quickstart asp.net token check

This document provides a quickstart guide for integrating Approov API security into your ASP.Net backend. Approov verifies that requests originate from trusted mobile app versions, enhancing your API's security. This guide covers setting up the Approov CLI, registering your API domain, configuring keys (symmetric and asymmetric), adding dependencies, and implementing the Approov token middleware in your ASP.Net application. Further details and troubleshooting are linked within.

Approov QuickStart - ASP.Net Token Check

Approov is an API security solution used to verify that requests received by your backend services originate from trusted versions of your mobile apps.

This repo implements the Approov server-side request verification code for the ASP.Net framework, which performs the verification check before allowing valid traffic to be processed by the API endpoint.

Approov Integration Quickstart

The quickstart was tested with the following Operating Systems:

First, setup the Approov CLI.

Now, register the API domain for which Approov will issues tokens:

NOTE: By default a symmetric key (HS256) is used to sign the Approov token on a valid attestation of the mobile app for each API domain it's added with the Approov CLI, so that all APIs will share the same secret and the backend needs to take care to keep this secret secure.

A more secure alternative is to use asymmetric keys (RS256 or others) that allows for a different keyset to be used on each API domain and for the Approov token to be verified with a public key that can only verify, but not sign, Approov tokens.

To implement the asymmetric key you need to change from using the symmetric HS256 algorithm to an asymmetric algorithm, for example RS256, that requires you to first add a new key, and then specify it when adding each API domain. Please visit Managing Key Sets on the Approov documentation for more details.

Next, enable your Approov admin role with:

For the Windows powershell:

Now, get your Approov Secret with the Approov CLI:

Next, add the Approov secret to your project .env file:

Now, add to your appname.csproj file the dependencies:

Next, in Program.cs load the secrets from the .env file and inject it into AppSettiongs:

Now, let's add the class to load the app settings:

Next, add the ApproovTokenMiddleware class to your project:

NOTE: When the Approov token validation fails we return a 401 with an empty body, because we don't want to give clues to an attacker about the reason the request failed, and you can go even further by returning a 400.

Not enough details in the bare bones quickstart? No worries, check the detailed quickstarts that contain a more comprehensive set of instructions, including how to test the Approov integration.

More Information

System Clock

In order to correctly check for the expiration times of the Approov tokens is very important that the backend server is synchronizing automatically the system clock over the network with an authoritative time source. In Linux this is usually done with a NTP server.

Issues

If you find any issue while following our instructions then just report it here, with the steps to reproduce it, and we will sort it out and/or guide you to the correct path.

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Useful Links

If you wish to explore the Approov solution in more depth, then why not try one of the following links as a jumping off point:

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