def _initInternalDict(self):
self.dict = CachedItemDictionary()
strings_ids = self.strings_ids.getRawData()
instance_type = Data.getInstance(strings_ids)
self.dict.createTypeDictionary(instance_type)
self.dict.fillPairsDict(instance_type, strings_ids,
lambda x: IndexedItemsValues(x.get_off()))
type_ids = self.type_ids.getRawData()
instance_type = Data.getInstance(type_ids)
self.dict.createTypeDictionary(instance_type)
self.dict.fillPairsDict(
instance_type, type_ids,
lambda x: IndexedItemsValues(x.get_descriptor_idx()))
"""
def saveSectionChanges(self, section):
andro_obj = section.getAndroguardObj()
if andro_obj:
mapped_obj = Data.getInstance(andro_obj)
if mapped_obj:
# Really, what i am thinking.
# Maybe the slowest, but i think it is unavoidable?
# self.__map.get_item_type(TYPE_MAP_ITEM[mapped_obj.get_type()])
# = copy.deepcopy(andro_obj)
pass
def _placeItems(self):
elem = Data.getInstance(self.object)
"""
According to source code we have that sections:
- header
- stringids
- typeids
- protoids
- fieldids
- methodids
- classdefs
are extending UniformItemSection which has the following
implementation to calculate WriteSize:
(It is a constant independed number instead on relying on
the class value like StringDataItem)
public final int writeSize() {
Collection<? extends Item> items = items();
int sz = items.size();
if (sz == 0) {
return 0;
}
// Since each item has to be the same size, we can pick any.
return sz * items.iterator().next().writeSize();
}
We can easily point out now that, in order to calculate the
writesize of our section, we must first check what kind of
class we are holding on and then, calculate the data size with
the help of Androguard's functions.
It is possible, due to being CPU-consuming, to perform some
other calculations here too which are based on the kind of instance
that self.object is pointed to.
"""
# TODO - Combine in an OR clause the items that have the same writesize
# also use else if?
if isinstance(elem, HeaderItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/HeaderItem.java#55
self.instance_write_size = HEADER_SIZE
self.data = self.object
self.write_size = self.instance_write_size
self.callback = SectionWriter.writeHeaderSection
if isinstance(elem, StringIdItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/StringIdItem.java#29
self.instance_write_size = 4
# Assign array of Items to .data property
self.data = self.object
# Set write size
self.write_size = self.instance_write_size * len(self.data)
# set write callback
self.callback = SectionWriter.writeStringIdSection
if isinstance(elem, TypeHIdItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/TypeIdItem.java#29
self.instance_write_size = 4
# Assign array of Items to .data property
self.data = self.object.get_type()
self.write_size = self.instance_write_size * len(self.data)
self.callback = SectionWriter.writeTypeIdSection
if isinstance(elem, ProtoHIdItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/ProtoIdItem.java#32
self.instance_write_size = 12
# Assign array of Items to .data property
self.data = self.object.get_obj()
self.write_size = self.instance_write_size * len(self.data)
self.callback = SectionWriter.writeProtoIdSection
if isinstance(elem, FieldHIdItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/MemberIdItem.java#30
self.instance_write_size = 8
# Assign array of Items to .data property
self.data = self.object.get_obj()
self.write_size = self.instance_write_size * len(self.data)
self.callback = SectionWriter.writeFieldIdSection
if isinstance(elem, MethodHIdItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/MemberIdItem.java#30
self.instance_write_size = 8
# Assign array of Items to .data property
self.data = self.object.get_obj()
self.write_size = self.instance_write_size * len(self.data)
self.callback = SectionWriter.writeMethodIdSection
if isinstance(elem, ClassHDefItem):
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/ClassDefItem.java#46
self.instance_write_size = 32
# Assign array of Items to .data property
self.data = self.object.get_obj()
self.write_size = self.instance_write_size * len(self.data)
self.callback = SectionWriter.writeClassDefSection
def _placeItems(self):
elem = Data.getInstance(self.object)
writer_offset = 0
if isinstance(elem, StringDataItem):
self.data = self.object
self.callback = SectionWriter.writeStringDataSection
# How convinient to have access to such great methods :)
for item in self.data:
# https://github.com/androguard/androguard/blob/v2.0/androguard/core/bytecodes/dvm.py#L1775
off = Data.toAligned(self.alignment, writer_offset)
item.set_off(off)
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/MixedItemSection.java#319
# print binascii.hexlify(writeuleb128(item.get_utf16_size()))
writer_offset = off + \
(len(writeuleb128(item.get_utf16_size())) +
len(item.get_data()) + 1)
# With a little luck, it might work ...
self.callback = SectionWriter.writeStringDataSection
elif isinstance(elem, ClassDataItem):
self.data = self.object
self.callback = SectionWriter.writeClassDataSection
for item in self.object:
off = Data.toAligned(self.alignment, writer_offset)
item.set_off(off)
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/MixedItemSection.java#319
# https://github.com/androguard/androguard/blob/v2.0/androguard/core/bytecodes/dvm.py#L3167
writer_offset = off + item.get_length()
elif isinstance(elem, CodeItem):
self.data = self.object.get_obj()
# https://github.com/androguard/androguard/blob/v2.0/androguard/core/bytecodes/dvm.py#L6667
for item in self.data:
# We are looping through DalvikCode items
off = Data.toAligned(self.alignment, writer_offset)
item.set_off(off)
writer_offset = off + item.get_size()
if writer_offset != self.object.get_length():
print '[-] Expected a total length of {0} but generated {1}'.format(
self.object.get_length(), writer_offset)
elif isinstance(elem, TypeList):
self.data = self.object
self.callback = SectionWriter.writeTypeListSection
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/TypeListItem.java#48
self.instance_write_size = 2
#self.write_size = len(self.data * self.instance_write_size) + 4
for items in self.data:
its = items.get_list()
writer_offset += (len(its) * self.instance_write_size) + 4
'''
Androguard does not have at v2 functions or properties related
to offsets.
So, this :
for item in self.object.get_list():
off = Data.toAligned(writer_offset)
item.off = off
writer_offset = off + self.instance_write_size
Is not necessary for now.
'''
elif isinstance(elem, MapList):
self.data = self.object.map_item
# https://android.googlesource.com/platform/dalvik/+/master/dexgen/src/com/android/dexgen/dex/file/MapItem.java#32
self.instance_write_size = 3 * 4
self.callback = SectionWriter.writeMapItemSection
self.write_size = len(
self.object.get_obj()) * self.instance_write_size
# Abuse of property - wish there was a function instead for optical
# pleasure :/
for item in self.data:
off = Data.toAligned(self.alignment, writer_offset)
# Abuse of property again :/ :/
item.off = off
writer_offset = off + self.instance_write_size
# Set write size
if self.write_size == 0:
self.write_size = writer_offset
