release v2.0.14

borb/io/read/any_object_transformer.py

@@ -31,7 +31,7 @@
 from borb.io.read.primitive.string_transformer import StringTransformer
 from borb.io.read.reference.reference_transformer import ReferenceTransformer
 from borb.io.read.reference.xref_transformer import XREFTransformer
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/encryption/rc4.py

@@ -32,7 +32,7 @@ def __init__(self):
         self._p: int = 0
         self._q: int = 0
 
-    def set_key(self, key: bytes):
+    def _set_key(self, key: bytes):
         self._state = [n for n in range(256)]
         self._p = 0
         self._q = 0
@@ -54,5 +54,12 @@ def _byte_generator(self):
         return self._state[(self._state[self._p] + self._state[self._q]) % 256]
 
     def encrypt(self, key: bytes, input: bytes):
-        self.set_key(key)
+        """
+        This function encrypts a given byte array with a given key,
+        returning the encrypted bytes.
+        :param key:     the key to be used for encrypting
+        :param input:   the input byte array to be encrypted
+        :return:        the encrypted bytes
+        """
+        self._set_key(key)
         return bytes([p ^ self._byte_generator() for p in input])

borb/io/read/encryption/standard_security_handler.py

@@ -12,14 +12,14 @@
 
 from borb.io.read.encryption.rc4 import RC4
 from borb.io.read.types import (
-    String,
+    AnyPDFType,
+    Boolean,
     Decimal,
     HexadecimalString,
-    Boolean,
-    AnyPDFType,
+    Name,
     Reference,
     Stream,
-    Name,
+    String,
 )
 
 
@@ -59,27 +59,40 @@ def __init__(
         # used in determining whether to prompt the user for a password and, if so,
         # whether a valid user or owner password was entered. For more
         # information, see 7.6.3.4, "Password Algorithms."
-        self._u: bytes = StandardSecurityHandler._str_to_bytes(
-            StandardSecurityHandler._unescape_pdf_syntax(encryption_dictionary.get("U"))
+        self._u: bytes = (
+            StandardSecurityHandler._str_to_bytes(
+                StandardSecurityHandler._unescape_pdf_syntax(
+                    encryption_dictionary.get("U")
+                )
+            )
+            or b""
         )
+        assert self._u is not None
         assert len(self._u) == 32
 
         # (Required) A 32-byte string, based on both the owner and user passwords,
         # that shall be used in computing the encryption key and in determining
         # whether a valid owner password was entered. For more information, see
         # 7.6.3.3, "Encryption Key Algorithm," and 7.6.3.4, "Password Algorithms."
-        self._o: bytes = StandardSecurityHandler._str_to_bytes(
-            StandardSecurityHandler._unescape_pdf_syntax(encryption_dictionary.get("O"))
+        self._o: bytes = (
+            StandardSecurityHandler._str_to_bytes(
+                StandardSecurityHandler._unescape_pdf_syntax(
+                    encryption_dictionary.get("O")
+                )
+            )
+            or b""
         )
+        assert self._o is not None
         assert len(self._o) == 32
 
         # /ID
-        trailer: dict = encryption_dictionary.get_parent()
+        trailer: dict = encryption_dictionary.get_parent()  # type: ignore [attr-defined]
         if "ID" in trailer:
             self._document_id: bytes = trailer["ID"][0].get_content_bytes()
 
         # (Required) A set of flags specifying which operations shall be permitted
         # when the document is opened with user access (see Table 22).
+        assert "P" in encryption_dictionary
         self._permissions: int = int(encryption_dictionary.get("P"))
 
         # (Optional; PDF 1.4; only if V is 2 or 3) The length of the encryption key, in bits.
@@ -112,15 +125,19 @@ def __init__(
             password = bytes(owner_password, encoding="charmap")
 
         # calculate encryption_key
+        assert password is not None
         self._encryption_key: bytes = self._compute_encryption_key(password)
 
-    def _encrypt_data(self, object: AnyPDFType) -> None:
+    def _encrypt_data(self, object: AnyPDFType) -> AnyPDFType:
         # a) Obtain the object number and generation number from the object identifier of the string or stream to be
         # encrypted (see 7.3.10, "Indirect Objects"). If the string is a direct object, use the identifier of the indirect
         # object containing it.
-        reference: typing.Optional[Reference] = object.get_reference()
+        reference: typing.Optional[Reference] = object.get_reference()  # type: ignore [union-attr]
         if reference is None:
-            reference = object.get_parent().get_reference()
+            reference = object.get_parent().get_reference()  # type: ignore [union-attr]
+        assert reference is not None
+        assert reference.object_number is not None
+        assert reference.generation_number is not None
         object_number: int = reference.object_number
         generation_number: int = reference.generation_number
 
