C语言函数指针三（反向调用）

动态库代码

//简单的动态库开发----报文发送

#define _CRT_SECURE_NO_WARNINGS

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

//定义加密函数指针类型

typedef int(*PDesEncSocket)(char *, int , char **, int *);

//定义解密函数指针类型

typedef int(*PDesDecSocket)(char *, int , char **, int *);

//定义上下文结构体

typedef struct _SCK_HANDLE{

    //定义报文IP

    char ipaddress[];

    //定义报文端口

    char port[];

    //定义报文接受数组

    unsigned char * buf;

    //定义报文长度

    int buflen;

    //定义加密函数指针变量

    PDesEncSocket pe;

    //定义解密函数指针变量

    PDesDecSocket pd;

}SCK_HANDLE;

//初始化上下文

_declspec(dllexport)

int cltSocketInit(void **handle/*out*/){

    int ERRO_MSG = ;

    if (handle==NULL)

    {

        ERRO_MSG = ;

        printf("handle==NULL 报文初始化失败 erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    //定义上下文指针

    SCK_HANDLE *shandle = NULL;

    //分配内存

    //详述：此处分配内存必须分配堆内存（malloc函数分配），这也正是malloc函数真正的用途所在

    //此处不可以分配栈内存，栈内存会被系统自动回收，但是报文的发送与接受所使用的上下文SCK_HANDLE，必须长时间存在

    //何时回收必须由用户决定，而不能随便的被回收

    //同样使用静态区也不合适，因为无法人为回收内存空间，必须等待电脑关机，综上所述，只能使用malloc函数分配内存

    shandle = (SCK_HANDLE *)malloc(sizeof(SCK_HANDLE));

    //重置内存空间

    memset(shandle, , sizeof(SCK_HANDLE));

    strcpy(shandle->ipaddress,"192.168.0.128");

    strcpy(shandle->port, "");

    *handle = shandle;

    return ERRO_MSG;

}

//注入加密函数指针

_declspec(dllexport)

int InjectionEnc(void *handle/*in*/, PDesEncSocket pein/*in*/){

    int ERRO_MSG = ;

    if (handle == NULL||pein==NULL)

    {

        ERRO_MSG = ;

        printf("handle == NULL||pein==NULL 传入参数不可以为空  erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    SCK_HANDLE* sh = (SCK_HANDLE*)handle;

    sh->pe = pein;

    return ERRO_MSG;

}

//注入解密函数指针

_declspec(dllexport)

int InjectionDec(void *handle/*in*/, PDesDecSocket pdin/*in*/){

    int ERRO_MSG = ;

    if (handle == NULL || pdin == NULL)

    {

        ERRO_MSG = ;

        printf("handle == NULL||pdin==NULL 传入参数不可以为空  erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    SCK_HANDLE* sh = (SCK_HANDLE*)handle;

    sh->pd = pdin;

    return ERRO_MSG;

}

//客户端发报文

_declspec(dllexport)

int cltSocketSend(void *handle/*in*/, unsigned char *buf/*in*/, int buflen/*in*/){

    int ERRO_MSG = ;

    if (handle==NULL)

    {

        ERRO_MSG = ;

        printf("handle==NULL handle不可以为NULL erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    if (buf == NULL)

    {

        ERRO_MSG = ;

        printf("buf==NULL buf不可以为NULL erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    SCK_HANDLE *sh = NULL;

    sh = (SCK_HANDLE *)handle;

    if (sh->pe == NULL)

    {

        ERRO_MSG = ;

        printf("加密函数指针不可以为NULL erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    //不需要为报文开辟内存，因为加密函数会分配内存

    sh->pe(buf, buflen, &sh->buf, &sh->buflen);

    return ERRO_MSG;

}

//客户端发报文方式二

_declspec(dllexport)

int cltSocketSend2(void *handle/*in*/, unsigned char *buf/*in*/, PDesEncSocket pein/*in*/, int buflen/*in*/){

    int ERRO_MSG = ;

    if (handle == NULL)

    {

        ERRO_MSG = ;

        printf("handle==NULL handle不可以为NULL erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    if (buf == NULL)

    {

        ERRO_MSG = ;

        printf("buf==NULL buf不可以为NULL erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    if (pein == NULL)

    {

        ERRO_MSG = ;

        printf("pein==NULL 传入参数函数指针不可以为空 erro msg :%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    SCK_HANDLE *sh = NULL;

    sh = (SCK_HANDLE *)handle;

    //不需要为报文开辟内存，因为加密函数会分配内存

    //函数指针加密

    pein(buf, buflen, &sh->buf, &sh->buflen);

    return ERRO_MSG;

}

//客户端收报文

_declspec(dllexport)

int cltSocketRev(void *handle/*in*/, unsigned char **buf/*out*/, int *buflen/*in*/){

    int ERRO_MSG = ;

    if (handle == NULL || buf == NULL || buflen==NULL)

    {

        ERRO_MSG = ;

        printf("handle == NULL || buf == NULL || buflen==NULL erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    //定义临时上下文变量

