MBOX-Line: From arnt at gulbrandsen.priv.no  Tue Feb  5 10:36:44 2008
To: imap-protocol@u.washington.edu
From: Arnt Gulbrandsen <arnt@gulbrandsen.priv.no>
Date: Fri Jun  8 12:34:41 2018
Subject: [Imap-protocol] non-ASCII byte sequences in IMAP?
In-Reply-To: <"08Feb5. 091040pst. 58696"@synergy1.parc.xerox.com>
References: <"08Feb3. 133012pst. 58696"@synergy1.parc.xerox.com>
	<3/ZsgW8xag0zKO8asER9/Q.md5@libertango.oryx.com>
	<"08Feb5. 091040pst. 58696"@synergy1.parc.xerox.com>
Message-ID: <rr9fu1gL3aYp0C0eYZ33eQ.md5@libertango.oryx.com>

Bill Janssen writes:
>>  No. LOGIN name password, etc.
>
> Forgive me for being dense, but I don't see how this could happen, 
> according to the protocol spec.

It happens if someone's password includes a non-ASCII letter. IMAP can 
do it, more or less:

a login "name" password {8+}
????

Sensible vendors don't want to tell German customers that anyone whose 
passwords include ? cannot read mail.

> In section 1.2:
>
>    Characters are 7-bit US-ASCII unless otherwise specified.  Other
>    character sets are indicated using a "CHARSET", as described in
>    [MIME-IMT] and defined in [CHARSET].  CHARSETs have important
>    additional semantics in addition to defining character set; refer to
>    these documents for more detail.
>
> And there's no "CHARSET" parameter anywhere in the LOGIN command.

That's right. The better way to do this is to use AUTHENTICATE, which 
has plentiful (and well-defined!) support for non-ASCII (search for 
saslprep to find a starting point). But LOGIN too is used, not too 
seldom.

Arnt

