IETF Logo Mail Archive

Re[2]: SNMPv2 security

cyoung@ccmailpc.ctron.com Fri, 28 January 1994 21:23 UTC

Received: from ietf.nri.reston.va.us by IETF.CNRI.Reston.VA.US id aa12415; 28 Jan 94 16:23 EST
Received: from CNRI.RESTON.VA.US by IETF.CNRI.Reston.VA.US id aa12411; 28 Jan 94 16:23 EST
Received: from relay.tis.com by CNRI.Reston.VA.US id aa16794; 28 Jan 94 16:23 EST
Received: by relay.tis.com; id AA00698; Fri, 28 Jan 94 16:01:56 EST
Received: from magellan.tis.com(192.33.112.124) by relay via smap (V1.0mjr) id sma000693; Fri Jan 28 16:01:25 1994
Received: from magellan.tis.com by magellan.TIS.COM id aa16492; 28 Jan 94 15:59 EST
Received: from sol.tis.com by magellan.TIS.COM id aa16488; 28 Jan 94 15:49 EST
Received: from relay.tis.com by tis.com (4.1/SUN-5.64) id AA29032; Fri, 28 Jan 94 15:49:27 EST
Received: by relay.tis.com; id AA00535; Fri, 28 Jan 94 15:49:55 EST
Received: from nic.near.net(192.52.71.4) by relay via smap (V1.0mjr) id sma000525; Fri Jan 28 15:49:44 1994
Received: from ctron.com by nic.near.net id aa23305; 28 Jan 94 15:49 EST
Received: from stealth.ctron.com by ctron.com (4.1/SMI-4.1) id AA28469; Fri, 28 Jan 94 15:49:27 EST
Received: from express.ctron.com by stealth.ctron.com (4.1/SMI-4.1) id AA09789; Fri, 28 Jan 94 15:48:19 EST
Received: from ccmailpc.ctron.com by express.ctron.com (4.1/SMI-4.1) id AA20081; Fri, 28 Jan 94 15:48:18 EST
Received: from ccMail by ccmailpc.ctron.com id AA759800868 Fri, 28 Jan 94 15:47:48 EST
Date: Fri, 28 Jan 1994 15:47:48 -0500
Sender: ietf-archive-request@IETF.CNRI.Reston.VA.US
From: cyoung@ccmailpc.ctron.com
Encoding: 785 Text, 312 HEX
Message-Id: <9400287598.AA759800868@ccmailpc.ctron.com>
To: romanov@nacto.lkg.dec.com, kasten@ftp.com
Cc: snmp@psi.com, snmpv2@magellan.tis.com
Subject: Re[2]: SNMPv2 security 

>Just to show the point, assume that keys are 8-bits long. Let us say
>that you have intercepted the first ten key changes from a manager to
>a specific agent (e.g. the (K1 xor K0) ... (K10 xor K9) exchanges,
>above). The data that you have received are: 0xbf, 0x99, 0x25, 0xc1,
>0x2e, 0xc7, 0x9d, 0xc4, 0x51, and 0x45. What are the keys?

The answer is: fish!  Or in other words, it doesn't matter.

If these are the updates transmitted to the agent and I have copied them
all down then:

        o If I can break the key of the first packet (the one that updated
          agent's key with 0xbf).

        o Then I can XOR the key I have derived with the 10 updates I 
          have received and now I have the key the agent is currently
          using.






-------------------------------------------------------------------------------
Christopher K. Young                                   Cabletron Systems Inc.
cyoung@ctron.com                                       (603) 337-7115
35 Industrial Way P.O. Box 5005                        Rochester, NH 03867-0505

v2.23.0 | Report a Bug | By Email