1、 IEC TR 62541-2 Edition 2.0 2016-10 TECHNICAL REPORT OPC unified architecture Part 2: Security Model IEC TR 62541-2:2016-10(en) colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2016 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publication m
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10、his publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC TR 62541-2 Edition 2.0 2016-10 TECHNICAL REPORT OPC unified architecture Part 2: Security Model INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 25.040.40; 35.100.01 ISBN 978-2-8322-3641-3 Registered
11、trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside 2 IEC TR 62541-2:2016 IEC 2016 CONTENTS FOREWORD . 4 1 Scope 6 2 Normative references. 6 3 Terms, definitions and abbreviations 8 3.1 Terms a
12、nd definitions 8 3.2 Abbreviations 12 3.3 Conventions for security model figures 12 4 OPC UA security architecture. 12 4.1 OPC UA security environment . 12 4.2 Security objectives 13 4.2.1 Overview 13 4.2.2 Authentication 13 4.2.3 Authorization 13 4.2.4 Confidentiality 14 4.2.5 Integrity . 14 4.2.6
13、Auditability . 14 4.2.7 Availability . 14 4.3 Security threats to OPC UA systems 14 4.3.1 Overview 14 4.3.2 Message flooding . 14 4.3.3 Eavesdropping . 15 4.3.4 Message spoofing 15 4.3.5 Message alteration . 15 4.3.6 Message replay 15 4.3.7 Malformed Messages . 15 4.3.8 Server profiling . 16 4.3.9 S
14、ession hijacking . 16 4.3.10 Rogue Server . 16 4.3.11 Compromising user credentials . 16 4.4 OPC UA relationship to site security 17 4.5 OPC UA security architecture 17 4.6 SecurityPolicies 19 4.7 Security Profiles 20 4.8 User Authorization 20 4.9 User Authentication . 20 4.10 Application Authentica
15、tion . 20 4.11 OPC UA security related Services . 21 4.12 Auditing 21 4.12.1 General 21 4.12.2 Single Client and Server . 22 4.12.3 Aggregating Server 23 4.12.4 Aggregation through a non-auditing Server . 23 4.12.5 Aggregating Server with service distribution 24 5 Security reconciliation 25 5.1 Reco
16、nciliation of threats with OPC UA security mechanisms 25 5.1.1 Overview 25 IEC TR 62541-2:2016 IEC 2016 3 5.1.2 Message flooding . 25 5.1.3 Eavesdropping . 26 5.1.4 Message spoofing 26 5.1.5 Message alteration . 26 5.1.6 Message replay 26 5.1.7 Malformed Messages . 27 5.1.8 Server profiling . 27 5.1
17、.9 Session hijacking . 27 5.1.10 Rogue Server . 27 5.1.11 Compromising user credentials . 27 5.2 Reconciliation of objectives with OPC UA security mechanisms 27 5.2.1 Overview 27 5.2.2 Application Authentication 28 5.2.3 User Authentication 28 5.2.4 Authorization 28 5.2.5 Confidentiality 28 5.2.6 In
18、tegrity . 28 5.2.7 Auditability . 28 5.2.8 Availability . 29 6 Implementation and deployment considerations 29 6.1 Overview. 29 6.2 Appropriate timeouts . 29 6.3 Strict Message processing . 29 6.4 Random number generation 29 6.5 Special and reserved packets 30 6.6 Rate limiting and flow control . 30
19、 6.7 Administrative access 30 6.8 Alarm related guidance 30 6.9 Program access 30 6.10 Audit event management . 31 6.11 Certificate management 31 Bibliography . 36 Figure 1 OPC UA network model 13 Figure 2 OPC UA security architecture . 18 Figure 3 Simple Servers . 22 Figure 4 Aggregating Servers .
