How can I cache credentials in a Web Service? - windows

I have a REST web service running on a Windows 2003 Server. I want to prompt my users from a mobile app to enter their Windows domain credentials. I want to send those credentials to the web service, and cache them for a few days. It appears I can cache the credentials using the low-level Credentials Management functions but everything I've seen so far implies they're made to be called from an interactive session. What's the best way to cache these credentials in a web service?
MORE INFO: The reason why I need to cache the credentials in the Web Service is because I need them to access some back-end resources (i.e. SQL Server, etc.)

You don't typically cache things in a web service.
How are you prompting them to enter their credentials to begin with? That app / piece should cache the information.

It appears that Windows Identity Foundation provides a better mechanism to accomplish what I want. I'll be looking into that.

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How to restrict access to a small user community (IAM users) in GCP / Cloud DNS / HTTPS application

I have a request to restrict the access (access control) to a small user community in GCP.
Let me explain the question.
This is the current set up:
A valid GCP Organization: MyOrganization.com (under which the GCP project is deployed / provisioned)
Cloud DNS (To configure domain names, A & TXT records, zones and subdomains to build the URL for the application).
Oauth client set up (tokens, authorized redirects URIs, etc.).
HTTPS load balancer (GKE -managed k8s service- with ingress service), SSL certificate and keys issued by a trusted CA.
The application was built using python + Django framework.
I have already deployed the application (GCP resources) and it is working smooth.
The thing is that, since we are working in GCP, all IAM users who has a valid userID#MyOrgnization.com can access the application (https://URL-for-my-Appl.com).
Now, I have a new request, which consists in restricting access (access control) to the application only for a small user community within that GCP organization.
For example, I need to ensure that only specific IAM users can access the application (https://URL-for-my-Appl.com), such as:
user1#MyOrganization.com
user2#MyOrganization.com
user3#MyOrganization.com
user4#MyOrganization.com
How could I do that, taking into account the info I sent earlier ?
thanks!
You can use Cloud IAP (Identity Aware Proxy) in order to do that.
Identity-Aware Proxy (IAP) lets you manage access to applications
running in App Engine standard environment, App Engine flexible
environment, Compute Engine, and GKE. IAP establishes a central
authorization layer for applications accessed by HTTPS, so you can
adopt an application-level access control model instead of using
network-level firewalls. When you turn on IAP, you must also use
signed headers or the App Engine standard environment Users API to
secure your app.
Note: you can configure it on your load balancer.
It's not clear in your question if your application uses google auth (but considering that you talk about org-restricted login I think so) - if that's the case you should be able to enable it without virtually touching anything in your application if you are using the Users API.
The best and easiest solution is to deploy IAP (Identity Aware Proxy) on your HTTPS Loadbalancer
Then, grant only the user that you want (or create a gsuite user group and grant it, it's often easier to manage)

is it possible to implement kerberos authentication in azure web app?

We have an application which is hosted on the on-premises Windows server (IIS) server
now I created a windows server on azure and building a web app for it.where the application needs to authenticate the user by windows server (DC) using kerbrose protocol but I couldn't find any documentation regarding this from Microsoft's side
Is the above query possible to be implemented in the azure web app?
No, it's not possible. Windows Authentication is something for on-premise deployments. For Azure Web Sites Azure Active Directory is clearly the best option. Sync from AD to Azure Active Directory is also quite easy to setup.
If you still want to absolutely use Windows Auth and host your website on Azure, you can create Windows VM and host your website there. You then need to join the VM to your AD. To this, both VMs must be in the same network. So if your VM is on-premise you will need to create an site-to-site VPN.
For more information, follow this SO which also discussed about this.
If your intention is to join the VM hosting the website to a domain then as others have mentioned, this isn't possible.
However, doing Kerberos authentication itself within an Azure website isn't particularly difficult, but it does require manual implementation. Windows natively handles all of this for you on domain joined machines and and IIS exposes that functionality. Since you can't domain join you have to manually do all that heavy lifting and request and validate the tickets yourself.
This involves creating a service account in Active Directory and keeping the account password in sync. Once you have that you need to indicate to the browser that it needs to negotiate auth, which is done with the WWW-Authenticate: negotiate header on a 401 response. The client, if configured to send tickets, will send a ticket in the Authorization: Negotiate YII... request header on a subsequent response. At this point you need to shove that negotiate header and that original service account password into something that can validate Kerberos tickets. Windows SSPI will do this for you, but it's a pain. I built a library that'll do this for you: Kerberos.NET. YMMV with what works best for you.
All of that said, it may be more beneficial to switch over to a more modern authentication mechanism like OAuth/OpenIDConnect/SAML.
There are several ways depending on if you have to allow access to users who are associated with a on-premise Active Directory or not.
You should have a look at this service: https://learn.microsoft.com/en-us/azure/active-directory-domain-services/
It will offer an Active Directory within Azure where you can domain join your VM to and then using Kerberos as authentication protocol (should work the same way like on prem).
The other option would be to create a new Active Directory within your Virtual Network (via 1 or 2 small Windows Server VMs where you create the AD).
The good thing if you are using Active Directory Domain Services would be that you could extend it to your on-prem Active Directory by synchronizing or federating your on-prem AD.
There are more informations regarding these scenarios here:
https://learn.microsoft.com/en-us/azure/active-directory/hybrid/whatis-hybrid-identity
For a Azure App Service - Web App you would connect it to your Azure Active Directory (AAD) and use the hybrid identity model to allow users who originate from an on-prem AD access to it:
https://learn.microsoft.com/en-us/azure/app-service/configure-authentication-provider-aad
Hope this helps a bit, it is a rather complicated topic you are digging into.

