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keypatch.py
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keypatch.py
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# -*- coding: utf-8 -*-
# Keypatch IDA Plugin, powered by Keystone Engine (http://www.keystone-engine.org).
# By Nguyen Anh Quynh & Thanh Nguyen, 2016.
# Keypatch is released under the GPL v2. See COPYING for more information.
# Find docs & latest version at http://keystone-engine.org/keypatch
# This IDA plugin includes 3 tools inside: Patcher, Fill Range & Search.
# Access to these tools via menu "Edit | Keypatch", or via right-click popup menu "Keypatch".
# Hotkey Ctrl-Alt-K opens either Patcher or "Fill Range" window, depending on context.
# - If there is no code selection, hotkey opens Patcher dialog
# - If a range of code is selected, hotkey opens "Fill Range" dialog
# To revert (undo) the last patching, choose menu "Edit | Keypatch | Undo last patching".
# To check for update version, choose menu "Edit | Keypatch | Check for update".
import os
import re
import json
from keystone import *
import idc
import idaapi
from idc import GetOpType, GetOpnd, ItemEnd
# bleeding-edge version
# on a new release, this should be sync with VERSION_STABLE file
VERSION = "2.2"
MAX_INSTRUCTION_STRLEN = 64
MAX_ENCODING_LEN = 40
MAX_ADDRESS_LEN = 40
ENCODING_ERR_OUTPUT = "..."
KP_GITHUB_VERSION = "https://raw.githubusercontent.com/keystone-engine/keypatch/master/VERSION_STABLE"
KP_HOMEPAGE = "http://keystone-engine.org/keypatch"
X86_NOP = "\x90"
# Configuration file
KP_CFGFILE = os.path.join(idaapi.get_user_idadir(), "keypatch.cfg")
# save all the info on patching
patch_info = []
def to_hexstr(buf, sep=' '):
return sep.join("{0:02x}".format(ord(c)) for c in buf).upper()
# return a normalized code, or None if input is invalid
def convert_hexstr(code):
# normalize code
code = code.lower()
code = code.replace(' ', '') # remove space
code = code.replace('h', '') # remove trailing 'h' in 90h
code = code.replace('0x', '') # remove 0x
code = code.replace('\\x', '') # remove \x
code = code.replace(',', '') # remove ,
code = code.replace(';', '') # remove ;
code = code.replace('"', '') # remove "
code = code.replace("'", '') # remove '
code = code.replace("+", '') # remove +
# single-digit hexcode?
if len(code) == 1 and ((code >= '0' and code <= '9') or (code >= 'a' and code <= 'f')):
# stick 0 in front (so 'a' --> '0a')
code = '0' + code
# odd-length is invalid
if len(code) % 2 != 0:
return None
try:
hex_data = code.decode('hex')
# we want a list of int
return [ord(i) for i in hex_data]
except:
# invalid hex
return None
# download a file from @url, then return (result, file-content)
# return (0, content) on success, or ({1|2}, None) on download failure
def url_download(url):
from urllib2 import Request, urlopen, URLError, HTTPError
# create the url and the request
req = Request(url)
# Open the url
try:
# download this URL
f = urlopen(req)
content = f.read()
return (0, content)
# handle errors
except HTTPError, e:
# print "HTTP Error:", e.code , url
# fail to download this file
return (1, None)
except URLError, e:
# print "URL Error:", e.reason , url
# fail to download this file
return (1, None)
except Exception as e:
# fail to save the downloaded file
# print("Error:", e)
return (2, None)
## Main Keypatch class
class Keypatch_Asm:
# supported architectures
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
"Hexagon": (KS_ARCH_HEXAGON, KS_MODE_BIG_ENDIAN), # Hexagon
"Mips32": (KS_ARCH_MIPS, KS_MODE_MIPS32), # Mips32
"Mips64": (KS_ARCH_MIPS, KS_MODE_MIPS64), # Mips64
"PowerPC 32": (KS_ARCH_PPC, KS_MODE_PPC32), # PPC32