    SCK_HANDLE *sh = NULL;

    sh = (SCK_HANDLE *)handle;

    //不需要分配返回报文的内存，这里有解密函数分配

    if (sh->pd==NULL)

    {

        ERRO_MSG = ;

        printf("解密函数指针为空  erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    //解密报文

    sh->pd(sh->buf, sh->buflen, buf, buflen);

    //释放上下文中字符串数组的内存空间（至于具体应用还是看场景）

    if (sh->buf!=NULL)

    {

        //释放内存

        free(sh->buf);

        //消除野指针

        sh->buf = NULL;

    }

    sh->buflen = ;

    return ERRO_MSG;

}

//客户端收报文方式二

_declspec(dllexport)

int cltSocketRev2(void *handle/*in*/, unsigned char **buf/*out*/, PDesDecSocket pdin/*in*/, int *buflen/*in*/){

    int ERRO_MSG = ;

    if (handle == NULL || buf == NULL || buflen == NULL)

    {

        ERRO_MSG = ;

        printf("handle == NULL || buf == NULL || buflen==NULL erro msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    if (pdin==NULL)

    {

        ERRO_MSG = ;

        printf("pdin == NULL  msg:%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    //定义临时上下文变量

    SCK_HANDLE *sh = NULL;

    sh = (SCK_HANDLE *)handle;

    //不需要分配返回报文的内存，这里有解密函数分配

    //解密报文

    pdin(sh->buf, sh->buflen, buf, buflen);

    //释放上下文中字符串数组的内存空间（至于具体应用还是看场景）

    if (sh->buf != NULL)

    {

        //释放内存

        free(sh->buf);

        //消除野指针

        sh->buf = NULL;

    }

    sh->buflen = ;

    return ERRO_MSG;

}

//客户端释放资源

_declspec(dllexport)

int cltSocketDestory(void **handle){

    int ERRO_MSG = ;

    if (handle==NULL)

    {

        ERRO_MSG = ;

        printf("handle==NULL%d\n", ERRO_MSG);

        return ERRO_MSG;

    }

    if (*handle!=NULL)

    {

        //释放内存

        free(*handle);

        //消除野指针

        *handle = NULL;

    }

    return ERRO_MSG;

}

业务函数代码

#ifndef _NZHANG

#define _NZHANG

//定义加密函数指针类型

typedef int(*PDesEncSocket)(char *, int, char **, int *);

//定义解密函数指针类型

typedef int(*PDesDecSocket)(char *, int, char **, int *);

//初始化上下文

int cltSocketInit(void **handle/*out*/);

//注入加密函数指针

int InjectionEnc(void *handle/*in*/, PDesEncSocket pein/*in*/);

//注入解密函数指针

int InjectionDec(void *handle/*in*/, PDesDecSocket pdin/*in*/);

//客户端发报文

int cltSocketSend(void *handle/*in*/, unsigned char *buf/*in*/, int buflen/*in*/);

//客户端发报文方式二

int cltSocketSend2(void *handle/*in*/, unsigned char *buf/*in*/, PDesEncSocket pein/*in*/, int buflen/*in*/);

//客户端收报文

int cltSocketRev(void *handle/*in*/, unsigned char **buf/*out*/, int *buflen/*in*/);

//客户端收报文方式二

int cltSocketRev2(void *handle/*in*/, unsigned char **buf/*out*/, PDesDecSocket pdin/*in*/, int *buflen/*in*/);

//客户端释放资源

int cltSocketDestory(void **handle);

#endif

//函数指针的反向调用--增加加密解密函数

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include"des.h"

#include"L001.h"

/*

利用函数指针指针实现多种加密方法加密报文

*/

//加密函数1

int DesEncSocket(char *plainstr/*in*/, int plainlen, char **cryptstr/*out*/, int *cryptlen){

    int ERRO_MSG = ;

    if (plainstr == NULL || cryptstr == NULL || cryptlen == NULL)

    {

        ERRO_MSG = ;

        printf("加密参数列表为空\n");

        return ERRO_MSG;

    }

    //des密文比明文长，但是密文最多比明文多8个字节（所以我取10个足够）

    *cryptstr = (char *)malloc((sizeof(char)*plainlen) + );

    if (cryptstr == NULL)

    {

        ERRO_MSG = ;

        printf("加密函数分配输出内存失败！\n");

        return ERRO_MSG;

    }

    int ret = DesEnc((unsigned char *)plainstr, plainlen, (unsigned char *)*cryptstr, cryptlen);

    if (ret != )

    {

        ERRO_MSG = ;

        printf("des加密函数执行失败！\n");

        return ERRO_MSG;

    }

    return ERRO_MSG;

}

//解密函数1

int DesDecSocket(char *cryptstr/*in*/, int cryptlen, char **plainstr/*out*/, int *plainlen){

    int ERRO_MSG = ;

    if (plainstr == NULL || cryptstr == NULL || plainlen == NULL)

    {

        ERRO_MSG = ;

        printf("解密参数列表为空！\n");

        return ERRO_MSG;

    }

    //分配内存空间(des密文只可能比明文长)

