BSI-DSZ-CC-1106-2021
for
BDrive Windows Client
Version 3.50.89.4
from
Bundesdruckerei GmbH
BSI - Bundesamt für Sicherheit in der Informationstechnik, Postfach 20 03 63, D-53133 Bonn
Phone +49 (0)228 99 9582-0, Fax +49 (0)228 9582-5477, Infoline +49 (0)228 99 9582-111
Certification Report V1.0 CC-Zert-327 V5.4
BSI-DSZ-CC-1106-2021 (*)
Cryptographic file exchange
BDrive Windows Client, Version 3.50.89.4
from Bundesdruckerei GmbH
PP Conformance: None
Functionality: Product specific Security Target
Common Criteria Part 2 extended
Assurance: Common Criteria Part 3 conformant EAL 2
The IT Product identified in this certificate has been evaluated at an approved evaluation
facility using the Common Methodology for IT Security Evaluation (CEM), Version 3.1
extended by Scheme Interpretations for conformance to the Common Criteria for IT
Security Evaluation (CC), Version 3.1. CC and CEM are also published as ISO/IEC 15408
and ISO/IEC 18045.
(*) 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 and
Notification. For details on the validity see Certification Report part A chapter 5.
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.
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.
Bonn, 31 May 2021
For the Federal Office for Information Security
Sandro Amendola L.S.
Head of Division
Bundesamt für Sicherheit in der Informationstechnik
Godesberger Allee 185-189 - D-53175 Bonn - Postfach 20 03 63 - D-53133 Bonn
Phone +49 (0)228 99 9582-0 - Fax +49 (0)228 9582-5477 - Infoline +49 (0)228 99 9582-111
SOGIS
Recognition Agreement
Common Criteria
Recognition Arrangement
Certification Report BSI-DSZ-CC-1106-2021
his page is intentionally left blank.
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BSI-DSZ-CC-1106-2021 Certification Report
Contents
A. Certification......................................................................................................................6
1. Preliminary Remarks....................................................................................................6
2. Specifications of the Certification Procedure...............................................................6
3. Recognition Agreements..............................................................................................7
4. Performance of Evaluation and Certification................................................................8
5. Validity of the Certification Result.................................................................................8
6. Publication....................................................................................................................9
B. Certification Results.......................................................................................................10
1. Executive Summary....................................................................................................11
2. Identification of the TOE.............................................................................................13
4. Assumptions and Clarification of Scope.....................................................................14
5. Architectural Information.............................................................................................15
7. IT Product Testing.......................................................................................................16
8. Evaluated Configuration.............................................................................................17
9. Results of the Evaluation............................................................................................18
10. Obligations and Notes for the Usage of the TOE.....................................................20
11. Security Target..........................................................................................................21
12. Regulation specific aspects (eIDAS, QES)..............................................................21
13. Definitions.................................................................................................................21
14. Bibliography..............................................................................................................23
C. Excerpts from the Criteria..............................................................................................24
D. Annexes.........................................................................................................................25
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Certification Report BSI-DSZ-CC-1106-2021
A. Certification
1. 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.
2. Specifications of the Certification Procedure
The certification body conducts the procedure according to the criteria laid down in the
following:
● Act on the Federal Office for Information Security1
● BSI Certification and Approval Ordinance2
● BSI Schedule of Costs3
● Special decrees issued by the Bundesministerium des Innern (Federal Ministry of the
Interior)
● DIN EN ISO/IEC 17065 standard
● BSI certification: Scheme documentation describing the certification process (CC-
Produkte) [3]
● BSI certification: Scheme documentation on requirements for the Evaluation Facility, its
approval and licencing process (CC-Stellen) [3]
● Common Criteria for IT Security Evaluation (CC), Version 3.14
[1] also published as
ISO/IEC 15408.
1
Act on the Federal Office for Information Security (BSI-Gesetz - BSIG) of 14 August 2009,
Bundesgesetzblatt I p. 2821
2
Ordinance on the Procedure for Issuance of Security Certificates and approval by the Federal Office for
Information Security (BSI-Zertifizierungs- und -Anerkennungsverordnung - BSIZertV) of 17 December
2014, Bundesgesetzblatt 2014, part I, no. 61, p. 2231
3
Schedule of Cost for Official Procedures of the Bundesamt für Sicherheit in der Informationstechnik
(BSI-Kostenverordnung, BSI-KostV) of 3 March 2005, Bundesgesetzblatt I, p. 519
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BSI-DSZ-CC-1106-2021 Certification Report
● Common Methodology for IT Security Evaluation (CEM), Version 3.1 [2] also published
as ISO/IEC 18045
● BSI certification: Application Notes and Interpretation of the Scheme (AIS) [4]
3. 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.
