Certification Report
Bundesamt für Sicherheit in der Informationstechnik
BSI-DSZ-CC-0235
for
IBM Tivoli Directory Server
Version 5.2
from
IBM Corporation
- Bundesamt für Sicherheit in der Informationstechnik, Postfach 20 03 63, D-53133 Bonn
Telefon +49 228 9582-0, Infoline +49 228 9582-111, Telefax +49 228 9582-455
Bundesamt für Sicherheit in der Informationstechnik
Godesberger Allee 185-189 - D-53175 Bonn - Postfach 20 03 63 - D-53133 Bonn
Telefon (0228) 9582-0 - Telefax (0228) 9582-455 - Infoline (0228) 9582-111
SOGIS-MRA
BSI-DSZ-CC-0235-2004
IBM Tivoli Directory Server
Version 5.2
from
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 for conformance to the Common Criteria for IT Security Evaluation,
Version 2.1 (ISO/IEC 15408:1999).
Evaluation Results:
Functionality: Product specific Security Target
Common Criteria Part 2 conformant
Assurance Package: Common Criteria Part 3 conformant
EAL3
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, 02. March 2004
The President of the Federal Office
for Information Security
Dr. Helmbrecht L.S.
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-0235-2004 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-0235-2004
VI
Contents
Part A: Certification
Part B: Certification Results
Part C: Excerpts from the Criteria
BSI-DSZ-CC-0235-2004 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)
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-0235-2004
A-2
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.
BSI-DSZ-CC-0235-2004 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 IBM Tivoli Directory Server Version 5.2 has undergone the
certification procedure at BSI. It is a re-certification of BSI-DSZ-CC-0207-2003.
The evaluation of the product IBM Tivoli Directory Server Version 5.2 was
conducted by atsec information security GmbH. The atsec information security
GmbH is an evaluation facility (ITSEF)6
recognised by BSI.
The sponsor, and vendor is the IBM Corporation.
The certification is concluded with
· the comparability check and
· the production of this Certification Report.
This work was completed by the BSI on ##. February 2004.
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.
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.
6
Information Technology Security Evaluation Facility
Certification Report BSI-DSZ-CC-0235-2004
A-4
4 Publication
The following Certification Results contain pages B-1 to B-30.
The product IBM Tivoli Directory Server Version 5.2 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
IBM Corporation
11501 Burnet Road
Austin, TX 78758 - USA
BSI-DSZ-CC-0235-2004 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-0235-2004
B-2
Contents of the certification results
1 Executive Summary 3
2 Identification of the TOE 9
3 Security Policy 11
4 Assumptions and Clarification of Scope 12
5 Architectural Information 14
6 Documentation 17
7 IT Product Testing 18
8 Evaluated Configuration 20
9 Results of the Evaluation 22
10 Comments/Recommendations 24
11 Annexes 25
12 Security Target 26
13 Definitions 27
14 Bibliography 29
BSI-DSZ-CC-0235-2004 Certification Report
B-3
1 Executive Summary
The Target of Evaluation (TOE) is IBM Tivoli Directory Server Version 5.2 (also
called ITDS in short). ITDS is an implementation of the Lightweight Directory
Access Protocol (LDAP) and meets the requirements of LDAP Version 3 as
defined in RFC 2251–2256 and LDAP Version 2 as defined in RFC 1777.
It is a re-certification of BSI-DSZ-CC-0207-2003. The TOE includes additional
functionality and is certified at a higher Evaluation Assurance Level. For more
details refer to the Security Target [6].
LDAP is essentially a specialised database where the update operation is less
frequent and dedicated to the common goal within the enterprise on
consolidating and unifying the management of identity. IBM Tivoli Directory
Server is built for identity management with role supports, fine-grained access
control and entry ownership.
The IBM Tivoli Directory Server is a software product only, delivered over the
Internet as a package including
- the TOE (the LDAP server and the administration daemon executables),
- user and administrative tools (like IBM Directory Server Client SDK 5.2 or
the Web Administration Tool),
- a WebSphere Application Server,
- and an IBM DB2 database.
