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e614631025
Pillow/PIL/OleFileIO.py
decalage e614631025 version 0.15 2007-11-25
2014-01-30 23:15:17 +00:00

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#!/usr/local/bin/python
# -*- coding: latin-1 -*-
"""
OleFileIO_PL:
Module to read Microsoft OLE2 files (Structured Storage), such as
Microsoft Office documents, Image Composer and FlashPix files,
Outlook messages, ...
version 0.15 2007-11-25 Philippe Lagadec - http://lagasoft.free.fr
Project website: http://lagasoft.free.fr/python/olefileio
Improved version of OleFileIO module from PIL library v1.1.6
See: http://www.pythonware.com/products/pil/index.htm
The Python Imaging Library (PIL) is
Copyright (c) 1997-2005 by Secret Labs AB
Copyright (c) 1995-2005 by Fredrik Lundh
OleFileIO_PL changes are Copyright (c) 2005-2007 by Philippe Lagadec
See source code and LICENSE.txt for information on usage and redistribution.
WARNING: THIS IS (STILL) WORK IN PROGRESS.
"""
__author__ = "Fredrik Lundh (Secret Labs AB), Philippe Lagadec"
__date__ = "2007-11-25"
__version__ = '0.15'
#-----------------------------------------------------------------------------
# CHANGELOG: (OleFileIO_PL changes only)
# 2005-05-11 v0.10 PL: - a few fixes for Python 2.4 compatibility
# (all changes flagged with [PL])
# 2006-02-22 v0.11 PL: - a few fixes for some Office 2003 documents which raise
# exceptions in _OleStream.__init__()
# 2006-06-09 v0.12 PL: - fixes for files above 6.8MB (DIFAT in loadfat)
# - added some constants
# - added header values checks
# - added some docstrings
# - getsect: bugfix in case sectors >512 bytes
# - getsect: added conformity checks
# - DEBUG_MODE constant to activate debug display
# 2007-09-04 v0.13 PL: - improved/translated (lots of) comments
# - updated license
# - converted tabs to 4 spaces
# 2007-11-19 v0.14 PL: - added OleFileIO.raise_defect() to adapt sensitivity
# - improved _unicode() to use Python 2.x unicode support
# - fixed bug in _OleDirectoryEntry
# 2007-11-25 v0.15 PL: - added safety checks to detect malformed documents
# - fixed _OleStream which didn't check stream size
# - added/improved many docstrings and comments
# - moved helper functions _unicode and _clsid out of
# OleFileIO class
# - improved OleFileIO._find() to add Unix path syntax
# - OleFileIO._find() is now case-insensitive
# - added get_type() and get_rootentry_name()
# - rewritten loaddirectory and _OleDirectoryEntry
#-----------------------------------------------------------------------------
# TODO:
# - add underscore to each private method/constant, to avoid their display in
# pydoc/epydoc documentation
# - replace all raised exceptions with raise_defect (at least in OleFileIO)
# - add dictionary of directory entries indexed on filenames to avoid using
# _find() each time ?
# - fix Unicode names handling (find some way to stay compatible with Py1.5.2)
# => if possible avoid converting names to Latin-1
# - fix handling of DIFSECT blocks in FAT (not stop)
# - add stricter checks in decoding
# - add (optional) checks on FAT block chains integrity to detect crossed
# sectors, loops, ...
# - improve docstrings to show more sample uses
# - fix docstrings to follow epydoc format
# - see also original notes and FIXME below
# - remove all obsolete FIXMEs
#-----------------------------------------------------------------------------
#
# THIS IS WORK IN PROGRESS
#
# The Python Imaging Library
# $Id$
#
# stuff to deal with OLE2 Structured Storage files. this module is
# used by PIL to read Image Composer and FlashPix files, but can also
# be used to read other files of this type.
#
# History:
# 1997-01-20 fl Created
# 1997-01-22 fl Fixed 64-bit portability quirk
# 2003-09-09 fl Fixed typo in OleFileIO.loadfat (noted by Daniel Haertle)
# 2004-02-29 fl Changed long hex constants to signed integers
#
# Notes:
# FIXME: sort out sign problem (eliminate long hex constants)
# FIXME: change filename to use "a/b/c" instead of ["a", "b", "c"]
# FIXME: provide a glob mechanism function (using fnmatchcase)
#
# Literature:
#
# "FlashPix Format Specification, Appendix A", Kodak and Microsoft,
# September 1996.
#
# Quotes:
#
# "If this document and functionality of the Software conflict,
# the actual functionality of the Software represents the correct
# functionality" -- Microsoft, in the OLE format specification
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1997.
#
# See the README file for information on usage and redistribution.
#
#--- LICENSE ------------------------------------------------------------------
# OleFileIO_PL is an improved version of the OleFileIO module from the
# Python Imaging Library (PIL).
# OleFileIO_PL changes are Copyright (c) 2005-2007 by Philippe Lagadec
#
# The Python Imaging Library (PIL) is
# Copyright (c) 1997-2005 by Secret Labs AB
# Copyright (c) 1995-2005 by Fredrik Lundh
#
# By obtaining, using, and/or copying this software and/or its associated
# documentation, you agree that you have read, understood, and will comply with
# the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and its
# associated documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appears in all copies, and that both
# that copyright notice and this permission notice appear in supporting
# documentation, and that the name of Secret Labs AB or the author(s) not be used
# in advertising or publicity pertaining to distribution of the software
# without specific, written prior permission.
#
# SECRET LABS AB AND THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
# SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
# IN NO EVENT SHALL SECRET LABS AB OR THE AUTHORS BE LIABLE FOR ANY SPECIAL,
# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.
