linux使用openssl对socket通信加密

//普通的tcp服务器端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc, char *argv[])
{
int server_sockfd;//服务器端套接字
int client_sockfd;//客户端套接字
int len;
struct sockaddr_in my_addr;   //服务器网络地址结构体
struct sockaddr_in remote_addr; //客户端网络地址结构体
int sin_size;
char buf[BUFSIZ];  //数据传送的缓冲区
    memset(&my_addr,0,sizeof(my_addr)); //数据初始化--清零
    my_addr.sin_family=AF_INET; //设置为IP通信
    my_addr.sin_addr.s_addr=INADDR_ANY;//服务器IP地址--允许连接到所有本地地址上
    my_addr.sin_port=htons(8000); //服务器端口号

/*创建服务器端套接字--IPv4协议，面向连接通信，TCP协议*/
if((server_sockfd=socket(PF_INET,SOCK_STREAM,0))<0)
    {  
        perror("socket");
return 1;
    }

/*将套接字绑定到服务器的网络地址上*/
if (bind(server_sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))<0)
    {
        perror("bind");
return 1;
    }

/*监听连接请求--监听队列长度为5*/
    listen(server_sockfd,5);

    sin_size=sizeof(struct sockaddr_in);

/*等待客户端连接请求到达*/
if((client_sockfd=accept(server_sockfd,(struct sockaddr *)&remote_addr,&sin_size))<0)
    {
        perror("accept");
return 1;
    }
    printf("accept client %s/n",inet_ntoa(remote_addr.sin_addr));
    len=send(client_sockfd,"Welcome to my server/n",21,0);//发送欢迎信息

/*接收客户端的数据并将其发送给客户端--recv返回接收到的字节数，send返回发送的字节数*/
while((len=recv(client_sockfd,buf,BUFSIZ,0))>0))
    {
        buf[len]='/0';
        printf("%s/n",buf);
if(send(client_sockfd,buf,len,0)<0)
        {
            perror("write");
return 1;
        }
    }
    close(client_sockfd);
    close(server_sockfd);
return 0;
}

//普通的tcp客户端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc, char *argv[])
{
int client_sockfd;
int len;
struct sockaddr_in remote_addr; //服务器端网络地址结构体
char buf[BUFSIZ];  //数据传送的缓冲区
    memset(&remote_addr,0,sizeof(remote_addr)); //数据初始化--清零
    remote_addr.sin_family=AF_INET; //设置为IP通信
    remote_addr.sin_addr.s_addr=inet_addr("127.0.0.1");//服务器IP地址
    remote_addr.sin_port=htons(8000); //服务器端口号

/*创建客户端套接字--IPv4协议，面向连接通信，TCP协议*/
if((client_sockfd=socket(PF_INET,SOCK_STREAM,0))<0)
    {
        perror("socket");
return 1;
    }

/*将套接字绑定到服务器的网络地址上*/
if(connect(client_sockfd,(struct sockaddr *)&remote_addr,sizeof(struct sockaddr))<0)
    {
        perror("connect");
return 1;
    }
    printf("connected to server/n");
    len=recv(client_sockfd,buf,BUFSIZ,0);//接收服务器端信息
         buf[len]='/0';
    printf("%s",buf); //打印服务器端信息

/*循环的发送接收信息并打印接收信息--recv返回接收到的字节数，send返回发送的字节数*/
while(1)
    {
        printf("Enter string to send:");
        scanf("%s",buf);
if(!strcmp(buf,"quit")
break;
        len=send(client_sockfd,buf,strlen(buf),0);
        len=recv(client_sockfd,buf,BUFSIZ,0);
        buf[len]='/0';
        printf("received:%s/n",buf);
    }
    close(client_sockfd);//关闭套接字
return 0;
}

/*********************openssl加密解密函数******************************/

aes_options.h

#ifndef _ASE_H_
#define _ASE_H_
int encrypt(char *input_string, char **encrypt_string);
void decrypt(char *encrypt_string, char **decrypt_string, int len);
#endif

aes_options.c

#include <stdio.h>
#include <openssl/aes.h>
#include <stdlib.h>
#include <string.h>

int encrypt(char *input_string, char **encrypt_string)
{
    AES_KEY aes;
unsigned char key[AES_BLOCK_SIZE];        // AES_BLOCK_SIZE = 16
unsigned char iv[AES_BLOCK_SIZE];        // init vector
unsigned int len;        // encrypt length (in multiple of AES_BLOCK_SIZE)
unsigned int i;

// set the encryption length
    len = 0;
if ((strlen(input_string) + 1) % AES_BLOCK_SIZE == 0) 
    {
        len = strlen(input_string) + 1;
    } 
else 
    {
        len = ((strlen(input_string) + 1) / AES_BLOCK_SIZE + 1) * AES_BLOCK_SIZE;
    }

