Certification Report
Bundesamt für Sicherheit in der Informationstechnik
BSI-DSZ-CC-0256-2005
for
SUSE Linux Enterprise Server Version 9
with certification-sles-ibm-eal4 package
from
Novell - SUSE LINUX AG
sponsored by
IBM Corporation
- Bundesamt für Sicherheit in der Informationstechnik, Postfach 20 03 63, D-53133 Bonn
Phone +49 228 9582-0, Fax +49 228 9582-455, Infoline +49 228 9582-111
Bundesamt für Sicherheit in der Informationstechnik
Godesberger Allee 185-189 - D-53175 Bonn - Postfach 20 03 63 - D-53133 Bonn
Phone +49 228 9582-0 - Fax +49 228 9582-455 - Infoline +49 228 9582-111
BSI-DSZ-CC-0256-2005
SUSE Linux Enterprise Server Version 9
with certification-sles-ibm-eal4 package
from
Novell - SUSE LINUX AG
sponsored by
IBM Corporation
Common Criteria Arrangement
The IT product identified in this certificate has been evaluated at an accredited and licensed/
approved evaluation facility using the Common Methodology for IT Security Evaluation, Part 1
Version 0.6, Part 2 Version 1.0 extended by CEM supplementation “ALC_FLR – Flaw remediation”,
for conformance to the Common Criteria for IT Security Evaluation, Version 2.1 (ISO/IEC
15408:1999) and including final interpretations for compliance with Common Criteria Version 2.2
and Common Methodology Part 2, Version 2.2.
Evaluation Results:
PP Conformance: Controlled Access Protection Profile (CAPP), Issue 1.d, 08.10.
Functionality: CAPP conformant plus product specific extensions
Common Criteria Part 2 extended
Assurance Package: Common Criteria Part 3 conformant
EAL4 augmented by ALC_FLR.3 (Flaw reporting procedures)
This certificate applies only to the specific version and release of the product in its evaluated
configuration and in conjunction with the complete Certification Report.
The evaluation has been conducted in accordance with the provisions of the certification scheme
of the German Federal Office for Information Security (BSI) and the conclusions of the evaluation
facility in the evaluation technical report are consistent with the evidence adduced.
The notes mentioned on the reverse side are part of this certificate.
Bonn, 09 March 2005
The President of the Federal Office
for Information Security
Dr. Helmbrecht L.S. SOGIS-MRA
The rating of the strength of functions does not include the cryptoalgorithms suitable for encryption
and decryption (see BSIG Section 4, Para. 3, Clause 2).
This certificate is not an endorsement of the IT product by the Federal Office for Information
Security or any other organisation that recognises or gives effect to this certificate, and no warranty
of the IT product by the Federal Office for Information Security or any other organisation that
recognises or gives effect to this certificate, is either expressed or implied.
BSI-DSZ-CC-0256-2005 Certification Report
V
Preliminary Remarks
Under the BSIG1
Act, the Federal Office for Information Security (BSI) has the
task of issuing certificates for information technology products.
Certification of a product is carried out on the instigation of the vendor or a
distributor, hereinafter called the sponsor.
A part of the procedure is the technical examination (evaluation) of the product
according to the security criteria published by the BSI or generally recognised
security criteria.
The evaluation is normally carried out by an evaluation facility recognised by the
BSI or by BSI itself.
The result of the certification procedure is the present Certification Report. This
report contains among others the certificate (summarised assessment) and the
detailed Certification Results.
The Certification Results contain the technical description of the security
functionality of the certified product, the details of the evaluation (strength and
weaknesses) and instructions for the user.
1
Act setting up the Federal Office for Information Security (BSI-Errichtungsgesetz, BSIG) of
17 December 1990, Bundesgesetzblatt I p. 2834
Certification Report BSI-DSZ-CC-0256-2005
VI
Contents
Part A: Certification
Part B: Certification Results
Part C: Excerpts from the Criteria
Part D: Annexes
BSI-DSZ-CC-0256-2005 Certification Report
A-1
A Certification
1 Specifications of the Certification Procedure
The certification body conducts the procedure according to the criteria laid down
in the following:
• BSIG2
• BSI Certification Ordinance3
• BSI Schedule of Costs4
• Special decrees issued by the Bundesministerium des Innern (Federal
Ministry of the Interior)
• DIN EN 45011 standard
• BSI certification: Procedural Description (BSI 7125)
• Common Criteria for IT Security Evaluation (CC), Version 2.15
• Common Methodology for IT Security Evaluation (CEM)
- Part 1, Version 0.6
- Part 2, Version 1.0
• BSI certification: Application Notes and Interpretation of the Scheme (AIS)
• CEM supplementation on “ALC_FLR – Flaw remediation”, Version 1.1,
February 2002
The use of Common Criteria Version 2.1, Common Methodology, part 2,
Version 1.0 and final interpretations as part of AIS 32 results in compliance of
the certification results with Common Criteria Version 2.2 and Common
Methodology Part 2, Version 2.2 as endorsed by the Common Criteria
recognition arrangement committees.
2
Act setting up the Federal Office for Information Security (BSI-Errichtungsgesetz, BSIG) of
17 December 1990, Bundesgesetzblatt I p. 2834
3
Ordinance on the Procedure for Issuance of a Certificate by the Federal Office for
Information Security (BSI-Zertifizierungsverordnung, BSIZertV) of 7 July 1992,
Bundesgesetzblatt I p. 1230
4
Schedule of Cost for Official Procedures of the Federal Office for Information Security (BSI-
Kostenverordnung, BSI-KostV) of 29th October 1992, Bundesgesetzblatt I p. 1838
5
Proclamation of the Bundesministerium des Innern of 22nd September 2000 in the
Bundesanzeiger p. 19445
Certification Report BSI-DSZ-CC-0256-2005
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2 Recognition Agreements
In order to avoid multiple certification of the same product in different countries
a mutual recognition of IT security certificates - as far as such certificates are
based on ITSEC or CC - under certain conditions was agreed.
2.1 ITSEC/CC - Certificates
The SOGIS-Agreement on the mutual recognition of certificates based on
ITSEC became effective on 3 March 1998. This agreement was signed by the
national bodies of Finland, France, Germany, Greece, Italy, The Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. This
agreement on the mutual recognition of IT security certificates was extended to
include certificates based on the CC for all evaluation levels (EAL 1 – EAL 7).
2.2 CC - Certificates
An arrangement (Common Criteria Arrangement) on the mutual recognition of
certificates based on the CC evaluation assurance levels up to and including
EAL 4 was signed in May 2000. It includes also the recognition of Protection
Profiles based on the CC. The arrangement was signed by the national bodies
of Australia, Canada, Finland, France, Germany, Greece, Italy, The
Netherlands, New Zealand, Norway, Spain, United Kingdom and the United
States. Israel joined the arrangement in November 2000, Sweden in February
2002, Austria in November 2002, Hungary and Turkey in September 2003,
Japan in November 2003, the Czech Republic in September 2004.
BSI-DSZ-CC-0256-2005 Certification Report
A-3
3 Performance of Evaluation and Certification
The certification body monitors each individual evaluation to ensure a uniform
procedure, a uniform interpretation of the criteria and uniform ratings.
The product SUSE Linux Enterprise Server Version 9 with certification-sles-ibm-
eal4 package has undergone the certification procedure at BSI. This is a re-
certification based on BSI-DSZ-CC-0234-2004.
The evaluation of the product SUSE Linux Enterprise Server Version 9 with
certification-sles-ibm-eal4 package was conducted by atsec Information
Security GmbH. The atsec is an evaluation facility (ITSEF)6
recognised by BSI.
The sponsor is:
IBM Inc.
Linux Technology Center
11400 Burnet Road
Austin, TX 78758
USA
The distributor is:
Novell - SUSE LINUX AG
Maxfeldstr. 5
90409 Nürnberg
Germany
The certification is concluded with
• the comparability check and
• the production of this Certification Report.
This work was completed by the BSI on 09 March 2005.
The confirmed assurance package is only valid on the condition that
• all stipulations regarding generation, configuration and operation, as
given in the following report, are observed,
• the product is operated in the environment described, where specified in
the following report.
This Certification Report only applies to the version of the product indicated
here. The validity can be extended to new versions and releases of the product,
provided the sponsor applies for re-certification of the modified product, in
accordance with the procedural requirements, and the evaluation does not
reveal any security deficiencies.
