Reverse engineering is the process of understanding how a software or hardware system works without having its source code or design documents. Reverse engineering can be used for different goals, such as finding malware, discovering vulnerabilities, fixing software bugs, testing compatibility, and protecting intellectual property.
There are many tools for reverse engineers, but two of the most popular and powerful ones are Ghidra and IDA Pro. Ghidra is a free and open-source software reverse engineering suite made by the NSA and released to the public in 2019. IDA Pro is a commercial interactive disassembler and debugger made by Hex-Rays and widely used by security experts and professionals.
In this post, I will compare Ghidra and IDA Pro based on several criteria, such as features, functionality, usability, and performance. I will also mention some of the pros and cons of each tool and give some tips and resources for using them effectively.
Features:
Both Ghidra and IDA Pro have a lot of features for reverse engineering, such as:
• Support for many architectures and file formats, including x86, x64, ARM, MIPS, PowerPC, ELF, PE, Mach-O, and more.
• Graphical user interface (GUI) and command-line interface (CLI) for interacting with the tools and the target system.
• Disassembly and decompilation of binary code into assembly and high-level languages, such as C and C++.
• Analysis and annotation of code and data, such as functions, variables, types, structures, comments, cross-references, and more.
• Debugging and emulation capabilities for running and tracing the target system and changing its state.
• Scripting and plugin support for adding new features and customization to the tools.
However, there are also some differences and unique features between Ghidra and IDA Pro, such as:
• Ghidra is free and open-source, while IDA Pro is very expensive, especially when adding the decompiler licenses.
• Ghidra can load multiple binaries at the same time into a project, while IDA Pro has limited support for this. This means that you can follow code between an application and its libraries more easily in Ghidra.
• Ghidra has data flow analysis built into the disassembler, showing you where data can come from when you click a register or variable. IDA Pro has simple text highlighting to show other uses of that register. These features are slightly different implementations of the same concept and both have their uses.
• Ghidra has collaborative disassembly/decompiler projects built in by design, while IDA Pro needs plugins to do collaboration and the IDA database files are not designed to be shared.
• Ghidra has an undo button and it works. IDA Pro does not have an undo feature and it is super annoying.
• IDA Pro is more mature and has a lot of little features that have been added over the years that Ghidra cannot (yet) mirror. For example, IDA Pro has better support for patching binaries, renaming variables, and creating custom types.
• IDA Pro has a lot of open-source tools built around it, such as IDAPython, IDArling, IDASync, and more. Ghidra is still relatively new and does not have as many tools and plugins available yet.
• IDA Pro has better support for debugging and emulation, especially for Windows and Android systems. Ghidra does not have a native debugger and relies on external tools such as gdb or WinDBG. Ghidra also does not have a built-in emulator and needs plugins such as GhidraEmu or Unicorn to emulate code.
Functionality
Both Ghidra and IDA Pro are very functional and capable tools for reverse engineering, but they also have some limitations and drawbacks, such as:
• Ghidra and IDA Pro both have bugs and errors in their disassembly and decompilation engines, which can make the code and data incorrect or misleading. For example, Ghidra has some problems with the x86 instruction decoder, which can cause issues when analyzing Windows OS binaries. IDA Pro has some problems with analyzing large memory regions, which can cause crashes or slowdowns.
• Ghidra and IDA Pro both have steep learning curves and need a lot of time and effort to master. They also have different user interfaces and workflows, which can be confusing or frustrating for users who are used to one tool and switch to another.
• Ghidra and IDA Pro both have performance issues when dealing with very large (1GB+) firmware images or complex systems. They can use a lot of memory and CPU resources and take a long time to analyze and display the code and data.
• Ghidra and IDA Pro both have compatibility issues with some architectures and file formats, which can prevent them from opening or analyzing the target system correctly. For example, Ghidra does not support some exotic architectures such as SPARC or RISC-V, while IDA Pro does not support some modern file formats such as WebAssembly or Android App Bundle.
Usability:
Both Ghidra and IDA Pro have pros and cons when it comes to usability, such as:
• Ghidra has a more modern and user-friendly GUI than IDA Pro, which has a more old-fashioned and cluttered GUI. Ghidra also has better support for dark mode and high-DPI screens than IDA Pro.
• Ghidra has a more intuitive and consistent CLI than IDA Pro, which has a more cryptic and inconsistent CLI. Ghidra also has better documentation and help files than IDA Pro, which has more outdated and incomplete documentation.
• Ghidra has a more flexible and powerful scripting and plugin system than IDA Pro, which has a more rigid and limited scripting and plugin system. Ghidra supports multiple scripting languages, such as Java, Python, and JavaScript, while IDA Pro mainly supports Python and IDC. Ghidra also has a more open and accessible API than IDA Pro, which has a more closed and restricted API.
• Ghidra has a more active and supportive community than IDA Pro, which has a more passive and elitist community. Ghidra has more users and developers who are willing to share their knowledge and experience, while IDA Pro has more users and developers who are reluctant to share their secrets and tricks.
Performance:
Both Ghidra and IDA Pro have similar performance when it comes to reverse engineering, but they also have some differences, such as:
• Ghidra is faster and more efficient than IDA Pro when loading and analyzing multiple binaries at once, as it can use the multi-core and multi-threading features of the CPU. IDA Pro is slower and more cumbersome when loading and analyzing multiple binaries at once, as it can only use one core and one thread of the CPU.
• Ghidra is slower and more resource-intensive than IDA Pro when loading and analyzing very large or complex binaries, as it can use a lot of memory and CPU resources and take a long time to process the code and data. IDA Pro is faster and more resource-efficient when loading and analyzing very large or complex binaries, as it can optimize the memory and CPU usage and reduce the processing time.
• Ghidra is more stable and reliable than IDA Pro when debugging and emulating the target system, as it can handle exceptions and errors more smoothly and recover from crashes more easily. IDA Pro is more unstable and unreliable when debugging and emulating the target system, as it can cause exceptions and errors more often and fail to recover from crashes more often.
Conclusion
Ghidra and IDA Pro are both excellent tools for reverse engineering, but they also have their own strengths and weaknesses. There is no clear answer to which tool is better, as it depends on the user's preferences, needs, and goals. The best way to decide which tool to use is to try them both and see which one fits you better.