MIKEY OMA BCAST: Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST 1.0
A new MIKEY payload type that carries mobile broadcast key and parental control messages.
Jerichow, A., Ed. and L. Piron, "Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST 1.0", RFC 5410, DOI 10.17487/RFC5410, January 2009, <https://www.rfc-editor.org/info/rfc5410>.
@misc{rfc5410,
series = {Request for Comments},
number = 5410,
howpublished = {RFC 5410},
publisher = {RFC Editor},
doi = {10.17487/RFC5410},
url = {https://www.rfc-editor.org/info/rfc5410},
author = {A. Jerichow and L. Piron},
title = {{Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST 1.0}},
pagetotal = 7,
year = 2009,
month = jan,
} RFC text
Contents
Network Working Group A. Jerichow, Ed.
Request for Comments: 5410 Nokia Siemens Networks
Obsoletes: 4909 L. Piron
Category: Informational Nagravision S.A.
January 2009
Multimedia Internet KEYing (MIKEY) General Extension Payload
for Open Mobile Alliance BCAST 1.0
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (c) 2009 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 (http://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Abstract
This document specifies a new Multimedia Internet KEYing (MIKEY)
General Extension payload to transport the short-term key message
(STKM) and long-term key message (LTKM) payloads as well as the
management data LTKM reporting message and parental control message
payloads defined in the Open Mobile Alliance's (OMA) Broadcast
(BCAST) group's Service and Content protection specification.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. MIKEY General Extension for OMA BCAST Usage . . . . . . . . . . 3
4. Interoperability Considerations . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
7. Changes since RFC 4909 . . . . . . . . . . . . . . . . . . . . 5
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative References . . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . . 6
1. Introduction
The Multimedia Internet KEYing (MIKEY) protocol specification (RFC
3830 [RFC3830]) defines a General Extension payload to allow possible
extensions to MIKEY without having to allocate a new payload type.
The General Extension payload can be used in any MIKEY message and is
part of the authenticated/signed data part. There is an 8-bit type
field in that payload. The type code assignment is IANA-managed, and
RFC 3830 requires IETF consensus for assignments from the public
range of 0-240.
The Open Mobile Alliance's (OMA) Broadcast (BCAST) group's Service
and Content Protection specification [SPCP] specifies the use of a
short-term key message (STKM), a long-term key message (LTKM), an
LTKM reporting message, and a parental control message that carry
attributes related to Service and Content protection. Note that any
keys associated with the attributes, such as the Parental Control
Pincode if present, are part of the MIKEY KEMAC payload.
This document specifies the use of the General Extension payload of
MIKEY to carry the messages mentioned above, as well as protection of
the credentials using mechanisms supported by MIKEY with
modifications in [RFC3830].
RFC 3830 [RFC3830], the MIKEY General Extension payload defined in
RFC 4563 [RFC4563], and the 3rd Generation Partnership Project
(3GPP)'s Multimedia Broadcast/ Multicast Service (MBMS) document
[3GPP.33.246] specify the transport of MIKEY messages via unicast or
broadcast; the OMA BCAST specifications use either for transport of
MIKEY messages.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
OMA BCAST MIKEY General Extension: We refer to the General Extension
type -- 5 -- as the OMA BCAST MIKEY General Extension.
3. MIKEY General Extension for OMA BCAST Usage
The OMA BCAST Type (Type 5) formats the MIKEY General Extension
payload as follows:
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload ! Type ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! OMA BCAST Data Subtype (variable length) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: OMA BCAST MIKEY General Extension
Next Payload and Length are defined in Section 6.15 of [RFC3830].
Type (8 bits): identifies the type of the General Extension Payload
(see Section 6.15 of [RFC3830]). This document adds a new type. It
specifies the use of Type 5 for OMA BCAST Service and Content
Protection using the Smartcard Profile.
Type | Value | Comments
------------------------------------------------------------------
OMA BCAST | 5 | information on type and identity of messages
Figure 2: Definition of the OMA BCAST MIKEY General Extension Payload
OMA BCAST Data Subtype (variable length): defines a variable length
Data field. This field is formed by subtype-payloads. The contents
of the variable length OMA BCAST Data Subtype field are defined
below.
