- if file_contents[1:3] != b'WS':
- raise ExtractorError(
- u'Not an SWF file; header is %r' % file_contents[:3])
- if file_contents[:1] == b'C':
- content = zlib.decompress(file_contents[8:])
- else:
- raise NotImplementedError(u'Unsupported compression format %r' %
- file_contents[:1])
-
- def extract_tags(content):
- pos = 0
- while pos < len(content):
- header16 = struct.unpack('<H', content[pos:pos+2])[0]
- pos += 2
- tag_code = header16 >> 6
- tag_len = header16 & 0x3f
- if tag_len == 0x3f:
- tag_len = struct.unpack('<I', content[pos:pos+4])[0]
- pos += 4
- assert pos+tag_len <= len(content)
- yield (tag_code, content[pos:pos+tag_len])
- pos += tag_len
-
- code_tag = next(tag
- 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(reader=None):
- if reader is None:
- reader = code_reader
- res = 0
- shift = 0
- for _ in range(5):
- 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
-
- def u30(reader=None):
- res = read_int(reader)
- assert res & 0xf0000000 == 0
- return res
- u32 = read_int
-
- def s32(reader=None):
- v = read_int(reader)
- if v & 0x80000000 != 0:
- v = - ((v ^ 0xffffffff) + 1)
- return v
-
- def read_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_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
- read_bytes(2 + 2)
-
- # Constant pool
- int_count = u30()
- for _c in range(1, int_count):
- s32()
- uint_count = u30()
- for _c in range(1, uint_count):
- u32()
- double_count = u30()
- read_bytes((double_count-1) * 8)
- string_count = u30()
- constant_strings = [u'']
- for _c in range(1, string_count):
- s = read_string()
- constant_strings.append(s)
- namespace_count = u30()
- for _c in range(1, namespace_count):
- read_bytes(1) # kind
- u30() # name
- ns_set_count = u30()
- for _c in range(1, ns_set_count):
- count = u30()
- for _c2 in range(count):
- u30()
- multiname_count = u30()
- MULTINAME_SIZES = {
- 0x07: 2, # QName
- 0x0d: 2, # QNameA
- 0x0f: 1, # RTQName
- 0x10: 1, # RTQNameA
- 0x11: 0, # RTQNameL
- 0x12: 0, # RTQNameLA
- 0x09: 2, # Multiname
- 0x0e: 2, # MultinameA
- 0x1b: 1, # MultinameL
- 0x1c: 1, # MultinameLA
- }
- multinames = [u'']
- for _c in range(1, multiname_count):
- kind = u30()
- assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
- if kind == 0x07:
- u30() # namespace_idx
- name_idx = u30()
- multinames.append(constant_strings[name_idx])
- else:
- multinames.append('[MULTINAME kind: %d]' % kind)
- for _c2 in range(MULTINAME_SIZES[kind]):
- u30()
-
- # Methods
- method_count = u30()
- MethodInfo = collections.namedtuple(
- 'MethodInfo',
- ['NEED_ARGUMENTS', 'NEED_REST'])
- method_infos = []
- for method_id in range(method_count):
- param_count = u30()
- u30() # return type
- for _ in range(param_count):
- u30() # param type
- u30() # name index (always 0 for youtube)
- flags = read_byte()
- if flags & 0x08 != 0:
- # Options present
- option_count = u30()
- for c in range(option_count):
- u30() # val
- read_bytes(1) # kind
- if flags & 0x80 != 0:
- # Param names present
- for _ in range(param_count):
- u30() # param name
- mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
- method_infos.append(mi)
-
- # Metadata
- metadata_count = u30()
- for _c in range(metadata_count):
- u30() # name
- item_count = u30()
- for _c2 in range(item_count):
- u30() # key
- u30() # value
-
- 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
- u30() # Slot id
- u30() # type_name_idx
- vindex = u30()
- if vindex != 0:
- read_byte() # vkind
- elif kind in [0x01, 0x02, 0x03]: # Method / Getter / Setter
- u30() # disp_id
- method_idx = u30()
- methods[multinames[trait_name_idx]] = method_idx
- elif kind == 0x04: # Class
- u30() # slot_id
- u30() # classi
- elif kind == 0x05: # Function
- 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 = u30()
- for _c3 in range(metadata_count):
- u30() # metadata index
-
- return methods
-
- # Classes
- TARGET_CLASSNAME = u'SignatureDecipher'
- searched_idx = multinames.index(TARGET_CLASSNAME)
- searched_class_id = None
- class_count = u30()
- for class_id in range(class_count):
- name_idx = u30()
- if name_idx == searched_idx:
- # We found the class we're looking for!
