linux openssl 编程 Client端

来源：互联网发布：开源即时通讯软件编辑：程序博客网时间：2024/05/18 02:24

相关配置等请参看上一篇关于server端文章：http://blog.csdn.net/pingd/article/details/47805349

1.Client端源码：

openssl_client.c

#include <stdio.h>#include <string.h>#include <errno.h>#include <sys/socket.h>#include <resolv.h>#include <stdlib.h>#include <netinet/in.h>#include <arpa/inet.h>#include <unistd.h>#include <openssl/ssl.h>#include <openssl/err.h>#define MAXBUF 1024void ShowCerts(SSL * ssl){    X509 *cert;    char *line;    cert = SSL_get_peer_certificate(ssl);    if (cert != NULL) {        printf("Digital cert info:\n");        line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);        printf("Cert: %s\n", line);        free(line);        line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);        printf("Owner: %s\n", line);        free(line);        X509_free(cert);    } else        printf("No cert info\n");}int main(int argc, char **argv){    int sockfd, len;    struct sockaddr_in dest;    char buffer[MAXBUF + 1];    SSL_CTX *ctx;    SSL *ssl;    if (argc != 3){        printf("Usage:%s [server_ip] [server_port]\n",argv[0]);        exit(-1);    }    /* SSL 库初始化，参看 ssl-server.c 代码 */    SSL_library_init();    OpenSSL_add_all_algorithms();    SSL_load_error_strings();    ctx = SSL_CTX_new(SSLv23_client_method());    if (ctx == NULL) {        ERR_print_errors_fp(stdout);        exit(-1);    }    /* 创建一个 socket 用于 tcp 通信 */    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {        perror("Socket");        exit(errno);    }    printf("socket created\n");    /* 初始化服务器端（对方）的地址和端口信息 */    bzero(&dest, sizeof(dest));    dest.sin_family = AF_INET;    dest.sin_port = htons(atoi(argv[2]));    if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0) {        perror(argv[1]);        exit(errno);    }    printf("address created\n");    /* 连接服务器 */    if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {        perror("Connect ");        exit(errno);    }    printf("server connected\n");    /* 基于 ctx 产生一个新的 SSL */    ssl = SSL_new(ctx);    SSL_set_fd(ssl, sockfd);    /* 建立 SSL 连接 */    if (SSL_connect(ssl) == -1)        ERR_print_errors_fp(stderr);    else {        printf("Connected with %s encryption\n", SSL_get_cipher(ssl));        ShowCerts(ssl);    }    /* 接收对方发过来的消息，最多接收 MAXBUF 个字节 */    bzero(buffer, MAXBUF + 1);    /* 接收服务器来的消息 */    len = SSL_read(ssl, buffer, MAXBUF);    if (len > 0)        printf("recv message '%s' ok.total size:'%d'\n",               buffer, len);    else {        printf("recv message error!error code:'%d',error info:'%s'\n",             errno, strerror(errno));        goto finish;    }    bzero(buffer, MAXBUF + 1);    strcpy(buffer, "from client->server");    /* 发消息给服务器 */    len = SSL_write(ssl, buffer, strlen(buffer));    if (len < 0)        printf("send message '%s' error!error code:'%d',error info:'%s'\n",             buffer, errno, strerror(errno));    else        printf("send message '%s' ok,total size:'%d'\n",buffer, len);  finish:    /* 关闭连接 */    SSL_shutdown(ssl);    SSL_free(ssl);    close(sockfd);    SSL_CTX_free(ctx);    return 0;}

2.编译

gcc -o openssl_client openssl_client.c -Wall -lssl -lcrypto -L./openssl-1.0.2d/ -Wl,-rpath=./openssl-1.0.2d

3.运行

Usage:openssl_client [server_ip] [server_port]

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