文件简单加密与解密系统c语言,C语言之文件的加密与解密

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.youkuaiyun.com/zym326975/article/details/72822325

#include

#include

int getfilesize(char *path)

{

FILE *pf = fopen(path, "r");

if (pf == NULL)

{

return -1;

}

else

{

fseek(pf, 0, SEEK_END);

int length = ftell(pf);

return length;

}

}

/*

void copy(char *oldpath, char *newpath)

{

FILE *pfr, *pfw;

pfr = fopen(oldpath, "rb");

pfw = fopen(newpath, "wb");

if (pfr == NULL || pfw == NULL)

{

fclose(pfr);

fclose(pfw);

return;

}

else

{

int length = getfilesize(oldpath);

char *p = (char *)malloc(length*sizeof(char));

fread(p, sizeof(char), length, pfr);

fwrite(p, sizeof(char), length, pfw);

fclose(pfr);

fclose(pfw);

}

}

*/

void EncryptFile(char *oldpath, char *newpath)

{

int i = 0;

FILE *pfr, *pfw;

pfr = fopen(oldpath, "rb");

pfw = fopen(newpath, "wb");

if (pfr == NULL || pfw == NULL)

{

fclose(pfr);

fclose(pfw);

return;

}

else

{

int length = getfilesize(oldpath);

char *p = (char *)malloc(length*sizeof(char));

fread(p, sizeof(char), length, pfr);

for (i = 0; i < length; i++)

{

p[i] ^= 'A';

}

fwrite(p, sizeof(char), length, pfw);

fclose(pfr);

fclose(pfw);

}

}

void DecryptFile(char *oldpath, char *newpath)

{

int i = 0;

FILE *pfr, *pfw;

pfr = fopen(oldpath, "rb");

pfw = fopen(newpath, "wb");

if (pfr == NULL || pfw == NULL)

{

fclose(pfr);

fclose(pfw);

return;

}

else

{

int length = getfilesize(oldpath);

char *p = (char *)malloc(length*sizeof(char));

fread(p, sizeof(char), length, pfr);

for (i = 0; i < length; i++)

{

p[i] ^= 'A';

}

fwrite(p, sizeof(char), length, pfw);

fclose(pfr);

fclose(pfw);

}

}

void main()

{

char *oldpath = "tmAppAbDBB.db";

char *newpath = "aa.db";

char *newDecryptFilepath = "cc.db";

EncryptFile(oldpath, newpath);

DecryptFile(newpath, newDecryptFilepath);

}