Module refinery.lib.thirdparty.acefile
Read/test/extract ACE 1.0 and 2.0 archives in pure python.
This single-file, pure python 3, no-dependencies implementation is intended to be used as a library, but also provides a stand-alone unace utility. As mostly pure-python implementation, it is significantly slower than native implementations, but more robust against vulnerabilities.
This implementation supports up to version 2.0 of the ACE archive format, including the EXE, DELTA, PIC and SOUND modes of ACE 2.0, password protected archives and multi-volume archives. It does not support writing to archives. It is an implementation from scratch, based on the 1998 document titled "Technical information of the archiver ACE v1.2" by Marcel Lemke, using unace 2.5 and WinAce 2.69 by Marcel Lemke as reference implementations.
For more information, API documentation, source code, packages and release notifications, refer to:
- https://www.roe.ch/acefile
- https://apidoc.roe.ch/acefile
- https://github.com/droe/acefile
- https://pypi.python.org/pypi/acefile
- https://twitter.com/droethlisberger
Expand source code Browse git
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# acefile - read/test/extract ACE 1.0 and 2.0 archives in pure python
# Copyright (C) 2017-2019, Daniel Roethlisberger <daniel@roe.ch>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions, and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# NOTE: The ACE archive format and ACE compression and decompression
# algorithms have been designed by Marcel Lemke. The above copyright
# notice and license does not constitute a claim of intellectual property
# over ACE technology beyond the copyright of this python implementation.
"""
Read/test/extract ACE 1.0 and 2.0 archives in pure python.
This single-file, pure python 3, no-dependencies implementation is intended
to be used as a library, but also provides a stand-alone unace utility.
As mostly pure-python implementation, it is significantly slower than
native implementations, but more robust against vulnerabilities.
This implementation supports up to version 2.0 of the ACE archive format,
including the EXE, DELTA, PIC and SOUND modes of ACE 2.0, password protected
archives and multi-volume archives. It does not support writing to archives.
It is an implementation from scratch, based on the 1998 document titled
"Technical information of the archiver ACE v1.2" by Marcel Lemke, using
unace 2.5 and WinAce 2.69 by Marcel Lemke as reference implementations.
For more information, API documentation, source code, packages and release
notifications, refer to:
- https://www.roe.ch/acefile
- https://apidoc.roe.ch/acefile
- https://github.com/droe/acefile
- https://pypi.python.org/pypi/acefile
- https://twitter.com/droethlisberger
"""
__version__ = '0.6.12'
__author__ = 'Daniel Roethlisberger'
__email__ = 'daniel@roe.ch'
__copyright__ = 'Copyright 2017-2019, Daniel Roethlisberger'
__credits__ = ['Marcel Lemke']
__license__ = 'BSD'
__url__ = 'https://www.roe.ch/acefile'
import array
import builtins
import ctypes
import datetime
import io
import math
import os
import platform
import re
import stat
import struct
import sys
import zlib
try:
import acebitstream
except:
acebitstream = None
# Very basic debugging facility; if set to True, exceptions raised during
# testing of archives will be raised and a minimal set of state information
# will be printed to stderr.
DEBUG = False
# Arbitrarily chosen buffer size to use for buffered file operations that
# have no obvious natural block size.
FILE_BLOCKSIZE = 131072
assert FILE_BLOCKSIZE % 4 == 0
if platform.system() == 'Windows':
# BOOL WINAPI SetFileAttributes(
# _In_ LPCTSTR lpFileName,
# _In_ DWORD dwFileAttributes
# );
try:
SetFileAttributes = ctypes.windll.kernel32.SetFileAttributesW
except:
SetFileAttributes = None
# BOOL WINAPI SetFileSecurity(
# _In_ LPCTSTR lpFileName,
# _In_ SECURITY_INFORMATION SecurityInformation,
# _In_ PSECURITY_DESCRIPTOR pSecurityDescriptor
# );
try:
SetFileSecurity = ctypes.windll.advapi32.SetFileSecurityW
except:
SetFileSecurity = None
else:
SetFileAttributes = None
SetFileSecurity = None
def eprint(*args, **kwargs):
"""
Print to stderr.
"""
print(*args, file=sys.stderr, **kwargs)
# haklib.dt
def _dt_fromdos(dosdt):
"""
Convert DOS format 32bit timestamp to datetime object.
Timestamps with illegal values out of the allowed range are ignored and a
datetime object representing 1980-01-01 00:00:00 is returned instead.
https://msdn.microsoft.com/en-us/library/9kkf9tah.aspx
>>> _dt_fromdos(0x4a5c48fd)
datetime.datetime(2017, 2, 28, 9, 7, 58)
>>> _dt_fromdos(0)
datetime.datetime(1980, 1, 1, 0, 0)
>>> _dt_fromdos(-1)
datetime.datetime(1980, 1, 1, 0, 0)
"""
try:
return datetime.datetime(
((dosdt >> 25) & 0x7F) + 1980,
(dosdt >> 21) & 0x0F,
(dosdt >> 16) & 0x1F,
(dosdt >> 11) & 0x1F,
(dosdt >> 5) & 0x3F,
((dosdt ) & 0x1F) * 2)
except ValueError:
return datetime.datetime(1980, 1, 1, 0, 0, 0)
# haklib.c
def c_div(q, d):
"""
Arbitrary signed integer division with c behaviour.
>>> (c_div(10, 3), c_div(-10, -3), c_div(-10, 3), c_div(10, -3))
(3, 3, -3, -3)
>>> c_div(-11, 0)
Traceback (most recent call last):
...
ZeroDivisionError
"""
s = int(math.copysign(1, q) * math.copysign(1, d))
return s * int(abs(q) / abs(d))
def c_schar(i):
"""
Convert arbitrary integer to c signed char type range as if casted in c.
>>> c_schar(0x12345678)
120
>>> (c_schar(-128), c_schar(-129), c_schar(127), c_schar(128))
(-128, 127, 127, -128)
"""
return ((i + 128) % 256) - 128
def c_uchar(i):
"""
Convert arbitrary integer to c unsigned char type range as if casted in c.
>>> c_uchar(0x12345678)
120
>>> (c_uchar(-123), c_uchar(-1), c_uchar(255), c_uchar(256))
(133, 255, 255, 0)
"""
return i & 0xFF
def c_rot32(i, n):
"""
Rotate *i* left by *n* bits within the uint32 value range.
>>> c_rot32(0xF0000000, 4)
15
>>> c_rot32(0xF0, -4)
15
"""
if n < 0:
n = 32 + n
return (((i << n) & 0xFFFFFFFF) | (i >> (32 - n)))
def c_add32(a, b):
"""
Add *a* and *b* within the uint32 value range.
>>> c_add32(0xFFFFFFFF, 1)
0
>>> c_add32(0xFFFFFFFF, 0xFFFFFFFF)
4294967294
"""
return (a + b) & 0xFFFFFFFF
def c_sum32(*args):
"""
Add all elements of *args* within the uint32 value range.
>>> c_sum32(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF)
4294967293
"""
return sum(args) & 0xFFFFFFFF
def asciibox(msg, title=None, minwidth=None):
"""
Returns message string *msg* wrapped in a plain ASCII box.
If *title* is given, add *title* in the top horizontal bar.
Lines will be padded to the longest out of *minwidth* characters, the
length of the longest line, or the length of the title plus six.
Caller is responsible for ensuring a sensible line length in *msg*.
"""
out = []
lines = msg.splitlines()
width = 0
for line in lines:
width = max(width, len(line))
if minwidth != None:
width = max(width, minwidth)
if title != None:
width = max(width, len(title) + 6)
ftr = "+" + ("-" * (width + 2)) + "+"
if title != None:
hdr = ("+--[ %s ]--" % title) + ("-" * (width - 6 - len(title))) + "+"
else:
hdr = ftr
fmt = "| %%-%is |" % width
out.append(hdr)
for line in msg.splitlines():
out.append(fmt % line)
out.append(ftr)
return '\n'.join(out)
class FileSegmentIO:
"""
Seekable file-like object that wraps and reads from seekable file-like
object and fakes EOF when a read would extend beyond a defined boundary.
>>> FileSegmentIO(io.BytesIO(b'0123456789'), 3, 4).read()
b'3456'
"""
def __init__(self, f, base, size):
assert f.seekable()
self.__file = f
self.__base = base
self.__eof = base + size
self.__file.seek(self.__base, 0)
def seekable(self):
return True
def _tell(self):
"""
Returns the current absolute position in the file and asserts that it
lies within the defined file segment.
"""
pos = self.__file.tell()
assert pos >= self.__base and pos <= self.__eof
return pos
def tell(self):
return self._tell() - self.__base
def seek(self, offset, whence=0):
if whence == 0:
newpos = self.__base + offset
elif whence == 1:
newpos = self._tell() + offset
elif whence == 2:
newpos = self.__eof + offset
assert newpos >= self.__base and newpos <= self.__eof
self.__file.seek(newpos, 0)
def read(self, n=None):
pos = self._tell()
if n == None:
amount = self.__eof - pos
else:
amount = min(n, self.__eof - pos)
if amount == 0:
return b''
return self.__file.read(amount)
class MultipleFilesIO:
"""
Seekable file-like object that wraps and reads from multiple
seekable lower-level file-like objects.
>>> MultipleFilesIO((io.BytesIO(b'01234'), io.BytesIO(b'56789'))).read()
b'0123456789'
"""
def __init__(self, files):
assert len(files) > 0
self.__files = files
self.__sizes = []
for f in files:
f.seek(0, 2)
self.__sizes.append(f.tell())
self.__files[0].seek(0)
self.__idx = 0
self.__pos = 0
self.__eof = sum(self.__sizes)
def seekable():
return True
def tell(self):
return self.__pos
def seek(self, offset, whence=0):
if whence == 0:
newpos = offset
elif whence == 1:
newpos = self.__pos + offset
elif whence == 2:
newpos = self.__eof + offset
assert newpos >= 0 and newpos <= self.__eof
idx = 0
relpos = newpos
while relpos > self.__sizes[idx]:
relpos -= self.__sizes[idx]
idx += 1
self.__files[idx].seek(relpos)
self.__idx = idx
def read(self, n=None):
if n == None:
n = self.__eof - self.__pos
out = []
have_size = 0
while have_size < n:
if self.__idx >= len(self.__files):
break
chunk = self.__files[self.__idx].read(n - have_size)
if len(chunk) == 0:
self.__idx += 1
if self.__idx < len(self.__files):
self.__files[self.__idx].seek(0)
continue
out.append(chunk)
self.__pos += len(chunk)
have_size += len(chunk)
return b''.join(out)
class EncryptedFileIO:
"""
Non-seekable file-like object that reads from a lower-level seekable
file-like object, and transparently decrypts the data stream using a
decryption engine. The decryption engine is assumed to support a
decrypt() method and a blocksize property. The underlying file-like
object is expected to contain a multiple of blocksize bytes, if not,
CorruptedArchiveError is raised.
>>> EncryptedFileIO(io.BytesIO(b'7'*16), AceBlowfish(b'123456789')).read()
b'\\t_\\xd0a}\\x1dh\\xdd>h\\xe7VJ*_\\xea'
>>> EncryptedFileIO(io.BytesIO(b'7'*17), AceBlowfish(b'123456789')).read()
Traceback (most recent call last):
...
CorruptedArchiveError
"""
def __init__(self, f, engine):
self.__file = f
self.__file.seek(0, 2)
self.__eof = self.__file.tell()
self.__file.seek(0)
self.__engine = engine
self.__buffer = b''
def seekable():
return False
def read(self, n=None):
if n == None:
n = self.__eof - (self.__file.tell() - len(self.__buffer))
if n < len(self.__buffer):
rbuf = self.__buffer[:n]
self.__buffer = self.__buffer[n:]
return rbuf
want_bytes = n - len(self.__buffer)
read_bytes = want_bytes
blocksize = self.__engine.blocksize
if want_bytes % blocksize:
read_bytes += blocksize - (want_bytes % blocksize)
buf = self.__file.read(read_bytes)
if len(buf) % blocksize:
raise CorruptedArchiveError("Truncated ciphertext block")
buf = self.__engine.decrypt(buf)
rbuf = self.__buffer + buf[:n]
self.__buffer = buf[n:]
return rbuf
class AceBlowfish:
"""
Decryption engine for ACE Blowfish.
>>> bf = AceBlowfish(b'123456789')
>>> bf.blocksize
8
>>> bf.decrypt(b'\\xFF'*8)
b'\\xb7wF@5.er'
>>> bf.decrypt(b'\\xC7'*8)
b'eE\\x05\\xc4\\xa5\\x85)\\xbc'
>>> bf.decrypt(b'123')
Traceback (most recent call last):
...
AssertionError
"""
SHA1_A = 0x67452301
SHA1_B = 0xefcdab89
SHA1_C = 0x98badcfe
SHA1_D = 0x10325476
SHA1_E = 0xc3d2e1f0
BF_P = (
0x243F6A88, 0x85A308D3, 0x13198A2E, 0x03707344,
0xA4093822, 0x299F31D0, 0x082EFA98, 0xEC4E6C89,
0x452821E6, 0x38D01377, 0xBE5466CF, 0x34E90C6C,
0xC0AC29B7, 0xC97C50DD, 0x3F84D5B5, 0xB5470917,
0x9216D5D9, 0x8979FB1B)
BF_S0 = (
0xD1310BA6, 0x98DFB5AC, 0x2FFD72DB, 0xD01ADFB7,
0xB8E1AFED, 0x6A267E96, 0xBA7C9045, 0xF12C7F99,
0x24A19947, 0xB3916CF7, 0x0801F2E2, 0x858EFC16,
0x636920D8, 0x71574E69, 0xA458FEA3, 0xF4933D7E,
0x0D95748F, 0x728EB658, 0x718BCD58, 0x82154AEE,
0x7B54A41D, 0xC25A59B5, 0x9C30D539, 0x2AF26013,
0xC5D1B023, 0x286085F0, 0xCA417918, 0xB8DB38EF,
0x8E79DCB0, 0x603A180E, 0x6C9E0E8B, 0xB01E8A3E,
0xD71577C1, 0xBD314B27, 0x78AF2FDA, 0x55605C60,
0xE65525F3, 0xAA55AB94, 0x57489862, 0x63E81440,
0x55CA396A, 0x2AAB10B6, 0xB4CC5C34, 0x1141E8CE,
0xA15486AF, 0x7C72E993, 0xB3EE1411, 0x636FBC2A,
