加密的文件路径及其名称;\n");scanf("%s", srcPath);printf("请输出您要输出的路径及其名称:\n");scanf("%s", destPath);Encryption(srcPath, destPath);break;default:printf("您输入的指令有误！");break;}system("pause");}

源文件：test.txt

如果有远方那里一定种着梦想耕种它的老人随铁锹一起长成一株树站在你必经的路口如果有远方那里一定有着你的微笑你泛着星光的皓齿如北斗般引领方向如果有远方那里一定有等盼千年的你红色的落脚连衣裙以醉人的姿态等我入怀如果有远方那里一定有阳光沙滩海浪之于足迹如今之于往昔如果有远方那里一定住着一位诗人他往后背的长发还有如竹节的手指能诗善画如果有远方我想我必要去一趟拔掉电脑电源手机扔进垃圾筐反了门，锁掉窗一个轻便的行囊还有老杜用过的拄杖如果有远方我想我必要去一趟

加密之后的文件：jiami.txt

设狐匝辗妇湃琉蛹珐鬃仄南徐裹鬃听杜列商嚏望让蛹邱触词蛹纂锁挚折配操慨杜酶累设狐匝辗妇湃琉蛹珐匝仄配杜希学配富仄讶恒杜癃崔设膊犯变誉马妇畜设狐匝辗妇湃琉蛹珐匝渡葡权烹杜配豁尸杜缅酒颅用珊诱仡商杜靥铜渡嫌伸即设狐匝辗妇湃琉蛹珐匝阴恒蚀统护撂庄咱劁饯设掘庄咱晰硝设狐匝辗妇湃琉蛹珐丌仄蛹霞爽商厅晰霍泊杜触福己匝设昨聚杜俗坠泡爽是籍设狐匝辗妇嫌徐嫌操荧搔蛹吞毕鄂惰耪惰盏俗见稍均镰践礼傅绿钠き贴鄂当蛹棍肉蹭杜蜒庞己匝列菲阅湖杜柞稚设狐匝辗妇嫌徐嫌操荧搔蛹吞 

解密之后又可以回到源文件的内容！

二 按照字节异或加解密

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<stdlib.h>//按照字节的方式进行加解密//加解密void DeEncrypthion(char *srcPath, char *destPath){FILE *src = fopen(srcPath, "r");FILE *dest = fopen(destPath, "w");if (!src || !dest){printf("文件打开失败！\n");system("pause");return;}while (!feof(src)){char ch = fgetc(src);fputc(ch^123, dest);}fclose(src);fclose(dest);}void main(){char srcPath[100] = { 0 };char destPath[100] = { 0 };int flag = 0;printf("请选择类型[1：加密    0：解密]\n");scanf("%d", &flag);switch (flag){case 0:printf("请输入您要解密的文件路径及其名称;\n");scanf("%s", srcPath);printf("请输出您要输出的路径及其名称:\n");scanf("%s", destPath);DeEncrypthion(srcPath, destPath);break;case 1:printf("请输入您要加密的文件路径及其名称;\n");scanf("%s", srcPath);printf("请输出您要输出的路径及其名称:\n");scanf("%s", destPath);DeEncrypthion(srcPath, destPath);break;default:printf("您输入的指令有误！");break;}system("pause");}

结果和上一程序结果一致！

3 输入密码对字符串的加解密

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<stdlib.h>#include<string.h>//加解密函数char *EnDecrypthion(char *src, char *password){int srcLen = strlen(src);int pwLen = strlen(password);int iteger = srcLen / pwLen;for (int i = 0; i < srcLen / pwLen; i++){for (int j = 0; j < pwLen; j++){src[(iteger - 1)*i + j] ^= password[j];}}if (!(srcLen%pwLen))//能被整除的情况下{return src;}else{int remaider = srcLen%pwLen;for (int i = 0; i < remaider; i++)src[iteger*pwLen + i] ^= password[i];return src;}}void main(){char str[256] = { 0 };char password[256] = { 0 };printf("请输入一段需要加密的字符串:");scanf("%s", str);printf("请输入密码：");scanf("%s", password);printf("加密之后:%s\n", EnDecrypthion(str, password));printf("解密之后:%s\n", EnDecrypthion(str, password));system("pause");}

运行结果：

请输入一段需要加密的字符串:abcdfeg请输入密码：4567加密之后:UWUSRPQ解密之后:abcdfeg请按任意键继续. . .

