Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Jan-Frode Myklebust
On 2009-01-06, Timo Sirainen t...@iki.fi wrote:

 I already asked on IRC whether this was possible, because I was unable
 to find this on the Wiki. It turns out there is a configuration switch
 called `disable_plaintext_auth', but looking at the description this
 only prevents people from using plain-text username/password
 authentication. It does not actually enforce TLS or SSL.
=20
 My question: is there support to enforce TLS when people connect to
 non-SSL ports? If someone comes up with a solution, I'll add it to the
 SSL article on the Wiki.

 Have you enabled non-plaintext authentication? If not, then
 disable_plaintext_auth practically does what you want, because you can't
 authenticate without SSL/TLS.

We have the opposite requirement... Is it possible to enable SSL on the 
POPS/IMAPS-port, without also enabling STARTTLS on the POP/IMAP ports?

We're hosting many mail domains on the same ip-addresses, and offer
mail.$partnername.com as pop/imap server. Now we'd like to also offer
a single name for POPS/IMAPS with a non-per-partner-branded
name mail.securedomain.com on the same set of servers as the non SSL-version
of dovecot is running. This is mostly to avoid needing lots of SSL
certificates.

We're afraid that if we enable STARTTLS, many of our existing clients will
automatically try using SSL towards the wrong name, and get ugly SSL warnings
about certifcate mismatch.


  -jf



Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Giuliano Gavazzi


On T 6 Jan, 2009, at 14:59 , Ed Schouten wrote:


My question: is there support to enforce TLS when people connect to
non-SSL ports? If someone comes up with a solution, I'll add it to the
SSL article on the Wiki.

I'm using Dovecot 1.1.7, installed on a FreeBSD 6.4-STABLE system.


not sure I understand the question correctly, if I do then the answer  
would be you cannot. If the client wants to speak plain it will. I do  
not see why you would want to keep on listening on port 143 if you  
want to enforce SSL, but if you really want to:


   protocol imap {
 listen = 127.0.0.1:143
 ssl_listen = *:993 interface-ip:143
   }

You can of course drop interface-ip:143.

Giuliano


Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Giuliano Gavazzi


On F 9 Jan, 2009, at 13:11 , Giuliano Gavazzi wrote:



On T 6 Jan, 2009, at 14:59 , Ed Schouten wrote:


My question: is there support to enforce TLS when people connect to
non-SSL ports? If someone comes up with a solution, I'll add it to  
the

SSL article on the Wiki.

I'm using Dovecot 1.1.7, installed on a FreeBSD 6.4-STABLE system.


not sure I understand the question correctly, if I do then the  
answer would be you cannot. If the client wants to speak plain it  
will. I do not see why you would want to keep on listening on port  
143 if you


sorry, I wasn't aware that disable_plaintext_auth would suppress the  
AUTH=PLAIN capability list. I would not rely on that though, there  
might be around buggy clients (of which there are in general plenty!)  
that would ignore that...


g


Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Stewart Dean

Dunno if I'm talking about the right thing or if this would help, but...

we have gone over to a single wildcard certficate for everything in the 
*.bard.edu domain (from Digicert)...this costs $495 for a single year, 
less for multiple years.


Then everything coming at a machine of the format: somename.bard.edu 
comes up valid. If the hostname is of the format 
somename1.somename2.bard.edu (or 
somename1.somename2...somenameN.bard.edu) , then you have to 
explicitly list it when submitting the CSR, but you can list up 10 host 
names for the certificate you generate for that machine when submitting 
the CSR


Jan-Frode Myklebust wrote:

On 2009-01-06, Timo Sirainen t...@iki.fi wrote:

We're afraid that if we enable STARTTLS, many of our existing clients will
automatically try using SSL towards the wrong name, and get ugly SSL warnings
about certifcate mismatch.


  -jf
  



--
 Once upon a time, the Internet was a friendly, 
neighbors-helping-neighbors small town, and no one locked their doors. 
Now it's like an apartment in Bed-Stuy: you need three heavy duty 
pick-proof locks, one of those braces that goes from the lock to the 
floor, and bars on the windows  Stewart Dean, Unix System Admin, 
Bard College, New York 12504 sd...@bard.edu voice: 845-758-7475, fax: 
845-758-7035


Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Timo Sirainen

On Jan 9, 2009, at 6:34 AM, Jan-Frode Myklebust wrote:

We have the opposite requirement... Is it possible to enable SSL on  
the

POPS/IMAPS-port, without also enabling STARTTLS on the POP/IMAP ports?


Not currently unless you run two Dovecot installations with different  
configuration files.




Re: [Dovecot] Enforcing TLS

2009-01-09 Thread Jan-Frode Myklebust
On Fri, Jan 09, 2009 at 09:25:46AM -0500, Stewart Dean wrote:
 Dunno if I'm talking about the right thing or if this would help, but...

 we have gone over to a single wildcard certficate for everything in the  
 *.bard.edu domain (from Digicert)...this costs $495 for a single year,  
 less for multiple years.

Yes, I know about these, but that's not what we need. We need lots of
second level domain certs, so a wildcard woun't help.


  -jf


Re: [Dovecot] Enforcing TLS

2009-01-06 Thread Timo Sirainen
On Tue, 2009-01-06 at 14:59 +0100, Ed Schouten wrote:
 I've happily been using Dovecot for a couple of years now, but only a
 couple of days ago I configured it to speak both TLS and SSL for both
 POP3 and IMAP. Ideally I want users to use TLS, but I've enabled SSL,
 because some mailers (at least Apple Mail on OS X Tiger) don't support
 TLS.

BTW. Your TLS/SSL term usage isn't correct. http://wiki.dovecot.org/SSL

 I already asked on IRC whether this was possible, because I was unable
 to find this on the Wiki. It turns out there is a configuration switch
 called `disable_plaintext_auth', but looking at the description this
 only prevents people from using plain-text username/password
 authentication. It does not actually enforce TLS or SSL.
 
 My question: is there support to enforce TLS when people connect to
 non-SSL ports? If someone comes up with a solution, I'll add it to the
 SSL article on the Wiki.

Have you enabled non-plaintext authentication? If not, then
disable_plaintext_auth practically does what you want, because you can't
authenticate without SSL/TLS.



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Re: [Dovecot] Enforcing TLS

2009-01-06 Thread Ed Schouten
* Timo Sirainen t...@iki.fi wrote:
 Have you enabled non-plaintext authentication? If not, then
 disable_plaintext_auth practically does what you want, because you can't
 authenticate without SSL/TLS.

Oh, great. I don't know a lot of IMAP/POP3-internals, but I was unsure
whether `disable_plaintext_auth' still allowed non-secured connections
to take place in my setup, as long as the client used some broken form
of hashing/encoding the password (like base64), which is obviously not
what I want.

Thanks for the information. I'll add it to the Wiki article
SSL/DovecotConfiguration.

-- 
 Ed Schouten e...@80386.nl
 WWW: http://80386.nl/


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