"PowerPC 64": (KS_ARCH_PPC, KS_MODE_PPC64), # PPC64
"Sparc 32": (KS_ARCH_SPARC, KS_MODE_SPARC32), # Sparc32
"Sparc 64": (KS_ARCH_SPARC, KS_MODE_SPARC64), # Sparc64
"SystemZ": (KS_ARCH_SYSTEMZ, KS_MODE_BIG_ENDIAN), # SystemZ
}
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
}
def __init__(self, arch=None, mode=None):
# update current arch and mode
self.update_hardware_mode()
# override arch & mode if provided
if arch is not None:
self.arch = arch
if mode is not None:
self.mode = mode
# IDA uses Intel syntax by default
self.syntax = KS_OPT_SYNTAX_INTEL
# return Keystone arch & mode (with endianess included)
@staticmethod
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)
def update_hardware_mode(self):
(self.arch, self.mode) = self.get_hardware_mode()
# normalize assembly code
# remove comment at the end of assembly code
@staticmethod
def asm_normalize(text):
text = ' '.join(text.split())
if text.rfind(';') != -1:
return text[:text.rfind(';')].strip()
return text.strip()
@staticmethod
# check if input address is valid
# return
# -1 invalid address at target binary
# 0 type mismatch of input address
# 1 valid address at target binary
def check_address(address):
try:
if idaapi.isEnabled(address):
return 1
else:
return -1
except:
# invalid type
return 0
### resolve IDA names from input asm code
# todo: a better syntax parser for all archs
def ida_resolve(self, assembly, address=idc.BADADDR):
def _resolve(_op, ignore_kw=True):
names = re.findall(r"\b[a-z0-9_:\.]+\b", _op, re.I)
# try to resolve all names
for name in names:
# ignore known keywords
if ignore_kw and name in ('byte', 'near', 'short', 'word', 'dword', 'ptr', 'offset'):
continue
sym = name
# split segment reg
parts = name.partition(':')
if parts[2] != '':
sym = parts[2]
(t, v) = idaapi.get_name_value(address, sym)
# skip if name doesn't exist or segment / segment registers
if t in (idaapi.NT_SEG, idaapi.NT_NONE):
continue
_op = _op.replace(sym, '0x{0:X}'.format(v))
return _op
if self.check_address(address) == 0:
print("Keypatch: WARNING: invalid input address {0}".format(address))
return assembly
# for now, we only support IDA name resolve for X86, ARM, ARM64, MIPS, PPC, SPARC
if not (self.arch in (KS_ARCH_X86, KS_ARCH_ARM, KS_ARCH_ARM64, KS_ARCH_MIPS, KS_ARCH_PPC, KS_ARCH_SPARC)):
return assembly
_asm = assembly.partition(' ')
mnem = _asm[0]
opers = _asm[2].split(',')
for idx, op in enumerate(opers):
_op = list(op.partition('['))
ignore_kw = True
if _op[1] == '':
_op[2] = _op[0]
_op[0] = ''
else:
_op[0] = _resolve(_op[0], ignore_kw=True)
ignore_kw = False
_op[2] = _resolve(_op[2], ignore_kw=ignore_kw)
opers[idx] = ''.join(_op)
asm = "{0} {1}".format(mnem, ','.join(opers))
return asm
# return bytes of instruction or data
# return None on failure
def ida_get_item(self, address, hex_output=False):
if self.check_address(address) != 1:
# not a valid address
return (None, 0)
# return None if address is in the middle of instruction / data
if address != idc.ItemHead(address):
return (None, 0)
len = idc.ItemSize(address)
item = idaapi.get_many_bytes(address, len)
if item is None:
return (None, 0)
if hex_output:
item = to_hexstr(item)
return (item, len)
@staticmethod
def get_op_dtype_name(op_idx):
dtyp_lists = {
idaapi.dt_byte: 'byte', # 8 bit
idaapi.dt_word: 'word', # 16 bit
idaapi.dt_dword: 'dword', # 32 bit
idaapi.dt_float: 'dword', # 4 byte
idaapi.dt_double: 'dword', # 8 byte
#idaapi.dt_tbyte = 5 # variable size (ph.tbyte_size)
#idaapi.dt_packreal = 6 # packed real format for mc68040
idaapi.dt_qword: 'qword', # 64 bit
idaapi.dt_byte16: 'xmmword',# 128 bit
#idaapi.dt_code = 9 # ptr to code (not used?)