How to authenticate a web API which runs every hour from a scheduled console application?

I have a requirement where I have to schedule a console application, which fetches certain records from database and calls an ASP.NET web API. Could someone help me with how to restrict the web API to not get called from anywhere else?
Please help me with any useful links, tips, or steps to follow.
There are a few ways you can lock down access to your application for an rpc call.
You can restrict access via IP with IP filtering.
If you're using windows authentication, you can grant permission to specific AD User or Groups in your web config file.
If you're using forms authentication and basically just need to make an RPC call, you can create an endpoint for your console app which accepts a username/password parameter (using https, of course).
If your setup is more advanced, you can use tokens and ASPNET Identity to limit access.
These are just a few ideas. Basically just google ASPNET security and you'll get a ton of ideas.

Auto sign on with Windows Authentication

I am to be having a lot of problems, misinformation and confusion when attempting to find out the plausibility and viability of attempting this.
The requirement is for a remote client, accessing our website to be auto signed in with their Active Directory User account.
We have the option to setup a WCF service (or something similar) on their remote server for authentication purposes. Which from my little understanding is how this problem will be tackled.
So, my question after a little background is this.
CAN this be done, and HOW can it be done?
Instead of hosting a WCF service on their domain, I would look into installing ADFS on their domain.
You can change your website to accept security tokens from ADFS using the WS-Federation protocol. You can use classes from the System.IdentityModel namespace for that. An example of how to implement this in ASP.NET can be found here.
An alternative would be to use Azure Active Directory as your identity provider and have your client sync accounts to their AAD directory (or federate between AAD and ADFS). An example can be found here.

Only allow access to my REST APIs from my own application?

We have a Windows app hosting a WebBrowser control that hits our REST APIs. We like to restrict access to the APIs to be only coming from withing the Windows app itself (for example, the APIs cannot be accessed in a browser, etc).
How can we accomplish that? what is the most secure way without having to expose any kind of credential (for example, if we use HTTP Basic auth, the username and password can be seen by reverse engineering the app itself)?
Thanks a bunch!
EDIT: We plan to distribute the application freely so we have no control over where the connection will be made from.
Restrict the REST interface to only accept connections from 127.0.0.1 (home) and then connect from your rest-consuming application only with http://localhost or http://127.0.0.1 in the URLs (if you use the external IP or DNS name of your machine it'll be treated as a remote connection and denied access).
You can do this with web server settings, or within the code of your REST APIs
I had a similar situation during a project where we distributed an iPhone app that also connected to a REST api that my team developed.
For security we used somewhat of a three-legged scenario. The app was required to authenticate using the user's credentials against a standalone service responsible only for authenticating and generating access tokens. Once the app received a valid access token, subsequent requests to the api required sending this token in the Authorization header.
You could do something similar. If you come up with a credential scheme to authenticate your app as valid API consumers you could use basic auth over HTTPS to obtain tokens, and then only by using those tokens could a consumer gain access to the rest of the API.

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