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Re: Forcing TLS encryption

On Fri, 28 Dec 2012, Wiebe Cazemier wrote:
> I understand that, but this way, even when you're forcing TLS, users can 
> still expose their passwords if their computers are mal-configured. 
> SMTP, IMAP, FTP, etc don't allow this, because they reject the 
> connection if LOGINNAME is given before STARTTLS.

That is not true of SMTP's AUTH PLAIN, IMAP's AUTHENTICATE PLAIN, or 
IMAP's LOGIN.  The PLAIN SASL mechanism and IMAP's LOGIN command both send 
the username and password without waiting for a response from the 
server**.


> It's kind of a security issue. Is it because in LDAP, username and 
> password are given as one command, and the server doesn't have the 
> chance to abort at that point? If so, then I guess it's unavoidable.

Correct.


Philip Guenther

** Well, to be completely accurate, IMAP AUTHENTICATE requires a server 
response if the server doesn't support the SASL-IR capability