I have a design issue that I've been struggling with in Azure. I have created a .NET Core API and deployed it as an App Service in Azure. On top of that, I have an instance of Azure API Management with oAuth 2 securing it. I was able to achieve this by following this tutorial:
https://learn.microsoft.com/en-us/azure/api-management/api-management-howto-protect-backend-with-aad
So, the API Management instance is secured with policies and rate limiting, but the back-end URL is wide open and requires no authentication. What is the best process to secure the back-end URL?
you can set APIM public IP in accessing whitelist of your App service to make sure only APIM requests will be able to access your App Service. For how to set IP restriction , you may refer to this doc : https://learn.microsoft.com/en-us/azure/app-service/app-service-ip-restrictions#adding-and-editing-ip-restriction-rules-in-the-portal
Related
I have been looking at various tutorials demoing how identity management works as well as API management in azure but I am not seeing an answer to my questions. I understand that managed identities can be used to authorize azure resource to resource communication but I am not seeing how this is done for a web application. Say for example I have an angular website being hosted on an nginx server in an AKS cluster. I understand that I could use Identity management to create Identity resources that make it so that the AKS and APIM are authorized to connect with one another but how would I do this for the angular running application? This application is running in the client's browser, so it seems like this identity management mechanism would not work. How does one secure an APIM so only a given web application can interact with it?
You could secure your API in APIM with the client certificate, then when the app access the API, validate the incoming certificate and check certificate properties against desired values using policy expressions.
For more details, see How to secure APIs using client certificate authentication in API Management.
I'm looking for a way to host a Azure app service behind the Azure API Management without exposing a public url to the app service it self.
The API Management is going to do AD Auth so unauthorized requests are not reaching the app service and waist resources. Same goes for DDos Attacks. Must be terminated by the API Management.
How can I do this? Is the expensive Azure app service environment the only solution?
You could limit the access to your App service to the ip/hostname of the API Management instance. See https://learn.microsoft.com/en-us/azure/app-service/app-service-ip-restrictions
Ddos is hard because what is desired behavior and what is not proberbly depends if the structure of you APIs. But you could limit each subscription key with a limit. See https://learn.microsoft.com/en-us/azure/api-management/transform-api#protect-an-api-by-adding-rate-limit-policy-throttling
In a typical 3-Tier web app, you run web servers in public subnet, while app tier lives in private subnet. Is it possible to run similar architecture with Azure Web apps and Api apps?
I guess you can run Asp.NET Core Web App in Azure Web App and Deploy AspNet Core Web Api to Azure Api App, then make Api end point private so only Web app can talk to it? I see options like Google, Facebook et. as auth providers. Is that what you have to do to make API private?
D.
If you want that level of isolation, one (although expensive) option is an App Service Environment (ASE). Link to docs: https://learn.microsoft.com/en-us/azure/app-service-web/app-service-app-service-environment-intro
App Service Environments are ideal for application workloads requiring:
Very high scale
Isolation and secure network access
The public environment where you deploy by default is public. Your endpoints will be accessible to anyone anywhere, and it is up to your app to do the filtering. This can be done, e.g. through static IP address security settings in Web.config. The problem with that is that even then you can't know for sure what IP address your front-end will use for communication. There are multiple possible addresses it may use for outbound traffic, and those are subject to possible change.
You can see an example of IP restrictions here: restricting IP security
Of course you should also have authentication set up on your API. Documentation links:
https://learn.microsoft.com/en-us/azure/app-service/app-service-authentication-overview
https://learn.microsoft.com/en-us/azure/app-service-api/app-service-api-authentication
In line with what #juunas said above and a slight variant is to introduce Azure API Management Gateway in between Azure web app and Azure Api app. In standard tier API Gateway the IP address is fixed and doesn't change and you can use the API Gateway address in Azure API App web.config to whitelist.
I have an Azure WebAPI and I have added it to Azure API Management.
As well as accessing the API through an API Management URI I note that I can still directly access the Azure API using the URI to the API.
In order to secure the raw API should I:
add code to the API in order to secure it (by treating the API as the ASP.Net application it is and using a certificate)
or
Use some facility of Azure to secure the API
Your choice.
Upload a certificate to API Management, and verify it in your API
Enable basic auth security in API Management and in your backend API
Add a secret to a custom header in API Management and check it in your API.
Check the inbound IP address in your API as an API Management instance will keep the same IP for as long as it is provisioned
Add your API to an Azure VNet and use a network security group to only allow the API Management IP address access to the VNet
I have multiple Web APIs deployed in Azure without applying authentication, so anyone has access to internet has the access to the Web APIs.
Now I would like to apply authentications to the Web APIs, instead of implementing the same authentication logic in different Web APIs, I found Azure API gateway (API management) is a potential solution.
With Azure API management documentation, I learned I can apply policies like validate-jwt to authenticate requests to back end Web APIs. However, endpoints of the back end Web APIs are still available to users.
So, how should I hide them? Must I define a sub network or does Azure API management have a feature for this?
Recently I also had this same problem. Finally I found the solution by using 'IP Restrictions' function. See the following steps:
1) Go to your API management Overview page in Azure portal, copy the VIP.
2) In your Web APP > Networking
3) Paste in your VIP
Microsoft's Solution: How to secure back-end services using client certificate authentication in Azure API Management
Using this approach, any attempt to access a back-end service without the required certificate will result in a 403 - Forbidden response.
You can use a self-signed certificate as opposed to using a trusted CA signed certificate ($$). I chose to implement an Azure Key Vault where I generated a new certificate, downloaded it as a *.PFX file, and uploaded it into my API Management instance as described in the article.
Here is an answer from #PramodValavala-MSFT
https://github.com/MicrosoftDocs/azure-docs/issues/26312#issuecomment-470105156
Here are options:
IP restrictions (as described by #redman)
Function keys
Authentication/Authorization for Functions
Managed Identity for APIM
p.s. in my case I want with IP restrictions since it allows to keep all of the auth on the API Management Gateway.
Or you could use:
Basic auth
Mutual certificate auth
VPN
to secure Azure API Management service communication with your backend service.
Look into setting up TLS on Azure API Management so that all connections to your backend API must come through the API proxy.
Azure API management cannot modify your backend service. It's role is limited to being a proxy.
You will have to apply authentications to each Web API or configure your firewall to accept requests only from Azure APIM.
Is your backend app an Azure Function app or an App Service app?
If so, Managed Identity may be the simplest way to restrict access. No need to store client secrets/certificates in the API Management + not as flaky as IP whitelisting method.
Create an Azure Active Directory Application for the Function App.
Enable Authentication/Authorization module on the Function App and reference the AAD app from step 1.
Enable a Managed Identity on the APIM instance.
Add a <authentication-managed-identity> policy to the APIM and reference the AAD app from step 1.
I've blogged about this approach in more detail in Restrict Azure Functions to API Management with Terraform
Reference:
Use managed identities in Azure API Management
Configure your App Service or Azure Functions app to use Azure AD login