class EXCEPTION_REGISTRATION_RECORD(MemStruct):
"""
+0x00 Next : struct _EXCEPTION_REGISTRATION_RECORD *
+0x04 Handler : Ptr32 Void
"""
fields = [
("Next", Ptr("<I", Self())),
("Handler", Ptr("<I", Void())),
]
class UnhealthyIdeas(MemStruct):
fields = [
("pastruct", Ptr("I", Array(RawStruct("=Bf")))),
("apstr", Array(Ptr("I", Str()), 10)),
("pself", Ptr("I", Self())),
("apself", Array(Ptr("I", Self()), 2)),
("ppself", Ptr("I", Ptr("I", Self()))),
("pppself", Ptr("I", Ptr("I", Ptr("I", Self())))),
]
class MyStruct(MemStruct):
fields = [
# Number field: just struct.pack fields with one value
("num", Num("I")),
("flags", Num("B")),
# This field is a pointer to another struct, it has a numeric
# value (mystruct.other.val) and can be dereferenced to get an
# OtherStruct instance (mystruct.other.deref)
("other", Ptr("I", OtherStruct)),
# Ptr to a variable length String
("s", Ptr("I", Str())),
("i", Ptr("I", Num("I"))),
]
class EXCEPTION_RECORD(MemStruct):
"""
DWORD ExceptionCode;
DWORD ExceptionFlags;
struct _EXCEPTION_RECORD *ExceptionRecord;
PVOID ExceptionAddress;
DWORD NumberParameters;
ULONG_PTR ExceptionInformation[EXCEPTION_MAXIMUM_PARAMETERS];
"""
EXCEPTION_MAXIMUM_PARAMETERS = 15
fields = [
("ExceptionCode", Num("<I")),
("ExceptionFlags", Num("<I")),
("ExceptionRecord", Ptr("<I", Self())),
("ExceptionAddress", Ptr("<I", Void())),
("NumberParameters", Num("<I")),
("ExceptionInformation", Ptr("<I", Void())),
]
class DataArray(MemStruct):
fields = [
("val1", Num("B")),
("val2", Num("B")),
# Ptr can also be instanciated with a Type instance as an argument, the
# corresponding Memtype will be returned when dereferencing
# Here, data_array.array.deref will allow to access an Array
("arrayptr", Ptr("<I", Array(Num("B"), 16))),
# Array of 10 uint8
("array", Array(Num("B"), 16)),
]
class PEB(MemStruct):
"""
+0x000 InheritedAddressSpace : UChar
+0x001 ReadImageFileExecOptions : UChar
+0x002 BeingDebugged : UChar
+0x003 SpareBool : UChar
+0x004 Mutant : Ptr32 Void
+0x008 ImageBaseAddress : Ptr32 Void
+0x00c Ldr : Ptr32 _PEB_LDR_DATA
+0x010 processparameter
"""
fields = [
("InheritedAddressSpace", Num("B")),
("ReadImageFileExecOptions", Num("B")),
("BeingDebugged", Num("B")),
("SpareBool", Num("B")),
("Mutant", Ptr("<I", Void())),
("ImageBaseAddress", Num("<I")),
("Ldr", Ptr("<I", PEB_LDR_DATA)),
]
class TEB(MemStruct):
"""
+0x000 NtTib : _NT_TIB
+0x01c EnvironmentPointer : Ptr32 Void
+0x020 ClientId : _CLIENT_ID
+0x028 ActiveRpcHandle : Ptr32 Void
+0x02c ThreadLocalStoragePointer : Ptr32 Void
+0x030 ProcessEnvironmentBlock : Ptr32 _PEB
+0x034 LastErrorValue : Uint4B
...
