I have a Silverlight 5 app that runs on a SharePoint 2007 site. The Silverlight app gets a bunch of data from SharePoint lists using the Lists.asmx service. The main site is secured using NTLM security and Silverlight is able to successfully call the web services without having to eplicitly set anything to do with authentication. We extended the SharePoint site to a second domain that uses asp.net FormsBasedAuthentication. On this version of the site, the first web service call fails with a 403 Forbidden response and the exception:
System.ServiceModel.CommunicationException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
As I understand it, this is a generic message and not the true exception. Well, obviously we need the real exception to have any idea what the problem is. This MSDN page (Creating and Handling Faults in Silverlight) offers two solutions to getting the real exception.
The first is to modify your WCF service to return an alternate HTTP status code. This doesn't work because for one, it is not a WCF service, it's an .asmx web service so I can't add the suggested WCF behavior to modify the status code. Second, it's SharePoint's service so I can't do much to modify it anyway. Could I modify IIS to achieve an equivalent solution somehow?
The second solution is to register an alternative HTTP stack in the Silverlight application. I tried this out and found out the "real" exception was an authentication exception. So I went down dead ends trying to figure out out to get authenticated for about 24 hours only to finally find out that normally, the ASP.NET authentication cookie is passed with the service request, unless you are using the Client HTTP stack. So registering the client HTTP stack allowed me to see real exceptions, but it created its own exception which seems to only be fixed by not using the Client HTTP stack...
I believe have verified with Fiddler that the authentication cookie is being sent when using the default HTTP stack. I don't know if the Lists.asmx service is unable to use it and is giving an authentication error anyway, or if there is some other exception. How can I determine the cause of the "The remote server returned an error: NotFound." exception?
Well, this isn't a good answer to the quesion "How can I determine the cause..." but it's what worked for me. What I did was open up STSSOAP.dll, the assembly containing the Lists service implemention, in reflector. I copied the relevant code to implment my own GetListItems method in my own service. Luckily, the actual Lists.GetListItems method code was minimal and just called other SharePoint methods and even luckier, those methods & members are all declared public so I was able to do this. I then replaced Lists.asmx with my version on the server and attached the debugger to get some info. What I found was my authentication cookie was being used and HttpContext.Current.Session.User.Identity.IsAuthenticated was true. So it knew I was logged in. But I was still getting an authentication error which I could see farther down in SharePoint's code, was converted to a 403.
So I know asp.net considers me authenticated but SharePoint says I don't have permissions. But the service account the app pool is running under is a SP admin so why don't I have permissions? So next I inspected the SPContext.Current.Web.User; SharePoint's current user. It was null! In other words, as far as SharePoint is concerned, I'm still logged in as an anonymous user because I haven't explicitly logged in with a domain user, and an anonymous user doesn't have permissions on the list I'm accessing or most of the rest of the API. The answer by Sean McDonough to this quesion lays it out.
Basically I need to run the involved code with elevated privileges to get the code to run under the asp.net service account that I originally thought it was running under. If using the API, you can use the RunWithElevatedPrivileges delegate. But if you're calling the web services, you can't do that. The few options I could think of were:
Call the services on the base site that uses Windows Authentication. This would require me to embed the credentials in the client-side Silverlight application which is a security threat so I nixed this one.
Implement my own web service to get the data for me.
The web service could access the list using the SharePoint API and
RunWithElevatedPrivileges.
The web service could call the Windows Authentication site's services passing the current credentials or other embedded credentials.
For implementation ease, all I've done so far is the second option under number 2 and it's working. However, it is clunky and I may change to option 1 which I expect will also work.
Related
I'm trying to use WSO2 API Manager 1.10.0 on an existent micro-services project with REST APIs following WSO2 tutorial.
I have installed it on my computer as well as a copy of my application and configured AM to manage requests (GET, POST and DELETE) to my resource but I always obtain a "Response code 0" with Response Header
{
"error": "no response from server"
}
Trying to contact my application using Advanced REST Client I obtain 200 with the correct result.
My APIs use a token inside the header to authenticate the user passed so I have implemented a dummy API without authentication but I still have the same issue.
I have tried also the Cloud version with our test server but still obtaining the same result.
I found this guide http://wso2.com/blogs/cloud/video-setting-up-custom-url-for-api-store-and-gateway/ but I don't know if this can be a solution for the problem in localhost.
