The purpose of the first set of Collaborative Protection Profiles (cPPs) for Full Drive Encryption (FDE): Authorization Acquisition (AA) and Encryption Engine (EE) is to provide requirements for Data-at-Rest protection for a lost device that contains storage. These cPPs allow FDE solutions based in software and/or hardware to meet the requirements. The form factor for a storage device may vary, but could include: system hard drives/solid state drives in servers, workstations, laptops, mobile devices, tablets, and external media. A hardware solution could be a Self-Encrypting Drive or other hardware-based solutions; the interface (USB, SATA, etc.) used to connect the storage device to the host machine is outside the scope of this cPP.
Full Drive Encryption encrypts all data (with certain exceptions) on the storage device and permits access to the data only after successful authorization to the FDE solution. The exceptions include the necessity to leave a portion of the storage device (the size may vary based on implementation) unencrypted for such things as the Master Boot Record (MBR) or other AA/EE pre-authentication software. These FDEcPPs interpret the term “full drive encryption” to allow FDE solutions to leave a portion of the storage device unencrypted so long as it contains plaintext user or plaintext authorization data.
Since the FDEcPPs support a variety of solutions, two cPPs describe the requirements for the FDE components shown in Figure 1.
The FDEcPP - Authorization Acquisition describes the requirements for the Authorization Acquisition piece and details the security requirements and assurance activities necessary to interact with a user and result in the availability of sending a Border Encryption Value (BEV) to the Encryption Engine.
The FDEcPP - Encryption Engine describes the requirements for the Encryption Engine piece and details the necessary security requirements and assurance activities for the actual encryption/decryption of the data by the DEK. Each cPP will also have a set of core requirements for management functions, proper handling of cryptographic keys, updates performed in a trusted manner, audit and self-tests.
This TOE description defines the scope and functionality of the Authorization Acquisition, and
the Security Problem Definition describes the assumptions made about the operating
environment and the threats to the AA that the cPP requirements address
1.2 Terms
The following sections list Common Criteria and technology terms used in this document.
1.2.1 Common Criteria Terms
Assurance
Grounds for confidence that a TOE meets the SFRs [CC].
Base Protection Profile (Base-PP)
Protection Profile used as a basis to build a PP-Configuration.
Collaborative Protection Profile (cPP)
A Protection Profile developed by
international technical communities and approved by multiple schemes.
Common Criteria (CC)
Common Criteria for Information Technology Security Evaluation (International Standard ISO/IEC 15408).
Common Criteria Testing Laboratory
Within the context of the Common Criteria Evaluation and Validation Scheme (CCEVS), an IT security evaluation facility
accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) and approved by the NIAP Validation Body to conduct Common Criteria-based evaluations.
Common Evaluation Methodology (CEM)
Common Evaluation Methodology for Information Technology Security Evaluation.
Direct Rationale
A type of Protection Profile, PP-Module, or Security Target in which the security
problem definition (SPD) elements are mapped directly to the SFRs and possibly to the
security objectives for the operational environment. There are no security objectives
for the TOE.
Extended Package (EP)
A deprecated document form for collecting SFRs that implement a particular protocol, technology,
or functionality. See Functional Packages.
Functional Package (FP)
A document that collects SFRs for a particular protocol, technology,
or functionality.
Operational Environment (OE)
Hardware and software that are outside the TOE boundary that support the TOE functionality and security policy.
Protection Profile (PP)
An implementation-independent set of security requirements for a category of products.
The security functionality of the product under evaluation.
TOE Summary Specification (TSS)
A description of how a TOE satisfies the SFRs in an ST.
1.2.2 Technical Terms
Authorization Factor
A value that a user knows, has, or is (e.g. password, token, etc.)
submitted to the TOE to establish that the user is in the community
authorized to use the hard disk. This value is used in the derivation or
decryption of the BEV and eventual decryption of the DEK. Note
that these values may or may not be used to establish the particular
identity of the user.
Border Encryption Value (BEV)
A value passed from the FDE Authorization
Acquisition (AA) to the FDE Encryption Engine (EE) intended to link the key chains
of the two components.
Refers to partitions of logical blocks of user accessible data as
managed by the host system that indexes and partitions and an
operating system that maps authorization to read or write data to blocks
in these partitions. For the sake of this Security Program Definition
(SPD) and cPP, FDE performs encryption and authorization on one
partition, so defined and supported by the OS and file system jointly,
under consideration. FDE products encrypt all data (with certain
exceptions) on the partition of the storage device and permits access to
the data only after successful authorization to the FDE solution. The
exceptions include the necessity to leave a portion of the storage device
(the size may vary based on implementation) unencrypted for such
things as the Master Boot Record (MBR) or other AA/EE preauthentication software. These FDE cPPs interpret the term “full drive
encryption” to allow FDE solutions to leave a portion of the storage
device unencrypted so long as it contains no protected data.
Host Platform
The local hardware and software the TOE is running on, and does not
include any peripheral devices (e.g. USB devices) that may be
connected to the local hardware and software.
Intermediate Key
A key used in a point between the initial user authorization and the
DEK.
Key Chaining
The method of using multiple layers of encryption keys to protect data. A top layer key encrypts a lower layer key which encrypts the data;
this method can have any number of layers.
Key Encryption Key (KEK)
A key used to encrypt other keys, such as DEKs or storage that
contains keys.
Key Material
Key material is commonly known as critical security parameter (CSP)
data, and also includes authorization data, nonces, and metadata.
Key Release Key (KRK)
A key used to release another key from storage, it is not used for the
direct derivation or decryption of another key.
Key Sanitization
A method of sanitizing encrypted data by securely overwriting the key
that was encrypting the data.
Non-Volatile Memory
A type of computer memory that will retain information without
power.
Operating System (OS)
Software which runs at the highest privilege level and can directly
control hardware resources.
This refers to all data on the storage device with the exception of a
small portion required for the TOE to function correctly. It is all space
on the disk a user could write data to and includes the operating
system, applications, and user data. Protected data does not include the
Master Boot Record or Pre-authentication area of the drive – areas of
the drive that are necessarily unencrypted.
Submask
A submask is a bit string that can be generated and stored in a number
of ways.
1.3 Implementation
Full Drive Encryption solutions vary with implementation and vendor combinations.
Therefore, vendors will evaluate products that provide both components of the Full Disk
Encryption Solution (AA and EE) against both cPPs – could be done in a single evaluation
with one ST. A vendor that provides a single component of a FDE solution would only evaluate
against the applicable cPP. The FDEcPP is divided into two documents to allow labs to
independently evaluate solutions tailored to one cPP or the other. When a customer acquires
an FDE solution, they will either obtain a single vendor product that meets the AA + EEcPPs
or two products, one of which meets the AA and the other of which meets the EEcPPs.
The table below illustrates a few examples for certification
A single vendor’s combination of hardware (e.g. hardware encryption engine,
cryptographic co-processor) and software
1.4 TOE Overview
The Target of Evaluation (TOE) for this cPP (Authorization Acquisition) may be either a Host software solution that manages a HW Encryption Engine (e.g. a SED) or as part of a combined evaluation of this cPP and the Encryption Engine cPP for a vendor that is providing a solution that includes both components.
The following sections provide an overview of the functionality of the FDEAA as well as the security capabilities.
1.4.1 Authorization Acquisition Introduction
The Authorization Acquisition sends a Border Encryption Value (BEV), which could be a Key Encryption Key (KEK), a Key Releasing Key (KRK), or some other type of key to the Encryption Engine. The EE does not have to use this value directly as the key to decrypt or release the DEK. It may use it as part of a scheme that uses other intermediate keys to eventually protect the DEK. A KEK wraps other keys, notably the DEK or other intermediary keys which chain to the DEK. Key Releasing Keys (KRKs) authorize the EE to release either the DEK or other intermediary keys which chain to the DEK. Figure 2 illustrates the components within AA and its relationship with EE.
Figure 2:
Authorization Acquisition Details
Authorization factors may be unique to individual users or may be used by a group of individuals. In other words, the EE requires authorization factors from the AA to establish that the possessor of the authorization factor belongs to the community of users authorized to access information stored on the storage device (and does not require specific user authorization). Examples of authorization factors include, but are not limited to, passwords, passphrases, or randomly generated values stored on USB tokens or a pin to release a key on hardware storage media such as a Trusted Platform Module (TPM).
The AA collects authorization factors which the EE uses to access data on the storage device and perform a variety of management functions. Depending on the type of authorization factor, the AA may condition them further. For example, it may apply an approved password-based key derivation function (e.g. PBKDF2) on passwords. An external token containing a randomly generated value of sufficient strength may require no further conditioning on the authorization factors. The AA may then combine one or more authorization factors in such a way that maintains the strength of both factors.
The AA serves as the main management interface to the EE. However, the EE may also offer management functionality. The requirements in the EEcPP address how the EE should handle these features. The management functionality may include the ability to send commands to the EE such as changing a DEK, setting up new users, managing KEKs and other intermediate keys, and performing a key sanitization (e.g. overwrite of the DEK). It may also forward commands that partition the drive for use by multiple users. However, this document defers the management of partitions and assumes that administrators will only provision and manage the data on whole drives.
1.4.3 Interface/Boundary
The interface and boundary between the AA and the EE will vary based on the implementation. If one vendor provides the entire FDE solution, then it may choose to not implement an interface between the AA and EE components. If a vendor provides a solution for one of the components, then the assumptions below state that the channel between the two components is sufficiently secure. Although standards and specifications exist for the interface between AA and EE components, the cPP does not require vendors to follow the standards in this version.
1.5 Compliant Targets of Evaluation
1.5.1 TOE Boundary
The environment in which the AA functions may differ depending on the boot stage of the platform in which it operates, see Figure 3. Depending on the solution’s architecture, aspects of provisioning, initialization, and authorization may be performed in the Pre-Boot environment, while encryption, decryption and management functionality are likely performed in the Operating System environment. In non-software solutions, encryption/decryption starts in Pre30 OS environment and continues into OS present environment.
In the Operating System environment, the Authorization Acquisition has the full range of services available from the operating system (OS), including hardware drivers, cryptographic libraries, and perhaps other services external to the TOE.
The Pre-Boot environment is much more constrained with limited capabilities. This environment turns on the minimum number of peripherals and loads only those drivers necessary to bring the platform from a cold start to executing a fully functional operating system with running applications.
The AATOE may include or leverage features and functions within the operational environment.
Figure 3:
Operational Environment
1.6 Use Cases
The use case for a product conforming to the FDEcPPs is to protect data at rest on a device that is lost or stolen while powered off without any prior access by an adversary. The use case where an adversary obtains a device that is in a powered state and is able to make modifications to the environment or the TOE itself (e.g., evil maid attacks) is not addressed by these cPPs (i.e., FDE-AA and FDE- EE).
The evaluation methods used for evaluating the TOE are a combination of the workunits
defined in [CEM] as well as the Evaluation Activities for ensuring that individual SFRs
and SARs have a sufficient level of supporting evidence in the Security Target and guidance
documentation and have been sufficiently tested by the laboratory as part of completing
ATE_IND.1. Any functional packages this PP claims similarly contain their own Evaluation
Activities that are used in this same manner.
CC Conformance Claims
This PP is conformant to
Part 2 (extended)
and Part 3 (conformant)
of Common Criteria CC:2022, Revision 1.
PP Claim
This PP does not claim conformance to
any Protection Profile.
The following PPs and PP-Modules are allowed to be specified in a
PP-Configuration with this PP:
PP-Module for File Encryption Enterprise Management Version 2.0
Package Claim
This PP is not conformant to any
Functional or Assurance Packages.
3 Security Problem Definition
3.1 Threats
This section provides a narrative that describes how the requirements mitigate the mapped
threats. A requirement may mitigate aspects of multiple threats. A requirement may only mitigate a threat in a limited way. Some requirements are optional, either because the TSF fully mitigates the threat without the additional requirements being claimed or because the TSF relies on its Operational Environment to provide the functionality that is described by the optional requirements.
A threat consists of a threat agent, an asset and an adverse action of that threat agent on that asset. The threat agents are the entities that put the assets at risk if an adversary obtains a lost or stolen storage device. Threats drive the functional requirements for the target of evaluation (TOE). For instance, one threat below is T.UNAUTHORIZED_DATA_ACCESS. The threat agent is the possessor (unauthorized user) of a lost or stolen storage device. The asset is the data on the storage device, while the adverse action is to attempt to obtain those data from the storage device. This threat drives the functional requirements for the storage device encryption (TOE) to authorize who can use the TOE to access the hard disk and encrypt/decrypt the data. Since possession of the KEK, DEK, intermediate keys, authorization factors, submasks, and random numbers or any other values that contribute to the creation of keys or authorization factors could allow an unauthorized user to defeat the encryption, this SPD considers key material equivalent to the data in importance and they appear among the other assets addressed below.
It is important to reemphasize at this point that this collaborative Protection Profile does not expect the product (TOE) to defend against the possessor of the lost or stolen hard disk who can introduce malicious code or exploitable hardware components into the Target of Evaluation (TOE) or the Operational Environment. It assumes that the user physically protects the TOE and that the Operational Environment provides sufficient protection against logical attacks. One specific area where a conformant TOE offers some protection is in providing updates to the TOE; other than this area, though, this cPP mandates no other countermeasures. Similarly, these requirements do not address the “lost and found” hard disk problem, where an adversary may have taken the hard disk, compromised the unencrypted portions of the boot device (e.g., MBR, boot partition), and then made it available to be recovered by the original user so that they would execute the compromised code.
T.AUTHORIZATION_GUESSING
Threat agents may exercise host software to repeatedly guess authorization factors, such as passwords and PINs. Successful guessing of the authorization factors may cause the TOE to release BEV or otherwise put it in a state in which it discloses protected data to unauthorized users.
T.KEYING_MATERIAL_COMPROMISE
Possession of any of the keys, authorization factors, submasks, and random
numbers or any other values that contribute to the creation of keys or authorization factors
could allow an unauthorized user to defeat the encryption. The cPP considers possession of
key material of equal importance to the data itself. Threat agents may look for key material
in unencrypted sectors of the storage device and on other peripherals in the operating environment
(OE), (e.g., BIOS configuration, SPI flash).
T.KEYSPACE_EXHAUST
Threat agents may perform a cryptographic exhaust against the key space. Poorly chosen encryption algorithms and parameters allow attackers to exhaust the key space through brute force and give them unauthorized access to the data.
T.UNAUTHORIZED_DATA_ACCESS
The cPP addresses the primary threat of unauthorized disclosure of protected data stored on a storage device. If an adversary obtains a lost or stolen storage device (e.g., a storage device contained in a laptop or a portable external storage device), they may attempt to connect a targeted storage device to a host of which they have complete control and have raw access to the storage device (e.g., to specified disk sectors, to specified blocks).
T.UNAUTHORIZED_UPDATE
Threat agents may attempt to perform an update of the product which compromises the security features of the TOE. Poorly chosen update protocols, signature generation and verification algorithms, and parameters may allow attackers to install software or firmware that bypasses the intended security features and provides them unauthorized access to data.
3.2 Assumptions
A.INITIAL_DRIVE_STATE
Users enable Full Drive Encryption on a newly provisioned or initialized storage device free of protected data in areas not targeted for encryption. The cPP does not intend to include requirements to find all the areas on storage devices that potentially contain protected data. In some cases, it may not be possible - for example, data contained in “bad” sectors.
While inadvertent exposure to data contained in bad sectors or un-partitioned space is unlikely, one may use forensics tools to recover data from such areas of the storage device. Consequently, the cPP assumes bad sectors, un-partitioned space, and areas that must contain unencrypted code (e.g., MBR and AA/EE pre-authentication software) contain no protected data.
A.PASSWORD_STRENGTH
Authorized administrators ensure passwords and passphrase authorization factors have sufficient strength and entropy to reflect the sensitivity of the data being protected.
A.PHYSICAL
The platform is assumed to be physically protected in its Operational Environment and not subject to physical attacks that compromise the security and/or interfere with the platform’s correct operation.
A.PLATFORM_IA
The product does not interfere with or change the normal platform identification and authentication functionality such as the operating system login. It may provide authorization factors to the operating system's login interface, but it will not change or degrade the functionality of the actual interface.