#------------------------------------------------------------------------------
import string, StringIO, struct, array, os.path
#[PL] DEBUG display mode:
DEBUG_MODE = False
if DEBUG_MODE:
def debug(msg):
print msg
else:
def debug(msg):
pass
MAGIC = '\320\317\021\340\241\261\032\341'
#[PL]: added constants for Sector IDs (from AAF specifications)
MAXREGSECT = 0xFFFFFFFAL; # maximum SECT
DIFSECT = 0xFFFFFFFCL; # (-4) denotes a DIFAT sector in a FAT
FATSECT = 0xFFFFFFFDL; # (-3) denotes a FAT sector in a FAT
ENDOFCHAIN = 0xFFFFFFFEL; # (-2) end of a virtual stream chain
FREESECT = 0xFFFFFFFFL; # (-1) unallocated sector
#[PL]: added constants for Directory Entry IDs (from AAF specifications)
MAXREGSID = 0xFFFFFFFAL; # maximum directory entry ID
NOSTREAM = 0xFFFFFFFFL; # (-1) unallocated directory entry
#[PL] object types in storage (from AAF specifications)
STGTY_EMPTY = 0 # empty directory entry (according to OpenOffice.org doc)
STGTY_STORAGE = 1 # element is a storage object
STGTY_STREAM = 2 # element is a stream object
STGTY_LOCKBYTES = 3 # element is an ILockBytes object
STGTY_PROPERTY = 4 # element is an IPropertyStorage object
STGTY_ROOT = 5 # element is a root storage
#
# --------------------------------------------------------------------
# property types
VT_EMPTY=0; VT_NULL=1; VT_I2=2; VT_I4=3; VT_R4=4; VT_R8=5; VT_CY=6;
VT_DATE=7; VT_BSTR=8; VT_DISPATCH=9; VT_ERROR=10; VT_BOOL=11;
VT_VARIANT=12; VT_UNKNOWN=13; VT_DECIMAL=14; VT_I1=16; VT_UI1=17;
VT_UI2=18; VT_UI4=19; VT_I8=20; VT_UI8=21; VT_INT=22; VT_UINT=23;
VT_VOID=24; VT_HRESULT=25; VT_PTR=26; VT_SAFEARRAY=27; VT_CARRAY=28;
VT_USERDEFINED=29; VT_LPSTR=30; VT_LPWSTR=31; VT_FILETIME=64;
VT_BLOB=65; VT_STREAM=66; VT_STORAGE=67; VT_STREAMED_OBJECT=68;
VT_STORED_OBJECT=69; VT_BLOB_OBJECT=70; VT_CF=71; VT_CLSID=72;
VT_VECTOR=0x1000;
# map property id to name (for debugging purposes)
VT = {}
for k, v in vars().items():
if k[:3] == "VT_":
VT[v] = k
#
# --------------------------------------------------------------------
# Some common document types (root.clsid fields)
WORD_CLSID = "00020900-0000-0000-C000-000000000046"
#[PL]: Defect levels to classify parsing errors - see OleFileIO.raise_defect()
DEFECT_UNSURE = 10 # a case which looks weird, but not sure it's a defect
DEFECT_POTENTIAL = 20 # a potential defect
DEFECT_INCORRECT = 30 # an error according to specifications, but parsing
# can go on
DEFECT_FATAL = 40 # an error which cannot be ignored, parsing is
# impossible
#--- FUNCTIONS ----------------------------------------------------------------
#TODO: replace i16 and i32 with more readable struct.unpack equivalent
def i16(c, o = 0):
"""
Converts a 2-bytes (16 bits) string to an integer.
c: string containing bytes to convert
o: offset of bytes to convert in string
"""
return ord(c[o])+(ord(c[o+1])<<8)
def i32(c, o = 0):
"""
Converts a 4-bytes (32 bits) string to an integer.
c: string containing bytes to convert
o: offset of bytes to convert in string
"""
return int(ord(c[o])+(ord(c[o+1])<<8)+(ord(c[o+2])<<16)+(ord(c[o+3])<<24))
# [PL]: added int() because "<<" gives long int since Python 2.4
def _clsid(clsid):
"""
Converts a CLSID to a human-readable string.
clsid: string of length 16.
"""
assert len(clsid) == 16
if clsid == "\0" * len(clsid):
return ""
return (("%08X-%04X-%04X-%02X%02X-" + "%02X" * 6) %
((i32(clsid, 0), i16(clsid, 4), i16(clsid, 6)) +
tuple(map(ord, clsid[8:16]))))
def _unicode(s):
"""
Map unicode string to Latin 1.
"""
#[PL]: use Python Unicode features when available (Python>=2.0):
#TODO: test this with old Python versions <2.0
#TODO: test if it OleFileIO works with Unicode strings, instead of
# converting to Latin-1.
try:
# First the string is converted to plain Unicode:
# (assuming it is encoded as UTF-16 little-endian)
u = unicode(s, 'UTF-16LE')
except NameError:
# If the unicode function does not exist, we assume this is an old
# Python version without Unicode support.
# Null bytes are simply removed (this only works with usual Latin-1
# strings which do not contain unicode characters>256):
return filter(ord, s)
except ValueError:
# there was an error during UTF-16 to Unicode decoding:
self.raise_defect(DEFECT_INCORRECT, 'incorrect Unicode name')
# if no exception raised, fallback to foolproof version:
return filter(ord, s)
try:
# Second the unicode string is converted to Latin-1
return u.encode('latin_1')
except UnicodeError: # possible issue: this exception didn't exist before
# there was an error during Unicode to Latin-1 encoding:
self.raise_defect(DEFECT_INCORRECT, 'incorrect Unicode name')
# if no exception raised, fallback to foolproof version:
return filter(ord, s)
#=== CLASSES ==================================================================
#--- _OleStream ---------------------------------------------------------------
class _OleStream(StringIO.StringIO):
"""
OLE2 Stream
Returns a read-only file object which can be used to read
the contents of a OLE stream (instance of the StringIO class).
