projects / yt-dlp.git / blame
| Commit | Line | Data |
|---|---|---|
| 54256267 PH |
1 | from __future__ import unicode_literals |
| 2 | ||
| 3 | import collections | |
| 4 | import io | |
| 5 | import struct | |
| 6 | import zlib | |
| 7 | ||
| 8 | from .utils import ExtractorError | |
| 9 | ||
| 10 | ||
| 11 | def _extract_tags(content): | |
| 12 | pos = 0 | |
| 13 | while pos < len(content): | |
| 14 | header16 = struct.unpack('<H', content[pos:pos + 2])[0] | |
| 15 | pos += 2 | |
| 16 | tag_code = header16 >> 6 | |
| 17 | tag_len = header16 & 0x3f | |
| 18 | if tag_len == 0x3f: | |
| 19 | tag_len = struct.unpack('<I', content[pos:pos + 4])[0] | |
| 20 | pos += 4 | |
| 21 | assert pos + tag_len <= len(content) | |
| 22 | yield (tag_code, content[pos:pos + tag_len]) | |
| 23 | pos += tag_len | |
| 24 | ||
| 25 | ||
| 26 | class _AVMClass_Object(object): | |
| 27 | def __init__(self, avm_class): | |
| 28 | self.avm_class = avm_class | |
| 29 | ||
| 30 | def __repr__(self): | |
| 31 | return '%s#%x' % (self.avm_class.name, id(self)) | |
| 32 | ||
| 33 | ||
| 34 | class _AVMClass(object): | |
| 35 | def __init__(self, name_idx, name): | |
| 36 | self.name_idx = name_idx | |
| 37 | self.name = name | |
| 38 | self.method_names = {} | |
| 39 | self.method_idxs = {} | |
| 40 | self.methods = {} | |
| 41 | self.method_pyfunctions = {} | |
| 42 | self.variables = {} | |
| 43 | ||
| 44 | def make_object(self): | |
| 45 | return _AVMClass_Object(self) | |
| 46 | ||
| 47 | ||
| 48 | def _read_int(reader): | |
| 49 | res = 0 | |
| 50 | shift = 0 | |
| 51 | for _ in range(5): | |
| 52 | buf = reader.read(1) | |
| 53 | assert len(buf) == 1 | |
| 54 | b = struct.unpack('<B', buf)[0] | |
| 55 | res = res | ((b & 0x7f) << shift) | |
| 56 | if b & 0x80 == 0: | |
| 57 | break | |
| 58 | shift += 7 | |
| 59 | return res | |
| 60 | ||
| 61 | ||
| 62 | def _u30(reader): | |
| 63 | res = _read_int(reader) | |
| 64 | assert res & 0xf0000000 == 0 | |
| 65 | return res | |
| 66 | u32 = _read_int | |
| 67 | ||
| 68 | ||
| 69 | def _s32(reader): | |
| 70 | v = _read_int(reader) | |
| 71 | if v & 0x80000000 != 0: | |
| 72 | v = - ((v ^ 0xffffffff) + 1) | |
| 73 | return v | |
| 74 | ||
| 75 | ||
| 76 | def _s24(reader): | |
| 77 | bs = reader.read(3) | |
| 78 | assert len(bs) == 3 | |
| 79 | first_byte = b'\xff' if (ord(bs[0:1]) >= 0x80) else b'\x00' | |
| 80 | return struct.unpack('!i', first_byte + bs) | |
| 81 | ||
| 82 | ||
| 83 | def _read_string(reader): | |
| 84 | slen = _u30(reader) | |
| 85 | resb = reader.read(slen) | |
| 86 | assert len(resb) == slen | |
| 87 | return resb.decode('utf-8') | |
| 88 | ||
| 89 | ||
| 90 | def _read_bytes(count, reader): | |
| 91 | if reader is None: | |
| 92 | reader = code_reader | |
| 93 | resb = reader.read(count) | |
| 94 | assert len(resb) == count | |
| 95 | return resb | |
| 96 | ||
| 97 | ||
| 98 | def _read_byte(reader): | |
| 99 | resb = _read_bytes(1, reader=reader) | |
| 100 | res = struct.unpack('<B', resb)[0] | |
| 101 | return res | |
| 102 | ||
| 103 | ||
| 104 | class SWFInterpreter(object): | |
| 105 | def __init__(self, file_contents): | |
| 106 | if file_contents[1:3] != b'WS': | |
| 107 | raise ExtractorError( | |
| 108 | 'Not an SWF file; header is %r' % file_contents[:3]) | |
| 109 | if file_contents[:1] == b'C': | |
| 110 | content = zlib.decompress(file_contents[8:]) | |
| 111 | else: | |
| 112 | raise NotImplementedError( | |
| 113 | 'Unsupported compression format %r' % | |
| 114 | file_contents[:1]) | |
| 115 | ||
| 116 | code_tag = next(tag | |
| 117 | for tag_code, tag in _extract_tags(content) | |