A.PLATFORM_STATE
The platform in which the storage device resides (or an external storage device is connected) is free of malware that could interfere with the correct operation of the product.
A.POWER_DOWN
The user does not leave the platform and/or storage device unattended until all volatile memory is cleared after a power-off, so memory remnant attacks are infeasible.
Authorized users do not leave the platform and/or storage device in a mode where sensitive information persists in non-volatile storage (e.g., lock screen). Users power the platform and/or storage device down or place it into a power managed state, such as a “hibernation mode”.
A.SECURE_STATE
Upon the completion of proper provisioning, the drive is only assumed secure when in a powered off state up until it is powered on and receives initial authorization.
A.SINGLE_USE_ET
External tokens that contain authorization factors are used for no other purpose than to store the external token authorization factors.
A.STRONG_CRYPTO
All cryptography implemented in the Operational Environment and used by the product meets the requirements listed in the cPP. This includes generation of external token authorization factors by a RBG.
A.TRAINED_USER
Authorized users follow all provided user guidance, including keeping passwords and passphrases and external tokens securely stored separately from the storage device and/or platform.
A.TRUSTED_CHANNEL
Communication among and between product components (e.g., AA and EE) is sufficiently protected to prevent information disclosure. In cases in which a single product fulfils both cPPs, then the communication between the components does not extend beyond the boundary of the TOE (e.g., communication path is within the TOE boundary). In cases in which independent products satisfy the requirements of the AA and EE, the physically close proximity of the two products during their operation means that the threat agent has very little opportunity to interpose itself in the channel between the two without the user noticing and taking appropriate actions.
3.3 Organizational Security Policies
This document does not define any additional OSPs.
4 Security Objectives
4.1 Security Objectives for the Operational Environment
The Operational Environment of the TOE implements technical and procedural measures to assist the TOE in correctly providing its security functionality. This part wise solution forms the security objectives for the Operational Environment and consists of a set of statements describing the goals that the Operational Environment should achieve.
OE.INITIAL_DRIVE_STATE
The OE provides a newly provisioned or initialized storage device free of protected data in areas not targeted for encryption.
Rationale: Since the cPP requires all protected data to encrypted A.INITIAL_DRIVE_STATE assumes that the initial state of the device targeted for FDE is free of protected data in those areas of the drive where encryption will not be invoked (e.g., MBR and AA/EE pre-authentication software). Given this known start state, the product (once installed and operational) ensures partitions of logical blocks of user accessible data is protected.
OE.PASSPHRASE_STRENGTH
An authorized administrator will be responsible for ensuring that the passphrase authorization factor conforms to guidance from the Enterprise using the TOE.
Rationale: Users are properly trained [A.TRAINED_USER] to create authorization
factors that conform to administrative guidance.
OE.PHYSICAL
The Operational Environment will provide a secure physical computing space such than an adversary is not able to make modifications to the environment or to the TOE itself.
Rationale: As stated in section 1.6, the use case for this cPP is to protect data at rest on a device where the adversary receives it in a powered off state and has no prior access.
OE.PLATFORM_IA
The Operational Environment will provide individual user identification and authentication mechanisms that operate independently of the authorization factors used by the TOE.
Rationale: While the product may provide authorization factors to the Operating system's login interface, it must not change or degrade the functionality of the actual interface. A.PLATFORM_I&A requires that the product not interfere or change the normal platform I&A functionality.
OE.PLATFORM_STATE
The platform in which the storage device resides (or an external
storage device is connected) is free of malware that could interfere with the correct operation
of the product.
Rationale: A platform free of malware [A.PLATFORM_STATE] prevents an attack vector that could potentially interfere with the correct operation of the product.
OE.POWER_DOWN
Volatile memory is cleared after power-off so memory remnant attacks are infeasible.
Rationale: Users are properly trained [A.TRAINED_USER] to not leave the storage device unattended until powered down or placed in a managed power state such as “hibernation mode”. A.POWER_DOWN stipulates that such memory remnant attacks are infeasible given the device is in a powered-down or “hibernation mode” state.
OE.SINGLE_USE_ET
External tokens that contain authorization factors will be used for no
other purpose than to store the external token authorization factor.
Rationale: Users are properly trained [A.TRAINED_USER] to use external token authorization factors as intended and for no other purpose.
OE.STRONG_ENVIRONMENT_CRYPTO
The Operating Environment will provide a cryptographic function capability that is commensurate with the requirements and capabilities of the TOE and Appendix A.
Rationale: All cryptography implemented in the Operational Environment and used by
the product meets the requirements listed in this cPP [A.STRONG_CRYPTO].
OE.TRAINED_USERS
Authorized users will be properly trained and follow all guidance for securing the TOE and authorization factors.
Rationale: Users are properly trained [A.TRAINED_USER] to create authorization factors that conform to guidance, not store external token authorization factors with the device, and power down the TOE when required (OE.PLATFORM_STATE) The platform in which the storage device resides (or an external storage device is connected) is free of malware that could interfere with the correct operation of the product.
A platform free of malware [A.PLATFORM_STATE] prevents an attack vector that could potentially interfere with the correct operation of the product.
OE.TRUSTED_CHANNEL
Communication among and between product components (i.e., AA and EE) is sufficiently protected to prevent information disclosure.
Rationale: In situations where there is an opportunity for an adversary to interpose
themselves in the channel between the AA and the EE a trusted channel must be established to prevent exploitation. [A.TRUSTED_CHANNEL] assumes the existence of a trusted channel between the AA and EE, except for when the boundary is within and does not breach the TOE or is in such close proximity that a breach is not possible without detection.
4.2 Security Objectives Rationale
This section describes how the assumptions and organizational
security policies map to operational environment security objectives.
This chapter describes the security requirements which have to be fulfilled by the product under evaluation. Those requirements comprise functional components from Part 2 and assurance components from Part 3 of
[CC].
The following conventions are used for the completion of operations:
Refinement operation (denoted by bold text or strikethrough
text): Is used to add details to a requirement or to remove part of the requirement that is made irrelevant
through the completion of another operation, and thus further restricts a requirement.
Selection (denoted by italicized text): Is used to select one or more options
provided by the [CC] in stating a requirement.
Assignment operation (denoted by italicized text): Is used to assign a
specific value to an unspecified parameter, such as the length of a password. Showing the
value in square brackets indicates assignment.
Iteration operation: Is indicated by appending the SFR name with a slash and unique identifier
suggesting the purpose of the operation, e.g. "/EXAMPLE1."
5.1 Security Functional Requirements
The individual security functional requirements are specified in the sections below.
The TSF shall accept the following authorization factors: [selection:
a submask derived from a password authorization factor conditioned as defined in FCS_PCC_EXT.1,
an external smart card factor that is protecting a submask that is
[selection: generated by the TOE (using the RBG as specified in FCS_RBG.1), generated by the Host Platform]
protected using [selection:
ECC schemes using "NIST curves" of [selection: P-256, P-384, P-521]
]
with user presence proved by presentation of the smart card and [selection: none, an OE defined PIN, a configurable PIN],
an external USB token factor that is at least the same security strength as the BEV, and is protecting a submask generated by the TOE, using the RBG as specified in FCS_RBG.1,
an external USB token factor that is at least the same security strength as the BEV, and is protecting a submask generated by the Host Platform
]
Application
Note:
This requirement specifies what authorization factors
the TOE accepts from the user. A password entered by the user is one authorization factor that the TOE must be able to condition, as specified in FCS_PCC_EXT.1. Another option is a smart card authorization factor, with the differentiating feature being how the value is generated – either by the TOE’s RBG or by the platform. An external USB token may also be used, with the submask value generated either by the TOE’s RBG or by the platform.
The TOE may accept any number of authorization factors, and these are categorized as “submasks”. The ST author selects the authorization factors they support, and there may be multiple methods for a selection.
Use of multiple authorization factors is preferable; if more than one authorization factor is used, the submasks produced must be combined using FCS_SMC_EXT.1 specified in Appendix A.
The TOE’s use of symmetric key generation (i.e., deterministic random bit generation) and symmetric encryption determines whether the selection-based requirements FCS_CKM.1/SKG, FCS_RBG.1, and FCS_COP.1/SKC are claimed.
The evaluator shall first examine the TSS to ensure that the authorization factors
specified in the ST are described. For password-based factors the examination of the
TSS section is performed as part of FCS_PCC_EXT.1 Evaluation Activities. Additionally in this case, the evaluator shall verify that the operational guidance
discusses the characteristics of external authorization factors (e.g., how the
authorization factor must be generated; formats or standards that the authorization
factor must meet) that are able to be used by the TOE.
If other authorization factors are specified, then for each factor, the TSS specifies how
the factors are input into the TOE.
Guidance
The evaluator shall verify that the AGD guidance includes instructions for all of the
authorization factors. The AGD will discuss the characteristics of external
authorization factors (e.g., how the authorization factor is generated; formats or
standards that the authorization factor must meet, configuration of the TPM device
used) that are able to be used by the TOE.
The evaluator shall examine the Key Management Description to confirm that the initial authorization factors (submasks) directly contribute to the unwrapping of the BEV.
The evaluator shall verify the KMD describes how a submask is produced from the authorization factor (including any associated standards to which this process might conform), and verification is performed to ensure the length of the submask meets the required size (as specified in this requirement).
Tests
The password authorization factor is tested in FCS_PCC_EXT.1.
The evaluator shall also perform the following tests:
Test FCS_AFA_EXT.1:1:
(conditional): If there is more than one authorization factor, ensure that failure to supply a required authorization factor does not result in access to the decrypted plaintext data.
FCS_AFA_EXT.2 Timing of Authorization Factor Acquisition
The TSF shall reacquire the authorization factors specified in FCS_AFA_EXT.1
upon transition from any compliant power saving state specified in FPT_PWR_EXT.1 prior to permitting access to plaintext data.
Application
Note:
This should be accomplished by clearing keys that are no longer needed so that keys must be derived or decrypted again.
The evaluator shall examine the TSS for a description of authorization factors and which of the factors are used to gain access to user data after the TOE entered a compliant power saving state. The TSS is inspected to ensure it describes that each authorization factor satisfies the requirements of FCS_AFA_EXT.1.1.
Guidance
The evaluator shall examine the guidance documentation for a description of authorization factors used to access plaintext data when resuming from a compliant power saving state.
The TSF shall destroy [all keys and key material] when [no longer
needed].
Application
Note:
Keys, including intermediate keys and key material that are no longer needed are destroyed by
using an approved method, FCS_CKM.6.
Examples of keys are intermediate keys, submasks, and BEV. There may be instances where keys or key material that are
contained in persistent storage are no longer needed and require destruction. Based on their implementation, vendors
will explain when certain keys are no longer needed. There are multiple situations in which key material is no longer
necessary, for example, a wrapped key may need to be destroyed when a password is changed. However, there are
instances when keys are allowed to remain in memory, for example, a device identification key. If a PIN was used for
a smart card, the TSF should ensure that the PIN was properly destroyed.
The TSF shall destroy cryptographic keys and keying material specified by
FCS_CKM.6.1 in accordance with a specified cryptographic key destruction method [selection:
For volatile memory, the destruction shall be executed by a [selection:
[assignment:
some value that does not contain any CSP]
]
removal of power to the memory,
destruction of reference to the key directly followed by a request for garbage collection
]
For non-volatile storage that consists of the invocation of an interface provided by the underlying platform that [selection:
logically addresses the storage location of the key and performs a [selection: single, [assignment:
ST author defined multi-pass]] overwrite consisting of [selection:
The interface referenced in the requirement could take different forms, the most likely of which is an application programming interface to an OS kernel. There may be various levels of abstraction visible. For instance, in a given implementation the application may have access to the file system details and may be able to logically address specific memory locations. In another implementation the application may simply have a handle to a resource and can only ask the platform to delete the resource. The level of detail to which the TOE has access will be reflected in the TSS section of the ST.
Several selections allow assignment of a ‘value that does not contain any CSP’. This means that the TOE uses some other specified data not drawn from an RBG meeting FCS_RBG.1 requirements, and not being any of the particular values listed as other selection options. The point of the phrase ‘does not contain any CSP’ is to ensure that the overwritten data is carefully selected, and not taken from a general ‘pool’ that might contain current or residual data that itself requires confidentiality protection.
The evaluator shall verify the TSS provides a high level description of what it means for keys and key material to be no longer needed and when then should be expected to be destroyed.
Guidance
There are no AGD evaluation activities for this SFR.
The evaluator shall verify the KMD includes a description of the areas where keys and
key material reside and when the keys and key material are no longer needed.
The evaluator shall verify the KMD includes a key lifecycle, that includes a description
where key material reside, how the key material is used, how it is determined that keys
and key material are no longer needed, and how the material is destroyed once it is not
needed and that the documentation in the KMD follows FCS_CKM.4(a) for the
destruction.
Tests
There are no test evaluation activities for this SFR.
The evaluator examines the TSS to ensure it describes how the keys are managed in
volatile memory. This description includes details of how each identified key is
introduced into volatile memory (e.g. by derivation from user input, or by unwrapping
a wrapped key stored in non-volatile memory) and how they are overwritten.
The evaluator shall check to ensure the TSS lists each type of key that is stored in
non-volatile memory, and identifies how the TOE interacts with the underlying
platform to manage keys (e.g., store, retrieve, destroy). The description includes details
on the method of how the TOE interacts with the platform, including an identification
and description of the interfaces it uses to manage keys (e.g., file system APIs, platform
key store APIs).
The evaluator examines the interface description for each different media type to ensure
that the interface supports the selections and description in the TSS.
The evaluator shall check that the TSS identifies any configurations or circumstances
that may not strictly conform to the key destruction requirement. If the ST makes use
of the open assignment and fills in the type of pattern that is used, the evaluator
examines the TSS to ensure it describes how that pattern is obtained and used. The
evaluator shall verify that the pattern does not contain any CSPs.
Guidance
There are a variety of concerns that may prevent or delay key destruction in some cases. The evaluator shall check that the guidance documentation identifies configurations or
circumstances that may not strictly conform to the key destruction requirement, and
that this description is consistent with the relevant parts of the TSS and any other
relevant Required Supplementary Information. The evaluator shall check that the
guidance documentation provides guidance on situations where key destruction may
be delayed at the physical layer.
For example, when the TOE does not have full access to the physical memory, it is
possible that the storage may be implementing wear-leveling and garbage collection. This may create additional copies of the key that are logically inaccessible but persist
physically. In this case, it is assumed the drive supports the TRIM command and
implements garbage collection to destroy these persistent copies when not actively
engaged in other tasks.
Drive vendors implement garbage collection in a variety of different ways, as such
there is a variable amount of time until data is truly removed from these solutions. There is a risk that data may persist for a longer amount of time if it is contained in a
block with other data not ready for erasure. It is assumed the operating system and file
system of the OE support TRIM, instructing the non-volatile memory to erase copies
via garbage collection upon their deletion.
It is assumed that if a RAID array is being used, only set-ups that support TRIM are
utilized. It is assumed if the drive is connected via PCI-Express, the operating system
supports TRIM over that channel. It is assumed the drive is healthy and contains minimal corrupted data and will be end of life before a significant amount of damage
to drive health occurs, it is assumed there is a risk small amounts of potentially
recoverable data may remain in damaged areas of the drive.
Finally, it is assumed the keys are not stored using a method that would be inaccessible
to TRIM, such as being contained in a file less than 982 bytes which would be
completely contained in the master file table.
Test FCS_CKM.6.2:1:
Applied to each key held as plaintext in volatile memory and subject to
destruction by overwrite by the TOE (whether or not the plaintext value is subsequently
encrypted for storage in volatile or non-volatile memory). In the case where the only
selection made for the destruction method key was removal of power, then this test is
unnecessary. The evaluator shall:
Record the value of the key in the TOE subject to clearing.
Cause the TOE to perform a normal cryptographic processing with the key
from Step #1.
Cause the TOE to dump the entire memory of the TOE into a binary file.
Search the content of the binary file created in Step #5 for instances of the
known key value from Step #1.
Break the key value from Step #1 into 3 similar sized pieces and perform a
search using each piece.
Steps 1-6 ensure that the complete key does not exist anywhere in volatile memory. If
a copy is found, then the test fails.
