I have a state machine with the following states: create, connect, send,
receive.
When the state sequence is the following: create, connect, send, receive
everything is ok (with my code, sent in the previous email). However when
there is a receive code after connect there is a problem. There is no data
after this receive phase (maybe is not problem) but after that: send
executed successfully and the receive returns with no data.
create
connect
receive : no data, maybe ok
send: ok
receive : no data here !!
create: calls CreateSSL
connect: calls ConnectSSL
send: calls SendSSL
receive: calls ReceiveSSL
What may the problem?
Attila
On Mon, Jun 22, 2020 at 7:35 PM Viktor Dukhovni <openssl-us...@dukhovni.org>
wrote:
> On Mon, Jun 22, 2020 at 03:17:41PM +0200, Attila Csosz wrote:
>
> > char HEADERS[] = "GET /search?q=arduino HTTP/1.1\r\nHost:
> > www.google.com\r\nConnection:
> close\r\n\r\n";
> > char HOST_NAME_PORT[] = "www.google.com:443";
>
> Note the "Connection: close" in the HTTP request header!
>
> > void init_openssl()
> > {
> > SSL_load_error_strings();
> > SSL_library_init();
> > }
> >
> > void CreateSSL()
> > {
> > // Create SSL context
> > meth = SSLv23_client_method();
> > if (!meth) throw Exception("SSL: method");
> >
> > ctx = SSL_CTX_new(meth);
> > if (!ctx) throw Exception("SSL: SSL_CTX_new");
> > old_opts = SSL_CTX_set_options(ctx, SSL_OP_ALL);
>
> The SSL_CTX need only be created once, not once per connection.
> You've made no provision for verifying the server certificate.
> Typically you would load trusted CA certificate locations into
> the SSL_CTX.
>
> > web = BIO_new_ssl_connect(ctx);
> > if (!web) throw Exception("SSL: BIO_new_ssl_connect");
> > }
>
> This code belows in the ConnectSSL function.
>
> >
> > void ConnectSSL()
> > {
> > // Connect
> > res = BIO_set_conn_hostname(web, HOST_NAME_PORT);
> > if (!res) throw Exception("SSL: BIO_ctrl");
> >
> > res = BIO_get_ssl(web, &ssl);
> > if (!res) throw Exception("SSL: BIO_ctrl");
> >
> > res = SSL_set_cipher_list(ssl, PREFERRED_CIPHERS);
> > if (!res) throw Exception("SSL: SSL_set_cipher_list");
> >
> > res = BIO_do_connect(web);
> > if (res <= 0) throw Exception("SSL: BIO_do_connect");
> >
> > res = BIO_do_handshake(web);
> > if (res <= 0) throw Exception("SSL: BIO_do_handshake");
>
> This connection is unauthenticated. Perhaps that's OK, but often it is
> not.
>
> > }
> >
> > void SendSSL()
> > {
> > // Send
> > err = BIO_puts(web, HEADERS);
> > if (err <= 0) throw Exception("SSL: BIO_puts");
> > }
> >
> > void ReceiveSSL()
> > {
> > // Read
> > sResult = "";
> > for (;;) {
> > len = BIO_read(web, buf, sizeof(buf));
> > sResult += buf;
> > if (len <= 0)
> > break;
> > }
>
> The server closes the connection after returning its reply.
> You need to close the SSL BIO to avoid a memory leak.
>
> > ---------
> > It is ok for one request.
> >
> > My problem when I trying to send a new search request to google it works
> > only when I call
> > CreateSSL();
> > ConnectSSL();
> > again
>
> Naturally, you're not doing HTTP/1.1 connection keep-alive, and in any
> case would need to be prepared for the server to close the connection
> now and then. You need an actual HTTPS library, naive open-coding of an
> HTTP client over SSL is unlikely to be correct. Something like libcurl
> or similar is the way to go.
>
> > What may the problem?
>
> You're writing a naïve HTTPS client from scratch. A correct
> implementation would understand "Content-Length" and chunked
> trasfer encoding, handle server-initiated disconnects, be
> prepared to receive multi-record responses, ...
>
> --
> Viktor.
>