"""
fields = [
("NtTib", NT_TIB),
("EnvironmentPointer", Ptr("<I", Void())),
("ClientId", Array(Num("B"), 0x8)),
("ActiveRpcHandle", Ptr("<I", Void())),
("ThreadLocalStoragePointer", Ptr("<I", Void())),
("ProcessEnvironmentBlock", Ptr("<I", PEB)),
("LastErrorValue", Num("<I")),
]
class ListNode(MemStruct):
fields = [
# The "<I" is the struct-like format of the pointer in memory, in this
# case a Little Endian 32 bits unsigned int.
# One way to handle reference to ListNode in ListNode is to use the
# special marker Self().
# You could also generate ListNode's fields with ListNode.gen_field
# after the class declaration, so that the ListNode is defined when
# fields are generated.
("next", Ptr("<I", Self())),
# Ptr(_, Void()) is analogous to void*, Void() is a kind of "empty type"
("data", Ptr("<I", Void())),
]
def get_next(self):
if self.next.val == 0:
return None
return self.next.deref
def get_data(self, data_type=None):
if data_type is not None:
return self.data.deref.cast(data_type)
else:
return self.data.deref
class PEB_LDR_DATA(MemStruct):
"""
+0x000 Length : Uint4B
+0x004 Initialized : UChar
+0x008 SsHandle : Ptr32 Void
+0x00c InLoadOrderModuleList : _LIST_ENTRY
+0x014 InMemoryOrderModuleList : _LIST_ENTRY
+0x01C InInitializationOrderModuleList : _LIST_ENTRY
"""
fields = [("Length", Num("<I")), ("Initialized", Num("<I")),
("SsHandle", Ptr("<I", Void())),
("InLoadOrderModuleList", ListEntry),
("InMemoryOrderModuleList", ListEntry),
("InInitializationOrderModuleList", ListEntry)]
class LdrDataEntry(MemStruct):
"""
+0x000 InLoadOrderLinks : _LIST_ENTRY
+0x008 InMemoryOrderLinks : _LIST_ENTRY
+0x010 InInitializationOrderLinks : _LIST_ENTRY
+0x018 DllBase : Ptr32 Void
+0x01c EntryPoint : Ptr32 Void
+0x020 SizeOfImage : Uint4B
+0x024 FullDllName : _UNICODE_STRING
+0x02c BaseDllName : _UNICODE_STRING
+0x034 Flags : Uint4B
+0x038 LoadCount : Uint2B
+0x03a TlsIndex : Uint2B
+0x03c HashLinks : _LIST_ENTRY
+0x03c SectionPointer : Ptr32 Void
+0x040 CheckSum : Uint4B
+0x044 TimeDateStamp : Uint4B
+0x044 LoadedImports : Ptr32 Void
+0x048 EntryPointActivationContext : Ptr32 Void
+0x04c PatchInformation : Ptr32 Void
"""
fields = [
("InLoadOrderLinks", ListEntry),
("InMemoryOrderLinks", ListEntry),
("InInitializationOrderLinks", ListEntry),
("DllBase", Ptr("<I", Void())),
("EntryPoint", Ptr("<I", Void())),
("SizeOfImage", Num("<I")),
("FullDllName", UnicodeString),
("BaseDllName", UnicodeString),
("Flags", Array(Num("B"), 4)),
("LoadCount", Num("H")),
("TlsIndex", Num("H")),
("union1",
Union([
("HashLinks", Ptr("<I", Void())),
("SectionPointer", Ptr("<I", Void())),
])),
("CheckSum", Num("<I")),
("union2",
Union([
("TimeDateStamp", Num("<I")),
("LoadedImports", Ptr("<I", Void())),
])),
("EntryPointActivationContext", Ptr("<I", Void())),
("PatchInformation", Ptr("<I", Void())),
]
class NT_TIB(MemStruct):
"""
+00 struct _EXCEPTION_REGISTRATION_RECORD *ExceptionList
+04 void *StackBase
+08 void *StackLimit
+0c void *SubSystemTib
+10 void *FiberData
+10 uint32 Version
+14 void *ArbitraryUserPointer
+18 struct _NT_TIB *Self
"""
fields = [
("ExceptionList", Ptr("<I", EXCEPTION_REGISTRATION_RECORD)),
("StackBase", Ptr("<I", Void())),
("StackLimit", Ptr("<I", Void())),
("SubSystemTib", Ptr("<I", Void())),
(None, Union([("FiberData", Ptr("<I", Void())),
("Version", Num("<I"))])),
("ArbitraryUserPointer", Ptr("<I", Void())),
("Self", Ptr("<I", Self())),
]
assert bit.flags.f4_1 == 1
# Unhealthy ideas
class UnhealthyIdeas(MemStruct):
fields = [
("pastruct", Ptr("I", Array(RawStruct("=Bf")))),
("apstr", Array(Ptr("I", Str()), 10)),
("pself", Ptr("I", Self())),
("apself", Array(Ptr("I", Self()), 2)),
("ppself", Ptr("I", Ptr("I", Self()))),
("pppself", Ptr("I", Ptr("I", Ptr("I", Self())))),
]
p_size = Ptr("I", Void()).size
ideas = UnhealthyIdeas(jitter.vm)
ideas.memset()
ideas.pself = ideas.get_addr()
assert ideas == ideas.pself.deref
ideas.apself[0] = ideas.get_addr()
assert ideas.apself[0].deref == ideas
ideas.apself[1] = my_heap.vm_alloc(jitter.vm, UnhealthyIdeas.sizeof())
ideas.apself[1].deref = ideas
assert ideas.apself[1] != ideas.get_addr()
assert ideas.apself[1].deref == ideas
ideas.ppself = my_heap.vm_alloc(jitter.vm, p_size)
ideas.ppself.deref.val = ideas.get_addr()
class LinkedList(MemStruct):
