Let's start with a very simple function. It accepts a pointer to a structure and zeroes out its first three fields. While the function logic is obvious by just looking at the decompiler output, the assembly listing has too much noise and requires studying it.
Look, the decompiler output is longer! This is a rare case when the pseudocode is longer than the disassembly listing, but it is a for a good cause: to keep it readable. There are so many conditional instructions here, it is very easy to misunderstand the dependencies. For example, did you notice that the first MOVEQ may use the condition codes set by CMP? The subtle detail is that CMPNE may be skipped and the condition codes set by CMP may reach MOVEQs.
hex-rays arm decompiler
Since ARM instructions cannot have big immediate constants, sometimes they are loaded with two instructions. There are many 0xFA (250 decimal) constants in the disassembly listing, but all of them are shifted to the left by 2 before use. The decompiler saves you from these petty details.
In some case the disassembly listing can be misleading, especially with PIC (position independent code). While the address of a constant string is loaded into R12, the code does not care about it. It is just how variable addresses are calculated in PIC-code (it is .got-someoffset). Such calculations are very frequent in shared objects and unfortunately IDA cannot handle all of them. But the decompiler did a great job of tracing R12.
Currently the decompiler supports compiler generated code for the x86, x64, ARM32, ARM64, and PowerPC processors. We plan to port it to other platforms in the future. The programmatic API allows our customers to improve the decompiler output. Vulnerability search, software validation, coverage analysis are the directions that immediately come to mind.
9. How are subscriptions renewed? You will be able to renew your subscription directly through our web shop or, for multi-seats subscriptions, by contacting sales@hex-rays.com. In the future we will introduce automatic renewals.
11. What If I Want To Upgrade / Downgrade My Subscription? To upgrade please contact sales@hex-rays.com for more info. It is not possible to downgrade a subscription after it has been purchased or renewed. You will be able to change which bundle you have at the end of your subscription duration. Eg: If you have Teams Core from 1st August 2022 you can change to Teams Base on 1st August 2023
The decompiler comes in 9 different flavors:x86 decompiler (32-bit code)
x64 decompiler (64-bit code)
ARM decompiler (32-bit code)
ARM64 decompiler (64-bit code)
PowerPC decompiler (32-bit code)
PowerPC64 decompiler (64-bit code)
MIPS decompiler (O32 and N32 ABI)
MIPS64 decompiler (N64 ABI)
ARC Decompiler (32-bit code)
Currently the decompiler can handle compiler generated code. Manually crafted codemay be decompiled too but the results are usually worse than for compiler code.Support for other processors will eventually be added (no deadlinesare available, sorry).
Currently the decompiler supports 32bit compiled generated code for the x86 and ARM processors. We plan to port it to other platforms and add a programmatic API. This will allow our customers to implement their own analysis methods. Vulnerability search, software validation, coverage analysis are the directions that immediately come to mind.
Currently the decompiler can handle compiler generated code. Manually crafted code may be decompiled too but the results are usually worse than for compiler code. Support for other processors and 64-bit code will eventually be added (no deadlines are available, sorry).
The Interactive Disassembler (IDA) is a disassembler for computer software which generates assembly language source code from machine-executable code. It supports a variety of executable formats for different processors and operating systems. It also can be used as a debugger for Windows PE, Mac OS X Mach-O, and Linux ELF executables. A decompiler plug-in for programs compiled with a C/C++ compiler is available at extra cost. The latest full version of IDA Pro is commercial (version 8.2 as of December 2022), while a less capable version is available for download free of charge (version 8.1 as of October 2022[update]).[3]
Some old compilers, and compilers for real-time operating systems, typically place read-only and read-write data in the same segment. This leads to a situation wherein the decompiler shows variables instead of string literals where the latter are supposed to be.
It was tough and it required even more research than was planned but finallyit arrived. The 64-bit decompiler for x64 code is as simple to use as ourother decompilers, and fast as well. Below is very short disassembly listingand the decompiler's output for it:
IDA Teams is out! iOS 16 dyld shared cache support Outlined functions Golang 1.18 New decompiler: ARC Better firmware analysis thanks to the function finder plugin (patfind) FLAIR pattern generator (makepat) And much more!
IDA and the Hex-Rays decompiler are powerful tools, usable by engineers with any skill level; the higher the skills, the better the result.In order to get the best out of them, the people behind IDA regularly organize training sessions, to allow users to perfect their understanding of the concepts & methodology.Training comprises theoretical and practical sections, with hands-on exercises, given by experts. Different classes are provided upon the needs of students, from entry level to expert classes aimed at maximizing its capabilities!
With this version of IDA we publish the decompiler intermediate language: the microcode. We were planning to do it since very long time but the microcode was constantly evolving, we could not do it. After ten years of evolution it looks mature and ready to be published. We believe that it will permit our users to implement much more powerful and higher level analysis algorithms than before. In the future we plan to use the microcode in IDA too: if the decompiler is present, the analysis will be improved automatically.
Decompilation is the process of taking machine language instructions and translating them into a higher-level language representation. Decompilation is more typically used for analysis of computer viruses and malware, and, sometimes to recover lost source code or make a compatible product. One popular example of a decompiler is from Hex-Rays, who sells a very good decompiler for the i386 platform as a plug-in for its IDAPro dissassembler.
A decompiler isn't a silver bullet. Beyond the technical limits of our current decompiler, such as detection of for() loops or handling of functions with variable arguments, there are fundamental issues:
If the software to be audited is closed source and only executable binaries are available, some kind of c source can still be derived by using a decompiler. The low quality of decompiler output does not matter if the unused parts are removed automatically and then the new source code compiled. Distributing that new binary publicly may not be legal, but at least it can be used in home and in organization. 2ff7e9595c
Commentaires