Re: iSCSI: Use of SRP (draft -04)

[biran@il.ibm.com]

Steve,

You are correct, we'll change the SRP message sequence similar to telnet (U
--- N,g,s -- A -- B...).

For simultaneous authentication processes (InitAuth, TargetAuth) it seems a
problem of over flexibility. The simpler
and reasonable way would be to negotiate one authentication method
AuthMethod and leave the one way / mutual
authentication decision to the specific method selected. In KERB5 the
client decides it by setting the krb_ap_req mutual
flag, in SRP it's actually mutual.

  Regards,
      Ofer



Ofer Biran
Systems and Software
IBM Research Lab in Haifa
biran@il.ibm.com  972-4-8296253


Steve Senum <ssenum@cisco.com> on 02/28/2001 01:41:01 AM

Please respond to Steve Senum <ssenum@cisco.com>

To:   ietf-ips <ips@ece.cmu.edu>
cc:
Subject:  iSCSI: Use of SRP (draft -04)


Julian:

With respect to use of the SRP protocol for authentication,
I think the current draft is incomplete.  The SRP spec
requires that values for the Prime Modulus value 'N' and the
Generator value 'g' be sent by the authenticating entity
as well as 's' and 'B' (or known through some other method).
Look at RFC 2944 to see how telnet handles this.

Also, if both Initiator and Target choose to authenticate with
SRP, or if InitAuth=KERB5 and TargetAuth=srp, the same key names
will be needed by both sides at the same time, resulting in the
same key name appearing twice in the same text message.  This
will make it difficult for the receiver to know which key names
goes with which authentication process, since there can be two
going on at one time.

Regards,
Steve Senum