The code removed is an incomplete implementation of skipping
the Legacy Display Part specified in
https://www.ietf.org/archive/id/draft-autocrypt-lamps-protected-headers-02.html#section-5.2
The code does not fully implement the specification, e.g.
it does not check that there are exactly two parts.
Delta Chat and Thunderbird are not adding this part anyway,
and it is defined as "transitional" in the draft.
This also removes misplaced warning "Ignoring nested protected headers"
that is printed for every incoming Delta Chat message
since commit 5690c48863
which is part of the PR <https://github.com/deltachat/deltachat-core-rust/pull/982>.
It can be used e.g. as a default in the file saving dialog. Also display the original filename in
the message info. For these purposes add Param::Filename in addition to Param::File and use it as an
attachment filename in sent emails.
Message.set_text() and Message.get_text() are modified accordingly
to accept String and return String.
Messages which previously contained None text
are now represented as messages with empty text.
Use Message.set_text("".to_string())
instead of Message.set_text(None).
simplify() is written to process incoming plaintext messages
and extract footers and quotes from them.
Incoming messages contain various quote styles
and simplify() implements heuristics to detects them.
If dehtml() output is processed by simplify(),
simplify() heuristics may erroneously detect
footers and quotes in produced plaintext.
dehtml() should directly detect quotes
instead of converting them to plaintext quotes
for parsing with simplify().
New algorithm improves group consistency
in cases of missing messages,
restored old backups and replies from classic MUAs.
Co-authored-by: Hocuri <hocuri@gmx.de>
Co-authored-by: link2xt <link2xt@testrun.org>
Otherwise sending a message without plaintext part
resets the signature. It is particularly dangerous
in multidevice case, because it's easy to accidentally
reset the signature on your other device with a non-text message.
Moved custom ToSql trait including Send + Sync from lib.rs to sql.rs.
Replaced most params! and paramsv! macro usage with tuples.
Replaced paramsv! and params_iterv! with params_slice!,
because there is no need to construct a vector.
This makes DC compatible with "multipart/signed" messages thus allowing switching to them someday
from the current "multipart/mixed" unencrypted message format.
try_decrypt() is a CPU-bound task.
When called from async function,
it should be wrapped in tokio::task::spawn_blocking().
Using tokio::task::spawn_blocking() is difficult here
because of &mail, &private_keyring and &public_keyring borrows,
so we should at least use tokio::task::block_in_place()
to avoid blocking the executor.
This makes it possible to fuzz test the functions
without exposing the module interface in the deltachat core
interface.
Also ensure that format_flowed will not grow a dependency
on deltachat core types.
If we move the detached signatures validation code out of try_decrypt(), we don't need to convert an
already parsed signed message part to Vec and then parse it back. Also this simplifies the
try_decrypt() semantics and return type. It can't make a good coffee anyway.
Services like Lacre [1] on Disroot and Inbound Encryption on Posteo [2]
offer to encrypt all incoming messages with the provided OpenPGP
public key. Resulting messages are encrypted, but not end-to-end encrypted
and not signed by the sender, therefore should not have a padlock displayed.
However, such encrypted and unsigned message is also not an indication
of an error on ongoing attack, so we shoud not report this as a problem
to the user.
[1] https://lacre.io/
[2] https://posteo.de/en/help/how-do-i-activate-inbound-encryption-with-my-public-pgp-key
This way we don't need a separate code path for signatures validation for unencrypted
messages. Also, now we degrade encryption only if there are no valid signatures, so the code for
upgrading encryption back isn't needed.
Note that if the message is encrypted, we don't check whether it's signed with an attached key
currently, otherwise a massive refactoring of the code is needed because for encrypted messages a
signature is checked and discarded first now.
