Error 352 when getting Filters

[jhd85]

Describe the bug
I configured a sieve server in SnappyMail to be able to create and manage filter for mail. But opening the Filters section gives me a error:

To Reproduce

1. In snappymail
2. Go to 'Settings'
3. Go to 'Filters'
4. receive 'ERROR 352'.

Expected behavior
Getting a overview of my current filters

Screenshots

Please complete the following information:

• Browser: firefox 123
• IMAP daemon: https://stalw.art
• PHP version: 8.2.15
• SnappyMail Version: 2.35.0
• Mode: nextcloud

Debug/logging information
Place them here (few lines) or as attachments (many lines)

SIEVE[INFO]: > GETSCRIPT "roundcube"\r\n
SIEVE[INFO]: < {335}\r\n
SIEVE[INFO]: < require ["fileinto"];\r\n
# rule:[myrule]\r\n
if allof (header :contains "to" "info@redacted.nu")\r\n
{\r\n
        fileinto "myrule";\r\n
}\r\n
# rule:[paypal]\r\n
if allof (header :contains "to" "paypal@redacted.nu")\r\n
{\r\n
        fileinto "Diensten";\r\n
        stop;\r\n
}\r\n
# rule:[steam]\r\n
if allof (header :contains "to" "steam@redacted.nu")\r\n
{\r\n
        fileinto "Games";\r\n
        stop;\r\n
}\r\n
SIEVE[INFO]: < OK\r\n
SIEVE[INFO]: > LOGOUT\r\n
SIEVE[INFO]: < BYE "Stalwart ManageSieve v0.6.0 bids you farewell."\r\n
SIEVE[ERROR]: MailSo\Net\Exceptions\SocketReadException in /var/www/html/custom_apps/snappymail/app/snappymail/v/2.35.0/app/libraries/MailSo/Net/NetClient.php:275

Additional context

• I also tried the sieve server with roundcube and that works without issue
• Adding filter seems to work (if you just ignore the errors) but can't select capabilities and it still can't get filters afterwards
• I (have to) use short logins for everything (imap, smtp and sieve), so user@domain.com -> user. But can't select this in the admin panel for snappymail for sieve. Only for imap and smtp. But seeing the logging it looks like getting the data from the server works fine.

[the-djmaze]

https://datatracker.ietf.org/doc/html/rfc5804#section-2.3

The server MUST reply with an OK response.

Yours does not. It says: BYE "Stalwart ManageSieve v0.6.0 bids you farewell."

[mdecimus]

The server MUST reply with an OK response.

That is incorrect, you are quoting the example. According to the ManageSieve grammar, both OK, NO and BYE are valid responses for the LOGOUT command:

    response-logout       = response-oknobye
    response-oknobye    = response-ok / response-nobye
    response-nobye        = ("NO" / "BYE") [SP "(" resp-code ")"]
                            [SP string] CRLF
                            ;; The string contains human-readable text
                            ;; encoded as UTF-8.

[m-i-k-e-y]

The RFC states above the example:

   The server MUST reply with an  OK response.  The server MUST ignore commands issued by the client
   after the LOGOUT command.

   The client SHOULD wait for the OK response before closing the
   connection.

So @the-djmaze is correct.

[the-djmaze]

@m-i-k-e-y we both are right.
The problem relies in the RFC.

BYE is important in case of errors, misbehaviour, etc.
https://datatracker.ietf.org/doc/html/rfc5804#section-1.2
In this case LOGOUT is no such thing and the server must respond with OK.
The BYE info is missing in the LOGOUT section.

So based on all info @mdecimus is wrong in this case. And OK is the valid option for normal flow.
Or is their ManageSieve crashing?

[mdecimus]

I agree, there is a "bug" in the RFC. I will have this fixed to use the same response as Pigeonhole since this is what most software was tested against.

However, even if the server is crashing, I think SnappyMail should follow the robustness principle and not fail on unexpected responses for non-critical commands.

[the-djmaze]

However, even if the server is crashing, I think SnappyMail should follow the robustness principle and not fail on unexpected responses for non-critical commands.

True, that's why i made a workaround to not crash on BYE.
Although it is a server hang-up of the connection for whatever reason.

I did make a mistake in IMAP with that, because it does have an untagged BYE followed with a tagged OK.

[mdecimus]

Stalwart has now been updated to return OK instead of BYE. I also submitted an errata to IETF:

The following errata report has been submitted for RFC5804,
"A Protocol for Remotely Managing Sieve Scripts".

--------------------------------------
You may review the report below and at:
https://www.rfc-editor.org/errata/eid7825

--------------------------------------
Type: Editorial

Section: 4

Original Text
-------------
response-logout       = response-oknobye


Corrected Text
--------------
response-logout       = response-ok


Notes
-----
The client sends the LOGOUT command when it is finished with a
  connection and wishes to terminate it.  The server MUST reply with an
  OK response.  The server MUST ignore commands issued by the client
  after the LOGOUT command.

Instructions:
-------------
This erratum is currently posted as "Reported". (If it is spam, it 
will be removed shortly by the RFC Production Center.) Please
use "Reply All" to discuss whether it should be verified or
rejected. When a decision is reached, the verifying party  
will log in to change the status and edit the report, if necessary.

--------------------------------------
RFC5804 (draft-ietf-sieve-managesieve-09)
--------------------------------------
Title               : A Protocol for Remotely Managing Sieve Scripts
Publication Date    : July 2010
Author(s)           : A. Melnikov, Ed., T. Martin
Category            : PROPOSED STANDARD
Source              : Sieve Mail Filtering Language
Area                : Applications
Stream              : IETF
Verifying Party     : IESG

[f0rc3r]

Updated to the newest release 2.35.2 and still get Error 352