Post requests: Correct http header syntax?

Question

Im using TTURLRequest from the cocoa Three20 development library to form a post request.

I'm setting the http headers with this:

[request setValue:VALUE forHTTPHeaderField:KEY];

I'm getting a 400 response back. I'm also using Charles to capture the requests and responses. The request is getting out (with the headers I had put in) so obviously I'm not forming the headers correctly or I'm missing some important ones.

The Headers I am setting are:

    [request setValue:@"0" 
   forHTTPHeaderField:@"Content-Length"];//0 length?(not sending any raw data)

    [request setValue:authorizationHeader 
   forHTTPHeaderField:@"Authorization"];


 [request setValue:@"CUSTOM/1.0" 
   forHTTPHeaderField:@"User-Agent"];

    [request setValue:@"application/x-www-form-urlencoded" 
   forHTTPHeaderField:@"Content-Type"];

What is the correct syntax and order of http headers in a post request?

Answer 1

The server was throwing an exception while doing some custom filtering causing the server to issue a 400 to the client.