0x2DA9C55D, 0x741831F6, 0xCE5C3E16, 0x9B87901E,
0xAFD6BA33, 0x6C24CF5C, 0x7A325381, 0x28958677,
0x3B8F4898, 0x6B4BB9AF, 0xC4BFE81B, 0x66282193,
0x61D809CC, 0xFB21A991, 0x487CAC60, 0x5DEC8032,
0xEF845D5D, 0xE98575B1, 0xDC262302, 0xEB651B88,
0x23893E81, 0xD396ACC5, 0x0F6D6FF3, 0x83F44239,
0x2E0B4482, 0xA4842004, 0x69C8F04A, 0x9E1F9B5E,
0x21C66842, 0xF6E96C9A, 0x670C9C61, 0xABD388F0,
0x6A51A0D2, 0xD8542F68, 0x960FA728, 0xAB5133A3,
0x6EEF0B6C, 0x137A3BE4, 0xBA3BF050, 0x7EFB2A98,
0xA1F1651D, 0x39AF0176, 0x66CA593E, 0x82430E88,
0x8CEE8619, 0x456F9FB4, 0x7D84A5C3, 0x3B8B5EBE,
0xE06F75D8, 0x85C12073, 0x401A449F, 0x56C16AA6,
0x4ED3AA62, 0x363F7706, 0x1BFEDF72, 0x429B023D,
0x37D0D724, 0xD00A1248, 0xDB0FEAD3, 0x49F1C09B,
0x075372C9, 0x80991B7B, 0x25D479D8, 0xF6E8DEF7,
0xE3FE501A, 0xB6794C3B, 0x976CE0BD, 0x04C006BA,
0xC1A94FB6, 0x409F60C4, 0x5E5C9EC2, 0x196A2463,
0x68FB6FAF, 0x3E6C53B5, 0x1339B2EB, 0x3B52EC6F,
0x6DFC511F, 0x9B30952C, 0xCC814544, 0xAF5EBD09,
0xBEE3D004, 0xDE334AFD, 0x660F2807, 0x192E4BB3,
0xC0CBA857, 0x45C8740F, 0xD20B5F39, 0xB9D3FBDB,
0x5579C0BD, 0x1A60320A, 0xD6A100C6, 0x412C7279,
0x679F25FE, 0xFB1FA3CC, 0x8EA5E9F8, 0xDB3222F8,
0x3C7516DF, 0xFD616B15, 0x2F501EC8, 0xAD0552AB,
0x323DB5FA, 0xFD238760, 0x53317B48, 0x3E00DF82,
0x9E5C57BB, 0xCA6F8CA0, 0x1A87562E, 0xDF1769DB,
0xD542A8F6, 0x287EFFC3, 0xAC6732C6, 0x8C4F5573,
0x695B27B0, 0xBBCA58C8, 0xE1FFA35D, 0xB8F011A0,
0x10FA3D98, 0xFD2183B8, 0x4AFCB56C, 0x2DD1D35B,
0x9A53E479, 0xB6F84565, 0xD28E49BC, 0x4BFB9790,
0xE1DDF2DA, 0xA4CB7E33, 0x62FB1341, 0xCEE4C6E8,
0xEF20CADA, 0x36774C01, 0xD07E9EFE, 0x2BF11FB4,
0x95DBDA4D, 0xAE909198, 0xEAAD8E71, 0x6B93D5A0,
0xD08ED1D0, 0xAFC725E0, 0x8E3C5B2F, 0x8E7594B7,
0x8FF6E2FB, 0xF2122B64, 0x8888B812, 0x900DF01C,
0x4FAD5EA0, 0x688FC31C, 0xD1CFF191, 0xB3A8C1AD,
0x2F2F2218, 0xBE0E1777, 0xEA752DFE, 0x8B021FA1,
0xE5A0CC0F, 0xB56F74E8, 0x18ACF3D6, 0xCE89E299,
0xB4A84FE0, 0xFD13E0B7, 0x7CC43B81, 0xD2ADA8D9,
0x165FA266, 0x80957705, 0x93CC7314, 0x211A1477,
0xE6AD2065, 0x77B5FA86, 0xC75442F5, 0xFB9D35CF,
0xEBCDAF0C, 0x7B3E89A0, 0xD6411BD3, 0xAE1E7E49,
0x00250E2D, 0x2071B35E, 0x226800BB, 0x57B8E0AF,
0x2464369B, 0xF009B91E, 0x5563911D, 0x59DFA6AA,
0x78C14389, 0xD95A537F, 0x207D5BA2, 0x02E5B9C5,
0x83260376, 0x6295CFA9, 0x11C81968, 0x4E734A41,
0xB3472DCA, 0x7B14A94A, 0x1B510052, 0x9A532915,
0xD60F573F, 0xBC9BC6E4, 0x2B60A476, 0x81E67400,
0x08BA6FB5, 0x571BE91F, 0xF296EC6B, 0x2A0DD915,
0xB6636521, 0xE7B9F9B6, 0xFF34052E, 0xC5855664,
0x53B02D5D, 0xA99F8FA1, 0x08BA4799, 0x6E85076A)
BF_S1 = (
0x4B7A70E9, 0xB5B32944, 0xDB75092E, 0xC4192623,
0xAD6EA6B0, 0x49A7DF7D, 0x9CEE60B8, 0x8FEDB266,
0xECAA8C71, 0x699A17FF, 0x5664526C, 0xC2B19EE1,
0x193602A5, 0x75094C29, 0xA0591340, 0xE4183A3E,
0x3F54989A, 0x5B429D65, 0x6B8FE4D6, 0x99F73FD6,
0xA1D29C07, 0xEFE830F5, 0x4D2D38E6, 0xF0255DC1,
0x4CDD2086, 0x8470EB26, 0x6382E9C6, 0x021ECC5E,
0x09686B3F, 0x3EBAEFC9, 0x3C971814, 0x6B6A70A1,
0x687F3584, 0x52A0E286, 0xB79C5305, 0xAA500737,
0x3E07841C, 0x7FDEAE5C, 0x8E7D44EC, 0x5716F2B8,
0xB03ADA37, 0xF0500C0D, 0xF01C1F04, 0x0200B3FF,
0xAE0CF51A, 0x3CB574B2, 0x25837A58, 0xDC0921BD,
0xD19113F9, 0x7CA92FF6, 0x94324773, 0x22F54701,
0x3AE5E581, 0x37C2DADC, 0xC8B57634, 0x9AF3DDA7,
0xA9446146, 0x0FD0030E, 0xECC8C73E, 0xA4751E41,
0xE238CD99, 0x3BEA0E2F, 0x3280BBA1, 0x183EB331,
0x4E548B38, 0x4F6DB908, 0x6F420D03, 0xF60A04BF,
0x2CB81290, 0x24977C79, 0x5679B072, 0xBCAF89AF,
0xDE9A771F, 0xD9930810, 0xB38BAE12, 0xDCCF3F2E,
0x5512721F, 0x2E6B7124, 0x501ADDE6, 0x9F84CD87,
0x7A584718, 0x7408DA17, 0xBC9F9ABC, 0xE94B7D8C,
0xEC7AEC3A, 0xDB851DFA, 0x63094366, 0xC464C3D2,
0xEF1C1847, 0x3215D908, 0xDD433B37, 0x24C2BA16,
0x12A14D43, 0x2A65C451, 0x50940002, 0x133AE4DD,
0x71DFF89E, 0x10314E55, 0x81AC77D6, 0x5F11199B,
0x043556F1, 0xD7A3C76B, 0x3C11183B, 0x5924A509,
0xF28FE6ED, 0x97F1FBFA, 0x9EBABF2C, 0x1E153C6E,
0x86E34570, 0xEAE96FB1, 0x860E5E0A, 0x5A3E2AB3,
0x771FE71C, 0x4E3D06FA, 0x2965DCB9, 0x99E71D0F,
0x803E89D6, 0x5266C825, 0x2E4CC978, 0x9C10B36A,
0xC6150EBA, 0x94E2EA78, 0xA5FC3C53, 0x1E0A2DF4,
0xF2F74EA7, 0x361D2B3D, 0x1939260F, 0x19C27960,
0x5223A708, 0xF71312B6, 0xEBADFE6E, 0xEAC31F66,
0xE3BC4595, 0xA67BC883, 0xB17F37D1, 0x018CFF28,
0xC332DDEF, 0xBE6C5AA5, 0x65582185, 0x68AB9802,
0xEECEA50F, 0xDB2F953B, 0x2AEF7DAD, 0x5B6E2F84,
0x1521B628, 0x29076170, 0xECDD4775, 0x619F1510,
0x13CCA830, 0xEB61BD96, 0x0334FE1E, 0xAA0363CF,
0xB5735C90, 0x4C70A239, 0xD59E9E0B, 0xCBAADE14,
0xEECC86BC, 0x60622CA7, 0x9CAB5CAB, 0xB2F3846E,
0x648B1EAF, 0x19BDF0CA, 0xA02369B9, 0x655ABB50,
0x40685A32, 0x3C2AB4B3, 0x319EE9D5, 0xC021B8F7,
0x9B540B19, 0x875FA099, 0x95F7997E, 0x623D7DA8,
0xF837889A, 0x97E32D77, 0x11ED935F, 0x16681281,
0x0E358829, 0xC7E61FD6, 0x96DEDFA1, 0x7858BA99,
0x57F584A5, 0x1B227263, 0x9B83C3FF, 0x1AC24696,
0xCDB30AEB, 0x532E3054, 0x8FD948E4, 0x6DBC3128,
0x58EBF2EF, 0x34C6FFEA, 0xFE28ED61, 0xEE7C3C73,
0x5D4A14D9, 0xE864B7E3, 0x42105D14, 0x203E13E0,
0x45EEE2B6, 0xA3AAABEA, 0xDB6C4F15, 0xFACB4FD0,
0xC742F442, 0xEF6ABBB5, 0x654F3B1D, 0x41CD2105,
0xD81E799E, 0x86854DC7, 0xE44B476A, 0x3D816250,
0xCF62A1F2, 0x5B8D2646, 0xFC8883A0, 0xC1C7B6A3,
0x7F1524C3, 0x69CB7492, 0x47848A0B, 0x5692B285,
0x095BBF00, 0xAD19489D, 0x1462B174, 0x23820E00,
0x58428D2A, 0x0C55F5EA, 0x1DADF43E, 0x233F7061,
0x3372F092, 0x8D937E41, 0xD65FECF1, 0x6C223BDB,
0x7CDE3759, 0xCBEE7460, 0x4085F2A7, 0xCE77326E,
0xA6078084, 0x19F8509E, 0xE8EFD855, 0x61D99735,
0xA969A7AA, 0xC50C06C2, 0x5A04ABFC, 0x800BCADC,
0x9E447A2E, 0xC3453484, 0xFDD56705, 0x0E1E9EC9,
0xDB73DBD3, 0x105588CD, 0x675FDA79, 0xE3674340,
0xC5C43465, 0x713E38D8, 0x3D28F89E, 0xF16DFF20,
0x153E21E7, 0x8FB03D4A, 0xE6E39F2B, 0xDB83ADF7)
BF_S2 = (
0xE93D5A68, 0x948140F7, 0xF64C261C, 0x94692934,
0x411520F7, 0x7602D4F7, 0xBCF46B2E, 0xD4A20068,
0xD4082471, 0x3320F46A, 0x43B7D4B7, 0x500061AF,
0x1E39F62E, 0x97244546, 0x14214F74, 0xBF8B8840,
0x4D95FC1D, 0x96B591AF, 0x70F4DDD3, 0x66A02F45,
0xBFBC09EC, 0x03BD9785, 0x7FAC6DD0, 0x31CB8504,
0x96EB27B3, 0x55FD3941, 0xDA2547E6, 0xABCA0A9A,
0x28507825, 0x530429F4, 0x0A2C86DA, 0xE9B66DFB,
0x68DC1462, 0xD7486900, 0x680EC0A4, 0x27A18DEE,
0x4F3FFEA2, 0xE887AD8C, 0xB58CE006, 0x7AF4D6B6,
0xAACE1E7C, 0xD3375FEC, 0xCE78A399, 0x406B2A42,
0x20FE9E35, 0xD9F385B9, 0xEE39D7AB, 0x3B124E8B,
0x1DC9FAF7, 0x4B6D1856, 0x26A36631, 0xEAE397B2,
0x3A6EFA74, 0xDD5B4332, 0x6841E7F7, 0xCA7820FB,
0xFB0AF54E, 0xD8FEB397, 0x454056AC, 0xBA489527,
0x55533A3A, 0x20838D87, 0xFE6BA9B7, 0xD096954B,
0x55A867BC, 0xA1159A58, 0xCCA92963, 0x99E1DB33,
0xA62A4A56, 0x3F3125F9, 0x5EF47E1C, 0x9029317C,
0xFDF8E802, 0x04272F70, 0x80BB155C, 0x05282CE3,
0x95C11548, 0xE4C66D22, 0x48C1133F, 0xC70F86DC,
0x07F9C9EE, 0x41041F0F, 0x404779A4, 0x5D886E17,
0x325F51EB, 0xD59BC0D1, 0xF2BCC18F, 0x41113564,
0x257B7834, 0x602A9C60, 0xDFF8E8A3, 0x1F636C1B,
0x0E12B4C2, 0x02E1329E, 0xAF664FD1, 0xCAD18115,
0x6B2395E0, 0x333E92E1, 0x3B240B62, 0xEEBEB922,
0x85B2A20E, 0xE6BA0D99, 0xDE720C8C, 0x2DA2F728,
0xD0127845, 0x95B794FD, 0x647D0862, 0xE7CCF5F0,
0x5449A36F, 0x877D48FA, 0xC39DFD27, 0xF33E8D1E,
0x0A476341, 0x992EFF74, 0x3A6F6EAB, 0xF4F8FD37,
0xA812DC60, 0xA1EBDDF8, 0x991BE14C, 0xDB6E6B0D,
0xC67B5510, 0x6D672C37, 0x2765D43B, 0xDCD0E804,
0xF1290DC7, 0xCC00FFA3, 0xB5390F92, 0x690FED0B,
0x667B9FFB, 0xCEDB7D9C, 0xA091CF0B, 0xD9155EA3,
0xBB132F88, 0x515BAD24, 0x7B9479BF, 0x763BD6EB,
0x37392EB3, 0xCC115979, 0x8026E297, 0xF42E312D,
0x6842ADA7, 0xC66A2B3B, 0x12754CCC, 0x782EF11C,
0x6A124237, 0xB79251E7, 0x06A1BBE6, 0x4BFB6350,
0x1A6B1018, 0x11CAEDFA, 0x3D25BDD8, 0xE2E1C3C9,
0x44421659, 0x0A121386, 0xD90CEC6E, 0xD5ABEA2A,
0x64AF674E, 0xDA86A85F, 0xBEBFE988, 0x64E4C3FE,
0x9DBC8057, 0xF0F7C086, 0x60787BF8, 0x6003604D,
0xD1FD8346, 0xF6381FB0, 0x7745AE04, 0xD736FCCC,
0x83426B33, 0xF01EAB71, 0xB0804187, 0x3C005E5F,
0x77A057BE, 0xBDE8AE24, 0x55464299, 0xBF582E61,
0x4E58F48F, 0xF2DDFDA2, 0xF474EF38, 0x8789BDC2,
0x5366F9C3, 0xC8B38E74, 0xB475F255, 0x46FCD9B9,
0x7AEB2661, 0x8B1DDF84, 0x846A0E79, 0x915F95E2,
0x466E598E, 0x20B45770, 0x8CD55591, 0xC902DE4C,
0xB90BACE1, 0xBB8205D0, 0x11A86248, 0x7574A99E,
0xB77F19B6, 0xE0A9DC09, 0x662D09A1, 0xC4324633,
0xE85A1F02, 0x09F0BE8C, 0x4A99A025, 0x1D6EFE10,
0x1AB93D1D, 0x0BA5A4DF, 0xA186F20F, 0x2868F169,
0xDCB7DA83, 0x573906FE, 0xA1E2CE9B, 0x4FCD7F52,
0x50115E01, 0xA70683FA, 0xA002B5C4, 0x0DE6D027,
0x9AF88C27, 0x773F8641, 0xC3604C06, 0x61A806B5,
0xF0177A28, 0xC0F586E0, 0x006058AA, 0x30DC7D62,
0x11E69ED7, 0x2338EA63, 0x53C2DD94, 0xC2C21634,
0xBBCBEE56, 0x90BCB6DE, 0xEBFC7DA1, 0xCE591D76,
0x6F05E409, 0x4B7C0188, 0x39720A3D, 0x7C927C24,
0x86E3725F, 0x724D9DB9, 0x1AC15BB4, 0xD39EB8FC,
0xED545578, 0x08FCA5B5, 0xD83D7CD3, 0x4DAD0FC4,
0x1E50EF5E, 0xB161E6F8, 0xA28514D9, 0x6C51133C,
0x6FD5C7E7, 0x56E14EC4, 0x362ABFCE, 0xDDC6C837,
0xD79A3234, 0x92638212, 0x670EFA8E, 0x406000E0)
BF_S3 = (
0x3A39CE37, 0xD3FAF5CF, 0xABC27737, 0x5AC52D1B,
0x5CB0679E, 0x4FA33742, 0xD3822740, 0x99BC9BBE,
0xD5118E9D, 0xBF0F7315, 0xD62D1C7E, 0xC700C47B,
0xB78C1B6B, 0x21A19045, 0xB26EB1BE, 0x6A366EB4,
0x5748AB2F, 0xBC946E79, 0xC6A376D2, 0x6549C2C8,
0x530FF8EE, 0x468DDE7D, 0xD5730A1D, 0x4CD04DC6,
0x2939BBDB, 0xA9BA4650, 0xAC9526E8, 0xBE5EE304,
0xA1FAD5F0, 0x6A2D519A, 0x63EF8CE2, 0x9A86EE22,
0xC089C2B8, 0x43242EF6, 0xA51E03AA, 0x9CF2D0A4,
0x83C061BA, 0x9BE96A4D, 0x8FE51550, 0xBA645BD6,
0x2826A2F9, 0xA73A3AE1, 0x4BA99586, 0xEF5562E9,
0xC72FEFD3, 0xF752F7DA, 0x3F046F69, 0x77FA0A59,
0x80E4A915, 0x87B08601, 0x9B09E6AD, 0x3B3EE593,
0xE990FD5A, 0x9E34D797, 0x2CF0B7D9, 0x022B8B51,
0x96D5AC3A, 0x017DA67D, 0xD1CF3ED6, 0x7C7D2D28,
0x1F9F25CF, 0xADF2B89B, 0x5AD6B472, 0x5A88F54C,
0xE029AC71, 0xE019A5E6, 0x47B0ACFD, 0xED93FA9B,
0xE8D3C48D, 0x283B57CC, 0xF8D56629, 0x79132E28,
0x785F0191, 0xED756055, 0xF7960E44, 0xE3D35E8C,
0x15056DD4, 0x88F46DBA, 0x03A16125, 0x0564F0BD,
0xC3EB9E15, 0x3C9057A2, 0x97271AEC, 0xA93A072A,
0x1B3F6D9B, 0x1E6321F5, 0xF59C66FB, 0x26DCF319,
0x7533D928, 0xB155FDF5, 0x03563482, 0x8ABA3CBB,
0x28517711, 0xC20AD9F8, 0xABCC5167, 0xCCAD925F,
0x4DE81751, 0x3830DC8E, 0x379D5862, 0x9320F991,
0xEA7A90C2, 0xFB3E7BCE, 0x5121CE64, 0x774FBE32,
0xA8B6E37E, 0xC3293D46, 0x48DE5369, 0x6413E680,
0xA2AE0810, 0xDD6DB224, 0x69852DFD, 0x09072166,
0xB39A460A, 0x6445C0DD, 0x586CDECF, 0x1C20C8AE,
0x5BBEF7DD, 0x1B588D40, 0xCCD2017F, 0x6BB4E3BB,
0xDDA26A7E, 0x3A59FF45, 0x3E350A44, 0xBCB4CDD5,
0x72EACEA8, 0xFA6484BB, 0x8D6612AE, 0xBF3C6F47,
0xD29BE463, 0x542F5D9E, 0xAEC2771B, 0xF64E6370,
0x740E0D8D, 0xE75B1357, 0xF8721671, 0xAF537D5D,
0x4040CB08, 0x4EB4E2CC, 0x34D2466A, 0x0115AF84,
0xE1B00428, 0x95983A1D, 0x06B89FB4, 0xCE6EA048,
0x6F3F3B82, 0x3520AB82, 0x011A1D4B, 0x277227F8,
0x611560B1, 0xE7933FDC, 0xBB3A792B, 0x344525BD,
0xA08839E1, 0x51CE794B, 0x2F32C9B7, 0xA01FBAC9,
0xE01CC87E, 0xBCC7D1F6, 0xCF0111C3, 0xA1E8AAC7,
0x1A908749, 0xD44FBD9A, 0xD0DADECB, 0xD50ADA38,
0x0339C32A, 0xC6913667, 0x8DF9317C, 0xE0B12B4F,
0xF79E59B7, 0x43F5BB3A, 0xF2D519FF, 0x27D9459C,
0xBF97222C, 0x15E6FC2A, 0x0F91FC71, 0x9B941525,
0xFAE59361, 0xCEB69CEB, 0xC2A86459, 0x12BAA8D1,
0xB6C1075E, 0xE3056A0C, 0x10D25065, 0xCB03A442,
0xE0EC6E0E, 0x1698DB3B, 0x4C98A0BE, 0x3278E964,
0x9F1F9532, 0xE0D392DF, 0xD3A0342B, 0x8971F21E,
0x1B0A7441, 0x4BA3348C, 0xC5BE7120, 0xC37632D8,
0xDF359F8D, 0x9B992F2E, 0xE60B6F47, 0x0FE3F11D,
0xE54CDA54, 0x1EDAD891, 0xCE6279CF, 0xCD3E7E6F,
0x1618B166, 0xFD2C1D05, 0x848FD2C5, 0xF6FB2299,
0xF523F357, 0xA6327623, 0x93A83531, 0x56CCCD02,
0xACF08162, 0x5A75EBB5, 0x6E163697, 0x88D273CC,
0xDE966292, 0x81B949D0, 0x4C50901B, 0x71C65614,
0xE6C6C7BD, 0x327A140A, 0x45E1D006, 0xC3F27B9A,
0xC9AA53FD, 0x62A80F00, 0xBB25BFE2, 0x35BDD2F6,
0x71126905, 0xB2040222, 0xB6CBCF7C, 0xCD769C2B,
0x53113EC0, 0x1640E3D3, 0x38ABBD60, 0x2547ADF0,
0xBA38209C, 0xF746CE76, 0x77AFA1C5, 0x20756060,
0x85CBFE4E, 0x8AE88DD8, 0x7AAAF9B0, 0x4CF9AA7E,
0x1948C25C, 0x02FB8A8C, 0x01C36AE4, 0xD6EBE1F9,
0x90D4F869, 0xA65CDEA0, 0x3F09252D, 0xC208E69F,
0xB74E6132, 0xCE77E25B, 0x578FDFE3, 0x3AC372E6)
def __init__(self, pwd):
"""
Initialize decryption engine with a key derived from password *pwd*,
which can be str or bytes.
"""
if isinstance(pwd, str):
pwd = pwd.encode('utf-8')
self._bf_init(self._derive_key(pwd))
def _derive_key(self, pwd):
"""
Derive the decryption key from password bytes *pwd* using a single
application of SHA-1 using non-standard padding. The password is
truncated to a maximum of 50 bytes before key derivation.