Note: Although delivered together with the TOE, the user and administrator
tools, the WebSphere Application Server and the DB2 database are all
excluded from the TOE and are considered part of the environment. The TOE
comprises the LDAP server and the administration daemon executables
only.
The TOE environment can also include applications that are not delivered with
the IBM Directory Server, but are used as unprivileged tools, for example the
Netscape browser needed to administrate the TOE or the Adobe Acrobat
Reader to access the supplied online documentation.
The TOE provides the following evaluated security functionality:
- Identification and authentication
- Access control
- Auditing
- Management
- Reference mediation
To ensure a secure usage, a set of guidance documents is provided together
with ITDS. Details can be found in chapter 6 of this report.
Certification Report BSI-DSZ-CC-0235-2004
B-4
The TOE can use a variety of different hardware and operating system
platforms to operate on. For the operating systems used during the evaluation
of the TOE please refer to chapter 2 and 7. Please note that no hardware is
provided with the TOE.
The TOE Security Functional Requirements (SFR) used in the Security Target
are Common Criteria Part 2 conformant as shown in the following table:
Security
Functional
Requirement
Functionality
FAU_GEN.1 Audit data generation
FAU_GEN.2 User identity association
FAU_SAR.1 Audit review
FAU_SAR.2 Restricted audit review
FDP_ACC.2 Complete access control
FDP_ACF.1 Security attribute based access control
FIA_AFL.1 Authentication failure handling
FIA_ATD.1 User attribute definition
FIA_SOS.1 Verification of secrets
FIA_UAU.1 Timing of authentication
FIA_UID.1 Timing of identification
FMT_MOF.1a8
Management of security functions behaviour
FMT_MOF.1b Management of security functions behaviour
FMT_MSA.1 Management of security attributes
FMT_MSA.3 Static attribute initialisation
FMT_MTD.1 Management of TSF data
FMT_SMF.1 Specification of Management Functions
FMT_SMR.1 Security Roles
FPT_RVM.1 Non-bypassability of the TSP
8
Notation of SFR component iteration: FXX_XXX.ya means iteration “a” of the SFR
FXX_XXX.y
BSI-DSZ-CC-0235-2004 Certification Report
B-5
The TOE “IBM Tivoli Directory Server Version 5.2” was evaluated by:
atsec information security GmbH
Steinstraße 70
81667 München
Germany
The evaluation was completed on February 08, 2004. The atsec information
security GmbH is an evaluation facility recognised by BSI (ITSEF)9
.
The sponsor and developer is:
IBM Corporation
11501 Burnet Road
Austin, TX 78758
USA
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 EAL3
(Evaluation Assurance Level 3).
1.2 Functionality
The TOE ITDS provides the following Security Functions:
Name Function
Audit
F.AUDIT.1 Audit Generation
Access Control
F.ACCESS_CONTROL Access control to particular LDAP operations
Identification & Authentication
F.I&A.1 Identification & authentication of TOE user
Management
F.MANAGEMENT.1 Management of the Roles Directory Administrator,
Administrative Group Members and End User
F.MANAGEMENT.2 Management of the authentication functionality
F.MANAGEMENT.3 Management of authorisation on directory entries
9
Information Technology Security Evaluation Facility
Certification Report BSI-DSZ-CC-0235-2004
B-6
Name Function
F.MANAGEMENT.4 Management of audit functionality
Reference Mediation
F.REF_MEDIATION Non-bypassability of the TSF
Note: Only the titles of the SF and a short summary are provided here because
they are very granular and almost self-explanatory. For a precise definition of
the SF please refer to the Security Target ([6], chapter 6.1).
1.3 Strength of Function
The TOE’s strength of function is claimed SOF-basic for password based user
authentication (SFR FIA_SOS.1) only.
1.4 Summary of threats and Organisational Security Policies (OSPs)
addressed by the evaluated IT product
A summary of the threats defined in [6], chapter 3.2.1 is provided here. For the
precise description of the threats please refer to [6]:
T.ENTRY:
Unauthorised, malicious access to a resource/information protected by the
TOE.
