C语言实现文件加密解密

1、首先打开VC++6.0

3、选择C++ source file 新建一个空白文档

5、首先写个加密函数，算法就是简介里说的void EncryptFile(FILE *sfp,FILE *dfp,char pwd){char ch;if(sfp==0||dfp==0){printf("ERROR!\n");return;}while((ch=fgetc(sfp))!=EOF){if((ch>='a')&&(ch<='z')){ch=(ch-'a'+1)%26+'a';ch=ch^pwd;}if((ch>='A')&&(ch<='Z')){ch=(ch-'A'+1)%26+'A';ch=ch^pwd;}fputc(ch,dfp);}}

7、输出函数，输出文件内容void OutputFile(FILE *fp){char ch;while((ch=fgetc(fp))!=EOF)putchar(ch);}