with proxy

Provide your own HttpClient

ADAL communicates with AAD using HttpClient. There are many scenarios where you need to customise this HttpClient, the most common scenario being having to use a proxy server.

Starting with ADAL 4.5.0, a new constructor for AuthenticationContext that takes in an HttpClient has been added.

HttpClient httpClient = CreateCustomHttpClient(); // set a proxy, add headers etc. 

AuthenticationContext authenticationContext = new AuthenticationContext(
      authority: "https://login.microsoftonline.com/common",
      validateAuthority: true, 
      // on .Net and .Net core define your own cache persistence (omitted here for brevity)
      tokenCache: TokenCache.DefaultShared, 
      httpClient: httpClient);

// Now call into ADAL using the standard pattern - AcquireTokenSilent then AcquireToken

This is how to specify a proxy. For more details see the MSDN docs.

var proxy = new WebProxy()
{
    Address = new Uri("localhost:8080"),
    BypassOnLocal = false,
    UseDefaultCredentials = false,

    // *** These creds are given to the proxy server, not the web server ***
    Credentials = new NetworkCredential(
        userName: "proxyUserName",
        password: "proxyPassword");
};

// Now create a client handler which uses that proxy
var httpClientHandler = new HttpClientHandler()
{
    Proxy = proxy,
};

// Finally, create the HTTP client object
var client = new HttpClient(handler: httpClientHandler, disposeHandler: true);

For reference, this is how ADAL configures its HttpClient if you don't specify one:

var httpClient = new HttpClient(new HttpClientHandler() { UseDefaultCredentials = true })
{
    MaxResponseContentBufferSize = 1 * 1024 * 1024 // 1 MB
};

httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

Older versions

Previous to ADAL 4.5.0 ADAL.NET does not propose any API to set a proxy, however you can use the system level API: the HttpClients used by ADAL.NET are able to use it.

using System.Net;
...
{
 // Set the proxy
 IWebProxy proxy = new WebProxy("http://proxyserver:80", true);
 // This does not work on .Net Core https://github.com/dotnet/corefx/issues/7037
 WebRequest.DefaultWebProxy = proxy; 

 // Use ADAL.NET
}