>>> AceBlowfish._derive_key(None, b'123456789')
(3071200156, 3325860325, 4058316933, 1308772094, 896611998)
"""
if len(pwd) > 50:
pwd = pwd[:50]
buf = pwd + bytes([0x80] + [0] * (64 - len(pwd) - 5))
state = []
state.extend(struct.unpack('<15L', buf))
state.append(len(pwd) << 3)
for i in range(len(state), 80):
state.append(state[i-16] ^ state[i-14] ^ state[i-8] ^ state[i-3])
a = AceBlowfish.SHA1_A
b = AceBlowfish.SHA1_B
c = AceBlowfish.SHA1_C
d = AceBlowfish.SHA1_D
e = AceBlowfish.SHA1_E
for i in range(20):
a, b, c, d, e = \
c_sum32(c_rot32(a, 5), ((b&c)|(~b&d)), e, state[i],
0x5a827999), a, c_rot32(b, 30), c, d
for i in range(20, 40):
a, b, c, d, e = \
c_sum32(c_rot32(a, 5), (b^c^d), e, state[i],
0x6ed9eba1), a, c_rot32(b, 30), c, d
for i in range(40, 60):
a, b, c, d, e = \
c_sum32(c_rot32(a, 5), ((b&c)|(b&d)|(c&d)), e, state[i],
0x8f1bbcdc), a, c_rot32(b, 30), c, d
for i in range(60, 80):
a, b, c, d, e = \
c_sum32(c_rot32(a, 5), (b^c^d), e, state[i],
0xca62c1d6), a, c_rot32(b, 30), c, d
a = c_add32(a, AceBlowfish.SHA1_A)
b = c_add32(b, AceBlowfish.SHA1_B)
c = c_add32(c, AceBlowfish.SHA1_C)
d = c_add32(d, AceBlowfish.SHA1_D)
e = c_add32(e, AceBlowfish.SHA1_E)
return (a, b, c, d, e)
def _bf_init(self, key):
"""
Initialize blowfish state using 160-bit key *key* as list or tuple of
integers.
"""
self.__p = [self.BF_P[i] ^ key[i % len(key)] \
for i in list(range(len(self.BF_P)))]
self.__s = (list(self.BF_S0), list(self.BF_S1),
list(self.BF_S2), list(self.BF_S3))
self.__lastcl = 0
self.__lastcr = 0
l = r = 0
for i in range(0, 18, 2):
l, r = self._bf_encrypt_block(l, r)
self.__p[i] = l
self.__p[i + 1] = r
for i in range(0, 4):
for j in range(0, 256, 2):
l, r = self._bf_encrypt_block(l, r)
self.__s[i][j] = l
self.__s[i][j + 1] = r
def _bf_func(self, x):
"""
The blowfish round function operating on an integer.
"""
h = c_add32(self.__s[0][x >> 24], self.__s[1][x >> 16 & 0xff])
return c_add32((h ^ self.__s[2][x >> 8 & 0xff]), self.__s[3][x & 0xff])
def _bf_encrypt_block(self, l, r):
"""
Encrypt a single block consisting of integers *l* and *r*.
"""
for i in range(0, 16, 2):
l ^= self.__p[i]
r ^= self._bf_func(l)
r ^= self.__p[i+1]
l ^= self._bf_func(r)
l ^= self.__p[16]
r ^= self.__p[17]
return (r, l)
def _bf_decrypt_block(self, l, r):
"""
Decrypt a single block consisting of integers *l* and *r*.
"""
for i in range(16, 0, -2):
l ^= self.__p[i+1]
r ^= self._bf_func(l)
r ^= self.__p[i]
l ^= self._bf_func(r)
l ^= self.__p[1]
r ^= self.__p[0]
return (r, l)
def decrypt(self, buf):
"""
Decrypt a buffer of complete blocks, i.e. of length that is a multiple
of the block size returned by the blocksize property.
AceBlowfish uses Blowfish in CBC mode with an IV of all zeroes on the
first call, and an IV of the last ciphertext block on subsequent calls.
Does not remove any padding.
"""
assert len(buf) % self.blocksize == 0
out = []
for i in range(0, len(buf), 8):
cl, cr = struct.unpack('<LL', buf[i:i+8])
pl, pr = self._bf_decrypt_block(cl, cr)
pl ^= self.__lastcl
pr ^= self.__lastcr
self.__lastcl = cl
self.__lastcr = cr
out.append(struct.pack('<LL', pl, pr))
return b''.join(out)
@property
def blocksize(self):
"""
Return the block size of the decryption engine in bytes.
The decrypt() method will only accept buffers containing a multiple of
the block size of bytes.
"""
return 8
class AceCRC32:
"""
Calculate an ACE CRC-32 checksum.
ACE CRC-32 uses the standard CRC-32 polynomial, bit ordering and
initialization vector, but does not invert the resulting checksum.
This implementation uses :meth:`zlib.crc32` with inverted state,
inverted initialization vector and inverted output in order to
construct ACE CRC-32 from standard CRC-32.
>>> crc = AceCRC32()
>>> crc += b"12345"
>>> crc += b"6789"
>>> crc.sum
873187033
>>> crc == 873187033
True
"""
def __init__(self, buf=b''):
"""
Initialize and add bytes in *buf* into checksum.
"""
self.__state = 0
if len(buf) > 0:
self += buf
def __iadd__(self, buf):
"""
Adding a buffer of bytes into the checksum, updating the rolling
checksum from all previously added buffers.
"""
self.__state = zlib.crc32(buf, self.__state)
return self
def __eq__(self, other):
"""
Compare the checksum to a fixed value or another ACE CRC32 object.
"""
return self.sum == other
def __format__(self, format_spec):
"""
Format the checksum for printing.
"""
return self.sum.__format__(format_spec)
def __str__(self):
"""
String representation of object is hex value of checksum.
"""
return "0x%08x" % self.sum
@property
def sum(self):
"""
The final checksum.
"""
return self.__state ^ 0xFFFFFFFF
class AceCRC16(AceCRC32):
"""
Calculate an ACE CRC-16 checksum, which is actually just the lower 16 bits
of an ACE CRC-32.
>>> crc = AceCRC16()
>>> crc += b"12345"
>>> crc += b"6789"
>>> crc.sum
50905
>>> crc == 50905
True
"""
def __str__(self):
"""
String representation of object is hex value of checksum.
"""
return "0x%04x" % self.sum
@property
def sum(self):
"""
The checksum.
"""
return super().sum & 0xFFFF
def ace_crc32(buf):
"""
Return the ACE CRC-32 checksum of the bytes in *buf*.
>>> ace_crc32(b"123456789")
873187033
"""
return AceCRC32(buf).sum
def ace_crc16(buf):
"""
Return the ACE CRC-16 checksum of the bytes in *buf*.
>>> ace_crc16(b"123456789")
50905
"""
return AceCRC16(buf).sum
class BitStream:
"""
Intel-endian 32bit-byte-swapped, MSB first bitstream, reading from an
underlying file-like object that does not need to be seekable, but is
expected to be a multiple of 4 in length.
>>> bs = BitStream(io.BytesIO(b'01234567'))
>>> bs.peek_bits(31)
429463704
>>> bs.read_bits(31)
429463704
>>> bs.skip_bits(3)
>>> bs.read_bits(5)
27
>>> bs.read_golomb_rice(3)
20
>>> bs.read_golomb_rice(2, True)
-2
>>> bs.read_knownwidth_uint(10)
618
>>> bs.read_bits(7)
52
>>> bs.peek_bits(31)
0
>>> bs.read_bits(1)
Traceback (most recent call last):
...
EOFError
>>> BitStream(io.BytesIO(b'012')).read_bits(31)
Traceback (most recent call last):
...
ValueError
"""
@staticmethod
def _getbits(value, start, length):
"""
Return *length* bits from byte *value*, starting at position *start*.
Behaviour is undefined for start < 0, length < 0 or start + length > 32.
"""
#assert start >= 0 and length >= 0 and start + length <= 32
mask = ((0xFFFFFFFF << (32 - length)) & 0xFFFFFFFF) >> start
return (value & mask) >> (32 - length - start)
def __init__(self, f):
"""
Initialize BitStream reading from file-like object *f* until EOF.
"""
self.__file = f
self.__buf = array.array('I')
self.__len = 0 # in bits
self.__pos = 0 # in bits
self._refill()
def _refill(self):
"""
Refill the internal buffer with data read from file.
"""
tmpbuf = self.__file.read(FILE_BLOCKSIZE)
if len(tmpbuf) == 0:
raise EOFError("Cannot refill beyond EOF")
if len(tmpbuf) % 4 != 0:
raise ValueError("Truncated 32-bit word from file-like object")
newbuf = self.__buf[-1:]
for i in range(0, len(tmpbuf), 4):
newbuf.append(struct.unpack('<L', tmpbuf[i:i+4])[0])
if self.__pos > 0:
self.__pos -= (self.__len - 32)
self.__buf = newbuf
self.__len = 32 * len(newbuf)
def skip_bits(self, bits):
"""
Skip *bits* bits in the stream.
Raise EOFError when skipping beyond the end of the input file data.
The pure-python implementation supports skipping arbitrarily many
*bits* while the c implementation is limited to a maximum of 31.
"""
if self.__pos + bits > self.__len:
self._refill()
self.__pos += bits
def peek_bits(self, bits):
"""
Peek at next *bits* bits in the stream without incrementing position.
A maximum of 31 bits beyond the end of the input file data are
guaranteed to be peekable; these bits are always unset.
The pure-python implementation supports peeking arbitrarily many
*bits* while the c implementation is limited to a maximum of 31.
"""
if self.__pos + bits > self.__len:
try:
self._refill()
except EOFError:
if len(self.__buf) * 32 == self.__len:
self.__buf.append(0)
if self.__pos + bits > self.__len + 31:
raise
peeked = min(bits, 32 - (self.__pos % 32))
res = self._getbits(self.__buf[self.__pos // 32],
self.__pos % 32, peeked)
while bits - peeked >= 32:
res <<= 32
res += self.__buf[(self.__pos + peeked) // 32]
peeked += 32
if bits - peeked > 0:
res <<= bits - peeked
res += self._getbits(self.__buf[(self.__pos + peeked) // 32],
0, bits - peeked)
return res
def read_bits(self, bits):
"""
Read *bits* bits from bitstream and increment position accordingly.
The pure-python implementation supports reading arbitrarily many
*bits* while the c implementation is limited to a maximum of 31.
"""
value = self.peek_bits(bits)
self.skip_bits(bits)
return value
def read_golomb_rice(self, r_bits, signed=False):
"""
Read a Golomb-Rice code with *r_bits* remainder bits and an arbitrary
number of quotient bits from bitstream and return the represented
value. Iff *signed* is True, interpret the lowest order bit as sign
bit and return a signed integer.
"""
if r_bits == 0:
value = 0
else:
assert r_bits > 0
value = self.read_bits(r_bits)
while self.read_bits(1) == 1:
value += 1 << r_bits
if signed == False:
return value
if value & 1:
return - (value >> 1) - 1
else:
return value >> 1
def read_knownwidth_uint(self, bits):
"""
Read an unsigned integer with previously known bit width *bits* from
stream. The most significant bit is not encoded in the bit stream,
because it is always 1.
"""
if bits < 2:
return bits
bits -= 1
return self.read_bits(bits) + (1 << bits)
if acebitstream != None:
class BitStream_c(acebitstream.BitStream):
read_golomb_rice = BitStream.read_golomb_rice
read_knownwidth_uint = BitStream.read_knownwidth_uint
BitStream_c.__doc__ = BitStream.__doc__
BitStream = BitStream_c
class AceMode:
"""
Represent and parse compression submode information from a bitstream.
"""
@classmethod
def read_from(cls, bs):
mode = cls(bs.read_bits(8))
if mode.mode == ACE.MODE_LZ77_DELTA:
mode.delta_dist = bs.read_bits(8)
mode.delta_len = bs.read_bits(17)
elif mode.mode == ACE.MODE_LZ77_EXE:
mode.exe_mode = bs.read_bits(8)
if DEBUG:
eprint(mode)
return mode
def __init__(self, mode):
self.mode = mode
def __str__(self):
args = ''
if self.mode == ACE.MODE_LZ77_DELTA:
args = " delta_dist=%i delta_len=%i" % (self.delta_dist,
self.delta_len)
elif self.mode == ACE.MODE_LZ77_EXE:
args = " exe_mode=%i" % self.exe_mode
return "mode %s(%i)%s" % (ACE.mode_str(self.mode), self.mode, args)
class Huffman:
"""
Huffman decoder engine.
"""
class Tree:
"""
Huffman tree reconstructed from bitstream, internally represented by
a table mapping (length-extended) codes to symbols and a table mapping
symbols to bit widths.
"""
def __init__(self, codes, widths, max_width):
self.codes = codes
self.widths = widths
self.max_width = max_width
def read_symbol(self, bs):
"""
Read a single Huffman symbol from BitStream *bs* by peeking the
maximum code length in bits from the bit stream, looking up the
symbol and its width, and finally skipping the actual width of
the code for the symbol in the bit stream.
"""
maxwidth_code = bs.peek_bits(self.max_width)
if maxwidth_code >= len(self.codes):
# Not sure if we could prevent this from happening on malformed
# input by improving how we choose max_width and codes; so far
# only happens on malformed input.
raise CorruptedArchiveError("maxwidth_code >= len(codes)")
symbol = self.codes[maxwidth_code]
bs.skip_bits(self.widths[symbol])
return symbol
WIDTHWIDTHBITS = 3
MAXWIDTHWIDTH = (1 << WIDTHWIDTHBITS) - 1
@staticmethod
def _quicksort(keys, values):
"""
In-place quicksort of lists *keys* and *values* in descending order of
*keys*. Python uses a stable sorting algorithm, while the
reconstruction of the correct Huffman trees depends on the sorting
being unstable in exactly the way of this quicksort implementation.
>>> k, v = [1, 0, 0, 1, 2, 0, 0], list(range(7))
>>> Huffman._quicksort(k, v)
>>> (k, v)
([2, 1, 1, 0, 0, 0, 0], [4, 0, 3, 5, 6, 2, 1])
"""
def _quicksort_subrange(left, right):
def _list_swap(_list, a, b):
"""
>>> a = list(range(9))
>>> _list_swap(a, 3, 6)
[0, 1, 2, 6, 4, 5, 3, 7, 8, 9]
"""
_list[a], _list[b] = _list[b], _list[a]
new_left = left
new_right = right
m = keys[right]
while True:
while keys[new_left] > m:
new_left += 1
while keys[new_right] < m:
new_right -= 1
if new_left <= new_right:
_list_swap(keys, new_left, new_right)
_list_swap(values, new_left, new_right)
new_left += 1
new_right -= 1
if new_left >= new_right:
break
if left < new_right:
if left < new_right - 1:
_quicksort_subrange(left, new_right)
else:
if keys[left] < keys[new_right]:
_list_swap(keys, left, new_right)
_list_swap(values, left, new_right)
if right > new_left:
if new_left < right - 1:
_quicksort_subrange(new_left, right)
else:
if keys[new_left] < keys[right]:
_list_swap(keys, new_left, right)
_list_swap(values, new_left, right)
assert len(keys) == len(values)
_quicksort_subrange(0, len(keys) - 1)
@staticmethod
def _make_tree(widths, max_width):
"""
Calculate the list of Huffman codes corresponding to the symbols
implicitly described by the list of *widths* and maximal width
*max_width*, and return a Huffman.Tree object representing the
resulting Huffman tree.
"""
sorted_symbols = list(range(len(widths)))
sorted_widths = list(widths)
Huffman._quicksort(sorted_widths, sorted_symbols)
used = 0
while used < len(sorted_widths) and sorted_widths[used] != 0:
used += 1
if used < 2:
widths[sorted_symbols[0]] = 1
if used == 0:
used += 1
del sorted_symbols[used:]
del sorted_widths[used:]
codes = []
max_codes = 1 << max_width
for sym, wdt in zip(reversed(sorted_symbols), reversed(sorted_widths)):
if wdt > max_width:
raise CorruptedArchiveError("wdt > max_width")
repeat = 1 << (max_width - wdt)
codes.extend([sym] * repeat)
if len(codes) > max_codes:
raise CorruptedArchiveError("len(codes) > max_codes")
return Huffman.Tree(codes, widths, max_width)
@staticmethod
def read_tree(bs, max_width, num_codes):
"""
Read a Huffman tree consisting of codes and their widths from
BitStream *bs*. The caller specifies the maximum width of a single
code *max_width* and the number of codes *num_codes*; these are
required to reconstruct the Huffman tree from the widths stored in
the bit stream.
"""
num_widths = bs.read_bits(9) + 1
if num_widths > num_codes + 1:
num_widths = num_codes + 1
lower_width = bs.read_bits(4)
upper_width = bs.read_bits(4)
width_widths = []
width_num_widths = upper_width + 1
for i in range(width_num_widths):
width_widths.append(bs.read_bits(Huffman.WIDTHWIDTHBITS))
width_tree = Huffman._make_tree(width_widths, Huffman.MAXWIDTHWIDTH)
widths = []
while len(widths) < num_widths:
symbol = width_tree.read_symbol(bs)
if symbol < upper_width:
widths.append(symbol)
else:
length = bs.read_bits(4) + 4
length = min(length, num_widths - len(widths))
widths.extend([0] * length)
if upper_width > 0:
for i in range(1, len(widths)):
widths[i] = (widths[i] + widths[i - 1]) % upper_width
for i in range(len(widths)):
if widths[i] > 0:
widths[i] += lower_width
return Huffman._make_tree(widths, max_width)
class LZ77:
"""
ACE 1.0 and ACE 2.0 LZ77 mode decompression engine.
Plain LZ77 compression over a Huffman-encoded symbol stream.
"""
class SymbolReader:
"""
Read blocks of Huffman-encoded LZ77 symbols.
Two Huffman trees are used, one for the LZ77 symbols (main codes) and
one for the length parameters (len codes).
"""
def __init__(self):
self.__syms_to_read = 0
def _read_trees(self, bs):
"""
Read the Huffman trees as well as the blocksize from BitStream
*bs*; essentially this starts reading into a next block of symbols.
"""
self.__main_tree = Huffman.read_tree(bs, LZ77.MAXCODEWIDTH,
LZ77.NUMMAINCODES)
self.__len_tree = Huffman.read_tree(bs, LZ77.MAXCODEWIDTH,
LZ77.NUMLENCODES)
self.__syms_to_read = bs.read_bits(15)
def read_main_symbol(self, bs):
"""
Read a main symbol from BitStream *bs*.
"""
if self.__syms_to_read == 0:
self._read_trees(bs)
self.__syms_to_read -= 1
return self.__main_tree.read_symbol(bs)
def read_len_symbol(self, bs):
"""
Read a length symbol from BitStream *bs*.
"""
return self.__len_tree.read_symbol(bs)
class DistHist:
"""
Distance value cache for storing the last SIZE used LZ77 distances.
