SCRAM-SHA-256 and SCRAM-SHA-256-PLUS Simple Authentication and Security Layer (SASL) Mechanisms
RFC 7677
| Document | Type |
RFC - Proposed Standard
(November 2015; No errata)
Updates RFC 5802
Was draft-hansen-scram-sha256 (individual)
|
|
|---|---|---|---|
| Last updated | 2015-11-02 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Alexey Melnikov | ||
| Shepherd write-up | Show (last changed 2015-07-26) | ||
| IESG | IESG state | RFC 7677 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Stephen Farrell | ||
| Send notices to | (None) | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) T. Hansen
Request for Comments: 7677 AT&T Laboratories
Updates: 5802 November 2015
Category: Standards Track
ISSN: 2070-1721
SCRAM-SHA-256 and SCRAM-SHA-256-PLUS
Simple Authentication and Security Layer (SASL) Mechanisms
Abstract
This document registers the Simple Authentication and Security Layer
(SASL) mechanisms SCRAM-SHA-256 and SCRAM-SHA-256-PLUS, provides
guidance for secure implementation of the original SCRAM-SHA-1-PLUS
mechanism, and updates the SCRAM registration procedures of RFC 5802.
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/rfc7677.
Copyright Notice
Copyright (c) 2015 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.
Hansen Standards Track [Page 1]
RFC 7677 SASL SCRAM-SHA-256/SCRAM-SHA-256-PLUS November 2015
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Key Word Definitions . . . . . . . . . . . . . . . . . . . . 2
3. SCRAM-SHA-256 and SCRAM-SHA-256-PLUS . . . . . . . . . . . . 2
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5.1. Updates to SCRAM-* Registration . . . . . . . . . . . . . 4
5.2. SASL-SCRAM Family Mechanisms Registration Procedure . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
This document registers the SASL mechanisms SCRAM-SHA-256 and SCRAM-
SHA-256-PLUS. SHA-256 has stronger security properties than SHA-1,
and it is expected that SCRAM mechanisms based on it will have
greater predicted longevity than the SCRAM mechanisms based on SHA-1.
The registration form for the SCRAM family of algorithms is also
updated from [RFC5802].
After publication of [RFC5802], it was discovered that Transport
Layer Security (TLS) [RFC5246] does not have the expected properties
for the "tls-unique" channel binding to be secure [RFC7627].
Therefore, this document contains normative text that applies to both
the original SCRAM-SHA-1-PLUS and the newly introduced SCRAM-SHA-
256-PLUS mechanism.
2. Key Word Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. SCRAM-SHA-256 and SCRAM-SHA-256-PLUS
The SCRAM-SHA-256 and SCRAM-SHA-256-PLUS SASL mechanisms are defined
in the same way that SCRAM-SHA-1 and SCRAM-SHA-1-PLUS are defined in
[RFC5802], except that the hash function for HMAC() and H() uses
SHA-256 instead of SHA-1 [RFC6234].
For the SCRAM-SHA-256 and SCRAM-SHA-256-PLUS SASL mechanisms, the
hash iteration-count announced by a server SHOULD be at least 4096.
Hansen Standards Track [Page 2]
RFC 7677 SASL SCRAM-SHA-256/SCRAM-SHA-256-PLUS November 2015
The GSS-API mechanism OID for SCRAM-SHA-256 is 1.3.6.1.5.5.18 (see
Section 5).
This is a simple example of a SCRAM-SHA-256 authentication exchange
when the client doesn't support channel bindings. The username
'user' and password 'pencil' are being used.
C: n,,n=user,r=rOprNGfwEbeRWgbNEkqO
S: r=rOprNGfwEbeRWgbNEkqO%hvYDpWUa2RaTCAfuxFIlj)hNlF$k0,
s=W22ZaJ0SNY7soEsUEjb6gQ==,i=4096
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