6
Information Technology Security Evaluation Facility
Certification Report BSI-DSZ-CC-0256-2005
A-4
For the meaning of the assurance levels and the confirmed strength of
functions, please refer to the excerpts from the criteria at the end of the
Certification Report.
BSI-DSZ-CC-0256-2005 Certification Report
A-5
4 Publication
The following Certification Results contain pages B-1 to B -30.
The product SUSE Linux Enterprise Server Version 9 with certification-sles-ibm-
eal4 package has been included in the BSI list of the certified products, which is
published regularly (see also Internet: http://www.bsi.bund.de). Further
information can be obtained from BSI-Infoline 0228/9582-111.
Further copies of this Certification Report can be requested from the vendor7
of
the product. The Certification Report can also be downloaded from the above-
mentioned website.
7
Novell - SUSE LINUX AG
Maxfeldstr. 5
90409 Nürnberg
Germany
BSI-DSZ-CC-0256-2005 Certification Report
B-1
B Certification Results
The following results represent a summary of
• the security target of the sponsor for the target of evaluation,
• the relevant evaluation results from the evaluation facility, and
• complementary notes and stipulations of the certification body.
Certification Report BSI-DSZ-CC-0256-2005
B-2
Contents of the certification results
1 Executive Summary 3
2 Identification of the TOE 12
3 Security Policy 13
4 Assumptions and Clarification of Scope 14
5 Architectural Information 15
6 Documentation 21
7 IT Product Testing 21
8 Evaluated Configuration 24
9 Results of the Evaluation 25
10 Evaluator Comments/Recommendations 26
11 Annexes 27
12 Security Target 27
13 Definitions 27
14 Bibliography 29
BSI-DSZ-CC-0256-2005 Certification Report
B-3
1 Executive Summary
The Target of Evaluation (TOE) is the SUSE Linux Enterprise Server Version 9
with certification-sles-ibm-eal4 package (also named SLES in short). This is a
re-certification based on BSI-DSZ-CC-0234-2004.
It is a general purpose, multi-user, multitasking Linux based operating system. It
provides a platform for a variety of applications in the governmental and
commercial environment. SLES is available on a broad range of computer
systems, ranging from departmental servers to multi-processor enterprise
servers. The SLES evaluation covers a potentially distributed, but closed
network of IBM xSeries, pSeries, zSeries, iSeries and eServer 325 servers
running the evaluated version of SLES.
The TOE includes Software components only and provides CAPP compliant
security functionality plus product specific extensions. Among these functions
are:
• Identification and Authentication
• Discretionary Access Control
• Secure Communication
• Audit
• Object reuse functionality
• Security Management
• TSF Protection
The evaluated version of the TOE can be run on the following IBM hardware
platforms: IBM xSeries, pSeries, zSeries, iSeries and eServer 325. For a
detailed description of the systems the tests were performed on, please refer to
chapter 7 of this report.
The product SUSE Linux Enterprise Server Version 9 is delivered by Novell -
SUSE LINUX AG on a CD-ROM or DVD. In addition to the software delivered
on CD-ROM/DVD the certification-sles-ibm-eal4 package has to be installed.
The ISO images (refer to chapter 2) and the additional package can be
downloaded from the SUSE ftp-server.
During the installation process the user has to verify the integrity and
authenticity of the downloaded software as described in the Evaluated
Configuration Guide [11]. The base software installed from the CD/DVD allow
the user to perform this verification by checking the digital signature of the ISO
images and the package.
For a detailed listing of the software packages please refer to chapter 2 of this
report.
Certification Report BSI-DSZ-CC-0256-2005
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For a detailed listing of guidance documents to be followed by a user of the
TOE refer to chapter 6 of this report.
The TOE Security Functional Requirements (SFR) used in the Security Target
are Common Criteria Part 2 extended as shown in the following table:
Security
Functional
Requirement
Identifier
SFRs from CC Part 2, contained in CAPP
FAU_GEN.1 Audit Data Generation
FAU_GEN.2 User Identity Association
FAU_SAR.1 Audit Review
FAU_SAR.2 Restricted Audit Review
FAU_SAR.3 Selectable Audit Review
FAU_SEL.1 Selective Audit
FAU_STG.1 Protected Audit Trail Storage
FAU_STG.3 Action in Case of Possible Audit Data Loss
FAU_STG.4 Prevention of Audit Data Loss
FDP_ACC.1 Discretionary Access Control Policy
FDP_ACF.1 Discretionary Access Control Functions
FDP_RIP.2 Full Residual Information Protection
FIA_ATD.1 User Attribute Definition
FIA_SOS.1 Verification of Secrets
FIA_UAU.7 Protected Authentication Feedback
FIA_USB.1 User-Subject Binding
FMT_MSA.1 Management of Security Attributes
FMT_MSA.3 Static Attribute Initialisation
FMT_MTD.1 Management of TSF Data
FMT_REV.1 Revocation
FMT_SMR.1 Security Roles
FPT_AMT.1 Abstract Machine Testing
FPT_RVM.1 Reference Mediation
FPT_SEP.1 Domain Separation
FPT_STM.1 Reliable Time Stamps
BSI-DSZ-CC-0256-2005 Certification Report
B-5
Security
Functional
Requirement
Identifier
SFRs from CC Part 2, contained in CAPP, substituted by
hierarchical higher ones in the ST
FIA_UAU.2 User Authentication before any Action
FIA_UID.2 User Identification before any Action
SFRs not in CC Part 2 (Part 2 extended), contained in CAPP
„Note1“
(as in [10], chapter 5.2.4)
Subject Residual Information Protection
SFRs from CC Part 2, not contained in CAPP
FMT_SMF.18
Specification of Management Functions
FCS_CKM.1 Cryptographic Key Generation
FCS_CKM.2 Cryptographic Key Distribution
FCS_COP.1 Cryptographic Operation
FDP_UCT.1 Basic Data Exchange Confidentiality
FDP_UIT.1 Data Exchange Integrity
FMT_MSA.2 Secure Security Attributes
FTP_ITC.1 Inter-TSF Trusted Channel
Note that some of the SFRs have been iterated in the Security Target. For
details on the iteration and the required security functionality please refer to [8],
chapter 5.1.
The IT product SUSE Linux Enterprise Server Version 9 with certification-sles-
ibm-eal4 package was evaluated by atsec information security GmbH. The
evaluation was completed on 09 March 2005. The atsec information security
GmbH is an evaluation facility (ITSEF)9
recognised by BSI.
8
Added because of AIS32, Final Interpretation 065
9
Information Technology Security Evaluation Facility
Certification Report BSI-DSZ-CC-0256-2005
B-6
The sponsor is:
IBM Inc.
Linux Technology Center
11400 Burnet Road
Austin, TX 78758
USA
The distributor is:
Novell - SUSE LINUX AG
Maxfeldstr. 5
90409 Nürnberg
Germany
1.1 Assurance package
The TOE security assurance requirements are based entirely on the assurance
components defined in part 3 of the Common Criteria (see part C of this report,
or [1], part 3 for details).
The TOE meets the assurance requirements of assurance level EAL4+
(Evaluation Assurance Level 4 augmented).
The assurance level is augmented by ALC_FLR.3 – Flaw reporting procedures.
For the evaluation of the CC component ALC_FLR.3 the mutually recognised
CEM supplementation “ALC_FLR – Flaw remediation”, Version 1.1, February
2002 ([5]) was used.
1.2 Functionality
The TOE SLES 9 provides the following Security Functions:
Name Function
Identification and Authentication (IA)
IA.1 User Identification and Authentication Data Management
IA.2 Common Authentication Mechanism
IA.3 Interactive Login and Related Mechanisms
IA.4 User Identity Changing
IA.5 Login Processing
Audit (AU)
AU.1 Audit Configuration
AU.2 Audit Processing
BSI-DSZ-CC-0256-2005 Certification Report
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Name Function
AU.3 Audit Record Format
AU.4 Audit Post-Processing
Discretionary Access Control (DA)
DA.1 General DAC Policy
DA.2 Permission Bits
DA.3 Access Control Lists supported by SLES
DA.4 Discretionary Access Control: IPC Objects
Object Reuse (OR)
OR.1 Object Reuse: File System Objects
OR.2 Object Reuse: IPC Objects
OR.3 Object Reuse: Memory Objects
Security Management (SM)
SM.1 Roles
SM.2 Access Control Configuration and Management
SM.3 Management of User, Group and Authentication Data
SM.4 Management of Audit Configuration
SM.5 Reliable Time Stamps
Secure Communication (SC)
SC.1 Secure Protocols
TSF Protection (TP)
TP.1 TSF Invocation Guarantees
TP.2 Kernel
TP.3 Kernel Modules
TP.4 Trusted Processes
TP.5 TSF Databases
TP.6 Internal TOE Protection Mechanisms
TP.7 Testing the TOE Protection Mechanisms
Note: Only the acronyms and the titles of the SFs are provided here because
they are very granular and almost self-explanatory. Please refer for a precise
definition of the SF to the Security Target of the TOE ([8], chapter 6.2).
