SMPTE ST 430-6-2010 D-Cinema Operations Auditorium Security Messages for Intra-Theater Communications.pdf

1、 Copyright 2010 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved August 18, 2010 Table of Contents Page Foreword . 2 Intellectual Property 2 1 Scope 3 2 Conformance Notation 3 3 Normative References 3 4 Glossary 4 5 Overview (I

2、nformative) 4 6 Message Security, RRP Structure and General Requirements 5 6.1 Message Security: Transport Layer Security (TLS) 5 6.2 Message Structure: Key-Length-Value (KLV) . 5 6.3 General ASM Command Elements 6 6.4 General TLS and RRP Requirements for Auditorium Security Messages 7 7 General Pur

3、pose ASM Commands . 7 7.1 BadRequest Response 8 7.2 GetTime . 9 7.3 GetEventList . 9 7.4 GetEventID . 10 7.5 QuerySPB 11 7.6 GetProjCert . 12 8 Link Encryption ASM Commands . 12 8.1 LEKeyLoad . 13 8.2 LEKeyQueryID . 14 8.3 LEKeyQueryAll . 14 8.4 LEKeyPurgeID . 15 8.5 LEKeyPurgeAll . 16 Annex A Audit

4、orium Security Messages Variable Length Universal Label (UL) Key (Normative) 17 Annex B Bibliography (Informative) . 19 Annex C Explanation of TLS Length Constraints . 20 Page 1 of 20 pages SMPTE ST 430-6:2010 Revision of SMPTE 430-6-2008 SMPTE STANDARD D-Cinema Operations Auditorium Security Messag

5、es for Intra-Theater Communications SMPTE ST 430-6:2010 Page 2 of 20 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in

6、over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely w

7、ith other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices. SMPTE ST 430-6 was prepared by Technology Committee 21DC. Intellectual Property At the time of publicatio

8、n no notice had been received by SMPTE claiming patent rights essential to the implementation of this Standard. However, attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or al

9、l such patent rights. SMPTE ST 430-6:2010 Page 3 of 20 pages 1 Scope The Auditorium Security Message (ASM) specification enables interoperable communication of security-critical information (information necessary to ensure security of D-Cinema content) between devices over an intra-theater exhibitio

10、n network. The specification uses Transport Layer Security (TLS) for authentication and confidentiality, and Key-Length-Value (KLV) coding for message encoding. It defines a protocol, a general purpose request-response message set and a specific message set for link encryption keying. 2 Conformance

11、Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially helpful to the user, but not indispensable, and can be removed, changed, or added edit

12、orially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“

13、 and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibilities, one is recommended as particularly suitable, without mentioning or excludin

14、g others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the documen

15、t. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision will never be defined in the future. A conformant implementation according

16、to this document is one that includes all mandatory provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may“) and need not implement them as described. 3 Normative References The following

17、standards contain provisions which, through reference in this text, constitute provisions of this recommended practice. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this recommended practice are encouraged to

18、 investigate the possibility of applying the most recent edition of the standards indicated below. 336M SMPTE 336M-2007, Data Encoding Protocol Using Key-Length-Value Dcert SMPTE 430-2-2006, D-Cinema Operations Digital Certificate IANA Internet Assigned Numbers Authority. See www.iana.org/assignment

19、s/port-numbers KDM SMPTE 430-1-2006, D-Cinema Operations Key Delivery Message Log SMPTE 430-5-2008, D-Cinema Packaging Security Log Event Class and Constraints TLS “The TLS Protocol, Version 1.0” RFC 2246 See www.ietf.org/rfc/rfc2246.txt TLS-AES “AES Cyphersuites for TLS” RFC 3268 See www.ietf.org/r

20、fc/rfc3268.txt SMPTE ST 430-6:2010 Page 4 of 20 pages 4 Glossary The following acronyms are used in this specification: ASM Auditorium Security Message AES Advanced Encryption Standard BER Basic Encoding Rules (ASN.1) CBC Cipher Block Chaining IMB Image Media Block KLV Key Length Value LDB Link Decr

