Use "--no-auto-check-trustdb" instead of "--trust-model always"

[jamessan]

g:GPGExecutable currently forces --trust-model always in order to avoid the potentially costly trustdb update. This should instead use --no-auto-check-trustdb since that honors the user's trust model but still avoids the db check.

This should happen after any refactoring of how the gpg executable is specified, since g:GPGExecutable currently conflates the executable name along with one of the default arguments.

[blackjackshellac]

This is a better solution to my suggstion to provide a gpg version toggle. separating executable from options is the right approach but wasn't something I wanted to suggest myself :)

[jamessan]

separating executable from options is the right approach but wasn't something I wanted to suggest myself :)

It's something I had been mulling over for awhile, so thanks for prompting me to write it down. :)

[ThomasAH]

--trust-model always (at least originally) isn't about avoiding the costly trustdb update, but to allow using gnupg.vim in a multi-user environment, where a file is encrypted to many people. If one of the recipients edited and saved the file and a key of one of the other recipients wasn't known as valid, this caused an empty .gpg file.

The patch to fix this data-loss was from one of my co-workers.

By now we're setting g:GPGExecutable to a shell script with roughly the following content:

exec gpg --no-options --trust-model always --no-default-keyring \
    --keyring "/some/central/location/keyring.gpg" "$@"

The keyring is centrally maintained by the admins and contains only trusted keys.

So it would be OK for us to remove --trust-model always from gnupg.vim, but for others it might be important to catch the error condition when keys of uncertain validity are used.

[jamessan]

--trust-model always (at least originally) isn't about avoiding the costly trustdb update, but to allow using gnupg.vim in a multi-user environment, where a file is encrypted to many people. If one of the recipients edited and saved the file and a key of one of the other recipients wasn't known as valid, this caused an empty .gpg file.

Thanks for the history, @ThomasAH! If you're easily able to reproduce the scenario, could you see if that problem still exists without --trust-model always? There has been a bit of refactoring in how the encryption happens.

[ThomasAH]

With let g:GPGExecutable="gpg", editing the list of recipients, having recipient keys with unknown validity, and answering No (or just pressing Enter) on the prompt Use this key anyway? (y/N), I get the error message Message could not be encrypted! (Press ENTER) and vim refuses to quit
-> this is good

So my suggestion would be to remove the somewhat insecure default, but provide it (and/or --no-auto-check-trustdb) as an example for possible configurations.

Edit: By the way, I tested this with both, v2.6.1 release and current master 6219a5a (which works for me on the machine I just used for the tests, I still have to investigate the problems with master on the other systems).