1、BSI Standards Publication BS ISO/IEC 20648:2016 Information technology TLS specification for storage systemsBS ISO/IEC 20648:2016 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO/IEC 20648:2016. The UK participation in its preparation was entrusted to Technica
2、l Committee ICT/-/1, Information systems co-ordination. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The B
3、ritish Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 89890 7 ICS 35.040 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31
4、March 2016. Amendments issued since publication Date Text affectedBS ISO/IEC 20648:2016 Information technology TLS specification for storage systems Technologies de linformation Spcification TLS pour systmes de stockage INTERNATIONAL STANDARD ISO/IEC 20648 Reference number ISO/IEC 20648:2016(E) Firs
5、t edition 2016-03-01 ISO/IEC 2016 BS ISO/IEC 20648:2016ii ISO/IEC 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any me
6、ans, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH
7、-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO/IEC 20648:2016(E)BS ISO/IEC 20648:2016ISO/IEC 20648:2016(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 1 4 Symbols and abbreviated terms . 2 5
8、Overview and concepts 3 5.1 General . 3 5.2 Storage specifications . 3 5.3 Overview of TLS . 4 5.3.1 TLS Background 4 5.3.2 TLS functionality 4 5.3.3 Summary of cipher suites. 4 5.3.4 X.509 digital certificates 5 6 Requirements 5 6.1 TLS protocol requirements 5 6.2 Cipher suites . 6 6.2.1 Required c
9、ipher suites for interoperability 6 6.2.2 Recommended cipher suites for enhanced security . 6 6.3 Digital certificates. 7 7 Guidance for the implementation and use of TLS in data storage 7 7.1 Digital certificates. 7 7.1.1 Certificate model 7 7.1.2 Chain of trust . 8 7.1.3 Certificate lifecycle . 8
10、7.1.4 Revocation . 8 7.2 Security awareness 8 7.3 Cipher suites . 9 7.4 Using TLS with HTTP . 9 7.5 Use of pre-shared keys . 9 Bibliography .11 ISO/IEC 2016 All rights reserved iii Contents PageBS ISO/IEC 20648:2016ISO/IEC 20648:2016(E) Foreword ISO (the International Organization for Standardizatio
11、n) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to de
12、al with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and I
13、EC have established a joint technical committee, ISO/IEC JTC 1. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of document should
14、 be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible
15、for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for th
16、e convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL:
17、Foreword Supplementary information. ISO/IEC 20648 was prepared by the Storage Networking Industry Association (SNIA) as TLS Specification for Storage Systems, Version 1.0.1 and was adopted, under the PAS procedure, by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with
18、its approval by the national bodies of ISO and IEC. The content of ISO/IEC 20648 and SNIA TLS Specification for Storage Systems Version 1.0.1 is identical.iv ISO/IEC 2016 All rights reservedBS ISO/IEC 20648:2016ISO/IEC 20648:2016(E) Introduction Within Information and Communications Technology (CT),
19、 one of the best defenses against telecommunications attacks is to deploy security services implemented with mechanisms specified in standards that are thoroughly vetted in the public domain and rigorously tested by third party laboratories, by vendors, and by users of commercial off-the-shelf produ
20、cts. Three services that most often address network user security requirements are confidentiality, message integrity and authentication. The Internet Engineering Task Force (IETF) with its Transport Layer Security (TLS) has a standard that is able to prevent tampering, message forgery, and eavesdro
21、pping by encrypting data units, or segments, from one end of the transport layer to the other. In addition, TLS is application protocol independent, which means higher-level protocols like HTTP can layer on top of the TLS protocol transparently. Additional details beyond the basic TLS protocol speci
22、fication are necessary to ensure both security and interoperability. This specification provides that detail in the form of specific requirements and guidance for using Transport Layer Security (TLS) in conjunction with storage systems. ISO/IEC 2016 All rights reserved vBS ISO/IEC 20648:2016BS ISO/I
23、EC 20648:2016Information technology TLS specification for storage systems 1 Scope This specification details the requirements for use of the Transport Layer Security (TLS) protocol in conjunction with data storage technologies. The requirements set out in this specification are intended to facilitat
24、e secure interoperability of storage clients and servers as well as non-storage technologies that may have similar interoperability needs. This specification is relevant to anyone involved in owning, operating or using data storage devices. This includes senior managers, acquirers of storage product
25、 and service, and other non-technical managers or users, in addition to managers and administrators who have specific responsibilities for information security and/or storage security, storage operation, or who are responsible for an organizations overall security program and security policy develop
26、ment. It is also relevant to anyone involved in the planning, design and implementation of the architectural aspects of storage security. 2 Normative references The following referenced documents, in whole or in part, are normatively referenced in this document and are indispensable for its applicat
27、ion. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 27000, Information technology Security techniques Information security management systems Overview and vocabulary IETF RFC 5280
28、, Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile, IETF, 2008 IETF RFC 5246, The Transport Layer Security (TLS) Protocol Version 1.2, IETF, 2008 IETF RFC 5746, Transport Layer Security (TLS) Renegotiation Indication Extension, IETF, 2010 3 Terms and
29、 definitions For the purposes of this document, the terms and definitions given in ISO/IEC 27000 and the following apply. 3.1 cipher suite named combination of authentication, encryption, and message authentication code algorithms used to negotiate the security settings for a network connection Note
