Object Model Permission - sharepoint

I'm trying to confirm my findings on permissions.
In order for the SharePoint object model to be accessed from a console application or for that matter a WinForm application, the user running the application must have db_admin permission to the content database for the web application in question.
In order to use Microsoft.SharePoint.Administration (like calling SPFarm.Local.Solutions.Add) inside an ASP.NET application the following must be true:
The call must be wrapped with RunWithElevatedPrivileges like the following:
SPSecurity.RunWithElevatedPrivileges(delegate() { code to run } );
The user accessing the ASP.NET page must be part of the Farm Adminstrators Group (the page is running under _layouts)
The user in the identity of the App Pool for the web application in question must also be in the Farm Adminstrators Group
Does this information look correct?

Yes but within the web service code you call the functional code using RunWithElevated Privileges this bypasses the identity you are running the web service as and instead uses the SPFarmAdmin user to execute the code.
Alternatively host the web service in an app pool which uses the same domain account as your central admin site, and allow anonymous access to the web service. This would be safe for internal use only and would mean that the web service always had elevated permissions.

Edit: Contrary to Michael's comment I have assumed that this app is not going to be run from within the SP farm.
I would not recommend this approach at all as it is an unupported method of using the SharePoint OM.
You are much better off writing a web service that sits on the SP farm and uses the OM, and then access the web service mehods to perform your required functionality.
You could also look at the out of the box sharepoint web services.
RunWithElevatedPrivileges will not work in your scenario I dont think as it requires a base indetity to fall back on which in the case of code executing on the SP farm is the SP App Pool identity which is usually a farm admin account.
I am happy to be corrected on all of this, but certainly in my environment it would not be wise to invest in a non-standard and unsupported approach to a problem.

Yes the web service will need proper access rights, but this is easier to control with a web service running locally.
However if as you say the apps are always running on the server then using RunWithElevatedPrivileges will solve any permissions issues as you are in effect running that code as an SPFarmAdmin (as long as the app pool identity is configured correctly).
Note: you could use this approach with either bespoke web services or client apps such as console applications or windows forms.

Apologies hobbyman, I never saw you reply.
If you use RunWithElevatedPermissions then it doesn't matter which user the web service runs as, because you are effectivley impersonating a farm admin account.
You could additionally do your own impersonation within the web service and impersonate any user you wish.
Essentially if the web service is running within a given application pool then the web service will run under the indentity which the app pool runs as. Does this clarify things?

Related

Which Identity option in IIS' Application Pool is considered best

Currently all of our web apps have their Application Pool Identity set to ApplicationPoolIdentity. Now, When an app needs to access some resources on some some server, say, add/read some file, the app performs impersonation in code to a user that has permissions to do this stuff. But now, we are contemplating to create a specific user for each app, and set its app pool identity to its specific new user. But I have noticed in the Advanced Settings dialog that Microsoft recommends to use the application pool identity, as shown in the following image:
Why does Microsoft recommends to use this identity, and is using a specific user is not best practice or a wrong move?
thanks,
ashilon
ApplicationPoolIdentity uses a concept called Virtual Accounts
and is implemented to have App Pool isolation.This blog explains
in detail about that .
ApplicationPoolIdentity is the recommended approach to have proper isolation between each website/application pool in IIS7+ onwards.So you can have code or files running for one website or app which cannot be accessed by no one else.
But for your scenario where you need to access resource on another server,When you use ApplicationPoolIdentity it uses the Machine identity only always.So the best approach is to use managed service account
Managed Service Accounts are a great way to manage Services
that need network access. Let Windows take care of passwords and SPNs
for you
Please find more information here ,here
But this has problem as only one managed service account can be assigned to one Server.Even with Application Pool identity,it will be using the $machineaccount to access network resources.
If network resources you have to isolate for each website/application,then your only way to create the separate User Account for each Websites and manage that.
Hope this helps!

How can I use AAD for an Azure version of "Windows Authentication" from a Web App to a Web API App?