3.1. European Recognition of CC – Certificates (SOGIS-MRA)
The SOGIS-Mutual Recognition Agreement (SOGIS-MRA) Version 3 became effective in
April 2010. It defines the recognition of certificates for IT-Products at a basic recognition
level and, in addition, at higher recognition levels for IT-Products related to certain SOGIS
Technical Domains only.
The basic recognition level includes Common Criteria (CC) Evaluation Assurance Levels
EAL 1 to EAL 4. For "Smartcards and similar devices" a SOGIS Technical Domain is in
place. For "HW Devices with Security Boxes" a SOGIS Technical Domains is in place, too.
In addition, certificates issued for Protection Profiles based on Common Criteria are part of
the recognition agreement.
The current list of signatory nations and approved certification schemes, details on
recognition, and the history of the agreement can be seen on the website at
https://www.sogis.eu.
The SOGIS-MRA logo printed on the certificate indicates that it is recognised under the
terms of this agreement by the related bodies of the signatory nations. A disclaimer
beneath the logo indicates the specific scope of recognition.
This certificate is recognized under SOGIS-MRA for all assurance components selected.
3.2. International Recognition of CC – Certificates (CCRA)
The international arrangement on the mutual recognition of certificates based on the CC
(Common Criteria Recognition Arrangement, CCRA-2014) has been ratified on 08
September 2014. It covers CC certificates based on collaborative Protection Profiles (cPP)
(exact use), CC certificates based on assurance components up to and including EAL 2 or
the assurance family Flaw Remediation (ALC_FLR) and CC certificates for Protection
Profiles and for collaborative Protection Profiles (cPP).
The current list of signatory nations and approved certification schemes can be seen on
the website: https://www.commoncriteriaportal.org.
The Common Criteria Recognition Arrangement logo printed on the certificate indicates
that this certification is recognised under the terms of this agreement by the related bodies
of the signatory nations. A disclaimer beneath the logo indicates the specific scope of
recognition.
This certificate is recognized under CCRA-2014 for all assurance components selected.
4
Proclamation of the Bundesministerium des Innern of 12 February 2007 in the Bundesanzeiger dated
23 February 2007, p. 3730
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Certification Report BSI-DSZ-CC-1106-2021
4. 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 BDrive Windows Client, Version 3.50.89.4 has undergone the certification
procedure at BSI.
The evaluation of the product BDrive Windows Client, Version 3.50.89.4 was conducted by
TÜV Informationstechnik GmbH. The evaluation was completed on 26 April 2021. TÜV
Informationstechnik GmbH is an evaluation facility (ITSEF)5
recognised by the certification
body of BSI.
For this certification procedure the sponsor and applicant is: Bundesdruckerei GmbH.
The product was developed by: Bundesdruckerei GmbH.
The certification is concluded with the comparability check and the production of this
Certification Report. This work was completed by the BSI.
5. Validity of the Certification Result
This Certification Report applies only to the version of the product as indicated. The
confirmed assurance package is 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, as specified in the following report
and in the Security Target.
For the meaning of the assurance components and assurance levels please refer to CC
itself. Detailed references are listed in part C of this report.
The Certificate issued confirms the assurance of the product claimed in the Security Target
at the date of certification. As attack methods evolve over time, the resistance of the
certified version of the product against new attack methods needs to be re-assessed.
Therefore, the sponsor should apply for the certified product being monitored within the
assurance continuity program of the BSI Certification Scheme (e.g. by a re-assessment or
re-certification). Specifically, if results of the certification are used in subsequent evaluation
and certification procedures, in a system integration process or if a user's risk
management needs regularly updated results, it is recommended to perform a re-
assessment on a regular e.g. annual basis.
In order to avoid an indefinite usage of the certificate when evolved attack methods would
require a re-assessment of the products resistance to state of the art attack methods, the
maximum validity of the certificate has been limited. The certificate issued on 31 May 2021
is valid until 30 May 2026. Validity can be re-newed by re-certification.
The owner of the certificate is obliged:
1. when advertising the certificate or the fact of the product's certification, to refer to
the Certification Report as well as to provide the Certification Report, the Security
5
Information Technology Security Evaluation Facility
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BSI-DSZ-CC-1106-2021 Certification Report
Target and user guidance documentation mentioned herein to any customer of the
product for the application and usage of the certified product,
2. to inform the Certification Body at BSI immediately about vulnerabilities of the
product that have been identified by the developer or any third party after issuance
of the certificate,
3. to inform the Certification Body at BSI immediately in the case that security relevant
changes in the evaluated life cycle, e.g. related to development and production sites
or processes, occur, or the confidentiality of documentation and information related
to the Target of Evaluation (TOE) or resulting from the evaluation and certification
procedure where the certification of the product has assumed this confidentiality
being maintained, is not given any longer. In particular, prior to the dissemination of
confidential documentation and information related to the TOE or resulting from the
evaluation and certification procedure that do not belong to the deliverables
according to the Certification Report part B, or for those where no dissemination
rules have been agreed on, to third parties, the Certification Body at BSI has to be
informed.
