c++ - 简单的 boost ASIO https 不返回正文

Question

我正在尝试使用 boost 示例 HTTPS 客户端，但是，使用路径/向 google.com 发送一个简单的获取请求没有返回正文。

输出:

Verifying /OU=GlobalSign Root CA - R2/O=GlobalSign/CN=GlobalSign
Verifying /C=US/O=Google Trust Services/CN=Google Internet Authority G3
Verifying /C=US/ST=California/L=Mountain View/O=Google LLC/CN=www.google.com
Handshake OK
Request:
GET / HTTP/1.1
Host: www.google.com
Accept: */*
Connection: close


Reply: HTTP/1.1 200 OK
Date: Thu, 12 Jul 2018 04:23:20 GMT
Expires: -1
Cache

奇怪的是，它在缓存处中断了。这是代码:

#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include <boost/asio/ssl.hpp>

using boost::asio::ip::tcp;

#include <wincrypt.h>
#pragma comment(lib, "crypt32.lib")

enum { max_length = 10000 };

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, context)
    {
        socket_.set_verify_mode(boost::asio::ssl::verify_peer);
        socket_.set_verify_callback(
            boost::bind(&client::verify_certificate, this, _1, _2));

        std::ostream request_stream(&request_);
        request_stream << "GET / HTTP/1.1\r\n";
        request_stream << "Host: www.google.com\r\n";
        request_stream << "Accept: */*\r\n";
        request_stream << "Connection: close\r\n\r\n";


        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 preverified;
    }

    void handle_connect(const boost::system::error_code& error)
    {
        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";
        }
    }

    void handle_handshake(const boost::system::error_code& error)
    {
        if (!error)
        {
            std::cout << "Handshake OK " << "\n";
            std::cout << "Request: " << "\n";
            const char* header = boost::asio::buffer_cast<const char*>(request_.data());
            std::cout << header << "\n";


            boost::asio::async_write(socket_,
                request_,
                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)
        {
            boost::asio::async_read(socket_,
                boost::asio::buffer(reply_, bytes_transferred),
                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: ";
            std::cout.write(reply_, bytes_transferred);
            std::cout << "\n";
        }
        else
        {
            std::cout << "Read failed: " << error.message() << "\n";
        }
    }

private:
    boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket_;
    char reply_[max_length];
    boost::asio::streambuf request_;
};

void add_windows_root_certs(boost::asio::ssl::context &ctx)
{
    HCERTSTORE hStore = CertOpenSystemStore(0, L"ROOT");
    if (hStore == NULL) {
        return;
    }

    X509_STORE *store = X509_STORE_new();
    PCCERT_CONTEXT pContext = NULL;
    while ((pContext = CertEnumCertificatesInStore(hStore, pContext)) != NULL) {
        // convert from DER to internal format
        X509 *x509 = d2i_X509(NULL,
            (const unsigned char **)&pContext->pbCertEncoded,
            pContext->cbCertEncoded);
        if (x509 != NULL) {
            X509_STORE_add_cert(store, x509);
            X509_free(x509);
        }
    }

    CertFreeCertificateContext(pContext);
    CertCloseStore(hStore, 0);

    // attach X509_STORE to boost ssl context
    SSL_CTX_set_cert_store(ctx.native_handle(), store);
}

int main(int argc, char* argv[])
{
    try
    {
        namespace ssl = boost::asio::ssl;

        boost::asio::io_service io_service;

        boost::asio::ip::tcp::resolver resolver(io_service); 
        boost::asio::ip::tcp::resolver::query query("www.google.com", "443");
        boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);

        ssl::context ctx(ssl::context::tlsv12_client);


        add_windows_root_certs(ctx);
        ctx.set_verify_mode(ssl::verify_peer | ssl::verify_fail_if_no_peer_cert);

        // use custom verify_callback here for debugging purposes

        client c(io_service, ctx, iterator);

        io_service.run();
    }
    catch (std::exception& e)
    {
        std::cerr << "Exception: " << e.what() << "\n";
    }

    system("pause");

    return 0;
}

连接成功，我在Wireshark中监控，是真正的SSL连接，我指定的是HTTP/1.1。不知道我在这里错过了什么。

Answer 1

    boost::asio::async_read(socket_,
        boost::asio::buffer(reply_, bytes_transferred),
        boost::bind(&client::handle_read, this,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));

您告诉读取函数缓冲区的大小是 bytes_transferred。那是胡说八道。

使用足够大的缓冲区，重复读取或使用boost::asio::streambuf。

哦。并考虑将 Boost Beast 用于 HTTP 请求