Step 7 ensures that partial key fragments do not remain in memory. If a fragment is
found, there is a minuscule chance that it is not within the context of a key (e.g., some
random bits that happen to match). If this is the case the test should be repeated with a
different key in Step #1. If a fragment is found the test fails.
The following tests apply only for the selection of “logically addresses the storage location…”, since the TOE in this instance has more
visibility into what is happening within the underlying platform (e.g., a logical view of
the media). For the selection of “instructs the underlying platform…”, the TOE has no visibility into the inner workings and
completely relies on the underlying platform, so there is no reason to test the TOE
beyond test 1.
For the selection of “logically addresses the storage location…”, the following tests are used to determine the TOE is able to request
the platform to overwrite the key with a TOE supplied pattern.
Test FCS_CKM.6.2:2:
Applied to each key held in non-volatile memory and subject to destruction by overwrite by the TOE. The evaluator shall use a tool that provides a logical view of the media (e.g., MBR file system):
Record the value of the key in the TOE subject to clearing.
Cause the TOE to perform a normal cryptographic processing with the key from Step #1.
Search the logical view that the key was stored in for instances of the known
key value from Step #1. If a copy is found, then the test fails.
Break the key value from Step #1 into 3 similar sized pieces and perform a
search using each piece. If a fragment is found then the test is repeated (as
described for Use Case 1 test 1 above), and if a fragment is found in the
repeated test then the test fails.
Test FCS_CKM.6.2:3:
Applied to each key held as non-volatile memory and subject to destruction by overwrite by the TOE. The evaluator shall use a tool that provides a logical view of the media:
Record the logical storage location of the key in the TOE subject to clearing
Cause the TOE to perform a normal cryptographic processing with the key
from Step #1.
The TSF shall [selection: instruct the operational environment to clear, erase] [cryptographic keys and key material from volatile
memory] when [transitioning to a compliant power saving state as
defined by FPT_PWR_EXT.1] that meets the following: [a key
destruction method specified in FCS_CKM.6].
Application
Note:
In some cases, erasure of keys from volatile memory is
only supported by the operational environment, in which case the operational
environment must expose a well-documented mechanism or interface to invoke the memory clearing operation.
The TSF shall destroy [all key material, BEV, and authentication factors
stored in plaintext] when [transitioning to a compliant power saving
state as defined by FPT_PWR_EXT.1].
Application
Note:
The TOE may end up in a non-compliant power saving
state indistinguishable from a compliant power state (e.g. as result of sudden or
unexpected power loss). For those scenarios, the TOE or the operational
environment guidance documentation must provide procedures to support destruction of key material (e.g., automated reboot with memory clearing in early stages of the system’s power-on sequence).
The evaluator shall verify the TSS provides a high level description of how keys stored in volatile memory are destroyed. The valuator to verify that TSS outlines:
if and when the TSF or the Operational Environment is used to destroy keys from volatile memory;
if and how memory locations for (temporary) keys are tracked;
details of the interface used for key erasure when relying on the OE for memory clearing.
Guidance
The evaluator shall check the guidance documentation if the TOE depends on the
Operational Environment for memory clearing and how that is achieved.
The evaluator shall verify the TSS provides a description of what keys and key material
are destroyed when entering any compliant power saving state.
Guidance
The evaluator shall validate that guidance documentation contains clear warnings and
information on conditions in which the TOE may end up in a non-compliant power
saving state indistinguishable from a compliant power saving state. In that case it must
contain mitigation instructions on what to do in such scenarios.
The evaluator shall verify the KMD includes a description of the areas where keys and
key material reside.
The evaluator shall verify the KMD includes a key lifecycle that includes a description
where key material resides, how the key material is used, and how the material is
destroyed once it is not needed and that the documentation in the KMD follows
FCS_CKM.6 for the destruction.
Tests
There are no test evaluation activities for this SFR.
The TSF shall perform [cryptographic hashing services] in accordance with a specified cryptographic algorithm [selection: SHA-256, SHA-384, SHA-512] and cryptographic key sizes [assignment:
cryptographic key sizes] that meet the following: [ISO/IEC 10118-3:2004]
Application
Note:
The selection should be consistent with the overall strength of the algorithm used for FCS_COP.1/SigVer and quantum resistant recommendations. For example,
SHA-256 should be chosen for 2048-bit RSA or ECC with P-256, SHA-384 should be chosen for 3072-bit RSA, 4096-bit RSA, or ECC with P-384, and SHA-512 should
be chosen for ECC with P-521. The selection of the standard is made based on the algorithms selected.
This SFR is required for the use of verifying digital signatures for trusted updates (FPT_TUD_EXT.1). It may also be used when the TSF performs validation
of a submask, intermediate key, or BEV by using a hash operation (FCS_VAL_EXT.1).
The evaluator shall check that the association of the hash function with other TSF
cryptographic functions (for example, the digital signature verification function) is
documented in the TSS.
Guidance
The evaluator checks the operational guidance documents to determine that any system
configuration necessary to enable required hash size functionality is provided.
There are no KMD evaluation activities for this SFR.
Tests
The TSF hashing functions can be implemented in one of two modes. The first mode
is the byte-oriented mode. In this mode the TSF only hashes messages that are an
integral number of bytes in length; i.e., the length (in bits) of the message to be hashed
is divisible by 8. The second mode is the bit-oriented mode. In this mode the TSF
hashes messages of arbitrary length. As there are different tests for each mode, an
indication is given in the following sections for the bit-oriented vs. the byte-oriented
test mode.
The evaluator shall perform all of the following tests for each hash algorithm implemented by the TSF and used to satisfy the requirements of this cPP.
Short Messages Test Bit-oriented Mode
The evaluators devise an input set consisting of m+1 messages, where m is the block
length of the hash algorithm. The length of the messages range sequentially from 0 to
m bits. The message text shall be pseudorandomly generated. The evaluators compute
the message digest for each of the messages and ensure that the correct result is
produced when the messages are provided to the TSF.
Short Messages Test Byte-oriented Mode
The evaluators devise an input set consisting of m/8+1 messages, where m is the block
length of the hash algorithm. The length of the messages range sequentially from 0 to
m/8 bytes, with each message being an integral number of bytes. The message text shall
be pseudorandomly generated. The evaluators compute the message digest for each of
the messages and ensure that the correct result is produced when the messages are
provided to the TSF.
Selected Long Messages Test Bit-oriented Mode
The evaluators devise an input set consisting of m messages, where m is the block
length of the hash algorithm. For SHA-256, the length of the i-th message is 512 +
99*i, where 1 ≤ i ≤ m. For SHA-384 and SHA-512, the length of the i-th message is
1024 + 99*i, where 1 ≤ i ≤ m. The message text shall be pseudorandomly generated. The evaluators compute the message digest for each of the messages and ensure that
the correct result is produced when the messages are provided to the TSF.
Selected Long Messages Test Byte-oriented Mode
The evaluators devise an input set consisting of m/8 messages, where m is the block
length of the hash algorithm. For SHA-256, the length of the i-th message is 512 +
8*99*i, where 1 ≤ i ≤ m/8. For SHA-384 and SHA-512, the length of the i-th message
is 1024 + 8*99*i, where 1 ≤ i ≤ m/8. The message text shall be pseudorandomly
generated. The evaluators compute the message digest for each of the messages and
ensure that the correct result is produced when the messages are provided to the TSF.
Pseudorandomly Generated Messages Test
This test is for byte-oriented implementations only. The evaluators randomly generate
a seed that is n bits long, where n is the length of the message digest produced by the
hash function to be tested. The evaluators then formulate a set of 100 messages and
associated digests by following the algorithm provided in Figure 1 of the NIST Secure
Hash Algorithm Validation System (SHAVS)
(https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Algorithm-ValidationProgram/documents/shs/SHAVS.pdf). The evaluators then ensure that the correct
result is produced when the messages are provided to the TSF.
The TSF shall perform [cryptographic signature services
(verification)] in accordance with a specified cryptographic
algorithm [selection:
RSA Digital Signature Algorithm with a key size (modulus) of [selection: 2048-bit, 3072-bit, 4096-bit]
Elliptic Curve Digital Signature Algorithm with a key size of [256 bits or greater]
]
that meet the following: [selection:
FIPS PUB 186-4, “Digital Signature Standard (DSS)”, Section 5.5, using PKCS #1 v2.1 Signature Schemes RSASSA-PSS and/or RSASSA-PKCS1-v1_5; ISO/IEC 9796-2, Digital signature scheme 2 or Digital Signature scheme 3, for RSA schemes
FIPS PUB 186-4, “Digital Signature Standard (DSS)”, Section 6 and Appendix D, Implementing “NIST curves” [selection: P-256, P-384, P-521] ISO/IEC 14888-3, Section 6.4, for ECDSA schemes
Application
Note:
The selection should be consistent with the overall strength of the algorithm used for FCS_COP.1/SigVer and quantum resistant recommendations. For example,
SHA-256 should be chosen for 2048-bit RSA or ECC with P-256, SHA-384 should be chosen for 3072-bit RSA, 4096-bit RSA, or ECC with P-384, and SHA-512 should
be chosen for ECC with P9 521. The selection of the standard is made based on the algorithms selected.
This SFR is mandatory for its use in verification of digital signatures for TOE updates. It may also be used when the TSF performs validation of a submask,
intermediate key, or BEV by using a digital signature operation (FCS_VAL_EXT.1).
This requirement is used to verify digital signatures attached to updates from the TOE
manufacturer before installing those updates on the TOE. Because this component is to
be used in the update function, additional Evaluation Activities to those listed below
are covered in other evaluation activities sections in this document. The following
activities deal only with the implementation for the digital signature algorithm; the
evaluator performs the testing appropriate for the algorithms selected in the
component.
Hash functions and/or random number generation required by these algorithms must
be specified in the ST; therefore the Evaluation Activities associated with those
functions are contained in the associated Cryptographic Hashing and Random Bit
Generation sections. Additionally, the only function required by the TOE is the
verification of digital signatures. If the TOE generates digital signatures to support the
implementation of any functionality required by this cPP, then the applicable
evaluation and validation scheme must be consulted to determine the required
evaluation activities.
The evaluator shall check the TSS to ensure that it describes the overall flow of the
signature verification. This should at least include identification of the format and
general location (e.g., "firmware on the hard drive device" rather than “memory
location 0x00007A4B") of the data to be used in verifying the digital signature; how
the data received from the operational environment are brought on to the device; and
any processing that is performed that is not part of the digital signature algorithm (for
instance, checking of certificate revocation lists).
Guidance
There are no AGD evaluation activities for this SFR.
There are no KMD evaluation activities for this SFR.
Tests
Each section below contains the tests the evaluators must perform for each type of
digital signature scheme. Based on the assignments and selections in the requirement,
the evaluators choose the specific activities that correspond to those selections.
It should be noted that for the schemes given below, there are no key generation/domain
parameter generation testing requirements. This is because it is not anticipated that this
functionality would be needed in the end device, since the functionality is limited to
checking digital signatures in delivered updates. This means that the domain
parameters should have already been generated and encapsulated in the hard drive
firmware or on-board non-volatile storage. If key generation/domain parameter
generation is required, the evaluation and validation scheme must be consulted to
ensure the correct specification of the required evaluation activities and any additional
components.
The following tests are conditional based upon the selections made within the SFR.
The following tests may require the developer to provide access to a test platform that
provides the evaluator with tools that are typically not found on factory products.
For each supported NIST curve (i.e., P-256, P-384 and P-521) and SHA function pair,
the evaluator shall generate a set of 10 1024-bit message, public key and signature
tuples and modify one of the values (message, public key or signature) in five of the 10
tuples. The evaluator shall obtain in response a set of 10 PASS/FAIL values.
The evaluator shall perform the Signature Verification test to verify the ability of the
TOE to recognize another party’s authentic and unauthentic signatures. The evaluator
shall inject errors into the test vectors produced during the Signature Verification Test
by introducing errors in some of the public keys e, messages, IR format, and/or
signatures. The TOE attempts to verify the signatures and returns success or failure.
The evaluator shall use these test vectors to emulate the signature verification test using
the corresponding parameters and verify that the TOE detects these errors.
]
while maintaining an effective strength of
[selection: 128 bits, 256 bits] for symmetric keys and an effective strength of
[selection: not applicable, 112 bits, 128 bits, 192 bits, 256 bits] for asymmetric keys.
The TSF shall provide at least a
[selection: 128 bits, 256 bits] BEV to [assignment:
one or more external entities]
[selection:
after the TSF has successfully performed the validation process as specified in FCS_VAL_EXT.1
without validation taking place
]
Application
Note:
Key Chaining is the method of using multiple layers of encryption keys to ultimately secure the BEV. The number of intermediate keys will vary – from one
(e.g., taking the conditioned password authorization factor and directly using it as the BEV) to many. This applies to all keys that contribute to the
ultimate wrapping or derivation of the BEV; including those in areas of protected storage (e.g. TPM stored keys, comparison values).
Multiple key chains to the BEV are allowed, as long as all chains meet the key chain requirement.
The BEV is considered to be equivalent to keying material and therefore additional checksums or similar values are not the BEV, even if they are sent with
the BEV.
Once the ST author has selected a method to create the chain (either by deriving keys or unwrapping them or encrypting keys or using RSA Key Transport), they
pull the appropriate requirement out of Appendix B. It is allowable for an implementation to use any or all methods.
For FCS_KYC_EXT.1.2, the validation process is defined in FCS_VAL_EXT.1, Appendix B. If that selection is made by the ST author, then FCS_VAL_EXT.1 is included
in the body of the ST.
The method the TOE uses to chain keys and manage/protect them is described in the Key Management Description; see Appendix E for more information.
The evaluator shall verify the TSS contains a high-level description of the BEV sizes– that it supports BEV outputs of no fewer 128 bits for products that support only AES128, and no fewer than 256 bits for products that support AES-256.
Guidance
There are no AGD evaluation activities for this SFR.
The evaluator shall examine the KMD describes a high level description of the key hierarchy for all authorizations methods selected in FCS_AFA_EXT.1 that are used to protect the BEV. The evaluator shall examine the KMD to ensure it describes the key chain in detail. The description of the key chain shall be reviewed to ensure it maintains a chain of keys using key wrap or key derivation methods that meet FCS_COP.1/KeyWrap and FCS_KDF_EXT.1.
The evaluator shall examine the KMD to ensure that it describes how the key chain
process functions, such that it does not expose any material that might compromise any
key in the chain. (e.g. using a key directly as a compare value against a TPM) This
description must include a diagram illustrating the key hierarchy implemented and
detail where all keys and keying material is stored or what it is derived from. The
evaluator shall examine the key hierarchy to ensure that at no point the chain could be
broken without a cryptographic exhaust or the initial authorization value and the
effective strength of the BEV is maintained throughout the key chain.
The evaluator shall verify the KMD includes a description of the strength of keys
throughout the key chain.
Tests
There are no test evaluation activities for this SFR.
FCS_SNI_EXT.1 Cryptographic Operation (Salt, Nonce, and Initialization Vector Generation)
Application
Note:
This requirement covers several important factors – the salt must be random, but the nonces only have to be unique. FCS_SNI_EXT.1.3 specifies how the IV should
be handled for each encryption mode. CBC, XTS, and GCM are allowed for AES encryption of the data. AES-CCM is an allowed mode for Key Wrapping.
If the TSF uses salts in support of cryptographic operations, and these salts are generated by the TSF, then FCS_CKM.1/SKG and FCS_RBG.1 must be claimed.
If salts are used, the evaluator shall ensure the TSS describes how salts are generated. The evaluator shall confirm that the salt is generated using an RBG described in FCS_RBG.1 or by the Operational Environment. If external function is used for this purpose, the TSS should include the specific API that is called with inputs.
If IVs or nonces are used, the evaluator shall ensure the TSS describes how nonces are created uniquely and how IVs and tweaks are handled (based on the AES mode). The evaluator shall confirm that the nonces are unique and the IVs and tweaks meet the stated requirements.
Guidance
There are no AGD evaluation activities for this SFR.
The TSF shall restrict the ability to [modify the behaviour of] the functions [use of compliant power saving state] to [authorized users].