>>> dh = LZ77.DistHist()
>>> dh.append(1);dh.append(2);dh.append(3);dh.append(4);dh.append(5)
>>> dh.retrieve(2)
3
>>> dh.retrieve(0)
3
>>> dh.retrieve(1)
5
>>> dh.retrieve(1)
3
"""
SIZE = 4
def __init__(self):
self.__hist = [0] * self.SIZE
def append(self, dist):
self.__hist.pop(0)
self.__hist.append(dist)
def retrieve(self, offset):
assert offset >= 0 and offset < self.SIZE
dist = self.__hist.pop(self.SIZE - offset - 1)
self.__hist.append(dist)
return dist
class Dictionary:
"""
LZ77 dictionary. Stores at least the last dictionary-size number of
decompressed bytes and supports the LZ77 copy operation. Also doubles
as decompressed bytes buffer. Consequently, the dictionary will grow
as bytes are appended to it until copyout or copyin are called.
>>> dic = LZ77.Dictionary(4, 8)
>>> dic.append(1); dic.append(2); dic.extend((3,4))
>>> dic.copy(4, 4)
>>> dic.copyout(8)
[1, 2, 3, 4, 1, 2, 3, 4]
>>> dic.copy(9, 1)
Traceback (most recent call last):
...
CorruptedArchiveError
"""
def __init__(self, minsize, maxsize):
self.__dicdata = []
self.__dicsize = minsize
self.__maxsize = maxsize
def set_size(self, dicsize):
"""
Set expected dictionary size for next decompression run.
"""
self.__dicsize = min(max(dicsize, self.__dicsize), self.__maxsize)
def append(self, char):
"""
Append output byte *char* to dictionary.
"""
self.__dicdata.append(char)
def extend(self, buf):
"""
Append output bytes *buf* to dictionary.
"""
self.__dicdata.extend(buf)
def copy(self, dist, n):
"""
Copy *n* previously produced output bytes to end of dictionary,
starting from position *dist* away from the end.
"""
source_pos = len(self.__dicdata) - dist
if source_pos < 0:
raise CorruptedArchiveError("LZ77 copy src out of bounds")
# copy needs to be byte-wise for overlapping src and dst
for i in range(source_pos, source_pos + n):
self.__dicdata.append(self.__dicdata[i])
def copyin(self, buf):
"""
Copy output bytes produced by other decompression methods
from *buf* into dictionary. This operation may cause the
dictionary to shrink to the indended dictionary size; make sure
to copyout all needed output bytes before calling copyin.
"""
self.extend(buf)
self._truncate()
def copyout(self, n):
"""
Return copy of last *n* appended output bytes for handing them
to the caller. This operation may cause the dictionary to shrink
to the intended dictionary size.
"""
if n > 0:
assert n <= len(self.__dicdata)
chunk = self.__dicdata[-n:]
else:
chunk = []
self._truncate()
return chunk
def _truncate(self):
# only perform actual truncation when dictionary exceeds 4 times
# it's supposed size in order to prevent excessive data copying
if len(self.__dicdata) > 4 * self.__dicsize:
self.__dicdata = self.__dicdata[-self.__dicsize:]
# 0..255 character literals
# 256..259 copy from dictionary, dist from dist history -1..-4
# 260..282 copy from dictionary, dist 0..22 bits from bitstream
# 283 type code
MAXCODEWIDTH = 11
MAXLEN = 259
MAXDISTATLEN2 = 255
MAXDISTATLEN3 = 8191
MINDICBITS = 10
MAXDICBITS = 22
MINDICSIZE = 1 << MINDICBITS
MAXDICSIZE = 1 << MAXDICBITS
TYPECODE = 260 + MAXDICBITS + 1
NUMMAINCODES = 260 + MAXDICBITS + 2
NUMLENCODES = 256 - 1
def __init__(self):
self.__dictionary = LZ77.Dictionary(LZ77.MINDICSIZE, LZ77.MAXDICSIZE)
def reinit(self):
"""
Reinitialize the LZ77 decompression engine.
Reset all data dependent state to initial values.
"""
self.__symreader = LZ77.SymbolReader()
self.__disthist = LZ77.DistHist()
self.__leftover = []
def dic_setsize(self, dicsize):
"""
Set the required dictionary size for the next LZ77 decompression run.
"""
self.__dictionary.set_size(dicsize)
def dic_register(self, buf):
"""
Register bytes in *buf* produced by other decompression modes into
the LZ77 dictionary.
"""
self.__dictionary.copyin(buf)
def read(self, bs, want_size):
"""
Read a block of LZ77 compressed data from BitStream *bs*.
Reading will stop when *want_size* output bytes can be provided,
or when a block ends, i.e. when a mode instruction is found.
Returns a tuple of the output byte-like and the mode instruction.
"""
assert want_size > 0
have_size = 0
if len(self.__leftover) > 0:
self.__dictionary.extend(self.__leftover)
have_size += len(self.__leftover)
self.__leftover = []
next_mode = None
while have_size < want_size:
symbol = self.__symreader.read_main_symbol(bs)
if symbol <= 255:
self.__dictionary.append(symbol)
have_size += 1
elif symbol < LZ77.TYPECODE:
if symbol <= 259:
copy_len = self.__symreader.read_len_symbol(bs)
offset = symbol & 0x03
copy_dist = self.__disthist.retrieve(offset)
if offset > 1:
copy_len += 3
else:
copy_len += 2
else:
copy_dist = bs.read_knownwidth_uint(symbol - 260)
copy_len = self.__symreader.read_len_symbol(bs)
self.__disthist.append(copy_dist)
if copy_dist <= LZ77.MAXDISTATLEN2:
copy_len += 2
elif copy_dist <= LZ77.MAXDISTATLEN3:
copy_len += 3
else:
copy_len += 4
copy_dist += 1
if have_size + copy_len > want_size:
raise CorruptedArchiveError("LZ77 copy exceeds want_size")
self.__dictionary.copy(copy_dist, copy_len)
have_size += copy_len
elif symbol == LZ77.TYPECODE:
next_mode = AceMode.read_from(bs)
break
else:
raise CorruptedArchiveError("LZ77 symbol > LZ77.TYPECODE")
chunk = self.__dictionary.copyout(have_size)
return (chunk, next_mode)
class Sound:
"""
ACE 2.0 SOUND mode decompression engine.
Multi-channel audio predictor over Huffman-encoding, resulting in a higher
compression ratio for uncompressed mono/stereo 8/16 bit sound data.
"""
class SymbolReader:
"""
Read blocks of Huffman-encoded SOUND symbols.
For each channel, three Huffman trees are used.
"""
def __init__(self, num_models):
self.__trees = [None] * num_models
self.__syms_to_read = 0
def _read_trees(self, bs):
"""
Read the Huffman trees as well as the blocksize from BitStream
*bs*; essentially this starts reading into a next block of symbols.
"""
for i in range(len(self.__trees)):
self.__trees[i] = Huffman.read_tree(bs, Sound.MAXCODEWIDTH,
Sound.NUMCODES)
self.__syms_to_read = bs.read_bits(15)
def read_symbol(self, bs, model):
"""
Read a symbol from BitStream *bs* using the Huffman tree for model
*model*.
"""
if self.__syms_to_read == 0:
self._read_trees(bs)
self.__syms_to_read -= 1
return self.__trees[model].read_symbol(bs)
def classinit_sound_quantizer(cls):
"""
Decorator that adds the static quantizer table to class *cls*.
"""
cls._quantizer = [0] * 256
for i in range(1, 129):
# [-i] is equivalent to [256 - i]
cls._quantizer[-i] = cls._quantizer[i] = i.bit_length()
return cls
@classinit_sound_quantizer
class Channel:
"""
Decompression parameters and methods for a single audio channel.
"""
def __init__(self, symreader, channel_idx):
"""
Initialize a channel with index *channel_idx*, using symbol
reader *symreader* to fetch new symbols.
"""
self.__symreader = symreader
self.__model_base_idx = 3 * channel_idx
self.__pred_dif_cnt = [0] * 2
self.__last_pred_dif_cnt = [0] * 2
self.__rar_dif_cnt = [0] * 4
self.__rar_coeff = [0] * 4
self.__rar_dif = [0] * 9
self.__byte_count = 0
self.__last_sample = 0
self.__last_delta = 0
self.__adapt_model_cnt = 0
self.__adapt_model_use = 0
self.__get_state = 0
self.__get_code = 0
def _get_symbol(self, bs):
"""
Get next symbol from BitStream *bs*.
"""
model = self.__get_state << 1
if model == 0:
model += self.__adapt_model_use
model += self.__model_base_idx
return self.__symreader.read_symbol(bs, model)
def get(self, bs):
"""
Get next sample, reading from BitStream *bs* if necessary.
"""
if self.__get_state != 2:
self.__get_code = self._get_symbol(bs)
if self.__get_code == Sound.TYPECODE:
return AceMode.read_from(bs)
if self.__get_state == 0:
if self.__get_code >= Sound.RUNLENCODES:
value = self.__get_code - Sound.RUNLENCODES
self.__adapt_model_cnt = \
(self.__adapt_model_cnt * 7 >> 3) + value
if self.__adapt_model_cnt > 40:
self.__adapt_model_use = 1
else:
self.__adapt_model_use = 0
else:
self.__get_state = 2
elif self.__get_state == 1:
value = self.__get_code
self.__get_state = 0
if self.__get_state == 2:
if self.__get_code == 0:
self.__get_state = 1
else:
self.__get_code -= 1
value = 0
if value & 1:
return 255 - (value >> 1)
else:
return value >> 1
def rar_predict(self):
if self.__pred_dif_cnt[0] > self.__pred_dif_cnt[1]:
return self.__last_sample
else:
return self._get_predicted_sample()
def rar_adjust(self, sample):
self.__byte_count += 1
pred_sample = self._get_predicted_sample()
pred_dif = c_schar(pred_sample - sample) << 3
self.__rar_dif[0] += abs(pred_dif - self.__rar_dif_cnt[0])
self.__rar_dif[1] += abs(pred_dif + self.__rar_dif_cnt[0])
self.__rar_dif[2] += abs(pred_dif - self.__rar_dif_cnt[1])
self.__rar_dif[3] += abs(pred_dif + self.__rar_dif_cnt[1])
self.__rar_dif[4] += abs(pred_dif - self.__rar_dif_cnt[2])
self.__rar_dif[5] += abs(pred_dif + self.__rar_dif_cnt[2])
self.__rar_dif[6] += abs(pred_dif - self.__rar_dif_cnt[3])
self.__rar_dif[7] += abs(pred_dif + self.__rar_dif_cnt[3])
self.__rar_dif[8] += abs(pred_dif)
self.__last_delta = c_schar(sample - self.__last_sample)
self.__pred_dif_cnt[0] += self._quantizer[pred_dif >> 3]
self.__pred_dif_cnt[1] += self._quantizer[self.__last_sample-sample]
self.__last_sample = sample
if self.__byte_count & 0x1F == 0:
min_dif = 0xFFFF
for i in reversed(range(9)):
if self.__rar_dif[i] <= min_dif:
min_dif = self.__rar_dif[i]
min_dif_pos = i
self.__rar_dif[i] = 0
if min_dif_pos != 8:
i = min_dif_pos >> 1
if min_dif_pos & 1 == 0:
if self.__rar_coeff[i] >= -16:
self.__rar_coeff[i] -= 1
else:
if self.__rar_coeff[i] <= 16:
self.__rar_coeff[i] += 1
if self.__byte_count & 0xFF == 0:
for i in range(2):
self.__pred_dif_cnt[i] -= self.__last_pred_dif_cnt[i]
self.__last_pred_dif_cnt[i] = self.__pred_dif_cnt[i]
self.__rar_dif_cnt[3] = self.__rar_dif_cnt[2]
self.__rar_dif_cnt[2] = self.__rar_dif_cnt[1]
self.__rar_dif_cnt[1] = self.__last_delta - self.__rar_dif_cnt[0]
self.__rar_dif_cnt[0] = self.__last_delta
def _get_predicted_sample(self):
return c_uchar((8 * self.__last_sample + \
self.__rar_coeff[0] * self.__rar_dif_cnt[0] + \
self.__rar_coeff[1] * self.__rar_dif_cnt[1] + \
self.__rar_coeff[2] * self.__rar_dif_cnt[2] + \
self.__rar_coeff[3] * self.__rar_dif_cnt[3]) >> 3)
RUNLENCODES = 32
TYPECODE = 256 + RUNLENCODES
NUMCODES = 256 + RUNLENCODES + 1
MAXCODEWIDTH = 10
NUMCHANNELS = (1, 2, 3, 3)
USECHANNELS = ((0, 0, 0, 0),
(0, 1, 0, 1),
(0, 1, 0, 2),
(1, 0, 2, 0))
def __init__(self):
self.__mode = None
self.__channels = None
def reinit(self, mode):
"""
Reinitialize the SOUND decompression engine.
Reset all data dependent state to initial values.
"""
self.__mode = mode - ACE.MODE_SOUND_8
num_channels = Sound.NUMCHANNELS[self.__mode]
num_models = num_channels * 3
sr = Sound.SymbolReader(num_models)
self.__channels = [self.Channel(sr, i) for i in range(num_channels)]
def read(self, bs, want_size):
"""
Read a block of SOUND compressed data from BitStream *bs*.
Reading will stop when *want_size* output bytes can be provided,
or when a block ends, i.e. when a mode instruction is found.
Returns a tuple of the output byte-like and the mode instruction.
"""
assert want_size > 0
chunk = []
next_mode = None
for i in range(want_size & 0xFFFFFFFC):
channel = Sound.USECHANNELS[self.__mode][i % 4]
value = self.__channels[channel].get(bs)
if isinstance(value, AceMode):
next_mode = value
break
sample = c_uchar(value + self.__channels[channel].rar_predict())
chunk.append(sample)
self.__channels[channel].rar_adjust(c_schar(sample))
return (chunk, next_mode)
class Pic:
"""
ACE 2.0 PIC mode decompression engine.
Two-dimensional pixel value predictor over Huffman encoding, resulting in a
higher compression ratio for uncompressed picture data.
"""
class ErrContext:
"""
A prediction error context.
"""
def __init__(self):
self.used_counter = 0
self.predictor_number = 0
self.average_counter = 4
self.error_counters = [0] * 4
class ErrModel:
"""
A prediction error model comprising of N error contexts.
"""
N = 365
def __init__(self):
self.contexts = [Pic.ErrContext() for _ in range(Pic.ErrModel.N)]
def classinit_pic_dif_bit_width(cls):
"""
Decorator that adds the PIC dif_bit_width static table to *cls*.
"""
cls._dif_bit_width = []
for i in range(0, 128):
cls._dif_bit_width.append((2 * i).bit_length())
for i in range(-128, 0):
cls._dif_bit_width.append((- 2 * i - 1).bit_length())
return cls
def classinit_pic_quantizers(cls):
"""
Decorator that adds the PIC quantizer static tables to *cls*.
"""
cls._quantizer = []
cls._quantizer9 = []
cls._quantizer81 = []
for i in range(-255, -20):
cls._quantizer.append(-4)
for i in range(-20, -6):
cls._quantizer.append(-3)
for i in range(-6, -2):
cls._quantizer.append(-2)
for i in range(-2, 0):
cls._quantizer.append(-1)
cls._quantizer.append(0)
for i in range(1, 3):
cls._quantizer.append(1)
for i in range(3, 7):
cls._quantizer.append(2)
for i in range(7, 21):
cls._quantizer.append(3)
for i in range(21, 256):
cls._quantizer.append(4)
for q in cls._quantizer:
cls._quantizer9.append(9 * q)
cls._quantizer81.append(81 * q)
return cls
@classinit_pic_dif_bit_width
@classinit_pic_quantizers
class PixelDecoder:
_producers = []
@classmethod
def register(cls, othercls):
cls._producers.append(othercls)
return othercls
@classmethod
def read_from(cls, bs):
"""
Read a pixel decoder identifier from BitStream *bs* and return
the appropriate PixelDecoder instance.
"""
try:
return cls._producers[bs.read_bits(2)]()
except IndexError:
raise CorruptedArchiveError("Unknown producer requested")
def shift_pixels(self):
"""
Shift pixels to the left to prepare for the next column.
C A D
B X
"""
self._pixel_c = self._pixel_a
self._pixel_a = self._pixel_d
self._pixel_b = self._pixel_x
def get_context(self):
"""
Calculate the error context to use based on the differences
between the neighbouring pixels D-A, A-C and C-B:
C A D
B X
"""
ctx = self._quantizer81[255 + self._pixel_d - self._pixel_a] + \
self._quantizer9 [255 + self._pixel_a - self._pixel_c] + \
self._quantizer [255 + self._pixel_c - self._pixel_b]
return abs(ctx)
def _predict(self, use_predictor):
"""
With X being the current position, the predictors use the pixels
above (A), to the left (B) and in the corner (C):
C A D
B X
"""
if use_predictor == 0:
return self._pixel_a
elif use_predictor == 1:
return self._pixel_b
elif use_predictor == 2:
return (self._pixel_a + self._pixel_b) >> 1
elif use_predictor == 3:
return c_uchar(self._pixel_a + self._pixel_b - self._pixel_c)
def update_pixel_x(self, bs, context):
"""
Read the next data point from BitStream *bs* and store the
resulting pixel X based on ErrContext *context*.
"""
context.used_counter += 1
r = c_div(context.average_counter, context.used_counter)
epsilon = bs.read_golomb_rice(r.bit_length(), signed=True)
predicted = self._predict(context.predictor_number)
self._pixel_x = c_uchar(predicted + epsilon)
context.average_counter += abs(epsilon)
if context.used_counter == 128:
context.used_counter >>= 1
context.average_counter >>= 1
for i in range(len(context.error_counters)):
context.error_counters[i] += \
self._dif_bit_width[self._pixel_x - self._predict(i)]
if i == 0 or context.error_counters[i] < \
context.error_counters[best_predictor]:
best_predictor = i
context.predictor_number = best_predictor
if any([ec > 0x7F for ec in context.error_counters]):
for i in range(len(context.error_counters)):
context.error_counters[i] >>= 1
@PixelDecoder.register
class PixelDecoder0(PixelDecoder):
def __init__(self):
self._pixel_a = 0
self._pixel_b = 0
self._pixel_c = 0
self._pixel_x = 0
def update_pixel_d(self, thisplane_d, refplane_d):
self._pixel_d = thisplane_d
def produce(self, refplane_x):
return self._pixel_x
class DifferentialPixelDecoder(PixelDecoder):
def __init__(self):
self._pixel_a = 128
self._pixel_b = 128
self._pixel_c = 128
self._pixel_x = 128
@PixelDecoder.register
class PixelDecoder1(DifferentialPixelDecoder):
def update_pixel_d(self, thisplane_d, refplane_d):
self._pixel_d = c_uchar(128 + thisplane_d - refplane_d)
def produce(self, refplane_x):
return c_uchar(self._pixel_x + refplane_x - 128)
@PixelDecoder.register
class PixelDecoder2(DifferentialPixelDecoder):
def update_pixel_d(self, thisplane_d, refplane_d):
self._pixel_d = c_uchar(128 + thisplane_d - (refplane_d * 11 >> 4))
def produce(self, refplane_x):
return c_uchar(self._pixel_x + (refplane_x * 11 >> 4) - 128)
def __init__(self):
pass
def reinit(self, bs):
"""
Reinitialize the PIC decompression engine.
Read width and planes from BitStream *bs* and reset all data dependent
state to initial values.
Note that width does not need to be a multiple of planes.
