Transcription
Citrix Presentation ServerSecurity Standards and Deployment ScenariosIncluding Common Criteria InformationCitrix Presentation Server 4.5
Copyright and Trademark NoticeInformation in this document is subject to change without notice. Companies, names, and data used in examples herein arefictitious unless otherwise noted. Other than printing one copy for personal use, no part of this document may be reproduced ortransmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission ofCitrix Systems, Inc.Copyright 2007 Citrix Systems, Inc. All rights reserved.Citrix, ICA (Independent Computing Architecture), and Program Neighborhood are registered trademarks, and CitrixPresentation Server, Citrix Password Manager, Citrix Developer Network, and SpeedScreen are trademarks of Citrix Systems,Inc. in the United States and other countries.RSA Encryption 1996-1997 RSA Security Inc. All Rights Reserved.Trademark AcknowledgementsAdobe and Acrobat are trademarks or registered trademarks of Adobe Systems Incorporated in the U.S. and/or other countries.This product includes software developed by The Apache Software Foundation (http://www.apache.org/).DB2 is a registered trademark of International Business Machines Corp. in the U.S. and other countries.Java is a registered trademark of Sun Microsystems, Inc. in the U.S. and other countries. Solaris is a registered trademark ofSun Microsystems, Inc. Sun Microsystems, Inc has not tested or approved this product.Portions of this software are based in part on the work of the Independent JPEG Group.Portions of this software contain imaging code owned and copyrighted by Pegasus Imaging Corporation, Tampa, FL. All rightsreserved.Macromedia and Flash are trademarks or registered trademarks of Macromedia, Inc. in the United States and/or other countries.Microsoft, MS-DOS, Windows, Windows Media Player, Windows Server, Windows NT, Win32, Outlook, Outlook Express,Internet Explorer, ActiveX, Active Directory, Access, SQL Server, SQL Server Express Edition, and DirectShow are eitherregistered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.Netscape and Netscape Navigator are registered trademarks of Netscape Communications Corp. in the U.S. and other countries.Novell Directory Services, NDS, and NetWare are registered trademarks of Novell, Inc. in the United States and othercountries. Novell Client is a trademark of Novell, Inc.Oracle database is a registered trademark of Oracle Corporation.RealOne is a trademark of RealNetworks, Inc.SpeechMike is a trademark of Koninklijke Philips Electronics N.V.All other trademarks and registered trademarks are the property of their owners.Document Code: August 20, 2007 (SC)
C ONTENTSContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5About this Document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Target Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Finding More Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6What’s New. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Advanced Encryption Standard Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Citrix Password Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Security Considerations in a Citrix Presentation Server Deployment. . . . . . . . . . . .8Common Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9FIPS 140 and Citrix Presentation Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10TLS/SSL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13IP Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13Smart Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14Kerberos Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15Citrix Presentation Server Clients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16Virtual Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19Additional Citrix Presentation Server Security Features . . . . . . . . . . . . . . . . . .20Sample Deployments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21Sample Deployment A - Using SSL Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21How the Components Interact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22FIPS 140 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23TLS/SSL Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Smart Card Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Sample Deployment B - Using Secure Gateway (Single-Hop). . . . . . . . . . . . . . . .25How the Components Interact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25FIPS 140 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27TLS/SSL Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
4Citrix Presentation Server Security Standards and Deployment ScenariosSample Deployment C - Using Secure Gateway (Double-Hop) . . . . . . . . . . . . . . .29How the Components Interact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30FIPS 140 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Sample Deployment D - Using SSL Relay and the Web Interface . . . . . . . . . . . . .34How the Components Interact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34FIPS 140 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35TLS/SSL Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35Smart Card Logon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37Sample Deployment E - Using Password Manager and Secure Gateway (SingleHop). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37How the Components Interact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38FIPS 140 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40TLS/SSL Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
IntroductionAbout this DocumentCitrix products offer the security specialist a wide range of features for securing aCitrix Presentation Server system.When deploying Citrix Presentation Server 4.5 for Windows within largeorganizations and government environments, security standards are an importantconsideration. This document addresses common issues related to suchenvironments.This document provides an overview of the process of securing communicationsacross a range of deployment models. Details of the individual security featuresare explained in the relevant product documentation.Target AudienceThis document is designed to meet the needs of security specialists, systemsintegrators, and consultants working with government organizations worldwide.Country-Specific Government InformationSections of this document are of particular importance and relevance to certaincountries as shown in the table below. If your country is not listed, contact yourlocal Citrix representative.CountryTopicSeeUnited StatesFIPS 140TLSSmart card supportSmart card: Common Access CardKerberos authenticationpage 10page 13page 14page 15page 15