To open a stream, use the openstream method in the OleFile class.
This function can be used with either ordinary streams,
or ministreams, depending on the offset, sectorsize, and
fat table arguments.
Attributes:
- size: actual size of data stream, after it was opened.
"""
# FIXME: should store the list of sects obtained by following
# the fat chain, and load new sectors on demand instead of
# loading it all in one go.
def __init__(self, fp, sect, size, offset, sectorsize, fat):
"""
Constructor for _OleStream class.
fp : file object, the OLE container
sect : sector index of first sector in the stream
size : total size of the stream
offset : offset in bytes for the first FAT or MiniFAT sector
sectorsize: size of one sector
fat : array/list of sector indexes (FAT or MiniFAT)
return : a StringIO instance containing the OLE stream
"""
debug('_OleStream.__init__:')
debug(' size=%d, offset=%d, sectorsize=%d, len(fat)=%d'
%(size,offset,sectorsize,len(fat)))
#[PL] To detect malformed documents with FAT loops, we compute the
# expected number of sectors in the stream:
if size==0x7FFFFFFF:
# this is the case when called from OleFileIO._open(), and stream
# size is not known in advance (for example when reading the
# Directory stream). Then we can only guess maximum size:
size = len(fat)*sectorsize
nb_sectors = (size + (sectorsize-1)) / sectorsize
# This number should (at least) be less than the total number of
# sectors in the given FAT:
if nb_sectors > len(fat):
raise IOError, 'malformed OLE document, stream too large'
# optimization(?): data is first a list of strings, and join() is called
# at the end to concatenate all in one string.
# (this may not be really useful with recent Python versions)
data = []
#[PL] first sector index should be within FAT or ENDOFCHAIN:
if sect != ENDOFCHAIN and (sect<0 or sect>=len(fat)):
raise IOError, 'incorrect OLE FAT, sector index out of range'
#[PL] A fixed-length for loop is used instead of an undefined while
# loop to avoid DoS attacks:
for i in xrange(nb_sectors):
#TODO: check if this works with 4K sectors:
fp.seek(offset + sectorsize * sect)
sector_data = fp.read(sectorsize)
# [PL] check if there was enough data:
if len(sector_data) != sectorsize:
raise IOError, 'incomplete OLE sector'
data.append(sector_data)
# jump to next sector in the FAT:
try:
#[PL] sector index should not be negative, but Python allows it
if sect<0: raise IndexError
sect = fat[sect]
if sect == ENDOFCHAIN:
# this may happen when size was not known:
break
except IndexError:
# [PL] if pointer is out of the FAT an exception is raised
raise IOError, 'incorrect OLE FAT, sector index out of range'
#[PL] Last sector should be a "end of chain" marker:
if sect != ENDOFCHAIN:
raise IOError, 'incorrect last sector index in OLE stream'
data = string.join(data, "")
# Data is truncated to the actual stream size:
if len(data) > size:
data = data[:size]
# actual stream size is stored for future use:
self.size = size
else:
# actual stream size was not known, now we know the size of read
# data:
self.size = len(data)
# when all data is read in memory, StringIO constructor is called
StringIO.StringIO.__init__(self, data)
# Then the _OleStream object can be used as a read-only file object.
#--- _OleDirectoryEntry -------------------------------------------------------
# FIXME: should add a counter in here to avoid looping forever
# if the tree is broken.
class _OleDirectoryEntry:
"""
OLE2 Directory Entry
"""
#[PL] parsing code moved from OleFileIO.loaddirectory
# struct to parse directory entries:
# <: little-endian byte order
# 64s: string containing entry name in unicode (max 31 chars) + null char
# H: uint16, number of bytes used in name buffer, including null = (len+1)*2
# B: uint8, dir entry type (between 0 and 5)
# B: uint8, color: 0=black, 1=red
# I: uint32, index of left child node in the red-black tree, NOSTREAM if none
# I: uint32, index of right child node in the red-black tree, NOSTREAM if none
# I: uint32, index of child root node if it is a storage, else NOSTREAM
# 16s: CLSID, unique identifier (only used if it is a storage)
# I: uint32, user flags
# 8s: uint64, creation timestamp or zero
# 8s: uint64, modification timestamp or zero
# I: uint32, SID of first sector if stream or ministream, SID of 1st sector
# of stream containing ministreams if root entry, 0 otherwise
# I: uint32, total stream size in bytes if stream (low 32 bits), 0 otherwise
# I: uint32, total stream size in bytes if stream (high 32 bits), 0 otherwise
STRUCT_DIRENTRY = '<64sHBBIII16sI8s8sIII'
# size of a directory entry: 128 bytes
DIRENTRY_SIZE = 128
assert struct.calcsize(STRUCT_DIRENTRY) == DIRENTRY_SIZE
def __init__(self, entry, sid, olefile):
"""
Constructor for an _OleDirectoryEntry object.
