1、 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 of Generic Extra Theater Message (Informative) 5 6 Authenticated and Public (Unencrypted) Information . 6 6.1 MessageId 7 6.2 MessageType . 7 6.3 Annotatio
2、nText . 7 6.4 IssueDate . 8 6.5 Signer . 8 6.6 RequiredExtensions (Optional) 8 6.7 NonCriticalExtensions (Optional) . 8 7 Authenticated and Private (Encrypted) Information 8 7.1 EncryptedKey . 9 7.1.1 EncryptionMethod . 9 7.1.2 KeyInfo 10 7.1.3 CipherData 10 7.1.4 EncryptionProperties . 10 7.1.5 Ref
3、erenceList 10 7.1.6 CarriedKeyName 10 7.2 EncryptedData (Optional) 10 8 Signature Information 11 8.1 XML Embedding . 12 8.2 SignedInfo 13 8.3 SignatureValue . 14 8.4 KeyInfo Certificate Chain . 14 8.5 Object Information 14 Annex A Design Features and Security Goals (Informative) 15 Annex B Bibliogra
4、phy (Informative) 17 Annex C XML Schema for ETM (Normative) 18 Annex D XML Diagram Legend (Informative) . 20 Revision Notes 23 Page 1 of 23 pages SMPTE ST 430-3:2012 Revision of SMPTE 430-3-2008 SMPTE STANDARD D-Cinema Operations Generic Extra-Theater Message Format Copyright 2012 by THE SOCIETY OF
5、MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved August 22, 2012 SMPTE ST 430-3:2012 Page 2 of 23 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally recognized standards developing organization. H
6、eadquartered and incorporated in the United States of America, SMPTE has members in 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 Committee
7、s is open to all with a bona fide interest in their work. SMPTE cooperates closely with 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 Standard 430-3
8、was prepared by Technology Committee 21DC. Intellectual Property At the time of publication 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 t
9、he subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. SMPTE ST 430-3:2012 Page 3 of 23 pages 1 Scope This standard presents a specification for a generic Extra-Theatre Message (ETM) format for use with unidirectional communications channels u
10、sed in security communcations for Digital Cinema (D-Cinema) systems. The ETM specification is a generic XML security wrapper that includes specific fields which can be extended to carry different kinds of information to meet various application-level requirements. (For example, the Key Delivery Mess
11、age (KDM) is a specific instance of this format.) The ETM uses W3C Extensible Markup Language (see XML) to represent the information payload. It provides security using the XML encryption and signature primitives. Note: The brackets convention “” as used herein denotes either a normative or informat
12、ive reference. 2 Conformance 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 re
13、moved, changed, or added editorially 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
14、 “Note:” The keywords “shall“ 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, w
15、ithout mentioning or excluding 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 wit
16、hin the limits of the document. 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 conform
17、ant implementation according 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 Normat
18、ive References The following standards contain provisions that, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encourage
19、d to investigate the possibility of applying the most recent edition of the standards indicated below. D-Cinema Digital Certificate SMPTE 430-2-2006, D-Cinema Operation Digital Certificate FIPS-180-2 “Secure Hash Standard” Version 2. August 1, 2002. FIPS-180-2. See: http:/csrc.nist.gov/publications/
20、fips/fips180-2/fips180-2.pdf SMPTE ST 430-3:2012 Page 4 of 23 pages FIPS-197 “Advanced Encryption Standard (AES)” November 26, 2001. FIPS-197. See: http:/csrc.nist.gov/publications/fips/fips197/fips-197.pdf FIPS-198 “The Keyed-Hash Message Authentication Code (HMAC)” March 6, 2002. File updated Apri