| 118 | if tag_code == 82) | |
| 119 | p = code_tag.index(b'\0', 4) + 1 | |
| 120 | code_reader = io.BytesIO(code_tag[p:]) | |
| 121 | ||
| 122 | # Parse ABC (AVM2 ByteCode) | |
| 123 | ||
| 124 | # Define a couple convenience methods | |
| 125 | u30 = lambda *args: _u30(*args, reader=code_reader) | |
| 126 | s32 = lambda *args: _s32(*args, reader=code_reader) | |
| 127 | u32 = lambda *args: _u32(*args, reader=code_reader) | |
| 128 | read_bytes = lambda *args: _read_bytes(*args, reader=code_reader) | |
| 129 | read_byte = lambda *args: _read_byte(*args, reader=code_reader) | |
| 130 | ||
| 131 | # minor_version + major_version | |
| 132 | read_bytes(2 + 2) | |
| 133 | ||
| 134 | # Constant pool | |
| 135 | int_count = u30() | |
| 136 | for _c in range(1, int_count): | |
| 137 | s32() | |
| 138 | uint_count = u30() | |
| 139 | for _c in range(1, uint_count): | |
| 140 | u32() | |
| 141 | double_count = u30() | |
| 142 | read_bytes((double_count - 1) * 8) | |
| 143 | string_count = u30() | |
| 144 | constant_strings = [''] | |
| 145 | for _c in range(1, string_count): | |
| 146 | s = _read_string(code_reader) | |
| 147 | constant_strings.append(s) | |
| 148 | namespace_count = u30() | |
| 149 | for _c in range(1, namespace_count): | |
| 150 | read_bytes(1) # kind | |
| 151 | u30() # name | |
| 152 | ns_set_count = u30() | |
| 153 | for _c in range(1, ns_set_count): | |
| 154 | count = u30() | |
| 155 | for _c2 in range(count): | |
| 156 | u30() | |
| 157 | multiname_count = u30() | |
| 158 | MULTINAME_SIZES = { | |
| 159 | 0x07: 2, # QName | |
| 160 | 0x0d: 2, # QNameA | |
| 161 | 0x0f: 1, # RTQName | |
| 162 | 0x10: 1, # RTQNameA | |
| 163 | 0x11: 0, # RTQNameL | |
| 164 | 0x12: 0, # RTQNameLA | |
| 165 | 0x09: 2, # Multiname | |
| 166 | 0x0e: 2, # MultinameA | |
| 167 | 0x1b: 1, # MultinameL | |
| 168 | 0x1c: 1, # MultinameLA | |
| 169 | } | |
| 170 | self.multinames = [''] | |
| 171 | for _c in range(1, multiname_count): | |
| 172 | kind = u30() | |
| 173 | assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind | |
| 174 | if kind == 0x07: | |
| 175 | u30() # namespace_idx | |
| 176 | name_idx = u30() | |
| 177 | self.multinames.append(constant_strings[name_idx]) | |
| 178 | else: | |
| 179 | self.multinames.append('[MULTINAME kind: %d]' % kind) | |
| 180 | for _c2 in range(MULTINAME_SIZES[kind]): | |
| 181 | u30() | |
| 182 | ||
| 183 | # Methods | |
| 184 | method_count = u30() | |
| 185 | MethodInfo = collections.namedtuple( | |
| 186 | 'MethodInfo', | |
| 187 | ['NEED_ARGUMENTS', 'NEED_REST']) | |
| 188 | method_infos = [] | |
| 189 | for method_id in range(method_count): | |
| 190 | param_count = u30() | |
| 191 | u30() # return type | |
| 192 | for _ in range(param_count): | |
| 193 | u30() # param type | |
| 194 | u30() # name index (always 0 for youtube) | |
| 195 | flags = read_byte() | |
| 196 | if flags & 0x08 != 0: | |
| 197 | # Options present | |
| 198 | option_count = u30() | |
| 199 | for c in range(option_count): | |
| 200 | u30() # val | |
| 201 | read_bytes(1) # kind | |
| 202 | if flags & 0x80 != 0: | |
| 203 | # Param names present | |
| 204 | for _ in range(param_count): | |
| 205 | u30() # param name | |
| 206 | mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0) | |
| 207 | method_infos.append(mi) | |
| 208 | ||
| 209 | # Metadata | |
| 210 | metadata_count = u30() | |
| 211 | for _c in range(metadata_count): | |
| 212 | u30() # name | |
| 213 | item_count = u30() | |
| 214 | for _c2 in range(item_count): | |
| 215 | u30() # key | |
| 216 | u30() # value | |