In case of changes to the certified version of the product, the validity can be extended to
the new versions and releases, provided the sponsor applies for assurance continuity (i.e.
re-certification or maintenance) of the modified product, in accordance with the procedural
requirements, and the evaluation does not reveal any security deficiencies.
6. Publication
The product BDrive Windows Client, Version 3.50.89.4 has been included in the BSI list of
certified products, which is published regularly (see also Internet: https://www.bsi.bund.de
and [5]). Further information can be obtained from BSI-Infoline +49 228 9582-111.
Further copies of this Certification Report can be requested from the developer6
of the
product. The Certification Report may also be obtained in electronic form at the internet
address stated above.
6
Bundesdruckerei GmbH
Kommandantenstraße 18
10969 Berlin
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Certification Report BSI-DSZ-CC-1106-2021
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.
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BSI-DSZ-CC-1106-2021 Certification Report
1. Executive Summary
The Target of Evaluation (TOE) defined as Bdrive Windows Client version 3.50.89.4 is the
client-side solution for storing and sharing of files of all types, developed to provide a
secure alternative solution of cloud sharing for company data.
The TOE is a software component, which implements the client-side functions of the
Bdrive System for the Windows platform. It implements a secure, distributed file storage.
Each consumer device of a user receives a unique authentication certificate, and files are
shared between all devices of the user. Optionally, a user has the possibility to share files
and folders with several other users in the same company. The storage scheme realizes
forward error correction (erase coding) together with cryptographic means for encryption
and authentication.
The Security Target [6] is the basis for this certification. It is not based on a certified
Protection Profile.
The TOE Security Assurance Requirements (SAR) are based entirely on the assurance
components defined in Part 3 of the Common Criteria (see part C or [1], Part 3 for details).
The TOE meets the assurance requirements of the Evaluation Assurance Level EAL 2.
The TOE Security Functional Requirements (SFR) relevant for the TOE are outlined in the
Security Target [6], chapter 6.2. They are selected from Common Criteria Part 2 and some
of them are newly defined. Thus the TOE is CC Part 2 extended.
The TOE Security Functional Requirements are implemented by the following TOE
Security Functionality:
TOE Security Functionality Addressed issue
Login When starting the Desktop Client, the unidentified user has to
authenticate on every login via authentication with authentication
certificate. Only after successful verification of the user’s credentials
(certificate + protection password) at the IDP, the user is allowed to
perform any further action.
Logout The user decides upon the termination of the session. The private parts of
the authentication and encryption keys are protected by the TOE upon
session termination and Cryptographic Operation.
Management of access rights
to files and folders
Every group and every user owns a unique virtual folder called root node.
A user may be a member of several groups. All subfolders and their files
refer to their root node. In order to determine all users who are allowed to
access a given folder/file, its root node has to be identified. Hence, a user
has access to a given file if
• this file is contained in his own root node, or
• this file is contained in a root node that belongs to one of his groups.
User can create new groups by transforming a directory in their private
root node into a root node of a new group. Furthermore, every member of
a group can invite or remove users.
Generation of user-specific
meta data
The user-specific meta data are generated when a file is put under control
of the TOE. The user-specific meta-data contains a checksum of the
plaintext file. These user-specific meta data are encrypted, authenticated
and then transferred to the Bdrive server. The plain file gets encrypted,
authenticated, fragmented and transferred to the Cloud storage servers.
Generation of general meta The general meta data is generated when a file is decided to be
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TOE Security Functionality Addressed issue
data transferred to the Bdrive System (user’s choice). The list of users who
have access rights to the particular file is determined via the
corresponding root node. This list makes part of these general meta data,
which are transmitted to the Bdrive Server together with the storage
locations of this file.
Key generation When a file is decided to be transferred to the Bdrive system (user’s
choice), two symmetric keys are generated by the TOE on the basis of a
seed.
File encryption Files transferred to the Bdrive system are encrypted by AES-256 in CTR
mode. Big files are split into blocks with a maximum size of 20 MB which
are encrypted blockwise.
File authentication The encrypted object is authenticated by means of HMAC. In case of big
files, each of the blocks is authenticated separately – the byte offset of
each block is appended to the data prior to authentication. Each block
gets fragmented and uploaded to the cloud storage servers. The message
authentication code (MAC) is stored on the Bdrive Server along with the
general meta data.
File fragmentation After blockwise data encryption and authentication, the encrypted block is
fragmented using a Reed-Solomon-Cauchy scheme into a number of data
chunks and parity chunks. Those are then uploaded to independent cloud
storage servers facilitating Source data exchange recovery. The exact
number of data and parity chunks is added to the general meta data.