"""
self.__width = bs.read_golomb_rice(12)
self.__planes = bs.read_golomb_rice(2)
self.__errmodel_plane0 = self.ErrModel()
self.__errmodel_plane1toN = self.ErrModel()
self.__prevrow = [0] * (self.__width + self.__planes)
self.__leftover = []
def _row(self, bs):
"""
Decompress a row of pixels.
"""
# NOTE
# Some indices into row and self.__prevrow are outside of the
# expected range 0..width, as indicated below. Additionally, when
# processing the first row, self.__prevrow is all zeroes.
# Furthermore, self.__width is not necessarily a multiple of
# self.__planes.
row = [0] * (self.__width + self.__planes)
for plane in range(self.__planes):
if plane == 0:
errmodel = self.__errmodel_plane0
decoder = Pic.PixelDecoder0()
else:
errmodel = self.__errmodel_plane1toN
decoder = Pic.PixelDecoder.read_from(bs)
# plane-1 is -1 for first plane
decoder.update_pixel_d(self.__prevrow[plane],
self.__prevrow[plane - 1])
for col in range(plane, self.__width, self.__planes):
decoder.shift_pixels()
# col+self.__planes is > width for last col in plane
decoder.update_pixel_d(self.__prevrow[col + self.__planes],
self.__prevrow[col + self.__planes - 1])
context = errmodel.contexts[decoder.get_context()]
decoder.update_pixel_x(bs, context)
# col-1 is -1 for first col in first plane
row[col] = decoder.produce(row[col - 1])
self.__prevrow = row
return row[:self.__width]
def read(self, bs, want_size):
"""
Read a block of PIC compressed data from BitStream *bs*.
Reading will stop when *want_size* output bytes can be provided,
or when a block ends, i.e. when a mode instruction is found.
Returns a tuple of the output byte-like and the mode instruction.
"""
assert want_size > 0
chunk = []
next_mode = None
if len(self.__leftover) > 0:
chunk.extend(self.__leftover)
self.__leftover = []
while len(chunk) < want_size:
if bs.read_bits(1) == 0:
next_mode = AceMode.read_from(bs)
break
data = self._row(bs)
n = min(want_size - len(chunk), len(data))
if n == len(data):
chunk.extend(data)
else:
chunk.extend(data[0:n])
self.__leftover = data[n:]
return (chunk, next_mode)
class ACE:
"""
Core decompression engine for ACE compression up to version 2.0.
"""
MODE_LZ77 = 0 # LZ77
MODE_LZ77_DELTA = 1 # LZ77 after byte reordering
MODE_LZ77_EXE = 2 # LZ77 after patching JMP/CALL targets
MODE_SOUND_8 = 3 # 8 bit sound compression
MODE_SOUND_16 = 4 # 16 bit sound compression
MODE_SOUND_32A = 5 # 32 bit sound compression, variant 1
MODE_SOUND_32B = 6 # 32 bit sound compression, variant 2
MODE_PIC = 7 # picture compression
MODE_STRINGS = ('LZ77', 'LZ77_DELTA', 'LZ77_EXE',
'SOUND_8', 'SOUND_16', 'SOUND_32A', 'SOUND_32B',
'PIC')
@staticmethod
def mode_str(mode):
try:
return ACE.MODE_STRINGS[mode]
except IndexError:
return '?'
@staticmethod
def decompress_comment(buf):
"""
Decompress an ACE MAIN or FILE comment from bytes *buf* and return the
decompressed bytes.
"""
bs = BitStream(io.BytesIO(buf))
want_size = bs.read_bits(15)
huff_tree = Huffman.read_tree(bs, LZ77.MAXCODEWIDTH, LZ77.NUMMAINCODES)
comment = []
htab = [0] * 511
while len(comment) < want_size:
if len(comment) > 1:
hval = comment[-1] + comment[-2]
source_pos = htab[hval]
htab[hval] = len(comment)
else:
source_pos = 0
code = huff_tree.read_symbol(bs)
if code < 256:
comment.append(code)
else:
for i in range(code - 256 + 2):
comment.append(comment[source_pos + i])
return bytes(comment)
def __init__(self):
self.__lz77 = LZ77()
self.__sound = Sound()
self.__pic = Pic()
def decompress_stored(self, f, filesize, dicsize):
"""
Decompress data compressed using the store method from file-like-object
*f* containing compressed bytes that will be decompressed to *filesize*
bytes. Decompressed data will be yielded in blocks of undefined size
upon availability. Empty files will return without yielding anything.
"""
self.__lz77.dic_setsize(dicsize)
producedsize = 0
while producedsize < filesize:
wantsize = min(filesize - producedsize, FILE_BLOCKSIZE)
outchunk = f.read(wantsize)
if len(outchunk) == 0:
raise CorruptedArchiveError("Truncated stored file")
self.__lz77.dic_register(outchunk)
yield outchunk
producedsize += len(outchunk)
def decompress_lz77(self, f, filesize, dicsize):
"""
Decompress data compressed using the ACE 1.0 legacy LZ77 method from
file-like-object *f* containing compressed bytes that will be
decompressed to *filesize* bytes. Decompressed data will be yielded
in blocks of undefined size upon availability.
"""
self.__lz77.dic_setsize(dicsize)
self.__lz77.reinit()
bs = BitStream(f)
producedsize = 0
while producedsize < filesize:
outchunk, next_mode = self.__lz77.read(bs, filesize)
if next_mode:
raise CorruptedArchiveError("LZ77.TYPECODE in ACE 1.0 LZ77")
yield bytes(outchunk)
producedsize += len(outchunk)
def decompress_blocked(self, f, filesize, dicsize):
"""
Decompress data compressed using the ACE 2.0 blocked method from
file-like-object *f* containing compressed bytes that will be
decompressed to *filesize* bytes. Decompressed data will be yielded
in blocks of undefined size upon availability.
"""
bs = BitStream(f)
self.__lz77.dic_setsize(dicsize)
self.__lz77.reinit()
# LZ77_EXE
exe_leftover = []
# LZ77_DELTA
last_delta = 0
next_mode = None
mode = AceMode(ACE.MODE_LZ77)
producedsize = 0
while producedsize < filesize:
if next_mode != None:
if mode.mode != next_mode.mode:
if next_mode.mode in (ACE.MODE_SOUND_8,
ACE.MODE_SOUND_16,
ACE.MODE_SOUND_32A,
ACE.MODE_SOUND_32B):
self.__sound.reinit(next_mode.mode)
elif next_mode.mode == ACE.MODE_PIC:
self.__pic.reinit(bs)
mode = next_mode
next_mode = None
outchunk = []
if mode.mode == ACE.MODE_LZ77_DELTA:
# Preprocessor that rearranges chunks of data and calculates
# differences between byte values, resulting in a higher
# LZ77 compression ratio for some inputs.
delta = []
while len(delta) < mode.delta_len:
chunk, nm = self.__lz77.read(bs,
mode.delta_len - len(delta))
if len(delta) == 0:
# avoid costly copy
delta = chunk
else:
delta.extend(chunk)
if nm != None:
if next_mode:
raise CorruptedArchiveError("DELTA clobbers mode")
next_mode = nm
if len(delta) == 0:
break
if len(delta) == 0 and next_mode != None:
continue
for i in range(len(delta)):
delta[i] = c_uchar(delta[i] + last_delta)
last_delta = delta[i]
delta_plane = 0
delta_plane_pos = 0
delta_plane_size = mode.delta_len // mode.delta_dist
while delta_plane_pos < delta_plane_size:
while delta_plane < mode.delta_len:
outchunk.append(delta[delta_plane + delta_plane_pos])
delta_plane += delta_plane_size
delta_plane = 0
delta_plane_pos += 1
# end of ACE.MODE_LZ77_DELTA
elif mode.mode in (ACE.MODE_LZ77, ACE.MODE_LZ77_EXE):
if len(exe_leftover) > 0:
outchunk.extend(exe_leftover)
exe_leftover = []
chunk, next_mode = self.__lz77.read(bs,
filesize - producedsize - len(outchunk))
outchunk.extend(chunk)
if mode.mode == ACE.MODE_LZ77_EXE:
# Preprocessor that adjusts target addresses of
# x86 JMP and CALL instructions in order to achieve a
# higher LZ77 compression ratio for executables.
it = iter(range(len(outchunk)))
for i in it:
if i + 4 >= len(outchunk):
break
if outchunk[i] == 0xE8: # CALL rel16/rel32
pos = producedsize + i
if mode.exe_mode == 0:
# rel16
#assert i + 2 < len(outchunk)
rel16 = outchunk[i+1] + (outchunk[i+2] << 8)
rel16 = (rel16 - pos) & 0xFFFF
outchunk[i+1] = rel16 & 0xFF
outchunk[i+2] = (rel16 >> 8) & 0xFF
next(it); next(it)
else:
# rel32
#assert i + 4 < len(outchunk)
rel32 = outchunk[i+1] + \
(outchunk[i+2] << 8) + \
(outchunk[i+3] << 16) + \
(outchunk[i+4] << 24)
rel32 = (rel32 - pos) & 0xFFFFFFFF
outchunk[i+1] = rel32 & 0xFF
outchunk[i+2] = (rel32 >> 8) & 0xFF
outchunk[i+3] = (rel32 >> 16) & 0xFF
outchunk[i+4] = (rel32 >> 24) & 0xFF
next(it); next(it); next(it); next(it)
elif outchunk[i] == 0xE9: # JMP rel16/rel32
pos = producedsize + i
# rel16
#assert i + 2 < len(outchunk)
rel16 = outchunk[i+1] + (outchunk[i+2] << 8)
rel16 = (rel16 - pos) & 0xFFFF
outchunk[i+1] = rel16 & 0xFF
outchunk[i+2] = (rel16 >> 8) & 0xFF
next(it); next(it)
# store max 4 bytes for next loop; this can happen when
# changing between different exe modes after the opcode
# but before completing the machine instruction
for i in it:
#assert i + 4 >= len(outchunk)
if outchunk[i] == 0xE8 or outchunk[i] == 0xE9:
exe_leftover = outchunk[i:]
outchunk = outchunk[:i]
# end of ACE.MODE_LZ77_EXE
# end of ACE.MODE_LZ77 or ACE.MODE_LZ77_EXE
elif mode.mode in (ACE.MODE_SOUND_8, ACE.MODE_SOUND_16,
ACE.MODE_SOUND_32A, ACE.MODE_SOUND_32B):
outchunk, next_mode = self.__sound.read(bs,
filesize - producedsize)
self.__lz77.dic_register(outchunk)
# end of ACE.MODE_SOUND_*
elif mode.mode == ACE.MODE_PIC:
outchunk, next_mode = self.__pic.read(bs,
filesize - producedsize)
self.__lz77.dic_register(outchunk)
# end of ACE.MODE_PIC
else:
raise CorruptedArchiveError("unknown mode: %s" % mode)
yield bytes(outchunk)
producedsize += len(outchunk)
# end of block loop
return producedsize
class Header:
"""
Base class for all ACE file format headers.
Header classes are dumb by design and only serve as fancy structs.
"""
MAGIC = b'**ACE**'
TYPE_MAIN = 0
TYPE_FILE32 = 1
TYPE_RECOVERY32 = 2
TYPE_FILE64 = 3
TYPE_RECOVERY64A = 4
TYPE_RECOVERY64B = 5
TYPE_STRINGS = ('MAIN', 'FILE32', 'RECOVERY32',
'FILE64', 'RECOVERY64A', 'RECOVERY64B')
FLAG_ADDSIZE = 1 << 0 # 1 iff addsize field present MFR
FLAG_COMMENT = 1 << 1 # 1 iff comment present MF-
FLAG_64BIT = 1 << 2 # 1 iff 64bit addsize field -FR
FLAG_V20FORMAT = 1 << 8 # 1 iff ACE 2.0 format M--
FLAG_SFX = 1 << 9 # 1 iff self extracting archive M--
FLAG_LIMITSFXJR = 1 << 10 # 1 iff dict size limited to 256K M--
FLAG_NTSECURITY = 1 << 10 # 1 iff NTFS security data present -F-
FLAG_MULTIVOLUME = 1 << 11 # 1 iff archive has multiple volumes M--
FLAG_ADVERT = 1 << 12 # 1 iff advert string present M--
FLAG_CONTPREV = 1 << 12 # 1 iff continued from previous volume -F-
FLAG_RECOVERY = 1 << 13 # 1 iff recovery record present M--
FLAG_CONTNEXT = 1 << 13 # 1 iff continued in next volume -F-
FLAG_LOCKED = 1 << 14 # 1 iff archive is locked M--
FLAG_PASSWORD = 1 << 14 # 1 iff password encrypted -F-
FLAG_SOLID = 1 << 15 # 1 iff archive is solid MF-
FLAG_STRINGS_M = ('ADDSIZE', 'COMMENT', '4', '8',
'16', '32', '64', '128',
'V20FORMAT', 'SFX', 'LIMITSFXJR', 'MULTIVOLUME',
'ADVERT', 'RECOVERY', 'LOCKED', 'SOLID')
FLAG_STRINGS_F = ('ADDSIZE', 'COMMENT', '64BIT', '8',
'16', '32', '64', '128',
'256', '512', 'NTSECURITY', '2048',
'CONTPREV', 'CONTNEXT', 'PASSWORD', 'SOLID')
FLAG_STRINGS_R = ('ADDSIZE', '2', '64BIT', '8',
'16', '32', '64', '128',
'256', '512', '1024', '2048',
'4096', '8192', '16384', '32768')
FLAG_STRINGS_BYTYPE = (FLAG_STRINGS_M, FLAG_STRINGS_F, FLAG_STRINGS_R,
FLAG_STRINGS_F, FLAG_STRINGS_R, FLAG_STRINGS_R)
HOST_MSDOS = 0
HOST_OS2 = 1
HOST_WIN32 = 2
HOST_UNIX = 3
HOST_MAC_OS = 4
HOST_WIN_NT = 5
HOST_PRIMOS = 6
HOST_APPLE_GS = 7
HOST_ATARI = 8
HOST_VAX_VMS = 9
HOST_AMIGA = 10
HOST_NEXT = 11
HOST_LINUX = 12
HOST_STRINGS = ('MS-DOS', 'OS/2', 'Win32', 'Unix', 'Mac OS',
'Win NT', 'Primos', 'Apple GS', 'ATARI', 'VAX VMS',
'AMIGA', 'NeXT', 'Linux')
COMP_STORED = 0
COMP_LZ77 = 1
COMP_BLOCKED = 2
COMP_STRINGS = ('stored', 'lz77', 'blocked')
QUAL_NONE = 0
QUAL_FASTEST = 1
QUAL_FAST = 2
QUAL_NORMAL = 3
QUAL_GOOD = 4
QUAL_BEST = 5
QUAL_STRINGS = ('store', 'fastest', 'fast', 'normal', 'good', 'best')
# winnt.h
ATTR_READONLY = 0x00000001
ATTR_HIDDEN = 0x00000002
ATTR_SYSTEM = 0x00000004
ATTR_VOLUME_ID = 0x00000008
ATTR_DIRECTORY = 0x00000010
ATTR_ARCHIVE = 0x00000020
ATTR_DEVICE = 0x00000040
ATTR_NORMAL = 0x00000080
ATTR_TEMPORARY = 0x00000100
ATTR_SPARSE_FILE = 0x00000200
ATTR_REPARSE_POINT = 0x00000400
ATTR_COMPRESSED = 0x00000800
ATTR_OFFLINE = 0x00001000
ATTR_NOT_CONTENT_INDEXED = 0x00002000
ATTR_ENCRYPTED = 0x00004000
ATTR_INTEGRITY_STREAM = 0x00008000
ATTR_VIRTUAL = 0x00010000
ATTR_NO_SCRUB_DATA = 0x00020000
ATTR_EA = 0x00040000
ATTR_STRINGS = ('READONLY', 'HIDDEN', 'SYSTEM', 'VOLUME_ID',
'DIRECTORY', 'ARCHIVE', 'DEVICE', 'NORMAL',
'TEMPORARY', 'SPARSE_FILE',
'REPARSE_POINT', 'COMPRESSED',
'OFFLINE', 'NOT_CONTENT_INDEXED',
'ENCRYPTED', 'INTEGRITY_STREAM',
'VIRTUAL', 'NO_SCRUB_DATA', 'EA')
@staticmethod
def _format_bitfield(strings, field):
labels = []
for i in range(field.bit_length()):
bit = 1 << i
if field & bit == bit:
try:
labels.append(strings[i])
except IndexError:
labels.append(str(bit))
return '|'.join(labels)
def __init__(self, crc, size, type, flags):
self.hdr_crc = crc # uint16 header crc without crc,sz
self.hdr_size = size # uint16 header size without crc,sz
self.hdr_type = type # uint8
self.hdr_flags = flags # uint16
def __str__(self):
return """header
hdr_crc 0x%04x
hdr_size %i
hdr_type 0x%02x %s
hdr_flags 0x%04x %s""" % (
self.hdr_crc,
self.hdr_size,
self.hdr_type, self.hdr_type_str,
self.hdr_flags, self.hdr_flags_str)
def flag(self, flag):
return self.hdr_flags & flag == flag
@property
def hdr_type_str(self):
try:
return Header.TYPE_STRINGS[self.hdr_type]
except IndexError:
return '?'
@property
def hdr_flags_str(self):
try:
strings = self.FLAG_STRINGS_BYTYPE[self.hdr_type]
return self._format_bitfield(strings, self.hdr_flags)
except IndexError:
return '?'
class UnknownHeader(Header):
pass
class MainHeader(Header):
def __init__(self, *args):
super().__init__(*args)
self.magic = None # uint8[7] **ACE**
self.eversion = None # uint8 extract version
self.cversion = None # uint8 creator version
self.host = None # uint8 platform
self.volume = None # uint8 volume number
self.datetime = None # uint32 date/time in MS-DOS format
self.reserved1 = None # uint8[8]
self.advert = b'' # [uint8] optional
self.comment = b'' # [uint16] optional, compressed
self.reserved2 = None # [?] optional
def __str__(self):
return super().__str__() + """
magic %r
eversion %i %s
cversion %i %s
host 0x%02x %s
volume %i
datetime 0x%08x %s
reserved1 %02x %02x %02x %02x %02x %02x %02x %02x
advert %r
comment %r
reserved2 %r""" % (
self.magic,
self.eversion, self.eversion/10,
self.cversion, self.cversion/10,
self.host, self.host_str,
self.volume,
self.datetime,
_dt_fromdos(self.datetime).strftime('%Y-%m-%d %H:%M:%S'),
self.reserved1[0], self.reserved1[1],
self.reserved1[2], self.reserved1[3],
self.reserved1[4], self.reserved1[5],
self.reserved1[6], self.reserved1[7],
self.advert,
self.comment,
self.reserved2)
@property
def host_str(self):
try:
return Header.HOST_STRINGS[self.host]
except IndexError:
return '?'
class FileHeader(Header):
def __init__(self, *args):
super().__init__(*args)
self.packsize = None # uint32|64 packed size
self.origsize = None # uint32|64 original size
self.datetime = None # uint32 ctime
self.attribs = None # uint32 file attributes
self.crc32 = None # uint32 checksum over compressed file
self.comptype = None # uint8 compression type
self.compqual = None # uint8 compression quality
self.params = None # uint16 decompression parameters
self.reserved1 = None # uint16
self.filename = None # [uint16]
self.comment = b'' # [uint16] optional, compressed
self.ntsecurity = b'' # [uint16] optional
self.reserved2 = None # ?
self.dataoffset = None # position of data after hdr
def __str__(self):
return super().__str__() + """
packsize %i
origsize %i
datetime 0x%08x %s
attribs 0x%08x %s
crc32 0x%08x
comptype 0x%02x %s
compqual 0x%02x %s
params 0x%04x
reserved1 0x%04x
filename %r
comment %r
ntsecurity %r
reserved2 %r""" % (
self.packsize,
self.origsize,
self.datetime,
_dt_fromdos(self.datetime).strftime('%Y-%m-%d %H:%M:%S'),
self.attribs, self.attribs_str,
self.crc32,
self.comptype, self.comptype_str,
self.compqual, self.compqual_str,
self.params,
self.reserved1,
self.filename,
self.comment,
self.ntsecurity,
self.reserved2)
def attrib(self, attrib):
return self.attribs & attrib == attrib
@property
def attribs_str(self):
return self._format_bitfield(Header.ATTR_STRINGS, self.attribs)
@property
def comptype_str(self):
try:
return Header.COMP_STRINGS[self.comptype]
except IndexError:
return '?'