Application
Note:
“Modify the behaviour of” refers to any change in how or when a compliant power state may occur. Only privileged users are allowed to enable or disable compliant power saving states via modification of “use of compliant power saving state” function.
If support for compliant power saving states are claimed in the ST, the evaluator shall
ensure the TSS describes how these are managed and shall ensure that TSS describes
how only privileged users (administrators) are allowed to manage the states.
Guidance
The evaluator to check if guidance documentation describes which authorization
factors are required to change compliant power saving state behavior and properties.
There are no KMD evaluation activities for this SFR.
Tests
The evaluator shall perform the following tests:
Test FMT_MOF.1:1:
(conditional): If the product supports changes to compliant power saving
states, the evaluator shall present a privileged authorization credential to the TSF and validates that changes to compliant power saving state behavior and properties are
allowed.
Test FMT_MOF.1:2:
(conditional): If the product supports changes to compliant power
saving states, the evaluator shall present a non-privileged authorization credential to the TSF and validates that changes to compliant power saving state behavior are not allowed.
[selection: no other functions, specify the power saving state properties, define the allowable power saving states, generate authorization factors using the TSFRBG, configure authorization factors, configure cryptographic functionality, disable key recovery functionality, securely update the public key needed for trusted update, configure the number of failed validation attempts required to trigger corrective behavior, configure the corrective behavior to issue in the event of an excessive number of failed validation attempts, [assignment:
other management functions provided by the TSF]]]
Application
Note:
The intent of this requirement is to express the management capabilities that the TOE possesses. This means that the TOE must be able to perform the listed functions. “Configure cryptographic functionality” could include key management functions; for example, the BEV will be wrapped or encrypted, and the EE will need to unwrap or decrypt the BEV. In item e, if no other management functions are provided (or claimed), then “no other functions” should be selected
Changing the DEK would require the data to be re-encrypted with the new DEK, but allows the user the ability to generate new DEKs.
For the purposes of this document, key sanitization means to destroy the DEK, using one of the approved destruction methods. In some implementations, changing the DEK could be the same functionality as cryptographically erasing the DEK.
If item a) is selected in FMT_SMF.1.1: The evaluator shall ensure the TSS describes
how the TOE sends the request to the EE to change the DEK.
If item b) is selected in FMT_SMF.1.1: The evaluator shall ensure the TSS describes
how the TOE sends the request to the EE to cryptographically erase the DEK.
If item c) is selected in FMT_SMF.1.1: The evaluator shall ensure the TSS describes
the methods by which users may change the set of all authorization factor values
supported.
If item d) is selected in FMT_SMF.1.1: The evaluator shall ensure the TSS describes
the process to initiate TOE firmware/software updates.
If item e) is selected in FMT_SMF.1.1: If power saving states can be managed, the
evaluator shall ensure that the TSS describes how this is performed, including how the
TOE supports disabling certain power saving states if more than one are supported. If
additional management functions are claimed in the ST, the evaluator shall ensure the
TSS describes the additional functions.
Guidance
If item a) and/or b) is selected in FMT_SMF.1.1: The evaluator shall examine the
operational guidance to ensure that it describes how the functions for A and B can be
initiated by the user.
If item c) is selected in FMT_SMF.1.1: The evaluator shall examine the operational
guidance to ensure that it describes how selected authorization factor values are
changed.
If item d) is selected in FMT_SMF.1.1: The evaluator shall examine the operational
guidance to ensure that it describes how to initiate TOE firmware/software updates.
If item e) is selected in FMT_SMF.1.1: Default Authorization Factors: It may be the
case that the TOE arrives with default authorization factors in place. If it does, then the
selection in section E must be made so that there is a mechanism to change these
authorization factors. The operational guidance shall describe the method by which the
user changes these factors when they are taking ownership of the device. The TSS shall
describe the default authorization factors that exist.
Disable Key Recovery: The guidance for disabling this capability shall be described in
the AGD documentation.
Power Saving: The guidance shall describe the power saving states that are supported
by the TSF, how these states are applied, how to configure when these states are applied
(if applicable), and how to enable/disable the use of specific power saving states (if
applicable).
There are no KMD evaluation activities for this SFR
Tests
If item a) and/or b) is selected in FMT_SMF.1.1: The evaluator shall verify that the
TOE has the functionality to forward a command to the EE to change and
cryptographically erase the DEK. The actual testing of the cryptographic erase will take
place in the EE.
If item c) is selected in FMT_SMF.1.1: The evaluator shall initialize the TOE such that
it requires the user to input an authorization factor in order to access encrypted data.
Test FMT_SMF.1:1:
The evaluator shall first provision user authorization factors, and then verify
all authorization values supported allow the user access to the encrypted data. Then
the evaluator shall exercise the management functions to change a user’s
authorization factor values to a new one. Then he or she will verify that the TOE
denies access to the user’s encrypted data when he or she uses the old or original
authorization factor values to gain access.
If item d) is selected in FMT_SMF.1.1: The evaluator shall verify that the TOE has the
functionality to initiate TOE firmware/software updates.
If item e) is selected in FMT_SMF.1.1: If additional management functions are
claimed, the evaluator shall verify that the additional features function as described.
Test FMT_SMF.1:2:
(conditional): If the TOE provides default authorization values, the
evaluator shall change these values in the course of taking ownership of the device
as described in the operational guidance. The evaluator shall then confirm that the
(old) authorization values are no longer valid for data access.
Test FMT_SMF.1:3:
(conditional): If the TOE provides key recovery capability whose effects are
visible at the TOE interface, then the evaluator shall devise a test that ensures that
the key recovery capability has been or can be disabled following the guidance
provided by the vendor.
Test FMT_SMF.1:4:
(conditional): If the TOE provides the ability to configure the power saving
states that are entered by certain events, the evaluator shall devise a test that causes
the TOE to enter a specific power saving state, configure the TSF so that this
activity causes a different state to be entered, repeat the activity, and observe the
new state is entered as configured.
Test FMT_SMF.1:5:
(conditional): If the TOE provides the ability to disable the use of one or
more power saving states, the evaluator shall devise a test that enables all supported
power saving states and demonstrates that the TOE can enter into each of these
states. The evaluator shall then disable the supported power saving states one by
one, repeating the same set of actions that were performed at the start of the test,
and observe each time that when a power saving state is configured to no longer be
used, none of the behavior causes the disabled state to be entered.
only store keys in non-volatile memory when wrapped, as specified in FCS_COP.1/KeyWrap, or encrypted, as specified in FCS_COP.1/KeyEnc or FCS_COP.1/KeyEncap
only store plaintext keys that meet any one of the following criteria [selection:
the plaintext key is not part of the key chain as specified in FCS_KYC_EXT.1
the plaintext key will no longer provide access to the encrypted data after initial provisioning
the plaintext key is a key split that is combined as specified in FCS_SMC_EXT.1, and the other half of the key split is [selection:
wrapped as specified in FCS_COP.1/KeyWrap
encrypted as specified in FCS_COP.1/KeyEnc or FCS_COP.1/KeyEncap
derived and not stored in non-volatile memory
]
the non-volatile memory the key is stored on is located in an external storage device for use as an authorization factor
the plaintext key is [selection:
used to wrap a key as specified in FCS_COP.1/KeyWrap
used to encrypt a key as specified in FCS_COP.1/KeyEnc or FCS_COP.1/KeyEncap
]
that is [selection:
already wrapped as specified in FCS_COP.1/KeyWrap,
already encrypted as specified in FCS_COP.1/KeyEnc or FCS_COP.1/KeyEncap,
Application
Note:
The plaintext key storage in non-volatile memory is allowed for several reasons. If the keys exist within protected memory that is not user accessible on the TOE
or OE, the only methods that allow it to play a security relevant role for protecting the BEV or the DEK are if it is a key split or providing additional layers
of wrapping or encryption on keys that have already been protected.
If the TSF implements key wrapping, key encryption, or key encapsulation to maintain protected cryptographic key storage, then FCS_COP.1/KeyWrap, FCS_COP.1/KeyEnc,
or FCS_COP.1/KeyEncap must be claimed. Additionally, if key wrapping or key encryption is used, then FCS_CKM.1/SKG, FCS_RBG.1, and FCS_COP.1/SKC must be claimed to
support generation, encryption, and decryption of symmetric keys used in support of these operations. If the TSF implements submask combining to maintain protected
cryptographic key storage, then FCS_SMC_EXT.1 must be claimed.
The evaluator shall verify the KMD to ensure it describes the storage location of all
keys and the protection of all keys stored in non-volatile memory. The description of
the key chain shall be reviewed to ensure the selected method is followed for the storage
of wrapped or encrypted keys in non-volatile memory and plaintext keys in non-volatile
memory meet one of the criteria for storage.
Tests
There are no test evaluation activities for this SFR.
The TSF shall define the following compliant power saving states: [selection, choose one of: S3, S4, G2(S5), G3, [assignment:
other power saving states]].
Application
Note:
Power saving states S3, S4, G2(S5), G3 are defined by the Advanced Configuration and Power Interface (ACPI) standard.
The evaluator shall validate the TSS contains a list of compliant power saving states.
Guidance
The evaluator shall ensure that guidance documentation contains a list of compliant
power saving states. If additional power saving states are supported, then the evaluator
shall validate that the guidance documentation states how non-compliant power states
are disabled.
There are no KMD evaluation activities for this SFR.
Tests
The evaluator shall confirm that for each listed compliant state all key/key materials
are removed from volatile memory by using the test defined in FCS_CKM.6.
For each compliant power saving state defined in FPT_PWR_EXT.1.1, the TSF shall enter
the compliant power saving state when the following conditions occur: user-initiated request, [selection: shutdown, user inactivity, request initiated by remote management system, [assignment:
other conditions], no other conditions].
Application
Note:
If volatile memory is not cleared as part of an unexpected power shutdown sequence then guidance documentation must define mitigation activities (e.g. how long users should wait after an unexpected power-down before volatile memory can be considered cleared).
The evaluator shall validate that the TSS contains a list of conditions under which the
TOE enters a compliant power saving state.
Guidance
The evaluator shall check that the guidance contains a list of conditions under which
the TOE enters a compliant power saving state. Additionally, the evaluator shall verify
that the guidance documentation states whether unexpected power-loss events may
result in entry to a non-compliant power saving state and, if that is the case, validate
that the documentation contains information on mitigation measures.
There are no KMD evaluation activities for this SFR.
Tests
The evaluator shall trigger each condition in the list of identified conditions and ensure
the TOE ends up in a compliant power saving state by running the test identified in
FCS_CKM.6.
The TSF shall verify updates to the TOE software using a [digital signature as specified in FCS_COP.1/SigVer] by the manufacturer prior to installing those updates.
Application
Note:
While this component requires the TOE to implement the update functionality itself, it is acceptable to perform the cryptographic checks using functionality available in the Operational Environment.
The evaluator shall examine the TSS to ensure that it describes information stating that
an authorized source signs TOE updates and will have an associated digital signature. The evaluator shall examine the TSS contains a definition of an authorized source along
with a description of how the TOE uses public keys for the update verification
mechanism in the Operational Environment. The evaluator ensures the TSS contains
details on the protection and maintenance of the TOE update credentials.
If the Operational Environment performs the signature verification, then the evaluator
shall examine the TSS to ensure it describes, for each platform identified in the ST, the
interfaces used by the TOE to invoke this cryptographic functionality.
Guidance
The evaluator ensures that the operational guidance describes how the TOE obtains
vendor updates to the TOE; the processing associated with verifying the digital
signature of the updates (as defined in FCS_COP.1/SigVer); and the actions that take place
for successful and unsuccessful cases.
There are no KMD evaluation activities for this SFR.
Tests
The evaluators shall perform the following tests (if the TOE supports multiple
signatures, each using a different hash algorithm, then the evaluator performs tests for
different combinations of authentic and unauthentic digital signatures and hashes, as
well as for digital signature alone):
Test FPT_TUD_EXT.1:1:
The evaluator performs the version verification activity to determine the current
version of the TOE. After the update tests described in the following tests, the evaluator
performs this activity again to verify that the version correctly corresponds to that of
the update.
Test FPT_TUD_EXT.1:2:
The evaluator performs the version verification activity to determine the current
version of the TOE. After the update tests described in the following tests, the evaluator
performs this activity again to verify that the version correctly corresponds to that of
the update.
5.1.4 TOE Security Functional Requirements Rationale
The following rationale provides justification for each SFR for the TOE,
showing that the SFRs are suitable to address the specified threats:
Mitigates this threat by requiring several options for enforcing validation, such as key sanitization of the DEK or when a configurable number of failed validation attempts is reached within a 24 hour period. This mitigates brute force attacks against authorization factors such as passwords and pins.
Mitigates this threat by ensuring the TSF provides the functions necessary to manage important aspects of the TOE including requests to change and erase the DEK.
Mitigates this threat by assigning users with the proper account permissions and privileges. This can be used with FMT_MOF.1 to restrict users to be able to modify certain power states covered in FMT_MOF.1.
Mitigates this threat by defining conditions in which the TOE will enter a compliant power state. These requirements ensure the device is secure if lost in a compliant power state.
Mitigates this threat by ensuring the TSF provides the functions necessary to manage important behavior of the TOE which includes the initiation of system firmware/software updates.
Mitigates this threat by providing authorized users the ability to query the current version of the TOE software/firmware, initiate updates, and verify updates prior to installation using a manufacturer digital signature.
5.2 Security Assurance Requirements
This cPP identifies the Security Assurance Requirements (SARs) to frame the extent to which
the evaluator assesses the documentation applicable for the evaluation and performs
independent testing. Individual evaluation activities to be performed are specified within
each SFR.
Note to ST authors: There is a selection in the ASE_TSS that must be completed. One cannot simply reference the SARs in this cPP.
The general model for evaluation of TOEs against STs written to conform to this cPP is as follows: after the ST has been approved for evaluation, the ITSEF will obtain the TOE, supporting environmental IT (if required), and the administrative/user guides for the TOE. The ITSEF is expected to perform actions mandated by the Common Evaluation Methodology (CEM) for the ASE and ALC SARs. The ITSEF also performs the Evaluation Activities contained within the SD, which are intended to be an interpretation of the other CEM assurance requirements as they apply to the specific technology instantiated in the TOE. The Evaluation Activities that are captured in the SD also provide clarification as to what the developer needs to provide to demonstrate the TOE is compliant with the cPP.
The ST is evaluated as per ASE activities defined in the CEM. In addition, there may be Evaluation Activities specified within the SD that call for necessary descriptions to be included in the TSS that are specific to the TOE technology type.
The SFRs in this cPP allow for conformant implementations to incorporate a wide range of acceptable key management approaches as long as basic principles are satisfied. Given the criticality of the key management scheme, this cPP requires the developer to provide a detailed description of their key management implementation. This information can be submitted as an appendix to the ST and marked proprietary, as this level of detailed information is not expected to be made publicly available. See Appendix E for details on the expectation of the developer’s Key Management Description
In addition, if the TOE includes a random bit generator Appendix D provides a description of the information expected to be provided regarding the quality of the entropy.
ASE_TSS.1.1C The TOE summary specification shall describe how the TOE meets each SFR, including a Key Management Description (Appendix E), and [selection: Entropy Essay, list of all of 3rd party software libraries (including version numbers), 3rd party hardware components (including model/version numbers), no other cPP specified proprietary documentation].
5.2.2 ADV: Development
The design information about the TOE is contained in the guidance documentation available to the end user as well as the TSS portion of the ST, and any additional information required by this cPP that is not to be made public (e.g., Entropy Essay).
The functional specification describes the TOE Security Functions Interfaces (TSFIs). It is not necessary to have a formal or complete specification of these interfaces. Additionally, because TOEs conforming to this cPP may have interfaces to the Operational Environment that are not directly invoked by TOE users, there is little point
specifying that such interfaces be described in and of themselves since only indirect testing of such interfaces may be possible. For this cPP, the evaluation activities
for this family focus on understanding the interfaces presented in the TSS in response to the functional requirements and the interfaces presented in the AGD documentation. No additional “functional specification” documentation is necessary to satisfy the evaluation activities specified.
The evaluation activities are associated with the applicable SFRs. Since these are directly associated with the SFRs, the tracing in element ADV_FSP.1.2D is implicitly
already done and no additional documentation is necessary.
