Exemple #1
0
    def readObjectHeader(self, stream):
        # Should never be necessary to read out whitespace, since the
        # cross-reference table should put us in the right spot to read the
        # object header.  In reality... some files have stupid cross reference
        # tables that are off by whitespace bytes.
        extra = False
        utils.skipOverComment(stream)

        extra |= utils.skipOverWhitespace(stream)
        stream.seek(-1, 1)

        idnum = readUntilWhitespace(stream)

        extra |= utils.skipOverWhitespace(stream)
        stream.seek(-1, 1)

        generation = readUntilWhitespace(stream)
        stream.read(3)
        readNonWhitespace(stream)
        stream.seek(-1, 1)
        if (extra and self.strict):
            #not a fatal error
            warnings.warn(
                "Superfluous whitespace found in "
                "object header %s %s" % (idnum, generation),
                utils.PdfReadWarning)
        return int(idnum), int(generation)
Exemple #2
0
    def readFromStream(stream, pdf):
        debug = False
        tmp = stream.read(2)
        if tmp != b_("<<"):
            raise utils.PdfReadError(
                "Dictionary read error at byte %s: stream must begin with '<<'"
                % utils.hexStr(stream.tell()))
        data = {}
        while True:
            tok = readNonWhitespace(stream)
            if tok == b_('\x00'):
                continue
            elif tok == b_('%'):
                stream.seek(-1, 1)
                skipOverComment(stream)
                continue
            if not tok:
                # stream has truncated prematurely
                raise PdfStreamError("Stream has ended unexpectedly")

            if debug: print(("Tok:", tok))
            if tok == b_(">"):
                stream.read(1)
                break
            stream.seek(-1, 1)
            key = readObject(stream, pdf)
            tok = readNonWhitespace(stream)
            stream.seek(-1, 1)
            value = readObject(stream, pdf)
            if not data.get(key):
                data[key] = value
            elif pdf.strict:
                # multiple definitions of key not permitted
                raise utils.PdfReadError("Multiple definitions in dictionary at byte %s for key %s" \
                                           % (utils.hexStr(stream.tell()), key))
            else:
                warnings.warn("Multiple definitions in dictionary at byte %s for key %s" \
                                           % (utils.hexStr(stream.tell()), key), utils.PdfReadWarning)

        pos = stream.tell()
        s = readNonWhitespace(stream)
        if s == b_('s') and stream.read(5) == b_('tream'):
            eol = stream.read(1)
            # odd PDF file output has spaces after 'stream' keyword but before EOL.
            # patch provided by Danial Sandler
            while eol == b_(' '):
                eol = stream.read(1)
            assert eol in (b_("\n"), b_("\r"))
            if eol == b_("\r"):
                # read \n after
                if stream.read(1) != b_('\n'):
                    stream.seek(-1, 1)
            # this is a stream object, not a dictionary
            assert "/Length" in data
            length = data["/Length"]
            if debug: print(data)
            if isinstance(length, IndirectObject):
                t = stream.tell()
                length = pdf.getObject(length)
                stream.seek(t, 0)
            data["__streamdata__"] = stream.read(length)
            if debug: print("here")
            #if debug: print(binascii.hexlify(data["__streamdata__"]))
            e = readNonWhitespace(stream)
            ndstream = stream.read(8)
            if (e + ndstream) != b_("endstream"):
                # (sigh) - the odd PDF file has a length that is too long, so
                # we need to read backwards to find the "endstream" ending.
                # ReportLab (unknown version) generates files with this bug,
                # and Python users into PDF files tend to be our audience.
                # we need to do this to correct the streamdata and chop off
                # an extra character.
                pos = stream.tell()
                stream.seek(-10, 1)
                end = stream.read(9)
                if end == b_("endstream"):
                    # we found it by looking back one character further.
                    data["__streamdata__"] = data["__streamdata__"][:-1]
                else:
                    if debug: print(("E", e, ndstream, debugging.toHex(end)))
                    stream.seek(pos, 0)
                    raise utils.PdfReadError(
                        "Unable to find 'endstream' marker after stream at byte %s."
                        % utils.hexStr(stream.tell()))
        else:
            stream.seek(pos, 0)
        if "__streamdata__" in data:
            return StreamObject.initializeFromDictionary(data)
        else:
            retval = DictionaryObject()
            retval.update(data)
            return retval
Exemple #3
0
    def readFromStream(stream, pdf):
        debug = False
        tmp = stream.read(2)
        if tmp != b_("<<"):
            raise utils.PdfReadError("Dictionary read error at byte %s: stream must begin with '<<'" % utils.hexStr(stream.tell()))
        data = {}
        while True:
            tok = readNonWhitespace(stream)
            if tok == b_('\x00'):
                continue
            elif tok == b_('%'):
                stream.seek(-1, 1)
                skipOverComment(stream)
                continue
            if not tok:
                # stream has truncated prematurely
                raise PdfStreamError("Stream has ended unexpectedly")