4 输入密码对文件进行加解密

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<stdlib.h>#include<string.h>//加解密函数char *EnDecrypthion(char *src, char *password){int srcLen = strlen(src);int pwLen = strlen(password);int iteger = srcLen / pwLen;//循环次数for (int i = 0; i < iteger; i++){for (int j = 0; j < pwLen; j++)src[pwLen*i + j] ^= password[j];//注意此处的算法，这才是精髓所在}//处理剩下的字节if (!(srcLen%pwLen))//能被整除的情况下{return src;}else                        //不能被整除的情况下{int remaider = srcLen%pwLen;for (int i = 0; i < remaider; i++)src[iteger*pwLen + i] ^= password[i];return src;}}//获取源文件的字节长度long GetFileSize(char *Path){FILE *fp = fopen(Path, "r"); if (!fp){printf("获取文件长度时，打开文件失败！\n");return  -1;}fseek(fp, 0, SEEK_END);long sz = ftell(fp);fclose(fp);return sz;}void FileEnDecrypthion(char *srcPath, char *destPath, char *password){FILE *src = fopen(srcPath, "r");FILE *dest = fopen(destPath, "w");if (!src || !dest){printf("打开文件失败！");return;}long srcLen = GetFileSize(srcPath);//获取源文件的字节长度char *temp = (char *)malloc((srcLen + 1)*sizeof(char));for (int i = 0; i < srcLen; i++)//将文件中的字符全部拷贝到数组中{temp[i] = fgetc(src);}temp[srcLen] = '\0';//下边有问题，加密函数有问题temp = EnDecrypthion(temp, password);for (int i = 0; i < srcLen; i++)fputc(temp[i], dest);//fclose(src);fclose(dest);}void main(){char srcPath[256] = { 0 };char destPath[256] = { 0 };char password[256] = { 0 };int flag = 0;printf("请输入指令【0:加密    1:解密】:");scanf("%d", &flag);switch (flag){case 0:printf("请输入要加密的文件路径和文件名:\n");scanf("%s", srcPath);printf("请输入输出的文件路径和文件名:\n");scanf("%s", destPath);printf("请输入密码：");scanf("%s", password);FileEnDecrypthion(srcPath, destPath, password);break;case 1:printf("请输入要解密的文件路径和文件名:\n");scanf("%s", srcPath);printf("请输入输出的文件路径和文件名:\n");scanf("%s", destPath);printf("请输入密码：");scanf("%s", password);FileEnDecrypthion(srcPath, destPath, password);break;default:printf("您输入的指令有误!\n");}system("pause");}

运行结果：

请输入指令【0:加密    1:解密】:0请输入要加密的文件路径和文件名:test.txt请输入输出的文件路径和文件名:dest.txt请输入密码：123abc请按任意键继续. . .

dest.txt中的内容：

姎背鍎勡h蜍迟諜溴锭?k跇玟鴿拽颀hㄗ眾裘移续鄨穲┢8孢豆跹偣芪匂裰莨;貦搬鎱诌i貂髱柏嚉啾郸跹啣釘9詪弼饱谟圇懰徐8麊右噮儌盀疝勡瓚;貦搬鎱诌i貂髱柏嚉啾撰酎羝匂鱾h佥麡驭≌忲犖斌鷬k胺孢拽纟蚳柱貍8麊蹣忖缱辙;鲷眾剾膊才嬔ㄑ瘍8壜ⅷ鐪嗷祤崙9﹨蘩錆哺k獎埳啾墩啅9ゥ＾鄨资磹弼迟瓓鴺┅i貝€亞パ菃?谯搬窊揠圇祲8鹘ㄈ執h嬋膊穱厧k踊銟柏9熏峙囋ザ种鎳kǖ娙邲駷垯輷;厙牘狋憻獨峙唭k柏壞魛觻匂惚Ρ;墛膊￣匂病谔圇窎儿8麊蹣忖缱辙;畨冸橙珨鄨i瓮虨潨瓮虨潨瓮虨潨瓮虨潨瓮虨潨瓮

请输入指令【0:加密    1:解密】:1请输入要解密的文件路径和文件名:dest.txt请输入输出的文件路径和文件名:src.txt请输入密码：123abc请按任意键继续. . .