Certification Report BSI-DSZ-CC-0256-2005
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1.3 Strength of Function
The TOE’s strength of function is rated ‘SOF-medium’ for the authentication
function (IA) using passwords (refer to [8], chapter 6.5).
The strength of function for the DRNG has been rated with medium according to
AIS 20 [7].
1.4 Summary of threats and Organisational Security Policies (OSPs)
addressed by the evaluated IT product
A summary of the threats defined in [8], chapter 3.2.1 is provided here. For the
precise description of the threats please refer to [8]:
T.UAUSER
An attacker (possibly, but not necessarily, an unauthorised user of the
TOE) may impersonate an authorised user of the TOE. This includes the
threat of an authorised user that tries to impersonate as another
authorised user without knowing the authentication information.
T.UAACCESS
An authorised user of the TOE may access information resources without
having permission from the person who owns, or is responsible for, the
information resource for the type of access.
T.COMPROT
An attacker (possibly, but not necessarily, an unauthorised user of the
TOE) may intercept a communication link between the TOE and another
trusted IT product to intercept or modify information transferred between
the TOE and the other trusted IT product (which may be another
instantiation of the TOE) using defined protocols (SSH or SSL) in a way
that can not be detected by the TOE or the other trusted IT product.
The TOE has to comply to the following Organisational Security Policies
(OSPs). Note that only a summary of the policies is provided here. For the
detailed and precise definition refer to [8], chapter 3.2.3:
P.AUTHORISED_USERS
Only users who have been authorised to access information within the
system may access the system.
P.NEED_TO_KNOW
The organisation must define a discretionary access control policy on a
need-to-know basis which can be modelled based on:
(i) owner of object, (ii) identity of subject attempting access to an object
and (iii) access rights (of a subject for the accessed object).
P.ACCOUNTABILITY
The users of the system shall be held accountable for their actions.
BSI-DSZ-CC-0256-2005 Certification Report
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1.5 Special configuration requirements
The configuration requirements for the TOE are defined in chapter 2.4 and
subsequent chapters of the Security Target [8] and are summarised here
(please refer to the Security Target for the precise and more detailed
description):
• The CC evaluated package set must be selected at install time in
accordance with the description provided in the Evaluated Configuration
Guide and installed accordingly;
• The following file systems are supported: the Ext3 journaling filesystem, the
ISO 9660 file system for CD-ROM drives, the process file system (procfs),
the sysfs filesystem (sysfs) used to export and handle non-process related
kernel information, the temporary filesystem (tmpfs) used as a temporary
RAM based file system and the pseudoterminal device file system (devpts)
used to provide pseudo terminal support;
• SLES supports the use of IPv4 and IPv6, only IPv4 is included;
• Both installation from CD and installation from a defined disk partition are
supported;
• The default configuration for identification and authentication are the defined
password based PAM modules. Support for other authentication options e.g.
smartcard authentication, is not included in the evaluation configuration;
• If the system console is used, it must be connected directly to the
workstation and requires the same physical protection as the workstation;
• The TOE comprises a single server machine (and optional peripherals)
running the allowed system software (refer to package list). A server running
the above listed software is referred to as a “TOE server” below. Details on
the allowed peripherals can be found in [8], chapter 2.4.2;
• Several TOE servers may be interlinked by a LAN (e.g., Ethernet or Token-
Ring), which may be joined by bridges/routers or by TOE workstations which
act as routers / gateways;
• Each TOE server within this network implements its own security policy. No
synchronisation function for those policies exists;
• If other systems are connected to the network they need to be configured
and managed by the same authority using an appropriate security policy not
conflicting with the security policy of the TOE;
Note:
A graphical user interface for system administration or any other operation is
not included in the evaluated configuration.
Certification Report BSI-DSZ-CC-0256-2005
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1.6 Assumptions about the operating environment
The following constraints concerning the allowed hardware and peripherals are
made in the Security Target (refer to [8], chapter 2.4.2):
Hardware Platform:
• IBM xSeries - model x335 type 8676
• IBM zSeries - model z990 (the TOE executes in a VM 5.1 Logical Partition)
• IBM iSeries - model 520 machine type (9406) ( OS/400 V5R3 LPAR )
• IBM pSeries - model 520 machine type 9111 with pSeries LPAR SF220_049
• IBM eServer - model 325 (based on the AMD64 (Opteron) processor),
machine type 8835
Peripherals:
• All terminals and printers supported by the TOE
(except hot pluggable devices connected via USB or IEEE 1394 (Firewire)
interfaces)
• All storage devices and backup devices supported by the TOE (hard disks,
CDROM drives, streamer drives, floppy disk drives)
(except hot pluggable devices connected via USB or IEEE 1394 (Firewire)
interfaces)
• All Ethernet and Token-Ring network adapters supported by the TOE
Note: the peripherals are physical peripherals for the xSeries, pSeries and
eServer 325 models. In the case of zSeries and iSeries the TOE is executing
within a logical partition and the peripherals used may be virtualised. The logical
partitioning software is part of the “abstract machine” and therefore part of the
TOE environment. The Evaluated Configuration Guide [11] provides the
required guidance on how to set up and configure the logical partitioning
software and how to define the logical peripheral devices such that the TOE
operates securely in the logical partitioning environment on the zSeries and
iSeries platforms.
Note: Excluding hot pluggable devices connected via USB does not exclude all
USB devices. USB keyboards and mice may be attached provided they are
connected before booting the operating system.
The following constraints concerning the operating environment are made in the
Security Target.
BSI-DSZ-CC-0256-2005 Certification Report
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The following constraints are based on the assumptions defined in [8], chapter
3.4. (Please refer to the Security Target for the precise and more detailed
definition):
Identifier Summary
A.LOCATE The processing resources of the TOE will be
located within controlled access facilities which
will prevent unauthorised physical access.
A.PROTECT The TOE hardware and software critical to
security policy enforcement will be protected from
unauthorised physical modification.
A.MANAGE Management of the TOE is done by competent
individuals.
A.NO_EVIL_ADMIN Administrative personnel are not careless, wilfully
negligent, or hostile.
A.COOP Users are co-operative.
A.UTRAIN Users are trained well enough to use the Security
functionality of the TOE appropriately.
A.UTRUST Users are trusted to accomplish some task or
group of tasks within a secure IT environment by
exercising complete control over their data.
A.NET_COMP Network components (like routers, bridges) used
are assumed to pass data without modification.
A.PEER Any other system with which the TOE
communicates is assumed to be under the same
management control and operate under the same
security policy constraints.
A.CONNECT All connections (to peripherals and network
connections) not using the secured protocols
SSH or SSL reside within the controlled access
facilities.
The following constraints are based on Security Objectives which have to be
met by the TOE environment. These objectives are defined in [8], chapter 4.2.
(Please refer to the Security Target for the precise and more detailed definition):
Identifier Summary
OE.ADMIN The responsible admin for the TOE is competent
and trustworthy.
OE.CREDEN User Authentication Data has to be treated
securely.
OE.INSTALL The installation, distribution and configuration of
Certification Report BSI-DSZ-CC-0256-2005
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Identifier Summary
hardware, software and firmware components
has to be done in a secure manner.
OE.PHYSICAL The security critical parts of the TOE are
protected from physical attack.
OE.INFO_PROTECT Information on security critical files (e.g.
configuration files, authentication databases) shall
be protected.
OE.MAINTENANCE Diagnostic facilities shall be used periodically.
OE.RECOVER Recovery Procedures after system failure must
be available.
OE.SOFTWARE_IN Only administrators shall be able to introduce new
trusted software into the system.
OE.SERIAL_LOGIN Clear screens before logging off (using serial
login devices).
OE.HW_SEP The underlying hardware has to provide
separation mechanisms.
