Fixing the Firebase SMS Verification Error: SHA Key Issues Explained

Learn how to troubleshoot Firebase SMS verification errors in your Flutter app by understanding SHA key configurations and package names. --- This video is based on the question https://stackoverflow.com/q/73995372/ asked by the user 'Deniz' ( https://stackoverflow.com/u/15332001/ ) and on the answer https://stackoverflow.com/a/74489854/ provided by the user 'Deniz' ( https://stackoverflow.com/u/15332001/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Flutter firease phone not sending sms due to verification sha key error Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Troubleshooting Firebase SMS Verification Errors in Flutter If you're a Flutter developer working with Firebase for SMS verification, encountering an error message like "A safety_net_token was passed, but no matching SHA-256 was registered in the Firebase console" can be quite frustrating. This problem typically arises when your app's package name and SHA key configurations do not align with the information registered in the Firebase Console. In this guide, we'll explore this issue in detail and guide you through the solution step by step. Understanding the Problem: What Causes the Error? The error message indicates that Firebase is unable to authenticate your application due to mismatched security identifiers. When you set up Firebase for your Flutter app, you must register specific details to ensure proper functionality: Package Name: This is a unique identifier for your application as defined in your pubspec.yaml file. SHA-1 and SHA-256 Keys: These cryptographic keys ensure that requests to Firebase are coming from your application and not from an unauthorized source. If either the package name or the SHA keys in the Firebase Console do not match those of your application, you will encounter the errors preventing SMS verification, even when other functionalities appear to work correctly. Common Error Messages "SMS verification code request failed: unknown status code: 17028" "This app is not authorized to use Firebase Authentication." Steps to Resolve the Issue Now that we understand the cause of the error, let's dive into the solution. Here’s a step-by-step guide to resolving the SHA key mismatch and restoring SMS verification functionality in your Flutter app. Step 1: Verify Your Package Name First, check the package name of your Flutter application. This can be found in your app’s pubspec.yaml file: [[See Video to Reveal this Text or Code Snippet]] Make sure that this is the same as the package name registered in the Firebase Console. Step 2: Add Correct SHA Keys Next, you'll need to gather and add the correct SHA key(s) for your application. Here’s how to do it: Retrieve SHA-1 and SHA-256 Keys: For your app's debug version, you can obtain the SHA keys by running the following command in your terminal (replace <your-key> with your actual key name): [[See Video to Reveal this Text or Code Snippet]] For your release version, make sure you have the release SHA keys generated. Add the Keys to Firebase Console: Navigate to your Firebase project and select Project settings. In the General tab, scroll down to the Your apps section. Under your app, click on the Add Fingerprint button, and enter the SHA-1 and SHA-256 keys. Step 3: Re-Authenticate Your App with Firebase If you’ve changed the package name or made any changes to the SHA keys, you may need to uninstall the app from your device or emulator. This ensures that the new configurations take effect. Uninstall Your App: Remove the app from the device or emulator. Reinstall the App: Reinstall the app, making sure to fetch the latest configurations that correspond with Firebase. Step 4: Test SMS Verification Again Once you have updated the SHA keys and reinstalled the app, try to send an SMS verification code again. With the correct configurations in place, your app should successfully interact with Firebase for authentication purposes. Conclusion Firebase authentication integration can sometimes be tricky, specifically when it comes to aligning your package name and SHA keys. If you encounter the SMS verification error, follow these steps to verify your configuration. Oftentimes, a simple mismatch is the culprit, and correcting it can restore full functionality to your app's authentica