Source code for PIL.OleFileIO

#
# 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.
#

from __future__ import print_function

import io
import sys
from PIL import _binary
from PIL._util import isPath

if str is not bytes:
    long = int

i8 = _binary.i8
i16 = _binary.i16le
i32 = _binary.i32le


MAGIC = b'\320\317\021\340\241\261\032\341'

#
# --------------------------------------------------------------------
# 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 list(vars().items()):
    if k[:3] == "VT_":
        VT[v] = k

#
# --------------------------------------------------------------------
# Some common document types (root.clsid fields)

WORD_CLSID = "00020900-0000-0000-C000-000000000046"


#
# --------------------------------------------------------------------

class _OleStream(io.BytesIO):

    """OLE2 Stream

    Returns a read-only file object which can be used to read
    the contents of a OLE stream.  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.
    """

    # 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):

        data = []

        while sect != -2: # 0xFFFFFFFEL:
            fp.seek(offset + sectorsize * sect)
            data.append(fp.read(sectorsize))
            sect = fat[sect]

        data = b"".join(data)

        # print len(data), size

        io.BytesIO.__init__(self, data[:size])

#
# --------------------------------------------------------------------

# FIXME: should add a counter in here to avoid looping forever
# if the tree is broken.

class _OleDirectoryEntry:

    """OLE2 Directory Entry

    Encapsulates a stream directory entry.  Note that the
    constructor builds a tree of all subentries, so we only
    have to call it with the root object.
    """

    def __init__(self, sidlist, sid):

        # store directory parameters.  the caller provides
        # a complete list of directory entries, as read from
        # the directory stream.

        name, type, sect, size, sids, clsid = sidlist[sid]

        self.sid  = sid
        self.name = name
        self.type = type # 1=storage 2=stream
        self.sect = sect
        self.size = size
        self.clsid = clsid

        # process child nodes, if any

        self.kids = []

        sid = sidlist[sid][4][2]

        if sid != -1:

            # the directory entries are organized as a red-black tree.
            # the following piece of code does an ordered traversal of
            # such a tree (at least that's what I hope ;-)

            stack = [self.sid]

            # start at leftmost position

            left, right, child = sidlist[sid][4]

            while left != -1: # 0xFFFFFFFFL:
                stack.append(sid)
                sid = left
                left, right, child = sidlist[sid][4]

            while sid != self.sid:

                self.kids.append(_OleDirectoryEntry(sidlist, sid))

                # try to move right
                left, right, child = sidlist[sid][4]
                if right != -1: # 0xFFFFFFFFL:
                    # and then back to the left
                    sid = right
                    while True:
                        left, right, child = sidlist[sid][4]
                        if left == -1: # 0xFFFFFFFFL:
                            break
                        stack.append(sid)
                        sid = left
                else:
                    # couldn't move right; move up instead
                    while True:
                        ptr = stack[-1]
                        del stack[-1]
                        left, right, child = sidlist[ptr][4]
                        if right != sid:
                            break
                        sid = right
                    left, right, child = sidlist[sid][4]
                    if right != ptr:
                        sid = ptr

            # in the OLE file, entries are sorted on (length, name).
            # for convenience, we sort them on name instead.

            self.kids.sort()

    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.type], end=' ')
        if self.type in (2, 5):
            print(self.size, "bytes", end=' ')
        print()
        if self.type in (1, 5) and self.clsid:
            print(" "*tab + "{%s}" % self.clsid)

        for kid in self.kids:
            kid.dump(tab + 2)

