Android Signature Signatures Android V2 Signatures

Question

I am developing an Android application using version of Android 2.2.2 and gradle version 2.2.2. I am trying to create a signed APK. I made the usual process for creating a signed APK with Android Studio. After that I made the Zipalign process. The generated APK works fine on Android version 6. But in the case of Android N, it shows me an error when installing the APK:

  Failed to install C:\Users\User\AppData\Roaming\Skype\My Skype Received Files\ap p-dev3-release_zipalign.apk: Failure [INSTALL_PARSE_FAILED_NO_CERTIFICATES: Fail ed to collect certificates from /data/app/vmdl25816781.tmp/base.apk: META-INF/CE RT.SF indicates /data/app/vmdl25816781.tmp/base.apk is signed using APK Signatur e Scheme v2, but no such signature was found. Signature stripped?] 

According to the Android studio 2.2 document, he independently takes the sign in the signatures of V1 and V2. Am I doing something wrong? Need help.

Answer 1

The Android plugin for Gradle, as well as Android Studio 2.2 and newer, by default generate APKs that are signed using Signature v1 (JAR) and v2 (APK Signature Scheme v2). Any modification of AP2 with signature v2 invalidates its signature v2, which Android Nougat (Android 7.0) and newer verifies, and thereby prevents the installation of APKs on Android Nougat and newer.

Solutions:

• Do not run zipalign on an already signed APK - Android Plugin for Gradle, and Android Studio will generate already created APP files with a zip index for your release versions.

• If you need to run zipalign, do this before signing the APK. See https://developer.android.com/studio/command-line/zipalign.html and https://developer.android.com/studio/publish/app-signing.html#signing-manually .

• Disable v2 subscription in build.gradle file. See https://developer.android.com/studio/releases/gradle-plugin.html , specifically v2SigningEnabled.