The developer shall provide a tracing from the functional specification to the
SFRs.
Application
Note:
As indicated in the introduction to this section, the
functional specification is comprised of the information contained in the AGD_OPE and
AGD_PRE documentation. The developer may reference a website accessible to application
developers and the evaluator. The evaluation activities in the functional requirements
point to evidence that should exist in the documentation and TSS
section; since these are directly associated with the SFRs, the tracing in element
ADV_FSP.1.2D is implicitly already done and no additional documentation is
necessary.
There are no specific evaluation activities associated with these SARs, except
ensuring the information is provided. The functional specification documentation is
provided to support the evaluation activities described in Section 5.1 Security Functional Requirements, and
other activities described for AGD, ATE, and AVA SARs. The requirements on the content
of the functional specification information is implicitly assessed by virtue of the
other evaluation activities being performed; if the evaluator is unable to perform an
activity because there is insufficient interface information, then an adequate
functional specification has not been provided.
5.2.3 AGD: Guidance Documentation
The guidance documents will be provided with the ST. Guidance must include a description of how the IT personnel verifies that
the Operational Environment can fulfill its role for the security functionality. The documentation should be in an informal style
and readable by the IT personnel.
Guidance must be provided for every operational environment that the product supports as claimed in the ST. This guidance
includes:
Instructions to successfully install the TSF in that environment; and
Instructions to manage the security of the TSF as a product and as a component of the larger operational environment
Instructions to provide a protected administrative capability.
Guidance pertaining to particular security functionality must also be provided; requirements on such guidance are contained in
the evaluation activities
AGD_OPE.1 Operational User Guidance (AGD_OPE.1)
The operational user guidance does not have to be contained in a single document. Guidance to users, administrators, and
integrators can be spread among documents or web pages.
The developer should review the evaluation activities to ascertain the specifics of the guidance that the evaluator will be
checking for. This will provide the necessary information for the preparation of acceptable guidance.
The developer shall provide operational user guidance.
Application
Note:
The operational user guidance does not have to be contained in a
single document. Guidance to users, administrators and application developers can be
spread among documents or web pages. Where appropriate, the guidance documentation is
expressed in the eXtensible Configuration Checklist Description Format (XCCDF) to
support security automation. Rather than repeat information here, the developer should
review the evaluation activities for this component to ascertain the specifics of the
guidance that the evaluator will be checking for. This will provide the necessary
information for the preparation of acceptable guidance.
The operational user guidance shall describe, for each user role, the
user-accessible functions and privileges that should be controlled in a secure
processing environment, including appropriate warnings.
Application
Note:
User and administrator are to be considered in the definition
of user role.
The operational user guidance shall describe, for each user role, the available
functions and interfaces, in particular all security parameters under the control of
the user, indicating secure values as appropriate.
The operational user guidance shall, for each user role, clearly present each
type of security-relevant event relative to the user-accessible functions that need to
be performed, including changing the security characteristics of entities under the
control of the TSF.
The operational user guidance shall identify all possible modes of operation of
the TOE (including operation following failure or operational
error), their consequences, and implications for maintaining secure operation.
The operational user guidance shall, for each user role, describe the security
measures to be followed in order to fulfill the security objectives for the
operational environment as described in the ST.
Some of the contents of the operational guidance will be verified by the
evaluation activities in Section 5.1 Security Functional Requirements and evaluation of the TOE
according to the [CEM]. The following additional
information is also required.
If cryptographic functions are provided by the
TOE, the operational guidance shall contain instructions for
configuring the cryptographic engine associated with the evaluated configuration of
the TOE. It shall provide a warning to the administrator that use of
other cryptographic engines was not evaluated nor tested during the CC evaluation of
the TOE.
The documentation must describe the process for verifying
updates to the TOE by verifying a digital signature – this may
be done by the TOE or the underlying platform.
The evaluator shall verify that this process includes the following steps:
Instructions for obtaining the
update itself. This should include instructions for making the update accessible to
the TOE (e.g., placement in a specific directory).
Instructions for initiating the update process, as well as discerning whether the process was
successful or unsuccessful. This includes generation of the digital signature.
The TOE will likely contain security functionality that does not
fall in the scope of evaluation under this PP. The operational guidance shall make it
clear to an administrator which security functionality is covered by the evaluation
activities.
AGD_PRE.1 Preparative Procedures (AGD_PRE.1)
As with the operational guidance, the developer should look to the Evaluation Activities to determine the required content with respect to preparative procedures.
The developer shall provide the TOE, including its preparative procedures.
Application
Note:
As with the operational guidance, the developer should look to
the evaluation activities to determine the required content with respect to preparative
procedures.
The preparative procedures shall describe all the steps necessary for secure
acceptance of the delivered TOE in accordance with the developer's
delivery procedures.
The preparative procedures shall describe all the steps necessary for secure
installation of the TOE and for the secure preparation of the
operational environment in accordance with the security objectives for the operational
environment as described in the ST.
As indicated in the introduction above, there are significant expectations
with respect to the documentation—especially when configuring the operational
environment to support TOE functional requirements. The evaluator
shall check to ensure that the guidance provided for the TOE
adequately addresses all platforms claimed for the TOE in the ST.
5.2.4 Class ALC: Life-cycle Support
At the assurance level provided for TOEs conformant to this cPP, life-cycle support is limited to end-user-visible aspects of the life-cycle, rather than an examination of the TOE vendor’s development and configuration management process. This is not meant to diminish the critical role that a developer’s practices play in contributing to the overall trustworthiness of a product; rather, it is a reflection on the information to be made available for evaluation at this assurance level.
ALC_CMC.1 Labelling of the TOE (ALC_CMC.1)
This component is targeted at identifying the TOE such that it can be distinguished from other products or versions from the same vendor and can be easily specified when being procured by an end user. The evaluator performs the CEM work units associated with ALC_CMC.1.
The evaluator shall check the ST to ensure that it contains an identifier
(such as a product name/version number) that specifically identifies the version that
meets the requirements of the ST. Further, the evaluator shall check the operational guidance
and TOE samples received for testing to ensure that the version
number is consistent with that in the ST. If the vendor maintains a website
advertising the TOE, the evaluator shall examine the information on
the website to ensure that the information in the ST is sufficient to distinguish the
product.
ALC_CMS.1 TOE CMS Coverage (ALC_CMS.1)
Given the scope of the TOE and its associated evaluation evidence requirements, the evaluator performs the CEM work units associated with ALC_CMS.1.
The "evaluation evidence required by the SARs" in this PP is limited to the
information in the ST coupled with the guidance provided to administrators and users
under the AGD requirements. By ensuring that the TOE is specifically
identified and that this identification is consistent in the ST and in the AGD
guidance (as done in the evaluation activity for ALC_CMC.1), the evaluator implicitly
confirms the information required by this component. Life-cycle support is targeted
aspects of the developer’s life-cycle and instructions to providers of applications
for the developer’s devices, rather than an in-depth examination of the TSF
manufacturer’s development and configuration management process. This is not meant to diminish the critical role that a developer’s practices play in
contributing to the overall trustworthiness of a product; rather, it’s a reflection on
the information to be made available for evaluation.
The evaluator shall ensure that the developer has identified (in guidance documentation for application
developers concerning the targeted platform) one or more development environments
appropriate for use in developing applications for the developer’s platform. For each
of these development environments, the developer shall provide information on how to
configure the environment to ensure that buffer overflow protection mechanisms in the
environment(s) are invoked (e.g., compiler flags). The evaluator shall ensure that
this documentation also includes an indication of whether such protections are on by
default, or have to be specifically enabled. The evaluator shall ensure that the
TSF is uniquely identified (with respect to other products from the
TSF vendor), and that documentation provided by the developer in
association with the requirements in the ST is associated with the
TSF using this unique identification.
5.2.5 Class ATE: Tests
Testing is specified for functional aspects of the system as well as aspects that take advantage of design or implementation weaknesses. The former is done through the ATE_IND family, while the latter is through the AVA_VAN family. For this cPP, testing is based on advertised functionality and interfaces with dependency on the availability of design information. One of the primary outputs of the evaluation process is the test report as specified in the following requirements.
Testing is performed to confirm the functionality described in the TSS as well as the operational guidance (includes “evaluated configuration” instructions). The focus of the testing is to confirm that the requirements specified in Section 5 are being met. The Evaluation Activities in the SD identify the specific testing activities necessary to verify compliance with the SFRs. The evaluator produces a test report documenting the plan for and results of testing, as well as coverage arguments focused on the platform/TOE combinations that are claiming conformance to this cPP.
Application
Note:
The developer must provide at least one product instance of the TOE for complete testing on at least one
platform regardless of equivalency. See the Equivalency Appendix for more details.
The evaluator shall prepare a test plan and report documenting the testing
aspects of the system, including any application crashes during testing. The evaluator
shall determine the root cause of any application crashes and include that information
in the report. The test plan covers all of the testing actions contained in
the [CEM] and the body of this PP’s evaluation activities.
While it is not necessary to have one test case per test listed in an evaluation activity, the
evaluator must document in the test plan that each applicable testing requirement in
the ST is covered. The test plan identifies the platforms to be tested, and for those
platforms not included in the test plan but included in the ST, the test plan provides
a justification for not testing the platforms. This justification must address the
differences between the tested platforms and the untested platforms, and make an
argument that the differences do not affect the testing to be performed. It is not
sufficient to merely assert that the differences have no effect; rationale must be
provided. If all platforms claimed in the ST are tested, then no rationale is
necessary. The test plan describes the composition of each platform to be tested, and
any setup that is necessary beyond what is contained in the AGD documentation. It
should be noted that the evaluator is expected to follow the AGD documentation for
installation and setup of each platform either as part of a test or as a standard
pre-test condition. This may include special test drivers or tools. For each driver or
tool, an argument (not just an assertion) should be provided that the driver or tool
will not adversely affect the performance of the functionality by the TOE and its platform.
This also includes the configuration of the
cryptographic engine to be used. The cryptographic algorithms implemented by this
engine are those specified by this PP and used by the cryptographic protocols being
evaluated (e.g., SSH). The test plan identifies high-level test objectives
as well as the test procedures to be followed to achieve those objectives. These
procedures include expected results.
The test report (which could just be an annotated
version of the test plan) details the activities that took place when the test
procedures were executed, and includes the actual results of the tests. This shall be
a cumulative account, so if there was a test run that resulted in a failure; a fix
installed; and then a successful re-run of the test, the report would show a “fail”
and “pass” result (and the supporting details), and not just the “pass” result.
5.2.6 Class AVA: Vulnerability Assessment
For the current generation of this cPP, the iTC is expected to survey open sources to discover what vulnerabilities have been
discovered in these types of products and provide that content into the AVA_VAN discussion. In most cases, these vulnerabilities
will require sophistication beyond that of a basic attacker. This information will be used in the development of future Protection
Profiles.
If the TOE is a Network Attached Storage (NAS) device, the evaluator shall verify as part of the vulnerability assessment that
remote management services are either not present or can be fully disabled.
AVA_VAN.1 Vulnerability Survey (AVA_VAN.1)
Vulnerability Analysis
Sources of Vulnerability Information
CEM Work Unit AVA_VAN.1-3 is supplemented here to provide a better-defined set of flaws to
investigate and procedures to follow based on this particular technology. Terminology used is based on the flaw hypothesis
methodology, where the evaluation team hypothesizes flaws and then either proves or disproves those flaws (a flaw is equivalent
to a “potential vulnerability” as used in the CEM). Flaws are categorized into four “types” depending on how they are
formulated:
A list of flaw hypotheses applicable to the technology described by the cPP derived from public sources as documented in
the Type 1 Hypotheses section—this fixed set has been agreed to by the iTC. Additionally, this will be supplemented with entries for a set
of public sources (as indicated below) that are directly applicable to the TOE or its identified components (as defined by
the process in the Type 1 Hypotheses section below); this is to ensure that the evaluators include in their assessment applicable entries
that have been discovered since the cPP was published;
A list of flaw hypotheses contained in this document that are derived from lessons learned specific to that technology and
other iTC input (that might be derived from other open sources and vulnerability databases, for example) as documented in
the Type 2 Hypotheses section;
A list of flaw hypotheses derived from information available to the evaluators; this includes the baseline evidence
provided by the vendor described in this document (documentation associated with EAs, documentation described in
the Vulnerability Survey section), as well as other information (public and/or based on evaluator experience) as documented in the Type 3 Hypotheses
section; and
A list of flaw hypotheses that are generated through the use of iTC-defined tools (e.g., nmap, protocol testers) and their
application is specified in the Type 4 Hypotheses section.
Type 1 Hypotheses-Public-Vulnerability-Based
The following list of public sources of vulnerability information was selected by the iTC:
Search Common Vulnerabilities and Exposures: http://cve.mitre.org/cve/
Search the National Vulnerability Database: https://nvd.nist.gov/
In order to successfully complete this activity, the evaluator will use the developer provided list of all of third party library
information that is used as part of their product, along with the version and any other identifying information (this is required
in the cPP as part of the ASE_TSS.1.1C requirement). This applies to hardware (including chipsets, etc.) that a vendor utilizes
as part of their TOE. This TOE-unique information will be used in the search terms the evaluator uses in addition to those listed
above.
The evaluator will also consider the requirements that are chosen and the appropriate guidance that is tied to each requirement.
In order to supplement this list, the evaluators shall also perform a search on the sources listed above to determine a list of
potential flaw hypotheses that are more recent that the publication date of the cPP, and those that are specific to the TOE and
its components as specified by the additional documentation mentioned above. Any duplicates – either in a specific entry, or in
the flaw hypothesis that is generated from an entry from the same or a different source – can be noted and removed from
consideration by the evaluation team.
As part of type 1 flaw hypothesis generation for the specific components of the TOE, the evaluator shall also search the
component manufacturer’s websites to determine if flaw hypotheses can be generated on this basis (for instance, if security
patches have been released for the version of the component being evaluated, the subject of those patches may form the basis
for a flaw hypothesis).
The iTC has leveraged the expertise of the developers and the evaluation labs to diligently develop the appropriate search
terms and vulnerability databases. They have also thoughtfully considered the iTC-sourced hypotheses the evaluators should
use based upon the applicable use case and the threats to be mitigated by the SFRs. Therefore, it is the intent of the iTC,
for the evaluation to focus all effort on the Type 1 and Type 2 Hypotheses and has decided that Type 3 Hypotheses are not
necessary.
However, if the evaluators discover a Type 3 potential flaw that they believe should be considered, they should work with
their Certification Body to determine the feasibility of pursuing the hypothesis. The Certification Body may determine
whether the potential flaw hypotheses is worth submitting to the iTC for consideration as Type 2 hypotheses in future drafts
of the cPP/SD.
Type 4 Hypotheses-Evaluation-Team-Generated
The iTC has called out several tools that should be used during the Type 2 hypotheses process. Therefore, the use of any tools
is covered within the Type 2 construct and the iTC does not see any additional tools that are necessary. The use case for
Version 2 of this cPP is rather straightforward – the device is found in a powered down state and has not been subjected to
revisit/evil maid attacks. Since that is the use case, the iTC has also assumed there is a trusted channel between the AA and
EE. Since the use case is so narrow, and is not a typical model for penetration or fuzzing testing, the normal types of
testing do not apply. Therefore, the relevant types of tools are referenced in Type 2.
Process for Evaluator Vulnerability Analysis
As flaw hypotheses are generated from the activities described above, the evaluation team will disposition them; that is,
attempt to prove, disprove, or determine the non-applicability of the hypotheses. This process is as follows. The evaluator will refine each flaw hypothesis for the TOE and attempt to disprove it using the information provided by the
developer or through penetration testing. During this process, the evaluator is free to interact directly with the developer
to determine if the flaw exists, including requests to the developer for additional evidence (e.g., detailed design
information, consultation with engineering staff); however, the CB should be included in these discussions. Should the
developer object to the information being requested as being not compatible with the overall level of the evaluation
activity/cPP and cannot provide evidence otherwise that the flaw is disproved, the evaluator prepares an appropriate set of
materials as follows:
The source documents used in formulating the hypothesis, and why it represents a potential compromise against a
specific TOE function;
An argument why the flaw hypothesis could not be proven or disproved by the evidence provided so far; and
The type of information required to investigate the flaw hypothesis further.
