openssl3.2 - 官方demo学习 - sconnect.c

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openssl3.2 - 官方demo学习 - sconnect.c

概述

TLS客户端 - 使用根证书, 非阻塞, 向服务器要东西.

笔记

开始一个新demo学习时, 要从头配置包含路径, 麻烦. 直接拷贝上一个实现工程, 换掉实现.c方便一些.
换的新demo实现, 要加入库包含和头包含, 麻烦, 做一个公用头文件, 直接include方便一些.

/*!
\file my_openSSL_lib.h
*/#ifndef __MY_OPENSSL_LIB_H__
#define __MY_OPENSSL_LIB_H__#ifdef  _WIN32
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib") // for select()#include <windows.h>
#endif /* #ifdef  _WIN32 */#pragma comment(lib, "libcrypto.lib")
#pragma comment(lib, "libssl.lib")#include <openssl/applink.c> /*! for OPENSSL_Uplink(00007FF8B7EF0FE8,08): no OPENSSL_Applink */#ifdef  _WIN32
#define MY_SLEEP(x) Sleep(x)
#else
#define MY_SLEEP(x) sleep(x)
#endif /* #ifdef  _WIN32 */#endif /* #ifndef __MY_OPENSSL_LIB_H__ */

/*!
\file sconnect.c
\brief TLS客户端 - 使用根证书, 非阻塞, 向服务器要东西.
*//** Copyright 1998-2020 The OpenSSL Project Authors. All Rights Reserved.** Licensed under the Apache License 2.0 (the "License").  You may not use* this file except in compliance with the License.  You can obtain a copy* in the file LICENSE in the source distribution or at* https://www.openssl.org/source/license.html*//*-* A minimal program to do SSL to a passed host and port.* It is actually using non-blocking IO but in a very simple manner* sconnect host:port - it does a 'GET / HTTP/1.0'** cc -I../../include sconnect.c -L../.. -lssl -lcrypto*/
#include <stdio.h>
#include <stdlib.h>#ifdef __unix__
#include <unistd.h>
#endif#include <string.h>
#include <errno.h>
#include <openssl/err.h>
#include <openssl/ssl.h>#include "my_openSSL_lib.h"#define HOSTPORT "localhost:4433"
#define CAFILE "root.pem"int main(int argc, char *argv[])
{const char *hostport = HOSTPORT;const char *CAfile = CAFILE;const char *hostname;// char *cp;BIO *bio_out = NULL;char buf[1024 * 10], *p;SSL_CTX *ssl_ctx = NULL;SSL *ssl;BIO *bio_ssl;int i, len, off, ret = EXIT_FAILURE;if (argc > 1)hostport = argv[1];if (argc > 2)CAfile = argv[2];#ifdef WATT32dbug_init();sock_init();
#endifssl_ctx = SSL_CTX_new(TLS_client_method());/* Enable trust chain verification */SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);SSL_CTX_load_verify_locations(ssl_ctx, CAfile, NULL);/* Lets make a SSL structure */ssl = SSL_new(ssl_ctx);SSL_set_connect_state(ssl);/* Use it inside an SSL BIO */bio_ssl = BIO_new(BIO_f_ssl());BIO_set_ssl(bio_ssl, ssl, BIO_CLOSE);/* Lets use a connect BIO under the SSL BIO */bio_out = BIO_new(BIO_s_connect());BIO_set_conn_hostname(bio_out, hostport);/* The BIO has parsed the host:port and even IPv6 literals in [] */hostname = BIO_get_conn_hostname(bio_out);if (!hostname || SSL_set1_host(ssl, hostname) <= 0)goto err;/*! https://www.openssl.org/docs/man1.1.1/man3/BIO_set_nbio.html* sets the non blocking I/O flag to n. If n is zero then blocking I/O is set. If n is 1 then non blocking I/O is set.*/BIO_set_nbio(bio_out, 1);bio_out = BIO_push(bio_ssl, bio_out); /*! append bio_out to bio_ssl, 返回的是链表头 *//*!此时的链表头还是bio_ssl, 返回的也是链表头此时 bio_out == bio_ssl, 指针地址是一样的.此时操作bio_out的效果, 先经过bio_sll, 再经过原始的bio_out, 达到一个数据流经过不同工序被分别处理的效果.*/p = "GET / HTTP/1.0\r\n\r\n";len = (int)strlen(p);off = 0;for (;;) {i = BIO_write(bio_out, &(p[off]), len);if (i <= 0) {/*! BIO_should_retry() 的充实次数为2, 如果第3次还是失败, 就返回false */if (BIO_should_retry(bio_out)) {fprintf(stderr, "write DELAY\n");MY_SLEEP(1);continue;} else {goto err;}}off += i;len -= i;if (len <= 0)break;}for (;;) {i = BIO_read(bio_out, buf, sizeof(buf));if (i == 0)break;if (i < 0) {if (BIO_should_retry(bio_out)) {fprintf(stderr, "read DELAY\n");MY_SLEEP(1);continue;}goto err;}fwrite(buf, 1, i, stdout);}ret = EXIT_SUCCESS;goto done;err:if (ERR_peek_error() == 0) { /* system call error */fprintf(stderr, "errno=%d ", errno);perror("error");} else {ERR_print_errors_fp(stderr);}done:BIO_free_all(bio_out); /*! 如果是一个链表头的bio, 用BIO_free_all()来释放 */SSL_CTX_free(ssl_ctx);return ret;
}

END

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