    *plainstr = (char *)malloc((sizeof(char)*cryptlen));

    if (plainstr == NULL)

    {

        ERRO_MSG = ;

        printf("分配输出内存失败！\n");

        return ERRO_MSG;

    }

    int ret = DesDec((unsigned char *)cryptstr, cryptlen, (unsigned char *)*plainstr, plainlen);

    if (ret != )

    {

        ERRO_MSG = ;

        printf("des解密函数执行失败！\n");

        return ERRO_MSG;

    }

    return ERRO_MSG;

}

//加密函数2

int DesEncSocket2(char *plainstr/*in*/, int plainlen, char **cryptstr/*out*/, int *cryptlen){

    int ERRO_MSG = ;

    if (plainstr == NULL || cryptstr == NULL || cryptlen == NULL)

    {

        ERRO_MSG = ;

        printf("加密参数列表为空\n");

        return ERRO_MSG;

    }

    //des密文比明文长，但是密文最多比明文多8个字节（所以我取10个足够）

    *cryptstr = (char *)malloc((sizeof(char)*plainlen) + );

    if (cryptstr == NULL)

    {

        ERRO_MSG = ;

        printf("加密函数分配输出内存失败！\n");

        return ERRO_MSG;

    }

    int ret = DesEnc((unsigned char *)plainstr, plainlen, (unsigned char *)*cryptstr, cryptlen);

    if (ret != )

    {

        ERRO_MSG = ;

        printf("des加密函数执行失败！\n");

        return ERRO_MSG;

    }

    return ERRO_MSG;

}

//解密函数2

int DesDecSocket2(char *cryptstr/*in*/, int cryptlen, char **plainstr/*out*/, int *plainlen){

    int ERRO_MSG = ;

    if (plainstr == NULL || cryptstr == NULL || plainlen == NULL)

    {

        ERRO_MSG = ;

        printf("解密参数列表为空！\n");

        return ERRO_MSG;

    }

    //分配内存空间(des密文只可能比明文长)

    *plainstr = (char *)malloc((sizeof(char)*cryptlen));

    if (plainstr == NULL)

    {

        ERRO_MSG = ;

        printf("分配输出内存失败！\n");

        return ERRO_MSG;

    }

    int ret = DesDec((unsigned char *)cryptstr, cryptlen, (unsigned char *)*plainstr, plainlen);

    if (ret != )

    {

        ERRO_MSG = ;

        printf("des解密函数执行失败！\n");

        return ERRO_MSG;

    }

    return ERRO_MSG;

}

void ProtectA(){

    //定义发送报文

    char str1[] = "";

    //定义报文长度

    int buflen1 = strlen(str1) + ;

    //定义接受报文变量

    char *buf = NULL;

    int len2 = ;

    void *handle = NULL;

    int ret = ;

    //初始化报文

    ret = cltSocketInit(&handle);

    if (ret != )

    {

        printf("初始化报文对象失败！\n");

    }

    //注入加密函数指针

    ret = InjectionEnc(handle, DesEncSocket);

    if (ret != )

    {

        printf("注入加密函数指针失败！\n");

    }

    //注入解密函数指针

    ret = InjectionDec(handle, DesDecSocket);

    if (ret != )

    {

        printf("注入解密函数指针失败！\n");

    }

    //发送报文

    ret = cltSocketSend(handle, str1, buflen1);

    if (ret != )

    {

        printf("发送报文失败！\n");

    }

    //接收报文

    ret = cltSocketRev(handle, &buf, &len2);

    if (ret != )

    {

        printf("接收报文失败！\n");

    }

    //释放报文内存

    if (buf != NULL)

    {

        //打印报文

        printf(buf);

        free(buf);

        buf = NULL;

    }

    //释放报文对象

    ret = cltSocketDestory(&handle);

    if (ret != )

    {

        printf("释放报文对象失败！\n");

    }

}

void ProtectB(){

    //定义发送报文

    char str1[] = "";

    //定义报文长度

    int buflen1 = strlen(str1) + ;

    //定义接受报文变量

    char *buf = NULL;

    int len2 = ;

    void *handle = NULL;

    int ret = ;

    //初始化报文

    ret = cltSocketInit(&handle);

    if (ret != )

    {

        printf("初始化报文对象失败！\n");

    }

    //发送报文

    ret = cltSocketSend2(handle, str1, DesEncSocket2, buflen1);

    if (ret != )

    {

        printf("发送报文失败！\n");

    }

    //接收报文

    ret = cltSocketRev2(handle, &buf, DesDecSocket2, &len2);

    if (ret != )

    {

        printf("接收报文失败！\n");

    }

    //释放报文内存

    if (buf != NULL)

    {

        //打印报文

        printf(buf);

        free(buf);

        buf = NULL;

    }

    //释放报文对象

    ret = cltSocketDestory(&handle);

    if (ret != )

    {

        printf("释放报文对象失败！\n");

    }

}

void main(){

    ProtectB();

    system("pause");

}

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C语言函数指针三（反向调用）

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巴特西

C语言 函数指针三（反向调用）

最新文章

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C语言函数指针三（反向调用）