- searched_class_id = class_id
- u30() # super_name idx
- flags = read_byte()
- if flags & 0x08 != 0: # Protected namespace is present
- u30() # protected_ns_idx
- intrf_count = u30()
- for _c2 in range(intrf_count):
- u30()
- u30() # iinit
- trait_count = u30()
- for _c2 in range(trait_count):
- parse_traits_info()
-
- if searched_class_id is None:
- raise ExtractorError(u'Target class %r not found' %
- TARGET_CLASSNAME)
-
- method_names = {}
- method_idxs = {}
- for class_id in range(class_count):
- u30() # cinit
- trait_count = u30()
- for _c2 in range(trait_count):
- trait_methods = parse_traits_info()
- if class_id == searched_class_id:
- method_names.update(trait_methods.items())
- method_idxs.update(dict(
- (idx, name)
- for name, idx in trait_methods.items()))
-
- # Scripts
- script_count = u30()
- for _c in range(script_count):
- u30() # init
- trait_count = u30()
- for _c2 in range(trait_count):
- parse_traits_info()
-
- # Method bodies
- method_body_count = u30()
- Method = collections.namedtuple('Method', ['code', 'local_count'])
- methods = {}
- for _c in range(method_body_count):
- method_idx = u30()
- u30() # max_stack
- local_count = u30()
- u30() # init_scope_depth
- u30() # max_scope_depth
- code_length = u30()
- code = read_bytes(code_length)
- if method_idx in method_idxs:
- m = Method(code, local_count)
- methods[method_idxs[method_idx]] = m
- exception_count = u30()
- for _c2 in range(exception_count):
- u30() # from
- u30() # to
- u30() # target
- u30() # exc_type
- u30() # var_name
- trait_count = u30()
- for _c2 in range(trait_count):
- parse_traits_info()
-
- assert p + code_reader.tell() == len(code_tag)
- assert len(methods) == len(method_idxs)
-
- method_pyfunctions = {}
-
- def extract_function(func_name):
- if func_name in method_pyfunctions:
- return method_pyfunctions[func_name]
- if func_name not in methods:
- raise ExtractorError(u'Cannot find function %r' % func_name)
- m = methods[func_name]
-
- def resfunc(args):
- registers = ['(this)'] + list(args) + [None] * m.local_count
- stack = []
- coder = io.BytesIO(m.code)
- while True:
- opcode = struct.unpack('!B', coder.read(1))[0]
- if opcode == 36: # pushbyte
- v = struct.unpack('!B', coder.read(1))[0]
- stack.append(v)
- elif opcode == 44: # pushstring
- idx = u30(coder)
- stack.append(constant_strings[idx])
- elif opcode == 48: # pushscope
- # We don't implement the scope register, so we'll just
- # ignore the popped value
- stack.pop()
- elif opcode == 70: # callproperty
- index = u30(coder)
- mname = multinames[index]
- arg_count = u30(coder)
- args = list(reversed(
- [stack.pop() for _ in range(arg_count)]))
- obj = stack.pop()
- if mname == u'split':
- assert len(args) == 1
- assert isinstance(args[0], compat_str)
- assert isinstance(obj, compat_str)
- if args[0] == u'':
- res = list(obj)
- else:
- res = obj.split(args[0])
- stack.append(res)
- elif mname == u'slice':
- assert len(args) == 1
- assert isinstance(args[0], int)
- assert isinstance(obj, list)
- res = obj[args[0]:]
- stack.append(res)
- elif mname == u'join':
- assert len(args) == 1
- assert isinstance(args[0], compat_str)
- assert isinstance(obj, list)
- res = args[0].join(obj)
- stack.append(res)
- elif mname in method_pyfunctions:
- stack.append(method_pyfunctions[mname](args))
- else:
- raise NotImplementedError(
- u'Unsupported property %r on %r'
- % (mname, obj))
- elif opcode == 72: # returnvalue
- res = stack.pop()
- return res
- elif opcode == 79: # callpropvoid
- index = u30(coder)
- mname = multinames[index]
- arg_count = u30(coder)
- args = list(reversed(
- [stack.pop() for _ in range(arg_count)]))
- obj = stack.pop()
- if mname == u'reverse':
- assert isinstance(obj, list)
- obj.reverse()
- else:
- raise NotImplementedError(
- u'Unsupported (void) property %r on %r'
- % (mname, obj))
- elif opcode == 93: # findpropstrict
- index = u30(coder)
- mname = multinames[index]
- res = extract_function(mname)
- stack.append(res)
- elif opcode == 97: # setproperty
- index = u30(coder)
- value = stack.pop()
- idx = stack.pop()
- obj = stack.pop()
- assert isinstance(obj, list)
- assert isinstance(idx, int)
- obj[idx] = value
- elif opcode == 98: # getlocal
- index = u30(coder)
- stack.append(registers[index])
- elif opcode == 99: # setlocal
- index = u30(coder)
- value = stack.pop()
- registers[index] = value
- elif opcode == 102: # getproperty
- index = u30(coder)
- pname = multinames[index]
- if pname == u'length':
- obj = stack.pop()
- assert isinstance(obj, list)
- stack.append(len(obj))
- else: # Assume attribute access
- idx = stack.pop()
- assert isinstance(idx, int)
- obj = stack.pop()
- assert isinstance(obj, list)
- stack.append(obj[idx])
- elif opcode == 128: # coerce
- u30(coder)
- elif opcode == 133: # coerce_s
- assert isinstance(stack[-1], (type(None), compat_str))
- elif opcode == 164: # modulo
- value2 = stack.pop()
- value1 = stack.pop()
- res = value1 % value2
- stack.append(res)
- elif opcode == 208: # getlocal_0
- stack.append(registers[0])
- elif opcode == 209: # getlocal_1
- stack.append(registers[1])
- elif opcode == 210: # getlocal_2
- stack.append(registers[2])
- elif opcode == 211: # getlocal_3
- stack.append(registers[3])
- elif opcode == 214: # setlocal_2
- registers[2] = stack.pop()
- elif opcode == 215: # setlocal_3
- registers[3] = stack.pop()
- else:
- raise NotImplementedError(
- u'Unsupported opcode %d' % opcode)
-
- method_pyfunctions[func_name] = resfunc
- return resfunc
-
- initial_function = extract_function(u'decipher')
Rapsys Git / youtubedl / blobdiff