几天来我一直试图解决我的问题,但就是无法解决问题。我尝试使用 Boost::Asio 库和 OpenSSL 建立 SSL 连接。有一个示例代码,如何执行此操作:http://www.boost.org/doc/libs/1_55_0/doc/html/boost_asio/example/cpp03/ssl/client.cpp
它构建和运行良好,甚至验证似乎也有效,但是当我发送一个简单的请求时,很长一段时间没有任何反应,然后我收到一条错误消息:“读取失败:短读取”。我想,我只是把请求行本身做错了,但我不知道它是怎么回事。我尝试了以下两行:
GET / HTTP/1.1<CR><LF>Host: www.google.de<CR><LF>Connection: close<CR><LF><CR><LF>
GET / HTTP/1.1\r\nHost: www.google.de\r\nConnection: close\r\n\r\n
我无法发布图片,因为这是我的第一篇文章,但您可以在此处找到命令窗口:
提前致谢!
更新:我让它工作了! :D 非常感谢 sehe,我只需要更改代码中的第 77 行:
size_t request_length = strlen(request_);
到:
size_t request_length = strlen(raw);
现在它工作得很好,谢谢你的帮助:)
我还是不明白,为什么 boost 示例代码不能按我预期的那样工作..
最佳答案
哈!
我抽空又看了一遍。我这里的代码 ( http://coliru.stacked-crooked.com/a/2042c3d24a16c6ac ) 已经几乎正确了。除了一个非常简单的错误:
size_t request_length = strlen(request_);
看起来无伤大雅,不是吗?除了... request_
此时未初始化。它需要(在上下文中):
static char const raw[] = "GET / HTTP/1.1\r\nHost: www.google.de\r\nConnection: close\r\n\r\n";
static_assert(sizeof(raw)<=sizeof(request_), "too large");
size_t request_length = strlen(raw);
std::copy(raw, raw+request_length, request_);
当然,您链接到的官方 Boost 示例中不存在此问题(因为它使用 std::cin.getline
直接读入请求缓冲区)。但是,您可能和我一样犯了同样的初学者错误。
希望这对您有所帮助。
附件是一个完整的工作演示,您甚至可以切换到使用 HTTPS 或不使用预处理器指令:
#define SEHE_USE_SSL
另请注意,我用过
ctx.set_default_verify_paths();
因此您可以使用在您的机器上注册的默认根授权证书(如果您的 openssl 安装有它)。
完整代码
#define SEHE_USE_SSL
#define BOOST_ASIO_ENABLE_HANDLER_TRACKING
#include <cstdlib>
#include <iostream>
#include <iomanip>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
class client
{
public:
client(boost::asio::io_service& io_service,
boost::asio::ssl::context& context,
boost::asio::ip::tcp::resolver::iterator endpoint_iterator)
: socket_(io_service
#ifdef SEHE_USE_SSL
, context)
{
socket_.set_verify_mode(boost::asio::ssl::verify_peer);
socket_.set_verify_callback(
boost::bind(&client::verify_certificate, this, _1, _2));
#else
)
{
(void) context;
#endif
boost::asio::async_connect(socket_.lowest_layer(), endpoint_iterator,
boost::bind(&client::handle_connect, this,
boost::asio::placeholders::error));
}
bool verify_certificate(bool preverified,
boost::asio::ssl::verify_context& ctx)
{
// The verify callback can be used to check whether the certificate that is
// being presented is valid for the peer. For example, RFC 2818 describes
// the steps involved in doing this for HTTPS. Consult the OpenSSL
// documentation for more details. Note that the callback is called once
// for each certificate in the certificate chain, starting from the root
// certificate authority.
// In this example we will simply print the certificate's subject name.
char subject_name[256];
X509* cert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
X509_NAME_oneline(X509_get_subject_name(cert), subject_name, 256);
std::cout << "Verifying " << subject_name << "\n";
return true || preverified;
}
void handle_connect(const boost::system::error_code& error)
{
#ifdef SEHE_USE_SSL
if (!error)
{
socket_.async_handshake(boost::asio::ssl::stream_base::client,
boost::bind(&client::handle_handshake, this,
boost::asio::placeholders::error));
}
else
{
std::cout << "Connect failed: " << error.message() << "\n";
}
#else
handle_handshake(error);
#endif
}
void handle_handshake(const boost::system::error_code& error)
{
if (!error)
{
std::cout << "Enter message: ";
static char const raw[] = "GET / HTTP/1.1\r\nHost: www.google.de\r\nConnection: close\r\n\r\n";
static_assert(sizeof(raw)<=sizeof(request_), "too large");
size_t request_length = strlen(raw);
std::copy(raw, raw+request_length, request_);
{
// used this for debugging:
std::ostream hexos(std::cout.rdbuf());
for(auto it = raw; it != raw+request_length; ++it)
hexos << std::hex << std::setw(2) << std::setfill('0') << std::showbase << ((short unsigned) *it) << " ";
std::cout << "\n";
}
boost::asio::async_write(socket_,
boost::asio::buffer(request_, request_length),
boost::bind(&client::handle_write, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
std::cout << "Handshake failed: " << error.message() << "\n";
}
}
void handle_write(const boost::system::error_code& error,
size_t /*bytes_transferred*/)
{
if (!error)
{
std::cout << "starting read loop\n";
boost::asio::async_read_until(socket_,
//boost::asio::buffer(reply_, sizeof(reply_)),
reply_, '\n',
boost::bind(&client::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
std::cout << "Write failed: " << error.message() << "\n";
}
}
void handle_read(const boost::system::error_code& error, size_t /*bytes_transferred*/)
{
if (!error)
{
std::cout << "Reply: " << &reply_ << "\n";
}
else
{
std::cout << "Read failed: " << error.message() << "\n";
}
}
private:
#ifdef SEHE_USE_SSL
boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket_;
#else
boost::asio::ip::tcp::socket socket_;
#endif
char request_[1024];
//char reply_ [1024];
boost::asio::streambuf reply_;
};
int main(int argc, char* argv[])
{
try
{
if (argc != 3)
{
std::cerr << "Usage: client <host> <port>\n";
return 1;
}
boost::asio::io_service io_service;
boost::asio::ip::tcp::resolver resolver(io_service);
boost::asio::ip::tcp::resolver::query query(argv[1], argv[2]);
boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
boost::asio::ssl::context ctx(boost::asio::ssl::context::sslv23);
ctx.set_default_verify_paths();
client c(io_service, ctx, iterator);
io_service.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
关于c++ - Boost::Asio,SSL 连接问题,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21683142/