AES-GCM and AES-CCM Authenticated Encryption in Secure RTP (SRTP)
draft-ietf-avtcore-srtp-aes-gcm-06

Network Working Group                                          D. McGrew
Internet Draft                                       Cisco Systems, Inc.
Intended Status: Standards Track                                 K. Igoe
Expires: November 21, 2013                      National Security Agency
                                                            May 20, 2013

    AES-GCM and AES-CCM Authenticated Encryption in Secure RTP (SRTP)   
                   draft-ietf-avtcore-srtp-aes-gcm-06                   

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Igoe and McGrew                 Standards Track                 [Page 1]
Internet Draft         AES-GCM and AES-CCM for SRTP         May 20, 2013

Abstract

   This document defines how AES-GCM and AES-CCM Authenticated
   Encryption with Associated Data algorithms can be used to provide
   confidentiality and data authentication in the SRTP protocol. 
 

Table of Contents

   1. Introduction.....................................................3
   2. Conventions Used In This Document................................3
   3. Overview of the SRTP/SRTCP Security Architecture.................4
   4. Terminology......................................................4
   5. Generic AEAD Processing..........................................5
      5.1. Types of Input Data.........................................5
      5.2. AEAD Invocation Inputs and Outputs..........................5
         5.2.1. Encrypt Mode...........................................5
         5.2.2. Decrypt Mode...........................................6
      5.3. Handling of AEAD Authentication.............................6
   6. Counter Mode Encryption..........................................7
   7. AEAD_AES_128_CCM_12 and AEAD_AES_256_CCM_12......................8
   8. Unneeded SRTP/SRTCP Fields.......................................8
      8.1. SRTP/SRTCP Authentication Field.............................8
      8.2. RTP Padding.................................................9
   9. AES-GCM/CCM processing for SRTP..................................9
      9.1. SRTP IV formation for AES-GCM and AES-CCM...................9
      9.2. Data Types in SRTP Packets..................................9
      9.3. Handling Header Extensions.................................11
      9.4. Prevention of SRTP IV Reuse................................11
   10. AES-GCM/CCM Processing of SRTCP Compound Packets...............12
      10.1. SRTCP IV formation for AES-GCM and AES-CCM................12
      10.2. Data Types in Encrypted SRTCP Compound Packets............12
      10.3. Data Types in Unencrypted SRTCP Compound Packets..........13
      10.4. Prevention of SRTCP IV Reuse..............................14
   11. Constraints on AEAD for SRTP and SRTCP.........................15
      11.1. Generic AEAD Parameter Constraints........................15
      11.2. AES-GCM for SRTP/SRTCP....................................16
      11.3. AES-CCM for SRTP/SRTCP....................................16
   12. Key Derivation Functions.......................................17
   13. Security Considerations........................................17
      13.1. Handling of Security Critical Parameters..................17
      13.2. Size of the Authentication Tag............................17
   14. IANA Considerations............................................18
      14.1. SDES......................................................18