pgpainless-cli fails extracting a certificate from a pubkey with unknown secret key encryption method

[dkg]

Consider an OpenPGP secret key that uses a form of secret key encryption that is unknown to pgpainless.

Even though pgpainless can't use the secret key, i'd expect it to be able to transform it into a valid OpenPGP certificate.

However:

0 dkg@alice:~$ cat test.key 
-----BEGIN PGP PRIVATE KEY BLOCK-----
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=3w/O
-----END PGP PRIVATE KEY BLOCK-----
0 dkg@alice:~$ pgpainless-cli extract-cert < ./test.key 
java.io.EOFException
1 dkg@alice:~$ pgpainless-cli version --extended
PGPainless-SOP 1.6.7
https://codeberg.org/PGPainless/pgpainless/src/branch/master/pgpainless-sop

Implementation of the Stateless OpenPGP Protocol Version 07
https://datatracker.ietf.org/doc/html/draft-dkg-openpgp-stateless-cli-07

Based on pgpainless-core 1.6.7
https://pgpainless.org

Using Bouncy Castle 1.77
https://www.bouncycastle.org/java.html
0 dkg@alice:~$ 

(this example was drawn from a proposed test vector for the hardware-secrets draft, but a similar situation likely applies for any unknown secret key encryption format (maybe even for AEAD for secret keys as described in the crypto-refresh, but i haven't tested it yet)

[vanitasvitae]

Hey!
Thanks for the bug report. It appears that BC 1.77 is currently choking on the test vector. I'll keep this in mind when working on v6 support :)

For the meantime I added a (disabled) test containing the test vector, so we can later make sure BC/PGPainless are handling the key properly.

[vanitasvitae]

For reference: bcgit/bc-java#1719