def test_basic(self):
sio = BytesIO(b'abcdef')
with preserve_stream_pos(sio):
sio.seek(4)
self.assertEqual(sio.tell(), 0)
sio.seek(5)
with preserve_stream_pos(sio):
sio.seek(0)
self.assertEqual(sio.tell(), 5)
def test_basic(self):
sio = BytesIO('abcdef')
with preserve_stream_pos(sio):
sio.seek(4)
self.assertEqual(stream.tell(), 0)
sio.seek(5)
with preserve_stream_pos(sio):
sio.seek(0)
self.assertEqual(stream.tell(), 5)
def get_jumptable(instrs, stream, function_start, function_end):
# get info: jump table start address (jt_addr) and how it is formatted (location_method)
lea_instr, i = get_lea(instrs)
if not i:
return None
jt_addr = lea_instr["ptr_address"]
location_method, offset_size = get_location_method(instrs, i)
# get entries
with preserve_stream_pos(stream):
stream.seek(jt_addr)
jmp_addr = get_jump_address(location_method, jt_addr, offset_size, stream)
jmp_index = 0
# maps the jumpTo address x to an array of the jump table indexes that map to x
jumps = {}
prev_jmp_addr = -1
while function_start <= jmp_addr <= function_end:
jumps = upsert(jumps, hex(jmp_addr), jmp_index, hex(prev_jmp_addr))
prev_jmp_addr = jmp_addr
jmp_addr = get_jump_address(location_method, jt_addr, offset_size, stream)
jmp_index += 1
# format jumps
res = []
for addr in jumps:
res.append({"address": addr, "indices": jumps[addr]})
res.sort(key=lambda x: x["indices"][0]) # strings (aka ranges) will be last
return res
def get_elfdata_mapping(self, elffile: ELFFile) -> bytes:
elfdata_mapping = bytearray()
# pick up elf header
with preserve_stream_pos(elffile.stream):
elffile.stream.seek(0)
elf_header = elffile.stream.read(elffile['e_ehsize'])
elfdata_mapping.extend(elf_header)
# pick up loadable sections and relocate them if needed
for sec in elffile.iter_sections():
if sec['sh_flags'] & SH_FLAGS.SHF_ALLOC:
# pad aggregated elf data to the offset of the current section
elfdata_mapping.extend(
b'\x00' * (sec['sh_offset'] - len(elfdata_mapping)))
# aggregate section data
elfdata_mapping.extend(sec.data())
return bytes(elfdata_mapping)