+from __future__ import unicode_literals
+
+import collections
+import io
+import zlib
+
+from .utils import (
+ compat_str,
+ ExtractorError,
+ struct_unpack,
+)
+
+
+def _extract_tags(file_contents):
+ if file_contents[1:3] != b'WS':
+ raise ExtractorError(
+ '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(
+ 'Unsupported compression format %r' %
+ file_contents[:1])
+
+ # Determine number of bits in framesize rectangle
+ framesize_nbits = struct_unpack('!B', content[:1])[0] >> 3
+ framesize_len = (5 + 4 * framesize_nbits + 7) // 8
+
+ pos = framesize_len + 2 + 2
+ 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), \
+ ('Tag %d ends at %d+%d - that\'s longer than the file (%d)'
+ % (tag_code, pos, tag_len, len(content)))
+ yield (tag_code, content[pos:pos + tag_len])
+ pos += tag_len
+
+
+class _AVMClass_Object(object):
+ def __init__(self, avm_class):
+ self.avm_class = avm_class
+
+ def __repr__(self):
+ return '%s#%x' % (self.avm_class.name, id(self))
+
+
+class _ScopeDict(dict):
+ def __init__(self, avm_class):
+ super(_ScopeDict, self).__init__()
+ self.avm_class = avm_class
+
+ def __repr__(self):
+ return '%s__Scope(%s)' % (
+ self.avm_class.name,
+ super(_ScopeDict, self).__repr__())
+
+
+class _AVMClass(object):
+ def __init__(self, name_idx, name):
+ self.name_idx = name_idx
+ self.name = name
+ self.method_names = {}
+ self.method_idxs = {}
+ self.methods = {}
+ self.method_pyfunctions = {}
+
+ self.variables = _ScopeDict(self)
+
+ def make_object(self):
+ return _AVMClass_Object(self)
+
+ def __repr__(self):
+ return '_AVMClass(%s)' % (self.name)
+
+ def register_methods(self, methods):
+ self.method_names.update(methods.items())
+ self.method_idxs.update(dict(
+ (idx, name)
+ for name, idx in methods.items()))
+
+
+class _Multiname(object):
+ def __init__(self, kind):
+ self.kind = kind
+
+ def __repr__(self):
+ return '[MULTINAME kind: 0x%x]' % self.kind
+
+
+def _read_int(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):
+ res = _read_int(reader)
+ assert res & 0xf0000000 == 0
+ return res
+_u32 = _read_int
+
+
+def _s32(reader):
+ v = _read_int(reader)
+ if v & 0x80000000 != 0:
+ v = - ((v ^ 0xffffffff) + 1)
+ return v
+
+
+def _s24(reader):
+ bs = reader.read(3)
+ assert len(bs) == 3
+ last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
+ return struct_unpack('<i', bs + last_byte)[0]
+
+
+def _read_string(reader):
+ slen = _u30(reader)
+ resb = reader.read(slen)
+ assert len(resb) == slen
+ return resb.decode('utf-8')
+
+
+def _read_bytes(count, reader):
+ assert count >= 0
+ resb = reader.read(count)
+ assert len(resb) == count
+ return resb
+
+
+def _read_byte(reader):
+ resb = _read_bytes(1, reader=reader)
+ res = struct_unpack('<B', resb)[0]
+ return res
+
+
+class SWFInterpreter(object):
+ def __init__(self, file_contents):
+ code_tag = next(tag
+ for tag_code, tag in _extract_tags(file_contents)
+ if tag_code == 82)
+ p = code_tag.index(b'\0', 4) + 1
+ code_reader = io.BytesIO(code_tag[p:])
+
+ # Parse ABC (AVM2 ByteCode)
+
+ # Define a couple convenience methods
+ u30 = lambda *args: _u30(*args, reader=code_reader)
+ s32 = lambda *args: _s32(*args, reader=code_reader)
+ u32 = lambda *args: _u32(*args, reader=code_reader)
+ read_bytes = lambda *args: _read_bytes(*args, reader=code_reader)
+ read_byte = lambda *args: _read_byte(*args, reader=code_reader)
+
+ # 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(max(0, (double_count - 1)) * 8)
+ string_count = u30()
+ self.constant_strings = ['']
+ for _c in range(1, string_count):
+ s = _read_string(code_reader)
+ self.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
+ }
+ self.multinames = ['']
+ for _c in range(1, multiname_count):
+ kind = u30()
+ assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind
+ if kind == 0x07:
+ u30() # namespace_idx
+ name_idx = u30()
+ self.multinames.append(self.constant_strings[name_idx])
+ else:
+ self.multinames.append(_Multiname(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[self.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] = self.multinames[trait_name_idx]
+ else:
+ raise ExtractorError('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
+ class_count = u30()
+ classes = []
+ for class_id in range(class_count):
+ name_idx = u30()
+
+ cname = self.multinames[name_idx]
+ avm_class = _AVMClass(name_idx, cname)
+ classes.append(avm_class)
+
+ 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):
+ trait_methods = parse_traits_info()
+ avm_class.register_methods(trait_methods)
+
+ assert len(classes) == class_count
+ self._classes_by_name = dict((c.name, c) for c in classes)
+
+ for avm_class in classes:
+ u30() # cinit
+ trait_count = u30()
+ for _c2 in range(trait_count):
+ trait_methods = parse_traits_info()
+ avm_class.register_methods(trait_methods)
+
+ # 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'])
+ 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)
+ for avm_class in classes:
+ if method_idx in avm_class.method_idxs:
+ m = Method(code, local_count)
+ avm_class.methods[avm_class.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)
+
+ def extract_class(self, class_name):
+ try:
+ return self._classes_by_name[class_name]
+ except KeyError:
+ raise ExtractorError('Class %r not found' % class_name)
+
+ def extract_function(self, avm_class, func_name):
+ if func_name in avm_class.method_pyfunctions:
+ return avm_class.method_pyfunctions[func_name]
+ if func_name in self._classes_by_name:
+ return self._classes_by_name[func_name].make_object()
+ if func_name not in avm_class.methods:
+ raise ExtractorError('Cannot find function %s.%s' % (
+ avm_class.name, func_name))
+ m = avm_class.methods[func_name]
+
+ def resfunc(args):
+ # Helper functions
+ coder = io.BytesIO(m.code)
+ s24 = lambda: _s24(coder)
+ u30 = lambda: _u30(coder)
+
+ registers = [avm_class.variables] + list(args) + [None] * m.local_count
+ stack = []
+ scopes = collections.deque([
+ self._classes_by_name, avm_class.variables])
+ while True:
+ opcode = _read_byte(coder)
+ if opcode == 17: # iftrue
+ offset = s24()
+ value = stack.pop()
+ if value:
+ coder.seek(coder.tell() + offset)
+ elif opcode == 18: # iffalse
+ offset = s24()
+ value = stack.pop()
+ if not value:
+ coder.seek(coder.tell() + offset)
+ elif opcode == 36: # pushbyte
+ v = _read_byte(coder)
+ stack.append(v)
+ elif opcode == 42: # dup
+ value = stack[-1]
+ stack.append(value)
+ elif opcode == 44: # pushstring
+ idx = u30()
+ stack.append(self.constant_strings[idx])
+ elif opcode == 48: # pushscope
+ new_scope = stack.pop()
+ scopes.append(new_scope)
+ elif opcode == 66: # construct
+ arg_count = u30()
+ args = list(reversed(
+ [stack.pop() for _ in range(arg_count)]))
+ obj = stack.pop()
+ res = obj.avm_class.make_object()
+ stack.append(res)
+ elif opcode == 70: # callproperty
+ index = u30()
+ mname = self.multinames[index]
+ arg_count = u30()
+ args = list(reversed(
+ [stack.pop() for _ in range(arg_count)]))
+ obj = stack.pop()
+
+ if isinstance(obj, _AVMClass_Object):
+ func = self.extract_function(obj.avm_class, mname)
+ res = func(args)
+ stack.append(res)
+ continue
+ elif isinstance(obj, _ScopeDict):
+ if mname in obj.avm_class.method_names:
+ func = self.extract_function(obj.avm_class, mname)
+ res = func(args)
+ else:
+ res = obj[mname]
+ stack.append(res)
+ continue
+ elif isinstance(obj, compat_str):
+ if mname == 'split':
+ assert len(args) == 1
+ assert isinstance(args[0], compat_str)
+ if args[0] == '':
+ res = list(obj)
+ else:
+ res = obj.split(args[0])
+ stack.append(res)
+ continue
