---

Playing with radare2 to dig into the CMU Bombs

We try to crack the cyber security bombs posted on CMU by using radare2.

• http://csapp.cs.cmu.edu/3e/labs.htm
• https://radare.gitbooks.io/radare2book/content/refcard/intro.html

1. Inspect the binary code in brief

   [18:45] CREST-MacBook-Pro-2: bomb $ rabin2 -I bomb
   arch     x86
   binsz    26406
   bintype  elf
   bits     64
   canary   true
   class    ELF64
   crypto   false
   endian   little
   havecode true
   intrp    /lib64/ld-linux-x86-64.so.2
   lang     c
   linenum  true
   lsyms    true
   machine  AMD x86-64 architecture
   maxopsz  16
   minopsz  1
   nx       true
   os       linux
   pcalign  0
   pic      false
   relocs   true
   relro    partial relro
   rpath    NONE
   static   false
   stripped false
   subsys   linux
   va       true
   [18:45] CREST-MacBook-Pro-2: bomb $ rabin2 -l bomb
   [Linked libraries]
   libc.so.6
   1 library
   [18:45] CREST-MacBook-Pro-2: bomb $
   

2. Load up the binary code in radare2

   [18:45] CREST-MacBook-Pro-2: bomb $ r2 bomb
   syntax error: error in error handling
   syntax error: error in error handling
   syntax error: error in error handling
    -- THIS IS NOT A BUG
   [0x00400c90]>
   

3. Cheat Sheet

   // Package Manager
   r2pm init
   r2pm update
   //Install www-m (material webui):
   r2pm -i www-m
   

   // General information about a file
   rabin2 -I <file>
   -l - dynamic libs
   -i - symbols
   

   // Load the binary code
   r2 <binary_code>
   aa - automatic analysis
   afl - look at symbols and functions
   s - seek to <symbol>
   pdf - print disassembly of a function (e.g. pdf @ main)
   V - enter visual mode, press V again to enter graph mode
   hjkl - navigation