Revert "Fix for decription key"

This reverts commit bfa40e4a69.

DeDRM_plugin/ineptpdf.py

@@ -427,7 +427,7 @@ def _load_crypto_pycrypto():
             return total
 
         def decrypt(self, data):
-            return _PKCS1_v1_5.new(self._rsa).decrypt(data, b'')
+            return _PKCS1_v1_5.new(self._rsa).decrypt(data, 172)
 
     return (ARC4, RSA, AES)
 
@@ -1901,9 +1901,6 @@ class PDFDocument(object):
         return
 
     def verify_book_key(self, bookkey):
-        if len(bookkey) <= 16:
-            return False
-
         if bookkey[-17] != '\x00' and bookkey[-17] != 0:
             # Byte not null, invalid result
             return False
@@ -1988,6 +1985,7 @@ class PDFDocument(object):
         bookkey = codecs.decode(bookkey.encode('utf-8'),'base64')
         bookkey = rsa.decrypt(bookkey)
 
+        if len(bookkey) > 16:
             if (self.verify_book_key(bookkey)):
                 bookkey = bookkey[-16:]
                 length = 16