T.ACCESS:
Unauthorised execution of operations.
T.ACCOUNT:
Security relevant actions occur without awareness by Directory
Administrators.
T.BYPASS:
Bypass of the TOE security functions.
Please note that T.ACCESS is not entirely averted by the TOE. Instead,
additional support from the TOE’s environment is needed. For information which
parts are averted by the TOE and which by the environment of the TOE, please
refer to [6], chapter 8.1 (Security Objective Rationale) and to chapter 4.3 of this
report.
The TOE has to comply to the following Organisational Security Policy (OSP).
P.PUBLIC:
Of the information under the control of the TOE, only public information
should be made available to unauthenticated or anonymous users.
BSI-DSZ-CC-0235-2004 Certification Report
B-7
1.5 Special configuration requirements
According to the Security Target the TOE can be run on
- Microsoft Windows 2000,
- IBM AIX 5.2,
- Sun Solaris 8,
- HP UX-11i
- Red Hat Advanced Server 3.0, and
- SuSE Linux Enterprise Server 8.
Please note that
- the underlying hardware and the operating system used by the Directory
Server,
- the Database used as back-end data store,
- the LDAP clients,
- the SSL module used for the protection of the path between the LDAP
clients and the server and between LDAP servers and
- the replication service between LDAP servers
are not part of the TOE. They are hence out of evaluation scope. Please refer
to [6], chapter 2.3 for more information.
No explicit restrictions on the usable hardware were made in the Security
Target [6].
1.6 Assumptions about the operating environment
The following constraints concerning the operating environment are made in the
Security Target.
The following constraints are based on the assumptions defined in [6],
chapter 3.1. They are summarised here:
A.PHYSICAL
The TOE is operated in a physically secure environment.
A.NOEVIL
The TOE Administrators (i.e. the Directory Administrator and the
Administrative Group Members) and TOE Environment Administrators are
trustworthy to perform discretionary actions in accordance with security
policies and not to interfere with the abstract machine (i.e. the hardware
and operating system software the TOE runs on).
Certification Report BSI-DSZ-CC-0235-2004
B-8
A.ADMIN
The TOE and TOE environment are competently installed and
administered.
A.COMM
It is assumed that communication links between the TOE and LDAP
clients (on external systems) are protected against unauthorised
modification and disclosure of communication data.
A.COOP
Authorised end users are trusted and expected to act in a co-operating
manner in a benign environment.
A.TIME
It is assumed that a reliable time function is provided by the TOE
environment.
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.
BSI-DSZ-CC-0235-2004 Certification Report
B-9
2 Identification of the TOE
The Target of Evaluation is called:
IBM Tivoli Directory Server Version 5.2
The IBM Tivoli Directory Server is a software product only, delivered over the
Internet as a package including:
Component TOE / Not TOE
IBM Tivoli Directory Server package
The LDAP daemon executable and
Administration daemon executable.
TOE
Installation and Configuration Tools and
GSKit 6 (SSL package only)
Not TOE
User and administrative tools (like the IBM Directory
Server Client SDK 5.2 or the Web Administration
Tool).
Not TOE
A WebSphere Application server. Not TOE
A IBM DB2 database. Not TOE
Note: Although delivered together with the TOE, the user and administrator
tools, the WebSphere Application server and the DB2 database as well as
GSKit, Installation and Configuration Tools are all excluded from the TOE. They
are considered to be part of the environment. The TOE is the LDAP server
and the administration daemon executables only.
The TOE environment can also include applications that are not delivered with
the IBM Tivoli Directory Server, but are used as unprivileged tools, for example
the Netscape browser needed to administrate the TOE or the Adobe Acrobat
Reader to access the supplied online documentation.
The TOE can be subdivided into two major components:
- The LDAP Server executable
- and the LDAP Server Administration Daemon executable.