| 217 | ||
| 218 | def parse_traits_info(): | |
| 219 | trait_name_idx = u30() | |
| 220 | kind_full = read_byte() | |
| 221 | kind = kind_full & 0x0f | |
| 222 | attrs = kind_full >> 4 | |
| 223 | methods = {} | |
| 224 | if kind in [0x00, 0x06]: # Slot or Const | |
| 225 | u30() # Slot id | |
| 226 | u30() # type_name_idx | |
| 227 | vindex = u30() | |
| 228 | if vindex != 0: | |
| 229 | read_byte() # vkind | |
| 230 | elif kind in [0x01, 0x02, 0x03]: # Method / Getter / Setter | |
| 231 | u30() # disp_id | |
| 232 | method_idx = u30() | |
| 233 | methods[self.multinames[trait_name_idx]] = method_idx | |
| 234 | elif kind == 0x04: # Class | |
| 235 | u30() # slot_id | |
| 236 | u30() # classi | |
| 237 | elif kind == 0x05: # Function | |
| 238 | u30() # slot_id | |
| 239 | function_idx = u30() | |
| 240 | methods[function_idx] = self.multinames[trait_name_idx] | |
| 241 | else: | |
| 242 | raise ExtractorError('Unsupported trait kind %d' % kind) | |
| 243 | ||
| 244 | if attrs & 0x4 != 0: # Metadata present | |
| 245 | metadata_count = u30() | |
| 246 | for _c3 in range(metadata_count): | |
| 247 | u30() # metadata index | |
| 248 | ||
| 249 | return methods | |
| 250 | ||
| 251 | # Classes | |
| 252 | class_count = u30() | |
| 253 | classes = [] | |
| 254 | for class_id in range(class_count): | |
| 255 | name_idx = u30() | |
| 256 | classes.append(_AVMClass(name_idx, self.multinames[name_idx])) | |
| 257 | u30() # super_name idx | |
| 258 | flags = read_byte() | |
| 259 | if flags & 0x08 != 0: # Protected namespace is present | |
| 260 | u30() # protected_ns_idx | |
| 261 | intrf_count = u30() | |
| 262 | for _c2 in range(intrf_count): | |
| 263 | u30() | |
| 264 | u30() # iinit | |
| 265 | trait_count = u30() | |
| 266 | for _c2 in range(trait_count): | |
| 267 | parse_traits_info() | |
| 268 | assert len(classes) == class_count | |
| 269 | self._classes_by_name = dict((c.name, c) for c in classes) | |
| 270 | ||
| 271 | for avm_class in classes: | |
| 272 | u30() # cinit | |
| 273 | trait_count = u30() | |
| 274 | for _c2 in range(trait_count): | |
| 275 | trait_methods = parse_traits_info() | |
| 276 | avm_class.method_names.update(trait_methods.items()) | |
| 277 | avm_class.method_idxs.update(dict( | |
| 278 | (idx, name) | |
| 279 | for name, idx in trait_methods.items())) | |
| 280 | ||
| 281 | # Scripts | |
| 282 | script_count = u30() | |
| 283 | for _c in range(script_count): | |
| 284 | u30() # init | |
| 285 | trait_count = u30() | |
| 286 | for _c2 in range(trait_count): | |
| 287 | parse_traits_info() | |
| 288 | ||
| 289 | # Method bodies | |
| 290 | method_body_count = u30() | |
| 291 | Method = collections.namedtuple('Method', ['code', 'local_count']) | |
| 292 | for _c in range(method_body_count): | |
| 293 | method_idx = u30() | |
| 294 | u30() # max_stack | |
| 295 | local_count = u30() | |
| 296 | u30() # init_scope_depth | |
| 297 | u30() # max_scope_depth | |
| 298 | code_length = u30() | |
| 299 | code = read_bytes(code_length) | |
| 300 | for avm_class in classes: | |
| 301 | if method_idx in avm_class.method_idxs: | |
| 302 | m = Method(code, local_count) | |
| 303 | avm_class.methods[avm_class.method_idxs[method_idx]] = m | |
| 304 | exception_count = u30() | |
| 305 | for _c2 in range(exception_count): | |
| 306 | u30() # from | |
| 307 | u30() # to | |
| 308 | u30() # target | |
| 309 | u30() # exc_type | |
| 310 | u30() # var_name | |
| 311 | trait_count = u30() | |
| 312 | for _c2 in range(trait_count): | |
| 313 | parse_traits_info() | |
| 314 | ||
| 315 | assert p + code_reader.tell() == len(code_tag) | |