@property
def compqual_str(self):
try:
return Header.QUAL_STRINGS[self.compqual]
except IndexError:
return '?'
class RecoveryHeader(Header):
def __init__(self, *args):
super().__init__(*args)
# R32 R64A R64B
self.rcvrsize = None # uint32 uint64 uint64 recovery data size
self.magic = None # uint8[7] **ACE**
self.relstart = None # uint32 uint64 uint64 ?
self.cluster = None # uint32 uint32 - ?
self.sectors = None # - - uint16 ?
self.spc = None # - - uint16 ?
self.clustersize = None # uint32 uint32 uint32 ?
self.rcvrcrc = None # uint16 uint16 - recovery data crc
def __str__(self):
segments = [super().__str__()]
segments.append("""
rcvrsize %i
magic %r
relstart %i""" % (
self.rcvrsize,
self.magic,
self.relstart))
if self.hdr_type in (Header.TYPE_RECOVERY32,
Header.TYPE_RECOVERY64A):
segments.append("""
cluster %i
clustersize %i
rcvrcrc 0x%02x""" % (
self.cluster,
self.clustersize,
self.rcvrcrc))
elif self.hdr_type == Header.TYPE_RECOVERY64B:
segments.append("""
sectors %i
spc %i
clustersize %i""" % (
self.sectors,
self.spc,
self.clustersize))
return ''.join(segments)
class AceError(Exception):
"""
Base class for all :mod:`acefile` exceptions.
"""
pass
class MainHeaderNotFoundError(AceError):
"""
The main ACE header marked by the magic bytes ``**ACE**`` could not be
found.
Either the *search* argument was to small or the archive is not an ACE
format archive.
"""
pass
class MultiVolumeArchiveError(AceError):
"""
A multi-volume archive was expected but a normal archive was found, or
mismatching volumes were provided, or while reading a member from a
multi-volume archive, the member headers indicate that the member
continues in the next volume, but no next volume was found or provided.
"""
pass
class CorruptedArchiveError(AceError):
"""
Archive is corrupted. Either a header or data CRC check failed, an invalid
value was read from the archive or the archive is truncated.
"""
pass
class EncryptedArchiveError(AceError):
"""
Archive member is encrypted but either no password was provided, or
decompression failed with the given password.
Also raised when processing an encrypted solid archive member out of order,
when any previous archive member uses a different password than the archive
member currently being accessed.
.. note::
Due to the lack of a password verifier in the ACE file format, there is
no straightforward way to distinguish a wrong password from a corrupted
archive. If the CRC check of an encrypted archive member fails or an
:class:`CorruptedArchiveError` is encountered during decompression, it
is assumed that the password was wrong and as a consequence,
:class:`EncryptedArchiveError` is raised.
"""
pass
class UnknownCompressionMethodError(AceError):
"""
Data was compressed using an unknown compression method and therefore
cannot be decompressed using this implementation. This should not happen
for ACE 1.0 or ACE 2.0 archives since this implementation implements all
existing compression methods.
"""
pass
class AceMember:
"""
Represents a single archive member, potentially spanning multiple
archive volumes.
:class:`AceMember` is not directly instantiated; instead, instances are
returned by :meth:`AceArchive.getmember` and :meth:`AceArchive.getmembers`.
"""
# https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247
if platform.system() == 'Windows':
RESERVED_NAMES = ('CON', 'PRN', 'AUX', 'NUL', 'COM1', 'COM2', 'COM3',
'COM4', 'COM5', 'COM6', 'COM7', 'COM8', 'COM9',
'LPT1', 'LPT2', 'LPT3', 'LPT4', 'LPT5', 'LPT6',
'LPT7', 'LPT8', 'LPT9')
else:
RESERVED_NAMES = ()
RESERVED_CHARS = ':<>"?*|' + ''.join([chr(x) for x in range(1,32)])
TRANSLATION_TAB = str.maketrans(dict.fromkeys(RESERVED_CHARS))
@staticmethod
def _sanitize_filename(filename):
"""
Decode and sanitize filename for security and platform independence.
Returns either a sanitized relative path, or an empty string.
This python implementation was not vulnerable to CVE-2018-20250, but we
include a test vector to make sure anyway.
While the author believes this sanitization function to be safe, it is
entirely possible that it is not. For maximum safety against path
traversal attacks, for instance when unpacking malicious code, you may
want to ignore the filenames in the archive headers and instead
generate your own filename for each archive member.
>>> AceMember._sanitize_filename(b'a.exe\\0b.txt')
'a.exe'
>>> AceMember._sanitize_filename(b'\\\\etc\\\\foo/bar\\\\baz.txt')
'etc/foo/bar/baz.txt'
>>> AceMember._sanitize_filename(b'a/b/../b/.//.././c/.//../d/file.txt')
'a/d/file.txt'
>>> AceMember._sanitize_filename(b'/etc/passwd')
'etc/passwd'
>>> AceMember._sanitize_filename(b'.././.././.././.././../etc/passwd')
'etc/passwd'
>>> AceMember._sanitize_filename(b'C:\\\\Windows\\\\foo.exe')
'C/Windows/foo.exe'
>>> AceMember._sanitize_filename(b'\\\\\\\\server\\\\share\\\\file')
'server/share/file'
>>> AceMember._sanitize_filename(b'\\\\\\\\.\\\\CdRom0')
'CdRom0'
>>> AceMember._sanitize_filename(b'\\\\\\\\?\\\\raw\\\\path')
'raw/path'
>>> AceMember._sanitize_filename(b'hello\x05world')
'helloworld'
>>> AceMember._sanitize_filename(b'.././.././.././.././../etc/../')
''
>>> AceMember._sanitize_filename(b'c:\\\\c:\\\\CVE-2018-20250\\\\p.lnk')
'c/c/CVE-2018-20250/p.lnk'
"""
filename = filename.decode('utf-8', errors='replace')
# treat null byte as filename terminator
nullbyte = filename.find(chr(0))
if nullbyte >= 0:
filename = filename[0:nullbyte]
# ensure path separators are consistent with current platform
if os.sep != '/':
filename = filename.replace('/', os.sep)
if os.sep != '\\':
filename = filename.replace('\\', os.sep)
# eliminate characters illegal on some platforms, including some
# characters that are relevant for path traversal attacks (i.e. colon)
filename = filename.translate(AceMember.TRANSLATION_TAB)
# first eliminate all /./, foo/../ and similar sequences, then remove
# all remaining .. labels in order to avoid path traversal attacks but
# still allow a safe subset of dot syntax in the filename
filename = os.path.normpath(filename)
escsep = re.escape(os.sep)
pattern = r'(^|%s)(?:\.\.(?:%s|$))+' % (escsep, escsep)
filename = re.sub(pattern, r'\1', filename)
# remove leading path separators to ensure a relative path
filename = filename.lstrip(os.sep)
# avoid reserved file names
if filename in AceMember.RESERVED_NAMES:
return '_' + filename
return filename
def __init__(self, idx, filehdrs, f):
"""
Initialize an :class:`AceMember` object with index within archive *idx*,
initial file header *filehdr* and underlying file-like object *f*.
"""
self._idx = idx
self._file = f
self._headers = filehdrs
self.__attribs = filehdrs[0].attribs
self.__comment = filehdrs[0].comment.decode('utf-8',
errors='replace')
self.__crc32 = filehdrs[-1].crc32
self.__comptype = filehdrs[0].comptype
self.__compqual = filehdrs[0].compqual
self.__datetime = _dt_fromdos(filehdrs[0].datetime)
self.__dicsizebits = (filehdrs[0].params & 15) + 10
self.__dicsize = 1 << self.__dicsizebits
self.__raw_filename = filehdrs[0].filename
self.__filename = self._sanitize_filename(filehdrs[0].filename)
if self.__filename == '':
self.__filename = 'file%04i' % self._idx
self.__ntsecurity = filehdrs[0].ntsecurity
self.__size = filehdrs[0].origsize
self.__packsize = 0
for hdr in filehdrs:
self.__packsize += hdr.packsize
def is_dir(self):
"""
True iff :class:`AceMember` instance describes a directory.
"""
return self.attribs & Header.ATTR_DIRECTORY != 0
def is_enc(self):
"""
True iff :class:`AceMember` instance describes an encrypted archive
member.
"""
return self._headers[0].flag(Header.FLAG_PASSWORD)
def is_reg(self):
"""
True iff :class:`AceMember` instance describes a regular file.
"""
return not self.is_dir()
@property
def attribs(self):
"""
DOS/Windows file attribute bit field, as :class:`int`,
as produced by the Windows :func:`GetFileAttributes` API.
"""
return self.__attribs
@property
def comment(self):
"""
File-level comment, as :class:`str`.
If absent, empty :class:`str`.
"""
return self.__comment
@property
def comptype(self):
"""
Compression type used; one of
:data:`COMP_STORED`,
:data:`COMP_LZ77` or
:data:`COMP_BLOCKED`.
"""
return self.__comptype
@property
def compqual(self):
"""
Compression quality used; one of
:data:`QUAL_NONE`,
:data:`QUAL_FASTEST`,
:data:`QUAL_FAST`,
:data:`QUAL_NORMAL`,
:data:`QUAL_GOOD` or
:data:`QUAL_BEST`.
"""
return self.__compqual
@property
def crc32(self):
"""
ACE CRC-32 checksum of decompressed data as recorded in the archive,
as :class:`int`.
ACE CRC-32 is the bitwise inverse of standard CRC-32.
"""
return self.__crc32
@property
def datetime(self):
"""
Timestamp as recorded in the archive, as :class:`datetime.datetime`
instance.
"""
return self.__datetime
@property
def dicsize(self):
"""
LZ77 dictionary size required for extraction of this archive member
in literal symbols, ranging from 1K to 4M.
"""
return 1 << self.__dicsizebits
@property
def dicsizebits(self):
"""
LZ77 dictionary size bit length, i.e. the base-two logarithm of the
dictionary size required for extraction of this archive member.
"""
return self.__dicsizebits
@property
def filename(self):
"""
Sanitized filename, as :class:`str`, safe for use with file
operations on the current platform.
"""
return self.__filename
@property
def ntsecurity(self):
"""
NT security descriptor as :class:`bytes`, describing the owner, primary
group and discretionary access control list (DACL) of the archive
member, as produced by the Windows :func:`GetFileSecurity` API with the
:data:`OWNER_SECURITY_INFORMATION`,
:data:`GROUP_SECURITY_INFORMATION` and
:data:`DACL_SECURITY_INFORMATION` flags set.
If absent, empty :class:`bytes`.
"""
return self.__ntsecurity
@property
def packsize(self):
"""
Size before decompression (packed size).
"""
return self.__packsize
@property
def raw_filename(self):
"""
Raw, unsanitized filename, as :class:`bytes`, not safe for use with
file operations and possibly using path syntax from other platforms.
"""
return self.__raw_filename
@property
def size(self):
"""
Size after decompression (original size).
"""
return self.__size
def __str__(self):
return "member idx %i sz %i/%i type %i qual %i: %s" % (
self._idx, self.packsize, self.size,
self.comptype, self.compqual,
self.filename)
class AceVolume:
"""
Parse and represent a single archive volume.
"""
def __init__(self, file, mode='r', *, search=524288, _idx=0, _am=None):
if mode != 'r':
raise NotImplementedError("mode != 'r' not implemented")
if isinstance(file, str):
self.__file = builtins.open(file, 'rb')
self.__filename = file
else:
if not file.seekable():
raise TypeError("file must be filename or "
"seekable file-like object")
self.__file = file
self.__filename = '-'
self.__file.seek(0, 2)
self.__filesize = self.__file.tell()
self.__main_header = None
self.__file_headers = []
self.__recovery_headers = []
self.__all_headers = []
try:
self._parse_headers(search)
if self.__main_header == None:
raise CorruptedArchiveError("no main header")
except:
self.close()
raise
def close(self):
"""
Close the underlying file object for this volume.
Can safely be called multiple times.
"""
if self.__file != None:
self.__file.close()
self.__file = None
def dumpheaders(self, file=sys.stdout):
"""
Dump ACE headers in this archive volume to *file*.
"""
print("""volume
filename %s
filesize %i
headers MAIN:1 FILE:%i RECOVERY:%i others:%i""" % (
self.__filename,
self.__filesize,
len(self.__file_headers),
len(self.__recovery_headers),
len(self.__all_headers) - len(self.__file_headers) - \
len(self.__recovery_headers) - 1),
file=file)
for h in self.__all_headers:
print(h, file=file)
def file_segment_for(self, fhdr):
"""
Returns a :class:`FileSegmentIO` object for the file header *fhdr*
belonging to this volume.
"""
assert fhdr in self.__file_headers
return FileSegmentIO(self.__file, fhdr.dataoffset, fhdr.packsize)
def _next_filename(self):
"""
Derive the filename of the next volume after this one.
If the filename ends in ``.[cC]XX``, XX is incremented by 1.
Otherwise self is assumed to be the first in the series and
``.[cC]00`` is used as extension.
Returns the derived filename in two variants, upper and lower case,
to allow for finding the file on fully case-sensitive filesystems.
"""
base, ext = os.path.splitext(self.__filename)
ext = ext.lower()
if ext[:2] == '.c':
try:
n = int(ext[2:])
return (base + ('.c%02i' % (n + 1)),
base + ('.C%02i' % (n + 1)))
except ValueError:
pass
return (base + '.c00',
base + '.C00')
def try_load_next_volume(self, mode):
"""
Open the next volume following this one in a multi-volume archive
and return the instantiated :class:`AceVolume` object.
"""
for nextname in self._next_filename():
try:
return AceVolume(nextname, mode=mode, search=0)
except FileNotFoundError:
continue
return None
def _parse_headers(self, search):
"""
Parse ACE headers from self.__file. If *search* is > 0, search for
the magic bytes in the first *search* bytes of the file.
Raises MainHeaderNotFoundError if the main header could not be located.
Raises other exceptions if parsing fails for other reasons.
On success, loads all the parsed headers into self.__main_header,
self.__file_headers, self.__recovery_headers and self.__all_headers.
"""
self.__file.seek(0, 0)
buf = self.__file.read(512)
found_at_start = False
if buf[7:14] == MainHeader.MAGIC:
self.__file.seek(0, 0)
try:
self._parse_header()
found_at_start = True
except CorruptedArchiveError:
pass
if not found_at_start:
if search == 0:
raise MainHeaderNotFoundError("no ACE header at offset 0")
self.__file.seek(0, 0)
buf = self.__file.read(search)
magicpos = 7
while magicpos < search:
magicpos = buf.find(MainHeader.MAGIC, magicpos + 1, search)
if magicpos == -1:
raise MainHeaderNotFoundError(
"no ACE header within first %i bytes" % search)
self.__file.seek(magicpos - 7, 0)
try:
self._parse_header()
break
except CorruptedArchiveError:
continue
while self.__file.tell() < self.__filesize:
self._parse_header()
def _parse_header(self):
"""
Parse a single header from self.__file at the current file position.
Raises CorruptedArchiveError if the header cannot be parsed.
Guarantees that no data is written to object state
if an exception is thrown, otherwise the header is added to
self.__main_header, self.__file_headers, self.__recovery_headers
and self.__all_headers.
