Mailpile and the SKS Keyserver attacks

#1

Hello all,

This is just a heads’ up to let you know that I’ve tweaked the Mailpile defaults to avoid the SKS keyserver pool and follow the recommendations described here: https://gist.github.com/rjhansen/67ab921ffb4084c865b3618d6955275f

The relevant code change is https://github.com/mailpile/Mailpile/commit/22e2ff39f9e68bf8baf0651d698303b82ff355b3, and new packages should be available from the nightly Debian repository in a few hours.

I am going to hold off on updating the release branch until the OpenPGP community has had a few more days to discuss this, and y’all have had an opportunity to give me feedback on the change.

#2

Also related: https://github.com/mailpile/Mailpile/pull/2193

#3

An update: Nightly is now back to using the normal SKS Keyservers as its “last resort” place to discover keys (it tries almost all other avenues first, including local e-mail and WKD).

There’s a cap on how large a key it will try to feed GnuPG, keys that are too large just fail. I’ll probably tweak this further over the next few days; there are GnuPG flags for minimizing the amount of data that is imported from a key which might help further mitigate this, with the added benefit that the keychain stays small.

I’m going to have to update the release branch next week once the dust has settled a bit - due to family obligations I won’t manage to get that done any sooner.