| 316 | ||
| 317 | def extract_class(self, class_name): | |
| 318 | try: | |
| 319 | return self._classes_by_name[class_name] | |
| 320 | except KeyError: | |
| 321 | raise ExtractorError('Class %r not found' % class_name) | |
| 322 | ||
| 323 | def extract_function(self, avm_class, func_name): | |
| 324 | if func_name in avm_class.method_pyfunctions: | |
| 325 | return avm_class.method_pyfunctions[func_name] | |
| 326 | if func_name in self._classes_by_name: | |
| 327 | return self._classes_by_name[func_name].make_object() | |
| 328 | if func_name not in avm_class.methods: | |
| 329 | raise ExtractorError('Cannot find function %r' % func_name) | |
| 330 | m = avm_class.methods[func_name] | |
| 331 | ||
| 332 | def resfunc(args): | |
| 333 | # Helper functions | |
| 334 | coder = io.BytesIO(m.code) | |
| 335 | s24 = lambda: _s24(coder) | |
| 336 | u30 = lambda: _u30(coder) | |
| 337 | ||
| 338 | print('Invoking %s.%s(%r)' % (avm_class.name, func_name, tuple(args))) | |
| 339 | registers = ['(this)'] + list(args) + [None] * m.local_count | |
| 340 | stack = [] | |
| 341 | while True: | |
| 342 | opcode = _read_byte(coder) | |
| 343 | print('opcode: %r, stack(%d): %r' % (opcode, len(stack), stack)) | |
| 344 | if opcode == 17: # iftrue | |
| 345 | offset = s24() | |
| 346 | value = stack.pop() | |
| 347 | if value: | |
| 348 | coder.seek(coder.tell() + offset) | |
| 349 | elif opcode == 36: # pushbyte | |
| 350 | v = _read_byte(coder) | |
| 351 | stack.append(v) | |
| 352 | elif opcode == 44: # pushstring | |
| 353 | idx = u30() | |
| 354 | stack.append(constant_strings[idx]) | |
| 355 | elif opcode == 48: # pushscope | |
| 356 | # We don't implement the scope register, so we'll just | |
| 357 | # ignore the popped value | |
| 358 | new_scope = stack.pop() | |
| 359 | elif opcode == 70: # callproperty | |
| 360 | index = u30() | |
| 361 | mname = self.multinames[index] | |
| 362 | arg_count = u30() | |
| 363 | args = list(reversed( | |
| 364 | [stack.pop() for _ in range(arg_count)])) | |
| 365 | obj = stack.pop() | |
| 366 | if mname == 'split': | |
| 367 | assert len(args) == 1 | |
| 368 | assert isinstance(args[0], compat_str) | |
| 369 | assert isinstance(obj, compat_str) | |
| 370 | if args[0] == '': | |
| 371 | res = list(obj) | |
| 372 | else: | |
| 373 | res = obj.split(args[0]) | |
| 374 | stack.append(res) | |
| 375 | elif mname == 'slice': | |
| 376 | assert len(args) == 1 | |
| 377 | assert isinstance(args[0], int) | |
| 378 | assert isinstance(obj, list) | |
| 379 | res = obj[args[0]:] | |
| 380 | stack.append(res) | |
| 381 | elif mname == 'join': | |
| 382 | assert len(args) == 1 | |
| 383 | assert isinstance(args[0], compat_str) | |
| 384 | assert isinstance(obj, list) | |
| 385 | res = args[0].join(obj) | |
| 386 | stack.append(res) | |
| 387 | elif mname in avm_class.method_pyfunctions: | |
| 388 | stack.append(avm_class.method_pyfunctions[mname](args)) | |
| 389 | else: | |
| 390 | raise NotImplementedError( | |
| 391 | 'Unsupported property %r on %r' | |
| 392 | % (mname, obj)) | |
| 393 | elif opcode == 72: # returnvalue | |
| 394 | res = stack.pop() | |
| 395 | return res | |
| 396 | elif opcode == 74: # constructproperty | |
| 397 | index = u30() | |
| 398 | arg_count = u30() | |
| 399 | args = list(reversed( | |
| 400 | [stack.pop() for _ in range(arg_count)])) | |
| 401 | obj = stack.pop() | |
| 402 | ||
| 403 | mname = self.multinames[index] | |
| 404 | construct_method = self.extract_function( | |
| 405 | obj.avm_class, mname) | |
| 406 | # We do not actually call the constructor for now; | |