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Subtype ! Subtype Specific Data (variable length) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: STKM/LTKM/LTKM Reporting/Parental Control Subtype Payload
Subtype: 8 bits. This field indicates the subtype of the OMA
BCAST payload. In this specification, four values are specified:
LTKM (1), STKM (2), LTKM Reporting (3), and Parental Control (4).
Subtype Specific Data: Variable length.
OMA BCAST Data Subtype | Value | Comment
-----------------------------------------------------------
LTKM | 1 | Long Term Key Message
STKM | 2 | Short Term Key Message
LTKM Reporting | 3 | LTKM Reporting Message
Parental Control | 4 | Parental Control Message
Figure 4: Subtype Definitions for OMA BCAST Messages
The contents of the OMA BCAST Data Subtype payload field are defined
in Section 6 of the OMA BCAST Service and Content Protection
specification [SPCP].
4. Interoperability Considerations
This document specifies the use of MIKEY General Extension payload
Type 5 and four subtype values: 1 and 2 for OMA BCAST Service and
Content protection's LTKM and STKM payloads (respectively), 3 for
LTKM Reporting payload, and 4 for Parental Control payload.
Interoperability considerations span several standards bodies, with
OMA BCAST 1.0 enabler compliance being the key aspect; as such, it is
up to the OMA test planning to verify the interoperability and
compliance of OMA BCAST 1.0 implementations. This payload type
assignment does not change MIKEY beyond RFC 3830 [RFC3830] and RFC
4563 [RFC4563].
5. Security Considerations
According to RFC 3830 [RFC3830], the General Extension payload can be
used in any MIKEY message and is part of the authenticated/signed
data part. The parameters proposed to be included in the OMA BCAST
MIKEY General Extension payload (listed in Section 3) need only to be
integrity protected, which is already allowed by the MIKEY
specification. The OMA BCAST MIKEY General Extension payload SHALL
be integrity protected. Furthermore, keys or any parameters that
require confidentiality MUST NOT be included in the General Extension
payload. If keys or other confidential data are to be transported
via the General Extension payload, such data MUST be encrypted and
encapsulated independently. Finally, note that MIKEY already
provides replay protection and that protection also covers the
General Extension payload.
6. IANA Considerations
IANA has allocated an OMA BCAST MIKEY General Extension Type --5--
from the "General Extensions payload name space" for use by OMA BCAST
as requested by RFC 4909 [RFC4909]. Furthermore, IANA has created a
name space for the OMA BCAST payload subtype values defined in
[RFC4909] and has assigned the following subtype values from this
name space: LTKM (1), STKM (2).
IANA has allocated two new subtypes from the OMA BCAST payload
subtype name space.
The subtypes are as follows:
Subtype Name: LTKM Reporting
Value: 3
and
Subtype Name: Parental Control
Value: 4
7. Changes since RFC 4909
OMA BCAST Service and Content Protection specification [SPCP]
contains messages that were created since RFC 4909 was written. This
document only adds the necessary assignments to support these new
messages. No modifications are made on values assigned by RFC 4909
[RFC4909].
8. Acknowledgments
Many thanks to the authors of RFC 4909 [RFC4909] for allowing us to
obsolete their RFC.
9. References
9.1. Normative References
[3GPP.33.246] 3GPP, "3G Security; Security of Multimedia Broadcast/
Multicast Service (MBMS)", 3GPP TS 33.246 6.12.0,
October 2007.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3830] Arkko, J., Carrara, E., Lindholm, F., Naslund, M., and
K. Norrman, "MIKEY: Multimedia Internet KEYing",
RFC 3830, August 2004.
[RFC4563] Carrara, E., Lehtovirta, V., and K. Norrman, "The Key
ID Information Type for the General Extension Payload
in Multimedia Internet KEYing (MIKEY)", RFC 4563,
June 2006.
