TamperNotifications

This sample is to demonstrate how Tamper Notifications mechanism works.

Description

https://dexprotector.com/docs#tamper-notifications

Requirements

• Android Studio or Gradle
• DexProtector Enterpise with a valid license

Configuring

• Set path to Android SDK in local.properties
• Set path to DexProtector Enterprise in build.gradle (project’s root) instead of /Users/developer/DexProtector

Building

Open the project in Android Studio and execute Build -> Generate Signed APK.. command or execute gradle clean assemble from the command line. A protected APK file will be placed into app/app-release.apk if you use Android Studio, if you use gradle via command line a protected file will be available at app/build/outputs/app-release.apk. Either approach you use, we refer to the protected file as app-release.apk below.

Evaluating

Note: All the actions are to be performed from the project's root

Original APK

Install the protected application to a device or an emulator and launch it. There should be a following message displayed: Tamper detection result: false

Updating a file inside of the APK

cp app-release.apk app-release-copy.apk
mkdir assets
echo 1 > assets/sample.txt
zip -g  app-release-copy.apk assets/sample.txt
zip -d  app-release-copy.apk META-INF/*
jarsigner -verbose  -digestalg SHA1 -keystore sample.keystore  app-release-copy.apk  -storepass android -keypass android android
zipalign -v -f 4  app-release-copy.apk  app-release-modified.apk

After installation and launching of app-release-modified.apk there should be a message displayed: Tamper detection result: true

Adding a file into the APK

cp app-release.apk app-release-copy.apk
echo 1 > test.dat
zip -g app-release-copy.apk test.dat
zip -d app-release-copy.apk META-INF/*
jarsigner -verbose  -digestalg SHA1 -keystore sample.keystore app-release-copy.apk  -storepass android -keypass android android
zipalign -v -f 4  app-release-copy.apk  app-release-modified.apk

After installation and launching of app-release-modified.apk there should be a message displayed: Tamper detection result: true

Deleting a file from the APK

cp app-release.apk app-release-copy.apk
zip -d app-release-copy.apk assets/sample.txt
zip -d app-release-copy.apk META-INF/*
jarsigner -verbose  -digestalg SHA1 -keystore sample.keystore app-release-copy.apk  -storepass android -keypass android android
zipalign -v -f 4  app-release-copy.apk  app-release-modified.apk

After installation and launching of app-release-modified.apk there should be a message displayed: Tamper detection result: true

Resigning with a different certificate

Notifications will be fired with the following settings only (otherwise the protected application will fail to start because of the DexProtector's internal integrity checks that prevent starting of a modified APK):

<integrityControl>
  <checkCertificate>off</checkCertificate>
</integrityControl>

Prior to this step, please delete the application from a device/emulator

cp app-release.apk app-release-copy.apk
zip -d app-release-copy.apk META-INF/*
jarsigner -verbose  -digestalg SHA1 -keystore test.keystore app-release-copy.apk  -storepass android -keypass android android
zipalign -v -f 4  app-release-copy.apk  app-release-modified.apk

After installation and launching of app-release-modified.apk there should be a message displayed: Tamper detection result: true