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-rw-r--r--idaSystemCalls.py328
1 files changed, 176 insertions, 152 deletions
diff --git a/idaSystemCalls.py b/idaSystemCalls.py
index 9d15d71..3bd9258 100644
--- a/idaSystemCalls.py
+++ b/idaSystemCalls.py
@@ -1,16 +1,20 @@
""" IDAPython plugin to display all system calls of AMD/Intel 32/64bit
Linux userland binaries.
-
+
Work in progress...
-
+
The system call ABI from the following link are supported.
http://esec-lab.sogeti.com/post/2011/07/05/Linux-syscall-ABI
by n0p
"""
-
+
+from miasm2.core.bin_stream_ida import bin_stream_ida
+from miasm2.analysis.depgraph import DependencyGraph
+from miasm2.analysis.machine import Machine
+
from idaapi import *
-
+
# Taken from /usr/include/asm/unistd_32.h at Arch Linux i686 3.16.3-1.
x86SystemCalls = ["sys_restart_syscall",
"sys_exit",
@@ -362,7 +366,7 @@ x86SystemCalls = ["sys_restart_syscall",
"sys_sched_setattr",
"sys_sched_getattr",
"sys_renameat2"]
-
+
# Taken from /usr/include/asm/unistd_64.h at Arch Linux x86_64 3.16.1-1.
x86_64SystemCalls = ["sys_read",
"sys_write",
@@ -680,37 +684,78 @@ x86_64SystemCalls = ["sys_read",
"sys_finit_module",
"sys_sched_setattr",
"sys_sched_getattr"]
-
+
systemCallTypes = ["int 80h", "sysenter", "syscall", "gs:[10h]"]
-
-raxVariations = ["rax", "eax", "ax", "al"]
-
-regVariations = [ ["rbx", "ebx", "bx", "bl"],
- ["rcx", "ecx", "cx", "cl"],
- ["rdx", "edx", "dx", "dl"],
- ["rsi", "esi", "si", "sil"],
- ["rdi", "edi", "di", "dil"],
- ["rbp", "ebp", "bp", "bpl"],
- ["rsp", "esp", "sp", "spl"],
- ["r8", "r8d", "r8w", "r8b"],
- ["r9", "r9d", "r9w", "r9b"],
- ["r10", "r10d", "r10w", "r10b"],
- ["r11", "r11d", "r11w", "r11b"],
- ["r12", "r12d", "r12w", "r12b"],
- ["r13", "r13d", "r13w", "r13b"],
- ["r14", "r14d", "r14w", "r14b"],
- ["r15", "r15d", "r15w", "r15b"] ]
-
-hexChars = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C",
- "D", "E", "F", "a", "b", "c", "d", "e", "f"]
-
-
+
+
+# max_size_to_size and guess_machine from miasm/example/ida/utils.py
+def max_size_to_size(max_size):
+ for size in [16, 32, 64]:
+ if (1 << size) - 1 == max_size:
+ return size
+ return None
+
+def guess_machine():
+ "Return an instance of Machine corresponding to the IDA guessed processor"
+
+ processor_name = GetLongPrm(INF_PROCNAME)
+ max_size = GetLongPrm(INF_START_SP)
+ size = max_size_to_size(max_size)
+
+ if processor_name == "metapc":
+
+ # HACK: check 32/64 using INF_START_SP
+ if max_size == 0x80: # TODO XXX check
+ machine = Machine("x86_16")
+ elif size == 32:
+ machine = Machine("x86_32")
+ elif size == 64:
+ machine = Machine("x86_64")
+ else:
+ raise ValueError('cannot guess 32/64 bit! (%x)' % max_size)
+ elif processor_name == "ARM":
+ # TODO ARM/thumb
+ # hack for thumb: set armt = True in globals :/
+ # set bigendiant = True is bigendian
+ # Thumb, size, endian
+ info2machine = {(True, 32, True): "armtb",
+ (True, 32, False): "armtl",
+ (False, 32, True): "armb",
+ (False, 32, False): "arml",
+ (False, 64, True): "aarch64b",
+ (False, 64, False): "aarch64l",
+ }
+ is_armt = globals().get('armt', False)
+ is_bigendian = globals().get('bigendian', False)
+ infos = (is_armt, size, is_bigendian)
+ if not infos in info2machine:
+ raise NotImplementedError('not fully functional')
+ machine = Machine(info2machine[infos])
+
+ from miasm2.analysis.disasm_cb import guess_funcs, guess_multi_cb
+ from miasm2.analysis.disasm_cb import arm_guess_subcall, arm_guess_jump_table
+ guess_funcs.append(arm_guess_subcall)
+ guess_funcs.append(arm_guess_jump_table)
+
+ elif processor_name == "msp430":
+ machine = Machine("msp430")
