How to call SSRS Rest-Api V1.0 with custom security implemented (NOT SOAP) - rest

Question

I have implemented the custom security on my reporting services 2016 and it displays the login page once the URL for reporting services is typed on browser URL bar (either reports or reportserver)
I am using the following code to pass the Credentials
when i use the code WITHOUT my security extension it works and looks like this
ICredentials _executionCredentials;
CredentialCache myCache = new CredentialCache();
Uri reportServerUri = new Uri(ReportServerUrl);
myCache.Add(new Uri(reportServerUri.GetLeftPart(UriPartial.Authority)),
"NTLM", new NetworkCredential(MyUserName, MyUserPassword));
_executionCredentials = myCache;
when i use the code WITH the security extension it doesnt work and looks like this
ICredentials _executionCredentials;
CredentialCache myCache = new CredentialCache();
Uri reportServerUri = new Uri(ReportServerUrl);
myCache.Add(new Uri(reportServerUri.GetLeftPart(UriPartial.Authority)),
"Basic", new NetworkCredential(MyUserName, MyUserPassword));
_executionCredentials = myCache;
and i get an Exception saying "The response to this POST request did not contain a 'location' header. That is not supported by this client." when i actually use this credentials
Is "basic" the wrong option ?
Have anyone done this ?
Update 1
Well it turns out that my SSRS is expecting an Authorisation cookie
which i am unable to pass (according to fiddler, there is no cookie)
HttpWebRequest request;
request = (HttpWebRequest)HttpWebRequest.Create("http://mylocalcomputerwithRS/Reports_SQL2016/api/v1.0");
CookieContainer cookieJar = new CookieContainer();
request.CookieContainer = cookieJar;
Cookie authCookie = new Cookie("sqlAuthCookie", "username:password");
authCookie.Domain = ".mydomain.mylocalcomputerwithRS";
if (authCookie != null)
request.CookieContainer.Add(authCookie);
request.Timeout = -1;
HttpWebResponse myHttpWebResponse = (HttpWebResponse)request.GetResponse();

Answer 1

That's how I got it (SSRS 2017; api v2.0). I took the value for the "body" from Fiddler:
var handler = new HttpClientHandler();
var httpClient = new HttpClient(handler);
Assert.AreEqual(0, handler.CookieContainer.Count);
// Create a login form
var body = new Dictionary<string, string>()
{
{"__VIEWSTATE", "9cZYKBmLKR3EbLhJvaf1JI7LZ4cc0244Hpcpzt/2MsDy+ccwNaw9hswvzwepb4InPxvrgR0FJ/TpZWbLZGNEIuD/dmmqy0qXNm5/6VMn9eV+SBbdAhSupsEhmbuTTrg7sjtRig==" },
{"__VIEWSTATEGENERATOR", "480DEEB3"},
{ "__EVENTVALIDATION", "IS0IRlkvSTMCa7SfuB/lrh9f5TpFSB2wpqBZGzpoT/aKGsI5zSjooNO9QvxIh+QIvcbPFDOqTD7R0VDOH8CWkX4T4Fs29e6IL92qPik3euu5QpidxJB14t/WSqBywIMEWXy6lfVTsTWAkkMJRX8DX7OwIhSWZAEbWZUyJRSpXZK5k74jl4x85OZJ19hyfE9qwatskQ=="},
{"txtUserName", "User"},
{"txtPassword", "1"},
{"btnLogin","Войти"}
};
var content = new FormUrlEncodedContent(body);
// POST to login form
var response = await httpClient.PostAsync("http://127.0.0.1:777/ReportServer/Logon.aspx", content);
// Check the cookies created by server
Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
var cookies = handler.CookieContainer.GetCookies(new Uri("http://127.0.0.1:777/ReportServer"));
Assert.AreEqual("sqlAuthCookie", cookies[0].Name);
// Make new request to secured resource
var myresponse = await httpClient.GetAsync("http://127.0.0.1:777/Reports/api/v2.0/Folders");
var stringContent = await myresponse.Content.ReadAsStringAsync();
Console.Write(stringContent);

Answer 2

As an alternative you can customize SSRS Custom Security Sample quite a bit.
I forked Microsoft's Custom Security Sample to do just what you are describing (needed the functionality at a client long ago and reimplemented as a shareable project on GitHub).
https://github.com/sonrai-LLC/ExtRSAuth
I created a YouTube walkthrough as well to show how one can extend and debug SSRS security with this ExtRSAuth SSRS security assembly https://www.youtube.com/watch?v=tnsWChwW7lA
TL; DR; just bypass the Microsoft example auth check in Login.aspx.cs and put your auth in Page_Load() or Page_Init() event of Login.aspx.cs- wherever you want to perform some custom logging check- and then immediately redirect auth'd user to their requested URI.