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diff --git a/doc/rfc/rfc5159.txt b/doc/rfc/rfc5159.txt new file mode 100644 index 0000000..6f5921e --- /dev/null +++ b/doc/rfc/rfc5159.txt @@ -0,0 +1,451 @@ + + + + + + +Network Working Group L. Dondeti, Ed. +Request for Comments: 5159 QUALCOMM, Inc. +Category: Informational A. Jerichow + Nokia Siemens Networks + March 2008 + + + Session Description Protocol (SDP) Attributes for + Open Mobile Alliance (OMA) Broadcast (BCAST) + Service and Content Protection + +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. + +Abstract + + This document provides descriptions of Session Description Protocol + (SDP) attributes used by the Open Mobile Alliance's Broadcast Service + and Content Protection specification. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 3. New SDP Attributes . . . . . . . . . . . . . . . . . . . . . . 2 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 3 + 5.1. Registration of New SDP Attributes . . . . . . . . . . . . 3 + 5.1.1. Registration of the Attribute + bcastversion:<major>.<minor> . . . . . . . . . . . . . 3 + 5.1.2. Registration of the Attribute stkmstream:<id of + the stkm stream> . . . . . . . . . . . . . . . . . . . 4 + 5.1.3. Registration of the Attribute + SRTPAuthentication:<id for SRTP authentication + algorithm value> . . . . . . . . . . . . . . . . . . . 5 + 5.1.4. Registration of the Attribute SRTPROCTxRate:<ROC + transmission rate> . . . . . . . . . . . . . . . . . . 5 + 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 7.1. Normative References . . . . . . . . . . . . . . . . . . . 6 + 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 + + + + + + + +Dondeti & Jerichow Informational [Page 1] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + +1. Introduction + + The Open Mobile Alliance (OMA) Broadcast (BCAST) group is specifying + service and content protection mechanisms for broadcast services over + wireless networks. As part of that specification, several new SDP + attributes are necessary to allow the broadcast server to signal the + service and content protection parameters to clients. + + Section 8.2.4 of RFC 4566 [1] requires that new SDP attributes are + registered through IANA with name, contact information, and + description (and other similar parameters). A standards track + specification is RECOMMENDED if the new attribute(s) will have + widespread use and interoperability considerations. + + OMA BCAST specifications are expected to be used by broadcast + wireless systems that are based on 3rd Generation Partnership Project + (3GPP) Multimedia Broadcast/Multicast Service (MBMS), 3GPP2 Broadcast + and Multicast Services (BCMCS), and Digital Video Broadcasting - + Handheld (DVB-H). Although this would typically be considered a + "widespread" use, in this case IETF chose to use a non-standards- + track RFC to register the SDP attributes because OMA maintains change + control of the documents that specify the interpretation of the + values in the attributes. + + This document provides descriptions of the SDP attributes used in the + OMA BCAST Service and Content Protection specification [2]. + +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 [3]. + +3. New SDP Attributes + + The following new SDP attributes have been specified: + + o a=bcastversion:<major>.<minor> + + o a=stkmstream:<id of the stkm stream> + + o a=SRTPAuthentication:<id for SRTP authentication algorithm value> + + o a=SRTPROCTxRate:<ROC transmission rate> + + See Section 5 for details on IANA considerations. + + + + + +Dondeti & Jerichow Informational [Page 2] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + +4. Security Considerations + + In addition to the notes in Section 7 of RFC 4566 [1], the following + considerations may be applicable: + + The bcastversion parameter indicates the version of the broadcast + system used for distribution of broadcast content. In case future + versions indicated by this parameter allow for enhanced or additional + security features, the bcastversion parameter, if unprotected, could + be utilized for downgrade attacks. + + The stkmstream parameter provides references to relevant key + management streams so that receivers can map the media streams to key + streams and retrieve the necessary keys to decrypt media. As such, + this parameter could be utilized, if unprotected, for denial-of- + service (DoS) attacks. + +5. IANA Considerations + + Per this document, which follows the guidelines of [5], IANA has + registered a number of SDP attributes. + +5.1. Registration of New SDP Attributes + + IANA has registered a number of OMA BCAST only attributes in the + Session Description Protocol Parameters registry [1]. The + registration data, according to RFC 4566 [1] follows. + + The registration templates below refer to the OMA-TS- + BCAST_SvcCntProtection specification [2]. + +5.1.1. Registration of the Attribute bcastversion:<major>.<minor> + + Contact: Anja Jerichow <anja.jerichow@nsn.com> + + Phone: +49 89 636-45868 + + Attribute name: bcastversion + + Long-form attribute name: BCAST version + + Type of attribute: session level + + This attribute is not dependent on charset. + + + + + + + +Dondeti & Jerichow Informational [Page 3] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + + Purpose: This attribute specifies the OMA BCAST version + "bcastversion" value in the format x.y. + + Specification of attribute values: This attribute has a mandatory + value of the form <major>.