Key encryption & decryption The keys are asymmetrically encrypted using the device-specific
encryption certificates of all authorized users’ devices. The TOE
determines these certificates from the access list associated with the root
node that will contain the previously encrypted file. All encryption
certificates are validated by the TOE before usage.
Secure channels to other
trusted IT products
The TOE connects to the IDP via TLS v1.2. In any case a mutually
authenticated TLS handshake takes place. Hence, the channel is
established with authentication of both end points. The secure channel to
the Bdrive Server is inherited from the secure channel between TOE and
IDP.
Certificate Validation The TOE performs a certificate path validation of authorized encryption
certificates before usage for key encryption. The path validation traces the
certificates’ issuer up to a self-signed root CA that is known a priori and
shipped with the TOE. Additionally the revocation status of all encryption
certificates is checked via OCSP.
Table 1: TOE Security Functionalities
For more details please refer to the Security Target [6], chapter 7.
The assets to be protected by the TOE are defined in the Security Target [6], chapter 3.1.
Based on these assets the TOE Security Problem is defined in terms of Assumptions,
Threats and Organisational Security Policies. This is outlined in the Security Target [6],
chapter 3.3, 3.4 and 3.5.
This certification covers the configurations of the TOE as outlined in chapter 8.
The vulnerability assessment results as stated within this certificate do not include a rating
for those cryptographic algorithms and their implementation suitable for encryption and
decryption (see BSIG Section 9, Para. 4, Clause 2).
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
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BSI-DSZ-CC-1106-2021 Certification Report
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 (TOE) is called:
BDrive Windows Client, Version 3.50.89.4
The following table outlines the TOE deliverables:
No Type Identifier Release Form of Delivery
1 SW TOE
(file name: Bdrive-3.50.89.4-win64-signed.exe)
Hash:
27bc09450ccf94225b15ec7622a17a12a27fa0064b
9ca4a7bc931541a8df25d6
3.50.89.4 Download from
Service portal
2 DOC Bdrive user’s guide [8]
(file name:
Bdrive_Nutzerhandbuch_Release_3_50.pdf)
Hash:
fbcac6a252eb7af54a952ae841d83b4f1e18db19c1
83a8c5cd01d4ddfc18e180
3.50 Download from
Service portal
3 DOC Operating manual for Bdrive [9]
(file name: Betriebshandbuch-Bdrive-v-1.1.pdf)
Hash:
611a1324c2a947d4d58c532d20838b968c9f16842b
a52797bdeede3164d04707
1.1 Download from
Service portal
4 DOC User interface reference document [10]
(file name: UI-Reference-Bdrive.pdf)
Hash:
8e6eb91d8662d8f8550cac804428ba51265961d26
de5e0921f85cc512b754a83
1.0 Download from
Service portal
Table 2: Deliverables of the TOE
2.1. Overview of the delivery procedure
The TOE is composed solely of the software installer. The TOE and its deliverables are
delivered via a secure download from the service portal7
of the Bundesdruckerei GmbH.
2.2. Identification of TOE by the customer
When the TOE is downloaded from the service portal of the Bundesdruckerei, the
customer can ensure the validity and integrity of the software part with the code signature
of the windows installer (official Microsoft code signing certificate of the Bundesdruckerei).
Additionally, the customer can calculate the hash value of the installer binary and check
whether it matches the hash value specified in the Security Target ([6], chapter 1.4.3]). The
7
https://support.bundesdruckerei.de/support
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Certification Report BSI-DSZ-CC-1106-2021
detailed description how to identify the correct version can be found in [8, chapter 1.1]. The
acceptance procedure reflects the steps the customer has to perform in order to accept
the delivered TOE. The provided information is sufficient to make sure that the delivered
TOE is the complete evaluated instance and to detect modification/masquerading of the
delivered TOE.
3. Security Policy
The Security Policy is expressed by the set of Security Functional Requirements and
implemented by the TOE. It covers the following issues:
● Cryptographic Support,
● User Data Protection,
● Identification and Authentication,
● Security Management,
● TOE Access, and
● Trusted Path/Channels.
4. Assumptions and Clarification of Scope
The Assumptions defined in the Security Target and some aspects of Threats and
Organisational Security Policies are not covered by the TOE itself. These aspects lead to
specific security objectives to be fulfilled by the TOE-Environment. The following topics are
of relevance:
● OE.Installation: All software components of the Bdrive system shall be properly
installed according the user guidance documentation.
● OE.Credentials: Measures shall be taken to ensure that all authorized users protect
their credentials in a way that they may not be disclosed to other individuals.
● OE.Malware: The Bdrive Client workstation shall be free from untrusted soft- and
hardware which may prevent the operating system, the other software or the hardware
from its intended behav-iour.
● OE.Admin: Administrators shall be trustworthy and well-trained in order to be aware of
security risks and respective measures to protect the installations against such security
risks.
● OE.User: Authorized users shall not actively or negligently compromise the security of
the work-station on which the TOE is installed.