The Certification Body (CB) will then either approve or disapprove the request for additional information. If approved, the
developer provides the requested evidence to disprove the flaw hypothesis (or, of course, acknowledge the flaw).
For each hypothesis, the evaluator will note whether the flaw hypothesis has been successfully disproved, successfully proven
to have identified a flaw, or requires further investigation. It is important to have the results documented as outlined in
the Reporting section below. If the evaluator finds a flaw, the evaluator must report these flaws to the developer. All reported flaws must be addressed
as follows:
If the developer confirms that the flaw exists and that it is exploitable at Basic Attack Potential, then a change is made by
the developer, and the resulting resolution is agreed by the evaluator and noted as part of the evaluation report.
If the developer, the evaluator, and the CB agree that the flaw is exploitable only above Basic Attack Potential and does not
require resolution for any other reason, then no change is made and the flaw is noted as a residual vulnerability in the
CB-internal report (ETR).
If the developer and evaluator agree that the flaw is exploitable only above Basic Attack Potential, but it is deemed critical
to fix because of technology-specific or cPP-specific aspects such as typical use cases or operational environments, then a
change is made by the developer, and the resulting resolution is agreed by the evaluator and noted as part of the evaluation
report.
Disagreements between evaluator and vendor regarding questions of the existence of a flaw, its attack potential, or whether
it should be deemed critical to fix are resolved by the CB.
Any testing performed by the evaluator shall be documented in the test report as outlined
in the Reporting section below.
As indicated in the Reporting section, the public statement with respect to vulnerability analysis that is performed on TOEs
conformant to the cPP is constrained to coverage of flaws associated with Types 1 and 2 (defined in the Sources of
Vulnerability Information section) flaw hypotheses only. The fact that the iTC generates these candidate hypotheses indicates
these must be addressed.
Reporting
The evaluators shall produce two reports on the testing effort; one that is public-facing (that is, included in the
non-proprietary evaluation report, which is a subset of the Evaluation Technical Report (ETR)), and the complete ETR that is
delivered to the overseeing CB.
The public-facing report contains:
The flaw identifiers returned when the procedures for searching public sources were followed according to instructions in
the Type 1 Hypotheses section;
A statement that the evaluators have examined the Type 1 flaw hypotheses specified
in this document in the
Type 1 Hypotheses section (i.e. the flaws listed in the previous bullet) and the Type 2 flaw hypotheses specified in the
the Type 2 Hypotheses section
No other information is provided in the public-facing report.
The internal CB report contains, in addition to the information in the public-facing report:
a list of all of the flaw hypotheses generated (cf. AVA_VAN.1-4);
the evaluator penetration testing effort, outlining the testing approach, configuration, depth and results (cf. AVA_VAN.1-9);
all documentation used to generate the flaw hypotheses (in identifying the documentation used in coming up with the
flaw hypotheses, the evaluation team must characterize the documentation so that a reader can determine whether it is
strictly required in this document, and the nature of the documentation (design information, developer
engineering notebooks, etc.));
the evaluator shall report all exploitable vulnerabilities and residual vulnerabilities, detailing for each:
its source (e.g. CEM activity being undertaken when it was conceived, known to the evaluator, read in a publication)
whether it is exploitable in its operational environment or not (i.e. exploitable or residual).
the amount of time, level of expertise, level of knowledge of the TOE, level of opportunity and the equipment
required to perform the identified vulnerabilities (cf. AVA_VAN.1-11);
how each flaw hypothesis was resolved (this includes whether the original flaw hypothesis was confirmed or
disproved, and any analysis relating to whether a residual vulnerability is exploitable by an attacker with Basic
Attack Potential) (cf. AVA_VAN1-10); and
in the case that actual testing was performed in the investigation (either as part of flaw hypothesis generation
using tools specified by the iTC in the Type 4 Hypotheses section, or in proving or disproving a particular flaw) the steps followed in
setting up the TOE (and any required test equipment); executing the test; post-test procedures; and the actual results
(to a level of detail that allow repetition of the test, including the following:
identification of the potential vulnerability the TOE is being tested for;
instructions to connect and setup all required test equipment as required to conduct the penetration test;
instructions to establish all penetration test prerequisite initial conditions;
Application
Note:
Suitability for testing means not being obfuscated or
packaged in such a way as to disrupt either static or dynamic analysis by the
evaluator.
The evaluator shall perform a search of public domain sources to identify
potential vulnerabilities in the TOE.
Application
Note:
Public domain sources include the Common Vulnerabilities
and Exposures (CVE) dictionary for publicly known vulnerabilities. Public domain
sources also include sites which provide free checking of files for viruses.
The evaluator shall conduct penetration testing, based on the identified
potential vulnerabilities, to determine that the TOE is resistant to
attacks performed by an attacker possessing Basic attack potential.
The evaluator shall generate a report to document their findings with respect to this
requirement. This report could physically be part of the overall test report mentioned in
ATE_IND, or a separate document. The evaluator performs a search of public information to find
vulnerabilities that have been found in similar applications with a particular focus on network
protocols the application uses and document formats it parses.
The evaluator documents the sources consulted and the vulnerabilities found in the report.
For each vulnerability found, the evaluator either provides a rationale with respect to its
non-applicability, or the evaluator formulates a test (using the guidelines provided in ATE_IND)
to confirm the vulnerability, if suitable. Suitability is determined by assessing the attack
vector needed to take advantage of the vulnerability. If exploiting the vulnerability requires
expert skills and an electron microscope, for instance, then a test would not be suitable and
an appropriate justification would be formulated.
The evaluator shall also run a virus scanner with the most current virus definitions against the
application files and verify that no files are flagged as malicious.
Appendix A - Optional Requirements
As indicated in the introduction to this PP, the baseline requirements (those that must be
performed by the TOE) are contained in the body of this PP. This appendix contains three other types of optional requirements:
The first type, defined in Appendix A.1 Strictly Optional Requirements, are strictly optional requirements. If the TOE meets any of these requirements the vendor is encouraged to claim the associated SFRs
in the ST, but doing so is not required in order to conform to this PP.
The second type, defined in Appendix A.2 Objective Requirements, are objective requirements. These describe security functionality that is not yet
widely available in commercial technology.
Objective requirements are not currently mandated by this PP, but will be mandated in
the future. Adoption by vendors is encouraged, but claiming these SFRs is not required in order to conform to this
PP.
The third type, defined in Appendix A.3 Implementation-dependent Requirements, are Implementation-dependent requirements. If the TOE implements the product features associated with the listed SFRs, either the SFRs must be claimed
or the product features must be disabled in the evaluated configuration.
A.1 Strictly Optional Requirements
A.1.1 Class ALC: Life-cycle Support
ALC_FLR.1 Basic Flaw Remediation (ALC_FLR.1)
This SAR is optional and may be claimed at the ST-Author's discretion.
The flaw remediation procedures shall require that a description of the nature and effect
of each security flaw be provided, as well as the status of finding a correction to that flaw.
The flaw remediation procedures documentation shall describe the methods used to
provide flaw information, corrections and guidance on corrective actions to TOE users.
The flaw remediation procedures shall require that a description of the nature and effect of each
security flaw be provided, as well as the status of finding a correction to that flaw.
The flaw remediation procedures documentation shall describe the methods used to provide flaw
information, corrections and guidance on corrective actions to TOE users.
The flaw remediation procedures shall describe a means by which the developer receives
from TOE users reports and enquiries of suspected security flaws in the TOE.
The procedures for processing reported security flaws shall ensure that any reported
flaws are remediated and the remediation procedures issued to TOE users.
The procedures for processing reported security flaws shall provide safeguards that any
corrections to these security flaws do not introduce any new flaws.
The flaw remediation procedures shall require that a description of the nature and effect of each
security flaw be provided, as well as the status of finding a correction to that flaw.
The flaw remediation procedures documentation shall describe the methods used to provide flaw
information, corrections and guidance on corrective actions to TOE users.
The flaw remediation procedures shall describe a means by which the developer receives from
TOE users reports and enquiries of suspected security flaws in the TOE.
The flaw remediation procedures shall include a procedure requiring timely response and
the automatic distribution of security flaw reports and the associated corrections to
registered users who might be affected by the security flaw.
The procedures for processing reported security flaws shall ensure that any reported flaws are
remediated and the remediation procedures issued to TOE users.
The procedures for processing reported security flaws shall provide safeguards that any
corrections to these security flaws do not introduce any new flaws.
The flaw remediation guidance shall describe a means by which TOE users may register
with the developer, to be eligible to receive security flaw reports and corrections.
Reminder - Update all crypto SFRs with the crypto catalog versions when available.
The TSF shall generate asymmetric cryptographic keys in accordance with a specified cryptographic key generation algorithm: [selection:
RSA schemes using cryptographic key sizes of [selection: 2048-bit, 3072-bit, 4096-bit] that meet the following: FIPS PUB 186-4, “Digital Signature Standard (DSS)”, Appendix B.3
ECC schemes using “NIST curves” of [selection: P-256, P-384, P-521] that meet the following: FIPS PUB 186-4, “Digital Signature Standard (DSS)”, Appendix B.4
FFC schemes using cryptographic key sizes of
[selection: 2048-bit, 3072-bit, 4096-bit] that meet the following: FIPS PUB 186-4, “Digital Signature Standard (DSS)”, Appendix B.1
]and specified cryptographic key sizes
[assignment:
cryptographic key sizes]
that meet the following:
[assignment:
list of standards].
Application
Note:
Asymmetric keys may be used to “wrap” a key or submask. This SFR should be included by the ST author when making the appropriate selection in FCS_COP.
The evaluator shall ensure that the TSS identifies the key sizes supported by the TOE. If the ST specifies more than one scheme, the evaluator shall examine the TSS to verify
that it identifies the usage for each scheme.
Guidance
The evaluator shall verify that the AGD guidance instructs the administrator how to
configure the TOE to use the selected key generation schemes and key sizes for all
uses specified by the AGD documentation and defined in this cPP.
If the TOE uses an asymmetric key as part of the key chain, the KMD should detail
how the asymmetric key is used as part of the key chain.
Tests
The following tests require the developer to provide access to a test platform that
provides the evaluator with tools that are typically not found on factory products.
The evaluator shall verify the implementation of RSA Key Generation by the TOE
using the Key Generation test. This test verifies the ability of the TSF to correctly
produce values for the key components including the public verification exponent e,
the private prime factors p and q, the public modulus n and the calculation of the private
signature exponent d.
Key Pair generation specifies 5 ways (or methods) to generate the primes p and q. These
include:
Random Primes:
Provable primes
Probable primes
Primes with Conditions:
Primes p1, p2, q1,q2, p and q shall all be provable primes
Primes p1, p2, q1, and q2 shall be provable primes and p and q shall be probable primes
Primes p1, p2, q1,q2, p and q shall all be probable primes
To test the key generation method for the Random Provable primes method and for all
the Primes with Conditions methods, the evaluator must seed the TSF key generation
routine with sufficient data to deterministically generate the RSA key pair. This
includes the random seeds, the public exponent of the RSA key, and the desired key
length. For each key length supported, the evaluator shall have the TSF generate 25
key pairs. The evaluator shall verify the correctness of the TSF’s implementation by
comparing values generated by the TSF with those generated from a known good
implementation.
For each supported NIST curve, i.e., P-256, P-384 and P-521, the evaluator shall
require the implementation under test (IUT) to generate 10 private/public key pairs. The private key shall be generated using an approved random bit generator (RBG). To
determine correctness, the evaluator shall submit the generated key pairs to the public
key verification (PKV) function of a known good implementation.
For each supported NIST curve, i.e., P-256, P-384 and P-521, the evaluator shall
generate 10 private/public key pairs using the key generation function of a known good
implementation and modify five of the public key values so that they are incorrect,
leaving five values unchanged (i.e., correct). The evaluator shall obtain in response a
set of 10 PASS/FAIL values.
Key Generation for Finite-Field Cryptography (FFC)
The evaluator shall verify the implementation of the Parameters Generation and the
Key Generation for FFC by the TOE using the Parameter Generation and Key
Generation test. This test verifies the ability of the TSF to correctly produce values for
the field prime p, the cryptographic prime q (dividing p-1), the cryptographic group
generator g, and the calculation of the private key x and public key y.
The Parameter generation specifies 2 ways (or methods) to generate the cryptographic
prime q and the field prime p:
Cryptographic and Field Primes:
Primes q and p shall both be provable primes
Primes q and field prime p shall both be probable primes
and two ways to generate the cryptographic group generator g:
Cryptographic Group Generator:
Generator g constructed through a verifiable process
Generator g constructed through an unverifiable process.
The Key generation specifies 2 ways to generate the private key x:
len(q) + 64 bit output of RBG, followed by a mod q-1 operation and +1
operation where 1<= x<=q-1.
The security strength of the RBG must be at least that of the security offered by the
FFC parameter set.
To test the cryptographic and field prime generation method for the provable primes
method and/or the group generator g for a verifiable process, the evaluator must seed
the TSF parameter generation routine with sufficient data to deterministically generate
the parameter set.
For each key length supported, the evaluator shall have the TSF generate 25 parameter
sets and key pairs. The evaluator shall verify the correctness of the TSF’s
implementation by comparing values generated by the TSF with those generated from
a known good implementation. Verification must also confirm.
This PP does not define any
Objective requirements.
A.3 Implementation-dependent Requirements
This PP does not define any
Implementation-dependent requirements.
Appendix B - Selection-based Requirements
As indicated in the introduction to this PP,
the baseline requirements
(those that must be performed by the TOE or its underlying platform)
are contained in the body of this PP. There are additional requirements based on selections in the body of
the PP:
if certain selections are made, then additional requirements below must be included.
The TSF shall generate symmetric cryptographic keys using a Random Bit Generator as specified in FCS_RBG.1 and specified cryptographic key
sizes [selection: 128 bit, 256 bit] that meet the following: [no standard].
Application
Note:
Symmetric keys may be used to generate keys along the key chain. Any instance in where the TSFDRBG is referenced for key generation (as in FCS_AFA_EXT.1,
FCS_SNI_EXT.1, and FCS_KDF_EXT.1), or where the TSF generates or re-generates key encryption or key wrapping keys as part of deriving a key or validating
an authorization factor (as in FCS_KYC_EXT.1, FPT_KYP_EXT.1, and FCS_VAL_EXT.1)
The evaluator shall review the TSS to determine that a symmetric key is supported by
the product, that the TSS includes a description of the protection provided by the
product for this key. The evaluator shall ensure that the TSS identifies the key sizes
supported by the TOE.
Guidance
The evaluator shall verify that the AGD guidance instructs the administrator how to
configure the TOE to use the selected key sizes for all uses specified by the AGD
documentation and defined in this cPP.
The TSF shall perform [cryptographic keyed-hash message authentication] in accordance with a specified cryptographic algorithm [selection: HMAC-SHA-256, HMAC-SHA-384, HMAC-SHA-512] and cryptographic key sizes [assignment:
key size (in bits) used in HMAC] that meet the following: [ISO/IEC 9797-2:2011, Section 7 “MAC Algorithm 2”].
Application
Note:
The key size [k] in the assignment falls into a range between L1 and L2 (defined in ISO/IEC 10118 for the appropriate hash function for
example for SHA-256 L1 = 512, L2 =256) where L2 ≤ k ≤ L1.
This SFR is required when the TSF performs a key derivation operation as part of maintaining and deriving a key chain (FCS_KDF_EXT.1,
FCS_KYC_EXT.1) or when the TSF performs validation of a submask, intermediate key, or BEV using a keyed hash operation (FCS_VAL_EXT.1).
The evaluator shall examine the TSS to ensure that it specifies the following values
used by the HMAC function: key length, hash function used, block size, and output
MAC length used.
If CMAC was selected:
The evaluator shall examine the TSS to ensure that it specifies the following
values used by the CMAC function: key length, block cipher used, block size
(of the cipher), and output MAC length used.
Guidance
There are no AGD evaluation activities for this SFR.
For each of the supported parameter sets, the evaluator shall compose 15 sets of test
data. Each set shall consist of a key and message data. The evaluator shall have the TSF
generate HMAC tags for these sets of test data. The resulting MAC tags shall be
compared to the result of generating HMAC tags with the same key using a known
good implementation.
