Unable to authenticate using MEWS on FBA site programatically

Question

I am trying to authenticate on my FBA site (On-Prem SP2013) using Content Matrix Extensions Web Service. However, I am getting the below error -

MEWS Url: http://myserver:9090/sites/fbasite/_vti_bin/ml/8.5.0.2/mlspextensions.asmx. Exception: Server was unable to process request. ---> Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)) ---> System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

I am able to successfully authenticate with Native Web Service url - http://myserver:9090/sites/fbasite/_vti_bin/authentication.asmx using this approach.

However, I can see that '/authentication.asmx' does not exist for '/ml/8.5.0.2/' and I also do not see any corresponding Auth or Login method in '/mlspextensions.asmx'

[Note: My FBA site is also having Windows auth enabled.]

Can someone please help with this authentication issue.

Answer 1

I solved the problem by adding the authenticated cookies to my MEWS object as well. This was a miss from my side.

So as a thumb rule, in case of [FBA sites + (NWS or MEWS)] the authenticated cookies have to be added.

    // Sample code snippet
this.websService = new Webs();  // This is a web service
this.websService.Url = siteUrl + "/_vti_bin/Webs.asmx";
this.websService.Credentials = credentials;
this.mewsService = new MLSPExtensionsWebService();  // This is a web service
this.mewsService.Url = siteUrl + "/_vti_bin/ml/" + mewsVersion + "/mlspextensions.asmx";
this.mewsService.Credentials = credentials;
    // Besides URL and credentials there are other initializations as well.
if (cookie != null)
{
    this.websService.CookieContainer = new CookieContainer();
    this.websService.CookieContainer.Add(cookie);

    this.mewsService.CookieContainer = new System.Net.CookieContainer();
    this.mewsService.CookieContainer.Add(cookie);   // This I missed.
}