This sample demonstrates how to verify the response received from the SafetyNet service.
It shows how to extract the compatibility check response from the JWS message, validate its SSL certificate chain, hostname and signature.
This check can be done completely offline (See
OfflineVerify.java) or by using the Android Verification API to verify the content and signature of the response (see
OnlineVerify). This REST API requires you to register at the Google Developers console and register for an API key. Detailed steps are available [in the documentation] under Validating the response with Google APIs.
Note that this sample only provides a basic overview over the verification process and does not cover all possibilities. For example,it is reccomended to always verify the nonce in the request as well. This sample also does not show the app-to-server communication.
For more details, see the guide at https://developer.android.com/training/safetynet/index.html#verify-compat-check .
This sample only demonstrates verification of the server response. The next step is to verify that the attestation response matches the request by verifying their contents, including the package name, digest, timestamp and nonce.
This step is crucial. If you do not verify the response and request, you may be vulnerable to a replay attack, in which an attacker can replay an old attestation response from a different device or app.
This sample uses the Gradle build system, but can also be easily build with any IDE or with any build tool.
To build this project using the provided gradle scripts, use the "gradlew build" command and then run these special run tasks where you can specify the signed statement as a paramter:
gradlew runOfflineVerify -PsignedStatement=...
gradlew runOnlineVerify -PsignedStatement=...
Online verification requires an API key for the Android Verification API. Follow the steps in the documentation under "Validating the response with Google APIs" and add the API key into the
API_KEY field at the top of
If you are not using Gradle, you can also build this sample with any other build system and run it directly from the commandline, adding the signed stament as a paramter. Just be aware that the
OnlineVerify.java requires the Google HTTP Client Library for Java.
If you've found an error in this sample, please file an issue: https://github.com/googlesamples/android-SafetyNetSample
Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
Copyright 2016 Google Inc.
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