[SPCP] Open Mobile Alliance, "Service and Content Protection
for Mobile Broadcast Services",
OMA-TS-BCAST_SvcCntProtection-V1_0,
<http://www.openmobilealliance.org>.
9.2. Informative References
[RFC4909] Dondeti, L., Castleford, D., and F. Hartung,
"Multimedia Internet KEYing (MIKEY) General Extension
Payload for Open Mobile Alliance BCAST LTKM/STKM
Transport", RFC 4909, June 2007.
Authors' Addresses
Anja Jerichow (editor)
Nokia Siemens Networks
Martinstr. 76
81541 Munich
Germany
Phone: +49 89 636-45868
EMail: anja.jerichow@nsn.com
Laurent Piron
Nagravision S.A.
Case Postale 134
1033 Cheseaux
Switzerland
Phone: +41 21 732 05 37
EMail: laurent.piron@nagravision.com
AI ELI5
On this page
§1Background and Purpose
MIKEY (Multimedia Internet KEYing, RFC 3830) defines a General Extension payload so that MIKEY can be extended without allocating a new payload type. It can appear in any MIKEY message and is part of the authenticated or signed data. It has an 8-bit type field whose values are managed by IANA.
The Open Mobile Alliance (OMA) Broadcast (BCAST) group's Service and Content Protection specification uses four kinds of message: a short-term key message (STKM), a long-term key message (LTKM), an LTKM reporting message and a parental control message. This document specifies how to carry them in the General Extension payload. Any keys tied to the attributes, such as a Parental Control Pincode, stay in the MIKEY KEMAC payload.
MIKEY is a mail service for secret keys, with a spare envelope for new uses. This memo defines a new use of that envelope for mobile TV messages.
§2The OMA BCAST General Extension Payload
The payload is the General Extension with Type 5, called the OMA BCAST MIKEY General Extension. It has a Next Payload field, an 8-bit Type, a Length, and then a variable-length OMA BCAST Data Subtype field. Next Payload and Length are defined in Section 6.15 of RFC 3830. Type 5 is for OMA BCAST Service and Content Protection using the Smartcard Profile.
The data field begins with an 8-bit Subtype followed by variable-length subtype-specific data. Four subtypes are defined: 1 for LTKM, 2 for STKM, 3 for LTKM Reporting and 4 for Parental Control. What goes inside each is defined in Section 6 of the OMA BCAST specification.
The envelope has a label saying it is for mobile TV, and a smaller label saying which of four letters is inside.
- 1LTKM — Long Term Key Message.
- 2STKM — Short Term Key Message.
- 3LTKM Reporting — LTKM Reporting Message; new in this RFC.
- 4Parental Control — Parental Control Message; new in this RFC.
§3Interoperability
Interoperability spans several standards bodies, with OMA BCAST 1.0 enabler compliance the key aspect, so it is up to OMA test planning to verify compliance of implementations. The RFC says this payload type assignment does not change MIKEY beyond RFC 3830 and RFC 4563.
Whether different phones and servers work together is checked by the group that wrote the mobile TV rules, not by this memo.
§4Security Considerations
The General Extension payload is part of the authenticated or signed data in MIKEY. The OMA BCAST payload only needs integrity protection, and it SHALL be integrity protected. Keys or any parameters needing confidentiality MUST NOT be included in the payload. If confidential data is to be transported this way, it MUST be encrypted and encapsulated independently. MIKEY's replay protection also covers the General Extension payload.
The envelope is sealed so nobody can change it, but secrets must never be written on the outside. Secrets go in their own locked box inside.
§5IANA Assignments and Changes from RFC 4909
IANA allocated type 5 from the General Extensions payload name space for OMA BCAST, as requested by RFC 4909. It also created a name space for OMA BCAST payload subtype values, with LTKM (1) and STKM (2) from RFC 4909, and has now allocated LTKM Reporting (3) and Parental Control (4).
The OMA specification contains messages created after RFC 4909 was written. This document only adds the assignments needed for them and makes no change to values RFC 4909 assigned.
The number registry gets two new entries, 3 and 4. The old entries stay as they were.