Wrong Key expiration for some keys

[DenBond7]

Settings -> Additional Settings -> Select my key -> Key expiration: Key does not expire

My key was generated by https://pgptool.org/

passphrase android

-----BEGIN PGP PRIVATE KEY BLOCK-----
Version: Keybase OpenPGP v2.0.76
Comment: https://keybase.io/crypto
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=J43r
-----END PGP PRIVATE KEY BLOCK-----

The browser app shows the following

But Android(PGPainless) shows the following

Maybe a compatibility issue...

[tomholub]

👍

[tomholub]

Let's have a look at this after #3324

[IvanPizhenko]

Code that extracts key expiration from openpgp-key.ts:

    const { isPrimaryKeyStrong, keyWithoutWeakPackets } = OpenPGPKey.removeWeakKeyPackets(opgpKey);
    let exp: null | Date | number;
    try {
      exp = await keyWithoutWeakPackets.getExpirationTime('encrypt');
    } catch (e) {
      // tslint:disable-next-line: no-null-keyword
      exp = null;
    }

removeWeakKeyPackets() only affects RSA key packets, filters out keys of less than 2048 bits, so should not make any changes to an ECC based key. So such expiration time comes solely from here:

exp = await keyWithoutWeakPackets.getExpirationTime('encrypt');

It's interesting to compare it with what PGPainless does.

@vanitasvitae Can you please explain, how PGPainless determines key expiration time and how this differs from what OpenPGP.js v4 does when we call Key.getExpirationTime('encrypt'). (But obviously there is a bug in our code or OpenPGP.js code because key expiration was set at generation time and PGPainless seems to get it correctly).

[IvanPizhenko]

UPDATE 1: I've imported this key and when I do gpg --list-keys it shows following:

ivan@artline:~/pro/flowcrypt$ gpg --list-keys
gpg: перевірка trustdb
gpg: не знайдено ключів з необмеженою довірою
/home/ivan/.gnupg/pubring.kbx
-----------------------------
pub   nistp384 2022-04-20 [SCA] [діє до: 2024-04-19]
      995FD2D9CBED66324E9EFF50FDF9712E0893B5CA
uid           [невідома] Test <den@test.com>
sub   nistp256 2022-04-20 [SA] [діє до: 2024-04-19]
sub   nistp256 2022-04-20 [SA] [діє до: 2024-04-19]

Please pay attention to this [SA] and [SCA]. This likely means key is for signing and authentication, but not for encryption, while code in the browser extension attempts to get expiation time for encryption key (keyWithoutWeakPackets.getExpirationTime('encrypt')). Keys for encryption are displayed as E. So it likely doesn't find any key for encryption and returns "no expiration".

@tomholub What is the logic behind getting key expiration only for encryption? Should we change it?

[IvanPizhenko]

UPDATE 2:
I've used https://pgptool.org to generate RSA key.
0x66428A68-sec.txt, same passphrase android.
And in this key there is capability for encryption (you can see E):

pub   rsa2048 2022-05-09 [SCEA] [діє до: 2024-05-08]
      469F5C5992C433B21362BBB3319D0E5666428A68
uid           [невідома] Test User <test@example.com>
sub   rsa2048 2022-05-09 [SEA] [діє до: 2024-05-08]
sub   rsa2048 2022-05-09 [SEA] [діє до: 2024-05-08]

I think this is because there is no such thing as "ECC encryption". ECC was always solely for digital signatures. But RSA can be used for the both purposes. Still @tomholub I have a question - what is correct way to deal with keys that are not intended for encryption, how should we show their expiration? Continue to show "does not expire" or attempt to get expiration for "sign" capability and show it, if expiration for "encrypt" capability is N/A?

[vanitasvitae]

The key you shared with the issue indeed only uses ECDSA keys, which are used for signing only.
Elliptic curve encryption keys should use ECDH instead.

I would guess that a key with actual encryption subkeys should also be reported as expiring at some point by OpenPGP.js.

PGPainless tries to determine expiration from subkey binding signatures first, and then falls back to either direct-key signatures, or certification self-signatures over the primary user-ID.

[IvanPizhenko]

@tomholub Any comments here? #4405 (comment)