RSVP Cryptographic Authentication -- Updated Message Type Value

RFC 2961 assigned Message Type 12 to Bundle messages while RFC 2747 had already assigned that value to Integrity Response messages. The conflict is resolved by renumbering RFC 2747's messages rather than RFC 2961's because the refresh reduction extension (RFC 2961) entered field deployment before publication and before the conflict was noticed, making it harder to update those deployments.

security

There is no risk of an accidental Integrity handshake succeeding due to the renumbering because both sides of the handshake must use matching numbers. Additionally, the Integrity Response includes a 32-bit cookie that must match the cookie in the Challenge message, and RFC 2961 requires Bundle messages be sent only to Bundle-capable nodes.

security

Two nodes whose Integrity implementations conform to this modification will interoperate using Message Type 12 for Bundle messages and types 25/26 for the Integrity handshake. A non-conformant Integrity implementation will not interoperate with a conformant one, though two non-conformant implementations can still interoperate as before.

security

The Challenge message defined in RFC 2747 shall use Message Type 25, and the Integrity Response message shall use Message Type 26 (25+1), replacing the previously assigned value of 12.

security, registry

No new security considerations are introduced beyond those in RFC 2747 itself and the compatibility issues described in this document.

security