● OE.Physical: The workstation on which the TOE is installed shall not fall under
temporary undetected physical control of an attacker.
● OE.TrustedBackend: The backend infrastructure required by the TOE shall be
sufficiently protected against attackers by physical and logical security measures.
● OE.Masterkey: The company that uses the Bdrive system shall have measures in place
in order to protect the confidentiality of the private part of the Company Masterkey and
the integrity of the public part, e.g. a four-eyes-principle for access to this key.
Details can be found in the Security Target [6], chapter 4.2.
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5. Architectural Information
Based on the evaluation evidence described in the CC assurance family entitled TOE
design (ADV_TDS) the TOE consists of 7 subsystems:
● User Interface: User-facing component providing ordinary graphical application windows,
desktop notifications, both taskbar and system tray icons. Furthermore offers a
convenient file explorer integration with sync status overlays and context menu entries.
● Device Authorization: Implements workflows for initial device creation and activation as
well as login. Furthermore manages the system device state (e.g. LOGGED_IN,
WAITING_FOR_ACTIVATION,…) as well as appropriate authorization credentials for
those states.
● Public Sharing: Public resources are a means to interact with 3rd party users that do not
own a Bdrive account. It allows users to either share files via a link which can be
protected by password or smsTAN authorization. Also requesting files from 3rd party
users is supported. This subsystem is outside the scope of this evaluation.
● Synchronization: The central file synchronization subsystem. It reacts on both file
system and remote updates and keeps the local and remote states in sync. This
includes adaptions for various target platforms (e.g. Windows) and might imply solving
file-system level conflicts it furthermore manages data access lists for all service specific
resources and takes care of enrolling or removing users and/or devices. Note that file
content processing is done elsewhere, this component merely schedules the required
synchronization operations.
● Cryptography: This subsystem provides all basic cryptographic primitives to other
components of the desktop client. Apart from interfaces to fundamental cryptographic
algorithms it provides a secure random number generator along with facilities for entropy
collection and takes care of X.509 certificate handling, including validation. For collecting
entropy, this component maintains taps into other system components to draw entropy
from various events triggered by external actions.
● Data & File Management: The data management subsystem provides the functionality
for data up- and download as well as the required data processing (i.e. erasure
encoding, symmetric encryption and blockwise data handling). Other parts of the system
use this component to transfer their payload data (e.g. only the file content without
further meta-data) in and out of the cloud.
● Networking: The networking subsystem provides higher level interface to the network
and encapsulates all necessary networking functionality. This includes access to the
Bdrive server, the Identity Provider, al cloud storage providers and OCSP. Note that the
contained TLS implementation is fully transparent for all other components.
6. Documentation
The evaluated documentation as outlined in table 2 is being provided with the product to
the customer. This documentation contains the required information for secure usage of
the TOE in accordance with the Security Target.
Additional obligations and notes for secure usage of the TOE as outlined in chapter 10 of
this report have to be followed.
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Certification Report BSI-DSZ-CC-1106-2021
7. IT Product Testing
7.1. Developer's Test according to ATE_FUN
TOE test configurations:
The security Target [6] has identified solely one configuration of the TOE which is running
on two different operating systems (Windows 7 and Windows 10) under evaluation. This
configuration is achieved by a strict adherence of the Guidance Documentation part [8]
and [9]. The TOE is a pure software client. The developer’s tests were performed with the
TOE in its one configuration on both operating systems (Windows 7 and Windows 10).
Testing approach:
● Tests cover the TSFI and their behavioural aspects by testing each TSFI with its actions.
● Tests considering the different roles (unknown User and authenticated User).
● Positive and negative tests are executed.
Testing results:
● The developer’s testing effort has been proven sufficient to demonstrate that the TSFIs
perform as expected.
All test cases in each test scenario were run successfully on the TOE and they all
PASSED according to their expected result.
7.2. Evaluator Tests according to ATE_IND
The following subsections describe the evaluator test concept according to ATE_IND.
Subset size is chosen:
The subset contains tests from every functionality and every TSFI that is tested by the
developer. It contains automatic and manual tests. The evaluator also checked that all
tests were performed by the developer. As the same tests can be used for all three
operating systems and the same TOE behaviour and therefore the same test results are
expected for all three operating systems, the evaluator decided to test only on Windows
108
.
Verdict for the activity:
● During the evaluator’s testing the TOE operated as specified.
● The evaluator verified the developer’s test results by executing a subset of the
developer’s tests stated in the test documentation. Therefore, the TOE passed the
evaluators testing. Altogether the tests confirm the TOE functionality as described in the
developer documents.
Therefore, the TOE passed the evaluators testing. Altogether the tests confirm the TOE
functionality as described in the developer documents.
