def process(self, data):
dst = bytearray()
src = StructReader(data)
while not src.eof:
copy = src.read_byte()
for mask in (0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80):
if src.eof:
break
if not copy & mask:
dst.append(src.read_byte())
continue
elif not dst:
raise ValueError('copy requested against empty buffer')
with src.be:
match_len = src.read_integer(6) + _MATCH_MIN
match_pos = src.read_integer(10)
if not match_pos or match_pos > len(dst):
raise RuntimeError(F'invalid match offset at position {src.tell()}')
match_pos = len(dst) - match_pos
while match_len > 0:
match = dst[match_pos:match_pos + match_len]
dst.extend(match)
match_pos += len(match)
match_len -= len(match)
return dst
def __init__(self, reader: StructReader):
reader.bigendian = True
entry_start_offset = reader.tell()
self.size_of_entry = reader.i32()
self.offset = reader.i32()
self.size_of_compressed_data = reader.i32()
self.size_od_uncompressed_data = reader.i32()
self.is_compressed = bool(reader.read_byte())
entry_type = bytes(reader.read(1))
name_length = self.size_of_entry - reader.tell() + entry_start_offset
if name_length > 0x1000:
raise RuntimeError(
F'Refusing to process TOC entry with name of size {name_length}.'
)
name, *_ = bytes(reader.read(name_length)).partition(B'\0')
try:
name = name.decode('utf8', 'backslashreplace')
except Exception:
name = None
if not all(part.isprintable() for part in re.split('\\s*', name)):
raise RuntimeError(
'Refusing to process TOC entry with non-printable name.')
name = name or str(uuid.uuid4())
if entry_type == B'Z':
entry_type = B'z'
try:
self.type = PiType(entry_type)
except ValueError:
xtpyi.logger.error(F'unknown type {entry_type!r} in field {name}')
self.type = PiType.UNKNOWN
self.name = name
def __init__(self, reader: StructReader):
with StreamDetour(reader):
self.code = opc(reader.read_byte())
self.table: Optional[Dict[int, int]] = None
try:
fmt = self.OPC_ARGMAP[self.code]
except KeyError:
self.arguments = []
else:
self.arguments = list(reader.read_struct(fmt))
if self.code == opc.newarray:
self.arguments = [JvBaseType(reader.read_byte())]
elif self.code in self.OPC_CONSTPOOL:
try:
self.arguments[0] = self.pool[self.arguments[0] - 1]
except (AttributeError, IndexError):
pass
elif self.code == opc.lookupswitch:
reader.byte_align(blocksize=4)
default, npairs = reader.read_struct('LL')
pairs = reader.read_struct(F'{npairs*2}L')
self.table = dict(zip(*([iter(pairs)] * 2)))
self.table[None] = default
elif self.code == opc.tableswitch:
reader.byte_align(blocksize=4)
default, low, high = reader.read_struct('LLL')
assert low <= high
offsets = reader.read_struct(F'{high-low+1}L')
self.table = {k + low: offset for k, offset in enumerate(offsets)}
self.table[None] = default
elif self.code == opc.wide:
argop = opc(reader.get_byte())
self.arguments = (argop, reader.u16())
if argop == opc.iinc:
self.arguments += reader.i16(),
else:
assert argop in (
opc.iload, opc.istore,
opc.fload, opc.fstore,
opc.aload, opc.astore,
opc.lload, opc.lstore,
opc.dload, opc.dstore,
opc.ret)
offset = reader.tell()
self.raw = bytes(reader.read(offset - reader.tell()))
def test_bitreader_be(self):
data = 0b01010_10011101_0100100001_1111_0111101010000101010101010010010111100000101001010101100000001110010111110100111000_101
size, remainder = divmod(data.bit_length(), 8)
self.assertEqual(remainder, 7)
data = memoryview(data.to_bytes(size + 1, 'big'))
sr = StructReader(data)
with sr.be:
self.assertEqual(sr.read_bit(), 0)
self.assertEqual(sr.read_bit(), 1)
self.assertEqual(sr.read_bit(), 0)
self.assertEqual(sr.read_bit(), 1)
self.assertEqual(sr.read_bit(), 0)
self.assertEqual(sr.read_byte(), 0b10011101)
self.assertEqual(sr.read_integer(10), 0b100100001)
self.assertTrue(all(sr.read_flags(4)))
self.assertEqual(
sr.read_integer(82),
0b0111101010000101010101010010010111100000101001010101100000001110010111110100111000
)
self.assertRaises(EOF, sr.u16)
def test_bitreader_structured(self):
items = (
0b1100101, # noqa
-0x1337, # noqa
0xDEFACED, # noqa
0xC0CAC01A, # noqa
-0o1337, # noqa
2076.171875, # noqa
math.pi # noqa
)
data = struct.pack('<bhiLqfd', *items)
sr = StructReader(data)
self.assertEqual(sr.read_nibble(), 0b101)
self.assertRaises(sr.Unaligned, lambda: sr.read_exactly(2))
sr.seek(0)
self.assertEqual(sr.read_byte(), 0b1100101)
self.assertEqual(sr.i16(), -0x1337)
self.assertEqual(sr.i32(), 0xDEFACED)
self.assertEqual(sr.u32(), 0xC0CAC01A)
self.assertEqual(sr.i64(), -0o1337)
self.assertAlmostEqual(sr.read_struct('f', True), 2076.171875)
self.assertAlmostEqual(sr.read_struct('d', True), math.pi)
self.assertTrue(sr.eof)
class blz(Unit):
"""
BriefLZ compression and decompression. The compression algorithm uses a pure Python suffix tree
implementation: It requires a lot of time & memory.
