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idapatcher.py
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idapatcher.py
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#!/usr/bin/env python
# IDA Patcher is a plugin for Hex-Ray's IDA Pro disassembler designed to
# enhance IDA's ability to patch binary files and memory. The plugin is
# useful for tasks related to malware analysis, exploit development as well
# as bug patching. IDA Patcher blends into the standard IDA user interface
# through the addition of a subview and several menu items.
IDAPATCHER_VERSION = "2.1"
# IDA libraries
import ida_nalt
import idaapi
import idautils
import idc
import ida_ua
import ida_name
from ida_bytes import get_full_flags, is_code
from idaapi import Form, plugin_t
from ida_kernwin import Choose
# Python modules
import os
import shutil
import struct
import binascii
import pickle
import ctypes
# Other modules
from keystone import *
# Constants
BRANCH_INST = [
idaapi.NN_ja,
idaapi.NN_jae,
idaapi.NN_jb,
idaapi.NN_jbe,
idaapi.NN_jc,
idaapi.NN_jcxz,
idaapi.NN_je,
idaapi.NN_jecxz,
idaapi.NN_jg,
idaapi.NN_jge,
idaapi.NN_jl,
idaapi.NN_jle,
idaapi.NN_jmp,
idaapi.NN_jmpfi,
idaapi.NN_jmpni,
idaapi.NN_jmpshort,
idaapi.NN_jna,
idaapi.NN_jnae,
idaapi.NN_jnb,
idaapi.NN_jnbe,
idaapi.NN_jnc,
idaapi.NN_jne,
idaapi.NN_jng,
idaapi.NN_jnge,
idaapi.NN_jnl,
idaapi.NN_jnle,
idaapi.NN_jno,
idaapi.NN_jnp,
idaapi.NN_jns,
idaapi.NN_jnz,
idaapi.NN_jo,
idaapi.NN_jp,
idaapi.NN_jpe,
idaapi.NN_jpo,
idaapi.NN_jrcxz,
idaapi.NN_js,
idaapi.NN_jz,
idaapi.ARM_b,
idaapi.ARM_bl,
idaapi.ARM_blr,
idaapi.ARM_blx1,
idaapi.ARM_blx2,
idaapi.ARM_br,
idaapi.ARM_bx,
idaapi.ARM_bxj
]
PATCHABLE_TARGET = [
(KS_ARCH_ARM64, KS_MODE_LITTLE_ENDIAN),
(KS_ARCH_X86, KS_MODE_LITTLE_ENDIAN)
]
# for now it only support aarch64
# we have to differentiate aarch64 and arm
PATCHABLE_INST = [
idaapi.ARM_b,
idaapi.ARM_bl,
]
arch_lists = {
"X86 16-bit": (KS_ARCH_X86, KS_MODE_16), # X86 16-bit
"X86 32-bit": (KS_ARCH_X86, KS_MODE_32), # X86 32-bit
"X86 64-bit": (KS_ARCH_X86, KS_MODE_64), # X86 64-bit
"ARM": (KS_ARCH_ARM, KS_MODE_ARM), # ARM
"ARM Thumb": (KS_ARCH_ARM, KS_MODE_THUMB), # ARM Thumb
"ARM64 (ARMV8)": (KS_ARCH_ARM64, KS_MODE_LITTLE_ENDIAN) # ARM64
}
endian_lists = {
"Little Endian": KS_MODE_LITTLE_ENDIAN, # little endian
"Big Endian": KS_MODE_BIG_ENDIAN, # big endian
}
syntax_lists = {
"Intel": KS_OPT_SYNTAX_INTEL,
"Nasm": KS_OPT_SYNTAX_NASM,
"AT&T": KS_OPT_SYNTAX_ATT
}
#--------------------------------------------------------------------------
# Forms
#--------------------------------------------------------------------------
class PatchRestoreForm(Form):
"""
Form to aid in restoring patched bytes to their original values.
