RFC 3850 (rfc3850) - Page 2 of 16
Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3
Alternative Format: Original Text Document
RFC 3850 S/MIME 3.1 Certificate Handling July 2004
4.4. PKIX Certificate Extensions. . . . . . . . . . . . . . . 9
5. Security Considerations. . . . . . . . . . . . . . . . . . . . 11
A. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
A.1. Normative References . . . . . . . . . . . . . . . . . . 13
A.2. Informative References . . . . . . . . . . . . . . . . . 14
B. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
C. Editor's Address . . . . . . . . . . . . . . . . . . . . . . . 15
Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 16
1. Overview
S/MIME (Secure/Multipurpose Internet Mail Extensions), described in
[SMIME-MSG], provides a method to send and receive secure MIME
messages. Before using a public key to provide security services,
the S/MIME agent MUST verify that the public key is valid. S/MIME
agents MUST use PKIX certificates to validate public keys as
described in the Internet X.509 Public Key Infrastructure (PKIX)
Certificate and CRL Profile [KEYM]. S/MIME agents MUST meet the
certificate processing requirements documented in this document in
addition to those stated in [KEYM].
This specification is compatible with the Cryptographic Message
Syntax [CMS] in that it uses the data types defined by CMS. It also
inherits all the varieties of architectures for certificate-based key
management supported by CMS.
1.1. Definitions
For the purposes of this document, the following definitions apply.
ASN.1: Abstract Syntax Notation One, as defined in ITU-T X.208
[X.208-88].
Attribute Certificate (AC): An X.509 AC is a separate structure from
a subject's public key X.509 Certificate. A subject may have
multiple X.509 ACs associated with each of its public key X.509
Certificates. Each X.509 AC binds one or more Attributes with one of
the subject's public key X.509 Certificates. The X.509 AC syntax is
defined in [ACAUTH].
Certificate: A type that binds an entity's name to a public key with
a digital signature. This type is defined in the Internet X.509
Public Key Infrastructure (PKIX) Certificate and CRL Profile [KEYM].
This type also contains the distinguished name of the certificate
issuer (the signer), an issuer-specific serial number, the issuer's
signature algorithm identifier, a validity period, and extensions
also defined in that document.
Ramsdell Standards Track