Support for Adobe's 'aes128-cbc-uncompressed' encryption (see #242)

This commit is contained in:
NoDRM 2023-01-06 14:32:25 +01:00
parent 3c12806f38
commit fb8b003444
2 changed files with 11 additions and 2 deletions

View File

@ -87,3 +87,5 @@ List of changes since the fork of Apprentice Harper's repository:
- Obok: Fix where changing the Calibre UI language to some languages would cause the "duplicate book" setting to reset.
- Fix Python3 bug in stylexml2css.php script, fixes #232.
- PDF: Ignore invalid PDF objids unless the script is running in strict mode. Fixes some PDFs, apparently. Fixes #233.
- Bugfix: EPUBs with remaining content in the encryption.xml after decryption weren't written correctly.
- Support for Adobe's 'aes128-cbc-uncompressed' encryption method (fixes #242).

View File

@ -91,6 +91,7 @@ class Decryptor(object):
self._aes = AES.new(bookkey, AES.MODE_CBC, b'\x00'*16)
self._encryption = etree.fromstring(encryption)
self._encrypted = encrypted = set()
self._encryptedForceNoDecomp = encryptedForceNoDecomp = set()
self._otherData = otherData = set()
self._json_elements_to_remove = json_elements_to_remove = set()
@ -106,6 +107,11 @@ class Decryptor(object):
path = path.encode('utf-8')
encrypted.add(path)
json_elements_to_remove.add(elem.getparent().getparent())
elif (encryption_type_url == "http://ns.adobe.com/adept/xmlenc#aes128-cbc-uncompressed"):
# Adobe uncompressed, for stuff like video files
path = path.encode('utf-8')
encryptedForceNoDecomp.add(path)
json_elements_to_remove.add(elem.getparent().getparent())
else:
path = path.encode('utf-8')
otherData.add(path)
@ -134,13 +140,14 @@ class Decryptor(object):
return decompressed_bytes
def decrypt(self, path, data):
if path.encode('utf-8') in self._encrypted:
if path.encode('utf-8') in self._encrypted or path.encode('utf-8') in self._encryptedForceNoDecomp:
data = self._aes.decrypt(data)[16:]
if type(data[-1]) != int:
place = ord(data[-1])
else:
place = data[-1]
data = data[:-place]
if not path.encode('utf-8') in self._encryptedForceNoDecomp:
data = self.decompress(data)
return data