Setting up the custom url in WSO2 API Cloud wont help. Thats there for a different purpose. There are two things you can do.
If you are interested in going ahead with the cloud version, you can get help from them. You can send a support request and the cloud team will help.
You can troubleshoot your local instance. When doing so, first, try to invoke your api via curl and see whether it gets a response. Sometime, your api can work fine, but due to some reasons, the result might not reach the api console.
If the curl works fine or not, you can check the logs to see whether there are any errors printed. Some more questions:
Is your backend service exposed via http or https?
If it is https, then if its certificate is not a CA signed one, API Manager will fail during the handshake. If so, you will have to add the cert to api managers client-truststore.jks
In the cloud scenario, your backend should be accessible from internet and the certificate story is valid for cloud too.
Are you trying to access the api using swagger console (or any web application). There are couple of reasons you could encounter this issue. one could be certificate not installed in the browser.
If this happens you should see some error log in the api manager console (something related to CA not found). for that first you can copy the backend url (swagger console shows the url it used to send the request) and paste it on a new browser window and install the certificate to the browser.
also you can get an idea about the issue by using a tool like firebug and check the request. (it will show the error for not connecting the AM)
Finally I have found the issue: the API Manager does not accept plain text response, responding using a JSON solves the problem.
Using other mediatype such as XML or TEXT/HTML it reports 406, with text plain it returns Error 0.
I have a web reporting tool lets say Business Objects, Cognos, OBIEE, Crystal Reports. I want to display some data into the report which is coming from a Web Service. So i copy paste the Web service URL inside the report cell and i can access the data.
However this leaves a big security issue as i cannot authenticate the requestor. One thing which i can think of is checking the Http header request: referer property which is set by the reporting tool in my Web Service. This atleast ensures that the request has originated from my Reporting Application. Besides this i cannot see how i can authenticate a specific user.
Appending Username in the Web Service URL is also not an option because one report is used by many users. I would somehow want to access this specific user session and associate the web service request with this user session. Lets say both my Web Reporting tool and web service are running on the same Web Application Server. Is it possible to merge the Web Service Provider and my Reporting Application so that the session user name is available in the WebService ?
Hey there code warriors and stack exchangers.
I have been trying in vain to set credentials for a web service. I wrote the webservice in Websphere (java ee) and it requires a username and password in the header for any of the services to be called. I can run it fine in SOAP UI, but I need to be able to hit it from a .net web client.
So far I have tried setting the credentials like so...
dlc.ClientCredentials.UserName.UserName = "idiotCreds";
dlc.ClientCredentials.UserName.Password = "someWhackyPWD";
And so far I have just recieved this exception
security.wssecurity.WSSContextImpl.s02: com.ibm.websphere.security.WSSecurityException: Exception org.apache.axis2.AxisFault: CWWSS6500E: There is no caller identity candidate that can be used to login. ocurred while running action: com.ibm.ws.wssecurity.handler.WSSecurityConsumerHandler$1#42304230
Which I am guessing is telling me that there are no credentials being set...
Even though I set the client credentials. Do I need to create and add a soap header manually here? I thought that was supposed to be handled by that client object? Any ideas fellas? Thanks
The question and answer in this SO thread will provide those who seek answers with the solutions they need.
https://stackoverflow.com/a/12159837/729820
We're having a hard time figuring how these credentials objects work. In fact, they may not work how we expected them to work. Here's an explanation of the current issue.
We got 2 servers that needs to talk with each other through webservices. The first one (let's call it Server01) has a Windows Service running as the NetworkService account. The other one Server02 has ReportingServices running with IIS 6.0. The Windows Service on Server01 is trying to use the Server02 ReportingServices WebService to generate reports and send them by email.
So, here's what we tried so far.
Setting the credentials at runtime (This works perfectly fine):
rs.Credentials = new NetworkCredentials("user", "pass", "domain");
Now, if we could use a generic user all would be fine, however... we are not allowed to. So, we are trying to use the DefaultCredetials or DefaultNetworkCredentials and pass it to the RS Webservice:
rs.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials
Or:
rs.Credentials = System.Net.CredentialCache.DefaultCredentials
Either way won't work. We're always getting 401 Unauthrorized from IIS. Now, what we know is that if we want to give access to a resource logged as NetworkService, we need to grant it to DOMAIN\MachineName$ (http://msdn.microsoft.com/en-us/library/ms998320.aspx):
Granting Access to a Remote SQL Server
If you are accessing a database on another server in the same domain (or in a trusted domain), the Network Service account's network credentials are used to authenticate to the database. The Network Service account's credentials are of the form DomainName\AspNetServer$, where DomainName is the domain of the ASP.NET server and AspNetServer is your Web server name.