#idaapi.dt_void = 10 # none
#idaapi.dt_fword = 11 # 48 bit
#idaapi.dt_bitfild = 12 # bit field (mc680x0)
#idaapi.dt_string = 13 # pointer to asciiz string
#idaapi.dt_unicode = 14 # pointer to unicode string
#idaapi.dt_3byte = 15 # 3-byte data
#idaapi.dt_ldbl = 16 # long double (which may be different from tbyte)
idaapi.dt_byte32: 'ymmword',# 256 bit
}
dtype = idaapi.cmd.Operands[op_idx].dtyp
dtyp_size = idaapi.get_dtyp_size(dtype)
if dtype == idaapi.dt_tbyte:
if dtyp_size == 10:
return 'xword'
dtyp_name = dtyp_lists.get(idaapi.cmd.Operands[op_idx].dtyp, None)
return dtyp_name
# return asm instructions from start to end
def ida_get_disasm_range(self, start, end):
codes = []
while start < end:
asm = self.asm_normalize(idc.GetDisasm(start))
if asm == None:
asm = ''
codes.append(asm)
start = start + idc.ItemSize(start)
return codes
# get disasm from IDA
# return '' on invalid address
def ida_get_disasm(self, address, fixup=False):
def GetMnem(asm):
sp = asm.find(' ')
if sp == -1:
return asm
return asm[:sp]
if self.check_address(address) != 1:
# not a valid address
return ''
# return if address is in the middle of instruction / data
if address != idc.ItemHead(address):
return ''
asm = self.asm_normalize(idc.GetDisasm(address))
# for now, only support IDA syntax fixup for Intel CPU
if not fixup or self.arch != KS_ARCH_X86:
return asm
# KS_ARCH_X86 mode
# rebuild disasm code from IDA
i = 0
mnem = GetMnem(asm)
if mnem == '' or mnem in ('rep', 'repne', 'repe'):
return asm
opers = []
while GetOpType(address, i) > 0 and i < 6:
t = GetOpType(address, i)
o = GetOpnd(address, i)
if t in (idc.o_mem, idc.o_displ):
parts = list(o.partition(':'))
if parts[2] == '':
parts[2] = parts[0]
parts[0] = ''
if '[' not in parts[2]:
parts[2] = '[{0}]'.format(parts[2])
o = ''.join(parts)
if 'ptr ' not in o:
dtyp_name = self.get_op_dtype_name(i)
if dtyp_name != None:
o = "{0} ptr {1}".format(dtyp_name, o)
opers.append(o)
i += 1
asm = mnem
for o in opers:
if o != '':
asm = "{0} {1},".format(asm, o)
asm = asm.strip(',')
return asm
# assemble code with Keystone
# return (encoding, count), or (None, 0) on failure
def assemble(self, assembly, address, arch=None, mode=None, 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 self.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 self.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 self.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 self.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 self.arch == KS_ARCH_ARM and mode == KS_MODE_THUMB:
assembly = assembly.replace('movt.w', 'movt')
if self.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(self.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.GetReg(address, 'T') == 1
if self.check_address(address) == 0:
return (None, 0)
# use default syntax, arch and mode if not provided
if syntax is None:
syntax = self.syntax
if arch is None:
arch = self.arch
if mode is None:
mode = self.mode
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
encoding, count = ks.asm(fix_ida_syntax(assembly), address)
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)
# patch at address, return the number of written bytes & original data
# this process can fail in some cases
@staticmethod
def patch_raw(address, patch_data, len):
ea = address
orig_data = ''
while ea < (address + len):
if not idc.hasValue(idc.GetFlags(ea)):
print("Keypatch: FAILED to read data at 0x{0:X}".format(ea))
break
orig_byte = idc.Byte(ea)
orig_data += chr(orig_byte)
patch_byte = ord(patch_data[ea - address])
if patch_byte != orig_byte:
# patch one byte
if idaapi.patch_byte(ea, patch_byte) != 1:
print("Keypatch: FAILED to patch byte at 0x{0:X} [0x{1:X}]".format(ea, patch_byte))
break
ea += 1
return (ea - address, orig_data)
# patch at address, return the number of written bytes & original data
# on patch failure, we revert to the original code, then return (None, None)
def patch(self, address, patch_data, len):
# save original function end to fix IDA re-analyze issue after patching
orig_func_end = idc.GetFunctionAttr(address, idc.FUNCATTR_END)