src.txt中的内容

如果有远方那里一定种着梦想耕种它的老人随铁锹一起长成一株树站在你必经的路口如果有远方那里一定有着你的微笑你泛着星光的皓齿如北斗般引领方向如果有远方那里一定有等盼千年的你红色的落脚连衣裙以醉人的姿态等我入怀如果有远方那里一定有阳光沙滩海浪之于足迹如今之于往昔如果有远方那里一定住着一位诗人他往后背的长发还有如竹节的手指能诗善画如果有远方我想我必要去一趟拔掉电脑电源手机扔进垃圾筐反了门，锁掉窗一个轻便的行囊还有老杜用过的拄杖如果有远方我想我必要去一趟

5 二进制文件加解密

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<stdlib.h>#include<string.h>//加解密函数char *StrEnDecrypthion(char *src, char *password){int srcLen = strlen(src);int pwLen = strlen(password);int iteger = srcLen / pwLen;//循环次数for (int i = 0; i < iteger; i++){for (int j = 0; j < pwLen; j++)src[pwLen*i + j] ^= password[j];//注意此处的算法，这才是精髓所在}//处理剩下的字节if (!(srcLen%pwLen))//能被整除的情况下{return src;}else                        //不能被整除的情况下{int remaider = srcLen%pwLen;for (int i = 0; i < remaider; i++)src[iteger*pwLen + i] ^= password[i];return src;}}long GetBinSize(char *path){FILE *fp = fopen(path, "r");if (!fp){printf("读取字节时失败！\n");fclose(fp);return -1;}fseek(fp, 0, SEEK_END);long sz = ftell(fp);return sz;}void EnDecrypthion(char *srcPath, char *destPath, char *password){FILE *src = fopen(srcPath, "rb");FILE *dest = fopen(destPath, "wb");if (!src || !dest){printf("加解密时失败！\b");fclose(src);fclose(dest);return;;}long srcLen = GetBinSize(srcPath);char *temp = (char *)malloc(srcLen*sizeof(char));//最精确和一致的村塾数字的方法就是使用与程序所使用的相同的位格式.//对于标准I/O，fread()和fwrite()函数提供了这种二进制服务。/*size_t fread( void *buffer, size_t size, size_t count, FILE *stream );fread returns the number of full items actually read, which may be less than count if an error occurs or if the end of the file is encountered before reaching count.Use the feof or ferror function to distinguish a read error from an end-of-file condition. If size or count is 0, fread returns 0 and the buffer contents are unchanged.buffer:     Storage location for datasize:       Item size in bytescount:Maximum number of items to be readstream:Pointer to FILE structureThe fread function reads up to count items of size bytes from the input stream and stores them in buffer. The file pointer associated with stream (if there is one) is increased by the number of bytes actually read.If the given stream is opened in text mode, carriage return–linefeed pairs are replaced with single linefeed characters. The replacement has no effect on the file pointer or the return value. The file-pointer position is indeterminate if an error occurs. The value of a partially read item cannot be determined.*/fread(temp, sizeof(char), srcLen, src);//读取二进制文件到内存//加解密阶段StrEnDecrypthion(temp, password);/*size_t fwrite( const void *buffer, size_t size, size_t count, FILE *stream );fwrite returns the number of full items actually written, which may be less than count if an error occurs. Also, if an error occurs, the file-position indicator cannot be determined.buffer:Pointer to data to be writtensize:Item size in bytescount:Maximum number of items to be writtenstream:Pointer to FILE structureThe fwrite function writes up to count items, of size length each, from buffer to the output stream. The file pointer associated with stream (if there is one) is incremented by the number of bytes actually written.If stream is opened in text mode, each carriage return is replaced with a carriage-return – linefeed pair. The replacement has no effect on the return value.*/fwrite(temp, sizeof(char), srcLen, dest);//将内存中的数据读到文件}void main(){char srcPath[256] = { 0 };char destPath[256] = { 0 };char password[256] = { 0 };int flag = 0;printf("请输入指令【0:加密    1:解密】:");scanf("%d", &flag);switch (flag){case 0:printf("请输入要加密的文件路径和文件名:\n");scanf("%s", srcPath);printf("请输入输出的文件路径和文件名:\n");scanf("%s", destPath);printf("请输入密码：");scanf("%s", password);EnDecrypthion(srcPath, destPath, password);break;case 1:printf("请输入要解密的文件路径和文件名:\n");scanf("%s", srcPath);printf("请输入输出的文件路径和文件名:\n");scanf("%s", destPath);printf("请输入密码：");scanf("%s", password);EnDecrypthion(srcPath, destPath, password);break;default:printf("您输入的指令有误!\n");}system("pause");}

此时所有文件都可以进行加解密，因为都是以二进制文件进行读取的。