+ elif processor_name == "mipsl":
+ machine = Machine("mips32l")
+ elif processor_name == "mipsb":
+ machine = Machine("mips32b")
+ else:
+ print repr(processor_name)
+ raise NotImplementedError('not fully functional')
+
+ return machine
+
+
class SystemCallView(Choose2):
-
+
def __init__(self, systemCalls):
-
+
self.systemCalls = systemCalls
-
+
Choose2.__init__(self,
"System call",
[ ["Address", 13],
@@ -718,27 +763,27 @@ class SystemCallView(Choose2):
["Number", 10],
["Name", 20],
["Pointer Size", 12] ])
-
+
self.items = list()
-
+
self.nop_items = list()
-
+
self.icon = 150
-
+
self.cmd_nop = None
-
+
self.initialized = False
-
+
def __fillView(self):
-
+
self.systemCalls.searchSystemCalls()
-
+
self.items = list()
-
+
if len(self.systemCalls.x86) != 0:
for call in self.systemCalls.x86:
try:
- callNr = int(self.systemCalls.getSystemCallNumber(call[0]), 16)
+ callNr = int(self.systemCalls.getSystemCallNumber(call[0])[0])
self.items.append(["0x%X" % call[0],
systemCallTypes[call[1]],
"0x%03X" % callNr,
@@ -751,11 +796,11 @@ class SystemCallView(Choose2):
"",
"",
"32bit"])
-
+
if len(self.systemCalls.x86_64) != 0:
for call in self.systemCalls.x86_64:
try:
- callNr = int(self.systemCalls.getSystemCallNumber(call[0]), 16)
+ callNr = int(self.systemCalls.getSystemCallNumber(call[0])[0])
self.items.append(["0x%X" % call[0],
systemCallTypes[call[1]],
"0x%03X" % callNr,
@@ -768,147 +813,126 @@ class SystemCallView(Choose2):
"",
"",
"64bit"])
-
+
def OnClose(self):
pass
-
+
def OnCommand(self, n, cmd_id):
if cmd_id == self.cmd_nop:
start_ea = int(self.items[n][0], 16)
end_ea = start_ea+ItemSize(start_ea)
-
+
self.nop_items.append(self.items[n][0])
-
+
for i in xrange(start_ea, end_ea):
PatchByte(i, 0x90)
-
+
def OnGetIcon(self, n):
if not len(self.items) > 0:
return -1
-
+
if self.items[n][2] == "":
# No system call number found => display red icon.
return 59
else:
# Display green icon.
return 61
-
+
def OnGetLine(self, n):
return self.items[n]
-
+
def OnGetLineAttr(self, n):
if len(self.nop_items) > 0:
if self.items[n][0] in self.nop_items:
return [0xB6B6B4, 0]
-
+
def OnGetSize(self):
return len(self.items)
-
+
def OnRefresh(self, n):
self.__fillView()
-
+
def OnSelectLine(self, n):
idaapi.jumpto(int(self.items[n][0], 16))
-
+
def show(self):
if not self.initialized:
self.initialized = True
self.__fillView()
-
+
if self.Show() < 0: return False
-
+
if self.cmd_nop == None:
self.cmd_nop = self.AddCommand("NOP system call",
flags = idaapi.CHOOSER_POPUP_MENU,
icon=50)
-
+
return True
-
-
+
+
class SystemCall():
-
+
def __init__(self):
-
+
self.x86 = list()
self.x86_64 = list()
-
+
self.systemCallView = SystemCallView(self)
-
- def __formatHexStr(self, hexStr, hexLen):
-
- if hexStr[-1] == 'h':
- hexStr = hexStr[:-1]
-
- for c in hexStr:
- if not c in hexChars:
- return ""
-
- if len(hexStr) <= hexLen:
- return '0'*(hexLen-len(hexStr)) + hexStr
-
- return hexStr
-
- def __traceRegister(self, addr, targetRegVariation, xRefTo):
- """ Try to get the value of targetRegVariation at addr via back tracing.
- """
-
- try:
- funcStart = get_func(addr).startEA
- except:
- funcStart = 0
-
- while 1:
- if GetMnem(addr) == "mov":
- if GetOpnd(addr, 0) in targetRegVariation:
- # A MOV instruction with targetRegVariation as the destination
- # register.
- for regVariation in regVariations:
- if GetOpnd(addr, 1) in regVariation:
- # The source of the instruction is another register.
- # => Get the value of the destination register.
- return self.__traceRegister(addr, regVariation, addr)
-
- # We got the (possibly hex) value of the target register.
