NotImplementedError: Haven't implemented Hash Algorithm : 10

[alexlance]

Hi there,

I get this error when I try and decrypt a file:

  File "checker.py", line 95, in <module>
    main()
  File "checker.py", line 74, in main
    dest = process_one_file(bucket, key)
  File "checker.py", line 43, in process_one_file
    tempf = util.decrypt_file(GPG_CONFIG, client_name, tempf)
  File "/root/app/util.py", line 309, in decrypt_file
    key.parse(conf['privatekey'])
  File "/usr/local/lib/python3.7/site-packages/gpglib/structures.py", line 155, in parse
    self.consume(region)
  File "/usr/local/lib/python3.7/site-packages/gpglib/structures.py", line 58, in consume
    self.packet_consumer.consume(self, region)
  File "/usr/local/lib/python3.7/site-packages/gpglib/packet_parser.py", line 47, in consume
    kwargs = self.content_parser.consume(tag, message, kwargs) or {}
  File "/usr/local/lib/python3.7/site-packages/gpglib/content_parsers/delegators.py", line 40, in consume
    return parser.consume(tag, message, tag.body, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/gpglib/content_parsers/keys.py", line 28, in consume
    hasher = Mapped.algorithms.hashes[hash_algorithm]
  File "/usr/local/lib/python3.7/site-packages/gpglib/content_parsers/crypt.py", line 68, in __getitem__
    raise NotImplementedError("Haven't implemented %s : %s" % (self.type, key))
NotImplementedError: Haven't implemented Hash Algorithm : 10

What's hash algo 10? How do we go about implementing it?

I've attached the gpg-key I was using and a snippet of code:

from gpglib.structures import EncryptedMessage, Key

key = Key(passphrase='test passphrase')                                                                                                                                                                                                               
key.parse(k)

key.txt

[delfick]

It appears hash 10 is SHA512

So you'd have to add below this line to use this class

Are you able to make a local copy with that change and see if it works?

[alexlance]

Added a PR , but note, that the PR gets me past the error mentioned in the issue, but now I am stuck on an error like:

gpglib.errors.PGPException: Data was encrypted with RSA key '1325********', which was't found

Have regenerated a key a few times now, it seems convinced that the data was encrypted with a different key. shakes fist at sky

[delfick]

oh no, so if you use your key to generate new information, it works?

[alexlance]

Okay so if I generate a normal RSA key and use the default key length in gpg 2.2.12 (which is 3072 bits) then my script is not able to decrypt any files, I get an error like:

gpglib.errors.PGPException: Data was encrypted with RSA key '6196606***', which was't found

But, if I create a new RSA gpg key with a bit length of 2048, then yes, it is successfully able to decrypt the file!

I feel like it miiight be something to do with this:

gpglib2/gpglib/content_parsers/session_keys.py

Line 12 in 5d6468f

version, key_id, key_algo = region.readlist("""

Like it's not getting the full 3072 bits to identify the key correctly? Is it hard to patch gpglib2 to handle arbitrary key sizes? Or am I barking up the wrong bits...

[delfick]

I made this a long time ago for a very specific purpose. I'm not entirely sure how to fix this and unfortunately I already have too many things happening at the moment to take too deep a look.

A good place to start if you want to figure it out is https://tools.ietf.org/html/rfc4880

Though feel free to ask specific questions about how the code works if you do go down that path :)

[alexlance]

Yep that's totally fair enough, not enough hours in the day at the moment 👍

Btw looks like key length of 4096 also has the same error as above. I'll try and wrap my head around the rfc a bit more.

Cheers for any help, I feel like it's nearly there!

[delfick]

cool. Thanks. I believe in you!