How to correctly send binary data over HTTPS POST?

Question

I send binary data from client (Debian 6.0.3) to server (Windows Server 2003). To bypass most firewalls I use HTTPS POST. Client and server are implemented usin

Answer 1

(EDIT: I had originally deleted this because I had realised it wasn't using HTTP really. Following a comment where you think you might have a MITM proxy and should use proper HTTP, I'm undeleting/editing.)

POST / HTTP/1.1
User-Agent: my custom client v.1

[binary data]

Whether it's binary data or not, in plain HTTP or with SSL/TLS, you'll need a Content-Length header or to use chunked transfer encoding. This this section of the HTTP spec. A Content-Type header would be useful too.

Chunked transfer encoding is for when you don't necessarily know the length of the stream. (You always need some form of delimiters when sending data, if only to detect reliably when it ends.)

This being said, you should be able to find out whether you're behind a MITM proxy that looks into the application layer on top of SSL/TLS if you get a certificate that's not your servers. If you do still get a successful handshake with your won server cert, there isn't such a proxy. Even an HTTP proxy would use CONNECT and relay everything, without altering the SSL/TLS connection (and thus without altering your original pseudo-HTTP on top).