Improve key detection for PDFs, too

This commit is contained in:
NoDRM 2021-11-15 13:38:39 +01:00
parent 969fe52e13
commit cc17d9cc59
2 changed files with 67 additions and 5 deletions

View file

@ -463,14 +463,49 @@ class DeDRM(FileTypePlugin):
def PDFDecrypt(self,path_to_ebook):
import calibre_plugins.dedrm.prefs as prefs
import calibre_plugins.dedrm.ineptpdf
import calibre_plugins.dedrm.ineptpdf as ineptpdf
dedrmprefs = prefs.DeDRM_Prefs()
# Attempt to decrypt epub with each encryption key (generated or provided).
print("{0} v{1}: {2} is a PDF ebook".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
book_uuid = None
try:
# Try to figure out which Adobe account this book is licensed for.
book_uuid = ineptpdf.adeptGetUserUUID(path_to_ebook)
except:
pass
if book_uuid is None:
print("{0} v{1}: {2} is a PDF ebook".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
else:
print("{0} v{1}: {2} is a PDF ebook for UUID {3}".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook), book_uuid))
if book_uuid is not None:
# Check if we have a key for that UUID
for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
if not book_uuid.lower() in keyname.lower():
continue
# Found matching key
userkey = codecs.decode(userkeyhex, 'hex')
print("{0} v{1}: Trying UUID-matched encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
of = self.temporary_file(".pdf")
try:
result = ineptpdf.decryptBook(userkey, path_to_ebook, of.name)
of.close()
if result == 0:
print("{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
return of.name
except:
print("{0} v{1}: Exception when decrypting after {2:.1f} seconds - trying other keys".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
traceback.print_exc()
# If we end up here, we didn't find a key with a matching UUID, so lets just try all of them.
# Attempt to decrypt epub with each encryption key (generated or provided).
for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
userkey = codecs.decode(userkeyhex,'hex')
print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
print("{0} v{1}: Trying encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
of = self.temporary_file(".pdf")
# Give the user key, ebook and TemporaryPersistent file to the decryption function.
@ -486,6 +521,7 @@ class DeDRM(FileTypePlugin):
if result == 0:
# Decryption was successful.
# Return the modified PersistentTemporary file to calibre.
print("{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
return of.name
print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))

View file

@ -1992,6 +1992,32 @@ class PDFObjStrmParser(PDFParser):
self.push((pos, token))
return
# Takes a PDF file name as input, and if this is an ADE-protected PDF,
# returns the UUID of the user that's licensed to open this file.
def adeptGetUserUUID(inf):
try:
doc = PDFDocument()
pars = PDFParser(doc, inf)
(docid, param) = doc.encryption
type = literal_name(param['Filter'])
if type != 'EBX_HANDLER':
# No EBX_HANDLER, no idea which user key can decrypt this.
return None
rights = codecs.decode(param.get('ADEPT_LICENSE'), 'base64')
rights = zlib.decompress(rights, -15)
rights = etree.fromstring(rights)
expr = './/{http://ns.adobe.com/adept}user'
user_uuid = ''.join(rights.findtext(expr))
if user_uuid[:9] != "urn:uuid:":
return None
return user_uuid[9:]
except:
return None
###
### My own code, for which there is none else to blame