- return GetOpnd(addr, 1)
-
- if GetMnem(addr) == "lea":
- if GetOpnd(addr, 0) in targetRegVariation:
- # The value of the target register is changed but LEA is
- # currently not supported.
- break
-
- for xref in XrefsTo(addr, 0):
- # Follow all xrefs to the location and check if the target register
- # is set at this path.
- ret = self.__traceRegister(xref.frm, targetRegVariation, addr)
-
- if ret != 0xFFFFFFFF:
- return ret
-
- addr = PrevHead(addr)
-
- if addr < funcStart:
- break
-
- if addr == xRefTo:
- break
- if addr == BADADDR:
- break
- if not isCode(GetFlags(addr)):
- break
-
- return 0xFFFFFFFF
-
+
def getSystemCallNumber(self, addr):
""" Get the value of rax/eax at the time of the system call.
"""
- systemCallNumber = self.__traceRegister(PrevHead(addr), raxVariations, addr)
-
- if systemCallNumber != 0xFFFFFFFF:
- return self.__formatHexStr(systemCallNumber, 3)
-
- return ""
-
+
+ # Init
+ machine = guess_machine()
+ mn, dis_engine, ira = machine.mn, machine.dis_engine, machine.ira
+
+ bs = bin_stream_ida()
+ mdis = dis_engine(bs, dont_dis_nulstart_bloc=True)
+ ir_arch = ira(mdis.symbol_pool)
+
+ # Populate symbols with ida names
+ for ad, name in Names():
+ if name is None:
+ continue
+ mdis.symbol_pool.add_label(name, ad)
+
+ # Get the current function
+ func = idaapi.get_func(addr)
+ blocs = mdis.dis_multibloc(func.startEA)
+
+ # Generate IR
+ for bloc in blocs:
+ ir_arch.add_bloc(bloc)
+
+ cur_bloc = list(ir_arch.getby_offset(addr))[0]
+ cur_label = cur_bloc.label
+
+ elements = set([mn.regs.RAX])
+
+ for line_nb, l in enumerate(cur_bloc.lines):
+ if l.offset == addr:
+ break
+
+ # Get dependency graphs
+ dg = DependencyGraph(ir_arch, follow_call=False)
+ graphs = dg.get(cur_label, elements, line_nb,
+ set([ir_arch.symbol_pool.getby_offset(func.startEA)]))
+
+ # Display the result
+ sol = list()
+
+ while 1:
+ try:
+ graph = graphs.next()
+ except StopIteration:
+ break
+
+ if not graph.has_loop:
+ sol.append(graph.emul().values()[0])
+
+ return sol
+
def searchSystemCalls(self):
""" Looks for 'int 80', 'sysenter', 'syscall' and 'gs:[10h]' system calls.
"""
@@ -918,21 +942,21 @@ class SystemCall():
for head in Heads(segment, SegEnd(segment)):
if isCode(GetFlags(head)):
inst = DecodeInstruction(head)
-
+
if ( inst.size == 2
and get_many_bytes(head, inst.size)
.startswith("\xCD\x80")):
# int 80h. Just on 32bit.
if not [head, 0] in self.x86:
self.x86.append([head, 0])
-
+
elif ( inst.size == 2
and get_many_bytes(head, inst.size)
.startswith("\x0F\x34")):
# sysenter. Just on 32bit.
if not [head, 1] in self.x86:
self.x86.append([head, 1])
-
+
elif ( inst.size == 2
and get_many_bytes(head, inst.size)
.startswith("\x0F\x05")):
@@ -943,45 +967,45 @@ class SystemCall():
else:
if not [head, 2] in self.x86:
self.x86.append([head, 2])
-
+
elif ( inst.size == 7
and get_many_bytes(head, inst.size)
.startswith("\x65\xFF\x15\x10\x00\x00\x00")):
# gs:[10h]. Just on 32bit.
if not [head, 3] in self.x86:
self.x86.append([head, 3])
-
+
def showView(self):
self.systemCallView.show()
-
-
+
+
class SystemCallPlugin_t(idaapi.plugin_t):
flags = 0
comment = ""
help = ""
wanted_name = "System Calls"
wanted_hotkey = ""
-
+
def init(self):
global systemCalls
-
+
if idaapi.ph_get_id() == idaapi.PLFM_386:
# Check if already initialized
if not 'systemCalls' in globals():
systemCalls = SystemCall()
-
+
return idaapi.PLUGIN_KEEP
else:
return idaapi.PLUGIN_SKIP
-
+
def run(self, arg):
global systemCalls
-
+
systemCalls.showView()
-
+
def term(self):
if 'systemCalls' in globals():
del globals()['systemCalls']
-
+
def PLUGIN_ENTRY():
- return SystemCallPlugin_t() \ No newline at end of file
+ return SystemCallPlugin_t()