The LDAP server may be partitioned again into two parts: the front-end and the
back-end. The front-end is the network interface to LDAP clients and the back-
end is the interface to a DB2 database. The Administration Daemon provides an
LDAP interface to clients, used for the administration of the LDAP server. For
more details refer to chapter 5.
Certification Report BSI-DSZ-CC-0235-2004
B-10
To install and configure the TOE in an certification conformant configuration the
user has to follow the guidance documentation provided in [8], [11] and [12] for
installation, and in [10] for configuration. The Security Guide [10] provides
guidance on how to configure the TOE in accordance with the Security
Target [6]. For the secure operation of the TOE document [9] has to be
followed.
BSI-DSZ-CC-0235-2004 Certification Report
B-11
3 Security Policy
The TOE is an implementation of the Lightweight Directory Access Protocol
(LDAP). Its main purpose is to provide identification and authentication, access
control and audit functionality. This is supplemented by management and non-
bypassability.
Therefore the Security Policy of the TOE is defined by the following TOE
security functional requirements:
- All SFR components being part of the CC class FIA (like FIA_SOS.1
defining the password policy constraints).
- FDP_ACC.2 and FDP_ACF.1 defining the Directory Access Control SFP, a
Security Policy that controls access to directory entries protected by the
TOE.
A detailed description/definition of the Security Policy enforced by the TOE is
given in the Security Target [6], chapter 5.1.
Certification Report BSI-DSZ-CC-0235-2004
B-12
4 Assumptions and Clarification of Scope
4.1 Usage assumptions
Based on the Organisational Security Policy to which the TOE complies the
following usage assumption exist (for the detailed and precise definition refer to
[6], chapter 3.3):
- Of the information under the control of the TOE, only information classified
as public information should be made available to unauthenticated or
anonymous users (P.PUBLIC).
Based on personnel assumptions defined in [6] the following usage conditions
exist:
- The Administrators of the TOE (i.e. Directory Administrators and Members of
the Administrative Group) and its environment are trustworthy to perform
discretionary actions in accordance with security policies and not to interfere
with the abstract machine (A.NOEVIL). Whereas abstract machine means
the hardware and operating system software the TOE runs on.
- The TOE and its environment are competently installed and administered
(A.ADMIN).
- Authorised users are expected to act in a co-operating manner in a benign
environment (A.COOP).
For a detailed description of the usage assumptions refer to the Security Target
[6], especially chapter 3.1.
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 [6], chapter 3.1):
- The TOE is operated in a physically secure environment (A.PHYSICAL).
- Communication links between TOE and LDAP clients (on external systems)
are protected against modification and disclosure of transmitted data
(A.COMM).
- A reliable time function is provided by the environment (A.TIME).
Please consider also the requirements for the evaluated configuration specified
in chapter 8 of this report.
BSI-DSZ-CC-0235-2004 Certification Report
B-13
4.3 Clarification of scope
The environmental threats listed below are not averted by the TOE. Additional
support from the operating environment of the TOE is necessary (for detailed
information about the threats and how the environment covers them refer to the
Security Target [6], chapter 3.2.2 and chapter 8.1).
TE.USAGE:
The TOE may be configured, used and administered in an insecure
manner, allowing an illegitimate user gaining access to resources or
information protected by the TOE.
TE.CRASH:
Human error or a failure of software, hardware, power supply, or an
accidental event may cause an abrupt interruption to the TOE operation,
resulting in loss or corruption of data.
TE.SOPHISTICATED:
An unauthorised individual may gain access to TOE resources or
information by using sophisticated technical attack, using IT security-
defeating tools applied to the TOE or the underlying system components.
TE.PASS:
An attacker may bypass the TOE to access resources or resources
protected by the TOE by attacking the underlying operating system or
database, in order to gain access to TOE resources and information.
Certification Report BSI-DSZ-CC-0235-2004
B-14
5 Architectural Information
General overview
The target of evaluation is the IBM Tivoli Directory Server Version 5.2 (ITDS).
