I have install XmlRpcPlugin and HttpAuthPlugin, I am not sure, where exactly is the error. when I connect by my .NET client to the XmlRpc?, I get this exception from request.GetResponse?() (.NET method)
I debugged it by fiddler HTTP debugger and I have found, that trac send wrong Content-Length (23bytes). It sends text "Authentication required" which is exactly 23bytes. But there is small HTML block appended, which cause, that content length is wrong. I can reproduce it with python 2.5 and python 2.7 as well. I have attached the output of fiddler, please see bellow. I find interesting, that the request is made via HTTP 1.1, but in repsonse HTTP 0.9 is mentioned.
POST http://10.250.10.55/mew/login/xmlrpc HTTP/1.1
Content-Type: text/xml
User-Agent: XML-RPC.NET
Host: 10.250.10.55
Cookie: trac_session=2a1a01b9d7d8bcb3db9afc27
Content-Length: 229
<?xml version="1.0"?>
<methodCall>
<methodName>system.methodHelp</methodName>
<params>
<param>
<value>
<string>ticket.getRecentChanges</string>
</value>
</param>
</params>
</methodCall>
HTTP/1.1 401 Unauthorized
Server: tracd/0.12.2 Python/2.7
Date: Wed, 02 Mar 2011 14:07:38 GMT
WWW-Authenticate: Basic realm="Control Panel"
Content-Type: text/plain
Pragma: no-cache
Cache-control: no-cache
Expires: Fri, 01 Jan 1999 00:00:00 GMT
Content-Length: 23
Authentication required<head>
<title>Error response</title>
</head>
<body>
<h1>Error response</h1>
<p>Error code 400.
<p>Message: Bad HTTP/0.9 request type ('<?xml').
<p>Error code explanation: 400 = Bad request syntax or unsupported method.
</body>