C语言代码实现简单的加密、解密文件

野性酷女 2022-11-01 05:24 195阅读 0赞

代码如下：

#include<stdlib.h>
    #include <stdio.h>
    #pragma warning(disable : 4996)
     
    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()
    {           
    	// 原始文件的路径
        char *oldpath = "tmAppAbDBB.db";
        // 加密后的路径
        char *newpath = "aa.db";
        // 解密后的路径
        char *newDecryptFilepath = "cc.db";
        EncryptFile(oldpath, newpath);
        DecryptFile(newpath, newDecryptFilepath);
    }