# Bytecode Viewer Bytecode Viewer - a lightweight user-friendly Java/Android Bytecode Viewer, Decompiler & More. #### New Features * Patched [CVE-2022-21675](https://github.com/Konloch/bytecode-viewer/security/advisories/GHSA-3wq9-j4fc-4wmc) (Make sure to upgrade to v2.11.X) * Dark mode with multiple themes * Translated into over 30 languages including: Arabic, German, Japanese, Mandarin, Russian, Spanish * Plugin Writer - create and edit external plugins from within BCV * Fixed Java & Bytecode editing/compiling * Tabbed plugin console * Right-click menus on the resource and search panels * Javap disassembler * XAPK support * Updated nearly all dependencies (incl. decompilers like CFR, JD-GUI etc.) * Updated ASM library to version 9.1 * Added support to Java files compiled using JDK > 13 * Migrated to Maven #### Links * [BCV Discord](https://discord.gg/aexsYpfMEf) * [Website](https://bytecodeviewer.com) * [Source Code](https://github.com/konloch/bytecode-viewer) * [Bin/Archive](https://github.com/konloch/bytecode-viewer/releases) * [Java Docs](https://the.bytecode.club/docs/bytecode-viewer/) * [License (Copyleft)](https://raw.githubusercontent.com/Konloch/bytecode-viewer/master/LICENSE) * [Credits](https://github.com/Konloch/bytecode-viewer/blob/master/CREDITS.md) * [Contributing](https://github.com/Konloch/bytecode-viewer/blob/master/CONTRIBUTING.md) * [Report Bugs](https://github.com/Konloch/bytecode-viewer/issues) * [Discussion Forum](https://the.bytecode.club/forumdisplay.php?fid=69) #### Key Features * Simply drag and drop to decompile and search Java Jars & Android APKs * File format support for: Class, Jar, XAPK, APK, DEX, WAR, JSP, Image Resources, Text Resources & More * 6 Built-in Java decompilers: Krakatau, CFR, Procyon, FernFlower, JADX, JD-GUI * 3 Built-in Bytecode disassemblers, including 2 assemblers: Krakatau and Smali/BakSmali * APK/DEX Support from Dex2Jar and Enjarify * Built-in Java Compiler * Advanced static-search functionality * Customizable UI * Plugins + Script Engine Design * Malicious code scanning API * Translated Into over 30 Languages Including: Arabic, German, Japanese, Mandarin, Russian, Spanish) * Export functionality as Runnable Jar, Zip, APK, Decompile All As Zip, Etc. * And more! Give it a try for yourself! #### Command Line Input ``` -help Displays the help menu -clean Deletes the BCV directory -english Forces English language translations -list Displays the available decompilers -decompiler Selects the decompiler, procyon by default -i Selects the input file (Jar, Class, APK, ZIP, DEX all work automatically) -o Selects the output file (Java or Java-Bytecode) -t Must either be the fully qualified classname or "all" to decompile all as zip -nowait Doesn't wait for the user to read the CLI messages ``` ## What is Bytecode Viewer? Bytecode Viewer (BCV) is an Advanced Lightweight Java/Android Reverse Engineering Suite. Powered by several open source tools BCV is designed to aid in the reversing process. BCV comes with 6 decompilers, 3 disassemblers, 2 assemblers, 2 APK converters, advanced searching, debugging & more. It's written completely in Java, and it's open sourced. It's currently being maintained and developed by Konloch. ## Is there a demo? [![BCV Demo](https://img.youtube.com/vi/I5GT6PoTGOw/0.jpg)](https://www.youtube.com/watch?v=I5GT6PoTGOw) Please note this demo is from a very old version ## How do I install BCV? Download the latest version from https://github.com/konloch/bytecode-viewer/releases and run the Bytecode-Viewer-2.10.x.jar. You may need to execute it via command line ```java -jar Bytecode-Viewer-2.10.x.jar``` (replace the X with the current minor version) ## How can I use BCV? * Starting with a Jar, Zip, ClassFile or Android file (APK, DEX, XAPK, etc) drag it into BCV. It will start the decoding process automatically. * From here you can select the decompilers you would like to use by selecting the View Pane>View 1, View 2, View 3, etc. * The view panes are-used to display up to 3 decompilers side by side, you can also toggle edibility here. * Select the resource you would like to open by navigating using the resource list, BCV will do its best to display it (Decompiling, Disassembling, etc). * You can use plugins to help you search along with using the search pane in the left-hand bottom corner. ## How do the plugins work? There is also a plugin system that will allow you to interact with the loaded classfiles. You could for example write a String deobfuscator, a malicious code searcher, or anything else you can think of. You can either use one of the pre-written plugins, or write your own. The plugin system supports java and javascript scripting. Once a plugin is activated, it will execute the plugin with a ClassNode ArrayList of every single class loaded in BCV, this allows the user to handle it completely using ASM. ## Instructions to compile Just clone this repo and run ``mvn package``. It's that simple! ## Working on the source Open the Maven project (e.g. in IntelliJ, open the ``pom.xml`` as a project file). ## Java Heap Space Issues (java.lang.OutOfMemoryError) Start BCV with more RAM, e.g. `java -Xmx3G -jar BCV.jar` ## File Permission Issues (java.io.FileNotFoundException) Right click on the jar file, go to Properties, and select Unblock under Security at the bottom of the General tab. ## APK File Permission Issues (java.io.FileNotFoundException) Run BCV as administrator. #### Are you a Java Reverse Engineer? Do you want to learn? Join The Bytecode Club Today! - https://the.bytecode.club