"""
def __init__(self, addr_str, fpos_str, patch_str, org_str):
Form.__init__(self,
r"""BUTTON YES* Restore
BUTTON CANCEL Cancel
Restore patch bytes
Address {strAddr}
File offset {strFpos}
<:{strOrg}>
""", {
'strAddr': Form.StringLabel(addr_str),
'strFpos': Form.StringLabel(fpos_str),
'strOrg': Form.MultiLineTextControl(text=org_str, flags = Form.MultiLineTextControl.TXTF_FIXEDFONT | Form.MultiLineTextControl.TXTF_READONLY),
})
self.Compile()
#--------------------------------------------------------------------------
class PatchEditForm(Form):
"""
Form to edit patched bytes.
"""
def __init__(self, addr_str, fpos_str, patch_str, org_str):
Form.__init__(self,
r"""Edit patch bytes
Address {strAddr}
File offset {strFpos}
<:{strPatch}>
""", {
'strAddr': Form.StringLabel(addr_str),
'strFpos': Form.StringLabel(fpos_str),
'strPatch': Form.MultiLineTextControl(text=patch_str, flags = Form.MultiLineTextControl.TXTF_FIXEDFONT),
})
self.Compile()
#--------------------------------------------------------------------------
class PatchApplyForm(Form):
"""
Form to prompt for target file, backup file, and the address
range to save patched bytes.
"""
def __init__(self, start_ea, end_ea, org_file, bkp_file):
Form.__init__(self,
r"""Apply patches to input file
{FormChangeCb}
<##Start EA :{intStartEA}>
<##End EA :{intEndEA}>
<##Input file :{orgFile}>
<##Backup file:{bkpFile}>
<##Create backup:{rBackup}>
<##Restore original bytes:{rRestore}>{cGroup1}>
""", {
'intStartEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=start_ea),
'intEndEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=end_ea),
'orgFile': Form.FileInput(swidth=50, open=True, value=org_file),
'bkpFile': Form.FileInput(swidth=50, open=True, value=bkp_file),
'cGroup1': Form.ChkGroupControl(("rBackup", "rRestore")),
'FormChangeCb': Form.FormChangeCb(self.OnFormChange),
})
self.Compile()
def OnFormChange(self, fid):
# Set initial state
if fid == -1:
self.EnableField(self.bkpFile, False)
# Toggle backup checkbox
elif fid == self.rBackup.id:
self.rBackup.checked = not self.rBackup.checked
self.EnableField(self.bkpFile, self.rBackup.checked)
# Toggle restore checkbox
elif fid == self.rRestore.id:
self.rRestore.checked = not self.rRestore.checked
return 1
#--------------------------------------------------------------------------
class PatchFillForm(Form):
"""
Form to fill a range of addresses with a specified byte value.
"""
def __init__(self, start_ea, end_ea, fill_value):
Form.__init__(self,
r"""BUTTON YES* Fill
Fill bytes
<##Start EA :{intStartEA}>
<##End EA :{intEndEA}>
<##Value :{intPatch}>
""", {
'intStartEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=start_ea),
'intEndEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=end_ea),
'intPatch': Form.NumericInput(swidth=40,tp=Form.FT_HEX,value=fill_value),
})
self.Compile()
#--------------------------------------------------------------------------
class PatchExportForm(Form):
"""
Form to fill a range of addresses with a specified byte value.
"""
def __init__(self):
Form.__init__(self,
r"""BUTTON YES* Export
Export patches
<Export path:{expPath}>
""", {
'expPath': Form.DirInput(swidth=50, value=os.path.dirname(ida_nalt.get_input_file_path()))
})
self.Compile()
#--------------------------------------------------------------------------
class PatchImportForm(Form):
"""
Form to fill a range of addresses with a specified byte value.