@@ -153,24 +170,27 @@ def _encrypt_data(self, object: AnyPDFType) -> None:
         # The output is the encrypted data to be stored in the PDF file.
         n_plus_5: int = min(16, n + 5)
         if isinstance(object, String):
-            new_content_bytes: bytes = RC4().encrypt(
+            str_new_content_bytes: bytes = RC4().encrypt(
                 h.digest()[0:n_plus_5], object.get_content_bytes()
             )
             # TODO
         if isinstance(object, HexadecimalString):
-            new_content_bytes: bytes = RC4().encrypt(
+            hex_str_new_content_bytes: bytes = RC4().encrypt(
                 h.digest()[0:n_plus_5], object.get_content_bytes()
             )
             # TODO
         if isinstance(object, Stream):
-            new_content_bytes: bytes = RC4().encrypt(
+            stream_new_content_bytes: bytes = RC4().encrypt(
                 h.digest()[0:n_plus_5], object["DecodedBytes"]
             )
-            object[Name("DecodedBytes")] = new_content_bytes
+            object[Name("DecodedBytes")] = stream_new_content_bytes
             object[Name("Bytes")] = zlib.compress(object["DecodedBytes"], 9)
             return object
 
-    def _decrypt_data(self, object: AnyPDFType) -> None:
+        # default
+        return object
+
+    def _decrypt_data(self, object: AnyPDFType) -> AnyPDFType:
         return self._encrypt_data(object)
 
     def _compute_encryption_key(self, password: bytes) -> bytes:
@@ -211,7 +231,6 @@ def _compute_encryption_key(self, password: bytes) -> bytes:
         # MD5 hash and pass the first n bytes of the output as input into a new MD5 hash, where n is the number of
         # bytes of the encryption key as defined by the value of the encryption dictionary’s Length entry.
         if self._revision >= 3:
-            # THIS IS WHERE THE ALGORITHM GOES WRONG
             n: int = int(self._key_length / 8)
             for _ in range(0, 50):
                 h2 = hashlib.md5()
@@ -296,19 +315,22 @@ def _compute_encryption_dictionary_u_value(self, user_password_string: bytes):
         if self._revision == 2:
             # a) Create an encryption key based on the user password string, as described in "Algorithm 2: Computing an
             # encryption key".
-            key: bytes = self._compute_encryption_key(user_password_string)
+            key_rev_2: bytes = self._compute_encryption_key(user_password_string)
 
             # b) Encrypt the 32-byte padding string shown in step (a) of "Algorithm 2: Computing an encryption key", using
             # an RC4 encryption function with the encryption key from the preceding step.
 
             # c) Store the result of step (b) as the value of the U entry in the encryption dictionary.
-            self._u = RC4().encrypt(key, StandardSecurityHandler._pad_or_truncate(None))
+            self._u = RC4().encrypt(
+                key_rev_2, StandardSecurityHandler._pad_or_truncate(None)
+            )
 
             return self._u
+
         if self._revision >= 3:
             # a) Create an encryption key based on the user password string, as described in "Algorithm 2: Computing an
             # encryption key".
-            key: bytes = self._compute_encryption_key(user_password_string)
+            key_rev_3: bytes = self._compute_encryption_key(user_password_string)
 
             # b) Initialize the MD5 hash function and pass the 32-byte padding string shown in step (a) of "Algorithm 2:
             # Computing an encryption key" as input to this function.
@@ -322,15 +344,15 @@ def _compute_encryption_dictionary_u_value(self, user_password_string: bytes):
 
             # d) Encrypt the 16-byte result of the hash, using an RC4 encryption function with the encryption key from step
             # (a).
-            digest = RC4().encrypt(key, digest)
+            digest = RC4().encrypt(key_rev_3, digest)
 
             # e) Do the following 19 times: Take the output from the previous invocation of the RC4 function and pass it as
             # input to a new invocation of the function; use an encryption key generated by taking each byte of the
             # original encryption key obtained in step (a) and performing an XOR (exclusive or) operation between that
             # byte and the single-byte value of the iteration counter (from 1 to 19).
             if self._revision >= 3:
                 for i in range(1, 20):
-                    key2: bytes = bytes([b ^ i for b in key])
+                    key2: bytes = bytes([b ^ i for b in key_rev_3])
                     digest = RC4().encrypt(key2, digest)
 
             # f) Append 16 bytes of arbitrary padding to the output from the final invocation of the RC4 function and store

borb/io/read/font/font_dictionary_transformer.py

@@ -8,7 +8,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Dictionary, Stream
 from borb.pdf.canvas.event.event_listener import EventListener
 from borb.pdf.canvas.font.composite_font.cid_font_type_0 import CIDType0Font

borb/io/read/function/function_dictionary_transformer.py

@@ -10,7 +10,7 @@
 from typing import Any, Optional, Union
 
 from borb.io.filter.stream_decode_util import decode_stream
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Dictionary, Function, Name, Reference, Stream
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/ccitt_fax_image_transformer.py

