Program for using IDA's .dif files to patch binaries

idapro_python_apply_dif_file_patch_to_idb.py

# from https://reverseengineering.stackexchange.com/a/11835/13408
# ported to python3 and IDA 8.0+ by Mahmoud Abdelkader


import idaapi
import ida_bytes
import ida_kernwin

def apply_dif_file(dif_file_name):
    print("Applying " + dif_file_name + " to database.")
    with open(dif_file_name, "r") as f:
        for line in f:
            if ":" not in line:
                continue
            splitted = line.split()
            off_in_file = splitted[0].replace(":", "")
            initial_byte = splitted[1]
            new_byte = splitted[2]

            # Converting offset to integer and then to the effective address
            offset = int(off_in_file, 16)
            ea = idaapi.get_fileregion_ea(offset)
            # Converting new byte from hex to integer
            new_byte_num = int(new_byte, 16)

            log = ("Patching 0x" + initial_byte + " to 0x" + new_byte +
                   " at 0x%X (ea 0x%X)..." % (offset, ea))

            current_byte = ida_bytes.get_db_byte(ea)
            if current_byte == new_byte_num:
                print(log + " Already patched")
                continue
            elif current_byte != int(initial_byte, 16):
                print(log + " Wrong byte 0x%X detected, aborting!!!" % current_byte)
                return

            print(log)
            ida_bytes.patch_byte(ea, new_byte_num)
    print("Done patching")

def apply_dif():
    dif_path = ida_kernwin.ask_file(0, "*.dif", "Select .dif file")
    if dif_path is None:
        print("No file selected")
        return

    apply_dif_file(dif_path)

apply_dif()