"""
def __init__(self):
self.chooser = EmbeddedChooser()
self.valid_patches = []
self.selected_idx = []
Form.__init__(self,
r"""BUTTON YES* Done
Import patches
<Loaded patches:{cChooser}>
<Import path:{impPath}>
<Import:{btnImport}><Patch select:{btnSelPatch}><Patch all:{btnPatch}>
<Log:{outputLog}>
""", {
'impPath': Form.FileInput(swidth=60, open=True, value=ida_nalt.get_input_file_path()+'.idapatch'),
'cChooser': Form.EmbeddedChooserControl(self.chooser, swidth=71),
'btnImport': Form.ButtonInput(self.OnImportClick),
'btnSelPatch': Form.ButtonInput(self.OnPatchClick),
'btnPatch': Form.ButtonInput(self.OnPatchClick, code=1),
'outputLog': Form.MultiLineTextControl(swidth=71, flags=Form.MultiLineTextControl.TXTF_READONLY)
})
self.Compile()
def OnImportClick(self, code):
imp_path = self.GetControlValue(self.impPath)
imp_data = []
with open(imp_path, 'rb') as imp_file:
imp_data = pickle.load(imp_file)
# workaround from
# https://stackoverflow.com/questions/10270970/python-how-do-i-capture-a-variable-declared-in-a-non-global-ancestral-outer-sco
output = ['']
patch_data = imp_data['patch']
branch_tag = imp_data['branch_tag']
# check correctness first
view_patches = []
for patch in zip(patch_data, branch_tag):
(var_name, offset, length, patch_val, org_val, comments), (patch_tag, orig_tag) = patch
def print_to_log(s, postfix=True):
if postfix:
name = idc.demangle_name(var_name, idc.get_inf_attr(idc.INF_SHORT_DN)) or var_name
log_text = '{} {}+0x{:04x}, {}byte(s)\n'.format(s, name, offset, length)
else:
log_text = s + '\n'
print(log_text[:-1])
output[0] += log_text
self.SetControlValue(self.outputLog, idaapi.textctrl_info_t(text=output[0], flags=Form.MultiLineTextControl.TXTF_READONLY))
self.RefreshField(self.outputLog)
if not var_name:
print_to_log('[Error] Unable to parse patch without symbol')
continue
var_addr = idc.get_name_ea_simple(var_name)
if var_addr == idc.BADADDR:
print_to_log('[Error] Unable to find symbol')
continue
patch_addr = var_addr + offset
if patch_tag:
if not check_symbol_addr(patch_tag):
if symbol_addr_fixup(patch_addr, patch_val, patch_tag):
print_to_log('[Notice] Auto fixed target symbol address')
for _, target_name, _ in patch_tag:
print_to_log(' => ' + target_name, postfix=False)
else:
print_to_log('[Warning] Dropping patch with different symbol address')
for _, target_name, _ in patch_tag:
print_to_log(' => ' + target_name, postfix=False)
continue
else:
# although symbol address is the same,
# the offset between instruction and function may change
print_to_log('[Notice] Branch target could be wrong')
seg = idc.get_segm_name(patch_addr)
name = idc.demangle_name(var_name, idc.get_inf_attr(idc.INF_SHORT_DN)) or var_name
name = "{}: {}".format(seg, name)
byte_str = idaapi.get_bytes(patch_addr, length)
org_str = struct.pack("B"*length, *org_val)
patch_str = struct.pack("B"*length, *patch_val)
if byte_str == org_str:
self.valid_patches.append((patch_addr, length, patch_val, comments))
view_patches.append([
name,
"{:04X}".format(offset),
str(length),
" ".join(map(lambda n: "{:02X}".format(n), patch_val)),
" ".join(map(lambda n: "{:02X}".format(n), org_val)),
comments
])
elif byte_str == patch_str:
print_to_log('[Notice] Already patched bytes')
elif orig_tag and rm_branch_cmp(byte_str, org_str, orig_tag) and check_branch_tag(patch_addr, orig_tag):
self.valid_patches.append((patch_addr, length, patch_val, comments))
view_patches.append([
name,
"{:04X}".format(offset),
str(length),
" ".join(map(lambda n: "{:02X}".format(n), patch_val)),
" ".join(map(lambda n: "{:02X}".format(n), org_val)),
comments
])
print_to_log('[Notice] Original bytes differ, still able to patch')
else:
print_to_log('[Warning] Dropping patch with different origin value')
self.chooser.SetItems(view_patches)
self.RefreshField(self.cChooser)
def OnPatchClick(self, code):
patches = []
if code == 1:
patches = self.valid_patches
view_patches = []
else:
idx = self.chooser.GetSelectedLine()
patches = [self.valid_patches[i] for i in idx]
view_patches = [self.chooser.items[i] for i in range(len(self.chooser.items)) if i not in idx]
for ea, length, patch_val, comments in patches:
idaapi.patch_bytes(ea, struct.pack("B"*length, *patch_val))
idc.set_cmt(to_var_base(ea), comments, 0)
self.chooser.SetItems(view_patches)
self.RefreshField(self.cChooser)
#--------------------------------------------------------------------------
class DataImportForm(Form):
"""
Form to import data of various types into selected area.