1.7 Disclaimers
The Certification Results only apply to the version of the product indicated in the
Certificate and on the condition that all the stipulations are kept as detailed in
this Certification Report. This certificate is not an endorsement of the IT product
by the Federal Office for Information Security (BSI) or any other organisation
that recognises or gives effect to this certificate, and no warranty of the IT
product by BSI or any other organisation that recognises or gives effect to this
certificate, is either expressed or implied.
2 Identification of the TOE
The Target of Evaluation is called:
SUSE Linux Enterprise Server Version 9
with certification-sles-ibm-eal4 package
The software components of the TOE for different hardware platforms are listed
in [8] and chapter 8 of this report. Please note that no hardware is delivered
as part of the TOE.
The following guidance documents are supplied together with the TOE. The
Guidances have to be followed to ensure an certification conformant operation
of the TOE:
BSI-DSZ-CC-0256-2005 Certification Report
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• Common Criteria EAL4+ Evaluated Configuration Guide for SUSE LINUX
Enterprise Server on IBM Hardware. Version 1.17 [11]
• SUSE Linux Enterprise Server. Installation and Administration. [12]
Please refer to chapter 6 for a more detailed listing of the guidance documents.
3 Security Policy
The TOE is a Linux based multi-user multi-tasking operating system. The TOE
may provide services to several users at the same time. After successful login,
the users have access to a general computing environment, allowing the start-
up of user applications, issuing user commands at shell level, creating and
accessing files. The TOE provides adequate mechanisms to separate the users
and protect their data. Privileged commands are restricted to administrative
users.
The TOE uses the standard Unix model of normal (unprivileged) users and
administrative users that have the capability to get full root privileges.
The TOE is intended to operate in a networked environment with other
instantiations of the TOE as well as other well-behaved client systems operating
within the same management domain (refer to [8], chapter 6.1.5 for more
details). All those systems need to be configured in accordance with a defined
common security policy.
The TOE permits one or more processors and attached peripheral and storage
devices to be used by multiple users to perform a variety of functions requiring
controlled shared access to the data stored on the system. Such installations
are typical for workgroup or enterprise computing systems accessed by users
local to, or with otherwise protected access to, the computer system.
It is assumed that responsibility for the safeguarding of the data protected by
the TOE can be delegated to the TOE users.
All data is under the control of the TOE. The data is stored in named objects,
and the TOE can associate with each controlled object a description of the
access rights to that object.
All individual users are assigned a unique user identifier within the single host
system that forms the TOE. This user identifier is used as the basis for access
control decisions. The TOE authenticates the claimed identity of the user before
allowing the user to perform any further actions.
The TOE enforces controls such that access to data objects can only take place
in accordance with the access restrictions placed on that object by its owner or
administrative users. Ownership of named objects may be transferred under the
control of the access control policy.
Access rights (e.g. read, write, execute) can be assigned to data objects with
respect to subjects (users). Once a subject is granted access to an object, the
Certification Report BSI-DSZ-CC-0256-2005
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content of that object may be freely used to influence other objects accessible
to this subject.
4 Assumptions and Clarification of Scope
4.1 Usage assumptions
Based on the personnel assumptions the following usage conditions exist. Refer
to [8], chapter 3.4.2 for more details:
• The TOE is managed by competent individuals (A.MANAGE).
• Administrative personnel are not careless, willfully negligent, or hostile
(A.NO_EVIL_ADMIN).
• Users of the TOE are co-operative (A.COOP).
• Users are trained well enough to use the Security functionality of the TOE
appropriately (A.UTRAIN).
Users are trusted to accomplish some task or group of tasks within a secure IT
environment by exercising complete control over their data (A.UTRUST).
4.2 Environmental assumptions
The following assumptions about physical and connectivity aspects defined by
the Security Target have to be met (refer to Security Target [8], chapter 3.4.1
and 3.4.3):
• The TOE is located in an access controlled facility (A.LOCATE).
• The TOE (Hardware used by the TOE) is protected against physical
modification (A.PROTECT).
• Network components (like routers, bridges) used are assumed to pass data
without modification (A.NET_COMP).
• Any other system with which the TOE communicates is assumed to be
under the same management control and operate under the same security
policy constraints. (A.PEER)
• All connections (to peripherals and network connections) not using SSH or
SSL reside within the controlled access facilities (A.CONNECT).
4.3 Clarification of scope
The threats listed below have to be averted in order to support the TOE security
capabilities but are not addressed by the TOE itself. They have to be addressed
by the operating environment of the TOE (for detailed information about the
threats and how the environment may cover them refer to the Security Target
[8]).
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TE.HWMF
Loss of stored data due to hardware malfunction.
TE.COR_FILE
Accidental corruption or manipulation of files relevant for the security
without detection.
TE.HW_SEP
The underlying hardware functions of the hardware used by the TOE does
not provide sufficient capabilities to support the self-protection of the TSF.
5 Architectural Information
General Overview
SUSE Linux Enterprise Server Version 9 is a general purpose, multi-user,
multitasking Linux based operating system. It provides a platform for a variety of
applications in the governmental and commercial environment. SLES is
available on a broad range of computer systems, ranging from departmental
servers to multi-processor enterprise servers.
SLES is based on United Linux, which is a common effort of several
organisations to develop a common Linux platform designed as an enterprise
platform for server applications.
The SLES evaluation covers a potentially distributed, but closed network of IBM
servers (xSeries, pSeries, zSeries, iSeries, and eServer 325) running the
evaluated version of SLES.
The TOE Security Functions (TSF) consist of functions of SLES that run in
kernel mode plus some trusted processes. These are the functions that enforce
the security policy as defined in this Security Target. Tools and commands
executed in user mode that are used by an administrative user need also to be
trusted to manage the system in a secure way. But they are not considered to
be part of this TSF.
Also the hardware, the BootProm firmware and the logical partitioning software
(zSeries and iSeries) is considered not to be part of the TOE but part of the
TOE environment.
The TOE includes installation from CDROM and from a local hard disk partition.
The TOE includes standard networking applications, such as ftp and ssh. xinetd
is used to protect network applications which might otherwise have security
exposures.
System administration tools include the standard commands. A graphical user
interface for system administration or any other operation is not included in the
evaluated configuration.
The TOE environment also includes applications that are not evaluated, but are
used as unprivileged tools to access public system services. For example a
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HTTP server using a port above 1024 (e. g. on port 8080) may be used as a
normal application running without root privileges on top of the TOE.
Major structural units of the TOE
The TOE is structured in much the same way as many other operating systems,
especially Unix-type operating systems. It consists of a kernel, which runs in the
privileged state of the processor and provides services to applications (which
those can use by calling kernel services via the system call interface). Direct
access to the underlying abstract machine (hardware or partitioned
environment) is restricted to the kernel, so whenever an application wants to
access hardware like disk drives, network interfaces or other peripheral devices,
it has to call kernel services. The kernel then checks if the application has the
required access rights and privileges and either performs the service or rejects
the request.
The kernel is also responsible to separate the different user processes. This is
done by the management of the virtual and real memory of the TOE which
ensures that processes executing with different attributes can not directly
access memory areas of other processes but have to do so using the inter-
process communication mechanism provided by the kernel as part of its system
call interface.
The TSF of the TOE also includes a set of trusted processes, which when
initiated by a user with a system call operate with extended privileges. The
programs that represent those trusted processes on the file system are
protected by the file system discretionary access control security function
enforced by the kernel.
In addition the execution of the TOE is controlled by a set of configuration files,
which are also called the TSF database. Also those configuration files are
protected by the file system discretionary access control security function
enforced by the kernel.
Normal users – after they have been successfully authenticated by a defined
trusted process – can start untrusted applications where the kernel enforces the
security policy of the TOE when those applications request services from the
kernel via the system call interface.
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This structure is shown in the following figure:
The kernel itself is structured into a number of subsystems which are explained
in detail in the high level design of the TOE. Those are:
File and I/O Subsystem
Implements all file system object related functions. Functions include
those that allow a process to create, maintain, interact and delete file-
system objects, such as regular files, directories, symbolic links, hard links,
device special files, named pipes, and sockets.
Process Subsystem
Implements functions related to process and thread management.
Functions include those that allow the creation, scheduling, execution, and
deletion of process and thread subjects.
Memory Subsystem
Implements functions related to the management of a system’s memory
resources. Functions include those that create and manage virtual
memory, including management of page tables and paging algorithms.
Networking Subsystem
Implements UNIX and internet domain sockets as well as algorithms for
scheduling network packets.
