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mirror of synced 2024-11-27 23:50:47 +01:00

Implement decompressed kbinxml decoding

This commit is contained in:
Bottersnike 2022-06-18 09:59:31 +09:00 committed by Jennifer Taylor
parent 8ab1800ff4
commit 036bf1ce20

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@ -248,7 +248,7 @@ class BinaryDecoder:
A class capable of taking a binary blob and decoding it to a Node tree. A class capable of taking a binary blob and decoding it to a Node tree.
""" """
def __init__(self, data: bytes, encoding: str) -> None: def __init__(self, data: bytes, encoding: str, compressed: bool) -> None:
""" """
Initialize the object. Initialize the object.
@ -259,6 +259,7 @@ class BinaryDecoder:
""" """
self.stream = InputStream(data) self.stream = InputStream(data)
self.encoding = encoding self.encoding = encoding
self.compressed = compressed
self.executed = False self.executed = False
def __read_node_name(self) -> str: def __read_node_name(self) -> str:
@ -272,6 +273,31 @@ class BinaryDecoder:
length = self.stream.read_int() length = self.stream.read_int()
if length is None: if length is None:
raise BinaryEncodingException("Ran out of data when attempting to read node name length!") raise BinaryEncodingException("Ran out of data when attempting to read node name length!")
if not self.compressed:
if length < 0x40:
raise BinaryEncodingException("Node name length under decompressed minimum")
elif length < 0x80:
length -= 0x3f
else:
length_ex = self.stream.read_int()
if length_ex is None:
raise BinaryEncodingException("Ran out of data when attempting to read node name length!")
length = (length << 8) | length_ex
length -= 0x7fbf
if length > BinaryEncoding.NAME_MAX_DECOMPRESSED:
raise BinaryEncodingException("Node name length over decompressed limit")
name = self.stream.read_blob(length)
if name is None:
raise BinaryEncodingException("Ran out of data when attempting to read node name!")
return name.decode(self.encoding)
if length > BinaryEncoding.NAME_MAX_COMPRESSED:
raise BinaryEncodingException("Node name length over compressed limit")
binary_length = int(((length * 6) + 7) / 8) binary_length = int(((length * 6) + 7) / 8)
def int_to_bin(integer: int) -> str: def int_to_bin(integer: int) -> str:
@ -716,6 +742,9 @@ class BinaryEncoding:
DECOMPRESSED_WITH_DATA: Final[int] = 0x45 DECOMPRESSED_WITH_DATA: Final[int] = 0x45
DECOMPRESSED_WITHOUT_DATA: Final[int] = 0x46 DECOMPRESSED_WITHOUT_DATA: Final[int] = 0x46
NAME_MAX_COMPRESSED: Final[int] = 0x24
NAME_MAX_DECOMPRESSED: Final[int] = 0x1000
# The string values should match the constants in EAmuseProtocol. # The string values should match the constants in EAmuseProtocol.
# I have no better way to link these than to write this comment, # I have no better way to link these than to write this comment,
# as otherwise we would have a circular dependency. # as otherwise we would have a circular dependency.
@ -732,6 +761,7 @@ class BinaryEncoding:
Initialize the encoding object. Initialize the encoding object.
""" """
self.encoding: Optional[str] = None self.encoding: Optional[str] = None
self.compressed: bool = True
def __sanitize_encoding(self, enc: str) -> str: def __sanitize_encoding(self, enc: str) -> str:
""" """
@ -770,8 +800,13 @@ class BinaryEncoding:
return None return None
if ((~encoding_raw) & 0xFF) != encoding_swapped: if ((~encoding_raw) & 0xFF) != encoding_swapped:
return None return None
if contents not in [BinaryEncoding.COMPRESSED_WITH_DATA, BinaryEncoding.COMPRESSED_WITHOUT_DATA]:
# We don't support uncompressed data. self.compressed = contents in [
BinaryEncoding.COMPRESSED_WITH_DATA, BinaryEncoding.COMPRESSED_WITHOUT_DATA
]
if not self.compressed and contents not in [
BinaryEncoding.DECOMPRESSED_WITH_DATA, BinaryEncoding.DECOMPRESSED_WITHOUT_DATA
]:
return None return None
encoding = BinaryEncoding.ENCODINGS.get(encoding_raw) encoding = BinaryEncoding.ENCODINGS.get(encoding_raw)
@ -779,7 +814,9 @@ class BinaryEncoding:
if encoding is not None: if encoding is not None:
self.encoding = encoding self.encoding = encoding
try: try:
decoder = BinaryDecoder(data[4:], self.__sanitize_encoding(encoding)) decoder = BinaryDecoder(
data[4:], self.__sanitize_encoding(encoding), self.compressed
)
return decoder.get_tree() return decoder.get_tree()
except BinaryEncodingException: except BinaryEncodingException:
if skip_on_exceptions: if skip_on_exceptions: