# Copyright (c) 2006, Mathieu Fenniak
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * 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.
# * The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
import binascii
import codecs
import hashlib
import re
from binascii import unhexlify
from math import log10
from typing import Any, Callable, ClassVar, Dict, Optional, Sequence, Union, cast
from .._codecs import _pdfdoc_encoding_rev
from .._protocols import PdfObjectProtocol, PdfWriterProtocol
from .._utils import (
StreamType,
b_,
deprecate_no_replacement,
logger_warning,
read_non_whitespace,
read_until_regex,
str_,
)
from ..errors import STREAM_TRUNCATED_PREMATURELY, PdfReadError, PdfStreamError
__author__ = "Mathieu Fenniak"
__author_email__ = "biziqe@mathieu.fenniak.net"
class PdfObject(PdfObjectProtocol):
# function for calculating a hash value
hash_func: Callable[..., "hashlib._Hash"] = hashlib.sha1
indirect_reference: Optional["IndirectObject"]
def hash_value_data(self) -> bytes:
return ("%s" % self).encode()
def hash_value(self) -> bytes:
return (
"%s:%s"
% (
self.__class__.__name__,
self.hash_func(self.hash_value_data()).hexdigest(),
)
).encode()
def clone(
self,
pdf_dest: PdfWriterProtocol,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "PdfObject":
"""
Clone object into pdf_dest (PdfWriterProtocol which is an interface for PdfWriter).
By default, this method will call ``_reference_clone`` (see ``_reference``).
Args:
pdf_dest: Target to clone to.
force_duplicate: By default, if the object has already been cloned and referenced,
the copy will be returned; when ``True``, a new copy will be created.
(Default value = ``False``)
ignore_fields: List/tuple of field names (for dictionaries) that will be ignored
during cloning (applies to children duplication as well). If fields are to be
considered for a limited number of levels, you have to add it as integer, for
example ``[1,"/B","/TOTO"]`` means that ``"/B"`` will be ignored at the first
level only but ``"/TOTO"`` on all levels.
Returns:
The cloned PdfObject
"""
raise NotImplementedError(
f"{self.__class__.__name__} does not implement .clone so far"
)
def _reference_clone(
self, clone: Any, pdf_dest: PdfWriterProtocol, force_duplicate: bool = False
) -> PdfObjectProtocol:
"""
Reference the object within the _objects of pdf_dest only if
indirect_reference attribute exists (which means the objects was
already identified in xref/xobjstm) if object has been already
referenced do nothing.
Args:
clone:
pdf_dest:
Returns:
The clone
"""
try:
if not force_duplicate and clone.indirect_reference.pdf == pdf_dest:
return clone
except Exception:
pass
# if hasattr(clone, "indirect_reference"):
try:
ind = self.indirect_reference
except AttributeError:
return clone
i = len(pdf_dest._objects) + 1
if ind is not None:
if id(ind.pdf) not in pdf_dest._id_translated:
pdf_dest._id_translated[id(ind.pdf)] = {}
pdf_dest._id_translated[id(ind.pdf)]["PreventGC"] = ind.pdf # type: ignore
if (
not force_duplicate
and ind.idnum in pdf_dest._id_translated[id(ind.pdf)]
):
obj = pdf_dest.get_object(
pdf_dest._id_translated[id(ind.pdf)][ind.idnum]
)
assert obj is not None
return obj
pdf_dest._id_translated[id(ind.pdf)][ind.idnum] = i
pdf_dest._objects.append(clone)
clone.indirect_reference = IndirectObject(i, 0, pdf_dest)
return clone
def get_object(self) -> Optional["PdfObject"]:
"""Resolve indirect references."""
return self
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
raise NotImplementedError
class NullObject(PdfObject):
def clone(
self,
pdf_dest: PdfWriterProtocol,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "NullObject":
"""Clone object into pdf_dest."""
return cast(
"NullObject", self._reference_clone(NullObject(), pdf_dest, force_duplicate)
)
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(b"null")
@staticmethod
def read_from_stream(stream: StreamType) -> "NullObject":
nulltxt = stream.read(4)
if nulltxt != b"null":
raise PdfReadError("Could not read Null object")
return NullObject()
def __repr__(self) -> str:
return "NullObject"
class BooleanObject(PdfObject):
def __init__(self, value: Any) -> None:
self.value = value
def clone(
self,
pdf_dest: PdfWriterProtocol,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "BooleanObject":
"""Clone object into pdf_dest."""
return cast(
"BooleanObject",
self._reference_clone(BooleanObject(self.value), pdf_dest, force_duplicate),
)
def __eq__(self, __o: object) -> bool:
if isinstance(__o, BooleanObject):
return self.value == __o.value
elif isinstance(__o, bool):
return self.value == __o
else:
return False
def __repr__(self) -> str:
return "True" if self.value else "False"
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
if self.value:
stream.write(b"true")
else:
stream.write(b"false")
@staticmethod
def read_from_stream(stream: StreamType) -> "BooleanObject":
word = stream.read(4)
if word == b"true":
return BooleanObject(True)
elif word == b"fals":
stream.read(1)
return BooleanObject(False)
else:
raise PdfReadError("Could not read Boolean object")
class IndirectObject(PdfObject):
def __init__(self, idnum: int, generation: int, pdf: Any) -> None: # PdfReader
self.idnum = idnum
self.generation = generation
self.pdf = pdf
def clone(
self,
pdf_dest: PdfWriterProtocol,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "IndirectObject":
"""Clone object into pdf_dest."""
if self.pdf == pdf_dest and not force_duplicate:
# Already duplicated and no extra duplication required
return self
if id(self.pdf) not in pdf_dest._id_translated:
pdf_dest._id_translated[id(self.pdf)] = {}
if self.idnum in pdf_dest._id_translated[id(self.pdf)]:
dup = pdf_dest.get_object(pdf_dest._id_translated[id(self.pdf)][self.idnum])
if force_duplicate:
assert dup is not None
assert dup.indirect_reference is not None
idref = dup.indirect_reference
return IndirectObject(idref.idnum, idref.generation, idref.pdf)
else:
obj = self.get_object()
# case observed : a pointed object can not be found
if obj is None:
# this normally
obj = NullObject()
assert isinstance(self, (IndirectObject,))
obj.indirect_reference = self
dup = pdf_dest._add_object(
obj.clone(pdf_dest, force_duplicate, ignore_fields)
)
# asserts added to prevent errors in mypy
assert dup is not None
assert dup.indirect_reference is not None
return dup.indirect_reference
@property
def indirect_reference(self) -> "IndirectObject": # type: ignore[override]
return self
def get_object(self) -> Optional["PdfObject"]:
return self.pdf.get_object(self)
def __deepcopy__(self, memo: Any) -> "IndirectObject":
return IndirectObject(self.idnum, self.generation, self.pdf)
def _get_object_with_check(self) -> Optional["PdfObject"]:
o = self.get_object()
# the check is done here to not slow down get_object()
if isinstance(o, IndirectObject):
raise PdfStreamError(
f"{self.__repr__()} references an IndirectObject {o.__repr__()}"
)
return o
def __getattr__(self, name: str) -> Any:
# Attribute not found in object: look in pointed object
try:
return getattr(self._get_object_with_check(), name)
except AttributeError:
raise AttributeError(
f"No attribute {name} found in IndirectObject or pointed object"
)
def __getitem__(self, key: Any) -> Any:
# items should be extracted from pointed Object
return self._get_object_with_check()[key] # type: ignore
def __str__(self) -> str:
# in this case we are looking for the pointed data
return self.get_object().__str__()
def __repr__(self) -> str:
return f"IndirectObject({self.idnum!r}, {self.generation!r}, {id(self.pdf)})"
def __eq__(self, other: object) -> bool:
return (
other is not None
and isinstance(other, IndirectObject)
and self.idnum == other.idnum
and self.generation == other.generation
and self.pdf is other.pdf
)
def __ne__(self, other: object) -> bool:
return not self.__eq__(other)
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(f"{self.idnum} {self.generation} R".encode())
@staticmethod
def read_from_stream(stream: StreamType, pdf: Any) -> "IndirectObject": # PdfReader
idnum = b""
while True:
tok = stream.read(1)
if not tok:
raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
if tok.isspace():
break
idnum += tok
generation = b""
while True:
tok = stream.read(1)
if not tok:
raise PdfStreamError(STREAM_TRUNCATED_PREMATURELY)
if tok.isspace():
if not generation:
continue
break
generation += tok
r = read_non_whitespace(stream)
if r != b"R":
raise PdfReadError(
f"Error reading indirect object reference at byte {hex(stream.tell())}"
)
return IndirectObject(int(idnum), int(generation), pdf)
FLOAT_WRITE_PRECISION = 8 # shall be min 5 digits max, allow user adj
class FloatObject(float, PdfObject):
def __new__(
cls, value: Union[str, Any] = "0.0", context: Optional[Any] = None
) -> "FloatObject":
try:
value = float(str_(value))
return float.__new__(cls, value)
except Exception as e:
# If this isn't a valid decimal (happens in malformed PDFs)
# fallback to 0
logger_warning(
f"{e} : FloatObject ({value}) invalid; use 0.0 instead", __name__
)
return float.__new__(cls, 0.0)
def clone(
self,
pdf_dest: Any,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "FloatObject":
"""Clone object into pdf_dest."""
return cast(
"FloatObject",
self._reference_clone(FloatObject(self), pdf_dest, force_duplicate),
)
def myrepr(self) -> str:
if self == 0:
return "0.0"
nb = FLOAT_WRITE_PRECISION - int(log10(abs(self)))
s = f"{self:.{max(1,nb)}f}".rstrip("0").rstrip(".")
return s
def __repr__(self) -> str:
return self.myrepr() # repr(float(self))
def as_numeric(self) -> float:
return float(self)
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(self.myrepr().encode("utf8"))
class NumberObject(int, PdfObject):
NumberPattern = re.compile(b"[^+-.0-9]")
def __new__(cls, value: Any) -> "NumberObject":
try:
return int.__new__(cls, int(value))
except ValueError:
logger_warning(f"NumberObject({value}) invalid; use 0 instead", __name__)
return int.__new__(cls, 0)
def clone(
self,
pdf_dest: Any,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "NumberObject":
"""Clone object into pdf_dest."""
return cast(
"NumberObject",
self._reference_clone(NumberObject(self), pdf_dest, force_duplicate),
)
def as_numeric(self) -> int:
return int(repr(self).encode("utf8"))
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(repr(self).encode("utf8"))
@staticmethod
def read_from_stream(stream: StreamType) -> Union["NumberObject", "FloatObject"]:
num = read_until_regex(stream, NumberObject.NumberPattern)
if num.find(b".") != -1:
return FloatObject(num)
return NumberObject(num)
class ByteStringObject(bytes, PdfObject):
"""
Represents a string object where the text encoding could not be determined.
This occurs quite often, as the PDF spec doesn't provide an alternate way to
represent strings -- for example, the encryption data stored in files (like
/O) is clearly not text, but is still stored in a "String" object.
"""
def clone(
self,
pdf_dest: Any,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "ByteStringObject":
"""Clone object into pdf_dest."""
return cast(
"ByteStringObject",
self._reference_clone(
ByteStringObject(bytes(self)), pdf_dest, force_duplicate
),
)
@property
def original_bytes(self) -> bytes:
"""For compatibility with TextStringObject.original_bytes."""
return self
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(b"<")
stream.write(binascii.hexlify(self))
stream.write(b">")
class TextStringObject(str, PdfObject): # noqa: SLOT000
"""
A string object that has been decoded into a real unicode string.
If read from a PDF document, this string appeared to match the
PDFDocEncoding, or contained a UTF-16BE BOM mark to cause UTF-16 decoding
to occur.
"""
autodetect_pdfdocencoding: bool
autodetect_utf16: bool
utf16_bom: bytes
def __new__(cls, value: Any) -> "TextStringObject":
if isinstance(value, bytes):
value = value.decode("charmap")
o = str.__new__(cls, value)
o.autodetect_utf16 = False
o.autodetect_pdfdocencoding = False
o.utf16_bom = b""
if value.startswith(("\xfe\xff", "\xff\xfe")):
o.autodetect_utf16 = True
o.utf16_bom = value[:2].encode("charmap")
else:
try:
encode_pdfdocencoding(o)
o.autodetect_pdfdocencoding = True
except UnicodeEncodeError:
o.autodetect_utf16 = True
return o
def clone(
self,
pdf_dest: Any,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "TextStringObject":
"""Clone object into pdf_dest."""
obj = TextStringObject(self)
obj.autodetect_pdfdocencoding = self.autodetect_pdfdocencoding
obj.autodetect_utf16 = self.autodetect_utf16
obj.utf16_bom = self.utf16_bom
return cast(
"TextStringObject", self._reference_clone(obj, pdf_dest, force_duplicate)
)
@property
def original_bytes(self) -> bytes:
"""
It is occasionally possible that a text string object gets created where
a byte string object was expected due to the autodetection mechanism --
if that occurs, this "original_bytes" property can be used to
back-calculate what the original encoded bytes were.
