Cheatsheet for IDAPython

idapython_cheatsheet.md

IDAPython cheatsheet

Important links

• Porting IDAPython plugins to IDA 7.4
• Hex-Rays IDAPython official documentation

Basic commands

Get informations on the binary

info = idaapi.get_inf_structure()

entrypoint = info.start_ip
imagebase = ida_nalt.get_imagebase()
is_64bits = info.is_64bit()
is_dll = info.is_dll()
proc_name = ida_ida.inf_get_procname()

List adresses of the instructions

for ea in idautils.Heads():
  print hex(ea)

Cross-references

for ref in idautils.XrefsTo(ea):
  print hex(ref.frm)

Address name

ida_name.get_name(0, ea)
ida_name.get_name_ea(0, name) # name = "main" for example

for ea, name in idautils.Names():
  print "%x: %s" % (ea, name)

Read/Write bytes

# check the return value with the constant ida_idaapi.BADADDR
ida_bytes.get_byte(ea)
ida_bytes.get_bytes(ea, size)

ida_bytes.patch_byte(ea, byte)
ida_bytes.patch_bytes(ea, bytes)

Read address referenced by a pointer

def read_ptr(ea):
  if ida_idaapi.get_inf_structure().is_64bit():
    return ida_bytes.get_qword(ea)
  return ida_bytes.get_dword(ea)

print "%x" % read_ptr(ea)

Read string

ida_bytes.get_max_strlit_length(ea, ida_nalt.STRTYPE_C)
ida_bytes.get_strlit_contents(ea, size, ida_nalt.STRTYPE_C_16)
for c in idautils.Strings()
  print s.ea, s.length, s.strtype

Get current widget

widget = ida_kernwin.get_current_widget()
widget_type = ida_kernwin.get_widget_type(widget) # can be any of ida_kernwin.BWN_*
vdui = ida_hexrays.get_widget_vdui(widget)

Comments

# set non-repeatable comment
idc.get_cmt(ea, False)
# get repeatable comment
idc.get_cmt(ea, True)
# get func cmt
idc.get_func_cmt(ea, repeatable)

# set non-repeatable comment
idc.set_cmt(ea, comment, 0)
# set repeatable comment
idc.set_cmt(ea, comment, 1)
# set func cmt
idc.set_func_cmt(ea, comment, repeatable)

Play with segments

List segments

for s in idautils.Segments():
    start = idc.get_segm_start(s)
    end = idc.get_segm_end(s)
    name = idc.get_segm_name(s)
    data = ida_bytes.get_bytes(start, end-start)

Add segment

max_ea = ida_ida.inf_get_max_ea() # get last segment end address
idaapi.add_segm(0, start_ea, end_ea, name, sclass) # sclass can be one of "CODE", "DATA", "BSS", "STACK", "XTRN", "CONST", "ABS" or "COMM"

Play with structures and types

Create a structure

name = "my_super_structure"
struct_id = idc.add_struc(0, name, 0)

Get a structure from its name

struct_id = idaapi.get_struc_id(name)
if struct_id == idaapi.BADADDR:
    print("Structure {} does not exist".format(name))

Get structure from structure id

struct = idaapi.get_struc(struct_id)

Add member to structure

# add dword
idc.add_struc_member(struct_id, member_name, member_offset, idaapi.FF_DWORD, -1, 4) 

Set type of structure member

# define type
tinfo = idaapi.tinfo_t()
[...]
member = idaapi.get_member_by_name(struct, member_name)
if idaapi.set_member_tinfo(struct, member, 0, tinfo, 0) == idaapi.SMT_OK:
    print("Member type successfully modified !")

Apply a structure on a specific EA

idaapi.apply_tinfo(ea, tinfo, idaapi.TINFO_DEFINITE)

Play with functions

Get a function

f = ida_funcs.get_func(ea)
print "%x %x" % (f.start_ea, f.end_ea)
print ida_funcs.get_func_name(ea) # not necessarily the start ea

for ea in Functions():
  print "%x" % ea

Search a mnemonic in a function

f = ida_funcs.get_func(ea)
for ea in Heads(f.start_ea, f_end_ea):
  insn = idautils.DecodeInstruction(ea)
  if insn.itype == ida_allins.NN_call:
    print "Call at %x" % ea
  # also works to search for call instructions
  if ida_idp.is_call_insn(insn):
    print "Call at %x" % ea

Get the type and the value of an operand

# Get mov instructions to memory adresses
f = ida_funcs.get_func(ea)
for ea in Heads(f.start_ea, f_end_ea):
  insn = idautils.DecodeInstruction(ea)
  if insn.itype != ida_allins.NN_mov:
    continue
  if insn.ops[1].type == ida_ua.o_mem:
    print "Data is moved at addr %x" % insn.ops[1].value

Types returned by GetOpType:

• o_void: no operand
• o_reg: register
• o_mem: known address
• o_phrase, o_displ: pointers to adresses
• o_imm: constant value

Look for assembly code

f = ida_funcs.get_func(ea)
for ea in Heads(f.start_ea, f_end_ea):
  insn = idautils.DecodeInstruction(ea)
  if insn.itype != ida_allins.NN_xor and insn.ops[0].reg == idautils.procregs.ecx and insn.ops[1].reg == idautils.procregs.ecx:
    print "Found at addr %x" % ea

Debugger

Launch the debugger

ida_dbg.add_bpt(ea, 1, ida_idd.BPT_DEFAULT)
ida_dbg.start_process("/path/to/exe", "-q 1", "/path/to")
# bp reached
ida_dbg.continue_process()
ida_dbg.exit_process()

Breakpoint types:

• BPT_WRITE = 1
• BPT_READ = 2
• BPT_RDWD = 3
• BPT_SOFT = 4
• BPT_EXEC = 8
• BPT_DEFAULT = BPT_SOFT|BPT_EXEC

Get a memory value

rv = ida_idd.regval_t()
ida_dbg.get_reg_val("ECX", rv)
print hex(rv.ival)
print hex(idautils.cpu.ecx)

Add a script in a breakpoint

1. Add a breakpoint
2. Right click > Edit breakpoint
3. Click on the button at the right of Condition
4. Change the scripting language to Python
5. Write the code in the text zone

Call a function of the debuggee

# test check_passwd(char *passwd) -> int
passwd = ida_idd.Appcall.byref("MyFirstGuess")
res = ida_idd.Appcall.check_passwd(passwd)
if res.value == 0:
  print "Good passwd !"
else:
  print "Bad passwd..."

Other examples: http://www.hexblog.com/?p=113