eap Mailing List: Proposed Resolution to Issue 261

[Bernard Aboba (aboba]

The text of Issue 261 is given below.  The proposed resolution is as
follows:

In the Section 2.1, change:

"Transient EAP Keys (TEKs)
Session keys which are used to establish a protected channel
between the EAP peer and server during the EAP authentication
exchange. The TEKs are appropriate for use with the ciphersuite
negotiated between EAP peer and server for use in protecting the
EAP conversation. Note that the ciphersuite used to set up the
protected channel between the EAP peer and server during EAP
authentication is unrelated to the ciphersuite used to subsequently
protect data sent between the EAP peer and authenticator. An
example TEK key hierarchy is described in Appendix C."

To:

Transient EAP Session Keys (TESKs)
Session keys which are used to protect EAP framesw sent
between the EAP peer and server during the EAP authentication
exchange. The TESKs are appropriate for use with the ciphersuite
negotiated between EAP peer and server for use in protecting the
EAP conversation. Note that the ciphersuite used to set up the
protected channel between the EAP peer and server during EAP
authentication is unrelated to the ciphersuite used to subsequently
protect data sent between the EAP peer and authenticator. An
example TESK key hierarchy is described in Appendix C."

Change "TEK" to "TESK" and "Transient EAP Key" to "Transient EAP Session
Key" throughout the document.

Change "They remain valid only for the duration of the EAP conversation,
and are lost once the EAP conversation completes."

To:

"EAP methods MUST ensure that TESKs used to protect the EAP
conversation are fresh, so that they are not reused. This implies
that TESKs utilized by EAP methods remain valid only
for the duration of the conversation and are lost once the EAP
conversation completes.

Note that this does not imply a prohibition against caching of
cryptographic state within EAP methods, only that such caching,
if implemented does not result in TESK reuse."