| 407 | # we just pretend it does nothing | |
| 408 | stack.append(obj) | |
| 409 | elif opcode == 79: # callpropvoid | |
| 410 | index = u30() | |
| 411 | mname = self.multinames[index] | |
| 412 | arg_count = u30() | |
| 413 | args = list(reversed( | |
| 414 | [stack.pop() for _ in range(arg_count)])) | |
| 415 | obj = stack.pop() | |
| 416 | if mname == 'reverse': | |
| 417 | assert isinstance(obj, list) | |
| 418 | obj.reverse() | |
| 419 | else: | |
| 420 | raise NotImplementedError( | |
| 421 | 'Unsupported (void) property %r on %r' | |
| 422 | % (mname, obj)) | |
| 423 | elif opcode == 86: # newarray | |
| 424 | arg_count = u30() | |
| 425 | arr = [] | |
| 426 | for i in range(arg_count): | |
| 427 | arr.append(stack.pop()) | |
| 428 | arr = arr[::-1] | |
| 429 | stack.append(arr) | |
| 430 | elif opcode == 93: # findpropstrict | |
| 431 | index = u30() | |
| 432 | mname = self.multinames[index] | |
| 433 | res = self.extract_function(avm_class, mname) | |
| 434 | stack.append(res) | |
| 435 | elif opcode == 94: # findproperty | |
| 436 | index = u30() | |
| 437 | mname = self.multinames[index] | |
| 438 | res = avm_class.variables.get(mname) | |
| 439 | stack.append(res) | |
| 440 | elif opcode == 96: # getlex | |
| 441 | index = u30() | |
| 442 | mname = self.multinames[index] | |
| 443 | res = avm_class.variables.get(mname, None) | |
| 444 | stack.append(res) | |
| 445 | elif opcode == 97: # setproperty | |
| 446 | index = u30() | |
| 447 | value = stack.pop() | |
| 448 | idx = self.multinames[index] | |
| 449 | obj = stack.pop() | |
| 450 | obj[idx] = value | |
| 451 | elif opcode == 98: # getlocal | |
| 452 | index = u30() | |
| 453 | stack.append(registers[index]) | |
| 454 | elif opcode == 99: # setlocal | |
| 455 | index = u30() | |
| 456 | value = stack.pop() | |
| 457 | registers[index] = value | |
| 458 | elif opcode == 102: # getproperty | |
| 459 | index = u30() | |
| 460 | pname = self.multinames[index] | |
| 461 | if pname == 'length': | |
| 462 | obj = stack.pop() | |
| 463 | assert isinstance(obj, list) | |
| 464 | stack.append(len(obj)) | |
| 465 | else: # Assume attribute access | |
| 466 | idx = stack.pop() | |
| 467 | assert isinstance(idx, int) | |
| 468 | obj = stack.pop() | |
| 469 | assert isinstance(obj, list) | |
| 470 | stack.append(obj[idx]) | |
| 471 | elif opcode == 128: # coerce | |
| 472 | u30() | |
| 473 | elif opcode == 133: # coerce_s | |
| 474 | assert isinstance(stack[-1], (type(None), compat_str)) | |
| 475 | elif opcode == 164: # modulo | |
| 476 | value2 = stack.pop() | |
| 477 | value1 = stack.pop() | |
| 478 | res = value1 % value2 | |
| 479 | stack.append(res) | |
| 480 | elif opcode == 175: # greaterequals | |
| 481 | value2 = stack.pop() | |
| 482 | value1 = stack.pop() | |
| 483 | result = value1 >= value2 | |
| 484 | stack.append(result) | |
| 485 | elif opcode == 208: # getlocal_0 | |
| 486 | stack.append(registers[0]) | |
| 487 | elif opcode == 209: # getlocal_1 | |
| 488 | stack.append(registers[1]) | |
| 489 | elif opcode == 210: # getlocal_2 | |
| 490 | stack.append(registers[2]) | |
| 491 | elif opcode == 211: # getlocal_3 | |
| 492 | stack.append(registers[3]) | |
| 493 | elif opcode == 214: # setlocal_2 | |
| 494 | registers[2] = stack.pop() | |
| 495 | elif opcode == 215: # setlocal_3 | |
| 496 | registers[3] = stack.pop() | |
| 497 | else: | |
| 498 | raise NotImplementedError( | |
| 499 | 'Unsupported opcode %d' % opcode) | |
| 500 | ||
| 501 | avm_class.method_pyfunctions[func_name] = resfunc | |
| 502 | return resfunc | |
| 503 |