Use reader instead of indexing

This commit is contained in:
Philipp Hagemeister 2013-09-21 15:32:37 +02:00
parent 8379969834
commit ba552f542f

View File

@ -590,99 +590,83 @@ def extract_tags(content):
for tag_code, tag in extract_tags(content)
if tag_code == 82)
p = code_tag.index(b'\0', 4) + 1
code_reader = io.BytesIO(code_tag[p:])
# Parse ABC (AVM2 ByteCode)
def read_int(data=None, pos=None):
if hasattr(data, 'read'):
assert pos is None
res = 0
shift = 0
for _ in range(5):
buf = data.read(1)
assert len(buf) == 1
b = struct.unpack('<B', buf)[0]
res = res | ((b & 0x7f) << shift)
if b & 0x80 == 0:
break
shift += 7
return res
if data is None:
data = code_tag
if pos is None:
pos = p
def read_int(reader=None):
if reader is None:
reader = code_reader
res = 0
shift = 0
for _ in range(5):
b = struct.unpack('<B', data[pos:pos+1])[0]
pos += 1
buf = reader.read(1)
assert len(buf) == 1
b = struct.unpack('<B', buf)[0]
res = res | ((b & 0x7f) << shift)
if b & 0x80 == 0:
break
shift += 7
return (res, pos)
assert read_int(b'\x00', 0) == (0, 1)
assert read_int(b'\x10', 0) == (16, 1)
assert read_int(b'\x34', 0) == (0x34, 1)
assert read_int(b'\xb4\x12', 0) == (0x12 * 0x80 + 0x34, 2)
assert read_int(b'\xff\xff\xff\x00', 0) == (0x1fffff, 4)
return res
def u30(*args, **kwargs):
res = read_int(*args, **kwargs)
if isinstance(res, tuple):
assert res[0] & 0xf0000000 == 0
else:
assert res & 0xf0000000 == 0
def u30(reader=None):
res = read_int(reader)
assert res & 0xf0000000 == 0
return res
u32 = read_int
def s32(data=None, pos=None):
v, pos = read_int(data, pos)
def s32(reader=None):
v = read_int(reader)
if v & 0x80000000 != 0:
v = - ((v ^ 0xffffffff) + 1)
return (v, pos)
assert s32(b'\xff\xff\xff\xff\x0f', 0) == (-1, 5)
return v
def string():
slen, p = u30()
return (code_tag[p:p+slen].decode('utf-8'), p + slen)
def string(reader=None):
if reader is None:
reader = code_reader
slen = u30(reader)
resb = reader.read(slen)
assert len(resb) == slen
return resb.decode('utf-8')
def read_byte(data=None, pos=None):
if data is None:
data = code_tag
if pos is None:
pos = p
res = struct.unpack('<B', data[pos:pos+1])[0]
return (res, pos + 1)
def read_bytes(count, reader=None):
if reader is None:
reader = code_reader
resb = reader.read(count)
assert len(resb) == count
return resb
def read_byte(reader=None):
resb = read_bytes(1, reader=reader)
res = struct.unpack('<B', resb)[0]
return res
# minor_version + major_version
p += 2 + 2
_ = read_bytes(4)
# Constant pool
int_count, p = u30()
int_count = u30()
for _c in range(1, int_count):
_, p = s32()
uint_count, p = u30()
_ = s32()
uint_count = u30()
for _c in range(1, uint_count):
_, p = u32()
double_count, p = u30()
p += (double_count-1) * 8
string_count, p = u30()
_ = u32()
double_count = u30()
_ = read_bytes((double_count-1) * 8)
string_count = u30()
constant_strings = [u'']
for _c in range(1, string_count):
s, p = string()
s = string()
constant_strings.append(s)
namespace_count, p = u30()
namespace_count = u30()
for _c in range(1, namespace_count):
p += 1 # kind
_, p = u30() # name
ns_set_count, p = u30()
_ = read_bytes(1) # kind
_ = u30() # name
ns_set_count = u30()
for _c in range(1, ns_set_count):
count, p = u30()
count = u30()
for _c2 in range(count):
_, p = u30()
multiname_count, p = u30()
_ = u30()
multiname_count = u30()
MULTINAME_SIZES = {
0x07: 2, # QName
0x0d: 2, # QNameA
@ -697,108 +681,106 @@ def read_byte(data=None, pos=None):
}
multinames = [u'']
for _c in range(1, multiname_count):
kind, p = u30()
kind = u30()
assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
if kind == 0x07:
namespace_idx, p = u30()
name_idx, p = u30()
namespace_idx = u30()
name_idx = u30()
multinames.append(constant_strings[name_idx])
else:
multinames.append('[MULTINAME kind: %d]' % kind)
for _c2 in range(MULTINAME_SIZES[kind]):
_, p = u30()
_ = u30()
# Methods
method_count, p = u30()
method_count = u30()
MethodInfo = collections.namedtuple(
'MethodInfo',
['NEED_ARGUMENTS', 'NEED_REST'])
method_infos = []
for method_id in range(method_count):
param_count, p = u30()
_, p = u30() # return type
param_count = u30()
_ = u30() # return type
for _ in range(param_count):
_, p = u30() # param type
_, p = u30() # name index (always 0 for youtube)
flags, p = read_byte()
_ = u30() # param type
_ = u30() # name index (always 0 for youtube)
flags = read_byte()
if flags & 0x08 != 0:
# Options present
option_count, p = u30()
option_count = u30()
for c in range(option_count):
_, p = u30() # val
p += 1 # kind
_ = u30() # val
_ = read_bytes(1) # kind
if flags & 0x80 != 0:
# Param names present
for _ in range(param_count):