#
# --------------------------------------------------------------------

##
# 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.

[docs]class OleFileIO: """OLE container object This class encapsulates the interface to an OLE 2 structured storage file. Use the listdir and 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): if filename: self.open(filename) ## # Open an OLE2 file.
[docs] def open(self, filename): """Open an OLE2 file""" if isPath(filename): self.fp = open(filename, "rb") else: self.fp = filename header = self.fp.read(512) if len(header) != 512 or header[:8] != MAGIC: raise IOError("not an OLE2 structured storage file") # file clsid (probably never used, so we don't store it) clsid = self._clsid(header[8:24]) # FIXME: could check version and byte order fields 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 sidlist (ordered by id) # and the root (ordered by hierarchy) members. self.loaddirectory(i32(header, 48)) self.ministream = None self.minifatsect = i32(header, 60)
[docs] 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 (FIXME: not yet implemented) sect = header[76:512] fat = [] for i in range(0, len(sect), 4): ix = i32(sect, i) if ix == -2 or ix == -1: # ix == 0xFFFFFFFEL or ix == 0xFFFFFFFFL: break s = self.getsect(ix) fat = fat + [i32(s, i) for i in range(0, len(s), 4)] self.fat = fat
[docs] 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() self.minifat = [i32(s, i) for i in range(0, len(s), 4)]
[docs] def getsect(self, sect): # Read given sector self.fp.seek(512 + self.sectorsize * sect) return self.fp.read(self.sectorsize)
def _unicode(self, s): # Map unicode string to Latin 1 if bytes is str: # Old version tried to produce a Latin-1 str return s.decode('utf-16').encode('latin-1', 'replace') else: # Provide actual Unicode string return s.decode('utf-16')
[docs] def loaddirectory(self, sect): # Load the directory. The directory is stored in a standard # substream, independent of its size. # read directory stream fp = self._open(sect) # create list of sid entries self.sidlist = [] while True: entry = fp.read(128) if not entry: break type = i8(entry[66]) name = self._unicode(entry[0:0+i16(entry, 64)]) ptrs = i32(entry, 68), i32(entry, 72), i32(entry, 76) sect, size = i32(entry, 116), i32(entry, 120) clsid = self._clsid(entry[80:96]) self.sidlist.append((name, type, sect, size, ptrs, clsid)) # create hierarchical list of directory entries self.root = _OleDirectoryEntry(self.sidlist, 0)
[docs] def dumpdirectory(self): # Dump directory (for debugging only) self.root.dump()
def _clsid(self, clsid): 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(i8, clsid[8:16])))) def _list(self, files, prefix, node): # listdir helper 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 _find(self, filename): # openstream helper node = self.root for name in filename: for kid in node.kids: if kid.name == name: break else: raise IOError("file not found") node = kid return node.sid def _open(self, start, size = 0x7FFFFFFF): # openstream helper. if size < self.minisectorcutoff: # ministream object if not self.ministream: self.loadminifat() self.ministream = self._open(self.sidlist[0][2]) return _OleStream(self.ministream, start, size, 0, self.minisectorsize, self.minifat) # standard stream return _OleStream(self.fp, start, size, 512, self.sectorsize, self.fat) ## # Returns a list of streams stored in this file.
[docs] def listdir(self): """Return a list of streams stored in this file""" files = [] self._list(files, [], self.root) return files ## # Opens a stream as a read-only file object.
[docs] def openstream(self, filename): """Open a stream as a read-only file object""" slot = self._find(filename) name, type, sect, size, sids, clsid = self.sidlist[slot] if type != 2: raise IOError("this file is not a stream") return self._open(sect, size) ## # Gets a list of properties described in substream.
[docs] def getproperties(self, filename): """Return properties described in substream""" fp = self.openstream(filename) data = {} # header s = fp.read(28) clsid = self._clsid(s[8:24]) # format id s = fp.read(20) fmtid = self._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 // 10000000 # seconds elif type == VT_UI1: value = i8(s[offset+4]) elif type == VT_CLSID: value = self._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 for file in sys.argv[1:]: try: ole = OleFileIO(file) print("-" * 68) print(file) print("-" * 68) ole.dumpdirectory() for file in ole.listdir(): if file[-1][0] == "\005": print(file) props = ole.getproperties(file) props = sorted(props.items()) for k, v in props: print(" ", k, v) except IOError as v: print("***", "cannot read", file, "-", v)

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