"""
buf = self.__file.read(4)
if len(buf) < 4:
raise CorruptedArchiveError("truncated header")
hcrc, hsize = struct.unpack('<HH', buf)
buf = self.__file.read(hsize)
if len(buf) < hsize:
raise CorruptedArchiveError("truncated header")
if ace_crc16(buf) != hcrc:
raise CorruptedArchiveError("header CRC failed")
htype, hflags = struct.unpack('<BH', buf[0:3])
i = 3
if htype == Header.TYPE_MAIN:
header = MainHeader(hcrc, hsize, htype, hflags)
if header.flag(Header.FLAG_ADDSIZE):
raise CorruptedArchiveError("main header has addsize > 0")
header.magic = buf[3:10]
if header.magic != MainHeader.MAGIC:
raise CorruptedArchiveError("main header without magic")
header.eversion, \
header.cversion, \
header.host, \
header.volume, \
header.datetime = struct.unpack('<BBBBL', buf[10:18])
header.reserved1 = buf[18:26]
i = 26
if header.flag(Header.FLAG_ADVERT):
if i + 1 > len(buf):
raise CorruptedArchiveError("truncated header")
avsz, = struct.unpack('<B', buf[i:i+1])
i += 1
if i + avsz > len(buf):
raise CorruptedArchiveError("truncated header")
header.advert = buf[i:i+avsz]
i += avsz
if header.flag(Header.FLAG_COMMENT):
if i + 2 > len(buf):
raise CorruptedArchiveError("truncated header")
cmsz, = struct.unpack('<H', buf[i:i+2])
i += 2
if i + cmsz > len(buf):
raise CorruptedArchiveError("truncated header")
header.comment = ACE.decompress_comment(buf[i:i+cmsz])
i += cmsz
header.reserved2 = buf[i:]
if self.__main_header != None:
raise CorruptedArchiveError("multiple main headers")
self.__main_header = header
elif htype in (Header.TYPE_FILE32, Header.TYPE_FILE64):
header = FileHeader(hcrc, hsize, htype, hflags)
if not header.flag(Header.FLAG_ADDSIZE):
raise CorruptedArchiveError("file header with addsize == 0")
if header.flag(Header.FLAG_64BIT):
if htype != Header.TYPE_FILE64:
raise CorruptedArchiveError("64 bit flag in 32 bit header")
if i + 16 > len(buf):
raise CorruptedArchiveError("truncated header")
header.packsize, \
header.origsize, = struct.unpack('<QQ', buf[i:i+16])
i += 16
else:
if htype != Header.TYPE_FILE32:
raise CorruptedArchiveError("32 bit flag in 64 bit header")
if i + 8 > len(buf):
raise CorruptedArchiveError("truncated header")
header.packsize, \
header.origsize, = struct.unpack('<LL', buf[i:i+8])
i += 8
if i + 20 > len(buf):
raise CorruptedArchiveError("truncated header")
header.datetime, \
header.attribs, \
header.crc32, \
header.comptype, \
header.compqual, \
header.params, \
header.reserved1, \
fnsz = struct.unpack('<LLLBBHHH', buf[i:i+20])
i += 20
if i + fnsz > len(buf):
raise CorruptedArchiveError("truncated header")
header.filename = buf[i:i+fnsz]
i += fnsz
if header.flag(Header.FLAG_COMMENT):
if i + 2 > len(buf):
raise CorruptedArchiveError("truncated header")
cmsz, = struct.unpack('<H', buf[i:i+2])
i += 2
if i + cmsz > len(buf):
raise CorruptedArchiveError("truncated header")
header.comment = ACE.decompress_comment(buf[i:i+cmsz])
i += cmsz
if header.flag(Header.FLAG_NTSECURITY):
if i + 2 > len(buf):
raise CorruptedArchiveError("truncated header")
nssz, = struct.unpack('<H', buf[i:i+2])
i += 2
if i + nssz > len(buf):
raise CorruptedArchiveError("truncated header")
header.ntsecurity = buf[i:i+nssz]
i += nssz
header.reserved2 = buf[i:]
header.dataoffset = self.__file.tell()
self.__file_headers.append(header)
self.__file.seek(header.packsize, 1)
elif htype in (Header.TYPE_RECOVERY32,
Header.TYPE_RECOVERY64A,
Header.TYPE_RECOVERY64B):
header = RecoveryHeader(hcrc, hsize, htype, hflags)
if not header.flag(Header.FLAG_ADDSIZE):
raise CorruptedArchiveError("recovery header with addsize == 0")
if header.flag(Header.FLAG_64BIT) and \
htype == Header.TYPE_RECOVERY32:
raise CorruptedArchiveError("64 bit flag in 32 bit header")
if not header.flag(Header.FLAG_64BIT) and \
htype != Header.TYPE_RECOVERY32:
raise CorruptedArchiveError("32 bit flag in 64 bit header")
if header.flag(Header.FLAG_64BIT):
if i + 23 > len(buf):
raise CorruptedArchiveError("truncated header")
header.rcvrsize, \
header.magic, \
header.relstart = struct.unpack('<Q7sQ', buf[i:i+23])
i += 23
else:
if i + 15 > len(buf):
raise CorruptedArchiveError("truncated header")
header.rcvrsize, \
header.magic, \
header.relstart = struct.unpack('<L7sL', buf[i:i+15])
i += 15
if htype == Header.TYPE_RECOVERY64B:
if i + 8 > len(buf):
raise CorruptedArchiveError("truncated header")
header.sectors, \
header.spc, \
header.clustersize = struct.unpack('<HHL', buf[i:i+8])
i += 8
else:
if i + 10 > len(buf):
raise CorruptedArchiveError("truncated header")
header.cluster, \
header.clustersize, \
header.rcvrcrc = struct.unpack('<LLH', buf[i:i+10])
i += 10
header.dataoffset = self.__file.tell()
self.__recovery_headers.append(header)
self.__file.seek(header.rcvrsize, 1)
else:
header = UnknownHeader(hcrc, hsize, htype, hflags)
addsz = 0
if header.flag(Header.FLAG_ADDSIZE):
if header.flag(Header.FLAG_64BIT):
if i + 8 > len(buf):
raise CorruptedArchiveError("truncated header")
addsz, = struct.unpack('<Q', buf[i:i+8])
else:
if i + 4 > len(buf):
raise CorruptedArchiveError("truncated header")
addsz, = struct.unpack('<L', buf[i:i+4])
self.__file.seek(addsz, 1)
self.__all_headers.append(header)
def get_file_headers(self):
return self.__file_headers
def get_recovery_headers(self):
return self.__recovery_headers
def is_locked(self):
return self.__main_header.flag(Header.FLAG_LOCKED)
def is_multivolume(self):
return self.__main_header.flag(Header.FLAG_MULTIVOLUME)
def is_solid(self):
return self.__main_header.flag(Header.FLAG_SOLID)
@property
def advert(self):
return self.__main_header.advert.decode('utf-8', errors='replace')
@property
def comment(self):
return self.__main_header.comment.decode('utf-8', errors='replace')
@property
def cversion(self):
return self.__main_header.cversion
@property
def eversion(self):
return self.__main_header.eversion
@property
def filename(self):
return self.__filename
@property
def datetime(self):
return _dt_fromdos(self.__main_header.datetime)
@property
def platform(self):
return self.__main_header.host_str
@property
def volume(self):
return self.__main_header.volume
class AceArchive:
"""
Represents an ACE archive, possibly consisting of multiple volumes.
:class:`AceArchive` is not directly instantiated; instead, instances are
returned by :meth:`acefile.open`.
When used as a context manager, :class:`AceArchive` ensures that
:meth:`AceArchive.close` is called after the block.
When used as an iterator, :class:`AceArchive` yields instances of
:class:`AceMember` representing all archive members in order of
appearance in the archive.
"""
@classmethod
def _open(cls, file, mode='r', *, search=524288):
"""
Open archive from *file*, which is either a filename or seekable
file-like object, and return an instance of :class:`AceArchive`
representing the opened archive that can function as a context
manager.
Only *mode* 'r' is implemented.
If *search* is 0, the archive must start at position 0 in *file*,
otherwise the first *search* bytes are searched for the magic bytes
``**ACE**`` that mark the ACE main header.
For 1:1 compatibility with the official unace, 1024 sectors are
searched by default, even though none of the SFX stubs that come with
ACE compressors are that large.
Multi-volume archives are represented by a single :class:`AceArchive`
object to the caller, all operations transparently read into subsequent
volumes as required.
To load a multi-volume archive, either open the first volume of the
series by filename, or provide a list or tuple of all file-like
objects or filenames in the correct order in *file*.
"""
return cls(file, mode, search=search)
def __init__(self, file, mode='r', *, search=524288):
"""
See :meth:`AceArchive._open`.
"""
if mode != 'r':
raise NotImplementedError("mode != 'r' not implemented")
if isinstance(file, (tuple, list)):
if len(file) == 0:
raise ValueError("file is empty tuple/list")
else:
file = (file,)
self.__volumes = []
try:
# load volumes
self.__tmp_file = file[0]
self.__volumes.append(AceVolume(file[0], mode, search=search))
self.__tmp_file = None
if self.__volumes[0].is_multivolume():
for f in file[1:]:
self.__tmp_file = f
self.__volumes.append(AceVolume(f, mode, search=0))
self.__tmp_file = None
if len(self.__volumes) == 1 and isinstance(file[0], str):
vol = self.__volumes[0]
while True:
vol = vol.try_load_next_volume(mode)
if not vol:
break
self.__volumes.append(vol)
# check volume linkage
if len(self.__volumes) > 1:
last_volume = None
for vol in self.__volumes:
if not vol.is_multivolume():
raise MultiVolumeArchiveError("single-volume archive")
if last_volume != None and vol.volume != last_volume + 1:
raise MultiVolumeArchiveError("volumes do not match")
last_volume = vol.volume
# build list of members and their file segments across volumes
self.__members = []
headers = []
segments = []
for volume in self.__volumes:
for hdr in volume.get_file_headers():
if len(headers) == 0:
if hdr.flag(Header.FLAG_CONTPREV):
if len(self.__members) > 0:
raise MultiVolumeArchiveError("incomplete file")
# don't raise an error if this is the first file
# in the first volume, to allow opening subsequent
# volumes of multi-volume archives separately
continue
else:
if not hdr.flag(Header.FLAG_CONTPREV):
raise MultiVolumeArchiveError("unexpected new file")
if hdr.filename != headers[-1].filename:
raise MultiVolumeArchiveError("filename mismatch")
headers.append(hdr)
segments.append(volume.file_segment_for(hdr))
if not hdr.flag(Header.FLAG_CONTNEXT):
if len(segments) > 1:
f = MultipleFilesIO(segments)
else:
f = segments[0]
self.__members.append(AceMember(len(self.__members),
headers, f))
headers = []
segments = []
self.__next_read_idx = 0
self.__ace = ACE()
except:
self.close()
raise
def __enter__(self):
"""
Using :class:`AceArchive` as a context manager ensures that
:meth:`AceArchive.close` is called after leaving the block.
"""
return self
def __exit__(self, type, value, traceback):
self.close()
def __iter__(self):
"""
Using :class:`AceArchive` as an iterater will iterate over
:class:`AceMember` objects for all archive members.
"""
return self.__members.__iter__()
def __repr__(self):
return "<%s %r at %#x>" % (self.__class__.__name__,
self.filename,
id(self))
def close(self):
"""
Close the archive and all open files.
No other methods may be called after having called
:meth:`AceArchive.close`, but calling :meth:`AceArchive.close`
multiple times is permitted.
"""
if self.__tmp_file != None:
if not isinstance(self.__tmp_file, str):
self.__tmp_file.close()
self.__tmp_file = None
for volume in self.__volumes:
volume.close()
def _getmember_byname(self, name):
"""
Return an :class:`AceMember` object corresponding to archive member
name *name*.
Raise :class:`KeyError` if *name* is not present in the archive.
If *name* occurs multiple times in the archive, then the last occurence
is returned.
"""
match = None
for am in self.__members:
if am.filename == name:
match = am
if match == None:
raise KeyError("no member '%s' in archive" % name)
return match
def _getmember_byidx(self, idx):
"""
Return an :class:`AceMember` object corresponding to archive member
index *idx*.
Raise :class:`IndexError` if *idx* is not present in the archive.
"""
return self.__members[idx]
def getmember(self, member):
"""
Return an :class:`AceMember` object corresponding to archive
member *member*.
Raise :class:`KeyError` or :class:`IndexError` if *member* is not
found in archive.
*Member* can refer to an :class:`AceMember` object, a member name or
an index into the archive member list.
If *member* is a name and it occurs multiple times in the archive,
then the last member with matching filename is returned.
"""
if isinstance(member, int):
return self._getmember_byidx(member)
elif isinstance(member, AceMember):
return member
elif isinstance(member, str):
return self._getmember_byname(member)
else:
raise TypeError("member argument has unsupported type")
def getmembers(self):
"""
Return a list of :class:`AceMember` objects for the members of the
archive.
The objects are in the same order as they are in the archive.
For simply iterating over the members of an archive, it is more concise
and functionally equivalent to directly iterate over the
:class:`AceArchive` instance instead of over the list returned by
:meth:`AceArchive.getmembers`.
"""
return self.__members
def getnames(self):
"""
Return a list of the (file)names of all the members in the archive
in the order they are in the archive.
"""
return [am.filename for am in self.getmembers()]
def extract(self, member, *, path=None, pwd=None, restore=False):
"""
Extract an archive member to *path* or the current working directory.
*Member* can refer to an :class:`AceMember` object, a member name or
an index into the archive member list.
Password *pwd* is used to decrypt the archive member if it is
encrypted.
Raises :class:`EncryptedArchiveError` if an archive member is
encrypted but no password was provided.
Iff *restore* is True, restore mtime and atime for non-dir members,
file attributes and NT security information as far as supported by
the platform.
.. note::
For **solid** archives, extracting members in a different order
than they appear in the archive works, but is potentially very
slow, because the decompressor needs to restart decompression at
the beginning of the solid archive to restore internal decompressor
state.
For **encrypted solid** archives, out of order access may fail when
archive members use different passwords.
"""
am = self.getmember(member)
if path != None:
fn = os.path.join(path, am.filename)
else:
fn = am.filename
if am.is_dir():
try:
os.mkdir(fn)
except FileExistsError:
pass
else:
basedir = os.path.dirname(fn)
if basedir != '':
os.makedirs(basedir, exist_ok=True)
with builtins.open(fn, 'wb') as f:
for buf in self.readblocks(am, pwd=pwd):
f.write(buf)
if restore:
if SetFileAttributes:
SetFileAttributes(fn, am.attribs)
elif am.attribs & Header.ATTR_READONLY != 0:
mode = stat.S_IMODE(os.lstat(fn).st_mode)
all_w = stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH
os.chmod(fn, mode & ~all_w)
if SetFileSecurity and am.ntsecurity:
SetFileSecurity(fn, 0x7, am.ntsecurity)
if not am.is_dir():
ts = am.datetime.timestamp()
os.utime(fn, (ts, ts))
def extractall(self, *, path=None, members=None, pwd=None, restore=False):
"""
Extract *members* or all members from archive to *path* or the current
working directory.
*Members* can contain :class:`AceMember` objects, member names or
indexes into the archive member list.
Password *pwd* is used to decrypt encrypted archive members.
To extract archives that use multiple different passwords for different
archive members, you must use :meth:`AceArchive.extract` instead.
Raises :class:`EncryptedArchiveError` if an archive member is
encrypted but no password was provided.
Iff *restore* is True, restore mtime and atime for non-dir members,
file attributes and NT security information as far as supported by
the platform.
"""
if members == None or members == []:
members = self.getmembers()
else:
if self.is_solid():
# ensure members subset is in order of appearance
sorted_members = []
for member in self.getmembers():
if member in members or \
member.filename in members or \
member._idx in members:
sorted_members.append(member)
members = sorted_members
for am in members:
self.extract(am, path=path, pwd=pwd, restore=restore)
def read(self, member, *, pwd=None):
"""
Read the decompressed bytes of an archive member.
*Member* can refer to an :class:`AceMember` object, a member name or
an index into the archive member list.
Password *pwd* is used to decrypt the archive member if it is
encrypted.
Raises :class:`EncryptedArchiveError` if the archive member is
encrypted but no password was provided.
.. note::
For **solid** archives, reading members in a different order than
they appear in the archive works, but is potentially very slow,
because the decompressor needs to restart decompression at the
beginning of the solid archive to restore internal decompressor
state.
For **encrypted solid** archives, out of order access may fail when
archive members use different passwords.
.. note::
Using :meth:`AceArchive.read` for large files is inefficient and
may fail for very large files.
Using :meth:`AceArchive.readblocks` to write the data to disk in
blocks ensures that large files can be handled efficiently.
"""
return b''.join(self.readblocks(member, pwd=pwd))
def readblocks(self, member, *, pwd=None):
"""
Read the archive member by yielding blocks of decompressed bytes.
*Member* can refer to an :class:`AceMember` object, a member name or
an index into the archive member list.
Password *pwd* is used to decrypt the archive member if it is
encrypted.
Raises :class:`EncryptedArchiveError` if the archive member is
encrypted but no password was provided.
.. note::
For **solid** archives, reading members in a different order than
they appear in the archive works, but is potentially very slow,
because the decompressor needs to restart decompression at the
beginning of the solid archive to restore internal decompressor
state.
For **encrypted solid** archives, out of order access may fail when
archive members use different passwords.
"""
am = self.getmember(member)
if DEBUG:
eprint(am)
# Need first volume available to read from solid multi-volume archives.
if self.is_solid() and self.is_multivolume() and self.volume > 0:
raise MultiVolumeArchiveError("need first volume")
# For solid archives, ensure the LZ77 state corresponds to the state
# after extracting the previous file by re-starting extraction from
# the beginning or the last extracted file. This is what makes out
# of order access to solid archive members prohibitively slow.
if self.is_solid() and self.__next_read_idx != am._idx:
if self.__next_read_idx < am._idx:
restart_idx = self.__next_read_idx
else:
restart_idx = self.__next_read_idx = 0
for i in range(restart_idx, am._idx):
if not self.test(i):
raise CorruptedArchiveError("failed to restore solid state")
if (not am.is_dir()) and am.size > 0:
f = am._file
f.seek(0, 0)
# For password protected members, wrap the file-like object in
# a decrypting wrapper object.
if am.is_enc():
if not pwd:
raise EncryptedArchiveError("need password")
f = EncryptedFileIO(f, AceBlowfish(pwd))
# Choose the matching decompressor based on the first header.
if am.comptype == Header.COMP_STORED:
decompressor = self.__ace.decompress_stored
elif am.comptype == Header.COMP_LZ77:
decompressor = self.__ace.decompress_lz77
elif am.comptype == Header.COMP_BLOCKED:
decompressor = self.__ace.decompress_blocked
else:
raise UnknownCompressionMethodError(
"method %i unknown" % am.comptype)
# Decompress and calculate CRC over full decompressed data,
# i.e. after decryption and across all segments that may have
# been read from different volumes.
crc = AceCRC32()
try:
for block in decompressor(f, am.size, am.dicsize):
crc += block
yield block
except ValueError:
if am.is_enc():
raise EncryptedArchiveError("wrong password or corrupted")
else:
raise CorruptedArchiveError("ValueError during decomp")
except CorruptedArchiveError:
if am.is_enc():
raise EncryptedArchiveError("wrong password or corrupted")
raise
if crc != am.crc32:
if am.is_enc():
raise EncryptedArchiveError("wrong password or corrupted")
raise CorruptedArchiveError("CRC mismatch")
self.__next_read_idx += 1
def test(self, member, *, pwd=None):
"""
Test an archive member. Returns False if any corruption was
found, True if the header and decompression was okay.
*Member* can refer to an :class:`AceMember` object, a member name or
an index into the archive member list.
Password *pwd* is used to decrypt the archive member if it is
encrypted.
Raises :class:`EncryptedArchiveError` if the archive member is
encrypted but no password was provided.
.. note::
For **solid** archives, testing members in a different order than
they appear in the archive works, but is potentially very slow,
because the decompressor needs to restart decompression at the
beginning of the solid archive to restore internal decompressor
state.
For **encrypted solid** archives, out of order access may fail when
archive members use different passwords.
"""
try:
for buf in self.readblocks(member, pwd=pwd):
pass
return True
except EncryptedArchiveError:
raise
except AceError:
if DEBUG:
raise
return False
def testall(self, *, pwd=None):
"""
Test all the members in the archive. Returns the name of the first
archive member with a failing header or content CRC, or None if all
members were okay.
Password *pwd* is used to decrypt encrypted archive members.
To test archives that use multiple different passwords for different
archive members, use :meth:`AceArchive.test` instead.
Raises :class:`EncryptedArchiveError` if an archive member is
encrypted but no password was provided.
"""
for am in self.getmembers():
if not self.test(am, pwd=pwd):
return am.filename
return None
def dumpheaders(self, file=sys.stdout):
"""
Dump all ACE file format headers in this archive and all its volumes
to *file*.
"""
for volume in self.__volumes:
volume.dumpheaders()
def is_locked(self):
"""
Return True iff archive is locked for further modifications.
Since this implementation does not support writing to archives,
presence or absence of the flag in an archive does not change any
behaviour of :mod:`acefile`.
"""
return self.__volumes[0].is_locked()
def is_multivolume(self):
"""
Return True iff archive is a multi-volume archive as determined
by the archive headers. When opening the last volume of a
multi-volume archive, this returns True even though only a single
volume was loaded.
"""
return self.__volumes[0].is_multivolume()
def is_solid(self):
"""
Return True iff archive is a solid archive, i.e. iff the archive
members are linked to each other by sharing the same LZ77 dictionary.
