boost::asio with SSL - problems after SSL error

Question

I use synchronous boost::asio SSL sockets in my application. I initialize all parameters and then connect to some hosts (one after another) and do a GET request for each host.

Everything works until I get a "404 - Not Found" error for one of the hosts. After this error, all new connections fail with some unspecified SSL error.

Do I have to reset the ssl::stream somehow? Is it possible to re-initialize the ssl::stream after each connection?

In the following code snippets I removed error handling and all non asio related things.

Main:

asio::io_service ioservice;
asio::ssl::context ctx(ioservice, asio::ssl::context::sslv23);
ctx.set_verify_mode(asio::ssl::context::verify_none);

Connector *con = new Connector(ioservice, ctx);

while (!iplist.empty())
{
    ...
    con->ssl_connect(ipaddress, port);
    ...
}

Connector:

Connector::Connector(asio::io_service& io_service, asio::ssl::context &ctx) 
    : sslSock(io_service, ctx)
{
}

Connector::ssl_connect(std::string ipAdr, std::string port)
{
    ...
    tcp::resolver resolver(ioserv);
    tcp::resolver::query query(ipAdr, port);
    endpoint_iterator = resolver.resolve(query);
    ...

    asio::error_code errorcode = asio::error::host_not_found;
    tcp::resolver::iterator end;

    // Establish connection
    while (errorcode && endpoint_iterator != end)
    {
        sslSock.lowest_layer().close();
        sslSock.lowest_layer().connect(*endpoint_iterator++, errorcode);
    }
    sslSock.handshake(asio::ssl::stream_base::client, errorcode);
    ...
    asio::write(...);
    ...
    asio::read(...);
    ...
    sslSock.lowest_layer().close();
    ...
    return;
}

"some unspecified SSL error" is not very useful information. OpenSSL supplies very good error messages, if you care to check them (eg. ERR_print_errors_fp()). — caf
@caf - Thank you for the info. Asio only writes "SSL error". I will check if OpenSSL has more infos — mspoerr
@Sam Miller: Yes, I have handlers for all return codes and exceptions. — mspoerr
@caf: How can I access the detailed openssl errors from via asio? Is there a special function? asio returns only "ssl error"... — mspoerr
@mspoerr: I haven't used asio, but if it is using OpenSSL underneath, then you should be able to #include <openssl/err.h> and <stdio.h>, then use ERR_print_errors_fp(stderr); to print the error stack to stderr. — caf

mspoerr mspoerr · Accepted Answer · 2010-11-30T23:10:41

I got the answer from the asio mailing list (many thanks to Marsh Ray). Sam Miller was correct in that the asio::ssl::context has to be created each time. To achieve this, std::auto_ptr is used.

Connector.h:

std::auto_ptr<asio::ssl::stream<tcp::socket>> sslSock;

Connector.cpp:

asio::ssl::context ctx(ioserv, asio::ssl::context::sslv23);
ctx.set_verify_mode(asio::ssl::context::verify_none);
sslSock.reset(new asio::ssl::stream<tcp::socket>(ioserv, ctx));

boost::asio with SSL - problems after SSL error

3 Answers