Binary Transformer

What is BT

BT is a static binary rewriting engine that can

• insert new instructions at arbitrary location
• modify existing instructions
• create new sections with precise control
• add entries to existing sections (e.g., .rel.text)
• ...

Example

This example demonstrates how to insert an "nop" instruction between every two instructions.

1. save the following code to nop.py ``` import sys from bintran import Elf32

def add_nop(elf):
    elf.insert(*[(i.address, '\x90') for i in elf.disasm()])
    return elf

if __name__ == '__main__':
    with open(sys.argv[1], 'rb') as obj:
        elf = Elf32(obj.read())
    elf = add_nop(elf)
    with open(sys.argv[1], 'wb') as obj:
        obj.write(str(elf))
```

2. prepare an object file test.o (maybe [helloworld] (http://en.wikipedia.org/wiki/List_of_Hello_world_program_examples#C)?)
3. remember the original layout: objdump -d test.o
4. try to insert "nop": python nop.py test.o
5. see the new layout: objdump -d test.o
6. check if such modification breaks the program by linking and running

What's More

test.py contains a few other examples such as replacing CALL instruction to semantically same instructions: PUSH + JMP. Take a look.