import collections
import io
-import struct
import zlib
-from .utils import ExtractorError
-
-
-def _extract_tags(content):
- pos = 0
+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]
+ 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]
+ tag_len = struct_unpack('<I', content[pos:pos + 4])[0]
pos += 4
- assert pos + tag_len <= len(content)
+ 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
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.method_idxs = {}
self.methods = {}
self.method_pyfunctions = {}
- self.variables = {}
+
+ 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
for _ in range(5):
buf = reader.read(1)
assert len(buf) == 1
- b = struct.unpack('<B', buf)[0]
+ b = struct_unpack('<B', buf)[0]
res = res | ((b & 0x7f) << shift)
if b & 0x80 == 0:
break
res = _read_int(reader)
assert res & 0xf0000000 == 0
return res
-u32 = _read_int
+_u32 = _read_int
def _s32(reader):
def _s24(reader):
bs = reader.read(3)
assert len(bs) == 3
- first_byte = b'\xff' if (ord(bs[0:1]) >= 0x80) else b'\x00'
- return struct.unpack('!i', first_byte + bs)
+ 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):
def _read_bytes(count, reader):
- if reader is None:
- reader = code_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]
+ res = struct_unpack('<B', resb)[0]
return res
class SWFInterpreter(object):
def __init__(self, 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])
-
+ self._patched_functions = {}
code_tag = next(tag
- for tag_code, tag in _extract_tags(content)
+ 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:])
for _c in range(1, uint_count):
u32()
double_count = u30()
- read_bytes((double_count - 1) * 8)
+ read_bytes(max(0, (double_count - 1)) * 8)
string_count = u30()
- constant_strings = ['']
+ self.constant_strings = ['']
for _c in range(1, string_count):
s = _read_string(code_reader)
- constant_strings.append(s)
+ self.constant_strings.append(s)
namespace_count = u30()
for _c in range(1, namespace_count):
read_bytes(1) # kind
if kind == 0x07:
u30() # namespace_idx
name_idx = u30()
- self.multinames.append(constant_strings[name_idx])
+ self.multinames.append(self.constant_strings[name_idx])
+ elif kind == 0x09:
+ name_idx = u30()
+ u30()
+ self.multinames.append(self.constant_strings[name_idx])
else:
- self.multinames.append('[MULTINAME kind: %d]' % kind)
+ self.multinames.append(_Multiname(kind))
for _c2 in range(MULTINAME_SIZES[kind]):
u30()
classes = []
for class_id in range(class_count):
name_idx = u30()
- classes.append(_AVMClass(name_idx, self.multinames[name_idx]))
+
+ 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() # iinit
trait_count = u30()
for _c2 in range(trait_count):
- parse_traits_info()
+ 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)
trait_count = u30()
for _c2 in range(trait_count):
trait_methods = parse_traits_info()
- avm_class.method_names.update(trait_methods.items())
- avm_class.method_idxs.update(dict(
- (idx, name)
- for name, idx in trait_methods.items()))
+ avm_class.register_methods(trait_methods)
# Scripts
script_count = u30()
assert p + code_reader.tell() == len(code_tag)
+ def patch_function(self, avm_class, func_name, f):
+ self._patched_functions[(avm_class, func_name)] = f
+
def extract_class(self, class_name):
try:
return self._classes_by_name[class_name]
raise ExtractorError('Class %r not found' % class_name)
def extract_function(self, avm_class, func_name):
+ p = self._patched_functions.get((avm_class, func_name))
+ if p:
+ return p
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 %r' % func_name)
+ raise ExtractorError('Cannot find function %s.%s' % (
+ avm_class.name, func_name))
m = avm_class.methods[func_name]
def resfunc(args):
s24 = lambda: _s24(coder)
u30 = lambda: _u30(coder)
- print('Invoking %s.%s(%r)' % (avm_class.name, func_name, tuple(args)))
- registers = ['(this)'] + list(args) + [None] * m.local_count
+ 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)
- print('opcode: %r, stack(%d): %r' % (opcode, len(stack), stack))
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(constant_strings[idx])
+ stack.append(self.constant_strings[idx])
elif opcode == 48: # pushscope
- # We don't implement the scope register, so we'll just
- # ignore the popped value
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]
args = list(reversed(
[stack.pop() for _ in range(arg_count)]))
obj = stack.pop()
- if mname == 'split':
- assert len(args) == 1
- assert isinstance(args[0], compat_str)
- assert isinstance(obj, compat_str)
- if args[0] == '':
- res = list(obj)
- else:
- res = obj.split(args[0])
- stack.append(res)
- elif mname == 'slice':
- assert len(args) == 1
- assert isinstance(args[0], int)
- assert isinstance(obj, list)
- res = obj[args[0]:]
+
+ if isinstance(obj, _AVMClass_Object):
+ func = self.extract_function(obj.avm_class, mname)
+ res = func(args)
stack.append(res)
- elif mname == 'join':
- assert len(args) == 1
- assert isinstance(args[0], compat_str)
- assert isinstance(obj, list)
- res = args[0].join(obj)
+ 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)
- elif mname in avm_class.method_pyfunctions:
- stack.append(avm_class.method_pyfunctions[mname](args))
- else:
- raise NotImplementedError(
- 'Unsupported property %r on %r'
- % (mname, obj))
+ 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
obj = stack.pop()
mname = self.multinames[index]
- construct_method = self.extract_function(
- obj.avm_class, mname)
+ assert isinstance(obj, _AVMClass)
+
# We do not actually call the constructor for now;
# we just pretend it does nothing
- stack.append(obj)
+ stack.append(obj.make_object())
elif opcode == 79: # callpropvoid
index = u30()
mname = self.multinames[index]
elif opcode == 93: # findpropstrict
index = u30()
mname = self.multinames[index]
- res = self.extract_function(avm_class, mname)
- stack.append(res)
+ 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]
- res = avm_class.variables.get(mname)
+ 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]
- res = avm_class.variables.get(mname, None)
+ 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
obj = stack.pop()
assert isinstance(obj, list)
stack.append(len(obj))
+ elif isinstance(pname, compat_str): # Member access
+ obj = stack.pop()
+ assert isinstance(obj, (dict, _ScopeDict)), \
+ 'Accessing member on %r' % obj
+ stack.append(obj[pname])
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()
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
projects / youtube-dl / blobdiff