Hardware
Trusted
Processes
TSF
DB
Untrusted
Processes
System Call Interface
Device Drivers Kernel Modules
User
Kernel
Hardware
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IPC Subsystem
Implements functions related to inter-process communication
mechanisms. Functions include those that facilitate controlled sharing of
information between processes, allowing them to share data and
synchronise their execution in order to interact with a common resource.
Audit Subsystem
Implements the kernel functions required to intercept system calls and
audit them in accordance with the auditing policy defined by the system
administrator.
Kernel Modules Subsystem
Implements an infrastructure to support loadable modules. Functions
include those that load and unload kernel modules.
Device Driver Subsystem
Implements support for various hardware devices through common,
device independent interface.
The trusted processes include the following subsystems:
Identification and Authentication
This includes all the processes that require to identify and authenticate
users. All those processes share a common set of functions (pluggable
authentication modules (PAM)) that ensure the same policy to be enforced
with respect to identification and authentication of users. Successful as
well as unsuccessful authentication attempts can be audited.
Network Applications
This includes the trusted processes implementing networking functions.
The TOE supports FTP and SSH v2 as well as setting up a secure
channel to another trusted system via the Stunnel client and server
processes using the SSL v3 protocol. The secure configuration as defined
in the Security Target restricts the cipher suites that can be used for
secure communication.
System Management
This includes the trusted commands a system administrator can use to
manage users and groups, set the time and date and check the integrity of
the underlying abstract machine.
Batch Processing
This includes the cron and at trusted processes that allow to execute user
programs at predefined time schedules. They ensure that the users are
restricted to the same security policy restrictions that also apply when they
start programs interactively.
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User Level Audit
This includes all the trusted processes and commands outside of the
kernel required to collect, store and process audit records. In addition to
those functions the TOE includes a secure system initialisation function
which brings the TOE into a secure state after it is powered on or after a
reset. This function ensures that user interaction with the TOE can only
occur after the TOE is securely initialised and in a secure state.
Security Functions
The security functions of the TOE defined in the Security Target are (refer
to Security Target [8], chapter 6.2):
• Identification and Authentication
• Audit
• Discretionary Access Control
• Object reuse functionality
• Security Management
• Secure Communication
• TSF Protection
A short summary for each function is provided here. A more detailed
description can be found in [8], chapter 6.2.
Identification and Authentication
The TOE provides identification and authentication using pluggable
authentication modules (PAM) based upon user passwords. The quality of
the passwords used can be enforced through configuration options
controlled by SLES.
Other authentication methods (e. g. Kerberos authentication, token based
authentication) that are supported by SLES as pluggable authentication
modules are not part of the evaluated configuration.
Functions to ensure a basic password strength and limit the use of the su
command and restrict root login to specific terminals are also included.
Audit
The TOE provides the capability to audit a large number of events
including individual system calls as well as events generated by trusted
processes. Audit data is collected in a configurable number of audit bin
files. When one of those files is full, the TOE switches to the next bin file
and starts an administrator defined program to process the audit records
in the bin file that just has been filled. The TOE provides a program for this
purpose that converts the audit records into a human readable format and
writes them to a sequential file or to a printer. The output could also be
redirected to a program that transfers the audit records to another
machine via a network connection.
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The system administrator can define a rule base to restrict auditing to the
events he is interested in. This includes the ability to restrict auditing to
specific events, specific users, specific objects or a combination of all of
this.
Discretionary Access Control
Discretionary Access Control (DAC) restricts access to file system objects
based on Access Control Lists (ACLs) that include the standard UNIX
permissions for user, group and others. Access control mechanisms also
protect IPC objects from unauthorised access.
The TOE includes the ext3 file system, which supports POSIX ACLs. This
allows you to define access rights to files within this type of file system
down to the granularity of a single user.
Object Reuse
File system objects as well as memory and IPC objects will be cleared
before they can be reused by a process belonging to a different user.
Security Management
The management of the security critical parameters of SLES is performed
by administrative users. A set of commands that require root privileges are
used for system management. Security parameters are stored in specific
files that are protected by the access control mechanisms of the TOE
against unauthorised access by users that are not administrative users.
Secure Communication
The TOE supports the definition of trusted channels using either the SSH
v2 or the SSL v3 protocol. In the case of SSH the TOE includes the SSH
server and client functions. Password based authentication is supported.
To use the SSL v3 protocol the TOE provides the stunnel client and server
functions. Only a restricted number of cipher suites are supported for
those protocols in the evaluated configuration. They are listed in the
Security Target.
TSF Protection
While in operation, the kernel software and data are protected by the
hardware memory protection mechanisms. The memory and process
management components of the kernel ensure a user process cannot
access kernel storage or storage belonging to other processes.
Non-kernel TSF software and data are protected by DAC and process
isolation mechanisms.
In the evaluated configuration, the reserved user ID root owns the
directories and files that define the TSF configuration. In general, files and
directories containing internal TSF data (e.g., configuration files, batch job
queues) are also protected from reading by DAC permissions.
The TOE and the hardware and firmware components are required to be
physically protected from unauthorised access. The system kernel
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mediates all access to the hardware mechanisms themselves, other than
program visible CPU instruction functions.
6 Documentation
The following documentation is provided with the product by the developer to
the customer:
[11] Common Criteria EAL4+ Evaluated Configuration Guide for
SUSE LINUX Enterprise Server on IBM Hardware. Version 1.17.
[12] SUSE Linux Enterprise Server. Installation and Administration. Books
delivered in PDF format.
7 IT Product Testing
Test configuration
The Security Target defines the following hardware basis for the TOE:
• IBM xSeries - model x335 type 8676
• IBM zSeries - model z990 (the TOE executes in a VM 5.1 Logical Partition)
• IBM iSeries - model 520 machine type (9406) ( OS/400 V5R3 LPAR )
• IBM pSeries - model 520 machine type 9111 with pSeries LPAR SF220_049
• IBM eServer - model 325 machine type 8835
Tests of a previous version (not containing some platform-independent patches
for the kernel) of the TOE have been performed on all systems mentioned
above. Tests of the final TOE version have been performed on the following
system:
xSeries 335, Machine type = 8676
2 x Intel Xeon 2 GHz with Hyperthreading
2,5 GB Memory
36GB SCSI disk
The test systems have been installed and configured following exactly the
information provided in the Evaluated Configuration Guide [11] with additional
software packages required for the test suite.
Depth/Coverage of Testing
The developer has done substantial functional testing of all externally visible
interfaces (TSFI). Internal interfaces of the High-level design have been
covered by direct and indirect testing. The evaluators repeated the developer
tests (because of the highly automated testing approach of the developer) and
conducted additional independent tests and penetrations tests.
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Summary of Developer Testing Effort
Test configuration:
The sponsor/developer has performed the tests on the hardware platforms
defined above. The software was installed and configured as in the Guidance
Documents (refer to chapter 6). Additional software was installed on the system
to perform the tests. It was argued by the developer’s Test Plan that this
additional software was within the boundary defined by the Security Target and
did not constitute a violation of the evaluated configuration.
Testing approach:
The sponsor/developer used several test suites and manual tests to test the
TOE. One of the test suites used was the LTP test suite. It is an adapted
version of tests from the Linux Test Project of which the sponsor is a member.
The tests have a common framework in which individual test cases adhere to a
common structure for setup execution and cleanup of tests. Each test case may
contain several tests of the same function, stressing different parts (for
example, base functionality, behaviour with illegal parameters and reaction to
missing privileges). Each test within a test case reports PASS respectively OK
or FAIL and the test case summary in batch mode reports PASS if all the tests
within the test case passed, otherwise FAIL.
Tests can be executed either manually by running the individual test case files
or run in batch mode by running an overall script.
Testing results:
All actual test results were consistent with the expected test results.
Summary of Evaluator Testing Effort
Test configuration:
The evaluator used the same machines as the developer (see above), but
performed the tests on systems with a previous kernel version (not containing
some platform-independent patches). The machines were conformant to the
Security Target requirements and have been set up according to the Evaluated
Configuration Guide [11].
Testing approach:
In addition to repeating all the automated developer tests, the evaluator devised
tests for a subset of the TOE. The tests are listed in the Evaluator Test Plan.
Testing results:
All actual test results were consistent with the expected test results.
Evaluator penetration testing:
The evaluators have devised a set of penetration tests based on
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• common sources for vulnerabilities of the Linux Operating System,
• findings of their evaluation work examination.