ITDS is an implementation of the Lightweight Directory Access Protocol (LDAP),
which is compliant with the Internet Engineering Task Force (IETF) LDAP
Version 2 specifications, i.e. RFC 1777 and Version 3 specifications, i.e. RFC
2251 - 2256.
The server is a software only product and can be installed and operated on a
variety of hardware/software platforms (refer to chapter 7).
LDAP essentially provides access to and management of a specialised
database where the update operation is less frequent and dedicated to the
common goal within the enterprise on consolidating and unifying the
management of identity.
IBM Tivoli Directory Server is built for identity management with role support,
fine-grained access control and entry ownership. It provides the foundation for
improved security, rapid development and deployment of Web applications.
The IBM DB2 Universal Database is used as back end data store to provide
high performance, reliability and stability in an enterprise or e-business.
The IBM Tivoli Directory Server Version 5.2 is a software product only,
delivered over the Internet as a package including the TOE, user and
administrative tools, a WebSphere Application server, and a DB2 database. The
user and administrator tools, the WebSphere Application server and the DB2
database are all excluded from the TOE and are considered part of the
environment.
The TOE environment includes applications that are not delivered with the ITDS
product, but are used as unprivileged tools, for example the Netscape browser
needed to administrate the TOE or the Adobe Acrobat Reader to access the
supplied online documentation.
Major structural units of the TOE
The TOE consists of the LDAP Server and the Administration Daemon
executables as part of the product IBM Tivoli Directory Server.
User clients are connecting both to the LDAP server and to the administration
daemon, using the LDAP protocol, but using different port numbers. The LDAP
server component is providing the LDAP functionality to users and
administrators, while the administration daemon is only used by the
administrator for starting, stopping and querying the status of the TOE.
BSI-DSZ-CC-0235-2004 Certification Report
B-15
The following figure provides a more detailed overview of the TOE:
TOE security functionality
Identification and authentication
Identification and authentication are used to determine the identity of the
LDAP clients; that is, verifying that users are who they say they are. A user
name and password is used as the authentication scheme. This user
identity is used for determining access rights and for user accountability.
The administrator can manage users, set passwords for users, and place
restrictions on user-selected passwords by specifying rules in the
password policy managed by the administrator.
Access Control
After users are authenticated, it must be determined whether they have
authorisation or permission to perform the requested operation on the
specific object. Authorisation is based on access control lists (ACLs). An
ACL is a list of authorisations that can be attached to objects and
attributes in the directory. An ACL lists what type of access each user or a
group of users is allowed or denied. To make ACLs shorter and more
manageable, users with the same access rights are often put into groups.
The directory administrator can manage access control by specifying the
access rights to objects for individual users or groups.
Certification Report BSI-DSZ-CC-0235-2004
B-16
Auditing
The IBM Tivoli Directory Server can perform auditing of security-relevant
events, such as user authentication and modification to the directory tree.
The audit function provides a means for accountability by generating audit
records containing the time, user identity, and additional information about
the operation. The behaviour of the audit function, such as selection of
auditable events, as well as audit review and clearing of audit files, is
managed by the directory administrator.
Management
The IBM Tivoli Directory Server is supporting the roles of Directory
Administrator, Members of the Administrative Group and End User,
allowing the Directory Administrator to manage the functions for
identification and authentication, authorisation and audit. The Members of
the Administrative Group have a well-defined sub-set of the rights of the
Directory Administrator. Both the Directory Administrator and the Members
of the Administrative Group can manage the users and user attributes.
Reference Mediation
The IBM Tivoli Directory Server is designed that all security policy
enforcement functions are invoked and must succeed before any function
is allowed to proceed. This means e.g. that any request for access to a
directory entry is checked for access according to the rules defined before
access is granted.
