XOAUTH2 submission - "500 5.5.2 Line too long"

[Teemu Huovila]

On 8.3.2022 18.33, Patrick Nagel wrote:
> Hi,
>
> On Tuesday, 8 March 2022 16:12:48 CET Rosario Esposito wrote:
>> I setup a dovecot submission server, using xoauth2 authentication.
>> My roundcube webmail points to dovecot submission.
>> In roundcube smtp logs, I see:
>>
> [...]
>> [08-Mar-2022 15:47:16 +0100]: <qjonb57c> Send: AUTH XOAUTH2
>> dXNlcj1yZXNwb3NpdAFhdXRoPWJlYXJlci<<<...*very long base64 string*....>>>
>> [08-Mar-2022 15:47:16 +0100]: <qjonb57c> Recv: 500 5.5.2 Line too long
>>
>> Apparently, the problem came out after upgrading from dovecot 2.3.17 to
>> 2.3.18
> Interesting, the changelog (https://github.com/dovecot/core/releases/tag/2.3.18) says:
>
> - submission-login: Authentication does not accept OAUTH2 token (or
>    other very long credentials) because it considers the line to be too long.
>
> But sorry, not much else I can contribute, I'm just a random passerby.
Unfortunately there were some issues with the initial fix to this. There were fixups 
after the release of 2.3.18 to community. 
https://github.com/dovecot/core/commit/667e206a017a48cf623f95f9837e79760be6309b (and 
commits right before)