For example, if your ASP.NET application runs on a server named SVR1 in the domain CONTOSO, the SQL Server sees a database access request from CONTOSO\SVR1$.
We assumed that granting access the same way with IIS would work. However, it does not. Or at least, something is not set properly for it to authenticate correctly.
So, here are some questions:
We've read about "Impersonating Users" somewhere, do we need to set this somewhere in the Windows Service ?
Is it possible to grant access to the NetworkService built-in account to a remote IIS server ?
Thanks for reading!
All details you need are included in this very old article
In short, when you find it confusing to troubleshoot issues like this, you should first review the technical details behind ASP.NET impersonation carefully.
Here are some things you could check out:
- set an SPN (Service Principal Name) for the reporting service; you can find good examples in google;
- Allow delegation (ClientCredentials.Windows.AllowImpersonationLevel)
Is the problem that you're failing to authenticate to IIS, or failing to authenticate to SSRS? The DOMAIN\MachineName$ account may need to be granted permission in SSRS to run the report you're trying to automate.
SSRS usually does a pretty good job of getting IIS configured correctly, so you shouldn't need to mess with those settings. I double-checked my installation (which is SSRS 2005, things may have worked differently in SSRS 2000 and you didn't say which version you're running), and it's set to use Windows authentication and has impersonation enabled. That means IIS should basically just be authenticating your credentials (validating a correct username/password), not authorizing (determining whether that user has permission to run the report in question). IIS then passes the credentials on to SSRS, which has its own settings for determining what accounts have permission to view reports.
Also, you can automate sending reports on a scheduled basis directly in SSRS, so you may not need the Windows service at all if your scheduling is fairly basic (i.e., daily, weekly, etc.).
Case 1. When I browse a little test site from my own PC called JOHNXP (e.g. http://localhost/WebClient ), my .aspx page invokes my ASMX webservice picks up my credentials and passes them across to another webservice on ANOTHER machine (SERVERTRIM) in the same domain. I can see my request resulting in a Security Log entry on the SERVERTRIM machine with my credentials.
Case 2. I move to another PC in the same domain and logon with the same credentials I used back at my personal desktop. When I browse the same test site above (this time as http://johnxp/WebClient ), I get this percolated back to my .aspx page:
System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Net.WebException: The request failed with HTTP status 401: Unauthorized
Looking at the Security Log on SERVERTRIM, I note that the access in case 2 resulted in an ANONYMOUS LOGON which seems to explain the 401 / Unauthorized.
I'm trying to get my webservice to use the credentials of the logged in DOMAIN user when my WS calls a vendor's webservice on a different server.
My ASMX webservice runs on my desktop (IIS 5.1 WinXP Pro - machine name is JOHNXP). I have Enable anonymous UNCHECKED in every server involved and I have this in every web.config involved in my scenario:
The vendor webservice runs on SERVERTRIM (Win 2003 Server) and it is also ASMX and uses WSE 3.0.
Wireshark and Netmon look too formidable as tools for me right now. I am figuring the different resulting LOGONs on the "remote" server (SERVERTRIM) are sufficient "evidence". All machines above are in the same domain but I want to keep the "remote" webservice on SERVERTRIM and my intermediate webservice on a different server in the same domain if possible. Does this scenario demand that I have to dig into "delegation"? What would be the easiest tool to monitor why the same credentials result in an ANONYMOUS LOGON when the web request is initiated on another machine in the domain?
My knowledge of authentication is a bit hazy, but if I understood your description correctly:
in the first case, you're browsing to localhost, which is impersonating the caller, then calling a web service on a different machine. The impersonation is being done on the same machine as the client. I believe in this case, the impersonating application doesn't need to be on a machine that is trusted for delegation (because it's already the same machine as the client).
in the second case, you're browsing to a different PC, which is attempting to impersonate the caller when calling a third PC. In this case, the PC in the middle would need to be trusted for delegation (which it presumably won't be if it's a development workstation).