Parses a 128-bytes entry from the OLE Directory stream.
entry: string (must be 128 bytes long)
olefile: OleFileIO containing this directory entry
"""
self.sid = sid
# ref to olefile is stored for future use
self.olefile = olefile
# kids is the list of children entries, if this entry is a storage:
# (list of _OleDirectoryEntry objects)
self.kids = []
# flag used to detect if the entry is referenced more than once in
# directory:
self.used = False
# decode DirEntry
(
name,
namelength,
self.entry_type,
self.color,
self.sid_left,
self.sid_right,
self.sid_child,
clsid,
self.dwUserFlags,
self.createTime,
self.modifyTime,
self.isectStart,
sizeLow,
sizeHigh
) = struct.unpack(_OleDirectoryEntry.STRUCT_DIRENTRY, entry)
if self.entry_type not in [STGTY_ROOT, STGTY_STORAGE, STGTY_STREAM, STGTY_EMPTY]:
olefile.raise_defect(DEFECT_INCORRECT, 'unhandled OLE storage type')
#debug (struct.unpack(fmt_entry, entry[:len_entry]))
# name should be at most 31 unicode characters + null character,
# so 64 bytes in total (31*2 + 2):
if namelength>64:
olefile.raise_defect(DEFECT_INCORRECT, 'incorrect DirEntry name length')
# if exception not raised, namelength is set to the maximum value:
namelength = 64
# only characters without ending null char are kept:
name = name[:(namelength-2)]
# name is converted from unicode to Latin-1:
self.name = _unicode(name)
# sizeHigh is only used for 4K sectors, it should be zero for 512 bytes
# sectors:
if olefile.sectorsize == 512 and sizeHigh != 0:
olefile.raise_defect(DEFECT_INCORRECT, 'incorrect OLE stream size')
self.size = sizeLow + (long(sizeHigh)<<32)
self.clsid = _clsid(clsid)
debug('DirEntry SID=%d: %s' % (self.sid, self.name))
debug(' - type: %d' % self.entry_type)
debug(' - sect: %d' % self.isectStart)
debug(' - size: %d (sizeLow=%d, sizeHigh=%d)' % (self.size, sizeLow, sizeHigh))
debug(' - SID left: %d, right: %d, child: %d' % (self.sid_left,
self.sid_right, self.sid_child))
def build_storage_tree(self):
"""
Read and build the red-black tree attached to this _OleDirectoryEntry
object, if it is a storage.
Note that this method builds a tree of all subentries, so it should
only be called for the root object once.
"""
debug('build_storage_tree: SID=%d - %s - sid_child=%d'
% (self.sid, self.name, self.sid_child))
if self.sid_child != NOSTREAM:
# if child SID is not NOSTREAM, then this entry is a storage.
# Let's walk through the tree of children to fill the kids list:
self.append_kids(self.sid_child)
# Note from OpenOffice documentation: the safest way is to
# recreate the tree because some implementations may store broken
# red-black trees...
# in the OLE file, entries are sorted on (length, name).
# for convenience, we sort them on name instead:
# (see __cmp__ method in this class)
self.kids.sort()
def append_kids(self, child_sid):
"""
Walk through red-black tree of children of this directory entry to add
all of them to the kids list. (recursive method)
child_sid : index of child directory entry to use, or None when called
first time for the root. (only used during recursion)
"""
#[PL] this method was added to use simple recursion instead of a complex
# algorithm.
# if this is not a storage or a leaf of the tree, nothing to do:
if child_sid == NOSTREAM:
return
# check if child SID is in the proper range:
if child_sid<0 or child_sid>=len(self.olefile.direntries):
self.olefile.raise_defect(DEFECT_FATAL, 'OLE DirEntry index out of range')
# get child direntry:
child = self.olefile.direntries[child_sid]
debug('append_kids: child_sid=%d - %s - sid_left=%d, sid_right=%d, sid_child=%d'
% (child.sid, child.name, child.sid_left, child.sid_right, child.sid_child))
# the directory entries are organized as a red-black tree.
# (cf. Wikipedia for details)
# First walk through left side of the tree:
self.append_kids(child.sid_left)
# Then the child_sid _OleDirectoryEntry object is appended to the
# kids list:
self.kids.append(child)
# Check if kid was not already referenced in a storage:
if child.used:
self.olefile.raise_defect(DEFECT_INCORRECT,
'OLE Entry referenced more than once')
child.used = True
# Finally walk through right side of the tree:
self.append_kids(child.sid_right)
# Afterwards build kid's own tree if it's also a storage:
child.build_storage_tree()
def __cmp__(self, other):
"Compare entries by name"
return cmp(self.name, other.name)
def dump(self, tab = 0):
"Dump this entry, and all its subentries (for debug purposes only)"
TYPES = ["(invalid)", "(storage)", "(stream)", "(lockbytes)",
"(property)", "(root)"]
print " "*tab + repr(self.name), TYPES[self.entry_type],
if self.entry_type in (STGTY_STREAM, STGTY_ROOT):
print self.size, "bytes",
print
if self.entry_type in (STGTY_STORAGE, STGTY_ROOT) and self.clsid:
print " "*tab + "{%s}" % self.clsid
for kid in self.kids:
kid.dump(tab + 2)
#--- OleFileIO ----------------------------------------------------------------
class OleFileIO:
"""
OLE container object
This class encapsulates the interface to an OLE 2 structured
storage file. Use the {@link listdir} and {@link openstream} methods to
access the contents of this file.