BSI-DSZ-CC-0235-2004 Certification Report
B-17
6 Documentation
The following documentation is provided with the product by the developer to
the customer:
IBM Tivoli Directory Server Version 5.2 README Addendum, First
Edition (December 2003), [8]
IBM Tivoli Directory Server Administration Guide Version 5.2, SC32-
1339-00, First Edition (September 2003), [9]
Common Criteria Compliant Configuration Guide Version 5.2, First
Edition (November 2003), [10]
IBM Tivoli Directory Server Installation and Configuration Guide Version
5.2, SC32-1338-00, First Edition (October 2003), [11]
IBM Tivoli Directory Server Version 5.2, Server Readme, [12]
Server Plug-ins Reference Version 5.2, First Edition (September 2003),
[13]
C-Client SDK Programming Reference Version 5.2, First Edition (October
2003), [14]
IBM Tivoli Directory Server Version 5.2, Client Readme, [15]
IBM Tivoli Directory Server Performance Tuning Guide, Version 5.2, First
Edition (October 2003), [16]
IBM Tivoli Directory Server Version 5.2: Web Administration Tool
Readme, First Edition (September 2003), [17]
Certification Report BSI-DSZ-CC-0235-2004
B-18
7 IT Product Testing
Test configuration
The Security Target [6] defines the following platforms for running the TOE:
- Microsoft Windows 2000
- SuSE Linux Enterprise Server 8
- Red Hat Advanced Server 3.0
- IBM AIX 5.2
- Sun Solaris 8
- HPUX 11i
Developer tests have been performed on all platforms, whereas evaluator tests
were executed on a sampled subset of those platforms. Each platform was set
up in accordance with the Security Target [6] and all the relevant guidance
(refer to chapter 6 of this report).
Depth/Coverage of Testing
The security functionality of the TOE as well as all TSFI as detailed in the
Functional Specification were completely covered by the developer tests. The
developer tests provided for a sufficient depth as required by EAL3. The test
areas provided by the developer covered the subsystems as defined in the
high-level design documentation of the TOE as well as their interfaces.
Summary of Developer Testing Effort
Test configuration:
Tests have been carried out on the platforms as described above.
Testing approach:
The developer divided the testing effort needed for the TOE into several test
areas representing groups of similar functionality. Each test area comprised
several function tests that probe for the behaviour of the functions to be tested.
For each single test case, the developer provided sufficient information on the
setup of the test environment, on the instructions needed to actually run the
test, and on the results expected for that test case.
Testing results:
The developer testing for the evaluated configuration of the TOE was performed
successfully on all platforms listed above.
BSI-DSZ-CC-0235-2004 Certification Report
B-19
Summary of Evaluator Testing Effort
Test configuration
The evaluation lab performed tests on a subset of the platforms listed above. A
reasonable argument for the subset chosen was provided. The TOE was setup
as required by the Security Target and the respective guidance documentation.
Testing approach:
The evaluator testing effort comprised two test sessions. The first session
concentrated on repeating developer test cases, whereas the second session
addressed execution of tests devised by the evaluator. These evaluator tests
concentrated on features newly introduced since the previous evaluation.
Testing results:
All actual test results obtained by the evaluator matched the expected results.
Evaluator penetration testing:
Within the vulnerability analysis, the evaluator identified potential vulnerabilities
and decided to determine their potential of being exploited by devising
additional penetration tests probing for ways a potential attacker might
circumvent security functions.
The penetration tests did not show any obvious vulnerability which was
exploitable in the intended environment.
Certification Report BSI-DSZ-CC-0235-2004
B-20
8 Evaluated Configuration
The Target of Evaluation is called:
IBM Tivoli Directory Server Version 5.2
The IBM Tivoli Directory Server is a software product only, delivered over the
Internet as a package including:
Component TOE / Not TOE
IBM Tivoli Directory Server package
The LDAP daemon executable and
Administration daemon executable.
TOE
Installation and Configuration Tools and
GSKit 6 (SSL package only)
Not TOE
User and administrative tools (like the IBM Directory
Server Client SDK 5.2 or the Web Administration
Tool).