21、yptor Block LE Link Encryption RRP Request Response Pair RSA Rivest Shamir Adleman public key encryption SHA-1 Secure Hash Algorithm revision 1 SM Security Manager SPB Secure Processing Block TLS Transport Layer Security Uintx Unsigned x bit integer UL Universal Label UTC Coordinated Universal Time

22、UUID Universally Unique Identifier (ISO 11578) 5 Overview (Informative) Exhibition security equipment configurations which employ remote Secure Processing Blocks (SPBs) (i.e., SPBs which are remote from that which contains the Security Manager) require a secure method of communicating with such SPBs

23、. The generic model for this is illustrated in Figure 1. Initiator Responder Figure 1 Auditorium Security Message Model Remote SPB Media Block SPB (End Point) (End Point) Security Manager TLS Link SMPTE ST 430-6:2010 Page 5 of 20 pages The communication security protection mechanism needs to provide

24、 (1) confidentiality, (2) integrity, (3) authentication and (4) prevention of replay. In addition, the mechanism needs to be inexpensive to implement, and simple to support in secure silicon processors. Message descriptions are given in terms of the Initiator and Responder (and this specification ma

25、kes no distinction between messages emanating from the Security Manager vs. the Image Media Block that contains it). As used herein the generic name for a “block” is SPB. 6 Message Security, RRP Structure and General Requirements The implementation of Auditorium Security Messages (ASM) shall be in t

26、he form of a “Request” from the Initiator followed by a “Response” from the Responder (recipient SPB). Each pair of messages is referred to as a Request-Response Pair (RRP). 6.1 Message Security: Transport Layer Security (TLS) Message security shall be provided by communicating ASMs under Transport

27、Layer Security (TLS) (see TLS). During TLS session establishment, the Initiator (which contains the Security Manager) and Responder exchange their X.509 certificates as part of the initial TLS handshake. This exchange shall be supported using D-Cinema compliant certificates as defined in the D-Cinem

28、a Digital Certificate specification DCert. The TLS protocol shall be TLS 1.0 TLS constrained as follows to simplify implementation, facilitate interoperability and ensure predictable processing: 1. 2048-bit RSA using a public exponent value of 65537 shall be the only supported public key algorithm.

29、2. AES-CBC 128-bit shall be the only supported symmetric cipher (see TLS-AES). 3. SHA-1 shall be the only supported hash algorithm. 4. The CipherSuite shall be “TLS_RSA_WITH_AES_128_CBC_SHA” (0x00, 0x2F) (see TLS-AES). 5. The TLSCiphertext.length (TLS section 6.2.3.) shall be less than or equal to 5

30、12 bytes (see Annex C). 6. The Compression Method shall be “null” (no compression). 7. Other than as part of the opening handshake, the ChangeCipherSpec message shall be ignored. 8. When performing TLS handshake mutual authentication, it shall be permissible for the TLS client and server devices to

31、exchange only the respective SPB device leaf certificate. 6.2 Message Structure: Key Length Value (KLV) Request and Response ASMs shall be Key Length Value (KLV) encoded using Fixed Length Pack encoding according to SMPTE 336M-2001 336M. The Fixed Length Universal Label (UL) Key is given in Annex A

32、of this document. As a Fixed Length Pack, each individual item in the Value field comprises only an item value. The KLV Length field shall be a long-form BER value encoded with a fixed length of 4 bytes total. Example: For a KLV packet having a Value field that is 12 bytes in length, the Length fiel

33、d would be encoded as the following 4 bytes, 0x83 0x00 0x00 0x0C (hexadecimal). Each ASM Request-Response Pair (RRP) represents two message types and thus KLV UL “value” registration is required twice for each defined RRP (see Annex A). Note: The recipient of each RRP Request or Response command is

34、implicit by virtue of the TLS socket (which is known at the applications level) that carries the messages. SMPTE ST 430-6:2010 Page 6 of 20 pages 6.3 General ASM Command Elements For each message type, the following shall apply: The command type is denoted within the opening KLV “Key” field (16 byte