Object names are given as a list of strings, one for each subentry
level. The root entry should be omitted. For example, the following
code extracts all image streams from a Microsoft Image Composer file:
ole = OleFileIO("fan.mic")
for entry in ole.listdir():
if entry[1:2] == "Image":
fin = ole.openstream(entry)
fout = open(entry[0:1], "wb")
while 1:
s = fin.read(8192)
if not s:
break
fout.write(s)
You can use the viewer application provided with the Python Imaging
Library to view the resulting files (which happens to be standard
TIFF files).
"""
def __init__(self, filename = None, raise_defects=DEFECT_FATAL):
"""
Constructor for OleFileIO class.
filename: file to open.
raise_defects: minimal level for defects to be raised as exceptions.
(use DEFECT_FATAL for a typical application, DEFECT_INCORRECT for a
security-oriented application, see source code for details)
"""
self.raise_defects_level = raise_defects
if filename:
self.open(filename)
def raise_defect(self, defect_level, message):
"""
This method should be called for any defect found during file parsing.
It may raise an IOError exception according to the minimal level chosen
for the OleFileIO object.
defect_level: defect level, possible values are:
DEFECT_UNSURE : a case which looks weird, but not sure it's a defect
DEFECT_POTENTIAL : a potential defect
DEFECT_INCORRECT : an error according to specifications, but parsing can go on
DEFECT_FATAL : an error which cannot be ignored, parsing is impossible
message: string describing the defect, used with raised exception.
"""
# added by [PL]
if defect_level >= self.raise_defects_level:
raise IOError, message
def open(self, filename):
"""
Open an OLE2 file.
Reads the header, FAT and directory.
"""
if type(filename) == type(""):
self.fp = open(filename, "rb")
else:
self.fp = filename
header = self.fp.read(512)
if len(header) != 512 or header[:8] != MAGIC:
self.raise_defect(DEFECT_FATAL, "not an OLE2 structured storage file")
# [PL] header structure according to AAF specifications:
##Header
##struct StructuredStorageHeader { // [offset from start (bytes), length (bytes)]
##BYTE _abSig[8]; // [00H,08] {0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1,
## // 0x1a, 0xe1} for current version
##CLSID _clsid; // [08H,16] reserved must be zero (WriteClassStg/
## // GetClassFile uses root directory class id)
##USHORT _uMinorVersion; // [18H,02] minor version of the format: 33 is
## // written by reference implementation
##USHORT _uDllVersion; // [1AH,02] major version of the dll/format: 3 for
## // 512-byte sectors, 4 for 4 KB sectors
##USHORT _uByteOrder; // [1CH,02] 0xFFFE: indicates Intel byte-ordering
##USHORT _uSectorShift; // [1EH,02] size of sectors in power-of-two;
## // typically 9 indicating 512-byte sectors
##USHORT _uMiniSectorShift; // [20H,02] size of mini-sectors in power-of-two;
## // typically 6 indicating 64-byte mini-sectors
##USHORT _usReserved; // [22H,02] reserved, must be zero
##ULONG _ulReserved1; // [24H,04] reserved, must be zero
##FSINDEX _csectDir; // [28H,04] must be zero for 512-byte sectors,
## // number of SECTs in directory chain for 4 KB
## // sectors
##FSINDEX _csectFat; // [2CH,04] number of SECTs in the FAT chain
##SECT _sectDirStart; // [30H,04] first SECT in the directory chain
##DFSIGNATURE _signature; // [34H,04] signature used for transactions; must
## // be zero. The reference implementation
## // does not support transactions
##ULONG _ulMiniSectorCutoff; // [38H,04] maximum size for a mini stream;
## // typically 4096 bytes
##SECT _sectMiniFatStart; // [3CH,04] first SECT in the MiniFAT chain
##FSINDEX _csectMiniFat; // [40H,04] number of SECTs in the MiniFAT chain
##SECT _sectDifStart; // [44H,04] first SECT in the DIFAT chain
##FSINDEX _csectDif; // [48H,04] number of SECTs in the DIFAT chain
##SECT _sectFat[109]; // [4CH,436] the SECTs of first 109 FAT sectors
##};
# [PL] header decoding:
# '<' indicates little-endian byte ordering for Intel (cf. struct module help)
fmt_header = '<8s16sHHHHHHLLLLLLLLLL'
header_size = struct.calcsize(fmt_header)
debug( "fmt_header size = %d, +FAT = %d" % (header_size, header_size + 109*4) )
header1 = header[:header_size]
(Sig, clsid, MinorVersion, DllVersion, ByteOrder, SectorShift,
MiniSectorShift, Reserved, Reserved1, csectDir, self.csectFat, sectDirStart,
signature, MiniSectorCutoff, MiniFatStart, csectMiniFat, self.sectDifStart,
self.csectDif) = struct.unpack(fmt_header, header1)
debug( struct.unpack(fmt_header, header1))
if Sig != '\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1':
# OLE signature should always be present
self.raise_defect(DEFECT_FATAL, "incorrect OLE signature")
if clsid != '\x00'*16:
# according to AAF specs, CLSID should always be zero
self.raise_defect(DEFECT_INCORRECT, "incorrect CLSID in OLE header")
debug( "MinorVersion = %d" % MinorVersion )
debug( "DllVersion = %d" % DllVersion )
if DllVersion not in [3, 4]:
# version 3: usual format, 512 bytes per sector
# version 4: large format, 4K per sector
self.raise_defect(DEFECT_INCORRECT, "incorrect DllVersion in OLE header")
debug( "ByteOrder = %X" % ByteOrder )
if ByteOrder != 0xFFFE:
# For now only common little-endian documents are handled correctly
self.raise_defect(DEFECT_FATAL, "incorrect ByteOrder in OLE header")