8
This is done because, the same TOE in the solely one existing configuration is used for all three different
systems. The TOE uses some functionality of the underlying OS, like the Folder structure, which is the same
for all three operating systems. Additionally the tests do not check the exact visual layout of the system
during the functionality tests, but are based on the component trays behind the visual layout of the OS, which
are the same for all three different operating systems. Therefore, the same tests can be used for all three
operating systems and the same TOE behaviour and therefore the same test results are expected for all
three operating systems.
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7.3. Penetration Testing according to AVA_VAN
Potential vulnerabilities applicable to the TOE in its operational environment the evaluators
devised the attack scenarios for penetration tests when they were of opinion, that those
potential vulnerabilities could be exploited in the TOE’s operational environment. While
doing this, also the aspects of the security architecture description were considered for
penetration testing. All other evaluation input was used for the creation of the tests as well.
Specifically the test documentation provided by the developer was used to find out if there
are areas of concern that should be covered by tests of the evaluation body.
TOE test configuration and Test Setup:
The TOE is tested in the final operational environment and installed according to the
guidance documentation. TOE parameters for testing were only set within the allowed
limits as defined by the guidance. No invasive modifications of the TOE were done.
Penetration testing focus:
In general, the evaluator focused on suitable coverage of TSFI, subsystems and
functionality, as well as secure operation of underlying components. In detail, the following
was considered:
● Regarding the TSFI, the focus of penetration testing was put on the interfaces that are
externally accessible by the user. Finally, each TSFI was included in the penetration
testing.
● Regarding the tested subsystems and TOE functionality, the evaluator made sure, that
each subsystem and with its potentially threatened functionality is sufficiently tested.
● Regarding security relevant hardware and software in the environment, the evaluator
paid special attention to potential security issues that may derive from misuse and
misconfiguration of underlying components.
Attack scenarios having been tested:
On basis of the above explain testing focus, a penetration testing set of attack scenarios
has been created in order to test each potential vulnerability. This test set contains 11
penetration tests, which cover the explained testing focus.
Verdict for the sub-activity:
No attack scenario was actually successful in the TOE’s operation environment as defined
in [6] provided that all measures required by the developer are applied.
8. Evaluated Configuration
This certification covers the following configurations of the TOE:
The TOE is the Bdrive Windows Client version 3.50.89.4. The Security Target [6] has
identified one configuration of the TOE under evaluation, which can be installed on
different Windows platforms. The configuration is achieved by strict adherence to the
preparative guidance documentations [8] and [9].
The operational environment of the TOE in its evaluated configuration can be summarized
as follows:
● Windows 7 Professional with Extended Security Updates,
● Windows 7 Enterprise with Extended Security Updates,
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● Windows 10.
9. Results of the Evaluation
9.1. CC specific results
The Evaluation Technical Report (ETR) [7] was provided by the ITSEF according to the
Common Criteria [1], the Methodology [2], the requirements of the Scheme [3] and all
interpretations and guidelines of the Scheme (AIS) [4] as relevant for the TOE.
The Evaluation Methodology CEM [2] was used.
For RNG assessment the scheme interpretations AIS 20 was used (see [4]).
As a result of the evaluation the verdict PASS is confirmed for the following assurance
components:
● All components of the EAL 2 package including the class ASE as defined in the CC (see
also part C of this report)
The evaluation has confirmed:
● PP Conformance: None
● for the Functionality: Product specific Security Target
Common Criteria Part 2 extended
● for the Assurance: Common Criteria Part 3 conformant EAL 2
The results of the evaluation are only applicable to the TOE as defined in chapter 2 and
the configuration as outlined in chapter 8 above.
9.2. Results of cryptographic assessment
The strength of the cryptographic algorithms was not rated in the course of this certification
procedure (see BSIG Section 9, Para. 4, Clause 2). But cryptographic functionalities with a
security level of lower than 100 bits can no longer be regarded as secure without
considering the application context. Therefore, for these functionalities it shall be checked
whether the related crypto operations are appropriate for the intended system. Some
further hints and guidelines can be derived from the 'Technische Richtlinie BSI TR-02102'
(https://www.bsi.bund.de).
The following table gives an overview of the cryptographic functionalities inside the TOE to
enforce the security policy and outlines its rating from cryptographic point of view. Any
Cryptographic Functionality that is marked in column 'Security Level above 100 Bits' of the
following table with 'no' achieves a security level of lower than 100 Bits (in general context)
only.