Not TOE
A WebSphere Application Server. Not TOE
A IBM DB2 database. Not TOE
Note: Although delivered together with the TOE, the user and administrator
tools, Installation and Configuration Tools, the LDAP Client, the replication
service, the WebSphere Application Server and the DB2 database as well as
GSKit are all excluded from the TOE. They are considered to be part of the
environment (refer to [6], chapter 2.3 for further details). Therefore the TOE
comprises the LDAP server and the administration daemon executables
only.
The TOE environment can also include applications that are not delivered with
the IBM Tivoli Directory Server, but are used as unprivileged tools, for example
the Netscape browser needed to administrate the TOE or the Adobe Acrobat
Reader to access the supplied online documentation.
To install and configure the TOE in an certification conformant configuration the
user has to follow the guidance documentation provided in [8], [11] and [12] for
installation, and in [10] for configuration. The Security Guide [10] provides
guidance on how to configure the TOE in accordance with the Security
Target [6]. For the secure operation of the TOE document [9] has to be
followed.
The TOE can be run on the following Operating Systems:
- Microsoft Windows 2000
- SuSE Linux Enterprise Server 8
BSI-DSZ-CC-0235-2004 Certification Report
B-21
- Red Hat Advanced Server 3.0
- IBM AIX 5.2
- Sun Solaris 8
- HPUX 11i
No restriction on the usable hardware was made in the Security Target [6].
The Administrators and members of the administrative group of the TOE and its
environment are seen as trustworthy to perform discretionary actions in
accordance with security policies. The TOE and its environment is competently
installed and administered. Authorised users are expected to act in a co-
operating manner in a benign environment.
The TOE is operated in a physically secure environment. Communication links
(between TOE and LDAP clients on external systems, and between the TOE
and external systems) are protected against modification and disclosure of
transmitted data. A reliable time is provided by the TOE environment.
For setting up / configuring the TOE all guidance documents have to be
followed (refer to chapter 6 of this report).
Certification Report BSI-DSZ-CC-0235-2004
B-22
9 Results of the Evaluation
The Evaluation Technical Report (ETR) [7] 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 certification is a re-certification
of BSI-DSZ-CC-0207-2003. The TOE includes additional functionality and is
certified at a higher Evaluation Assurance Level.
The verdicts for the CC, Part 3 assurance components (according to EAL3 and
the Security Target evaluation) are summarised in the following table:
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.3 PASS
TOE CM coverage ACM_SCP.1 PASS
Delivery and Operation CC Class ADO PASS
Delivery Procedures ADO_DEL.1 PASS
Installation, generation, and start-up procedures ADO_IGS.1 PASS
Development CC class ADV PASS
Informal functional specification ADV_FSP.1 PASS
Security enforcing high-level design ADV_HLD.2 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
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
Examination of guidance AVA_MSU.1 PASS
Strength of TOE security function evaluation AVA_SOF.1 PASS
Developer vulnerability analysis AVA_VLA.1 PASS
BSI-DSZ-CC-0235-2004 Certification Report
B-23
The evaluation has shown that the TOE fulfils the claimed strength of function
SOF-basic for the password based user authentication (SFR FIA_SOS.1).
Please note that:
- The SOF-claim only applies for the non-administrative users of the
TOE. According to the Security Target [6], chapter 5.1.9, TOE
Administrators and Administrative Group members are not subject to the
Password Policy enforced by the TOE
- The SOF-Claim is only valid if the English language is chosen for the
TOE.
Please refer to chapter 10 for more details and further comments and
recommendations.
The vulnerability assessment performed during evaluation revealed potential
vulnerabilities. None of them were either obvious or exploitable in the intended
environment.
The results of the evaluation are only applicable to the product IBM Tivoli
Directory Server Version 5.2 in the configuration as defined in the Security
Target and summarised in this report (refer to the Security Target [6] 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.
Certification Report BSI-DSZ-CC-0235-2004
B-24
10 Comments/Recommendations
The following recommendations/comments are given by the Certification Body:
R1 The guidance documentation with respect to administrative passwords
has to be followed. Because TOE Administrators and Members of the
Administrative Group are not subject to the password policy enforced by
the TOE, these administrative users have to choose strong passwords
and to change them every 90 days.