6Citrix Presentation Server Security Standards and Deployment ScenariosCountryTopicSeeCanadaFIPS 140TLSSmart card supportKerberos authenticationITS Pre-qualified Product List (IPPL)page 10page 13page 14page 15page 6United KingdomFIPS 140TLSSmart card supportKerberos authenticationpage 10page 13page 14page 15AustraliaFIPS 140TLSSmart card supportKerberos authenticationpage 10page 13page 14page 15For further information concerning issues specific to your country, contact yourlocal Citrix representative.Government of Canada ITS Pre-qualified Product List. Citrix PresentationServer 4.5 and 4.0, and MetaFrame XP with Feature Release 3 are pre-qualifiedby the Canadian Communications Security Establishment (CSE) under theInformation Technology Security (ITS) Product Pre-qualification Program(IPPP).The program is relevant to the Government of Canada procurement process andthe Canadian Common Criteria Scheme. The program pre-qualifies ITS productsfor use within the Government of Canada and facilitates the procurement of ITSproducts by government departments.Contact your Citrix representative for further details.Finding More InformationFor assistance with securing a Citrix Presentation Server deployment, thefollowing documentation is available from the Citrix Knowledge Center. To findthe Knowledge Center, go to the Support area of the Citrix Web site athttp://www.citrix.com/. The Citrix Presentation Server Administrator’s Guide explains how toinstall and configure Citrix Presentation Server on Windows servers.Included in this documentation is information about publishingapplications, configuring the Citrix XML Service, and configuring theCitrix SSL Relay to provide TLS/SSL-based communications.
7 The Web Interface Administrator’s Guide explains how to install andconfigure the Web Interface and provides information about securing WebInterface deployments using TLS/SSL-based communications. The Secure Gateway for Windows Administrator’s Guide explains how toinstall and configure Secure Gateway to provide a secure Internet gatewayfor ICA traffic traveling into and out of servers in a farm running CitrixPresentation Server. The Clients for Windows Administrator’s Guide explains how to install,configure, and deploy Citrix Presentation Server Clients for Windows. Theguide includes a chapter about client security measures and features. The Citrix Password Manager Administrator’s Guide explains how toinstall, configure and deploy Password Manager with Presentation Server.It includes details of enterprise security features such as integration withsmart cards, Kerberos, and Federated Environment Support (ADFS andSAML).What’s NewSecurity features and enhancements included in Citrix Presentation Server 4.5 forWindows are described in the following sections.Advanced Encryption Standard SupportAdvanced Encryption Standard (AES) is a Federal Information ProcessingStandard (FIPS), specifically, FIPS Publication 197, that specifies acryptographic algorithm for use by US Government organizations to protectsensitive, unclassified information.The Clients for Windows now support theAES cipher for connections using TLS.Citrix Password ManagerPassword Manager provides single sign-on access to any number of passwordprotected Windows-, Web-, and host-based applications published on computersrunning Presentation Server. Password Manager is included in the PlatinumEdition of Presentation Server.The Common Criteria target of evaluation for Presentation Server 4.5 includesCitrix Password Manager 4.5, Enterprise Edition. Throughout this guide,references are made to Password Manager where appropriate.
8Citrix Presentation Server Security Standards and Deployment ScenariosSecurity Considerations in a Citrix Presentation ServerDeploymentCitrix Presentation Server provides server-based computing to local and remoteusers through the Independent Computing Architecture (ICA) developed byCitrix.ICA is the communication protocol by which servers and client devices exchangedata in a Citrix Presentation Server environment. ICA is optimized to enhance thedelivery and performance of this exchange, even on low-bandwidth connections.The ICA protocol transports an application’s screens (and audio where relevant)from the server it is running on to the user’s client device, and returns the user’sinput to the application on the server. As an application runs on a server, CitrixPresentation Server intercepts the application’s display data and uses the ICAprotocol to send this data (on standard network protocols) to the client softwarerunning on the user’s client device.When the user types on the keyboard or moves and clicks the mouse, the clientsoftware sends this data to the application on the server. ICA requires minimalclient workstation capabilities and includes error detection and recovery,encryption, and data compression.A server farm is a grouping of computers running Citrix Presentation Server thatyou can manage as a unit, similar in principle to a network domain. Whendesigning server farms, you should keep in mind the goal of providing users withthe fastest possible application access while achieving the degree of centralizedadministration and network security that you need.In a Citrix Presentation Server deployment including the Web Interface,communication is conducted using both the ICA and HTTP protocols, amongthree different points: the computer running Citrix Presentation Server, a serverrunning the Web Interface, and a client device with a Web browser and client.In a Citrix Presentation Server deployment, you can configure encryption usingeither of the following: Citrix SSL Relay Secure GatewayThe Citrix SSL Relay component is integrated into Citrix Presentation Sever. TheSecure Gateway is provided on the Citrix Presentation Server Components CD.