20、23 Figure 5 Aggregation with a non-auditing Server . 24 Figure 6 Aggregate Server with service distribution. 25 Figure 7 Manual Certificate handling 32 Figure 8 CA Certificate handling . 33 Figure 9 Certificate handling 34 4 IEC TR 62541-2:2016 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ OP
21、C UNIFIED ARCHITECTURE Part 2: Security Model FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on a
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32、However, a technical committee may propose the publication of a technical report when it has collected data of a different kind from that which is normally published as an International Standard, for example “state of the art“. IEC TR 62541-2, which is a technical report, has been prepared by subcom
33、mittee 65E: Devices and integration in enterprise systems, of IEC technical committee 65: Industrial- process measurement, control and automation. The text of this technical report is based on the following documents: Enquiry draft Report on voting 65E/413/DTR 65E/464/RVC Full information on the vot
34、ing for the approval of this technical report can be found in the report on voting indicated in the above table. IEC TR 62541-2:2016 IEC 2016 5 This second edition cancels and replaces the first edition of IEC TR 62541-2, published in 2010. This second edition includes no technical changes with resp
35、ect to the first edition but a number of clarifications and additional text for completeness. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. Throughout this document and the referenced other parts of the series, certain document conventions are used: Italics are
36、 used to denote a defined term or definition that appears in the “Terms and definition” clause in one of the parts of the series. Italics are also used to denote the name of a service input or output parameter or the name of a structure or element of a structure that are usually defined in tables. T
37、he italicized terms and names are also often written in camel-case (the practice of writing compound words or phrases in which the elements are joined without spaces, with each elements initial letter capitalized within the compound). For example the defined term is AddressSpace instead of Address S
38、pace. This makes it easier to understand that there is a single definition for AddressSpace, not separate definitions for Address and Space. A list of all parts of the IEC 62541 series, published under the general title OPC unified architecture, can be found on the IEC website. The committee has dec
39、ided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amende
40、d. A bilingual version of this publication may be issued at a later date. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this docum
41、ent using a colour printer. 6 IEC TR 62541-2:2016 IEC 2016 OPC UNIFIED ARCHITECTURE Part 2: Security Model 1 Scope This part of IEC 62541, which a Technical Report, describes the OPC unified architecture (OPC UA) security model. It describes the security threats of the physical, hardware, and softwa
42、re environments in which OPC UA is expected to run. It describes how OPC UA relies upon other standards for security. It provides definition of common security terms that are used in this and other parts of the OPC UA specification. It gives an overview of the security features that are specified in
43、 other parts of the OPC UA specification. It references services, mappings, and Profiles that are specified normatively in other parts of this multi-part specification. It provides suggestions or best practice guidelines on implementing security. Any seeming ambiguity between this part of IEC 62541
44、and one of the normative parts of IEC 62541 does not remove or reduce the requirement specified in the normative part. Note that there are many different aspects of security that have to be addressed when developing applications. However since OPC UA specifies a communication protocol, the focus is
45、on securing the data exchanged between applications. This does not mean that an application developer can ignore the other aspects of security like protecting persistent data against tampering. It is important that the developers look into all aspects of security and decide how they can be addressed
46、 in the application. This part of IEC 62541 is directed to readers who will develop OPC UA Client or Server applications or implement the OPC UA services layer. It is also for end users that wish to understand the various security features and functionality provided by OPC UA. It also offers some su
47、ggestions that can be applied when deploying systems. These suggestions are generic in nature since the details would depend on the actual implementation of the OPC UA Applications and the choices made for the site security. It is assumed that the reader is familiar with Web Services and XML/SOAP. I
48、nformation on these technologies can be found in SOAP Part 1: and SOAP Part 2. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated
49、 references, the latest edition of the referenced document (including any amendments) applies. IEC 62351 (all parts), Power systems management and associated information exchange Data and communications security IEC TR 62541-1, OPC unified architecture Part 1: Overview and concepts IEC 62541-4, OPC unified architecture Part 4: Services IEC 62541-5, OPC unified architecture Part 5: Information Model IEC 62541-6, OPC unified architecture Part 6: Mappings IEC 62541-7, OPC unified archite