21、l 8, 2002. http:/csrc.nist.gov/publications/fips/fips198/fips-198a.pdf PKCS1 “PKCS #1: RSA Cryptography Specifications Version 2.1” By B. Kaliski. February 2003. RFC 3447 See: http:/www.ietf.org/rfc/rfc3447.txt RFC2253 “Lightweight Directory Access Protocol (v3):UTF-8 String Representation of Distin
22、guished Names” December 1997. See: http:/www.ietf.org/rfc/rfc2253.txt RFC4051 ”Additional XML Security Uniform Resource Identifiers (URIs)” April 2005. See: http:/www.ietf.org/rfc/rfc4051.txt Time UTC, RFC 3339: Date and Time on the Internet: Timestamps. G. Klyne and C. Newman. Informational, July 2
23、002. See: http:/ietf.org/rfc/rfc3339.txt UUID “A Universially Unique Identifier (UUID) URN Namespace” July 2005. See: http:/www.ietf.org/rfc/rfc4122.txt XML “XML Schema Part 1: Structures” World Wide Web Consortium May 2001. See: http:/www.w3.org/TR/2001/REC-xmlschema-1-20010502 XML-Encrypt ”XML Enc
24、ryption Syntax and Processing” World Wide Web Consortium December 2002. See: http:/www.w3.org/TR/2002/REC-xmlenc-core-20021210/ XML-Sign ”XML-Signature Syntax and Processing” World Wide Web Consortium February 2002. See: http:/www.w3.org/TR/2002/REC-xmldsig-core-20020212/ 4 Glossary The following pa
25、ragraphs define the acronyms used in this document. AES: Advanced Encryption Standard secret key algorithm. Defined in FIPS-197. ASN.1: Abstract Syntax Notation 1. Base64: A printable encoding of binary data. See Base64. FIPS: Federal Information Processing Standards of NIST. HMAC-SHA-1: Hash-based
26、Message Authentication Code based on SHA-1. Defined in FIPS-198. IETF: Internet Engineering Task Force standards group. IP: Internet Protocol. An IETF standard. ISO: International Standards Organization. KDM: Key Delivery Message An instance of the ETM. See SMPTE 430-1 LE: Link Encrypter. LD: Link D
27、ecrypter. MD: Media Decrypter. SMPTE ST 430-3:2012 Page 5 of 23 pages NIST: National Institute of Standards and Technologies. OAEP: Optimal Asymmetric Encryption Pattern. See PKCS1. RO: Rights Owner. RSA: Rivest Shamir Adleman public key algorithm. Defined in PKCS1 SE: Security Entity. Any Digital C
28、inema entity that performs cryptography. SHA-1: Secure Hash Algorithm revision 1. Defined in FIPS-180-2. SHA-256: Secure Hash Algoritm. Defined in FIPS-180-2. SM: Security Manager. S/MIME: Secure Multipurpose Internet Mail Extensions. SPB: Secure Processing Block. SSL: Secure Socket Layer protocol.
29、See TLS. TCP: Transmission Control Protocol. IETF standard for reliable bi-directional streams. TLS: Transport Layer Security protocol. See Rescorla. TMS: Theater Management System. X.509: A widely used and supported digital certificate standard. Refer to D-Cinema Digital Certificate XML: Extensible
30、 Markup Language. 5 Overview of Generic Extra Theater Message (Informative) Extra-Theater Messages (ETM) may be used generally between any two D-Cinema Security Entities (SE), however an ETM is particularly appropriate where a unidirectional rather than a bi-directional communications channel is emp
31、loyed. Such channels would be typical of those between a Distributor and an Exhibitor, or between a Studio and a Distributor. The ETM format defined in this document provides a basic message structure having a useful set of known security properties. It is intended that all D-Cinema extra-theatre me
32、ssaging requirements utilize this structure in order to minimize the risk that introduction of new security messages will undermine the integrity of the security system. The following diagram presents an overview of the generic security wrapper. The top-level XML element indicates that this structur
33、e is a D-Cinema Extra-Theatre security Message. It contains three elements (segments) for data: 1) authenticated and public (viewable by anyone who receives the message), 2) authenticated and private (viewable by the intended recipients only), and 3) authentication (signature and trust) information.
