http://www.rfc-editor.org/rfc/rfc6476.txt
RFC 6476: Using Message Authentication Code (MAC) Encryption in the Cryptographic Message Syntax (CMS), P. Gutmann2012-01-01T23:00:00-00:00This document specifies the conventions for using Message Authentication Code (MAC) encryption with the Cryptographic Message Syntax (CMS) authenticated-enveloped-data content type. This mirrors the use of a MAC combined with an encryption algorithm that's already employed in IPsec, Secure Socket Layer / Transport Layer Security (SSL/TLS) and Secure SHell (SSH), which is widely supported in existing crypto libraries and hardware and has been extensively analysed by the crypto community. [STANDARDS-TRACK]