@@ -11,7 +11,7 @@
 
 from PIL import Image  # type: ignore [import]
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/compressed_jpeg_image_transformer.py

@@ -12,7 +12,7 @@
 from PIL import Image  # type: ignore [import]
 
 from borb.io.filter.stream_decode_util import decode_stream
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Name, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/grayscale_image_transformer.py

@@ -12,7 +12,7 @@
 from PIL import Image  # type: ignore [import]
 
 from borb.io.filter.stream_decode_util import decode_stream
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Reference, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/jbig2_image_transformer.py

@@ -11,7 +11,7 @@
 
 from PIL import Image  # type: ignore [import]
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/jpeg_2000_image_transformer.py

@@ -11,7 +11,7 @@
 
 from PIL import Image  # type: ignore [import]
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/image/jpeg_image_transformer.py

@@ -11,7 +11,7 @@
 
 from PIL import Image  # type: ignore [import]
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Stream, add_base_methods
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/object/array_transformer.py

@@ -8,7 +8,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, List
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/object/dictionary_transformer.py

@@ -8,7 +8,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Dictionary
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/object/stream_transformer.py

@@ -9,7 +9,7 @@
 from typing import Any, Optional, Union
 
 from borb.io.filter.stream_decode_util import decode_stream
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Reference, Stream
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/page/page_dictionary_transformer.py

@@ -9,7 +9,7 @@
 import zlib
 from typing import Any, Dict, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType
 from borb.io.read.types import Decimal as pDecimal
 from borb.io.read.types import Dictionary, List, Name, Stream
@@ -59,7 +59,9 @@ def transform(
             # avoid circular reference
             if k == "Parent":
                 continue
-            v = self.get_root_transformer().transform(v, page_out, context, [])
+            v = self.get_root_transformer().transform(
+                v, page_out, context, event_listeners
+            )
             if v is not None:
                 page_out[k] = v
 
@@ -91,10 +93,13 @@ def transform(
         # create Canvas
         canvas = Canvas().set_parent(page_out)  # type: ignore [attr-defined]
 
-        # create CanvasStreamProcessor
-        CanvasStreamProcessor(page_out, canvas, []).read(
-            io.BytesIO(contents["DecodedBytes"]), event_listeners
-        )
+        # If there are no event listeners, processing the page has no effect
+        # we may as well skip it (cause it is very labour-intensive).
+        if len(event_listeners) > 0:
+            # create CanvasStreamProcessor
+            CanvasStreamProcessor(page_out, canvas, []).read(
+                io.BytesIO(contents["DecodedBytes"]), event_listeners
+            )
 
         # send out EndPageEvent
         for l in event_listeners:

borb/io/read/page/root_dictionary_transformer.py

@@ -9,7 +9,7 @@
 from typing import Any, Dict, List, Optional, Union
 
 from borb.io.read.object.dictionary_transformer import DictionaryTransformer
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Decimal, Dictionary
 from borb.io.read.types import List as pList
 from borb.io.read.types import Name
@@ -34,6 +34,9 @@ def can_be_transformed(
             and object["Type"] == "Catalog"
         )
 
+    def _re_order_pages(self):
+        pass
+
     def transform(
         self,
         object_to_transform: Union[io.BufferedIOBase, io.RawIOBase, AnyPDFType],

borb/io/read/primitive/number_transformer.py

@@ -8,7 +8,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Decimal
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/primitive/string_transformer.py

@@ -8,7 +8,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, HexadecimalString, Name, String
 from borb.pdf.canvas.event.event_listener import EventListener
 

borb/io/read/reference/reference_transformer.py

@@ -10,7 +10,7 @@
 import typing
 from typing import Any, Optional, Union
 
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Reference
 from borb.pdf.canvas.event.event_listener import EventListener
 from borb.pdf.xref.xref import XREF

borb/io/read/reference/xref_transformer.py

@@ -12,7 +12,7 @@
 
 from borb.io.read.encryption.standard_security_handler import StandardSecurityHandler
 from borb.io.read.tokenize.high_level_tokenizer import HighLevelTokenizer
-from borb.io.read.transformer import Transformer, ReadTransformerState
+from borb.io.read.transformer import ReadTransformerState, Transformer
 from borb.io.read.types import AnyPDFType, Dictionary, Name
 from borb.pdf.canvas.event.event_listener import Event, EventListener
 from borb.pdf.document import Document