"""
def _begin(self, data):
self._src = StructReader(memoryview(data))
self._dst = MemoryFile(bytearray())
return self
def _reset(self):
self._src.seek(0)
self._dst.seek(0)
self._dst.truncate()
return self
def _decompress(self):
(
signature,
version,
src_count,
src_crc32,
dst_count,
dst_crc32,
) = self._src.read_struct('>6L')
if signature != 0x626C7A1A:
raise ValueError(F'Invalid BriefLZ signature: {signature:08X}, should be 626C7A1A.')
if version > 10:
raise ValueError(F'Invalid version number {version}, should be less than 10.')
self.log_debug(F'signature: 0x{signature:08X} V{version}')
self.log_debug(F'src count: 0x{src_count:08X}')
self.log_debug(F'src crc32: 0x{src_crc32:08X}')
self.log_debug(F'dst count: 0x{dst_count:08X}')
self.log_debug(F'dst crc32: 0x{dst_crc32:08X}')
src = self._src.getbuffer()
src = src[24:24 + src_count]
if len(src) < src_count:
self.log_warn(F'Only {len(src)} bytes in buffer, but header annoucned a length of {src_count}.')
if src_crc32:
check = zlib.crc32(src)
if check != src_crc32:
self.log_warn(F'Invalid source data CRC {check:08X}, should be {src_crc32:08X}.')
dst = self._decompress_chunk(dst_count)
if not dst_crc32:
return dst
check = zlib.crc32(dst)
if check != dst_crc32:
self.log_warn(F'Invalid result data CRC {check:08X}, should be {dst_crc32:08X}.')
return dst
def _decompress_modded(self):
self._src.seekrel(8)
total_size = self._src.u64()
chunk_size = self._src.u64()
remaining = total_size
self.log_debug(F'total size: 0x{total_size:016X}')
self.log_debug(F'chunk size: 0x{chunk_size:016X}')
while remaining > chunk_size:
self._decompress_chunk(chunk_size)
remaining -= chunk_size
return self._decompress_chunk(remaining)
def _decompress_chunk(self, size=None):
bitcount = 0
bitstore = 0
decompressed = 1
def readbit():
nonlocal bitcount, bitstore
if not bitcount:
bitstore = int.from_bytes(self._src.read_exactly(2), 'little')
bitcount = 0xF
else:
bitcount = bitcount - 1
return (bitstore >> bitcount) & 1
def readint():
result = 2 + readbit()
while readbit():
result <<= 1
result += readbit()
return result
self._dst.write(self._src.read_exactly(1))
try:
while not size or decompressed < size:
if readbit():
length = readint() + 2
sector = readint() - 2
offset = self._src.read_byte() + 1
delta = offset + 0x100 * sector
available = self._dst.tell()
if delta not in range(available + 1):
raise RefineryPartialResult(
F'Requested rewind by 0x{delta:08X} bytes with only 0x{available:08X} bytes in output buffer.',
partial=self._dst.getvalue())
quotient, remainder = divmod(length, delta)
replay = memoryview(self._dst.getbuffer())
replay = bytes(replay[-delta:] if quotient else replay[-delta:length - delta])
replay = quotient * replay + replay[:remainder]
self._dst.write(replay)
decompressed += length
else:
self._dst.write(self._src.read_exactly(1))
decompressed += 1
except EOF as E:
raise RefineryPartialResult(str(E), partial=self._dst.getbuffer())
dst = self._dst.getbuffer()
if decompressed < size:
raise RefineryPartialResult(
F'Attempted to decompress {size} bytes, got only {len(dst)}.', dst)
if decompressed > size:
raise RuntimeError('Decompressed buffer contained more bytes than expected.')
return dst
def _compress(self):
from refinery.lib.suffixtree import SuffixTree
try:
self.log_info('computing suffix tree')
tree = SuffixTree(self._src.getbuffer())
except Exception:
raise
bitstore = 0 # The bit stream to be written
bitcount = 0 # The number of bits in the bit stream
buffer = MemoryFile(bytearray())
# Write empty header and first byte of source
self._dst.write(bytearray(24))
self._dst.write(self._src.read_exactly(1))
def writeint(n: int) -> None:
"""
Write an integer to the bit stream.