(patched_len, orig_data) = self.patch_raw(address, patch_data, len)
if len != patched_len:
# patch failure
if patched_len > 0:
# revert the changes
(rlen, _) = self.patch_raw(address, orig_data, patched_len)
if rlen == patched_len:
print("Keypatch: successfully reverted changes of {0:d} byte(s) at 0x{1:X} [{2}]".format(
patched_len, address, to_hexstr(orig_data)))
else:
print("Keypatch: FAILED to revert changes of {0:d} byte(s) at 0x{1:X} [{2}]".format(
patched_len, address, to_hexstr(orig_data)))
return (None, None)
# ask IDA to re-analyze the patched area
if orig_func_end == idc.BADADDR:
# only analyze patched bytes, otherwise it would take a lot of time to re-analyze the whole binary
idaapi.analyze_area(address, address + patched_len + 1)
else:
idaapi.analyze_area(address, orig_func_end)
# try to fix IDA function re-analyze issue after patching
idaapi.func_setend(address, orig_func_end)
return (patched_len, orig_data)
# return number of bytes patched
# return
# 0 Invalid assembly
# -1 PatchByte failure
# -2 Can't read original data
# -3 Invalid address
def patch_code(self, address, assembly, syntax, padding, save_origcode, orig_asm=None, patch_data=None, patch_comment=None, undo=False):
global patch_info
if self.check_address(address) != 1:
# not a valid address
return -3
orig_comment = idc.Comment(address)
if orig_comment is None:
orig_comment = ''
nop_comment = ""
padding_len = 0
if not undo:
# we are patching via Patcher
(orig_encoding, orig_len) = self.ida_get_item(address)
if (orig_encoding, orig_len) == (None, 0):
return -2
(encoding, count) = self.assemble(assembly, address, syntax=syntax)
if encoding is None:
return 0
patch_len = len(encoding)
patch_data = ''.join(chr(c) for c in encoding)
if patch_data == orig_encoding:
#print("Keypatch: no need to patch, same encoding data [{0}] at 0x{1:X}".format(to_hexstr(orig_encoding), address))
return orig_len
# for now, only support NOP padding on Intel CPU
if padding and self.arch == KS_ARCH_X86:
if patch_len < orig_len:
padding_len = orig_len - patch_len
patch_len = orig_len
patch_data = patch_data.ljust(patch_len, X86_NOP)
elif patch_len > orig_len:
patch_end = address + patch_len - 1
ins_end = ItemEnd(patch_end)
padding_len = ins_end - patch_end - 1
if padding_len > 0:
patch_len = ins_end - address
patch_data = patch_data.ljust(patch_len, X86_NOP)
if padding_len > 0:
nop_comment = "\nKeypatch padded NOP to next boundary: {0} bytes".format(padding_len)
orig_asm = self.ida_get_disasm_range(address, address + patch_len)
else:
# we are reverting the change via "Undo" menu
patch_len = len(patch_data)
(plen, p_orig_data) = self.patch(address, patch_data, patch_len)
if plen is None:
# failed to patch
return -1
if not undo: # we are patching
new_patch_comment = None
if save_origcode is True:
# append original instruction to comments
if orig_comment == '':
new_patch_comment = "Keypatch modified this from:\n {0}{1}".format('\n '.join(orig_asm), nop_comment)
else:
new_patch_comment = "\nKeypatch modified this from:\n {0}{1}".format('\n '.join(orig_asm), nop_comment)
new_comment = "{0}{1}".format(orig_comment, new_patch_comment)
idc.MakeComm(address, new_comment)
if padding_len == 0:
print("Keypatch: successfully patched {0:d} byte(s) at 0x{1:X} from [{2}] to [{3}]".format(plen,
address, to_hexstr(p_orig_data), to_hexstr(patch_data)))
else:
print("Keypatch: successfully patched {0:d} byte(s) at 0x{1:X} from [{2}] to [{3}], with {4} byte(s) NOP padded".format(plen,
address, to_hexstr(p_orig_data), to_hexstr(patch_data), padding_len))
# save this patching for future "undo"
patch_info.append((address, assembly, p_orig_data, new_patch_comment))
else: # we are reverting
if patch_comment:
# clean previous IDA comment by replacing it with ''
new_comment = orig_comment.replace(patch_comment, '')
idc.MakeComm(address, new_comment)
print("Keypatch: successfully reverted {0:d} byte(s) at 0x{1:X} from [{2}] to [{3}]".format(plen,
address, to_hexstr(p_orig_data), to_hexstr(patch_data)))
