# How to fix java.security.NoSuchAlgorithmException: Algorithm HmacPBESHA256 not available when building app bundle

## Introduction

In this article, I'll share with you how I fixed a failed `flutter build app bundle` command.

When I ran `flutter build app bundle` in my terminal I got the below error.

```plaintext
Execution failed for task ':app:signReleaseBundle'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.FinalizeBundleTask$BundleToolRunnable
   > Failed to read key upload from store "/Users/<your folder name>/upload-keystore.jks": Integrity check failed: java.security.NoSuchAlgorithmException: Algorithm HmacPBESHA256 not available

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 8s
```

## Solution

The likely cause of this error is that the Java version the app is built with is different from the Java version being used to generate the signing key.

To fix run

```plaintext
Run flutter doctor -v
```

```plaintext
...
[✓] Android toolchain - develop for Android devices (Android SDK version
    34.0.0-rc2)
    • Android SDK at /Users/<your folder path>/Library/Android/sdk
    • Platform android-33, build-tools 34.0.0-rc2
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.11+0-b60-7772763)
    • All Android licenses accepted.

...
```

Prefix the keygen command to point to the Java version used to build your app and run your keygen command as shown below.

```plaintext
/Applications/"Android Studio.app"/Contents/jre/jdk/Contents/Home/bin/keytool -genkey -v -keystore ~/upload-keystore.jks -keyalg RSA -keysize 2048 -validity 10000 -alias upload
```

Run `flutter build appbundle` and your build will be successful

## Connect with me

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