"""
def __init__(self, start_ea, end_ea):
syntax_keys = dict_to_ordered_list(syntax_lists)[0]
syntax_id = find_idx_by_value(syntax_lists, KS_OPT_SYNTAX_INTEL)
Form.__init__(self,
r"""BUTTON YES* Import
Import data
{FormChangeCb}
<Start EA :{intStartEA}>
<End EA :{intEndEA}>
Import type: Patching options:
<hex string:{rHex}><Trim to selection:{cSize}><NOP padding:{cPad}>{cGroup}>
<assembly:{rAsm}>
<string literal:{rString}>
<binary file:{rFile}>{rGroup}>
<Syntax\::{cSyntax}>
<:{strPatch}>
<Import BIN file:{impFile}>
""", {
'intStartEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=start_ea),
'intEndEA': Form.NumericInput(swidth=40,tp=Form.FT_ADDR,value=end_ea),
'cGroup': Form.ChkGroupControl(("cSize", "cPad")),
'rGroup': Form.RadGroupControl(("rHex", "rAsm", "rString", "rFile")),
'cSyntax': Form.DropdownListControl(
width=5,
swidth=5,
items = syntax_keys,
readonly = True,
selval = syntax_id
),
'strPatch': Form.MultiLineTextControl(swidth=80, flags=Form.MultiLineTextControl.TXTF_FIXEDFONT),
'impFile': Form.FileInput(swidth=50, open=True),
'FormChangeCb': Form.FormChangeCb(self.OnFormChange),
})
self.arch, _ = get_hardware_mode()
self.Compile()
def OnFormChange(self, fid):
# Form initialization
if fid == -1:
self.SetFocusedField(self.strPatch)
self.EnableField(self.strPatch, True)
self.EnableField(self.impFile, False)
self.EnableField(self.cSyntax, False)
if self.arch != KS_ARCH_X86:
self.ShowField(self.cSyntax, False)
self.ShowField(self.cPad, False)
else:
self.EnableField(self.cPad, True)
# Form OK pressed
elif fid == -2:
pass
# Form from text box
elif fid in (self.rHex.id, self.rAsm.id, self.rString.id):
if fid == self.rAsm.id:
self.EnableField(self.cSyntax, True)
else:
self.EnableField(self.cSyntax, False)
self.SetFocusedField(self.strPatch)
self.EnableField(self.strPatch, True)
self.EnableField(self.impFile, False)
# Form import from file
elif fid == self.rFile.id:
self.SetFocusedField(self.rFile)
self.EnableField(self.impFile, True)
self.EnableField(self.strPatch, False)
return 1
#--------------------------------------------------------------------------
class CommentEditForm(Form):
"""
Form to edit patched bytes.
"""
def __init__(self, comment):
Form.__init__(self,
r"""Edit comment
<:{strComment}>
""", { # how to set fixed width ?