9Common CriteriaCommon Criteria certification is an internationally recognized standard forevaluating the security of IT products and systems. Common Criteria certificationprovides assurance that products were thoroughly and independently tested andvalidated against a set of requirements established by the worldwide InternationalStandards Organization to ensure IT security.For customers, especially US Federal and international government agencies,Common Criteria certification is an important requirement when procuring ITproducts and systems. Common Criteria certification is also applicable to privatesector industries such as healthcare and financial.Citrix Presentation Server 4.5 for Windows, Platinum Edition, and CitrixPassword Manager 4.5 were evaluated under the terms of the UK IT SecurityEvaluation and Certification Scheme and meet the Common Criteria Part 3conformant requirements of Evaluation Assurance Level EAL2.For further details, asp?slID 162512&tlID 162515The following documents are available on the Web site: Security Target for Citrix Presentation Server 4.5 for WindowsThis document specifies the functional, environmental, and assuranceevaluation requirements for Presentation Server 4.5. Common Criteria Evaluated Configuration Guide, Citrix PresentationServer 4.5 for WindowsThis document describes the requirements and procedures for installing andconfiguring Presentation Server in accordance with the Common Criteriaevaluated deployment.The Common Criteria-evaluated configuration is similar to sampledeployment B.2 shown on page 27. Common Criteria Certification Report, Citrix Presentation Server 4.5 forWindowsThis report, prepared by the certification body (UK IT Security Evaluationand Certification Scheme Certification Body, CESG), states the outcome ofthe Common Criteria security evaluation.
10Citrix Presentation Server Security Standards and Deployment Scenarios Security Target for Citrix Password Manager 4.5This document specifies the functional, environmental, and assuranceevaluation requirements for Password Manager 4.5. Common Criteria Evaluated Configuration Guide for Citrix PasswordManager 4.5This document explains how to install and configure Citrix PasswordManager for use with the Common Criteria evaluated deployment. Theprocedures relating to Presentation Server 4.0 in this document are also validfor Presentation Server 4.5. Common Criteria Certification Report, Citrix Password Manager 4.5This report, prepared by the certification body (UK IT Security Evaluationand Certification Scheme Certification Body, CESG), states the outcome ofthe Common Criteria security evaluation.FIPS 140 and Citrix Presentation ServerFederal Information Processing Standard 140 (FIPS 140) is a US federalgovernment standard that details a benchmark for implementing cryptographicsoftware. It provides best practices for using cryptographic algorithms, managingkey elements and data buffers, and interacting with the operating system. Anevaluation process that is administered by the National Institute of Standards andTechnology’s (NIST) National Voluntary Laboratory Accreditation Program(NVLAP) allows encryption product vendors to demonstrate the extent to whichthey comply with the standard, and thus, the trustworthiness of theirimplementation.Some US government organizations restrict purchases of products that containcryptography to those that have FIPS 140-validated modules.In the UK, according to CESG published guidance at http://www.cesg.gov.uk,where the required use is for information below RESTRICTED, but stillsensitive; that is, PRIVATE, CESG recommends the use of FIPS 140-approvedproducts.The security community at large values products that follow the guidelinesdetailed in FIPS 140 and the use of FIPS 140-validated cryptographic modules.To facilitate implementing secure application server access and to meet the FIPS140 requirements, Citrix products can use cryptographic modules that areFIPS 140-validated in Windows 32-bit implementations of secure SSL/TLSconnections.The following Citrix Presentation Server components can use cryptographicmodules that are FIPS 140-validated:
11 Citrix Presentation Server Clients for Windows (including ProgramNeighborhood, Program Neighborhood Agent, and the Web Client) Secure Gateway for Windows Citrix Presentation Server Citrix SSL Relay Citrix Web InterfaceWhen using the client and server components listed above with the SSL/TLSconnection enabled, the cryptographic modules that are used are FIPS 140validated. The cryptographic modules used are those provided by the MicrosoftWindows operating system.One government ciphersuite is RSA WITH 3DES EDE CBC SHA. Asdefined in Internet RFC 2246 http://www.ietf.org/rfc/rfc2246.txt, this ciphersuiteuses RSA key exchange and TripleDES encryption.This is achieved as follows. The information below is correct at the time ofwriting; see the Microsoft documents referred to below for more recent updates: According to the Microsoft information concerning the cryptographicprovider types in the document aspx, the on
Citrix Password Manager Password Manager provides single sign-on access to any number of password-protected Windows-, Web-, and host-based applications published on computers running Presentation Server. Password Manager is