<minor>, where <major> and <minor> are + non-negative decimal numbers. The att-value field is of XML data + type decimal. For details, see OMA-TS-BCAST_SvcCntProtection, + Section 10.1.1. + +5.1.2. Registration of the Attribute stkmstream:<id of the stkm stream> + + Contact: Anja Jerichow <anja.jerichow@nsn.com> + + Phone: +49 89 636-45868 + + Attribute name: stkmstream + + Long-form attribute name: Short Term Key Message stream identifier + + Type of attribute: session level or media level + + The attribute can be at session level, in which case it applies to + all media streams, or it can be at media level, in which case it + only applies to the specified media and would overwrite possible + session-level attributes. + + This attribute is not dependent on charset. + + Purpose: The stkmstream attribute specifies the mapping of Short + Term Key Message streams to media streams in the SDP. + + Each session or media stream can have multiple stkmstream + attributes. By comparing the value of this attribute with the + identifier of each STKM stream, the terminal can figure out which + one to listen to and process. We note that this attribute is + optional and hence would not be there for unencrypted media + streams. + + Specification of attribute values: This attribute has a mandatory + value of the form <id of the stkm stream>, a unique non-zero + integer identifying a particular key stream. Numbers are unique + within a particular SDP session, i.e., no global numbering is + required. The att-value field is of XML data type unsignedShort. + For details, see OMA-TS-BCAST_SvcCntProtection, Section 10.1.3. + + + + + + + +Dondeti & Jerichow Informational [Page 4] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + +5.1.3. Registration of the Attribute SRTPAuthentication:<id for SRTP + authentication algorithm value> + + Contact: Anja Jerichow <anja.jerichow@nsn.com> + + Phone: +49 89 636-45868 + + Attribute name: SRTPAuthentication + + Long-form attribute name: SRTP authentication algorithm value + identifier + + Type of attribute: media level + + This attribute is not dependent on charset. + + Purpose: When SRTP is used, the attribute SRTPAuthentication states + which authentication algorithm to use. + + Specification of attribute values: Based on [4], the identifier is a + transform-independent parameter of the cryptographic context for + SRTP in integer format. + + One of the following three integrity transforms registered for the + three modes MUST be used: value "2" for RCCm1, "3" for RCCm2, and + "4" for RCCm3. For details, see OMA-TS-BCAST_SvcCntProtection, + Section 10.4. + +5.1.4. Registration of the Attribute SRTPROCTxRate:<ROC transmission + rate> + + Contact: Anja Jerichow <anja.jerichow@nsn.com> + + Phone: +49 89 636-45868 + + Attribute name: SRTPROCTxRate + + Long-form attribute name: ROC transmission rate + + Type of attribute: media level + + This attribute is not dependent on charset. + + Purpose: When SRTP is used, the attribute SRTPROCTxRate defines the + ROC transmission rate, R. + + + + + + +Dondeti & Jerichow Informational [Page 5] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + + Specification of attribute values: The attribute value MUST be a + decimal integer R between 1 and 65535 inclusive, as specified in + [4]. If the ROC transmission rate is not included in the + negotiation, the default value of 1 SHALL be used. For details, + see OMA-TS-BCAST_SvcCntProtection, Section 10.4. + +6. Acknowledgments + + Many thanks to Hosame Abu-Amara, Francois Ambrosini, David + Castleford, Miguel Garcia, Alfred Hoenes, Charles Lo, and Uwe + Rauschenbach for their help and support. + +7. References + +7.1. Normative References + + [1] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session + Description Protocol", RFC 4566, July 2006. + + [2] Open Mobile Alliance, "Service and Content Protection for Mobile + Broadcast Services", OMA OMA-TS-BCAST_SvcCntProtection-V1_0- + 20071218-D, 2007. + + [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [4] Lehtovirta, V., Naslund, M., and K. Norrman, "Integrity + Transform Carrying Roll-Over Counter for the Secure Real-time + Transport Protocol (SRTP)", RFC 4771, January 2007. + +7.2. Informative References + + [5] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA + Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. + + + + + + + + + + + + + + + + + +Dondeti & Jerichow Informational [Page 6] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + +Authors' Addresses + + Lakshminath Dondeti (editor) + QUALCOMM, Inc. + 5775 Morehouse Dr + San Diego, CA + USA + + Phone: +1 858-845-1267 + EMail: ldondeti@qualcomm.com + + + Anja Jerichow + Nokia Siemens Networks GmbH and Co.KG + Martinstr. 76 + 81541 Munich + Germany + + Phone: +49 89 636-45868 + EMail: anja.jerichow@nsn.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Dondeti & Jerichow Informational [Page 7] + +RFC 5159 OMA BCAST SDP Attributes March 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + + + + + + + + + + + + +Dondeti & Jerichow Informational [Page 8] + |