30、 1 to entry: Cipher suites are typically used with the Transport Layer Security (TLS) and the Secure Sockets Layer (SSL) network protocols. 3.2 digital certificate data structure signed with a digital signature that is based on a public key and which asserts that the key belongs to a subject identif
31、ied in the structure INTERNATIONAL ST ANDARD ISO/IEC 20648:2016(E) ISO/IEC 2016 All rights reserved 1BS ISO/IEC 20648:2016ISO/IEC 20648:2016(E) 3.3 perfect forward secrecy security condition in which a leaving entity cannot obtain any subsequent shared secret keys SOURCE: ISO/IEC 11770-5:2011, 3.24
32、3.4 proxy intermediary that acts as both a server and a client for the purpose of making requests on behalf of other clients 3.5 self-signed certificate digital certificate (3.2) that is signed by the same entity whose identity it certifies Note 1 to entry: A self-signed certificate is one signed wi
33、th its own private key. 3.6 security strength a number associated with the amount of work (i.e. the number of operations) that is required to break a cryptographic algorithm or system Note 1 to entry: Security strength is specified in bits, and is a specific value from the set 80, 112, 128, 192, 256
34、. A security strength of b bits means that of the order of 2 boperations are required to break the system. SOURCE: ISO/IEC 9797-2:2011, 3.14 4 Symbols and abbreviated terms 3DES Triple Data Encryption Standard AED Authenticated Encryption with Additional Data AES Advanced Encryption Standard CA Cert
35、ificate Authority CBC Cipher Block Chaining CDMI Cloud Data Management Interface CRL Certificate Revocation List CRLDP CRL Distribution Point DER Distinguished Encoding Rules DHE Ephemeral Diffie-Hellman DSA Digital Signature Algorithm ECDHE Elliptic Curve Ephemeral DiffieHellman ECDSA Elliptic Curv
36、e Digital Signature Algorithm EDE Encryption-Decryption-Encryption GCM Galois/Counter Mode HMAC Hash-based Message Authentication Code HTTP Hypertext Transfer Protocol HTTPS Hypertext Transfer Protocol Secure ICT Information and Communications Technology IETF Internet Engineering Task Force IP Inter
37、net Protocol MAC Message Authentication Code MD5 Message Digest 5 OCSP Online Certificate Status Protocol2 ISO/IEC 2016 All rights reservedBS ISO/IEC 20648:2016ISO/IEC 20648:2016(E) PEM Privacy Enhanced Mail PKCS Public-Key Cryptography Standards PKI Public Key Infrastructure PSK Pre-Shared Key RFC
38、Request For Comment RSA Rivest, Shamir, and Adelman algorithm SHA Secure Hash Algorithm SMI-S Storage Management Initiative Specification SNIA Storage Networking Industry Association SSL Secure Socket Layer TCP Transmission Control Protocol TLS Transport Layer Security 5 Overview and concepts 5.1 Ge
39、neral Data storage systems and infrastructure increasingly use technologies such as protocols over TCP/IP to manage the systems and data as well as to access the data. In many situations, the historical reliance on isolated connectivity, specialized technologies, and the physical security of data ce
40、nters are not sufficient to protect data, especially when the data is considered sensitive and/or high value. Thus, there is a need to include security at the transport layer and at the same time, ensure interoperability. The Transport Layer Security (TLS) and its predecessor, the Security Socket La
41、yer (SSL), have been used successfully to protect a wide range of communications over TCP/IP. Recognizing this fact, the storage industry has mandated the use of TLS/SSL in conjunction with the Hypertext Transfer Protocol (HTTP) for multiple specifications (see 5.2). Unfortunately, these storage spe
42、cifications tend to be lengthy and complex, resulting in long development cycles that dont allow for rapid requirements changes due to security vulnerabilities or new attacks. The objectives for this specification are to: Specify the TLS elements necessary to secure storage management and data acces
43、s Facilitate timely updates and enhancements to the security for the storage specifications Ensure storage clients and systems can interoperate securely Support non-storage technologies that may have similar TLS interoperability needs 5.2 Storage specifications As a starting point, the TLS requireme
44、nts were extracted from the following specification: ISO/IEC 17826:2012, Information technology Cloud Data Management Interface (CDMI) Storage Networking Industry Association (SNIA), Storage Management Initiative Specification (SMI-S), Version 1.6.1 These requirements were then harmonized, eliminati
45、ng minor differences. The resulting requirements (see clause 6) have been updated to reflect the current state of TLS and attack mitigation strategies. ISO/IEC 2016 All rights reserved 3BS ISO/IEC 20648:2016ISO/IEC 20648:2016(E) 5.3 Overview of TLS 5.3.1 TLS Background TLS is a protocol that provide
46、s communications security over networks. It allows client/server applications to communicate in a way that is designed to prevent eavesdropping, tampering, or message forgery. TLS is layered on top of some reliable transport protocol (e.g., TCP), and it is used for encapsulation of various higher-le
47、vel protocols (e.g., HTTP). TLS version 1.2 of the protocol is specified in IETF RFC 5246. Earlier, and less secure, versions of TLS are also specified and in use; TLS versions 1.0 is specified in IETF RFC 2246 and TLS versions 1.1 is specified in IETF RFC 4346. The predecessor to TLS, The Secure So
48、ckets Layer (SSL), and in particular, version 3.0 is also in use, but also considered less secure; SSL 3.0 is documented in the historical IETF RFC 6101, The Secure Sockets Layer (SSL) Protocol Version 3.0. 5.3.2 TLS functionality TLS provides endpoint authentication and communications privacy over
49、the network using cryptography. Typically, only the server is authenticated (i.e., its identity is ensured) while the client remains unauthenticated; this means that the end user (whether an individual or an application) has a measure of assurance with whom they are communicating. Mutual authentication (the identities of both endpoints are verified) requires, with few exceptions, the deployment of digital certificates on the client. TLS involves three basic phases: a) Pee