The penetration testing addressed the following security functions:
• Audit
• Discretionary Access Control
• Secure Communication
• TSF Protection
The penetration testing showed the existence of vulnerabilities but none of the
vulnerabilities were exploitable in the intended environment of the TOE.
Expansion of the results on other hardware platforms
The Security Target [8] defines the IBM xSeries model 335, IBM pSeries model
520, IBM iSeries model 520, IBM zSeries model z990 and IBM eServer model
325 with a set of supported peripherals as the hardware base for the TOE.
The IBM xSeries model 335 is a single- or double processor system using Intel
XEON processors. Since the tests have been performed both on a single and a
double processor system using the single-processor and the multi-processor
version of the kernel, the evaluation includes both a single and a double
processor configuration of the IBM xSeries model 335.
The IBM pSeries model 520 and the IBM iSeries model 520 are both multi-
processor systems based on the IBM POWER5 processor. For the pSeries
system the TOE was installed and tested in a logial partition LPAR SF220 while
in the case of the iSeries system the TOE was installed in a logical partition
using the OS/400 V5R3 LPAR software. As a consequence the results of this
evaluation apply only for a pSeries model 520 when installed in an LPAR SF220
logical partition and for an iSeries model 520 when installed in an OS/400 V5R3
LPAR logical partition.
The IBM zSeries z990 is a multi-processor system based on the IBM z
processor line. The TOE was installed in a logical partition (virtual machine)
using the IBM z/VM 5.1 product as the virtual machine monitor. The results of
this evaluation therefore only apply for the TOE installed within a virtual
machine under z/VM 5.1.
The IBM eServer model 325 is based on the AMD Opteron processor. The TOE
was installed and tested directly on the hardware. Since the tests have been
performed both on a single and a double processor system using the single-
processor and the multi-processor version of the kernel, the evaluation includes
both a single and a double processor configuration.
Neither the evaluator nor the developer did perform the full testing on any other
platform and therefore an automatic extension of the results of this evaluation to
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other platforms or other systems based on one of the processor architectures
mentioned above is not given.
8 Evaluated Configuration
According to the Security Target the evaluated configuration of the TOE is
defined as follows (refer also to the Security Target [8]):
The TOE SUSE Linux Enterprise Server Version 9 (SLES) is delivered on CD /
DVD in shrink-wrapped package to the customer. SUSE verifies the integrity of
the production CDs / DVDs by checking a production sample. The certification-
sles-ibm-eal4.rpm package as well as other packages that contain fixes must be
downloaded from the SUSE web site. Since those packages are digitally signed
the user is able and has to verify the integrity and authenticity of those
packages. Every user can verify the integrity of the packages of the distribution
by verifying their digital signature.
The configuration requirements for the TOE are defined in chapter 2.4 and
subsequent chapters of the Security Target [8] and are summarised here
(please refer to the Security Target for the precise and more detailed
description):
• The CC evaluated package set must be selected at install time in
accordance with the description provided in [11] and installed accordingly;
• The following file systems are supported: the Ext3 journaling filesystem, the
ISO 9660 file system for CD-ROM drives, the process file system (procfs),
the sysfs filesystem (sysfs) used to export and handle non-process related
kernel information, the temporary filesystem (tmpfs) used as a temporary
RAM based file system and the pseudoterminal device file system (devpts)
used to provide pseudo terminal support;
• SLES supports the use of IPv4 and IPv6, only IPv4 is included;
• Both installation from CD and installation from a defined disk partition are
supported;
• The default configuration for identification and authentication are the defined
password based PAM modules. Support for other authentication options e.g.
smartcard authentication, is not included in the evaluation configuration;
• If the system console is used, it must be connected directly to the
workstation and requires the same physical protection as the workstation;
• The TOE comprises a single server machine (and optional peripherals)
running the allowed system software (refer to package list). A server running
the above listed software is referred to as a “TOE server” below. Details on
the allowed peripherals can be found in [8], chapter 2.4.2;
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• Several TOE servers may be interlinked by a LAN (e.g., Ethernet or Token-
Ring), which may be joined by bridges / routers or by TOE workstations
which act as routers / gateways;
• Each TOE server within this network implements its own security policy. No
synchronisation function for those policies exists;
• If other systems are connected to the network they need to be configured
and managed by the same authority using an appropriate security policy not
conflicting with the security policy of the TOE.
Note:
A graphical user interface for system administration or any other operation is
not included in the evaluated configuration.
9 Results of the Evaluation
The Evaluation Technical Report (ETR) [9] was provided by the ITSEF
according to the Common Criteria [1], the Common Evaluation Methodology [2],
the requirements of the Scheme [3] and all interpretations and guidelines of the
Scheme (AIS) [4] as relevant for the TOE (this includes especially the
methodology for flaw remediation, [5]).
The verdicts for the CC, Part 3 assurance components (according to EAL4
augmented by ALC_FLR.3 and the Security Target evaluation) are summarised.
Assurance Classes and Components Verdict
Security Target CC Class ASE PASS
TOE description ASE_DES.1 PASS
Security environment ASE_ENV.1 PASS
ST introduction ASE_INT.1 PASS
Security objectives ASE_OBJ.1 PASS
PP claims ASE_PPC.1 PASS
IT security requirements ASE_REQ.1 PASS
Explicitly stated IT security requirements ASE_SRE.1 PASS
TOE summary specification ASE_TSS.1 PASS
Configuration management CC Class ACM PASS
Authorisation controls ACM_CAP.4 PASS
TOE CM coverage ACM_SCP.2 PASS
Partial CM automation ACM_AUT.1 PASS
Delivery and Operation CC Class ADO PASS
Delivery Procedures ADO_DEL.2 PASS
Installation, generation, and start-up procedures ADO_IGS.1 PASS
Development CC class ADV PASS
Informal functional specification ADV_FSP.2 PASS
Security enforcing high-level design ADV_HLD.2 PASS
Descriptive low-level design ADV_LLD.1 PASS
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Assurance Classes and Components Verdict
Subset of the implementation of the TSF ADV_IMP.1 PASS
Informal TOE security policy model ADV_SPM.1 PASS
Informal correspondence demonstration ADV_RCR.1 PASS
Guidance documents CC Class AGD PASS
Administrator guidance AGD_ADM.1 PASS
User guidance AGD_USR.1 PASS
Life cycle support CC Class ALC PASS
Identification of security measures ALC_DVS.1 PASS
Developer defined life-cycle model ALC_LCD.1 PASS
Well-defined development tools ALC_TAT.1 PASS
Flaw reporting procedures ALC_FLR.3 PASS
Tests CC Class ATE PASS
Analysis of coverage ATE_COV.2 PASS
Testing: high-level design ATE_DPT.1 PASS
Functional testing ATE_FUN.1 PASS
Independent testing - sample ATE_IND.2 PASS
Vulnerability assessment CC Class AVA PASS
Validation of analysis AVA_MSU.2 PASS
Strength of TOE security function evaluation AVA_SOF.1 PASS
Moderately resistant AVA_VLA.3 PASS
This certification is a re-certification based on BSI-DSZ-CC-0234-2004. The
evaluation has shown that the TOE fulfils the claimed strength of function for the
authentication function using passwords and for the DRNG.
There exist some vulnerabilities for the TOE but none of the vulnerabilities were
exploitable in the intended environment of the TOE.
The results of the evaluation are only applicable to the product SUSE Linux
Enterprise Server Version 9 in the configuration as defined in the Security
Target and summarised in this report (refer to the Security Target [8] and the
chapters 2, 4 and 8 of this report). The validity can be extended to new versions
and releases of the product, provided the sponsor applies for re-certification of
the modified product, and if the evaluation of the modified product does not
reveal any security deficiencies.
10 Comments/Recommendations
The User Guidance documentation (refer to chapter 6) contains necessary
information about the secure usage of the TOE. Additionally, for secure usage
of the TOE the fulfilment of the assumptions about the environment in the
Security Target [8] and the Security Target as a whole has to be taken into
account. Therefore a user/administrator has to follow the guidance in these
documents.
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11 Annexes
None.
12 Security Target
For the purpose of publishing, the Security Target [8] of the Target of Evaluation
(TOE) is provided within a separate document.
13 Definitions
13.1 Acronyms
ACL Access Control List
AMD Advanced Micro Devices, Inc.
