Padding and Patching

Ragg2, a tool in the radare2 suite, offers various options for padding and patching the generated bufferoutput. These options allow users to modify or extend the generated code in specific ways.

  • Appending Data:

    • Append hex bytes (-B)
    • Append file contents (-C)
    • Append 32-bit or 64-bit numbers (-n, -N)
    • Append strings (-S)

  • Patching Existing Data:

    • Patch dword or qword at a given offset (-d, -D)
    • Patch hex pairs at a given offset (-w)

  • Adding Padding:

    • Add padding after compilation (-p)
    • Options include NOP, trap instructions, or specific byte sequences

From ragg2 -h:

 -B [hexpairs]   append some hexpair bytes
 -C [file]       append contents of file
 -d [off:dword]  patch dword (4 bytes) at given offset
 -D [off:qword]  patch qword (8 bytes) at given offset
 -n [dword]      append 32bit number (4 bytes)
 -N [dword]      append 64bit number (8 bytes)
 -p [padding]    add padding after compilation (padding=n10s32)
                 ntas : begin nop, trap, 'a', sequence
                 NTAS : same as above, but at the end
 -S [string]     append a string
 -w [off:hex]    patch hexpairs at given offset