# TODO: add big-endian support for documents created on Mac ?
SectorSize = 2**SectorShift
debug( "SectorSize = %d" % SectorSize )
if SectorSize not in [512, 4096]:
self.raise_defect(DEFECT_INCORRECT, "incorrect SectorSize in OLE header")
if (DllVersion==3 and SectorSize!=512) or (DllVersion==4 and SectorSize!=4096):
self.raise_defect(DEFECT_INCORRECT, "SectorSize does not match DllVersion in OLE header")
MiniSectorSize = 2**MiniSectorShift
debug( "MiniSectorSize = %d" % MiniSectorSize )
if MiniSectorSize not in [64]:
self.raise_defect(DEFECT_INCORRECT, "incorrect MiniSectorSize in OLE header")
if Reserved != 0 or Reserved1 != 0:
self.raise_defect(DEFECT_INCORRECT, "incorrect OLE header")
debug( "csectDir = %d" % csectDir )
if SectorSize==512 and csectDir!=0:
self.raise_defect(DEFECT_INCORRECT, "incorrect csectDir in OLE header")
debug( "csectFat = %d" % self.csectFat )
debug( "sectDirStart = %X" % sectDirStart )
debug( "signature = %d" % signature )
if signature != 0:
self.raise_defect(DEFECT_INCORRECT, "incorrect OLE header")
debug( "MiniSectorCutoff = %d" % MiniSectorCutoff )
debug( "MiniFatStart = %X" % MiniFatStart )
debug( "csectMiniFat = %d" % csectMiniFat )
debug( "sectDifStart = %X" % self.sectDifStart )
debug( "csectDif = %d" % self.csectDif )
# calculate the number of sectors in the file
# (-1 because header doesn't count)
self.nb_sect = (os.path.getsize(filename) / SectorSize) - 1
debug( "Number of sectors in the file: %d" % self.nb_sect )
# file clsid (probably never used, so we don't store it)
clsid = _clsid(header[8:24])
self.sectorsize = 1 << i16(header, 30)
self.minisectorsize = 1 << i16(header, 32)
self.minisectorcutoff = i32(header, 56)
# Load file allocation tables
self.loadfat(header)
# Load direcory. This sets both the direntries list (ordered by sid)
# and the root (ordered by hierarchy) members.
self.loaddirectory(i32(header, 48))
self.ministream = None
self.minifatsect = i32(header, 60)
def dumpfat(self, fat, firstindex=0):
"Displays a part of FAT in human-readable form for debugging purpose"
# [PL] added only for debug
if not DEBUG_MODE:
return
# dictionary to convert special FAT values in human-readable strings
VPL=8 # valeurs par ligne (8+1 * 8+1 = 81)
fatnames = {
FREESECT: "..free..",
ENDOFCHAIN: "[ END. ]",
FATSECT: "FATSECT ",
DIFSECT: "DIFSECT "
}
nbsect = len(fat)
nlines = (nbsect+VPL-1)/VPL
print "index",
for i in range(VPL):
print ("%8X" % i),
print ""
for l in range(nlines):
index = l*VPL
print ("%8X:" % (firstindex+index)),
for i in range(index, index+VPL):
if i>=nbsect:
break
sect = fat[i]
if sect in fatnames:
nom = fatnames[sect]
else:
if sect == i+1:
nom = " --->"
else:
nom = "%8X" % sect
print nom,
print ""
def dumpsect(self, sector, firstindex=0):
"Displays a sector in a human-readable form, for debugging purpose."
if not DEBUG_MODE:
return
VPL=8 # number of values per line (8+1 * 8+1 = 81)
tab = array.array('L', sector)
nbsect = len(tab)
nlines = (nbsect+VPL-1)/VPL
print "index",
for i in range(VPL):
print ("%8X" % i),
print ""
for l in range(nlines):
index = l*VPL
print ("%8X:" % (firstindex+index)),
for i in range(index, index+VPL):
if i>=nbsect:
break
sect = tab[i]
nom = "%8X" % sect
print nom,
print ""
def loadfat_sect(self, sect):
"""
Adds the indexes of the given sector to the FAT
sect: string containing the first FAT sector, or array of long integers
return: index of last FAT sector.
"""
# a FAT sector is an array of ulong integers.
if isinstance(sect, array.array):
# if sect is already an array it is directly used
fat1 = sect
else:
# if it's a raw sector, it is parsed in an array
fat1 = array.array('L', sect)
self.dumpsect(sect)
# The FAT is a sector chain starting at the first index of itself.
for isect in fat1:
#print "isect = %X" % isect
if isect == ENDOFCHAIN or isect == FREESECT:
# the end of the sector chain has been reached
break
# read the FAT sector
s = self.getsect(isect)
# parse it as an array of 32 bits integers, and add it to the
# global FAT array
self.fat = self.fat + array.array('L', s)
return isect
def loadfat(self, header):
"""
Load the FAT table.