R2 The English language has to be chosen for the TOE to ensure that the
TOE’s password policy is fully applied and the SOF-Claim is valid.
C1 According to A.ADMIN it is assumed that the TOE and its IT environment
(e.g. the DB2 database back-end) is installed and administered by
competent personnel. It has to be pointed out that the fulfilment of this
assumption is crucial for the overall security.
C2 According to A.NOEVIL it is assumed that Administrators and
Administrative Group Members are trustworthy. It has to be pointed out
that the fulfilment of this assumption is crucial for the overall security,
because administrative users are allowed to erase the audit records
(refer to [6], chapter 5.1.4).
C3 The TOE is delivered via the Internet. The secure download method
offered by IBM has to be used to obtain an un-manipulated copy of the
TOE.
BSI-DSZ-CC-0235-2004 Certification Report
B-25
11 Annexes
None.
Certification Report BSI-DSZ-CC-0235-2004
B-26
12 Security Target
For the purpose of publishing, the security target [6] of the target of evaluation
(TOE) is provided within a separate document.
BSI-DSZ-CC-0235-2004 Certification Report
B-27
13 Definitions
13.1 Acronyms
ACL Access Control List
BSI Bundesamt für Sicherheit in der Informationstechnik / Federal
Office for Information Security
CC Common Criteria for IT Security Evaluation
EAL Evaluation Assurance Level
IT Information Technology
LDAP Lightweight Directory Access Protocol
PP Protection Profile
SF Security Function
SFP Security Function Policy
SOF Strength of Function
ST Security Target
TOE Target of Evaluation
TSC TSF Scope of Control
TSF TOE Security Functions
TSP TOE Security Policy
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.
Certification Report BSI-DSZ-CC-0235-2004
B-28
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.
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
behaviour 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.
BSI-DSZ-CC-0235-2004 Certification Report
B-29
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.
[5] German IT Security Certificates (BSI 7148, BSI 7149), periodically
updated list published also on the BSI Web-site
[6] Security Target BSI-DSZ-CC-0235, Version 1.5, 2003-11-10, Security
Target IBM Tivoli Directory Server Version 5.2, IBM Corporation
[7] Evaluation Technical Report BSI-DSZ-CC-0235, Version 1.3, 2004-02-08
User Guidance Documentation:
[8] IBM Tivoli Directory Server Version 5.2 README Addendum, First
Edition (December 2003).
[9] IBM Tivoli Directory Server Administration Guide Version 5.2, SC32-
1339-00, First Edition (September 2003)
[10] Common Criteria Compliant Configuration Guide Version 5.2, First
Edition (November 2003)
[11] IBM Tivoli Directory Server Installation and Configuration Guide Version
5.2, SC32-1338-00, First Edition (October 2003)
[12] IBM Tivoli Directory Server Version 5.2, Server Readme
[13] Server Plug-ins Reference Version 5.2, First Edition (September 2003)
[14] C-Client SDK Programming Reference Version 5.2, First Edition (October
2003)
[15] IBM Tivoli Directory Server Version 5.2, Client Readme
[16] IBM Tivoli Directory Server Performance Tuning Guide, Version 5.2, First
Edition (October 2003)
[17] IBM Tivoli Directory Server Version 5.2: Web Administration Tool
Readme, First Edition (September 2003)
Certification Report BSI-DSZ-CC-0235-2004
B-30
This page is intentionally left blank.
BSI-DSZ-CC-0235-2004 Certification Report
C-1
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.
Certification Report BSI-DSZ-CC-0235-2004
C-2
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“
BSI-DSZ-CC-0235-2004 Certification Report
C-3
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.
Certification Report BSI-DSZ-CC-0235-2004
C-4
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“
BSI-DSZ-CC-0235-2004 Certification Report
C-5
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,
Certification Report BSI-DSZ-CC-0235-2004
C-6
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.“
BSI-DSZ-CC-0235-2004 Certification Report
C-7
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.“