Radare2, gcc and Docker toolkit

Let’s begin by creating a docker-compose.yml file in our project root.

version: "2"

services:
    build:
        image: gcc
        volumes:
            - ./src:/src
        command: "true"

    radare:
        image: remnux/radare2
        volumes:
            - ./src:/home/nonroot/workdir
        command: "true"

Create a directory called src in your project root and create a file sample.c inside that directory.

#include <stdio.h>

int main() {
    int a = 1;
    int b = 2;

    printf("Hello, world");

    return 0;
}

Build binary

$ docker-compose run --rm build gcc -o /src/sample /src/sample.c

Analyze binary

Launch the radare2 container.

$ docker-compose run --rm radare r2 sample

Use commands aa to analyze the binary and pdf@main to print-disassemble-function main function.

 -- Thank you for using radare2. Have a nice night!                                                                   
[0x004003f0]> aa                                                                                                      
[x] Analyze all flags starting with sym. and entry0 (aa)                                                              
[0x004003f0]> pdf@main                                                                                                
            ;-- main:                                                                                                 
/ (fcn) sym.main 40                                                                                                   
|           ; var int local_4h @ rbp-0x4                                                                              
|           ; var int local_8h @ rbp-0x8                                                                              
|           ; DATA XREF from 0x0040040d (entry0)                                                                      
|           0x004004e6      55             push rbp                                                                   
|           0x004004e7      4889e5         mov rbp, rsp                                                               
|           0x004004ea      4883ec10       sub rsp, 0x10                                                              
|           0x004004ee      c745fc010000.  mov dword [rbp - local_4h], 1                                              
|           0x004004f5      c745f8020000.  mov dword [rbp - local_8h], 2                                              
|           0x004004fc      bf94054000     mov edi, str.Hello__world   ; "Hello, world" @ 0x400594                    
|           0x00400501      b800000000     mov eax, 0                                                                 
|           0x00400506      e8b5feffff     call sym.imp.printf                                                        
|           0x0040050b      90             nop                                                                        
|           0x0040050c      c9             leave                                                                      
\           0x0040050d      c3             ret                                                                        
[0x004003f0]>