"""
# The header contains a sector numbers
# for the first 109 FAT sectors. Additional sectors are
# described by DIF blocks
sect = header[76:512]
debug( "len(sect)=%d, so %d integers" % (len(sect), len(sect)/4) )
#fat = []
# [PL] FAT is an array of 32 bits unsigned ints, it's more effective
# to use an array than a list in Python.
# It's initialized as empty first:
self.fat = array.array('L')
self.loadfat_sect(sect)
#self.dumpfat(self.fat)
## for i in range(0, len(sect), 4):
## ix = i32(sect, i)
## #[PL] if ix == -2 or ix == -1: # ix == 0xFFFFFFFEL or ix == 0xFFFFFFFFL:
## if ix == 0xFFFFFFFEL or ix == 0xFFFFFFFFL:
## break
## s = self.getsect(ix)
## #fat = fat + map(lambda i, s=s: i32(s, i), range(0, len(s), 4))
## fat = fat + array.array('L', s)
if self.csectDif != 0:
# [PL] There's a DIFAT because file is larger than 6.8MB
# some checks just in case:
if self.csectFat <= 109:
# there must be at least 109 blocks in header and the rest in
# DIFAT, so number of sectors must be >109.
self.raise_defect(DEFECT_INCORRECT, 'incorrect DIFAT, not enough sectors')
if self.sectDifStart >= self.nb_sect:
# initial DIFAT block index must be valid
self.raise_defect(DEFECT_FATAL, 'incorrect DIFAT, first index out of range')
debug( "DIFAT analysis..." )
# We compute the necessary number of DIFAT sectors :
# (each DIFAT sector = 127 pointers + 1 towards next DIFAT sector)
nb_difat = (self.csectFat-109 + 126)/127
debug( "nb_difat = %d" % nb_difat )
if self.csectDif != nb_difat:
raise IOError, 'incorrect DIFAT'
isect_difat = self.sectDifStart
for i in xrange(nb_difat):
debug( "DIFAT block %d, sector %X" % (i, isect_difat) )
#TODO: check if corresponding FAT SID = DIFSECT
sector_difat = self.getsect(isect_difat)
difat = array.array('L', sector_difat)
self.dumpsect(sector_difat)
self.loadfat_sect(difat[:127])
# last DIFAT pointer is next DIFAT sector:
isect_difat = difat[127]
debug( "next DIFAT sector: %X" % isect_difat )
# checks:
if isect_difat not in [ENDOFCHAIN, FREESECT]:
# last DIFAT pointer value must be ENDOFCHAIN or FREESECT
raise IOError, 'incorrect end of DIFAT'
## if len(self.fat) != self.csectFat:
## # FAT should contain csectFat blocks
## print "FAT length: %d instead of %d" % (len(self.fat), self.csectFat)
## raise IOError, 'incorrect DIFAT'
self.dumpfat(self.fat)
def loadminifat(self):
"""
Load the MiniFAT table.
"""
# This is stored in a standard sub-stream, pointed to by a header
# field.
s = self._open(self.minifatsect).read()
#[PL] Old code replaced by an array:
#self.minifat = map(lambda i, s=s: i32(s, i), range(0, len(s), 4))
self.minifat = array.array('L', s)
def getsect(self, sect):
"""
Read given sector from file on disk.
sect: sector index
returns a string containing the sector data.
"""
# [PL] this original code was wrong when sectors are 4KB instead of
# 512 bytes:
#self.fp.seek(512 + self.sectorsize * sect)
#[PL]: added safety checks:
#print "getsect(%X)" % sect
try:
self.fp.seek(self.sectorsize * (sect+1))
except:
self.raise_defect(DEFECT_FATAL, 'wrong index for OLE sector')
sector = self.fp.read(self.sectorsize)
if len(sector) != self.sectorsize:
self.raise_defect(DEFECT_FATAL, 'incomplete OLE sector')
return sector
def loaddirectory(self, sect):
"""
Load the directory.
sect: sector index of directory stream.
"""
# The directory is stored in a standard
# substream, independent of its size.
# open directory stream as a read-only file:
# (stream size is not known in advance)
fp = self._open(sect)
#[PL] to detect malformed documents and avoid DoS attacks, the maximum
# number of directory entries can be calculated:
max_entries = fp.size / 128
debug('loaddirectory: size=%d, max_entries=%d' % (fp.size, max_entries))
# Create list of directory entries
self.direntries = []
for sid in xrange(max_entries):
entry = fp.read(128)
if not entry:
break
self.direntries.append(_OleDirectoryEntry(entry, sid, self))
# Root entry is the first entry:
self.root = self.direntries[0]
# read and build all storage trees, starting from the root:
self.root.build_storage_tree()
def dumpdirectory(self):
"""
Dump directory (for debugging only)
"""
self.root.dump()
def _open(self, start, size = 0x7FFFFFFF):
"""
Open a stream, either in FAT or MiniFAT according to its size.
(openstream helper)
start: index of first sector
size: size of stream (or nothing if size is unknown)
"""
# stream size is compared to the MiniSectorCutoff threshold:
if size < self.minisectorcutoff:
# ministream object
if not self.ministream:
# load MiniFAT if it wasn't already done:
self.loadminifat()
# The first sector index of the miniFAT stream is stored in the
# root directory entry:
self.ministream = self._open(self.root.isectStart)
return _OleStream(self.ministream, start, size, 0,
self.minisectorsize, self.minifat)
else:
# standard stream
return _OleStream(self.fp, start, size, 512,
self.sectorsize, self.fat)
def _list(self, files, prefix, node):
"""
(listdir helper)
files: list of files to fill in
prefix: current location in storage tree (list of names)
node: current node (_OleDirectoryEntry object)
"""
prefix = prefix + [node.name]
for entry in node.kids:
if entry.kids:
self._list(files, prefix, entry)
else:
files.append(prefix[1:] + [entry.name])
def listdir(self):
"""
Return a list of streams stored in this file
"""
files = []
self._list(files, [], self.root)
return files
def _find(self, filename):
"""
Returns directory entry of given filename. (openstream helper)
Note: this method is case-insensitive.
filename: path of stream in storage tree (except root entry), either:
- a string using Unix path syntax, for example:
'storage_1/storage_1.2/stream'
- a list of storage filenames, path to the desired stream/storage.