_, p = u30() # param name
_ = u30() # param name
mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
method_infos.append(mi)
# Metadata
metadata_count, p = u30()
metadata_count = u30()
for _c in range(metadata_count):
_, p = u30() # name
item_count, p = u30()
_ = u30() # name
item_count = u30()
for _c2 in range(item_count):
_, p = u30() # key
_, p = u30() # value
_ = u30() # key
_ = u30() # value
def parse_traits_info(pos=None):
if pos is None:
pos = p
trait_name_idx, pos = u30(pos=pos)
kind_full, pos = read_byte(pos=pos)
def parse_traits_info():
trait_name_idx = u30()
kind_full = read_byte()
kind = kind_full & 0x0f
attrs = kind_full >> 4
methods = {}
if kind in [0x00, 0x06]: # Slot or Const
_, pos = u30(pos=pos) # Slot id
type_name_idx, pos = u30(pos=pos)
vindex, pos = u30(pos=pos)
_ = u30() # Slot id
type_name_idx = u30()
vindex = u30()
if vindex != 0:
_, pos = read_byte(pos=pos) # vkind
_ = read_byte() # vkind
elif kind in [0x01, 0x02, 0x03]: # Method / Getter / Setter
_, pos = u30(pos=pos) # disp_id
method_idx, pos = u30(pos=pos)
_ = u30() # disp_id
method_idx = u30()
methods[multinames[trait_name_idx]] = method_idx
elif kind == 0x04: # Class
_, pos = u30(pos=pos) # slot_id
_, pos = u30(pos=pos) # classi
_ = u30() # slot_id
_ = u30() # classi
elif kind == 0x05: # Function
_, pos = u30(pos=pos) # slot_id
function_idx, pos = u30(pos=pos)
_ = u30() # slot_id
function_idx = u30()
methods[function_idx] = multinames[trait_name_idx]
else:
raise ExtractorError(u'Unsupported trait kind %d' % kind)
if attrs & 0x4 != 0: # Metadata present
metadata_count, pos = u30(pos=pos)
metadata_count = u30()
for _c3 in range(metadata_count):
_, pos = u30(pos=pos)
_ = u30()
return (methods, pos)
return methods
# Classes
TARGET_CLASSNAME = u'SignatureDecipher'
searched_idx = multinames.index(TARGET_CLASSNAME)
searched_class_id = None
class_count, p = u30()
class_count = u30()
for class_id in range(class_count):
name_idx, p = u30()
name_idx = u30()
if name_idx == searched_idx:
# We found the class we're looking for!
searched_class_id = class_id
_, p = u30() # super_name idx
flags, p = read_byte()
_ = u30() # super_name idx
flags = read_byte()
if flags & 0x08 != 0: # Protected namespace is present
protected_ns_idx, p = u30()
intrf_count, p = u30()
protected_ns_idx = u30()
intrf_count = u30()
for _c2 in range(intrf_count):
_, p = u30()
_, p = u30() # iinit
trait_count, p = u30()
_ = u30()
_ = u30() # iinit
trait_count = u30()
for _c2 in range(trait_count):
_, p = parse_traits_info()
_ = parse_traits_info()
if searched_class_id is None:
raise ExtractorError(u'Target class %r not found' %
@ -807,10 +789,10 @@ def parse_traits_info(pos=None):
method_names = {}
method_idxs = {}
for class_id in range(class_count):
_, p = u30() # cinit
trait_count, p = u30()
_ = u30() # cinit
trait_count = u30()
for _c2 in range(trait_count):
trait_methods, p = parse_traits_info()
trait_methods = parse_traits_info()
if class_id == searched_class_id:
method_names.update(trait_methods.items())
method_idxs.update(dict(
@ -818,40 +800,40 @@ def parse_traits_info(pos=None):
for name, idx in trait_methods.items()))
# Scripts
script_count, p = u30()
script_count = u30()
for _c in range(script_count):
_, p = u30() # init
trait_count, p = u30()
_ = u30() # init
trait_count = u30()
for _c2 in range(trait_count):
_, p = parse_traits_info()
_ = parse_traits_info()
# Method bodies
method_body_count, p = u30()
method_body_count = u30()
Method = collections.namedtuple('Method', ['code', 'local_count'])
methods = {}
for _c in range(method_body_count):
method_idx, p = u30()
max_stack, p = u30()
local_count, p = u30()
init_scope_depth, p = u30()
max_scope_depth, p = u30()
code_length, p = u30()
method_idx = u30()
max_stack = u30()
local_count = u30()
init_scope_depth = u30()
max_scope_depth = u30()
code_length = u30()
code = read_bytes(code_length)
if method_idx in method_idxs:
m = Method(code_tag[p:p+code_length], local_count)
m = Method(code, local_count)
methods[method_idxs[method_idx]] = m
p += code_length
exception_count, p = u30()
exception_count = u30()
for _c2 in range(exception_count):
_, p = u30() # from
_, p = u30() # to
_, p = u30() # target
_, p = u30() # exc_type
_, p = u30() # var_name
trait_count, p = u30()
_ = u30() # from
_ = u30() # to
_ = u30() # target
_ = u30() # exc_type
_ = u30() # var_name
trait_count = u30()
for _c2 in range(trait_count):
_, p = parse_traits_info()
_ = parse_traits_info()
assert p == len(code_tag)
assert p + code_reader.tell() == len(code_tag)
assert len(methods) == len(method_idxs)
method_pyfunctions = {}