If CMAC was selected:
For each of the supported parameter sets, the evaluator shall compose at least
15 sets of test data. Each set shall consist of a key and message data. The test
data shall include messages of different lengths, some with partial blocks as the
last block and some with full blocks as the last block. The test data keys shall
include cases for which subkey K1 is generated both with and without using the
irreducible polynomial R_b, as well as cases for which subkey K2 is generated
from K1 both with and without using the irreducible polynomial R_b. (The
subkey generation and polynomial R_b are as defined in SP800-38E.) The
evaluator shall have the TSF generate CMAC tags for these sets of test data. The resulting MAC tags shall be compared to the result of generating CMAC
tags with the same key using a known good implementation.
The TSF shall perform [key encryption and decryption] in accordance with a specified cryptographic algorithm [AES used in [selection: CBC, GCM] mode] and cryptographic key sizes [selection: 128 bits, 256 bits] that meet the following: [AES as specified in ISO /IEC 18033-3, [selection: CBC as specified in ISO/IEC 10116, GCM as specified in ISO/IEC 19772]].
Application
Note:
This requirement is used in the body of the ST if the ST author chooses to use AES encryption/decryption for protecting the keys as part of the key chaining
approach that is specified in FCS_KYC_EXT.1.
This SFR is required when the TSF performs key encryption as part of maintaining and deriving a key chain (FCS_KDF_EXT.1, FCS_KYC_EXT.1) or when the TSF
uses key encryption as part of password conditioning.
The evaluator shall verify the TSS includes a description of the key size used for
encryption and the mode used for the key encryption.
Guidance
If multiple key encryption modes are supported, the evaluator examines the guidance
documentation to determine that the method of choosing a specific mode/key size by
the end user is described.
The TSF shall perform [key transport] in accordance with a specified
cryptographic algorithm [RSA in the following modes [selection: KTS-OAEP, KTS-KEM-KWS] and the cryptographic key size [selection: 2048 bits, 3072 bits] that meet the following: [NIST SP 800-56B, Revision 1].
Application
Note:
This requirement is used in the body of the ST if the ST author chooses to use key transport in the key chaining approach that is specified in
FCS_KYC_EXT.1.
This SFR is required when the TSF performs key encryption as part of maintaining and deriving a key chain (FCS_KDF_EXT.1, FCS_KYC_EXT.1) or
when the TSF uses key encryption as part of password conditioning.
The evaluator shall verify the TSS provides a high level description of the RSA scheme
and the cryptographic key size that is being used, and that the asymmetric algorithm
being used for key transport is RSA. If more than one scheme/key size are allowed,
then the evaluator shall make sure and test all combinations of scheme and key size. There may be more than one key size to specify – an RSA modulus size (and/or
encryption exponent size), an AES key size, hash sizes, MAC key/MAC tag size.
If the KTS-OAEP scheme was selected, the evaluator shall verify that the TSS
identifies the hash function, the mask generating function, the random bit generator,
the encryption primitive and decryption primitive.
If the KTS-KEM-KWS scheme was selected, the evaluator shall verify that the TSS
identifies the key derivation method, the AES-based key wrapping method, the secret
value encapsulation technique, and the random number generator.
Guidance
There are no AGD evaluation activities for this SFR.
There are no KMD evaluation activities for this SFR.
Tests
For each supported key transport schema, the evaluator shall initiate at least 25 sessions
that require key transport with an independently developed remote instance of a key
transport entity, using known RSA key-pairs. The evaluator shall observe traffic passed
from the sender-side and to the receiver-side of the TOE, and shall perform the
following tests, specific to which key transport scheme was employed.
If the KTS-OAEP scheme was selected, the evaluator shall perform the following tests:
Test FCS_COP.1/KeyEncap:1:
The evaluator shall inspect each cipher text, C, produced by the RSA-OAEP
encryption operation of the TOE and make sure it is the correct length, either 256
or 384 bytes depending on RSA key size. The evaluator shall also feed into the
TOE’s RSA-OEAP decryption operation some cipher texts that are the wrong
length and verify that the erroneous input is detected and that the decryption
operation exits with an error code.
Test FCS_COP.1/KeyEncap:2:
The evaluator shall convert each cipher text, C, produced by the RSA-OAEP
encryption operation of the TOE to the correct cipher text integer, c, and use the
decryption primitive to compute em = RSADP((n,d),c) and convert em to the
encoded message EM. The evaluator shall then check that the first byte of EM is
0x00. The evaluator shall also feed into the TOE’s RSA-OEAP decryption
operation some cipher texts where the first byte of EM was set to a value other
than 0x00, and verify that the erroneous input is detected and that the decryption
operation exits with an error code.
Test FCS_COP.1/KeyEncap:3:
The evaluator shall decrypt each cipher text, C, produced by the RSA-OAEP
encryption operation of the TOE using RSADP, and perform the OAEP decoding
operation (described in NIST SP 800-56B section 7.2.2.4) to recover HA’ || X. For
each HA’, the evaluator shall take the corresponding A and the specified hash
algorithm and verify that HA' = Hash(A). The evaluator shall also force the TOE
to perform some RSA-OAEP decryptions where the A value is passed incorrectly,
and the evaluator shall verify that an error is detected.
Test FCS_COP.1/KeyEncap:4:
The evaluator shall check the format of the ‘X’ string recovered in OAEP.Test.3
to ensure that the format is of the form PS || 01 || K, where PS consists of zero or
more consecutive 0x00 bytes and K is the transported keying material. The
evaluator shall also feed into the TOE’s RSA-OEAP decryption operation some
cipher texts for which the resulting ‘X’ strings do not have the correct format (i.e.,
the leftmost non-zero byte is not 0x01). These incorrectly formatted ‘X’ variables
shall be detected by the RSA-OEAP decrypt function.
Test FCS_COP.1/KeyEncap:5:
The evaluator shall trigger all detectable decryption errors and validate that the
returned error codes are the same and that no information is given back to the
sender on which type of error occurred. The evaluator shall also validate that no
intermediate results from the TOE’s receiver-side operations are revealed to the
sender.
If the KTS-KEM-KWS scheme was selected, the evaluator shall perform the following
tests:
Test FCS_COP.1/KeyEncap:6:
The evaluator shall inspect each cipher text, C, produced by RSA-KEM-KWS
encryption operation of the TOE and make sure the length (in bytes) of the cipher
text, cLen, is greater than nLen (the length, in bytes, of the modulus of the RSA
public key) and that cLen - nLen is consistent with the byte lengths supported by
the key wrapping algorithm. The evaluator shall feed into the RSA-KEM-KWS
decryption operation a cipher text of unsupported length and verify that an error
is detected and that the decryption process stops.
Test FCS_COP.1/KeyEncap:7:
The evaluator shall separate the cipher text, C, produced by the sender-side of the
TOE into its C0 and C1 components and use the RSA decryption primitive to
recover the secret value, Z, from C0. The evaluator shall check that the unsigned
integer represented by Z is greater than 1 and less than n-1, where n is the modulus
of the RSA public key. The evaluator shall construct examples where the cipher
text is created with a secret value Z = 1 and make sure the RSA-KEM-KWS
decryption process detects the error. Similarly, the evaluator shall construct
examples where the cipher text is created with a secret value Z = n – 1 and make
sure the RSA-KEM-KWS decryption process detects the error.
Test FCS_COP.1/KeyEncap:8:
The evaluator shall attempt to successfully recover the secret value Z, derive the
key wrapping key, KWK, and unwrap the KWA-cipher text following the RSAKEM-KWS
decryption process given in NIST SP 800-56B section 7.2.3.4. If the
key-wrapping algorithm is AES-CCM, the evaluator shall verify that the value of
any (unwrapped) associated data, A, that was passed with the wrapped keying
material is correct The evaluator shall feed into the TOE’s RSA-KEM-KWS
decryption operation examples of incorrect cipher text and verify that a decryption
error is detected. If the key-wrapping algorithm is AES-CCM, the evaluator shall
attempt at least one decryption where the wrong value of A is given to the RSAKEM-KWS decryption operation and verify that a decryption error is detected. Similarly, if the key-wrapping algorithm is AES-CCM, the evaluator shall attempt
at least one decryption where the wrong nonce is given to the RSA-KEM-KWS
decryption operation and verify that a decryption error is detected.
Test FCS_COP.1/KeyEncap:9:
The evaluator shall trigger all detectable decryption errors and validate that the
resulting error codes are the same and that no information is given back to the
sender on which type of error occurred. The evaluator shall also validate that no
intermediate results from the TOE’s receiver-side operations (in particular, no Z
values) are revealed to the sender.
The TSF shall perform [key wrapping] in accordance with a specified cryptographic algorithm [AES] in the following modes [selection: KW, KWP, GCM, CCM] and cryptographic key size [selection: 128 bits, 256 bits] that meet the following: [AES as specified in ISO/IEC 18033-3, [selection: NIST SP 800-38F, ISO/IEC 19772, no other standards]].
Application
Note:
This requirement is used in the body of the ST if the ST author chooses to use key wrapping in the key chaining approach that is specified in
FCS_KYC_EXT.1.
This SFR is required when the TSF performs key wrapping as part of maintaining and deriving a key chain (FCS_KDF_EXT.1, FCS_KYC_EXT.1) or
when the TSF performs validation of a submask, intermediate key, or BEV using a key wrap operation (FCS_VAL_EXT.1).
The evaluator shall verify the TSS includes a description of the key wrap functions
and shall verify the key wrap uses an approved key wrap algorithm according to the
appropriate specification.
Guidance
There are no AGD evaluation activities for this SFR.
The TSF shall perform [data encryption and decryption] in accordance with a specified cryptographic algorithm [AES used in
[selection: CBC, GCM, XTS]
mode] and cryptographic key sizes
[selection: 128 bits, 256 bits] that meet the following: [AES as specified in ISO /IEC 18033-3,
[selection: CBC as specified in ISO/IEC 10116, GCM as specified in ISO/IEC 19772, XTS as specified in IEEE 1619]].
Application
Note:
The intent of this requirement in the context of this cPP is to provide an SFR that expresses the appropriate symmetric encryption/decryption algorithms
suitable for use in the TOE. If the ST author incorporates the validation requirement (FCS_VAL_EXT.1) and chooses to select the option to decrypt a known
value and perform a comparison, this is the requirement used to specify the algorithm, modes, and key sizes the ST author can choose from.
When the XTS mode is selected, a cryptographic key of 256-bit or of 512-bit is allowed as specified in IEEE 1619. XTS-AES key is divided into two AES keys
of equal size - for example, AES-128 is used as the underlying algorithm, when 256-bit key and XTS mode are selected. AES-256 is used when a 512-bit key
and XTS mode are selected.
This SFR is required when the TSF performs any key wrapping, key encryption, or key derivation operation as part of maintaining and deriving a key chain
(FCS_KDF_EXT.1, FCS_KYC_EXT.1), or when the TSF performs validation of a submask, intermediate key, or BEV using a symmetric encryption operation
(FCS_VAL_EXT.1).
The evaluator shall verify the TSS includes a description of the key size used for
encryption and the mode used for encryption.
Guidance
If multiple encryption modes are supported, the evaluator examines the guidance
documentation to determine that the method of choosing a specific mode/key size by
the end user is described.
For the AES-CBC tests described below, the plaintext, ciphertext, and IV values shall
consist of 128-bit blocks. To determine correctness, the evaluator shall compare the
resulting values to those obtained by submitting the same inputs to a known-good
implementation.
These tests are intended to be equivalent to those described in NIST’s AES Algorithm
Validation Suite (AESAVS)
(http://csrc.nist.gov/groups/STM/cavp/documents/aes/AESAVS.pdf). Known answer
values tailored to exercise the AES-CBC implementation can be obtained using NIST’s
CAVS Algorithm Validation Tool or from NIST’s ACPV service for automated
algorithm tests (acvp.nist.gov), when available. It is not recommended that evaluators
use values obtained from static sources such as the example NIST’s AES Known
Answer Test Values from the AESAVS document, or use values not generated
expressly to exercise the AES-CBC implementation.
To test the encrypt functionality of AES-CBC, the evaluator shall supply a set of five
different plaintext values for each selected key size and obtain the ciphertext value that
results from AES-CBC encryption of the given plaintext using a key value of all zeros
and an IV of all zeros.
To test the decrypt functionality of AES-CBC, the evaluator shall supply a set of five
different ciphertext values for each selected key size and obtain the plaintext value that
results from AES-CBC decryption of the given ciphertext using a key value of all zeros
and an IV of all zeros.
KAT-2 (KeySBox):
To test the encrypt functionality of AES-CBC, the evaluator shall supply a set of five
different key values for each selected key size and obtain the ciphertext value that
results from AES-CBC encryption of an all-zeros plaintext using the given key value
and an IV of all zeros.
To test the decrypt functionality of AES-CBC, the evaluator shall supply a set of five
different key values for each selected key size and obtain the plaintext that results from
AES-CBC decryption of an all-zeros ciphertext using the given key and an IV of all
zeros.
KAT-3 (Variable Key):
To test the encrypt functionality of AES-CBC, the evaluator shall supply a set of keys
for each selected key size (as described below) and obtain the ciphertext value that
results from AES encryption of an all-zeros plaintext using each key and an IV of all
zeros.
Key i in each set shall have the leftmost i bits set to ones and the remaining bits to
zeros, for values of i from 1 to the key size. The keys and corresponding ciphertext are
listed in AESAVS, Appendix E.
To test the decrypt functionality of AES-CBC, the evaluator shall use the same keys as
above to decrypt the ciphertext results from above. Each decryption should result in an
all-zeros plaintext.
KAT-4 (Variable Text):
To test the encrypt functionality of AES-CBC, for each selected key size, the evaluator
shall supply a set of 128-bit plaintext values (as described below) and obtain the
ciphertext values that result from AES-CBC encryption of each plaintext value using a
key of each size and IV consisting of all zeros.
Plaintext value i shall have the leftmost i bits set to ones and the remaining bits set to
zeros, for values of i from 1 to 128. The plaintext values are listed in AESAVS,
Appendix D.
To test the decrypt functionality of AES-CBC, for each selected key size, use the
plaintext values from above as ciphertext input, and AES-CBC decrypt each ciphertext
value using key of each size consisting of all zeros and an IV of all zeros.
The evaluator shall test the encrypt functionality by encrypting nine i-block messages
for each selected key size, for 2 ≤ i ≤ 10. For each test, the evaluator shall supply a key,
an IV, and a plaintext message of length i blocks, and encrypt the message
using AES-CBC. The resulting ciphertext values shall be compared to the results of encrypting the
plaintext messages using a known good implementation
The evaluator shall test the decrypt functionality by decrypting nine i-block messages
for each selected key size, for 2 ≤ i ≤ 10. For each test, the evaluator shall supply a key,
an IV, and a ciphertext message of length i blocks, and decrypt the message
using AES-CBC. The resulting plaintext values shall be compared to the results of decrypting the
ciphertext messages using a known good implementation.
The evaluator shall test the encrypt functionality for each selected key size using 100
3-tuples of pseudo-random values for plaintext, IVs, and keys.
The evaluator shall supply a single 3-tuple of pseudo-random values for each selected
key size. This 3-tuple of plaintext, IV, and key is provided as input to the below
algorithm to generate the remaining 99 3-tuples, and to run each 3-tuple through 1000
iterations of AES-CBC encryption.
# Input: PT, IV, Key
Key[0] = Key
IV[0] = IV PT[0] = PT
for i = 1 to 100 {
Output Key[i], IV[i], PT[0]
for j = 1 to 1000 {
if j == 1 {
CT[1] = AES-CBC-Encrypt(Key[i], IV[i], PT[1])
PT[2] = IV[i]
} else {
CT[j] = AES-CBC-Encrypt(Key[i], PT[j])
PT[j+1] = CT[j-1]
}
}
Output CT[1000]
The ciphertext computed in the 1000th iteration (CT[1000]) is the result for each of the
100 3-tuples for each selected key size. This result shall be compared to the result of
running 1000 iterations with the same values using a known good implementation.
The evaluator shall test the decrypt functionality using the same test as above,
exchanging CT and PT, and replacing AES-CBC-Encrypt with AES-CBC-Decrypt.