No. Purpose Cryptographic Mechanism Standard of
Implementatio
n
Key Size in Bits Security Level
above 100
Bits
1 Generation of
symmetric
cryptographic
keys
Key Derivation through
Extraction-then-Expansion
using HMAC-SHA-256
[NIST SP 800-
56C]
256 Bits Yes
2 Generation of RSA_PKCS1_v2_2 [RFC8017] 4096 Bits Yes
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No. Purpose Cryptographic Mechanism Standard of
Implementatio
n
Key Size in Bits Security Level
above 100
Bits
asymmetric
cryptographic
keys
3 Generation of
cryptographic
keys for TLS
RSA schemes [FIPS-186-4]
Digital
Signature
Standard
(DSS)
Appendix B.3
2048 Bits or
greater
Yes
4 Symmetric
encryption and
decryption of
user data
AES-256 in CTR mode of
operation and block size 256
bits with zero padding
AES standard
as specified in
[FIPS-196] and
CTR mode as
specified in
[NIST SP
SP800-38a]
256 Bits Yes
5 Cryptographic
hashing for TLS
SHA-256, SHA-384, SHA-512 [FIPS-180-4] 256 Bits, 384
Bits, 512 Bits
Yes
6 File
authentication
HMAC using SHA-256 [FIPS180-4] for
SHA,
[RFC2104] for
HMAC
256 Bits Yes
7 Asymmetric
encryption and
decryption of
TSF data
RSAES-OAEP with SHA-256
and MGF.1 as in PKCS#1 v2.2
[RFC8017] 4096 Bits Yes
8 User private key
encryption and
decryption
PKCS#5 using PBKDF2 as key
derivation function, PBES 2 as
encryption scheme and
PBMAC1 as message
authentication scheme
[RFC2898] 256 Bits Yes
9 Hash calculation
of TSF data
SHA-256 [FIPS-180-4] - Yes
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No. Purpose Cryptographic Mechanism Standard of
Implementatio
n
Key Size in Bits Security Level
above 100
Bits
10 TLS cipher suite TLS_ECDHE_WITH_AES_128
_CBC_SHA256,
TLS_ECDHE_ECDSA_WITH_
AES_256_CBC_SHA384,
TLS_ECDHE_ECDSA_WITH_
AES_128_GCM_SHA256,
TLS_ECDHE_ECDSA_WITH_
AES_256_GCM_SHA384,
TLS_ECDHE_ECDSA_WITH_
AES_128_CCM,
TLS_ECDHE_ECDSA_WITH_
AES_256_CCM,
TLS_ECDHE_RSA_WITH_AE
S_128_CBC_SHA256,
TLS_ECDHE_RSA_WITH_AE
S_256_CBC_SHA384,
TLS_ECDHE_RSA_WITH_AE
S_128_GCM_SHA256,
TLS_ECDHE_RSA_WITH_AE
S_256_GCM_SHA384,
TLS_DHE_DSS_WITH_AES_
128_CBC_SHA256,
TLS_DHE_DSS_WITH_AES_
256_CBC_SHA256,
TLS_DHE_DSS_WITH_AES_
128_GCM_SHA256,
TLS_DHE_DSS_WITH_AES_
256_GCM_SHA384,
TLS_DHE_RSA_WITH_AES_
128_CBC_SHA256,
TLS_DHE_RSA_WITH_AES_
256_CBC_SHA256,
TLS_DHE_RSA_WITH_AES_
128_GCM_SHA256,
TLS_DHE_RSA_WITH_AES_
256_GCM_SHA384,
TLS_DHE_RSA_WITH_AES_
128_CCM,
TLS_DHE_RSA_WITH_AES_
256_CCM
[RFC5289],
[RFC7251],
[RFC5246],
[RFC5288],
[RFC6655]
128 Bits, 256
Bits, 384 Bits,
Yes
Table 3: TOE cryptographic functionality
10. Obligations and Notes for the Usage of the TOE
The documents as outlined in table 2 contain necessary information about the usage of the
TOE and all security hints therein have to be considered. In addition all aspects of
Assumptions, Threats and OSPs as outlined in the Security Target not covered by the TOE
itself need to be fulfilled by the operational environment of the TOE.
The customer or user of the product shall consider the results of the certification within his
system risk management process. In order for the evolution of attack methods and
techniques to be covered, he should define the period of time until a re-assessment of the
TOE is required and thus requested from the sponsor of the certificate.
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The limited validity for the usage of cryptographic algorithms as outlined in chapter 9 has
to be considered by the user and his system risk management process, too.
If available, certified updates of the TOE should be used. If non-certified updates or
patches are available the user of the TOE should request the sponsor to provide a re-
certification. In the meantime a risk management process of the system using the TOE
should investigate and decide on the usage of not yet certified updates and patches or
take additional measures in order to maintain system security.
11. Security Target
For the purpose of publishing, the Security Target [6] of the Target of Evaluation (TOE) is
provided within a separate document as Annex A of this report.