return plen
# fill a range of code [addr_begin, addr_end].
# return the length of patched area
# on failure, return 0 = wrong input, -1 = failed to patch
def fill_code(self, addr_begin, addr_end, assembly, syntax, padding, save_origcode, orig_asm=None):
# treat input as assembly code first
(encoding, _) = self.assemble(assembly, addr_begin, syntax=syntax)
if encoding is None:
# input might be a hexcode string. try to convert it to raw bytes
encoding = convert_hexstr(assembly)
if encoding is None:
# invalid input: this is neither assembly nor hexcode string
return 0
# save original assembly code before overwritting them
orig_asm = self.ida_get_disasm_range(addr_begin, addr_end)
# save original comment at addr_begin
# TODO: save comments in this range, but how to interleave them?
orig_comment = idc.Comment(addr_begin)
if orig_comment is None:
orig_comment = ''
patch_data = ""
assembly_new = []
size = addr_end - addr_begin
# calculate filling data
encode_chr = ''.join(chr(c) for c in encoding)
while True:
if len(patch_data) + len(encode_chr) <= size:
patch_data = patch_data + encode_chr
assembly_new += [assembly.strip()]
else:
break
# for now, only support NOP padding on Intel CPU
if padding and self.arch == KS_ARCH_X86:
for i in range(size -len(patch_data)):
assembly_new += ["nop"]
patch_data = patch_data.ljust(size, X86_NOP)
(plen, p_orig_data) = self.patch(addr_begin, patch_data, len(patch_data))
if plen is None:
# failed to patch
return -1
new_patch_comment = ''
# append original instruction to comments
if save_origcode is True:
if orig_comment == '':
new_patch_comment = "Keypatch filled range [0x{0:X}:0x{1:X}] ({2} bytes), replaced:\n {3}".format(addr_begin, addr_end - 1, addr_end - addr_begin, '\n '.join(orig_asm))
else:
new_patch_comment = "\nKeypatch filled range [0x{0:X}:0x{1:X}] ({2} bytes), replaced:\n {3}".format(addr_begin, addr_end - 1, addr_end - addr_begin, '\n '.join(orig_asm))
new_comment = "{0}{1}".format(orig_comment, new_patch_comment)
idc.MakeComm(addr_begin, new_comment)
print("Keypatch: successfully filled range [0x{0:X}:0x{1:X}] ({2} bytes) with \"{3}\", replaced \"{4}\"".format(
addr_begin, addr_end - 1, addr_end - addr_begin, assembly, '; '.join(orig_asm)))
# save this modification for future "undo"
patch_info.append((addr_begin, '\n '.join(assembly_new), p_orig_data, new_patch_comment))
return plen
### Form helper functions
@staticmethod
def dict_to_ordered_list(dictionary):
list = sorted(dictionary.items(), key=lambda t: t[0], reverse=False)
keys = [i[0] for i in list]
values = [i[1] for i in list]
return (keys, values)
def get_value_by_idx(self, dictionary, idx, default=None):
(keys, values) = self.dict_to_ordered_list(dictionary)
try:
val = values[idx]
except IndexError:
val = default
return val
def find_idx_by_value(self, dictionary, value, default=None):
(keys, values) = self.dict_to_ordered_list(dictionary)
try:
idx = values.index(value)
except:
idx = default
return idx
def get_arch_by_idx(self, idx):
return self.get_value_by_idx(self.arch_lists, idx)
def find_arch_idx(self, arch, mode):
return self.find_idx_by_value(self.arch_lists, (arch, mode))
def get_syntax_by_idx(self, idx):
return self.get_value_by_idx(self.syntax_lists, idx, self.syntax)
def find_syntax_idx(self, syntax):
return self.find_idx_by_value(self.syntax_lists, syntax)
