A Java reverse-engineering utility for analyzing and rebuilding Android APK/APKS packages that use Google Play PairIP protection.
Current version: 1.4.14 | Language: Java 17 | Build: Gradle + Shadow Jar
--- ## Overview RePairip is a command-line tool that works with PairIP-protected Android packages. It can merge split `.apks` packages, patch PairIP-related dex code, clean split metadata from the manifest, rebuild the APK, and optionally apply a static translation JSON to restore dumped PairIP values. The project focuses on two workflows: - **Dynamic dump/logging workflow**: merge an `.apks`, inject logging support, patch PairIP launcher/signature logic, rebuild the APK, and preserve selected dex CRC values. - **Static translation workflow**: take a merged APK plus a `pairip.json` translation file, rewrite PairIP classes, restore strings/method references, remove unused PairIP runtime pieces, and rebuild a translated APK. The dex rewriting logic is built on top of the open-source [smali/dexlib2](https://github.com/JesusFreke/smali) ecosystem. --- ## Screenshots | App UI | Dump Style | | --- | --- | |  |  | --- ## Features - Loads normal `.apk` files and split `.apks` bundles. - Merges split APK modules into a single APK with `ARSCLib`. - Patches `AndroidManifest.xml` split metadata and PairIP license components. - Injects helper dex code from embedded resources: - `log.dex` - `restoreMethod.dex` - Patches PairIP startup and license classes. - Adds a `PairipLog` helper with an app-specific dictionary path. - Detects simple PairIP junk holder classes. - Inserts a `StartupLauncher.pairip()` call after `VMRunner.invoke()`. - Rewrites signature/integrity checks to return safe values. - Applies translation data from a JSON file. - Extracts embedded dex payloads from top-level PairIP assets when needed. - Removes `libpairipcore.so` during translation patching. - Rebuilds final APK output beside the input file. --- ## Requirements - JDK 17 or newer - Gradle wrapper included in this repository - A PairIP-protected `.apks` or already merged `.apk` --- ## Build ### Windows ```bat gradlew.bat assemble ``` ### Linux / macOS ```bash ./gradlew assemble ``` The final jar is generated here: ```text antik/build/libs/RePairip.jar ``` The jar entry point is: ```text com.antik.Main ``` --- ## Usage ### 1. Merge and patch an APKS bundle ```bash java -jar antik/build/libs/RePairip.jar -i input.apks ``` This flow: - extracts the `.apks` bundle into a temporary directory - merges split APK modules - patches manifest split/license metadata - patches dex files for PairIP logging and launcher behavior - writes a merged output APK - writes a PairIP-patched output APK Expected output names: ```text input_merged.apk input_merged_pairip.apk ``` ### 2. Apply a translation JSON to an APK ```bash java -jar antik/build/libs/RePairip.jar -i input.apk -t pairip.json ``` This flow: - loads the APK - reads `pairip.json` - rewrites selected PairIP classes - restores static string/method values - adds required embedded dex payloads when needed - removes native PairIP runtime library entries - writes a translated APK Expected output name: ```text input_translated.apk ``` --- ## Translation JSON Format The translation file is a JSON object keyed by class name. Each class entry contains a value `type` and a `fields` object. Example: ```json { "com.example.SomePairipHolder": { "type": "java.lang.String", "fields": { "a": "restored value", "b": "another restored value" } }, "Lcom/example/MethodHolder;": { "type": "java.lang.reflect.Method", "fields": { "m0": "com.example.Target->methodName(java.lang.String):void" } } } ``` Supported type forms include: ```text java.lang.String Ljava/lang/String; java.lang.reflect.Method Ljava/lang/reflect/Method; ``` Class names can be written as Java-style names or dex descriptors: ```text com.example.ClassName Lcom/example/ClassName; ``` --- ## How It Works ### Full Pipeline ```text // RePairip high-level flow // // input // | // +----------+----------+ // | | // .apk .apks // | | // | +------v------+ // | | Extract | // | | Splits | // | +------+------+ // | | // | +------v------+ // +------------->| Merge APK | // +------+------+ // | // +---------v----------+ // | Patch Manifest | // | - split metadata | // | - license entries | // +---------+----------+ // | // +-----------v------------+ // | Translation provided? | // +-----------+------------+ // yes | no // | // +---------------------+--------------------+ // | | // +------v------+ +-------v-------+ // | Rewrite | | Logging Patch | // | PairIP dex | | + Dex Patch | // +------+------+ +-------+-------+ // | | // +------v------+ +-------v-------+ // | Add restore | | Patch CRC32 | // | dex/assets | | if available | // +------+------+ +-------+-------+ // | | // +---------------------+--------------------+ // | // +------v------+ // | Build APK | // +------+------+ // | // output ``` ### Dynamic Dump / Logging Patch ```text // Before // // app start // | // +-------v--------+ // | StartupLauncher | // | launch() | // +-------+--------+ // | // +-------v--------+ // | VMRunner.invoke | // +-------+--------+ // | // return // // // After // // app start // | // +-------v--------+ // | StartupLauncher | // | launch() | // +-------+--------+ // | // +-------v--------+ // | VMRunner.invoke | // +-------+--------+ // | // +-------v--------+ // | pairip() | // | dump/log values | // +-------+--------+ // | // return ``` ### Static Translation Patch ```text // Before // // PairIP classes // | // +---------v----------+ // | Obfuscated fields | // | VM/runtime restore | // +---------+----------+ // | // runtime lookup // | // return // // // After // // pairip.json // | // +---------v----------+ // | TranslationData | // | class -> fields | // +---------+----------+ // | // +---------v----------+ // | TranslationRewriter| // | restore statically | // +---------+----------+ // | // +---------v----------+ // | Clean PairIP flow | // | remove runtime lib | // +---------+----------+ // | // translated APK ``` ### Manifest Patch ```text // AndroidManifest.xml cleanup // // manifest/application // | // +----------v-----------+ // | Remove split flags | // | requiredSplitTypes | // | splitTypes | // | isSplitRequired | // | isFeatureSplit | // +----------+-----------+ // | // +----------v-----------+ // | Remove Play metadata | // | vending splits | // | stamp source/type | // +----------+-----------+ // | // +----------v-----------+ // | Remove PairIP license| // | activity/provider | // | CHECK_LICENSE perm | // +----------+-----------+ // | // patched manifest ``` ### Signature / Integrity Patch ```text // Target methods // // verifySignatureMatches() // verifyIntegrity() // // // Before: // // entry // | // +-----v------+ // | original | // | validation | // +-----+------+ // | // result // // // After: // // entry // | // +-----v------+ // | fixed safe | // | return | // +-----+------+ // | // true / void / null ``` ### Class Rewrite Map ```text // Translation mode class handling // // Lcom/pairip/Application; -> clean constructor + clinit // Lcom/pairip/StartupLauncher; -> launch + restoreString + restoreMethod // Lcom/pairip/VMRunner; -> private constructor + invoke returns null // Lcom/pairip/licensecheck3/...; -> clean constructor + no-op activity hook // Other com/pairip/* classes -> removed unless explicitly kept ``` --- ## Project Structure ```text RePairip/ ├── antik/ │ ├── build.gradle.kts │ └── src/main/ │ ├── java/com/antik/ │ │ ├── Main.java │ │ ├── AntikUtils.java │ │ ├── DexPatcher/ │ │ │ ├── DexPatcher.java │ │ │ ├── MethodT/ │ │ │ ├── PairipMethodMake/ │ │ │ └── Translation/ │ │ ├── crc32/ │ │ ├── manifest/ │ │ ├── ui/ │ │ └── utils/ │ └── resources/ │ ├── log.dex │ ├── restoreMethod.dex │ └── info.txt ├── gradle/ ├── preview/ ├── build.gradle.kts ├── settings.gradle.kts └── README.md ``` --- ## Important Source Files | File | Purpose | | --- | --- | | `Main.java` | CLI argument parsing and main APK/APKS workflow | | `manifestP.java` | Manifest split/license metadata cleanup | | `DexPatcher.java` | Dynamic logging dex patch flow | | `patchLauncher.java` | Rebuilds `StartupLauncher` and creates `pairip()` | | `patchLaunchMethod.java` | Inserts `StartupLauncher.pairip()` after `VMRunner.invoke()` | | `patchM.java` | Rewrites signature/integrity methods | | `TranslationPatcher.java` | Static translation patch workflow | | `TranslationData.java` | Parses and normalizes `pairip.json` | | `TranslationRewriter.java` | Rewrites known PairIP classes | | `crc32.java` | Copies dex CRC values from merged source APK to patched APK | --- ## Dependencies | Dependency | Use | | --- | --- | | `org.smali:dexlib2` | Read and write dex classes/methods/instructions | | `com.github.REAndroid:ARSCLib` | Load, merge, patch, and write APK/APKS modules | | `com.google.guava:guava` | Utility dependency | | `com.gradleup.shadow` | Build the runnable fat jar | --- ## Notes - RePairip writes generated APK files beside the input file. - Temporary APKS extraction folders are deleted after processing. - APK signing is not handled by this tool. Sign the rebuilt APK with your preferred Android signing workflow. - Results can vary by PairIP version and app build layout. - If you find a bug, open an issue with the input type, command, stack trace, and expected behavior. --- ## Contributing Contributions are welcome. Good areas for improvement include: - better PairIP version detection - stronger translation JSON validation - more detailed error messages - test APK fixtures - signing workflow documentation - additional dex rewrite strategies Please keep patches focused and include enough detail to reproduce any bug you fix. --- ## License This project is distributed under the Apache License 2.0. ```text Apache License Version 2.0, January 2004 https://www.apache.org/licenses/ ``` Copyright (C) 2026 HighCapable