'strComment': Form.MultiLineTextControl(width=280, text=comment, flags = Form.MultiLineTextControl.TXTF_FIXEDFONT)
})
self.Compile()
#--------------------------------------------------------------------------
# Helper functions
#--------------------------------------------------------------------------
def to_var_base(ea):
return idaapi.get_item_head(ea)
def prepare_patch_data(patches):
export_data = []
for (ea, fpos, len, patch_val, org_val, comments) in patches:
var_name = idc.get_func_name(ea) or get_name(to_var_base(ea))
base = idc.get_name_ea_simple(var_name)
offset = ea - base
if offset < 0:
print('[Error] Got negative offset:', ea, fpos, len, org_val, patch_val, comments)
return None
if var_name:
export_data.append([var_name, offset, len, patch_val, org_val, comments])
else:
print('[Warning] Cannot find variable name:', ea, fpos, len, org_val, patch_val, comments)
return export_data
def dict_to_ordered_list(dictionary):
l = sorted(list(dictionary.items()), key=lambda t: t[0], reverse=False)
keys = [i[0] for i in l]
values = [i[1] for i in l]
return (keys, values)
def get_value_by_idx(dictionary, idx, default=None):
(keys, values) = dict_to_ordered_list(dictionary)
try:
val = values[idx]
except IndexError:
val = default
return val
def find_idx_by_value(dictionary, value, default=None):
(keys, values) = dict_to_ordered_list(dictionary)
try:
idx = values.index(value)
except:
idx = default
return idx
def check_address(address):
try:
if idaapi.is_mapped(address):
return 1
else:
return -1
except:
# invalid type
return 0
def get_hardware_mode():
(arch, mode) = (None, None)
# heuristically detect hardware setup
info = idaapi.get_inf_structure()
try:
cpuname = info.procname.lower()
except:
cpuname = info.procName.lower()
try:
# since IDA7 beta 3 (170724) renamed inf.mf -> is_be()/set_be()
is_be = idaapi.cvar.inf.is_be()
except:
# older IDA versions
is_be = idaapi.cvar.inf.mf
# print("Keypatch BIG_ENDIAN = %s" %is_be)
if cpuname == "metapc":
arch = KS_ARCH_X86
if info.is_64bit():
mode = KS_MODE_64
elif info.is_32bit():
mode = KS_MODE_32
else:
mode = KS_MODE_16
elif cpuname.startswith("arm"):
# ARM or ARM64
if info.is_64bit():
arch = KS_ARCH_ARM64
if is_be:
mode = KS_MODE_BIG_ENDIAN
else:
mode = KS_MODE_LITTLE_ENDIAN
else:
arch = KS_ARCH_ARM
# either big-endian or little-endian
if is_be:
mode = KS_MODE_ARM | KS_MODE_BIG_ENDIAN
else:
mode = KS_MODE_ARM | KS_MODE_LITTLE_ENDIAN
elif cpuname.startswith("sparc"):
arch = KS_ARCH_SPARC
if info.is_64bit():
mode = KS_MODE_SPARC64
else:
mode = KS_MODE_SPARC32
if is_be:
mode |= KS_MODE_BIG_ENDIAN
else:
mode |= KS_MODE_LITTLE_ENDIAN
elif cpuname.startswith("ppc"):
arch = KS_ARCH_PPC
if info.is_64bit():
mode = KS_MODE_PPC64
else:
mode = KS_MODE_PPC32
if cpuname == "ppc":
# do not support Little Endian mode for PPC
mode += KS_MODE_BIG_ENDIAN
elif cpuname.startswith("mips"):
arch = KS_ARCH_MIPS
if info.is_64bit():
mode = KS_MODE_MIPS64
else:
mode = KS_MODE_MIPS32
if is_be:
mode |= KS_MODE_BIG_ENDIAN
else:
mode |= KS_MODE_LITTLE_ENDIAN