### /Form helper functions
# Common ancestor form to be derived by Patcher, FillRange & Search
class Keypatch_Form(idaapi.Form):
# prepare for form initializing
def setup(self, kp_asm, address, assembly=None):
self.kp_asm = kp_asm
self.address = address
# update ordered list of arch and syntax
self.syntax_keys = self.kp_asm.dict_to_ordered_list(self.kp_asm.syntax_lists)[0]
self.arch_keys = self.kp_asm.dict_to_ordered_list(self.kp_asm.arch_lists)[0]
# update current arch & mode
self.kp_asm.update_hardware_mode()
# find right value for c_arch & c_endian controls
mode = self.kp_asm.mode
self.endian_id = 0 # little endian
if self.kp_asm.mode & KS_MODE_BIG_ENDIAN:
self.endian_id = 1 # big endian
mode = self.kp_asm.mode - KS_MODE_BIG_ENDIAN
self.arch_id = self.kp_asm.find_arch_idx(self.kp_asm.arch, mode)
self.syntax_id = 0 # to make non-X86 arch happy
if self.kp_asm.arch == KS_ARCH_X86:
self.syntax_id = self.kp_asm.find_syntax_idx(self.kp_asm.syntax)
# get original instruction and bytes
self.orig_asm = kp_asm.ida_get_disasm(address)
(self.orig_encoding, self.orig_len) = kp_asm.ida_get_item(address, hex_output=True)
if self.orig_encoding is None:
self.orig_encoding = ''
if assembly is None:
self.asm = self.kp_asm.ida_get_disasm(self.address, fixup=True)
else:
self.asm = assembly
# update Encoding control
# return True on success, False on failure
def _update_encoding(self, arch, mode):
try:
syntax = None
if arch == KS_ARCH_X86:
syntax_id = self.GetControlValue(self.c_syntax)
syntax = self.kp_asm.get_syntax_by_idx(syntax_id)
address = self.GetControlValue(self.c_addr)
try:
idaapi.isEnabled(address)
except:
# invalid address value
address = 0
assembly = self.GetControlValue(self.c_assembly)
raw_assembly = self.kp_asm.ida_resolve(assembly, address)
self.SetControlValue(self.c_raw_assembly, raw_assembly)
(encoding, count) = self.kp_asm.assemble(raw_assembly, address, arch=arch,
mode=mode, syntax=syntax)
if encoding is None:
self.SetControlValue(self.c_encoding, ENCODING_ERR_OUTPUT)
self.SetControlValue(self.c_encoding_len, 0)
return False
else:
text = ""
for byte in encoding:
text += "%02X " % byte
text.strip()
if text == "":
# error?
self.SetControlValue(self.c_encoding, ENCODING_ERR_OUTPUT)
return False
else:
self.SetControlValue(self.c_encoding, text.strip())
self.SetControlValue(self.c_encoding_len, len(encoding))
return True
except Exception,e:
print (str(e))
import traceback
traceback.print_exc()
self.SetControlValue(self.c_encoding, ENCODING_ERR_OUTPUT)
return False
# callback to be executed when any form control changed
def OnFormChange(self, fid):
return 1
# update Patcher & Fillrange controls
def update_patchform(self, fid):
self.EnableField(self.c_endian, False)
self.EnableField(self.c_addr, False)
(arch, mode) = (self.kp_asm.arch, self.kp_asm.mode)
# assembly is focused
self.SetFocusedField(self.c_assembly)
if arch == KS_ARCH_X86:
# do not show Endian control
self.ShowField(self.c_endian, False)
# allow to choose Syntax
self.ShowField(self.c_syntax, True)
self.ShowField(self.c_opt_padding, True)
else: # do not show Syntax control for non-X86 mode
self.ShowField(self.c_syntax, False)
# for now, we do not support padding for non-X86 archs
self.ShowField(self.c_opt_padding, False)
#self.EnableField(self.c_opt_padding, False)