Tom, inline...
<snip> > > Do you or somebody else on this list (Tom?) have a clue why it may be > > useful to carry out such a check? (EDIT: check of IP address) > > You have lost me here. Suppose I am a server and I want to check that > syslog > only comes from someone I trust so I will configure an identifier in > the server > and want security credentials to authenticate an assertion of that > identity. > The IP address is the identity, and the certificate the security > credential. > > Or the host name is the identity and the certificate the security > credential. > > Or the MAC address is the identity and the certificate the security > credential. > > I do not see a difference (except that some identities are commoner > than others > as Pasi points out). What is common is a big point. I think ipAddress inside certificates is quite uncommon, so this may be a good indication that it doesn't justify a MUST. I have also thought about when this may be used at all. IMHO, this makes only sense if the transport sender uses a proxy or is behind NAT. Using a proxy for syslog senders is extremely uncommon. Being behind NAT is uncommon (usually, syslog is not transmitted to the public Internet). The remaining threat I see is that someone on the same local network poisons ARP with a spoofed IP address and they tries to fool the syslog server in listening to it. While possible, I think this is also quite remote (but remote is not a good argument when it comes to security, I know). What matters more is that this attack will NOT work if the subject's name is checked against the certificate. So what is the extra benefit of authorizing based on IP address? What is the advantage of it? Is that so important that every syslog application implementing MUST support it? I am even in doubt if if justifies a SHOULD. To me it looks MAY would be sufficient, and this is covered by the text. So I think the whole paragraph on ipAddress authentication can simply be removed. As a side-note, authentication based on IP addresses is even problematic. In my experience IP ranges are more likely to change than names, so sticking with names reduces the administrative cost when a change is needed. Rainer > > Tom Petch _______________________________________________ Syslog mailing list [email protected] https://www.ietf.org/mailman/listinfo/syslog