AU Audit
BSI Bundesamt für Sicherheit in der Informationstechnik
CC Common Criteria for IT Security Evaluation
CCRA Common Criteria Recognition Arrangement
DA/DAC Discretionary Access Control
DRNG Deterministic Random Number Generator
EAL Evaluation Assurance Level
HTTP Hyper Text Transfer Protocol
IA Identification and Authentication
IPC Interprocess Communication
ISO International Organisation for Standardisation
IEEE Institute of Electrical & Electronics Engineers
IT Information Technology
LTP Linux Test Project
OSP Organisational Security Policy
OR Object Reuse
PAM Password authentication module
PCMCIA Personal Computer Memory Card International Association
PP Protection Profile
RPM Red Hat Package Manager
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SC Secure Communication
SF Security Function
SFP Security Function Policy
SFR Security Functional Requirement
SOF Strength of Function
SM Security Management
SLES SUSE Linux Enterprise Server
SSH Secure Shell
SSL Secure Sockets Layer
ST Security Target
TOE Target of Evaluation
TP TSF Protection
TSC TSF Scope of Control
TSF TOE Security Functions
TSP TOE Security Policy
TST TST mode of the DEP/PCI
USB Universal Serial Bus
YaST Yet Another Setup Tool
13.2 Glossary
Augmentation - The addition of one or more assurance component(s) from CC
Part 3 to an EAL or assurance package.
Extension - The addition to an ST or PP of functional requirements not
contained in part 2 and/or assurance requirements not contained in part 3 of the
CC.
Formal - Expressed in a restricted syntax language with defined semantics
based on well-established mathematical concepts.
Informal - Expressed in natural language.
Object - An entity within the TSC that contains or receives information and
upon which subjects perform operations.
Protection Profile - An implementation-independent set of security require-
ments for a category of TOEs that meet specific consumer needs.
Security Function - A part or parts of the TOE that have to be relied upon for
enforcing a closely related subset of the rules from the TSP.
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Security Target - A set of security requirements and specifications to be used
as the basis for evaluation of an identified TOE.
Semiformal - Expressed in a restricted syntax language with defined
semantics.
Strength of Function - A qualification of a TOE security function expressing
the minimum efforts assumed necessary to defeat its expected security
behavior by directly attacking its underlying security mechanisms.
SOF-basic - A level of the TOE strength of function where analysis shows that
the function provides adequate protection against casual breach of TOE
security by attackers possessing a low attack potential.
SOF-medium - A level of the TOE strength of function where analysis shows
that the function provides adequate protection against straightforward or
intentional breach of TOE security by attackers possessing a moderate attack
potential.
SOF-high - A level of the TOE strength of function where analysis shows that
the function provides adequate protection against deliberately planned or
organised breach of TOE security by attackers possessing a high attack
potential.
Subject - An entity within the TSC that causes operations to be performed.
Target of Evaluation - An IT product or system and its associated
administrator and user guidance documentation that is the subject of an
evaluation.
TOE Security Functions - A set consisting of all hardware, software, and
firmware of the TOE that must be relied upon for the correct enforcement of the
TSP.
TOE Security Policy - A set of rules that regulate how assets are managed,
protected and distributed within a TOE.
TSF Scope of Control - The set of interactions that can occur with or within a
TOE and are subject to the rules of the TSP.
14 Bibliography
[1] Common Criteria for Information Technology Security Evaluation,
Version 2.1, August 1999
[2] Common Methodology for Information Technology Security Evaluation
(CEM), Part 1, Version 0.6; Part 2: Evaluation Methodology, Version 1.0,
August 1999
[3] BSI certification: Procedural Description (BSI 7125)
[4] Application Notes and Interpretations of the Scheme (AIS) as relevant for
the TOE.
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[5] Application Notes and Interpretations of the Scheme AIS33, Version 2 –
“Methodologie zur Fehlerbehebung – Flaw Remediation”, 26.07.2002
[6] German IT Security Certificates (BSI 7148, BSI 7149), periodically
updated list published also on the BSI Web-site
[7] Anwendungshinweise und Interpretationen zum Schema:
Funktionalitätsklassen und Evaluationsmethodologie für deterministische
Zufallszahlengeneratoren (AIS 20). Version 2.0, 1999-12-02.
[8] Security Target BSI-DSZ-0256-2005, Version 3.10, 2005-01-17, “SUSE
Linux Enterprise Server V 9 Security Target for CAPP Compliance”, IBM
Corporation & SUSE Linux AG
[9] Evaluation Technical Report BSI-DSZ-CC-0256, 1.4, 2005-02-10, atsec
Information Security GmbH (confidential document)
[10] Controlled Access Protection Profile (CAPP), Version 1.d National Security
Agency, 1999-10-08
User Guidance Documentation:
[11] Common Criteria EAL4+ Evaluated Configuration Guide for
SUSE LINUX Enterprise Server on IBM Hardware. Version 1.17.
[12] SUSE Linux Enterprise Server. Installation and Administration. Books
delivered in PDF format.
Certification Report BSI-DSZ-CC-0256-2005
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C Excerpts from the Criteria
CC Part 1:
Caveats on evaluation results (chapter 5.4) / Final Interpretation 008
The conformance result indicates the source of the collection of requirements that is
met by a TOE or PP that passes its evaluation. This conformance result is presented
with respect to Part 2 (functional requirements), Part 3 (assurance requirements) and, if
applicable, to a pre-defined set of requirements (e.g., EAL, Protection Profile).
The conformance result consists of one of the following:
Part 2 conformant - A PP or TOE is Part 2 conformant if the functional requirements
are based only upon functional components in Part 2
Part 2 extended - A PP or TOE is Part 2 extended if the functional requirements
include functional components not in Part 2
plus one of the following:
Part 3 conformant - A PP or TOE is Part 3 conformant if the assurance requirements
are based only upon assurance components in Part 3
Part 3 extended - A PP or TOE is Part 3 extended if the assurance requirements
include assurance requirements not in Part 3.
Additionally, the conformance result may include a statement made with respect to sets
of defined requirements, in which case it consists of one of the following:
Package name Conformant - A PP or TOE is conformant to a pre-defined named
functional and/or assurance package (e.g. EAL) if the requirements (functions or
assurance) include all components in the packages listed as part of the conformance
result.
Package name Augmented - A PP or TOE is an augmentation of a pre-defined
named functional and/or assurance package (e.g. EAL) if the requirements (functions
or assurance) are a proper superset of all components in the packages listed as part of
the conformance result.
Finally, the conformance result may also include a statement made with respect to
Protection Profiles, in which case it includes the following:
PP Conformant - A TOE meets specific PP(s), which are listed as part of the
conformance result.
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CC Part 3:
Assurance categorisation (chapter 2.5)
„The assurance classes, families, and the abbreviation for each family are shown in
Table 2.1.
Assurance Class Assurance Family Abbreviated Name
Class ACM:
Configuration
management
CM automation ACM_AUT
CM capabilities ACM_CAP
CM scope ACM_SCP
Class ADO: Delivery
and operation
Delivery ADO_DEL
Installation, generation and start-up ADO_IGS
Class ADV:
Development
Functional specification ADV_FSP
High-level design ADV_HLD
Implementation representation ADV_IMP
TSF internals ADV_INT
Low-level design ADV_LLD
Representation correspondence ADV_RCR
Security policy modeling ADV_SPM
Class AGD: Guidance
documents
Administrator guidance AGD_ADM
User guidance AGD_USR
Class ALC: Life cycle
support
Development security ALC_DVS
Flaw remediation ALC_FLR
Life cycle definition ALC_LCD
Tools and techniques ALC_TAT
Class ATE: Tests Coverage ATE_COV
Depth ATE_DPT
Functional tests ATE_FUN
Independent testing ATE_IND
Class AVA:
Vulnerability
assessment
Covert channel analysis AVA_CCA
Misuse AVA_MSU
Strength of TOE security functions AVA_SOF
Vulnerability analysis AVA_VLA
Table 2.1 -Assurance family breakdown and mapping“
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Evaluation assurance levels (chapter 6)
„The Evaluation Assurance Levels (EALs) provide an increasing scale that balances
the level of assurance obtained with the cost and feasibility of acquiring that degree of
assurance. The CC approach identifies the separate concepts of assurance in a TOE
at the end of the evaluation, and of maintenance of that assurance during the
operational use of the TOE.
It is important to note that not all families and components from Part 3 are included in
the EALs. This is not to say that these do not provide meaningful and desirable
assurances. Instead, it is expected that these families and components will be
considered for augmentation of an EAL in those PPs and STs for which they provide
utility.