"""
nonlocal bitstore, bitcount
nbits = n.bit_length()
if nbits < 2:
raise ValueError
# The highest bit is implicitly assumed:
n ^= 1 << (nbits - 1)
remaining = nbits - 2
while remaining:
remaining -= 1
bitstore <<= 2
bitcount += 2
bitstore |= ((n >> remaining) & 3) | 1
bitstore <<= 2
bitcount += 2
bitstore |= (n & 1) << 1
src = self._src.getbuffer()
remaining = len(src) - 1
self.log_info('compressing data')
while True:
cursor = len(src) - remaining
rest = src[cursor:]
if bitcount >= 0x10:
block_count, bitcount = divmod(bitcount, 0x10)
info_channel = bitstore >> bitcount
bitstore = info_channel << bitcount ^ bitstore
# The decompressor will read bits from top to bottom, and each 16 bit block has to be
# little-endian encoded. The bit stream is encoded top to bottom bit in the bitstore
# variable, and by encoding it as a big endian integer, the stream is in the correct
# order. However, we need to swap adjacent bytes to achieve little endian encoding for
# each of the blocks:
info_channel = bytearray(info_channel.to_bytes(block_count * 2, 'big'))
for k in range(block_count):
k0 = 2 * k + 0
k1 = 2 * k + 1
info_channel[k0], info_channel[k1] = info_channel[k1], info_channel[k0]
info_channel = memoryview(info_channel)
data_channel = memoryview(buffer.getbuffer())
self._dst.write(info_channel[:2])
self._dst.write(data_channel[:-1])
self._dst.write(info_channel[2:])
data_channel = bytes(data_channel[-1:])
buffer.truncate(0)
store = buffer if bitcount else self._dst
store.write(data_channel)
if remaining + bitcount < 0x10:
buffer = buffer.getbuffer()
if rest or buffer:
bitstore <<= 0x10 - bitcount
self._dst.write(bitstore.to_bytes(2, 'little'))
self._dst.write(buffer)
self._dst.write(rest)
elif bitcount:
raise RuntimeError('Bitbuffer Overflow')
break
node = tree.root
length = 0
offset = 0
sector = None
while node.children and length < len(rest):
for child in node.children.values():
if tree.data[child.start] == rest[length]:
node = child
break
if node.start >= cursor:
break
offset = node.start - length
length = node.end + 1 - offset
length = min(remaining, length)
if length >= 4:
sector, offset = divmod(cursor - offset - 1, 0x100)
bitcount += 1
bitstore <<= 1
if sector is None:
buffer.write(rest[:1])
remaining -= 1
continue
bitstore |= 1
buffer.write(bytes((offset,)))
writeint(length - 2)
writeint(sector + 2)
remaining -= length
self._dst.seek(24)
dst = self._dst.peek()
self._dst.seek(0)
self._dst.write(struct.pack('>6L', 0x626C7A1A, 1, len(dst), zlib.crc32(dst), len(src), zlib.crc32(src)))
return self._dst.getbuffer()
def process(self, data):
self._begin(data)
partial = None
try:
return self._decompress()
except ValueError as error:
if isinstance(error, RefineryPartialResult):
partial = error
self.log_warn(F'Reverting to modified BriefLZ after decompression error: {error!s}')
self._reset()
try:
return self._decompress_modded()
except RefineryPartialResult:
raise
except Exception as error:
if not partial:
raise
raise partial from error
def reverse(self, data):
return self._begin(data)._compress()
def _decompress_xpress_huffman(self,
reader: StructReader,
writer: MemoryFile,
target: Optional[int] = None,
max_chunk_size: int = 0x10000) -> None:
limit = writer.tell()
if target is not None:
target += limit
while not reader.eof:
if reader.remaining_bytes < XPRESS_NUM_SYMBOLS // 2:
raise IndexError(
F'There are only {reader.remaining_bytes} bytes reamining in the input buffer,'
F' but at least {XPRESS_NUM_SYMBOLS//2} are required to read a Huffman table.'