elif cpuname.startswith("systemz") or cpuname.startswith("s390x"):
arch = KS_ARCH_SYSTEMZ
mode = KS_MODE_BIG_ENDIAN
return (arch, mode)
# return (encoding, count), or (None, 0) on failure
def assemble(assembly, address, arch, mode, syntax=None):
# return assembly with arithmetic equation evaluated
def eval_operand(assembly, start, stop, prefix=''):
imm = assembly[start+1:stop]
try:
eval_imm = eval(imm)
if eval_imm > 0x80000000:
eval_imm = 0xffffffff - eval_imm
eval_imm += 1
eval_imm = -eval_imm
return assembly.replace(prefix + imm, prefix + hex(eval_imm))
except:
return assembly
# IDA uses different syntax from Keystone
# sometimes, we can convert code to be consumable by Keystone
def fix_ida_syntax(assembly):
# return True if this insn needs to be fixed
def check_arm_arm64_insn(arch, mnem):
if arch == KS_ARCH_ARM:
if mnem.startswith("ldr") or mnem.startswith("str"):
return True
return False
elif arch == KS_ARCH_ARM64:
if mnem.startswith("ldr") or mnem.startswith("str"):
return True
return mnem in ("stp")
return False
# return True if this insn needs to be fixed
def check_ppc_insn(mnem):
return mnem in ("stw")
# replace the right most string occurred
def rreplace(s, old, new):
li = s.rsplit(old, 1)
return new.join(li)
# convert some ARM pre-UAL assembly to UAL, so Keystone can handle it
# example: streqb --> strbeq
def fix_arm_ual(mnem, assembly):
# TODO: this is not an exhaustive list yet
if len(mnem) != 6:
return assembly
if (mnem[-1] in ('s', 'b', 'h', 'd')):
#print(">> 222", mnem[3:5])
if mnem[3:5] in ("cc", "eq", "ne", "hs", "lo", "mi", "pl", "vs", "vc", "hi", "ls", "ge", "lt", "gt", "le", "al"):
return assembly.replace(mnem, mnem[:3] + mnem[-1] + mnem[3:5], 1)
return assembly
if arch != KS_ARCH_X86:
assembly = assembly.lower()
else:
# Keystone does not support immediate 0bh, but only 0Bh
assembly = assembly.upper()
# however, 0X must be converted to 0x
# Keystone should fix this limitation in the future
assembly = assembly.replace("0X", " 0x")
_asm = assembly.partition(' ')
mnem = _asm[0]
if mnem == '':
return assembly
# for PPC, Keystone does not accept registers with 'r' prefix,
# but only the number behind. lets try to fix that here by
# removing the prefix 'r'.
if arch == KS_ARCH_PPC:
for n in range(32):
r = " r%u," %n
if r in assembly:
assembly = assembly.replace(r, " %u," %n)
for n in range(32):
r = "(r%u)" %n
if r in assembly:
assembly = assembly.replace(r, "(%u)" %n)
for n in range(32):
r = ", r%u" %n
if assembly.endswith(r):
assembly = rreplace(assembly, r, ", %u" %n)
if arch == KS_ARCH_X86:
if mnem == "RETN":
# replace retn with ret
return assembly.replace('RETN', 'RET', 1)
if 'OFFSET ' in assembly:
return assembly.replace('OFFSET ', ' ')
if mnem in ('CALL', 'JMP') or mnem.startswith('LOOP'):
# remove 'NEAR PTR'
if ' NEAR PTR ' in assembly:
return assembly.replace(' NEAR PTR ', ' ')
elif mnem[0] == 'J':
# JMP instruction
if ' SHORT ' in assembly:
# remove ' short '
return assembly.replace(' SHORT ', ' ')
elif arch in (KS_ARCH_ARM, KS_ARCH_ARM64, KS_ARCH_PPC):
# *** ARM
# LDR R1, [SP+rtld_fini],#4
# STR R2, [SP,#-4+rtld_fini]!
# STR R0, [SP,#fini]!
# STR R12, [SP,#4+var_8]!
# *** ARM64
# STP X29, X30, [SP,#-0x10+var_150]!
# STR W0, [X29,#0x150+var_8]
# LDR X0, [X0,#(qword_4D6678 - 0x4D6660)]
# TODO:
# ADRP X19, #interactive@PAGE
# *** PPC
# stw r5, 0x120+var_108(r1)
if arch == KS_ARCH_ARM and mode == KS_MODE_THUMB:
assembly = assembly.replace('movt.w', 'movt')
if arch == KS_ARCH_ARM:
#print(">> before UAL fix: ", assembly)
assembly = fix_arm_ual(mnem, assembly)
#print(">> after UAL fix: ", assembly)
if check_arm_arm64_insn(arch, mnem) or (("[" in assembly) and ("]" in assembly)):
bang = assembly.find('#')
bracket = assembly.find(']')
if bang != -1 and bracket != -1 and bang < bracket:
return eval_operand(assembly, bang, bracket, '#')
elif '+0x0]' in assembly:
return assembly.replace('+0x0]', ']')
elif check_ppc_insn(mnem):
start = assembly.find(', ')
stop = assembly.find('(')
if start != -1 and stop != -1 and start < stop:
return eval_operand(assembly, start, stop)
return assembly
def is_thumb(address):
return idc.get_sreg(address, 'T') == 1
if check_address(address) == 0:
return (None, 0)
if arch == KS_ARCH_ARM and is_thumb(address):
mode = KS_MODE_THUMB
try:
ks = Ks(arch, mode)
if arch == KS_ARCH_X86:
ks.syntax = syntax
# don't feed address param
encoding, count = ks.asm(fix_ida_syntax(assembly))
except KsError as e:
# keep the below code for debugging
# print("Keypatch Error: {0}".format(e))
# print("Original asm: {0}".format(assembly))
# print("Fixed up asm: {0}".format(fix_ida_syntax(assembly)))
encoding, count = None, 0
return (encoding, count)
def symbol_addr_fixup(patch_addr, patch_val, patch_tag):
arch, mode = get_hardware_mode()
if (arch, mode) not in PATCHABLE_TARGET:
return False
for offset, var_name, inst_exp in patch_tag:
symbol_addr = idc.get_name_ea_simple(var_name)
fixup_addr = patch_addr + offset
var_addr = inst_exp['xref']['address']
inst = inst_exp['itype']
# symbol doesn't exist
if var_addr == idaapi.BADADDR:
return False
# same address
if var_addr == symbol_addr:
continue
# cannot handle when offset < 0 but needs fixup
# (extend patch length)
if offset < 0:
return False
# not supported instruction
if inst not in PATCHABLE_INST:
return False
opcode = 0
if arch == KS_ARCH_ARM64:
diff = ctypes.c_uint32(symbol_addr - fixup_addr).value
if diff % 4 != 0:
print('[Error] Calculated address offset not aligned to 4 byte (aarch64)')
return False
if inst == idaapi.ARM_b:
if patch_val[offset + 3] & 0x14 == 0x14:
# 0 0 0 1 0 1 [imm26]
imm26 = (diff // 4) & 0x3ffffff
opcode = 0x14000000 | imm26
else:
# 0 1 0 1 0 1 0 0 [imm19] 0 [cond4]
imm19 = (diff // 4) & 0x7ffff
cond4 = patch_val[offset + 0] & 0xf
opcode = 0x54000000 | (imm19 << 5) | cond4
elif inst == idaapi.ARM_bl:
# 1 0 0 1 0 1 [imm26]
imm26 = (diff // 4) & 0x3ffffff
opcode = 0x94000000 | imm26
else:
print(f'[Error] Encountered unimplemented instruction: {inst}, file a issue or implement it yourself')
raise NotImplementedError
opcode = struct.pack('<I', opcode)
elif arch == KS_ARCH_X86:
raise NotImplementedError
for i in range(len(opcode)):
patch_val[offset + i] = opcode[i]
return True
def gen_branch_tag(start_ea, length):
branch_tags = []
inst_ea = to_var_base(start_ea)
end_ea = idc.next_head(start_ea + length)
while inst_ea < end_ea and is_code(get_full_flags(inst_ea)):
inst = ida_ua.insn_t()
ida_ua.decode_insn(inst, inst_ea)
# idaapi.is_indirect_jump_insn(inst) or idaapi.is_call_insn(inst) won't get idaapi.ARM_b instruction
if inst.itype in BRANCH_INST:
# can use XrefsFrom(ea, flags=ida_xref.XREF_FAR) as alternative to find xref address
for i in range(len(inst.ops)):