34、 SMPTE ST 430-3:2012 Page 6 of 23 pages Figure 1 XML Diagram for Generic Extra Theater Message The AuthenticatedPublic segment includes standard message header information and a place to put required standard extension elements for the particular message type, and a place for proprietary extensions
35、that are not critical to the baseline interoperability standard. The single signer of the ETM is identified in the AuthenticatedPublic segment, and any entity that receives the message is able to read and authenticate the information in the AuthenticatedPublic segment. For ETMs that carry encrypted
36、information in the AuthenticatedPrivate segment, the identity of the recipient of this private information (as specified by the issuer name and serial number of a certificate) appears in a standard field (KeyInfo) of the standard XML EncryptedKey element of the AuthenticatedPrivate segment. To avoid
37、 redundancy, the recipient information is not also carried in the AuthenticatedPublic segment. The AuthenticatedPrivate segment includes zero or more blocks of information encrypted by RSA (called EncryptedKey) and an optional block of information encrypted by AES (called EncryptedData). The use of
38、the EncryptedKey and EncryptedData fields is application-dependent. For example, the KDM message uses the RSA blocks in a special way and does not use the AES block. Other instances of the ETM may use the AuthenticatedPrivate segment to carry data that is hidden from all but the intended recipients.
39、 The data in this segment is encrypted with a fresh random AES key (in the EncryptedData segment), and that AES key is made available to the desired recipient in one or more EncryptedKey elements by encrypting the AES key with the public key of the recipient. The recipient has the matching private k
40、ey, and so can decrypt the RSA block and recover the AES key. The Signature segment includes 1) the value of the signers certificate chain (note that the identity of the signer appears in the AuthenticatedPublic segment), 2) a SignedInfo segment that separately specifies the expected hash of the Aut
41、henticatedPublic and AuthenticatedPrivate parts (this allows any entity that handles this message to detect tampering, even if it is not the intended recipient), and 3) an RSA signature on the SignedInfo element, which thus authenticates the two expected hash values that in turn authenticate the Aut
42、henticatedPublic and AuthenticatedPrivate portions. The Signature segment is not itself authenticated, though it is believed if an attacker made any modifications to the Signature section, then the authentication of the other sections would fail. To facilitate parsing, the ETM is represented with th
43、e UTF-8 character set. All strings intended for human display include a language attribute that is used to select an appropriate character set to display the UTF-8 string contents. All date-time values are expressed in UTC format. The cryptographic mechanisms and structures are from the XML standard
44、s for encryption and digital signatures. 6 Authenticated and Public (Unencrypted) Information The information in this segment of the ETM shall be digitally signed, and trust in the signature can be verified using the certificate chain in the Signature portion. This segment shall not be encrypted, so
45、 any entity that has access to the message can extract this information. The word “public” that appears in the XML label for this portion means that any entity that receives the message can view this portion. SMPTE ST 430-3:2012 Page 7 of 23 pages The formal XML definition is given in Annex C. Figur
46、e 2 is an informative illustration of the appropriate code section from that annex. Figure 2 Authenticated and Public Portion of ETM (Informative) 6.1 MessageId The MessageId field shall be a globally unique identifier for a given ETM that is chosen by the creator of the message. In other words, no
47、two otherwise different messages shall share the same Id. This value is helpful for logging, tracking and indexing ETM messages. It is in the “urn:uuid” format that is also used with the D-Cinema packing list and composition play list standards. 6.2 MessageType The MessageType field identifies the s
48、pecific version and type of the message. It is a URI string that identifies the namespace for the particular ETM instance specification being represented. 6.3 AnnotationText The optional AnnotationText field contains a human-readable description of the message. It is not used in any security-related
49、 process and is only meant as a display hint to human users. Unless the optional xml:lang attribute is specified, the content of the field shall be en. If humans need to troubleshoot a problem related to SMPTE ST 430-3:2012 Page 8 of 23 pages an ETM message, they should be able to refer to the ETM using the AnnotationText and perhaps the IssueDate. Both fields are easier for people to handle than the MessageId. 6.4 IssueDate The IssueDate field indicates the time and date when the mes
