Skip to main content

Applying Generate Random Extensions And Sustain Extensibility (GREASE) to TLS Extensibility

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc:, The IESG <>,, Sean Turner <>,,,,
Subject: Document Action: 'Applying GREASE to TLS Extensibility' to Informational RFC (draft-ietf-tls-grease-04.txt)

The IESG has approved the following document:
- 'Applying GREASE to TLS Extensibility'
  (draft-ietf-tls-grease-04.txt) as Informational RFC

This document is the product of the Transport Layer Security Working Group.

The IESG contact persons are Benjamin Kaduk and Roman Danyliw.

A URL of this Internet Draft is:

Ballot Text

Technical Summary

The GREASE (Generate Random Extensions And Sustain
Extensibility) mechanism is intended to prevent extensibility
failures in the TLS ecosystem.  This document reserves some
currently unused values for TLS implementations to advertise
at random.  Correctly implemented peers will ignore these
values and interoperate.  Peers that do not tolerate unknown
values will fail to interoperate, revealing the mistake before it
is widespread.

Working Group Summary

The concept is well understood and was reviewed and adopted
by the WG.  But, there's not much to the draft so there was no
controversy (thankfully).

Document Quality

This draft has successfully been implemented in Google Chrome,
and is expected to be adopted by other actors with large deployment
base and interest in sustaining the maintainability of the ecosystem.


Sean Turner is the Document Shepherd.  Benjamin Kaduk is the Responsible AD.

RFC Editor Note