"""
return self.get_original_bytes()
def get_original_bytes(self) -> bytes:
# We're a text string object, but the library is trying to get our raw
# bytes. This can happen if we auto-detected this string as text, but
# we were wrong. It's pretty common. Return the original bytes that
# would have been used to create this object, based upon the autodetect
# method.
if self.autodetect_utf16:
if self.utf16_bom == codecs.BOM_UTF16_LE:
return codecs.BOM_UTF16_LE + self.encode("utf-16le")
elif self.utf16_bom == codecs.BOM_UTF16_BE:
return codecs.BOM_UTF16_BE + self.encode("utf-16be")
else:
return self.encode("utf-16be")
elif self.autodetect_pdfdocencoding:
return encode_pdfdocencoding(self)
else:
raise Exception("no information about original bytes") # pragma: no cover
def get_encoded_bytes(self) -> bytes:
# Try to write the string out as a PDFDocEncoding encoded string. It's
# nicer to look at in the PDF file. Sadly, we take a performance hit
# here for trying...
try:
if self.autodetect_utf16:
raise UnicodeEncodeError("", "forced", -1, -1, "")
bytearr = encode_pdfdocencoding(self)
except UnicodeEncodeError:
if self.utf16_bom == codecs.BOM_UTF16_LE:
bytearr = codecs.BOM_UTF16_LE + self.encode("utf-16le")
elif self.utf16_bom == codecs.BOM_UTF16_BE:
bytearr = codecs.BOM_UTF16_BE + self.encode("utf-16be")
else:
bytearr = self.encode("utf-16be")
return bytearr
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
bytearr = self.get_encoded_bytes()
stream.write(b"(")
for c in bytearr:
if not chr(c).isalnum() and c != b" ":
# This:
# stream.write(rf"\{c:0>3o}".encode())
# gives
# https://github.com/davidhalter/parso/issues/207
stream.write(("\\%03o" % c).encode())
else:
stream.write(b_(chr(c)))
stream.write(b")")
class NameObject(str, PdfObject): # noqa: SLOT000
delimiter_pattern = re.compile(rb"\s+|[\(\)<>\[\]{}/%]")
surfix = b"/"
renumber_table: ClassVar[Dict[str, bytes]] = {
"#": b"#23",
"(": b"#28",
")": b"#29",
"/": b"#2F",
"%": b"#25",
**{chr(i): f"#{i:02X}".encode() for i in range(33)},
}
def clone(
self,
pdf_dest: Any,
force_duplicate: bool = False,
ignore_fields: Optional[Sequence[Union[str, int]]] = (),
) -> "NameObject":
"""Clone object into pdf_dest."""
return cast(
"NameObject",
self._reference_clone(NameObject(self), pdf_dest, force_duplicate),
)
def write_to_stream(
self, stream: StreamType, encryption_key: Union[None, str, bytes] = None
) -> None:
if encryption_key is not None: # deprecated
deprecate_no_replacement(
"the encryption_key parameter of write_to_stream", "5.0.0"
)
stream.write(self.renumber())
def renumber(self) -> bytes:
out = self[0].encode("utf-8")
if out != b"/":
deprecate_no_replacement(
f"Incorrect first char in NameObject, should start with '/': ({self})",
"6.0.0",
)
for c in self[1:]:
if c > "~":
for x in c.encode("utf-8"):
out += f"#{x:02X}".encode()
else:
try:
out += self.renumber_table[c]
except KeyError:
out += c.encode("utf-8")
return out
@staticmethod
def unnumber(sin: bytes) -> bytes:
i = sin.find(b"#", 0)
while i >= 0:
try:
sin = sin[:i] + unhexlify(sin[i + 1 : i + 3]) + sin[i + 3 :]
i = sin.find(b"#", i + 1)
except ValueError:
# if the 2 characters after # can not be converted to hex
# we change nothing and carry on
i = i + 1
return sin
CHARSETS = ("utf-8", "gbk", "latin1")
@staticmethod
def read_from_stream(stream: StreamType, pdf: Any) -> "NameObject": # PdfReader
name = stream.read(1)
if name != NameObject.surfix:
raise PdfReadError("name read error")
name += read_until_regex(stream, NameObject.delimiter_pattern)
try:
# Name objects should represent irregular characters
# with a '#' followed by the symbol's hex number
name = NameObject.unnumber(name)
for enc in NameObject.CHARSETS:
try:
ret = name.decode(enc)
return NameObject(ret)
except Exception:
pass
raise UnicodeDecodeError("", name, 0, 0, "Code Not Found")
except (UnicodeEncodeError, UnicodeDecodeError) as e:
if not pdf.strict:
logger_warning(
f"Illegal character in NameObject ({name!r}), "
"you may need to adjust NameObject.CHARSETS",
__name__,
)
return NameObject(name.decode("charmap"))
else:
raise PdfReadError(
f"Illegal character in NameObject ({name!r}). "
"You may need to adjust NameObject.CHARSETS.",
) from e
def encode_pdfdocencoding(unicode_string: str) -> bytes:
retval = bytearray()
for c in unicode_string:
try:
retval += b_(chr(_pdfdoc_encoding_rev[c]))
except KeyError:
raise UnicodeEncodeError(
"pdfdocencoding", c, -1, -1, "does not exist in translation table"
)
return bytes(retval)
