1593733 - OpenPGP: prefs mailnews.send_plaintext_flowed and mail.server.default.mime_parts_on_demand

Status: NEW

(MailNews Core :: Security: OpenPGP, task)

Description

[Kai Engert [:KaiE:]]

The Enigmail add-on overrides the default values of the following prefs:

// disable flowed text by default
pref("mailnews.send_plaintext_flowed", false);

// disable loading of IMAP parts on demand
pref("mail.server.default.mime_parts_on_demand", false);

Let's track the decision for TB regarding these prefs, and potential consequences of not using the Enigmail preferred values.

Comment 1

[Patrick Brunschwig]

I should probably explain why I change these defaults in Enigmail:

• pref("mailnews.send_plaintext_flowed", false); if we send inline-PGP messages, then flowed text must be disabled as it allows to re-arrange the message text, which will lead to invalid signatures or non-decryptable messages. Being part of Thunderbird, we might be able to disregard the setting for inline-PGP (i.e. if the user creates an inline-PGP message, we ignore format=flowed settings). Alternatively, we might not offer the possibility to create inline-PGP messages.
• pref("mail.server.default.mime_parts_on_demand", false); if Thunderbird does not download the complete message, then PGP/MIME messages can't be decrypted or verified. I believe that this does not happen for S/MIME messages (i.e. that setting is disregarded for S/MIME), and we could just as well do the same for PGP/MIME messages

Comment 2

[Jorg K (CEST = GMT+2)]

Well, mailnews.send_plaintext_flowed", false is a pain in Enigmail. I'm forcing it to true in a user.js and I've never seen a problem with PGP/MIME messages. As Patrick said, only an issue using inline-PGP.

Comment 3

[Kai Engert [:KaiE:]]

Patrick, thanks for the explanations.

Sounds like we should keep both prefs at the TB default values, and dynamically adjust the behavior as necessary, only if necessary.