Cryptographic Message Syntax (CMS)

Abstract

This document describes the Cryptographic Message Syntax (CMS). This syntax is used to digitally sign, digest, authenticate, or encrypt arbitrary message content. Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

UDP Usage Guidelines

“…Many other options for authenticating or encrypting UDP payloads exist. For example, the GSS-API security framework [RFC2743] or Cryptographic Message Syntax (CMS) [RFC5652] could be used to protect UDP payloads. There exist a number of security options for RTP [RFC3550] over UDP, especially to accomplish key-management, see [RFC7201].…”

“…In some applications, a better solution is to protect larger stand-alone objects, such as files or messages, instead of individual UDP payloads. In these situations, CMS [RFC5652], S/MIME [RFC5751] or OpenPGP [RFC4880] could be used. In addition, there are many non-IETF protocols in this area.…”

Trust Anchor Format

“…The taInfo option allows for use of the TrustAnchorInfo structure defined in this document. The TrustAnchorList structure can be protected using the SignedData structure defined in the Cryptographic Message Syntax (CMS) [RFC5652]. The id-ct-trustAnchorList object identifier has been defined to represent TrustAnchorList payloads with CMS structures.…”

Algorithms for Cryptographic Message Syntax (CMS) Encrypted Key Package Content Type

“…EncryptedData [RFC5652] requires that keys be managed by other means; therefore, the only algorithm specified is the content-encryption algorithm. Since the content type is used to carry a cryptographic key and its attributes, an algorithm that is traditionally used to encrypt one key with another is employed.…”

“…Specifically, it includes conventions necessary to implement the following CMS content types: EnvelopedData [RFC5652], EncryptedData [RFC5652], and AuthEnvelopedData [RFC5083].…”