Subject: Re: Some Text on Security

From: John Stracke <[email-masked]>
Date: Thu, 01 Apr 1999 16:15:20 +0000

"Larry Osterman (Exchange)" wrote:

> It's my understanding that a
> bunch of the IETF protocols are moving to DIGEST as their must-implement
> authentication mechanism.

When I was at Netscape, Everyone Knew that http-digest was insufficiently
secure.  I don't know details, unfortunately; it was something that everyone
said our security people had said, but I never heard it from our security
people.  Anybody know more?

--
/=============================================================\
|John Stracke    | My opinions are my own | S/MIME & HTML OK  |
[email-masked]|============================================|
|Chief Scientist | NT's lack of reliability is only surpassed |
|eCal Corp.      |  by its lack of scalability. -- John Kirch |
\=============================================================/

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From: Bob Mahoney <[email-masked]>
Date: Thu, 1 Apr 1999 11:19:06 -0500

>people.  Anybody know more?

One snippet from Keith & Patrik's document:

----
2.3 Security

     Although HTTP appears at first glance to be one of the few "mature"
Internet protocols that  can  provide  good  security,  there  are  many
applications  for which neither HTTP's digest authentication nor TLS are
sufficient by themselves.

     Digest authentication requires a secret (e.g.  a  password)  to  be
shared  between  client  and  server.   This  further requires that each
client know the secret to be used with each  server,  but  it  does  not
provide  any  means  of  securely  transmitting such secrets between the
parties.  Shared secrets can work fine for small groups  where  everyone
is physically co-located; they don't work as well for large or dispersed
communities of users.  Further, if the server  is  compromised  a  large
number  of  secrets may be exposed, which is especially dangerous if the
same secret (or password) is used for several applications.

     TLS is  descended  from  SSL,  which  was  originally  designed  to
authenticate servers to clients - not the other way around.  Even though
TLS now provides mutual authentication, a client that needs to  talk  to
multiple  servers  must  still know which credentials to present to each
server before establishing a secure connection to  the  server.   Client
and  server  must  each  use  private keys that are trusted by the other
party - typically because they are signed  by  a  certificate  authority
(CA)  known  to  the  other.  As in the digest authentication case, both
client and server need  ways  to  protect  their  private  keys  against
exposure.
----