HTTP/1.1 407 error with latest Apache HttpClient 4.1.1 when using NTLM authentication

Question

I'm trying to use the Apache HttpClient 4.1.1 library ( http://hc.apache.org/httpcomponents-client-ga/tutorial/html/authentication.html ) to access sites from behind my company's proxy that uses the ISA Server with NTLM authentication but I keep getting an HTTP 407 Proxy Authentication Required error:

Code Snippet

    HttpHost proxy = new HttpHost("myProxyHost", 80, "http");
    DefaultHttpClient httpClient = new DefaultHttpClient();
    httpClient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

    NTCredentials creds = new NTCredentials("myWindowsUserName", "myWindowsPwd", "localhost", "myCompanyDomain");
    AuthScope authScope = new AuthScope("myProxyHost", 80, "", "NTLM");
    httpClient.getCredentialsProvider().setCredentials(authScope, creds);

    HttpHost target = new HttpHost("www.google.com", 80, "http");
    HttpGet get = new HttpGet("/");
    System.out.println("executing request to " + target + " via " + proxy);
    HttpResponse rsp = httpClient.execute(target, get);

    System.out.println("----------------------------------------");
    System.out.println(rsp.getStatusLine());
    Header[] headers = rsp.getAllHeaders();
    for (int i = 0; i<headers.length; i++) {
        System.out.println(headers[i]);
    }
    System.out.println("----------------------------------------");

O/P

executing request to http://www.google.com:80 via http://myProxyHost:80
----------------------------------------
HTTP/1.1 407 Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied.  )
Via: 1.1 myCompanyServer
Proxy-Authenticate: Negotiate
Proxy-Authenticate: Kerberos
Proxy-Authenticate: NTLM
Connection: Keep-Alive
Proxy-Connection: Keep-Alive
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Content-Length: 4120  
----------------------------------------

What am I missing here?

Update: In the same environment, code using the JDK URL and URLConnection classes works!

Working Code Snippet

    System.setProperty("http.proxyHost", "myProxyHost");
    System.setProperty("http.proxyPort", "80");

    URL url = new URL("http://www.google.com");
    URLConnection con = url.openConnection();
    BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
    String inputLine;
    while ((inputLine = in.readLine()) != null)
        System.out.println(inputLine);
    in.close();

O/P

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Answer 1

I had a similar problem with HttpClient 4.1.2. For me, it was resolved by reverting to HttpClient 4.0.3. I could never get NTLM working with 4.1.2 using either the built-in implementation or using JCIFS.

Answer 2

If you have no issues with LGPL licensed software you can try using NTLM engine developed by the Samba JCIFS project instead of the internal one used by Apache HttpClient per default.

See this document for detailed instructions:

http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/src/site/apt/ntlm.apt

PS: JDK URL and URLConnection classes work because they make use of platform specific calls when running on Microsoft Windows