RFC 6506, "Supporting Authentication Trailer for OSPFv3", February 2012
Note: This RFC has been obsoleted by RFC 7166Source of RFC: ospf (rtg)
See Also: RFC 6506 w/ inline errata
Errata ID: 3335
Publication Format(s) : TEXT
Reported By: Manav Bhatia
Date Reported: 2012-09-05
Verifier Name: Stewart Bryant
Date Verified: 2013-01-07
Section 4.5 says:
If the Protocol-Specific Authentication Key (Ks) is L octets long, then Ko is equal to K.
It should say:
If the Protocol-Specific Authentication Key (Ks) is L octets long, then Ko is equal to Ks.
The key K is never used in computing the digest. There is a class of cross protocol attacks that can be prevented if the original key K is appended with a few well known bytes. As a result, the key K is appended with a 2 octet crypto protocol ID to derive a new key Ks. Its this key that must always be used.