if idc.get_operand_type(inst.ea, i) in [idaapi.o_near, idaapi.o_far]:
# if it's a vaild near/far branch, func shouldn't return -1
branch_target = idc.get_operand_value(inst.ea, i)
var_name = get_name(branch_target)
offset = inst_ea - start_ea
# because inst comes from python C binding, it cannot be pickled
inst_exp = {
'Operands': [{
'reg': op.reg,
'type': op.type
} for op in inst.ops],
'itype': inst.itype,
'size': inst.size,
'xref': {
'idx': i,
'address': branch_target
}
}
# if it's in code section, ida pro will always generate a label for target address
# consider the patch here is not related to branch instructions
if not var_name:
continue
# ignore auto generated label
if var_name.startswith('loc_') or var_name.startswith('locret_') or var_name.startswith('sub_'):
pass
else:
branch_tags.append((offset, var_name, inst_exp))
break
inst_ea = idc.next_head(inst_ea)
return branch_tags
def unpatch_all(patch_data):
for patch in patch_data:
ea, _, length, _, org_val, _ = patch
idaapi.patch_bytes(ea, struct.pack("B"*length, *org_val))
def patch_all(patch_data):
for patch in patch_data:
ea, _, length, patch_val, _, _ = patch
idaapi.patch_bytes(ea, struct.pack("B"*length, *patch_val))
# to get original bytes, we have to first unpatch all the bytes
def gen_branch_tag_origin(patch_data):
branch_tag_list = []
unpatch_all(patch_data)
for patch in patch_data:
ea, _, length, _, _, _ = patch
branch_tag_list.append(gen_branch_tag(ea, length))
patch_all(patch_data)
return branch_tag_list
def gen_branch_tag_patched(patch_data):
branch_tag_list = []
for patch in patch_data:
ea, _, length, _, _, _ = patch
branch_tag_list.append(gen_branch_tag(ea, length))
return branch_tag_list
def prepare_branch_tag(patch_data):
patch_tag = gen_branch_tag_patched(patch_data)
orig_tag = gen_branch_tag_origin(patch_data)
return zip(patch_tag, orig_tag)
def rm_branch_cmp(byte_str, cmp_str, branch_tag):
adjust = 0
for (offset, var_name, inst_exp) in branch_tag:
start = (offset if offset >= 0 else 0) - adjust
end = offset + inst_exp['size'] - adjust
byte_str = byte_str[:start] + byte_str[end:]
cmp_str = cmp_str[:start] + cmp_str[end:]
adjust += end - start
return byte_str == cmp_str
def check_branch_tag(ea, branch_tag):
for (offset, var_name, inst_exp) in branch_tag:
inst = idautils.DecodeInstruction(ea + offset)
if all([op.reg == op_cmp['reg'] for (op, op_cmp) in zip(inst.ops, inst_exp['Operands'])]) and inst.itype == inst_exp['itype']:
branch_target = idc.get_operand_value(inst.ea, inst_exp['xref']['idx'])
if var_name != get_name(branch_target):
return False
else:
return False
return True
def check_symbol_addr(branch_tag):
for (offset, var_name, inst_exp) in branch_tag:
var_addr = idc.get_name_ea_simple(var_name)
if var_addr != inst_exp['xref']['address']:
return False
return True
def get_selection():
view = idaapi.get_current_viewer()
t0, t1 = idaapi.twinpos_t(), idaapi.twinpos_t()
start_ea, end_ea = None, None
if not idaapi.read_selection(view, t0, t1):
start_ea = idaapi.get_screen_ea()
end_ea = start_ea + 1
else:
start_ea, end_ea = t0.place(view).ea, t1.place(view).ea
return start_ea, end_ea
def get_name(ea):
return idc.get_name(ea, ida_name.GN_VISIBLE)
#--------------------------------------------------------------------------
# Chooser
#--------------------------------------------------------------------------
class EmbeddedChooser(Choose):
"""
Chooser class embedded in import form.
"""
def __init__(self):
Choose.__init__(self,
"Import",
[ ["Name", 18 | Choose.CHCOL_PLAIN],
["Offset", 5 | Choose.CHCOL_HEX],
["Size", 4 | Choose.CHCOL_DEC],
["Patched", 10 | Choose.CHCOL_HEX],
["Original", 10 | Choose.CHCOL_HEX],