Example: ['storage_1', 'storage_1.2', 'stream']
return: sid of requested filename
raise IOError if file not found
"""
# if filename is a string instead of a list, split it on slashes to
# convert to a list:
if isinstance(filename, basestring):
filename = filename.split('/')
# walk across storage tree, following given path:
node = self.root
for name in filename:
for kid in node.kids:
if kid.name.lower() == name.lower():
break
else:
raise IOError, "file not found"
node = kid
return node.sid
def openstream(self, filename):
"""
Open a stream as a read-only file object (StringIO).
filename: path of stream in storage tree (except root entry), either:
- a string using Unix path syntax, for example:
'storage_1/storage_1.2/stream'
- a list of storage filenames, path to the desired stream/storage.
Example: ['storage_1', 'storage_1.2', 'stream']
return: file object (read-only)
raise IOError if filename not found, or if this is not a stream.
"""
sid = self._find(filename)
entry = self.direntries[sid]
if entry.entry_type != STGTY_STREAM:
raise IOError, "this file is not a stream"
return self._open(entry.isectStart, entry.size)
def get_type(self, filename):
"""
Test if given filename exists as a stream or a storage in the OLE
container, and return its type.
filename: path of stream in storage tree (except root entry), either:
- a string using Unix path syntax, for example:
'storage_1/storage_1.2/stream'
- a list of storage filenames, path to the desired stream/storage.
Example: ['storage_1', 'storage_1.2', 'stream']
return: False if object does not exist, its entry type (>0) otherwise:
- STGTY_STREAM: a stream
- STGTY_STORAGE: a storage
- STGTY_ROOT: the root entry
"""
try:
sid = self._find(filename)
entry = self.direntries[sid]
return entry.entry_type
except:
return False
def get_rootentry_name(self):
"""
Return root entry name. Should usually be 'Root Entry' or 'R' in most
implementations.
"""
return self.root.name
def getproperties(self, filename):
"""
Return properties described in substream
filename: path of stream in storage tree (except root entry), either:
- a string using Unix path syntax, for example:
'storage_1/storage_1.2/stream'
- a list of storage filenames, path to the desired stream/storage.
Example: ['storage_1', 'storage_1.2', 'stream']
"""
fp = self.openstream(filename)
data = {}
# header
s = fp.read(28)
clsid = _clsid(s[8:24])
# format id
s = fp.read(20)
fmtid = _clsid(s[:16])
fp.seek(i32(s, 16))
# get section
s = "****" + fp.read(i32(fp.read(4))-4)
for i in range(i32(s, 4)):
id = i32(s, 8+i*8)
offset = i32(s, 12+i*8)
type = i32(s, offset)
# test for common types first (should perhaps use
# a dictionary instead?)
if type == VT_I2:
value = i16(s, offset+4)
if value >= 32768:
value = value - 65536
elif type == VT_UI2:
value = i16(s, offset+4)
elif type in (VT_I4, VT_ERROR):
value = i32(s, offset+4)
elif type == VT_UI4:
value = i32(s, offset+4) # FIXME
elif type in (VT_BSTR, VT_LPSTR):
count = i32(s, offset+4)
value = s[offset+8:offset+8+count-1]
elif type == VT_BLOB:
count = i32(s, offset+4)
value = s[offset+8:offset+8+count]
elif type == VT_LPWSTR:
count = i32(s, offset+4)
value = self._unicode(s[offset+8:offset+8+count*2])
elif type == VT_FILETIME:
value = long(i32(s, offset+4)) + (long(i32(s, offset+8))<<32)
# FIXME: this is a 64-bit int: "number of 100ns periods
# since Jan 1,1601". Should map this to Python time
value = value / 10000000L # seconds
elif type == VT_UI1:
value = ord(s[offset+4])
elif type == VT_CLSID:
value = _clsid(s[offset+4:offset+20])
elif type == VT_CF:
count = i32(s, offset+4)
value = s[offset+8:offset+8+count]
else:
value = None # everything else yields "None"
# FIXME: add support for VT_VECTOR
#print "%08x" % id, repr(value),
#print "(%s)" % VT[i32(s, offset) & 0xFFF]
data[id] = value
return data
#
# --------------------------------------------------------------------
# This script can be used to dump the directory of any OLE2 structured
# storage file.
if __name__ == "__main__":
import sys
# [PL] display quick usage info if launched from command-line
if len(sys.argv) <= 1:
print __doc__
print "Launched from command line, this script parses OLE files and prints info."
print ""
sys.exit("usage: OleFileIO_PL.py <file> [file2 ...]")
for filename in sys.argv[1:]:
## try:
ole = OleFileIO(filename, raise_defects=DEFECT_INCORRECT)
print "-" * 68
print filename
print "-" * 68
ole.dumpdirectory()
for streamname in ole.listdir():
if streamname[-1][0] == "\005":
print streamname, ": properties"
props = ole.getproperties(streamname)
props = props.items()
props.sort()
for k, v in props:
print " ", k, v
root = ole.get_rootentry_name()
print 'Root entry name: "%s"' % root
if ole.get_type('macros/vba'):
print "This may be a Word document with VBA macros."
## except IOError, v:
## print "***", "cannot read", file, "-", v
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