            if debug: print(("Tok:", tok))
            if tok == b_(">"):
                stream.read(1)
                break
            stream.seek(-1, 1)
            key = readObject(stream, pdf)
            tok = readNonWhitespace(stream)
            stream.seek(-1, 1)
            value = readObject(stream, pdf)
            if not data.get(key):
                data[key] = value
            elif pdf.strict:
                # multiple definitions of key not permitted
                raise utils.PdfReadError("Multiple definitions in dictionary at byte %s for key %s" \
                                           % (utils.hexStr(stream.tell()), key))
            else:
                warnings.warn("Multiple definitions in dictionary at byte %s for key %s" \
                                           % (utils.hexStr(stream.tell()), key), utils.PdfReadWarning)

        pos = stream.tell()
        s = readNonWhitespace(stream)
        if s == b_('s') and stream.read(5) == b_('tream'):
            eol = stream.read(1)
            # odd PDF file output has spaces after 'stream' keyword but before EOL.
            # patch provided by Danial Sandler
            while eol == b_(' '):
                eol = stream.read(1)
            assert eol in (b_("\n"), b_("\r"))
            if eol == b_("\r"):
                # read \n after
                if stream.read(1)  != b_('\n'):
                    stream.seek(-1, 1)
            # this is a stream object, not a dictionary
            assert "/Length" in data
            length = data["/Length"]
            if debug: print(data)
            if isinstance(length, IndirectObject):
                t = stream.tell()
                length = pdf.getObject(length)
                stream.seek(t, 0)
            data["__streamdata__"] = stream.read(length)
            if debug: print("here")
            #if debug: print(binascii.hexlify(data["__streamdata__"]))
            e = readNonWhitespace(stream)
            ndstream = stream.read(8)
            if (e + ndstream) != b_("endstream"):
                # (sigh) - the odd PDF file has a length that is too long, so
                # we need to read backwards to find the "endstream" ending.
                # ReportLab (unknown version) generates files with this bug,
                # and Python users into PDF files tend to be our audience.
                # we need to do this to correct the streamdata and chop off
                # an extra character.
                pos = stream.tell()
                stream.seek(-10, 1)
                end = stream.read(9)
                if end == b_("endstream"):
                    # we found it by looking back one character further.
                    data["__streamdata__"] = data["__streamdata__"][:-1]
                else:
                    if debug: print(("E", e, ndstream, debugging.toHex(end)))
                    stream.seek(pos, 0)
                    raise utils.PdfReadError("Unable to find 'endstream' marker after stream at byte %s." % utils.hexStr(stream.tell()))
        else:
            stream.seek(pos, 0)
        if "__streamdata__" in data:
            return StreamObject.initializeFromDictionary(data)
        else:
            retval = DictionaryObject()
            retval.update(data)
            return retval
Exemple #4
-4
    def readObjectHeader(self, stream):
        # Should never be necessary to read out whitespace, since the
        # cross-reference table should put us in the right spot to read the
        # object header.  In reality... some files have stupid cross reference
        # tables that are off by whitespace bytes.
        extra = False
        utils.skipOverComment(stream)

        extra |= utils.skipOverWhitespace(stream)
        stream.seek(-1, 1)

        idnum = readUntilWhitespace(stream)

        extra |= utils.skipOverWhitespace(stream)
        stream.seek(-1, 1)

        generation = readUntilWhitespace(stream)
        stream.read(3)
        readNonWhitespace(stream)
        stream.seek(-1, 1)
        if (extra and self.strict):
            #not a fatal error
            warnings.warn("Superfluous whitespace found in "
                          "object header %s %s" % (idnum, generation),
                          utils.PdfReadWarning)
        return int(idnum), int(generation)