Members of solid archives should always be read/tested/extracted in
the order they appear in the archive in order to avoid costly
decompression restarts from the beginning of the archive.
"""
return self.__volumes[0].is_solid()
@property
def advert(self):
"""
ACE archive advert string as :class:`str`.
Unregistered versions of ACE compressors communicate that they are
unregistered by including an advert string of
``*UNREGISTERED VERSION*`` in archives they create.
If absent, empty :class:`str`.
"""
return self.__volumes[0].advert
@property
def comment(self):
"""
ACE archive level comment as :class:`str`.
If absent, empty :class:`str`.
"""
return self.__volumes[0].comment
@property
def cversion(self):
"""
ACE creator version. This is equal to the major version of the ACE
compressor used to create the archive, which equals the highest
version of the ACE format supported by the ACE compressor which
produced the archive.
"""
return self.__volumes[0].cversion
@property
def eversion(self):
"""
ACE extractor version. This is the version of the ACE decompressor
required to extract, which equals the version of the ACE format this
archive is compliant with.
"""
return self.__volumes[0].eversion
@property
def filename(self):
"""
ACE archive filename. This is not a property of the archive but rather
just the filename passed to :func:`acefile.open`.
"""
return self.__volumes[0].filename
@property
def datetime(self):
"""
Archive timestamp as :class:`datetime.datetime` object.
"""
return self.__volumes[0].datetime
@property
def platform(self):
"""
String describing the platform on which the ACE archive was created.
This is derived from the *host* field in the archive header.
"""
return self.__volumes[0].platform
@property
def volume(self):
"""
ACE archive volume number of the first volume of this ACE archive.
"""
return self.__volumes[0].volume
@property
def volumes_loaded(self):
"""
Number of loaded volumes in this archives. When opening a subsequent
volume of a multi-volume archive, this may be lower than the
theoretical volume count.
"""
return len(self.__volumes)
def is_acefile(file, *, search=524288):
"""
Return True iff *file* refers to an ACE archive by filename or seekable
file-like object.
If *search* is 0, the archive must start at position 0 in *file*,
otherwise the first *search* bytes are searched for the magic bytes
``**ACE**`` that mark the ACE main header.
For 1:1 compatibility with the official unace, 1024 sectors are
searched by default, even though none of the SFX stubs that come with
ACE compressors are that large.
"""
try:
with open(file, search=search) as f:
pass
return True
except AceError:
return False
#: The compression type constant for no compression.
COMP_STORED = Header.COMP_STORED
#: The compression type constant for ACE 1.0 LZ77 mode.
COMP_LZ77 = Header.COMP_LZ77
#: The compression type constant for ACE 2.0 blocked mode.
COMP_BLOCKED = Header.COMP_BLOCKED
#: The compression quality constant for no compression.
QUAL_NONE = Header.QUAL_NONE
#: The compression quality constant for fastest compression.
QUAL_FASTEST = Header.QUAL_FASTEST
#: The compression quality constant for fast compression.
QUAL_FAST = Header.QUAL_FAST
#: The compression quality constant for normal compression.
QUAL_NORMAL = Header.QUAL_NORMAL
#: The compression quality constant for good compression.
QUAL_GOOD = Header.QUAL_GOOD
#: The compression quality constant for best compression.
QUAL_BEST = Header.QUAL_BEST
open = AceArchive._open
__all__ = ['is_acefile', 'open']
__all__.extend(filter(lambda name: name.startswith('COMP_'),
sorted(list(globals()))))
__all__.extend(filter(lambda name: name.startswith('QUAL_'),
sorted(list(globals()))))
__all__.extend(filter(lambda name: name.endswith('Error'),
sorted(list(globals()))))
def unace():
import argparse
import getpass
import signal
def title(docstr):
return docstr.strip().split('\n', 1)[0]
class Status:
def __init__(self, argv0, action, archive):
self.argv0 = os.path.basename(argv0)
self.action = action + 'ing'
self.archive = os.path.basename(archive)
self.member = ''
def __str__(self):
return "%s: %s %s %s" % (self.argv0, self.action,
self.archive, self.member)
status = None
def siginfo_handler(signum, frame):
eprint(status)
parser = argparse.ArgumentParser(description=title(__doc__))
parser.add_argument('archive', type=str,
help='archive to read from')
parser.add_argument('file', nargs='*', type=str,
help='file(s) in archive to operate on, default all')
parser.add_argument('-V', '--version', action='version',
version='acefile %s' % __version__,
help='show version and exit')
group = parser.add_mutually_exclusive_group()
group.add_argument('--extract', '-x', default='extract',
action='store_const', dest='mode', const='extract',
help='extract files in archive (default)')
group.add_argument('--test', '-t',
action='store_const', dest='mode', const='test',
help='test archive integrity')
group.add_argument('--list', '-l',
action='store_const', dest='mode', const='list',
help='list files in archive')
group.add_argument('--headers',
action='store_const', dest='mode', const='headers',
help='dump archive headers')
group.add_argument('--selftest',
action='store_const', dest='mode', const='selftest',
help=argparse.SUPPRESS)
parser.add_argument('-d', '--basedir', type=str, default='.', metavar='X',
help='base directory for extraction')
parser.add_argument('-p', '--password', type=str, metavar='X',
help='password for decryption')
parser.add_argument('-r', '--restore', action='store_true',
help='restore mtime/atime, attribs and ntsecurity on extraction')
parser.add_argument('-b', '--batch', action='store_true',
help='suppress all interactive input')
parser.add_argument('-v', '--verbose', action='store_true',
help='be more verbose')
parser.add_argument('--debug', action='store_true',
help='show mode transitions and expose internal exceptions')
# not implemented arguments that other unace implementations have:
# --(no-)full-path always full path extraction
# --(no-)show-comments show comments iff verbose
# --(no-)overwrite-files always overwrite files
# --(no-)full-path-matching always full path matching
# --exclude(-list) feature not implemented
args = parser.parse_args()
if args.mode != 'extract' and len(args.file) > 0:
eprint("%s: error: not extracting, but files were specified" %
os.path.basename(sys.argv[0]))
sys.exit(1)
if args.debug:
global DEBUG
DEBUG = True
if hasattr(signal, 'SIGINFO'):
signal.signal(signal.SIGINFO, siginfo_handler)
status = Status(sys.argv[0], args.mode, args.archive)
if args.archive == '-':
if sys.stdin.buffer.seekable() and platform.system() != 'Windows':
archive = sys.stdin.buffer
else:
archive = io.BytesIO(sys.stdin.buffer.read())
else:
archive = args.archive
try:
with open(archive) as f:
if args.verbose:
if acebitstream == None:
eprint(("warning: acebitstream c extension unavailable, "
"using pure-python bit stream"))
eprint("processing archive %s" % f.filename)
eprint("loaded %i volume(s) starting at volume %i" % (
f.volumes_loaded, f.volume))
archinfo = []
if not f.is_locked():
archinfo.append('not ')
archinfo.append('locked, ')
if not f.is_multivolume():
archinfo.append('not ')
archinfo.append('multi-volume, ')
if not f.is_solid():
archinfo.append('not ')
archinfo.append('solid')
eprint("archive is", ''.join(archinfo))
eprint("last modified %s" % (
f.datetime.strftime('%Y-%m-%d %H:%M:%S')))
eprint("created on %s with ACE %s for extraction with %s+" % (
f.platform, f.cversion/10, f.eversion/10))
if f.advert:
eprint("advert [%s]" % f.advert)
if f.is_multivolume() and f.volume > 0:
eprint("warning: this is not the initial volume of this "
"multi-volume archive")
if f.comment:
eprint(asciibox(f.comment, title='archive comment'))
if args.mode == 'extract':
if f.is_multivolume() and f.volume > 0 and f.is_solid():
eprint(("error: need complete set of volumes to extract "
"from solid multivolume archive"))
sys.exit(1)
failed = 0
password = args.password
if args.file:
members = [f.getmember(m) for m in args.file]
else:
members = f.getmembers()
for am in members:
if status:
status.member = am.filename
if am.is_enc() and password == None and not args.batch:
try:
password = getpass.getpass("%s password: " % \
am.filename)
except EOFError:
password = None
while True:
try:
f.extract(am, path=args.basedir,
pwd=password,
restore=args.restore)
if args.verbose:
eprint("%s" % am.filename)
break
except EncryptedArchiveError:
if args.verbose or args.batch or not password:
eprint("%s failed to decrypt" % am.filename)
if args.batch or not password:
failed += 1
break
try:
password = getpass.getpass("%s password: " % \
am.filename)
except EOFError:
password = ''
if password == '':
password = args.password
eprint("%s skipped" % am.filename)
failed += 1
break
except AceError:
eprint("%s failed to extract" % am.filename)
failed += 1
break
if f.is_solid() and failed > 0:
eprint("error extracting from solid archive, aborting")
sys.exit(1)
if args.verbose and am.comment:
eprint(asciibox(am.comment, title='file comment'))
if failed > 0:
sys.exit(1)
elif args.mode == 'test':
if f.is_multivolume() and f.volume > 0 and f.is_solid():
eprint(("error: need complete set of volumes to test "
"solid multivolume archive"))
sys.exit(1)
failed = 0
ok = 0
password = args.password
for am in f:
if status:
status.member = am.filename
if f.is_solid() and failed > 0:
print("failure %s" % am.filename)
failed += 1
continue
if am.is_enc() and password == None and not args.batch:
try:
password = getpass.getpass("%s password: " % \
am.filename)
except EOFError:
password = None
while True:
try:
if f.test(am, pwd=password):
print("success %s" % am.filename)
ok += 1
else:
print("failure %s" % am.filename)
failed += 1
break
except EncryptedArchiveError:
if args.batch or not password:
print("needpwd %s" % am.filename)
failed += 1
break
eprint("last used password failed")
try:
password = getpass.getpass("%s password: " % \
am.filename)
except EOFError:
password = ''
if password == '':
password = args.password
print("needpwd %s" % am.filename)
failed += 1
break
if args.verbose and am.comment:
eprint(asciibox(am.comment, title='file comment'))
eprint("total %i tested, %i ok, %i failed" % (
ok + failed, ok, failed))
if failed > 0:
sys.exit(1)
elif args.mode == 'list':
if args.verbose:
eprint(("CQD FES size packed rel "
"timestamp filename"))
count = count_size = count_packsize = 0
for am in f:
if am.is_dir():
ft = 'd'
else:
ft = 'f'
if am.is_enc():
en = '+'
else:
en = ' '
if am.ntsecurity:
ns = 's'
else:
ns = ' '
if am.size > 0:
ratio = (100 * am.packsize) // am.size
else:
ratio = 100
print("%i%i%s %s%s%s %9i %9i %3i%% %s %s" % (
am.comptype, am.compqual,
hex(am.dicsizebits - 10)[2:],
ft, en, ns,
am.size,
am.packsize,
ratio,
am.datetime.strftime('%Y-%m-%d %H:%M:%S'),
am.filename))
if am.comment:
eprint(asciibox(am.comment, title='file comment'))
count_size += am.size
count_packsize += am.packsize
count += 1
eprint("total %i members, %i bytes, %i bytes compressed" % (
count, count_size, count_packsize))
else:
for fn in f.getnames():
print("%s" % fn)
elif args.mode == 'headers':
f.dumpheaders()
elif args.mode == 'selftest':
eprint('dumpheaders():')
f.dumpheaders()
eprint('-' * 78)
eprint('getnames():')
for fn in f.getnames():
eprint("%s" % fn)
eprint('-' * 78)
eprint('testall():')
rv = f.testall()
if rv != None:
eprint("Test failed: member %s is corrupted" % rv)
sys.exit(1)
eprint('-' * 78)
eprint('test() in order:')
for member in f:
if f.test(member):
eprint("%s: CRC OK" % member.filename)
else:
eprint("%s: CRC FAILED" % member.filename)
sys.exit(1)
eprint('-' * 78)
eprint('test() in reverse order:')
for member in reversed(f.getmembers()):
if f.test(member):
eprint("%s: CRC OK" % member.filename)
else:
eprint("%s: CRC FAILED" % member.filename)
sys.exit(1)
# end of with open
except AceError as e:
if DEBUG:
raise
eprint("%s: %s: %s" % (args.archive, type(e).__name__, e))
sys.exit(1)
sys.exit(0)
def testsuite():
import doctest
return doctest.DocTestSuite(optionflags=doctest.IGNORE_EXCEPTION_DETAIL)
def test():
import doctest
fails, tests = doctest.testmod(optionflags=doctest.IGNORE_EXCEPTION_DETAIL)
sys.exit(min(1, fails))
if __name__ == '__main__':
if '--doctest' in sys.argv:
test()
unace()Global variables
var COMP_BLOCKED-
The compression type constant for ACE 2.0 blocked mode.
var COMP_LZ77-
The compression type constant for ACE 1.0 LZ77 mode.
var COMP_STORED-
The compression type constant for no compression.
var QUAL_BEST-
The compression quality constant for best compression.
var QUAL_FAST-
The compression quality constant for fast compression.
var QUAL_FASTEST-
The compression quality constant for fastest compression.
var QUAL_GOOD-
The compression quality constant for good compression.
var QUAL_NONE-
The compression quality constant for no compression.
var QUAL_NORMAL-
The compression quality constant for normal compression.
Functions
def is_acefile(file, *, search=524288)-
Return True iff file refers to an ACE archive by filename or seekable file-like object. If search is 0, the archive must start at position 0 in file, otherwise the first search bytes are searched for the magic bytes
**ACE**that mark the ACE main header. For 1:1 compatibility with the official unace, 1024 sectors are searched by default, even though none of the SFX stubs that come with ACE compressors are that large.Expand source code Browse git
def is_acefile(file, *, search=524288): """ Return True iff *file* refers to an ACE archive by filename or seekable file-like object. If *search* is 0, the archive must start at position 0 in *file*, otherwise the first *search* bytes are searched for the magic bytes ``**ACE**`` that mark the ACE main header. For 1:1 compatibility with the official unace, 1024 sectors are searched by default, even though none of the SFX stubs that come with ACE compressors are that large. """ try: with open(file, search=search) as f: pass return True except AceError: return False def open(file, mode='r', *, search=524288)-
Open archive from file, which is either a filename or seekable file-like object, and return an instance of :class:
AceArchiverepresenting the opened archive that can function as a context manager. Only mode 'r' is implemented. If search is 0, the archive must start at position 0 in file, otherwise the first search bytes are searched for the magic bytes**ACE**that mark the ACE main header. For 1:1 compatibility with the official unace, 1024 sectors are searched by default, even though none of the SFX stubs that come with ACE compressors are that large.Multi-volume archives are represented by a single :class:
AceArchiveobject to the caller, all operations transparently read into subsequent volumes as required. To load a multi-volume archive, either open the first volume of the series by filename, or provide a list or tuple of all file-like objects or filenames in the correct order in file.Expand source code Browse git
@classmethod def _open(cls, file, mode='r', *, search=524288): """ Open archive from *file*, which is either a filename or seekable file-like object, and return an instance of :class:`AceArchive` representing the opened archive that can function as a context manager. Only *mode* 'r' is implemented. If *search* is 0, the archive must start at position 0 in *file*, otherwise the first *search* bytes are searched for the magic bytes ``**ACE**`` that mark the ACE main header. For 1:1 compatibility with the official unace, 1024 sectors are searched by default, even though none of the SFX stubs that come with ACE compressors are that large. Multi-volume archives are represented by a single :class:`AceArchive` object to the caller, all operations transparently read into subsequent volumes as required. To load a multi-volume archive, either open the first volume of the series by filename, or provide a list or tuple of all file-like objects or filenames in the correct order in *file*. """ return cls(file, mode, search=search)
Classes
class AceError (*args, **kwargs)-
Base class for all :mod:
acefileexceptions.Expand source code Browse git
class AceError(Exception): """ Base class for all :mod:`acefile` exceptions. """ passAncestors
- builtins.Exception
- builtins.BaseException
Subclasses
class CorruptedArchiveError (*args, **kwargs)-
Archive is corrupted. Either a header or data CRC check failed, an invalid value was read from the archive or the archive is truncated.
Expand source code Browse git
class CorruptedArchiveError(AceError): """ Archive is corrupted. Either a header or data CRC check failed, an invalid value was read from the archive or the archive is truncated. """ passAncestors
- AceError
- builtins.Exception
- builtins.BaseException
class EncryptedArchiveError (*args, **kwargs)-
Archive member is encrypted but either no password was provided, or decompression failed with the given password. Also raised when processing an encrypted solid archive member out of order, when any previous archive member uses a different password than the archive member currently being accessed.
Note
Due to the lack of a password verifier in the ACE file format, there is no straightforward way to distinguish a wrong password from a corrupted archive. If the CRC check of an encrypted archive member fails or an :class:
CorruptedArchiveErroris encountered during decompression, it is assumed that the password was wrong and as a consequence, :class:EncryptedArchiveErroris raised.Expand source code Browse git
class EncryptedArchiveError(AceError): """ Archive member is encrypted but either no password was provided, or decompression failed with the given password. Also raised when processing an encrypted solid archive member out of order, when any previous archive member uses a different password than the archive member currently being accessed. .. note:: Due to the lack of a password verifier in the ACE file format, there is no straightforward way to distinguish a wrong password from a corrupted archive. If the CRC check of an encrypted archive member fails or an :class:`CorruptedArchiveError` is encountered during decompression, it is assumed that the password was wrong and as a consequence, :class:`EncryptedArchiveError` is raised. """ passAncestors
- AceError
- builtins.Exception
- builtins.BaseException
class MainHeaderNotFoundError (*args, **kwargs)-
The main ACE header marked by the magic bytes
**ACE**could not be found. Either the search argument was to small or the archive is not an ACE format archive.Expand source code Browse git
class MainHeaderNotFoundError(AceError): """ The main ACE header marked by the magic bytes ``**ACE**`` could not be found. Either the *search* argument was to small or the archive is not an ACE format archive. """ passAncestors
- AceError
- builtins.Exception
- builtins.BaseException
class MultiVolumeArchiveError (*args, **kwargs)-
A multi-volume archive was expected but a normal archive was found, or mismatching volumes were provided, or while reading a member from a multi-volume archive, the member headers indicate that the member continues in the next volume, but no next volume was found or provided.
Expand source code Browse git
class MultiVolumeArchiveError(AceError): """ A multi-volume archive was expected but a normal archive was found, or mismatching volumes were provided, or while reading a member from a multi-volume archive, the member headers indicate that the member continues in the next volume, but no next volume was found or provided. """ passAncestors
- AceError
- builtins.Exception
- builtins.BaseException
class UnknownCompressionMethodError (*args, **kwargs)-
Data was compressed using an unknown compression method and therefore cannot be decompressed using this implementation. This should not happen for ACE 1.0 or ACE 2.0 archives since this implementation implements all existing compression methods.
Expand source code Browse git
class UnknownCompressionMethodError(AceError): """ Data was compressed using an unknown compression method and therefore cannot be decompressed using this implementation. This should not happen for ACE 1.0 or ACE 2.0 archives since this implementation implements all existing compression methods. """ passAncestors
- AceError
- builtins.Exception
- builtins.BaseException