I have two applications:
MVC Site (User-facing Web App secured via OAuth -> Google)
Web API Site ("Private" Web Services)
These are hosted in an App Service Plan in Azure. These web services will only be consumed by my own applications - I don't need to worry about outside consumption. In fact, I specifically don't want outside consumption. My Web App is using OAuth to Google - that shouldn't matter here.
So to get to the heart of my question: My web services currently have no authentication/authorization model in the code but I don't want it just publicly available to anybody. On prem, we just lock this down via IIS using Windows Auth and set the service account for the consuming web app to run as a user that Windows Auth allows access to. I'd like to do the equivalent in Azure.
I understand Azure isn't exactly the same but I have to believe this is possible. I have even gotten my web services locked down the way I want using the settings in the Authentication/Authorization tab (I can try to navigate to it but I only get my Swagger UI once I login with a valid organizational account). So half of my battle is solved but I cannot figure out how to do the other half - the equivalent of setting the service account for my consuming MVC application to run as.
Can I do this via the portal without having to code specifically to this scenario? I'd really like a PaaS-level or IaaS-level solution for the security portion of consuming the above locked-down services. I'm also open to other avenues if I'm going down the wrong path in having a PaaS or IaaS security solution to this problem. I'm not against making code changes - we did have a one-liner in our RestSharp code to engage Windows Authentication, but the bulk of the work/configuration was outside of code and that's what I'm going for here.
If going the IaaS path you can host the application inside of an VM in the exact same way as you did before when running it directly on-top of IIS. The benefit is that you can get running the same way as before but you will still need to manage the VM; i.e install updates and take care of its security.
However, if you want to have a PaaS solution, then you need to modify the code of your front-end application to pass on the authentication token to the back-end API, assuming the back-end accepts the same authentication as the front-end. See https://azure.microsoft.com/en-us/documentation/articles/app-service-api-dotnet-get-started/ as an example on how to pass on authentication information from one app to another.
Alternatively you can use the app identity to make calls to your back-end API. This way the calls are not related to any user but are instead done in the context of the app. See https://github.com/Azure-Samples/active-directory-dotnet-daemon for more details on how to set it up, both configuration and needed code.
If you want to allow your users to sign-in using their Google accounts then you could handle authorization to your API using the app identity (second alternative above), assuming the API is independent of the requesting users identity.
Enabling authentication for a Azure Web App directly through the menus in the Azure Portal adds Azure AD authentication in-front of your application and require your to pass an access token generated by Azure AD to your API for it to work.

Which IIS Account should I grant directory access privileges to?

I've moved my codebase to a new directory and need to grant the IIS account read/write privileges on a few folders to allow access by the ASP.Net runtime. I believe NETWORKSERVICE is no longer used for this purpose (as mentioned in this earlier question:
ASP.Net which user account running Web Service on IIS 7?) but, try as I might I can't seem to be able to add the IISAppPool/IIS Worker Process the article links to.
I've found a MyDomain/IIS_WPG account but this isn't the one that is listed in Task Manager for the w3wp process. Can someone help?
UPDATE:
Even odder - the Application Pool for the website in question uses the LocalSystem identity which I thought would be able to access pretty much the entire machine. Is there something incorrect about my basic machine/Windows setup?

IIS Application Pool Recycle

I have to recycle IIS (version 7.5) application pool programatically using c#. When I try to get ApplicationPoolCollection using "ServerManager" class UnauthorizedAccessException raised.
I guess I have to use impersonation. But I don't know to use impersonation. And is there anyway to use impersonation with attribute instead of web.config?
To perform any administrative operations in IIS such as recycling application pools, starting and stopping sites, creating websites and so on, you need to run as administrator.
If you want to programmatically impersonate a user then you need to use the WindowsIdentity.Impersonate method.
There's a reasonably good snippet of sample code there to get you started.
Of course all the usual caveats apply here when it comes to storing credentials for highly privileged users in your web.config file (or hard coded).
Also if you're trying to debug code that accesses IIS programmatically using the managed ServerManager API then make sure you start Visual Studio by doing "Run As Administrator". You need to do this even if your own Windows account is a member of the Administrators group.

How to give Website permission to create further Websites in IIS 7.5?

I'm creating a website in IIS 7.5 (with Windows 7) that needs to be able to create further websites. I've written code that uses Microsoft.Web.Administration to create the website programmatically, and this works fine when I run it as administrator.
Now I'm trying to use the same code in the context of my web application. It fails with the error
Error: Cannot read configuration file due to insufficient permissions
for the file redirection.config (which I understand is located in %WinDir%/System32/inetsrv/config).
I've tried creating a new apppool for this specific website, running under the IIS AppPool[AppPoolName] identity. I've then tried to grant that identity permission to edit the IIS config using
ManagementAuthorization.Grant(#"IIS AppPool\MyAppPool", "Default Web Site", false);
but I still get the same error.
What else should I try?
This probably isn't the wisest approach from a security viewpoint. If this site is hijacked then your attackers will be able to interfere with those files (to no good purpose) or even just delete them.
The way we approached this was to separate website creation tasks into a windows service running with the correct rights to perform these activities. In this service is a remoting end point (although these days you'd probably want to use WCF).
We then created a proxy assembly that is signed and registered in the GAC (it would also need to be marked with the APTCA attribute if you're running at less than Full Trust). This assembly passes on the relevant calls to the remoting endpoint in the windows service from the admin web app/service.
This allows us to run the admin site at least privilege and in partial trust mode. The scope of what can be done by way of site admin tasks is narrowed somewhat by whatever functionality is exposed in the windows service application.
This is a technique known as sandboxing.
I've found a way to do it, but I would very much like to hear expert opinion on whether this is a wise thing to do.
I granted Modify and Write permissions for the IIS AppPool\MyAppPool account to %WinDir%/System32/inetsrv/config and the three .config files inside it.

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