[Dovecot] Testing EXTERNAL AUTHENTICATION

[Michael M. Slusarz]

Quoting Stephen Feyrer <steve at toth.org.uk>:

> Hi.
>
> I'm trying to test EXTERNAL AUTHENTICATION in Dovecot.  To do this I  
> first configured Thunderbird and Opera to use my server, neither of  
> them were successful.  As a result I contacted both organisations to  
> enquire if they supported EXTERNAL AUTHENTICATION in their products.  
>  Thunderbird responded and said yes.  However, on closer inspection  
> my contact at Thunderbird identified that support for EXTERNAL  
> AUTHENTICATION was poor at best and then only in SMTP.  From that  
> point on, my contact has been trying to implement support in  
> Thunderbird.

[snip]

> * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID  
> ENABLE AUTH=EXTERNAL] Dovecot ready.
> 01 AUTHENTICATE EXTERNAL
> +
> 01 list "" *
> 01 NO [ALERT] Invalid base64 data in continued response

This is incorrect.  You need this:

C: 01 AUTHENTICATE EXTERNAL
S: +
C:
S: 01 OK

(you are missing the empty response back to the server)

Or, better yet (since SASL-IR is available):

C: 01 AUTHENTICATE EXTERNAL =
S: 01 OK

michael