12. Regulation specific aspects (eIDAS, QES)
None
13. Definitions
13.1. Acronyms
ADV Development
AGD Guidance Documents
AIS Application Notes and Interpretations of the Scheme
ALC Life-Cycle Support
ARC Security Architecture
ASE Security Target Evaluation
ATE Tests
AVA Vulnerability Assessment
BSI Bundesamt für Sicherheit in der Informationstechnik / Federal Office for
Information Security, Bonn, Germany
BSIG BSI-Gesetz / Act on the Federal Office for Information Security
CCRA Common Criteria Recognition Arrangement
CC Common Criteria for IT Security Evaluation
CEM Common Methodology for Information Technology Security Evaluation
cPP Collaborative Protection Profile
EAL Evaluation Assurance Level
ETR Evaluation Technical Report
FLR Flaw remediation
IND Independent testing
IT Information Technology
ITSEF Information Technology Security Evaluation Facility
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OPE Operational user guidance
OSP Organisational Security Policy
PP Protection Profile
SAR Security Assurance Requirement
SFP Security Function Policy
SFR Security Functional Requirement
ST Security Target
TOE Target of Evaluation
TSF TOE Security Functionality
TÜViT TÜV Informationstechnik GmbH
VAN Vulnerability analysis
13.2. Glossary
Augmentation - The addition of one or more requirement(s) to a package.
Collaborative Protection Profile - A Protection Profile collaboratively developed by an
International Technical Community endorsed by the Management Committee.
Extension - The addition to an ST or PP of functional requirements not contained in CC
part 2 and/or assurance requirements not contained in CC part 3.
Formal - Expressed in a restricted syntax language with defined semantics based on well-
established mathematical concepts.
Informal - Expressed in natural language.
Object - A passive entity in the TOE, that contains or receives information, and upon which
subjects perform operations.
Package - named set of either security functional or security assurance requirements
Protection Profile - A formal document defined in CC, expressing an implementation
independent set of security requirements for a category of IT Products that meet specific
consumer needs.
Security Target - An implementation-dependent statement of security needs for a specific
identified TOE.
Semiformal - Expressed in a restricted syntax language with defined semantics.
Subject - An active entity in the TOE that performs operations on objects.
Target of Evaluation - An IT Product and its associated administrator and user guidance
documentation that is the subject of an Evaluation.
TOE Security Functionality - Combined functionality of all hardware, software, and
firmware of a TOE that must be relied upon for the correct enforcement of the SFRs.
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14. Bibliography
[1] Common Criteria for Information Technology Security Evaluation, Version 3.1,
Part 1: Introduction and general model, Revision 5, April 2017
Part 2: Security functional components, Revision 5, April 2017
Part 3: Security assurance components, Revision 5, April 2017
https://www.commoncriteriaportal.org
[2] Common Methodology for Information Technology Security Evaluation (CEM),
Evaluation Methodology, Version 3.1, Rev. 5, April 2017,
https://www.commoncriteriaportal.org
[3] BSI certification: Scheme documentation describing the certification process (CC-
Produkte) and Scheme documentation on requirements for the Evaluation Facility,
approval and licencing (CC-Stellen), https://www.bsi.bund.de/zertifizierung
[4] Application Notes and Interpretations of the Scheme (AIS) as relevant for the TOE9
https://www.bsi.bund.de/AIS
[5] German IT Security Certificates (BSI 7148), periodically updated list published also
on the BSI Website, https://www.bsi.bund.de/zertifizierungsreporte
[6] Security Target BSI-DSZ-CC-1106-2021, Version 1.00, 2021-03-16, Security Target
Bdrive Windows Client, Bundesdruckerei GmbH
[7] Evaluation Technical Report, Version 5, 2021-04-16, TÜViT (confidential document)
[8] Bdrive Nutzerhandbuch, Version 3.5, 2020-06-26, Bundesdruckerei GmbH
[9] Betriebshandbuch Bdrive, Version 1.1, 2021-02-22, Bundesdruckerei GmbH
[10] Bdrive User Interface Reference, Version 1, 2020-06-25, Bundesdruckerei GmbH
9
specifically
• AIS 20, Version 3, Funktionalitätsklassen und Evaluationsmethodologie für deterministische
Zufallszahlengeneratoren
• AIS 32, Version 7, CC-Interpretationen im deutschen Zertifizierungsschema
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C. Excerpts from the Criteria
For the meaning of the assurance components and levels the following references to the
Common Criteria can be followed:
• On conformance claim definitions and descriptions refer to CC part 1 chapter 10.5
• On the concept of assurance classes, families and components refer to CC Part 3
chapter 7.1
• On the concept and definition of pre-defined assurance packages (EAL) refer to CC
Part 3 chapters 7.2 and 8
• On the assurance class ASE for Security Target evaluation refer to CC Part 3
chapter 12
• On the detailed definitions of the assurance components for the TOE evaluation
refer to CC Part 3 chapters 13 to 17
• The table in CC part 3 , Annex E summarizes the relationship between the
evaluation assurance levels (EAL) and the assurance classes, families and
components.
The CC are published at https://www.commoncriteriaportal.org/cc/
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D. Annexes
List of annexes of this certification report
Annex A: Security Target provided within a separate document.
Note: End of report
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