Evaluation assurance level (EAL) overview (chapter 6.1)
Table 6.1 represents a summary of the EALs. The columns represent a hierarchically
ordered set of EALs, while the rows represent assurance families. Each number in the
resulting matrix identifies a specific assurance component where applicable.
As outlined in the next section, seven hierarchically ordered evaluation assurance
levels are defined in the CC for the rating of a TOE's assurance. They are hierarchically
ordered inasmuch as each EAL represents more assurance than all lower EALs. The
increase in assurance from EAL to EAL is accomplished by substitution of a
hierarchically higher assurance component from the same assurance family (i.e.
increasing rigour, scope, and/or depth) and from the addition of assurance components
from other assurance families (i.e. adding new requirements).
These EALs consist of an appropriate combination of assurance components as
described in chapter 2 of this Part 3. More precisely, each EAL includes no more than
one component of each assurance family and all assurance dependencies of every
component are addressed.
While the EALs are defined in the CC, it is possible to represent other combinations of
assurance. Specifically, the notion of “augmentation“ allows the addition of assurance
components (from assurance families not already included in the EAL) or the
substitution of assurance components (with another hierarchically higher assurance
component in the same assurance family) to an EAL. Of the assurance constructs
defined in the CC, only EALs may be augmented. The notion of an “EAL minus a
constituent assurance component“ is not recognised by the CC as a valid claim.
Augmentation carries with it the obligation on the part of the claimant to justify the utility
and added value of the added assurance component to the EAL. An EAL may also be
extended with explicitly stated assurance requirements.
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Assurance
Class
Assurance
Family
Assurance Components by
Evaluation Assurance Level
EAL1 EAL2 EAL3 EAL4 EAL5 EAL6 EAL7
Configuration
management
ACM_AUT 1 1 2 2
ACM_CAP 1 2 3 4 4 5 5
ACM_SCP 1 2 3 3 3
Delivery and
operation
ADO_DEL 1 1 2 2 2 3
ADO_IGS 1 1 1 1 1 1 1
Development ADV_FSP 1 1 1 2 3 3 4
ADV_HLD 1 2 2 3 4 5
ADV_IMP 1 2 3 3
ADV_INT 1 2 3
ADV_LLD 1 1 2 2
ADV_RCR 1 1 1 1 2 2 3
ADV_SPM 1 3 3 3
Guidance
documents
AGD_ADM 1 1 1 1 1 1 1
AGD_USR 1 1 1 1 1 1 1
Life cycle
support
ALC_DVS 1 1 1 2 2
ALC_FLR
ALC_LCD 1 2 2 3
ALC_TAT 1 2 3 3
Tests ATE_COV 1 2 2 2 3 3
ATE_DPT 1 1 2 2 3
ATE_FUN 1 1 1 1 2 2
ATE_IND 1 2 2 2 2 2 3
Vulnerability
assessment
AVA_CCA 1 2 2
AVA_MSU 1 2 2 3 3
AVA_SOF 1 1 1 1 1 1
AVA_VLA 1 1 2 3 4 4
Table 6.1 - Evaluation assurance level summary“
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Evaluation assurance level 1 (EAL1) - functionally tested (chapter 6.2.1)
„Objectives
EAL1 is applicable where some confidence in correct operation is required, but the
threats to security are not viewed as serious. It will be of value where independent
assurance is required to support the contention that due care has been exercised with
respect to the protection of personal or similar information.
EAL1 provides an evaluation of the TOE as made available to the customer, including
independent testing against a specification, and an examination of the guidance
documentation provided. It is intended that an EAL1 evaluation could be successfully
conducted without assistance from the developer of the TOE, and for minimal outlay.
An evaluation at this level should provide evidence that the TOE functions in a manner
consistent with its documentation, and that it provides useful protection against
identified threats.“
Evaluation assurance level 2 (EAL2) - structurally tested (chapter 6.2.2)
„Objectives
EAL2 requires the co-operation of the developer in terms of the delivery of design
information and test results, but should not demand more effort on the part of the
developer than is consistent with good commercial practice. As such it should not
require a substantially increased investment of cost or time.
EAL2 is therefore applicable in those circumstances where developers or users require
a low to moderate level of independently assured security in the absence of ready
availability of the complete development record. Such a situation may arise when
securing legacy systems, or where access to the developer may be limited.“
Evaluation assurance level 3 (EAL3) - methodically tested and checked
(chapter 6.2.3)
„Objectives
EAL3 permits a conscientious developer to gain maximum assurance from positive
security engineering at the design stage without substantial alteration of existing sound
development practices.
EAL3 is applicable in those circumstances where developers or users require a
moderate level of independently assured security, and require a thorough investigation
of the TOE and its development without substantial re-engineering.“
Evaluation assurance level 4 (EAL4) - methodically designed, tested, and
reviewed (chapter 6.2.4)
„Objectives
EAL4 permits a developer to gain maximum assurance from positive security
engineering based on good commercial development practices which, though rigorous,
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do not require substantial specialist knowledge, skills, and other resources. EAL4 is the
highest level at which it is likely to be economically feasible to retrofit to an existing
product line.
EAL4 is therefore applicable in those circumstances where developers or users require
a moderate to high level of independently assured security in conventional commodity
TOEs and are prepared to incur additional security-specific engineering costs.“
Evaluation assurance level 5 (EAL5) - semiformally designed and tested
(chapter 6.2.5)
„Objectives
EAL5 permits a developer to gain maximum assurance from security engineering
based upon rigorous commercial development practices supported by moderate
application of specialist security engineering techniques. Such a TOE will probably be
designed and developed with the intent of achieving EAL5 assurance. It is likely that
the additional costs attributable to the EAL5 requirements, relative to rigorous
development without the application of specialised techniques, will not be large.
EAL5 is therefore applicable in those circumstances where developers or users require
a high level of independently assured security in a planned development and require a
rigorous development approach without incurring unreasonable costs attributable to
specialist security engineering techniques.“
Evaluation assurance level 6 (EAL6) - semiformally verified design and
tested (chapter 6.2.6)
„Objectives
EAL6 permits developers to gain high assurance from application of security
engineering techniques to a rigorous development environment in order to produce a
premium TOE for protecting high value assets against significant risks.
EAL6 is therefore applicable to the development of security TOEs for application in
high risk situations where the value of the protected assets justifies the additional
costs.“
Evaluation assurance level 7 (EAL7) - formally verified design and tested
(chapter 6.2.7)
„Objectives
EAL7 is applicable to the development of security TOEs for application in extremely
high risk situations and/or where the high value of the assets justifies the higher costs.
Practical application of EAL7 is currently limited to TOEs with tightly focused security
functionality that is amenable to extensive formal analysis.“
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Strength of TOE security functions (AVA_SOF) (chapter 14.3)
AVA_SOF Strength of TOE security functions
„Objectives
Even if a TOE security function cannot be bypassed, deactivated, or corrupted, it may
still be possible to defeat it because there is a vulnerability in the concept of its
underlying security mechanisms. For those functions a qualification of their security
behaviour can be made using the results of a quantitative or statistical analysis of the
security behaviour of these mechanisms and the effort required to overcome them. The
qualification is made in the form of a strength of TOE security function claim.“
Vulnerability analysis (AVA_VLA) (chapter 14.4)
AVA_VLA Vulnerability analysis
„Objectives
Vulnerability analysis is an assessment to determine whether vulnerabilities identified,
during the evaluation of the construction and anticipated operation of the TOE or by
other methods (e.g. by flaw hypotheses), could allow users to violate the TSP.
Vulnerability analysis deals with the threats that a user will be able to discover flaws
that will allow unauthorised access to resources (e.g. data), allow the ability to interfere
with or alter the TSF, or interfere with the authorised capabilities of other users.“
„Application notes
A vulnerability analysis is performed by the developer in order to ascertain the
presence of security vulnerabilities, and should consider at least the contents of all the
TOE deliverables including the ST for the targeted evaluation assurance level. The
developer is required to document the disposition of identified vulnerabilities to allow
the evaluator to make use of that information if it is found useful as a support for the
evaluator's independent vulnerability analysis.“
„Independent vulnerability analysis goes beyond the vulnerabilities identified by the
developer. The main intent of the evaluator analysis is to determine that the TOE is
resistant to penetration attacks performed by an attacker possessing a low (for
AVA_VLA.2), moderate (for AVA_VLA.3) or high (for AVA_VLA.4) attack potential.“