Keying Material Exporters for Transport Layer Security (TLS)
RFC 5705
Document | Type | RFC - Proposed Standard (March 2010; Errata) | |
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Author | Eric Rescorla | ||
Last updated | 2015-10-14 | ||
Replaces | draft-rescorla-tls-extractor | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5705 (Proposed Standard) | |
Action Holders |
(None)
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||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Pasi Eronen | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) E. Rescorla Request for Comments: 5705 RTFM, Inc. Category: Standards Track March 2010 ISSN: 2070-1721 Keying Material Exporters for Transport Layer Security (TLS) Abstract A number of protocols wish to leverage Transport Layer Security (TLS) to perform key establishment but then use some of the keying material for their own purposes. This document describes a general mechanism for allowing that. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/5705. Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow Rescorla Standards Track [Page 1] RFC 5705 TLS Exporters March 2010 modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions Used In This Document . . . . . . . . . . . . . . . 3 3. Binding to Application Contexts . . . . . . . . . . . . . . . . 3 4. Exporter Definition . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 7 1. Introduction Note: The mechanism described in this document was previously known as "TLS Extractors" but was changed to avoid a name conflict with the use of the term "Extractor" in the cryptographic community. A number of protocols wish to leverage Transport Layer Security (TLS) [RFC5246] or Datagram TLS (DTLS) [RFC4347] to perform key establishment but then use some of the keying material for their own purposes. A typical example is DTLS-SRTP [DTLS-SRTP], a key management scheme for the Secure Real-time Transport Protocol (SRTP) that uses DTLS to perform a key exchange and negotiate the SRTP [RFC3711] protection suite and then uses the DTLS master_secret to generate the SRTP keys. These applications imply a need to be able to export keying material (later called Exported Keying Material or EKM) from TLS/DTLS to an application or protocol residing at an upper layer, and to securely agree on the upper-layer context where the keying material will be used. The mechanism for exporting the keying material has the following requirements: o Both client and server need to be able to export the same EKM value. Rescorla Standards Track [Page 2] RFC 5705 TLS Exporters March 2010 o EKM values should be indistinguishable from random data to attackers who don't know the master_secret. o It should be possible to export multiple EKM values from the sameShow full document text