Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Message Specification
RFC 8551
| Document | Type |
RFC - Proposed Standard
(April 2019; No errata)
Obsoletes RFC 5751
|
|
|---|---|---|---|
| Last updated | 2019-04-30 | ||
| Replaces | draft-schaad-rfc5751-bis | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Russ Housley | ||
| Shepherd write-up | Show (last changed 2017-04-14) | ||
| IESG | IESG state | RFC 8551 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Eric Rescorla | ||
| Send notices to | Russ Housley <housley@vigilsec.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) J. Schaad
Request for Comments: 8551 August Cellars
Obsoletes: 5751 B. Ramsdell
Category: Standards Track Brute Squad Labs, Inc.
ISSN: 2070-1721 S. Turner
sn3rd
April 2019
Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0
Message Specification
Abstract
This document defines Secure/Multipurpose Internet Mail Extensions
(S/MIME) version 4.0. S/MIME provides a consistent way to send and
receive secure MIME data. Digital signatures provide authentication,
message integrity, and non-repudiation with proof of origin.
Encryption provides data confidentiality. Compression can be used to
reduce data size. This document obsoletes RFC 5751.
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 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8551.
Schaad, et al. Standards Track [Page 1]
RFC 8551 S/MIME 4.0 Message Specification April 2019
Copyright Notice
Copyright (c) 2019 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
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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
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.
Schaad, et al. Standards Track [Page 2]
RFC 8551 S/MIME 4.0 Message Specification April 2019
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Specification Overview . . . . . . . . . . . . . . . . . 5
1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 6
1.3. Conventions Used in This Document . . . . . . . . . . . . 7
1.4. Compatibility with Prior Practice of S/MIME . . . . . . . 8
1.5. Changes from S/MIME v3 to S/MIME v3.1 . . . . . . . . . . 9
1.6. Changes from S/MIME v3.1 to S/MIME v3.2 . . . . . . . . . 9
1.7. Changes for S/MIME v4.0 . . . . . . . . . . . . . . . . . 11
2. CMS Options . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1. DigestAlgorithmIdentifier . . . . . . . . . . . . . . . . 12
2.2. SignatureAlgorithmIdentifier . . . . . . . . . . . . . . 12
2.3. KeyEncryptionAlgorithmIdentifier . . . . . . . . . . . . 13
2.4. General Syntax . . . . . . . . . . . . . . . . . . . . . 13
2.4.1. Data Content Type . . . . . . . . . . . . . . . . . . 14
2.4.2. SignedData Content Type . . . . . . . . . . . . . . . 14
2.4.3. EnvelopedData Content Type . . . . . . . . . . . . . 14
2.4.4. AuthEnvelopedData Content Type . . . . . . . . . . . 14
2.4.5. CompressedData Content Type . . . . . . . . . . . . . 14
2.5. Attributes and the SignerInfo Type . . . . . . . . . . . 15
2.5.1. Signing Time Attribute . . . . . . . . . . . . . . . 15
2.5.2. SMIMECapabilities Attribute . . . . . . . . . . . . . 16
2.5.3. Encryption Key Preference Attribute . . . . . . . . . 17
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