)
table = bytearray(
reader.read_integer(4) for _ in range(XPRESS_NUM_SYMBOLS))
table = make_huffman_decode_table(table, XPRESS_TABLEBITS,
XPRESS_MAX_CODEWORD_LEN)
limit = limit + max_chunk_size
flags = BitBufferedReader(reader, 16)
while True:
position = writer.tell()
if position == target:
if reader.remaining_bytes:
self.log_info(
F'chunk decompressed with {reader.remaining_bytes} bytes remaining in input buffer'
)
return
if position >= limit:
if position > limit:
limit = position
self.log_info(
F'decompression of one chunk generated more than the limit of {max_chunk_size} bytes'
)
flags.collect()
break
try:
sym = flags.huffman_symbol(table, XPRESS_TABLEBITS,
XPRESS_MAX_CODEWORD_LEN)
except EOFError:
self.log_debug('end of file while reading huffman symbol')
break
if sym < XPRESS_NUM_CHARS:
writer.write_byte(sym)
continue
length = sym & 0xF
offsetlog = (sym >> 4) & 0xF
flags.collect()
if reader.eof:
break
offset = (1 << offsetlog) | flags.read(offsetlog)
if length == 0xF:
nudge = reader.read_byte()
if nudge < 0xFF:
length += nudge
else:
length = reader.u16() or reader.u32()
length += XPRESS_MIN_MATCH_LEN
writer.replay(offset, length)
def decompress_stream(self, data: ByteString, LZOv1: bool = False) -> bytearray:
"""
An implementation of LZO decompression. We use the article
"[LZO stream format as understood by Linux's LZO decompressor](https://www.kernel.org/doc/html/latest/staging/lzo.html)"
as a reference since no proper specification is available.
"""
def integer() -> int:
length = 0
while True:
byte = src.read_byte()
if byte:
return length + byte
length += 0xFF
if length > 0x100000:
raise LZOError('Too many zeros in integer encoding.')
def literal(count):
dst.write(src.read_bytes(count))
def copy(distance: int, length: int):
if distance > len(dst):
raise LZOError(F'Distance {distance} > bufsize {len(dst)}')
buffer = dst.getbuffer()
if distance > length:
start = len(buffer) - distance
end = start + length
dst.write(buffer[start:end])
else:
block = buffer[-distance:]
while len(block) < length:
block += block[:length - len(block)]
if len(block) > length:
block[length:] = ()
dst.write(block)
src = StructReader(memoryview(data))
dst = MemoryFile()
state = 0
first = src.read_byte()
if first == 0x10:
raise LZOError('Invalid first stream byte 0x10.')
elif first <= 0x12:
src.seekrel(-1)
elif first <= 0x15:
state = first - 0x11
literal(state)
else:
state = 4
literal(first - 0x11)
while True:
instruction = src.read_byte()
if instruction < 0x10:
if state == 0:
length = instruction or integer() + 15
state = length + 3
if state < 4:
raise LZOError('Literal encoding is too short.')
else:
state = instruction & 0b0011
D = (instruction & 0b1100) >> 2
H = src.read_byte()
distance = (H << 2) + D + 1
if state >= 4:
distance += 0x800
length = 3
else:
length = 2
copy(distance, length)
elif instruction < 0x20:
L = instruction & 0b0111
H = instruction & 0b1000
length = L or integer() + 7
argument = src.u16()
state = argument & 3
distance = (H << 11) + (argument >> 2)
if not distance:
return dst.getbuffer()
if LZOv1 and distance & 0x803F == 0x803F and length in range(261, 265):
raise LZOError('Compressed data contains sequence that is banned in LZOv1.')
if LZOv1 and distance == 0xBFFF:
X = src.read_byte()
count = ((X << 3) | L) + 4
self.log_debug(F'Writing run of {X} zero bytes according to LZOv1.')
dst.write(B'\0' * count)
else:
copy(distance + 0x4000, length + 2)
elif instruction < 0x40:
L = instruction & 0b11111
length = L or integer() + 31
argument = src.u16()
state = argument & 3
distance = (argument >> 2) + 1
copy(distance, length + 2)
else:
if instruction < 0x80:
length = 3 + ((instruction >> 5) & 1)
else:
length = 5 + ((instruction >> 5) & 3)
H = src.read_byte()
D = (instruction & 0b11100) >> 2
state = instruction & 3
distance = (H << 3) + D + 1
copy(distance, length)
if state:
literal(state)
def __init__(self, reader: StructReader):
self.kind = JvMethodHandleRefKind(reader.read_byte())
self.reference = reader.u16()