// Generate AES 128-bit key
for (i=0; i<16; ++i) {
        key[i] = 32 + i;
    }

// Set encryption key
for (i=0; i<AES_BLOCK_SIZE; ++i) {
        iv[i] = 0;
    }
if (AES_set_encrypt_key(key, 128, &aes) < 0) {
fprintf(stderr, "Unable to set encryption key in AES\n");
exit(0);
    }

// alloc encrypt_string
    *encrypt_string = (unsigned char*)calloc(len, sizeof(unsigned char));    
if (*encrypt_string == NULL) {
fprintf(stderr, "Unable to allocate memory for encrypt_string\n");
exit(-1);
    }

// encrypt (iv will change)
    AES_cbc_encrypt(input_string, *encrypt_string, len, &aes, iv, AES_ENCRYPT);
return len;
}

void decrypt(char *encrypt_string, char **decrypt_string,int len)
{
unsigned char key[AES_BLOCK_SIZE];        // AES_BLOCK_SIZE = 16
unsigned char iv[AES_BLOCK_SIZE];        // init vector
    AES_KEY aes;
int i;
// Generate AES 128-bit key

for (i=0; i<16; ++i) {
        key[i] = 32 + i;
    }

// alloc decrypt_string
    *decrypt_string = (unsigned char*)calloc(len, sizeof(unsigned char));
if (*decrypt_string == NULL) {
fprintf(stderr, "Unable to allocate memory for decrypt_string\n");
exit(-1);
    }

// Set decryption key
for (i=0; i<AES_BLOCK_SIZE; ++i) {
        iv[i] = 0;
    }
if (AES_set_decrypt_key(key, 128, &aes) < 0) {
fprintf(stderr, "Unable to set decryption key in AES\n");
exit(-1);
    }

// decrypt
    AES_cbc_encrypt(encrypt_string, *decrypt_string, len, &aes, iv, 
            AES_DECRYPT);
}

/***********将普通的tcp服务器及客户端进行加密处理************************/
//服务器

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include "aes_options.h" //add

int main()
{
int server_fd;
int client_fd;
int len;
struct sockaddr_in server_addr;
struct sockaddr_in client_addr;
int sin_size;
char buffer[BUFSIZ];
// printf("%d",BUFSIZ);
memset(&server_addr, 0, sizeof(server_addr));  //initialize struct
memset(&server_addr, 0, sizeof(client_addr));

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(9000);

if((server_fd = socket(PF_INET, SOCK_STREAM, 0)) < 0)   //create server socket
    {
        perror("socket create failed");
return 1;
    }

if(bind(server_fd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) < 0) //bind info on server socket
    {
        perror("bind failed");
return 1;
    }

    listen(server_fd, 5);   //listen port 9000 

    sin_size = sizeof(struct sockaddr_in);

if((client_fd = accept(server_fd, (struct sockaddr *)&client_addr, &sin_size)) < 0)
    {
        perror("accept failed");
return 1;   
    }

printf("accept client %s\n", inet_ntoa(client_addr.sin_addr));
    len = send(client_fd, "Welcome to my server\n", 21, 0);

while((len=recv(client_fd, buffer, BUFSIZ, 0)) > 0)
    {

char *decryto_string = NULL;                          //add
//进行解密处理
        decrypt(buffer, &decryto_string, len);                //add
printf("%s \n", decryto_string);
if(send(client_fd, decryto_string, len, 0) < 0)       //modified
        {
            perror("send failed");
return 1;
        }
    }

    close(client_fd);
    close(server_fd);

return 0;
}

//客户端

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include "aes_options.h" //add

int main()
{
int len;
int client_sockfd;  
struct sockaddr_in server_addr;
char buffer[BUFSIZ];
char *encrypt_string = NULL;
memset(&server_addr, 0, sizeof(server_addr));

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(9000);

if((client_sockfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
    {
        perror("socket create failed");
return 1;

    }


if(connect(client_sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) < 0)
    {
        perror("connect failed");
return 1;
    }

printf("connect to server\n");
    len = recv(client_sockfd, buffer, BUFSIZ, 0);

    buffer[len] = '\0';
printf("%s", buffer);

while(1)
    {
printf("enter a data:");
scanf("%s", buffer);
if(!strcmp(buffer,"quit"))
break;
//进行加密处理
int encrypt_length = encrypt(buffer, &encrypt_string);     //add
        len = send(client_sockfd, encrypt_string, encrypt_length, 0); //add
        len = recv(client_sockfd, buffer, BUFSIZ, 0);
        buffer[len] = '\0';
printf("recived:%s \n", buffer);
    }

    close(client_sockfd);
printf("bye");


return 0;
}

//编译时

gcc aes_options.c socket_comunication_server.c -o server -lcrypto
gcc aes_options.c socket_comunication_client.c -o client -lcrypto## 标题文字 ##