35、s). “Length” is a BER-encoded four byte field which describes the length of the message in bytes. “Request_ID” shall be an application level tag for the Request, which shall be echoed by the corresponding Response. A non-zero Request_ID value shall be set by the SM, which should select unique values

36、 (e.g. a sequencing counter) for each TLS connection it manages. (Request_ID generation means is left to implementers and is out of scope of this specification.) Multi-byte integer values shall be sent as big-endian data, meaning most significant byte first. “Event ID” shall be a 32-bit value divide

37、d into two components: o A 13 bit “Event Log” component: The Event Log shall be generated in a sequential (increasing) manner in order to match the Associated log records time sequence. Event Log values shall begin at 0x0000 and end at 0x1FFF. Once 0x1FFF is reached, the next Event Log value shall b

38、e 0x0000. These 13 bits are the 13 least significant bits (LSB) of the 32 bits. o A 19 bit “User Defined Value” component: The definition of these 19 bits is out of the scope of this document and may vary from one implementation to the other. These 19 bits are the 19 most significant bits (MSB) of t

39、he 32 bits. Figure 2 Event ID Structure Note: The Event ID as defined above and as used through this document is different from the Event ID defined in SMPTE 430-4, despite the fact that they share the same name. This Event ID is a Uint32, the Event ID in SMPTE 430-4 is a UUID. General “Response” el

40、ements for each Response command are defined as follows: General Response Elements Element Meaning UInt8 Value RRP successful Request successfully processed 0 RRP failed Responder unable to process Request 1 RRP Invalid Invalid parameter or command structure 2 ResponderBusy Responder too busy to pro

41、cess Request 3 Messages defined in this document may contain batches. A batch is a compound data type that is created from combinations of simple data types. It is usually preceded by a name (e.g., an EventIDBatch is an unordered batch of Event ID values): User Defined Value (19 bits) Event Log (13

42、bits) MSB LSB SMPTE ST 430-6:2010 Page 7 of 20 pages Batch: A compound type comprising multiple individual elements. The elements are unordered, the type is defined, the count of elements is explicit and the size of each element is fixed and explicit. xxxBatch: A batch of zero or more individual ele

43、ments of name “xxx” preceded by a header of 8 bytes. The first 4 bytes of the header define the number of elements to follow and the second 4 bytes define the length of each element, both represented as UInt32. Item Name Type Len UL Meaning Default Number of Items Uint32 4 n/a The number of Items in

44、 the Batch n Item Length Uint32 4 n/a The length of each Item L First component of first instance of xxx . . First of one or more components describing element xxx and having a total length of L . 6.4 General TLS and RRP Requirements for Auditorium Security Messages This section defines implementati

45、on constraints for security assurance, interoperability, RRP contention management and serendipity with other exhibition subsystems which may use network resources shared by these security functions. 1. TLS sessions shall be established by the Initiator following the standard applications level TLS

46、handshake protocol using mutual authentication mode (see TLS). Mutual authentication shall exchange both TLS client (Initiator) and server (Responder) D-Cinema compliant certificates. Note: Certificate utility at each TLS end point is out of scope of this specification; however the purpose of mutual

47、 authentication is to enable the Responder (remote SPB) to receive the Initiators (Image Media Block) certificate to record its thumbprint for logging purposes. 2. RRP protocols shall be synchronous (i.e., each pairing shall be opened and closed before a new RRP is opened between the same two SPBs).

48、 To avoid hang-ups, RRP Responder implementations should be designed to support maximum round-trip Request-to-Response latencies as specified in the message definition sections below. Latency shall be measured from the end of the “Request” message receipt to the start of the “Response” message trans

49、mission. Responders unable to transmit the Response within the specified limit because of a “busy” condition should close that RRP duple by issuance of a BadRequest Response with the general Response element indicating “busy” per the General Response Elements table in Section 6.3. Note: Should the Responder fail to respond (at all) after the specified time limit, the Initiator may consider this a communications failure condition and may, for instance,