RFC 3546 (rfc3546) - Page 2 of 29
Transport Layer Security (TLS) Extensions
Alternative Format: Original Text Document
RFC 3546 TLS Extensions June 2003
Table of Contents
1. Introduction ............................................. 2
2. General Extension Mechanisms ............................. 4
2.1. Extended Client Hello ............................... 5
2.2. Extended Server Hello ............................... 5
2.3. Hello Extensions .................................... 6
2.4. Extensions to the handshake protocol ................ 7
3. Specific Extensions ...................................... 8
3.1. Server Name Indication .............................. 8
3.2. Maximum Fragment Length Negotiation ................. 10
3.3. Client Certificate URLs ............................. 11
3.4. Trusted CA Indication ............................... 14
3.5. Truncated HMAC ...................................... 15
3.6. Certificate Status Request........................... 16
4. Error alerts .............................................. 18
5. Procedure for Defining New Extensions...................... 20
6. Security Considerations .................................. 21
6.1. Security of server_name ............................. 21
6.2. Security of max_fragment_length ..................... 21
6.3. Security of client_certificate_url .................. 22
6.4. Security of trusted_ca_keys ......................... 23
6.5. Security of truncated_hmac .......................... 23
6.6. Security of status_request .......................... 24
7. Internationalization Considerations ...................... 24
8. IANA Considerations ...................................... 24
9. Intellectual Property Rights ............................. 26
10. Acknowledgments .......................................... 26
11. Normative References ..................................... 27
12. Informative References ................................... 28
13. Authors' Addresses ....................................... 28
14. Full Copyright Statement ................................. 29
1. Introduction
This document describes extensions that may be used to add
functionality to Transport Layer Security (TLS). It provides both
generic extension mechanisms for the TLS handshake client and server
hellos, and specific extensions using these generic mechanisms.
TLS is now used in an increasing variety of operational environments
- many of which were not envisioned when the original design criteria
for TLS were determined. The extensions introduced in this document
are designed to enable TLS to operate as effectively as possible in
new environments like wireless networks.
Blake-Wilson, et. al. Standards Track