fields = [
# For convenience, either a Type instance (like Self() or Num("I") or a
# MemStruct subclass can be passed to the Ptr constructor.
("head", Ptr("<I", ListNode)),
("tail", Ptr("<I", ListNode)),
# Num can take any one-field struct-like format, including floats and
# doubles
("size", Num("<I")),
]
def get_head(self):
"""Returns the head ListNode instance"""
if self.head == 0:
return None
return self.head.deref
def get_tail(self):
"""Returns the tail ListNode instance"""
if self.tail == 0:
return None
return self.tail.deref
def push(self, data):
"""Push a data (MemType instance) to the linked list."""
# Allocate a new node
node = ListNode(self._vm)
# Set the data pointer
node.data = data.get_addr()
# re-link
if self.head != 0:
# get the head ListNode
head = self.get_head()
node.next = head.get_addr()
# pointer to head assigned to the new node address
self.head = node.get_addr()
# Do not forget the tail :)
if self.tail == 0:
self.tail = node.get_addr()
self.size += 1
def pop(self, data_type=None):
"""Pop one data from the LinkedList."""
# Nothing to pop
if self.head == 0:
return None
node = self.get_head()
self.head = node.next
# empty
if self.head == 0:
self.tail = 0
self.size -= 1
return node.get_data(data_type)
def empty(self):
"""True if the list is empty."""
return self.head == 0
def __iter__(self):
if not self.empty():
cur = self.get_head()
while cur is not None:
yield cur.data.deref
cur = cur.get_next()
class DataStr(MemStruct):
fields = [
("valshort", Num("<H")),
# Pointer to an utf16 null terminated string
("data", Ptr("<I", Str("utf16"))),
]
class UnicodeString(MemStruct):
fields = [
("length", Num("H")),
("maxlength", Num("H")),
("data", Ptr("<I", Str("utf16"))),
]
class ListEntry(MemStruct):
fields = [
("flink", Ptr("<I", Void())),
("blink", Ptr("<I", Void())),
]
class B(MemStruct):
fields = [
("a", Ptr("I", A)),
]
raw_miams_array = [ord(c) for c in raw_miams]
assert list(data.array)[:len(raw_miams_array)] == raw_miams_array
assert data.array.cast(Str("utf16")) == memstr
# Default is "ansi"
assert data.array.cast(Str()) != memstr
assert data.array.cast(Str("utf16")).val == memstr.val
print "See that the original array has been modified:"
print repr(data)
print
# Some type manipulation examples, for example let's construct an argv for
# a program:
# Let's say that we have two arguments, +1 for the program name and +1 for the
# final null ptr in argv, the array has 4 elements:
argv_t = Array(Ptr("<I", Str()), 4)
print "3 arguments argv type:", argv_t
# alloc argv somewhere
argv = argv_t.lval(vm)
# Auto alloc with the MemStr.from_str helper
MemStrAnsi = Str().lval
argv[0].val = MemStrAnsi.from_str(vm, "./my-program").get_addr()
argv[1].val = MemStrAnsi.from_str(vm, "arg1").get_addr()
argv[2].val = MemStrAnsi.from_str(vm, "27").get_addr()
argv[3].val = 0
# If you changed your mind on the second arg, you could do:
argv[2].deref.val = "42"