+ elif isinstance(obj, list):
+ if mname == 'slice':
+ assert len(args) == 1
+ assert isinstance(args[0], int)
+ res = obj[args[0]:]
+ stack.append(res)
+ continue
+ elif mname == 'join':
+ assert len(args) == 1
+ assert isinstance(args[0], compat_str)
+ res = args[0].join(obj)
+ stack.append(res)
+ continue
+ raise NotImplementedError(
+ 'Unsupported property %r on %r'
+ % (mname, obj))
+ elif opcode == 72: # returnvalue
+ res = stack.pop()
+ return res
+ elif opcode == 74: # constructproperty
+ index = u30()
+ arg_count = u30()
+ args = list(reversed(
+ [stack.pop() for _ in range(arg_count)]))
+ obj = stack.pop()
+
+ mname = self.multinames[index]
+ assert isinstance(obj, _AVMClass)
+
+ # We do not actually call the constructor for now;
+ # we just pretend it does nothing
+ stack.append(obj.make_object())
+ elif opcode == 79: # callpropvoid
+ index = u30()
+ mname = self.multinames[index]
+ arg_count = u30()
+ args = list(reversed(
+ [stack.pop() for _ in range(arg_count)]))
+ obj = stack.pop()
+ if mname == 'reverse':
+ assert isinstance(obj, list)
+ obj.reverse()
+ else:
+ raise NotImplementedError(
+ 'Unsupported (void) property %r on %r'
+ % (mname, obj))
+ elif opcode == 86: # newarray
+ arg_count = u30()
+ arr = []
+ for i in range(arg_count):
+ arr.append(stack.pop())
+ arr = arr[::-1]
+ stack.append(arr)
+ elif opcode == 93: # findpropstrict
+ index = u30()
+ mname = self.multinames[index]
+ for s in reversed(scopes):
+ if mname in s:
+ res = s
+ break
+ else:
+ res = scopes[0]
+ stack.append(res[mname])
+ elif opcode == 94: # findproperty
+ index = u30()
+ mname = self.multinames[index]
+ for s in reversed(scopes):
+ if mname in s:
+ res = s
+ break
+ else:
+ res = avm_class.variables
+ stack.append(res)
+ elif opcode == 96: # getlex
+ index = u30()
+ mname = self.multinames[index]
+ for s in reversed(scopes):
+ if mname in s:
+ scope = s
+ break
+ else:
+ scope = avm_class.variables
+ # I cannot find where static variables are initialized
+ # so let's just return None
+ res = scope.get(mname)
+ stack.append(res)
+ elif opcode == 97: # setproperty
+ index = u30()
+ value = stack.pop()
+ idx = self.multinames[index]
+ if isinstance(idx, _Multiname):
+ idx = stack.pop()
+ obj = stack.pop()
+ obj[idx] = value
+ elif opcode == 98: # getlocal
+ index = u30()
+ stack.append(registers[index])
+ elif opcode == 99: # setlocal
+ index = u30()
+ value = stack.pop()
+ registers[index] = value
+ elif opcode == 102: # getproperty
+ index = u30()
+ pname = self.multinames[index]
+ if pname == '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 == 115: # convert_
+ value = stack.pop()
+ intvalue = int(value)
+ stack.append(intvalue)
+ elif opcode == 128: # coerce
+ u30()
+ elif opcode == 133: # coerce_s
+ assert isinstance(stack[-1], (type(None), compat_str))
+ elif opcode == 160: # add
+ value2 = stack.pop()
+ value1 = stack.pop()
+ res = value1 + value2
+ stack.append(res)
+ elif opcode == 161: # subtract
+ value2 = stack.pop()
+ value1 = stack.pop()
+ res = value1 - value2
+ stack.append(res)
+ elif opcode == 164: # modulo
+ value2 = stack.pop()
+ value1 = stack.pop()
+ res = value1 % value2
+ stack.append(res)
+ elif opcode == 175: # greaterequals
+ value2 = stack.pop()
+ value1 = stack.pop()
+ result = value1 >= value2
+ stack.append(result)
+ 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 == 212: # setlocal_0
+ registers[0] = stack.pop()
+ elif opcode == 213: # setlocal_1
+ registers[1] = stack.pop()
+ elif opcode == 214: # setlocal_2
+ registers[2] = stack.pop()
+ elif opcode == 215: # setlocal_3
+ registers[3] = stack.pop()
+ else:
+ raise NotImplementedError(
+ 'Unsupported opcode %d' % opcode)
+
+ avm_class.method_pyfunctions[func_name] = resfunc
+ return resfunc
+
Rapsys Git / youtubedl / commitdiff