r2dec

Converts asm to pseudo-C code.

Software Requirements

Requires radare2 version 2.6.9 or newer.

Install

Follow the following steps to install r2dec via r2pm

r2pm init
r2pm install r2dec

done

Usage

open with radare2 your file
analize the function you want to disassemble (af)
run the plugin via pdd
done.

Arguments

[0x00000c60]> pdd?
Usage: pdd [args] - core plugin for r2dec
 pdd   - decompile current function
 pdd?  - show this help
 pdda  - decompile current function with side assembly
 pddu  - install/upgrade r2dec via r2pm
 pddi  - generates the issue data
[0x00000c60]> pdd --help
r2dec [options]
       --help     | this help message
       --colors   | enables syntax colors
       --assembly | shows pseudo next to the assembly
       --offset   | shows pseudo next to the offset
       --casts    | shows all casts in the pseudo code
       --issue    | generates the json used for the test suite
       --debug    | do not catch exceptions
       --html     | outputs html data instead of text
       --xrefs    | shows all xrefs in the pseudo code

Radare2 Evaluable vars

You can use these in your .radare2rc file.

r2dec.casts         | if false, hides all casts in the pseudo code.
r2dec.asm           | if true, shows pseudo next to the assembly.
r2dec.offset        | if true, shows pseudo next to the offset.
r2dec.xrefs         | if true, shows all xrefs in the pseudo code.
r2dec.theme         | defines the color theme to be used on r2dec.
e scr.html          | outputs html data instead of text.
e scr.color         | enables syntax colors.

Report an Issue

open with radare2 your file
analize the function you want to disassemble (af)
give the data to the plugin via pddi or pdd --issue
insert the JSON returned by the previous command into the issue (you can also upload the output)
done.

Supported Arch

arm
avr
m68k (experimental)
mips
ppc
sparc
v850
wasm (partial)
x86 (intel)

Developing on r2dec

Read DEVELOPERS.md

Example

This example shows a possible dump of the plugin.

Source Code

#include <stdio.h>

int main(int argc, char const *argv[]) {
    int var = 0;
    while(var < 0x90) {
        if(var < 0x10) {
            var += 0x50;
        }
        var += 0x10;
    }
    return 0;
}

radare2 view

            ;-- main:
╭ (fcn) main 50
│   main ();
│           ; var int local_20h @ rbp-0x20
│           ; var int local_14h @ rbp-0x14
│           ; var int local_4h @ rbp-0x4
│              ; DATA XREF from 0x0000050d (entry0)
│           0x000005fa      55             push rbp
│           0x000005fb      4889e5         mov rbp, rsp
│           0x000005fe      897dec         mov dword [local_14h], edi
│           0x00000601      488975e0       mov qword [local_20h], rsi
│           0x00000605      c745fc000000.  mov dword [local_4h], 0
│       ╭─< 0x0000060c      eb0e           jmp 0x61c
│       │      ; JMP XREF from 0x00000623 (main)
│      ╭──> 0x0000060e      837dfc0f       cmp dword [local_4h], 0xf   ; [0xf:4]=0x3e000300
│     ╭───< 0x00000612      7f04           jg 0x618
│     │⁝│   0x00000614      8345fc50       add dword [local_4h], 0x50  ; 'P'
│     │⁝│      ; JMP XREF from 0x00000612 (main)
│     ╰───> 0x00000618      8345fc10       add dword [local_4h], 0x10
│      ⁝│      ; JMP XREF from 0x0000060c (main)
│      ⁝╰─> 0x0000061c      817dfc8f0000.  cmp dword [local_4h], 0x8f  ; [0x8f:4]=0x23800
│      ╰──< 0x00000623      7ee9           jle 0x60e
│           0x00000625      b800000000     mov eax, 0
│           0x0000062a      5d             pop rbp
╰           0x0000062b      c3             ret

r2dec pseudo-C code

#include <stdint.h>

int32_t main () {
    *((int32_t*) local_14h) = edi;
    *((int64_t*) local_20h) = rsi;
    *((int32_t*) local_4h) = 0;
    while (*((int32_t*) local_4h) > 0x8f) {
        if (*((int32_t*) local_4h) <= 0xf) {
            *((int32_t*) local_4h) += 0x50;
        }
        *((int32_t*) local_4h) += 0x10;
    }
    eax = 0;
    return eax;
}

codegrande / r2dec-js