The evaluator shall test the authenticated encrypt functionality of AES-GCM for each
combination of the following input parameter lengths:
128 bit and 256 bit keys
Two plaintext lengths. One of the plaintext lengths shall be a non-zero integer multiple of 128 bits, if supported. The other plaintext length shall not be an integer multiple of 128 bits, if supported.
Three AAD lengths. One AAD length shall be 0, if supported. One AAD length
shall be a non-zero integer multiple of 128 bits, if supported. One AAD length shall
not be an integer multiple of 128 bits, if supported.
Two IV lengths. If 96 bit IV is supported, 96 bits shall be one of the two IV lengths
tested.
The evaluator shall test the encrypt functionality using a set of 10 key, plaintext, AAD,
and IV tuples for each combination of parameter lengths above and obtain the
ciphertext value and tag that results from AES-GCM authenticated encrypt. Each
supported tag length shall be tested at least once per set of 10. The IV value may be
supplied by the evaluator or the implementation being tested, as long as it is known.
The evaluator shall test the decrypt functionality using a set of 10 key, ciphertext, tag,
AAD, and IV 5-tuples for each combination of parameter lengths above and obtain a
Pass/Fail result on authentication and the decrypted plaintext if Pass. The set shall
include five tuples that Pass and five that Fail.
The results from each test may either be obtained by the evaluator directly or by
supplying the inputs to the implementer and receiving the results in response. To
determine correctness, the evaluator shall compare the resulting values to those
obtained by submitting the same inputs to a known good implementation.
The evaluator shall test the encrypt functionality of XTS-AES for each combination of
the following input parameter lengths:
256 bit (for AES-128) and 512 bit (for AES-256) keys
Three data unit (i.e., plaintext) lengths. One of the data unit lengths shall be a
non-zero integer multiple of 128 bits, if supported. One of the data unit lengths
shall be an integer multiple of 128 bits, if supported. The third data unit length shall
be either the longest supported data unit length or 216 bits, whichever is smaller.
using a set of 100 (key, plaintext and 128-bit random tweak value) 3-tuples and obtain
the ciphertext that results from XTS-AES encrypt.
The evaluator may supply a data unit sequence number instead of the tweak value if
the implementation supports it. The data unit sequence number is a base-10 number
ranging between 0 and 255 that implementations convert to a tweak value internally
The evaluator shall test the decrypt functionality of XTS-AES using the same test as
for encrypt, replacing plaintext values with ciphertext values and XTS-AES encrypt
with XTS-AES decrypt.
FCS_KDF_EXT.1 Cryptographic Key Derivation
The inclusion of this selection-based component depends upon selection in
FCS_KYC_EXT.1.1.
The TSF shall accept [selection: an RNG generated submask as specified in FCS_RBG.1, a conditioned password submask, imported submask] to derive an intermediate key, as defined in [selection:
NIST SP 800-108 [selection: KDF in Counter Mode, KDF in Feedback Mode, KDF in Double-Pipeline Iteration Mode]
] using the keyed-hash functions specified in FCS_COP.1/KeyedHash, such that the output is at least of equivalent security strength (in number of bits) to the BEV.
Application
Note:
This requirement is used in the body of the ST if the ST author chooses to use key derivation in the key chaining approach that is specified in FCS_KYC_EXT.1.
This requirement establishes acceptable methods for generating a new random key or an existing submask to create a new key along the key chain.
The evaluator shall verify the TSS includes a description of the key derivation function
and shall verify the key derivation uses an approved derivation mode and key expansion
algorithm according to SP 800-108 and SP 800-132.
Guidance
There are no AGD evaluation activities for this SFR.
The evaluator shall examine the vendor’s KMD to ensure that all keys used are derived
using an approved method and a description of how and when the keys are derived.
Tests
There are no test evaluation activities for this SFR.
FCS_PCC_EXT.1 Cryptographic Password Construction and Conditioning
The inclusion of this selection-based component depends upon selection in
FCS_AFA_EXT.1.1.
A password used by the TSF to generate a password authorization factor shall
enable at least [assignment:
positive integer of 64 or more] characters in the set of {upper case characters, lower case characters, numbers, and [assignment:
other supported special characters]} and shall perform Password-based Key Derivation Functions in accordance with a specified cryptographic algorithm HMAC-[selection: SHA-256, SHA384, SHA-512], with
[selection: [assignment:
positive integer of 1000 or more] iterations, [assignment:
positive integer of one or more] and
[assignment:
positive integer of 10000 or more] subsequent rounds
of AES operations with a device key and PBKDF2 output per FCS_COP.1/KeyEnc or
FCS_COP.1/KeyEncap] and output cryptographic key sizes
[selection: 128 bits, 256 bits] that meet the following: [NIST SP 800-132].
Application
Note:
The password is represented on the host machine as a sequence of characters whose encoding depends on the TOE and the
underlying OS. This sequence must be conditioned into a string of bits that forms the submask to be used as input into
the key chain. Conditioning can be performed using one of the identified hash functions or the process described in
NIST SP 800-132; the method used is selected by the ST author. If 800-132 conditioning is specified, then the ST
author fills in the number of iterations that are performed. 800-132 also requires the use of a pseudo-random
function (PRF) consisting of HMAC with an approved hash function. The ST author selects the hash function used which
also includes the appropriate requirements for HMAC.
This SFR is claimed when password conditioning is used to derive a submask from a password authentication factor,
as defined in FCS_AFA_EXT.1.1.
The evaluator shall ensure the TSS describes the manner in which the TOE enforces
the construction of passwords, including the length, and requirements on characters
(number and type). The evaluator also verifies that the TSS provides a description of
how the password is conditioned and the evaluator ensures it satisfies the requirement.
Guidance
There are no AGD evaluation activities for this SFR.
The evaluator shall examine the KMD to ensure that the formation of the BEV and
intermediary keys is described and that the key sizes match that selected by the ST
author.
The evaluator shall check that the KMD describes the method by which the
passwords and passphrase is first encoded and then fed to the SHA algorithm. The settings
for the algorithm (padding, blocking, etc.) shall be described, and the evaluator shall
verify that these are supported by the selections in this component as well as the
selections concerning the hash function itself. The evaluator shall verify that the KMD
contains a description of how the output of the hash function is used to form the
submask that will be input into the function and is the same length as the BEV as
specified above.
Tests
The evaluator shall also perform the following tests:
Test FCS_PCC_EXT.1:1:
Ensure that the TOE supports passwords/passphrases of a minimum
length of 64 characters.
Test FCS_PCC_EXT.1:2:
If the TOE supports a passwords and passphrase length up to a maximum
number of characters, n (which would be greater than 64), then ensure that the
TOE will not accept more than n characters.
Test FCS_PCC_EXT.1:3:
Ensure that the TOE supports passwords consisting of all characters
assigned and supported by the ST author.
FCS_RBG.1 Cryptographic Operation (Random Bit Generation)
The TSF shall perform deterministic random bit generation services using
[selection: Hash_DRBG (any), HMAC_DRBG (any), CTR_DRBG (AES)] in accordance with [selection: ISO/IEC 18031:2011, NIST SP 800-90A] after initialization with a seed.
The TSF shall use a [selection: TSF noise source [assignment:
name of noise source], multiple TSF noise sources [assignment:
names of noise sources], TSF interface for seeding]
for initialized seeding.
Application
Note:
For the
selection in this requirement, the ST author selects "TSF noise source" if
a single noise source is used as input to the DRBG. The ST author selects "multiple TSF noise sources" if a seed is formed from a combination of two or more noise sources within the TOE boundary. If the TSF implements two or more separate DRBGs that are seeded in separate manners, this SFR should be iterated for each DRBG. It multiple distinct noise sources exist such that each DRBG only uses one of them, then each iteration would select "TSF noise source"; "multiple TSF noise sources" is only selected if a single DRBG uses multiple noise sources for its seed. The ST author selects "TSF interface for seeding" if noise source data is generated outside the TOE boundary.
If "TSF noise source" is selected, FCS_RBG.3 must be claimed.
The TSF shall update the RBG state by [selection: reseeding, uninstantiating and reinstantiating] using a [selection: TSF noise source [assignment:
name of noise source], TSF interface for seeding]
in the following situations: [selection:
never
on demand
on the condition: [assignment:
condition]
after [assignment:
time]
]
in accordance with [assignment:
list of standards].
The evaluator shall verify that the TSS identifies the DRBGs used by the TOE.
Guidance
If the DRBG functionality is configurable, the evaluator shall verify that the operational guidance includes instructions on how to configure this behavior.
Tests
The evaluator shall perform the following tests:
The evaluator shall perform 15 trials for the DRBG implementation. If the DRBG
is configurable, the evaluator shall perform 15 trials for each configuration. The
evaluator shall also confirm that the operational guidance contains appropriate
instructions for configuring the DRBG functionality.
If the DRBG has prediction resistance enabled, each trial consists of (1) instantiate DRBG, (2)
generate the first block of random bits (3) generate a second block of random bits
(4) uninstantiate. The evaluator verifies that the second block of random bits is
the expected value. The evaluator shall generate eight input values for each
trial. The first is a count (0 – 14). The next three are entropy input, nonce, and
personalization string for the instantiate operation. The next two are additional
input and entropy input for the first call to generate. The final two are
additional input and entropy input for the second call to generate. These values
are randomly generated. "generate one block of random bits" means to generate
random bits with number of returned bits equal to the Output Block Length (as
defined in NIST SP 800-90A).
If the DRBG does not have prediction resistance,
each trial consists of (1) instantiate DRBG, (2) generate the first block of
random bits (3) reseed, (4) generate a second block of random bits (5)
uninstantiate. The evaluator verifies that the second block of random bits is the
expected value. The evaluator shall generate eight input values for each trial. The first is a count (0 – 14). The next three are entropy input, nonce, and
personalization string for the instantiate operation. The fifth value is
additional input to the first call to generate. The sixth and seventh are
additional input and entropy input to the call to reseed. The final value is
additional input to the second generate call.
The following list contains more information on some of the input values to be generated/selected by the evaluator.
Entropy input: The length of the entropy input value must equal the seed
length.
Nonce: If a nonce is supported (CTR_DRBG with no Derivation Function does
not use a nonce), the nonce bit length is one-half the seed length.
Personalization string: The length of the personalization string must be
less than or equal to seed length. If the implementation only supports one
personalization string length, then the same length can be used for both values. If more than one string length is support, the evaluator shall use personalization
strings of two different lengths. If the implementation does not use a
personalization string, no value needs to be supplied.
Additional input: The additional input bit lengths have the same defaults
and restrictions as the personalization string lengths.
Documentation will be produced - and the evaluator shall perform the
activities - in accordance with Appendix D, "Entropy Documentation and
Assessment" and the ,
Clarification to the Entropy Documentation and Assessment Annex.
The evaluator shall verify that the TSS identifies how the DRBG state is updated, and the situations under which this may occur.
Guidance
If the ST claims that the DRBG state can be updated on demand, the evaluator shall verify that the operational guidance has instructions for how to perform this operation.
The TSF shall be able to accept a minimum input of [assignment:
minimum input length greater than zero] from a TSF interface for the purpose of seeding.
Application
Note:
This requirement is claimed when a DRBG is seeded with entropy from one or more noise source that is outside the TOE
boundary. Typically the entropy produced by an environmental noise source is conditioned such that the input length has
full entropy and is therefore usable as the seed. However, if this is not the case, it should be noted what the minimum
entropy rate of the noise source is so that the TSF can collect a sufficiently large sample of noise data to be
conditioned into a seed value.
The evaluator shall examine the entropy documentation required by FCS_RBG.1.2 to verify that it identifies, for each DRBG function implemented by the TOE, the TSF external interface used to seed the TOE's DRBG. The evaluator shall verify that this includes the amount of sampled data and the min-entropy rate of the sampled data such that it can be determined that sufficient entropy can be made available for the highest strength keys that the TSF can generate (e.g., 256 bits). If the seed data cannot be assumed to have full entropy (e.g., the min-entropy of the sampled bits is less than 1), the evaluator shall ensure that the entropy documentation describes the method by which the TOE estimates the amount of entropy that has been accumulated to ensure that sufficient data is collected and any conditioning that the TSF applies to the output data to create a seed of sufficient size with full entropy.
The TSF shall be able to seed the RBG using a [selection, choose one of: TSF software-based noise source, TSF hardware-based noise source] [assignment:
name of noise source] with a minimum of [assignment:
number of bits] bits of min-entropy.
Application
Note:
This requirement is claimed when a DRBG is seeded with entropy from a single noise source that is within the TOE boundary. Min-entropy should be expressed as a ratio of entropy bits to sampled bits so that the total amount of data needed to ensure full entropy is known, as well as the conditioning function by which that data is reduced in size to the seed.
The evaluator shall examine the entropy documentation required by FCS_RBG.1.2 to verify that it identifies, for each DRBG function implemented by the TOE, the TSF noise source used to seed the TOE's DRBG. The evaluator shall verify that this includes the amount of sampled data and the min-entropy rate of the sampled data such that it can be determined that sufficient entropy can be made available for the highest strength keys that the TSF can generate (e.g., 256 bits). If the seed data cannot be assumed to have full entropy (e.g., the min-entropy of the sampled bits is less than 1), the evaluator shall ensure that the entropy documentation describes the method by which the TOE estimates the amount of entropy that has been accumulated to ensure that sufficient data is collected and any conditioning that the TSF applies to the output data to create a seed of sufficient size with full entropy.
The TSF shall be able to seed the RBG using [selection: [assignment:
number] TSF software-based noise sources, [assignment:
number] TSF hardware-based noise sources].
Application
Note:
This requirement is claimed when a DRBG is seeded with entropy from multiple noise sources that are within the TOE boundary. FCS_RBG.5 defines the mechanism by which these sources are combined to ensure sufficient minimum entropy.
The evaluator shall examine the entropy documentation required by FCS_RBG.1.2 to verify that it identifies, for each DRBG function implemented by the TOE, each TSF noise source used to seed the TOE's DRBG. The evaluator shall verify that this includes the amount of sampled data and the min-entropy rate of the sampled data from each data source.
The TSF shall [assignment:
combining operation] [selection: output from TSF noise sources, input from TSF interfaces for seeding)] to create the entropy input into the derivation function as defined in [assignment:
list of standards], resulting in a minimum of [assignment:
number of bits] bits of min-entropy.
Application
Note:
Examples of typical combining operations include, but are not limited to, XORing or hashing.
Using the entropy sources specified in FCS_RBG.4, the evaluator shall examine the entropy documentation required by FCS_RBG.1.2 to verify that it describes the method by which the various entropy sources are combined into a single seed. This should include an estimation of the rate at which each noise source outputs data and whether this is dependent on any system-specific factors so that each source's relative contribution to the overall entropy is understood. The evaluator shall verify that the resulting combination of sampled data and the min-entropy rate of the sampled data is described in sufficient detail to determine that sufficient entropy can be made available for the highest strength keys that the TSF can generate (e.g., 256 bits). If the seed data cannot be assumed to have full entropy (e.g., the min-entropy of the sampled bits is less than 1), the evaluator shall ensure that the entropy documentation describes the method by which the TOE estimates the amount of entropy that has been accumulated to ensure that sufficient data is collected and any conditioning that the TSF applies to the output data to create a seed of sufficient size with full entropy.
The TSF shall combine submasks using the following method [selection: exclusive OR (XOR), SHA-256, SHA-384, SHA-521] to generate an [intermediary key or BEV].
Application
Note:
This requirement specifies the way that a product may combine the various submasks by using either an XOR or an
approved SHA-hash. The approved hash functions are captured in
FCS_COP.1/Hash.
This SFR is claimed when the TSF requires the use of submask combining as part of maintaining or deriving a key chain.
If the submasks produced from the authorization factors are XORed together to form
the BEV or intermediate key, the TSS section shall identify how this is performed (e.g.,
if there are ordering requirements, checks performed, etc.). The evaluator shall also
confirm that the TSS describes how the length of the output produced is at least the
same as that of the BEV.
Guidance
There are no AGD evaluation activities for this SFR.
The evaluator shall review the KMD to ensure that an approved combination is used
and does not result in the weakening or exposure of key material.
Tests
The evaluator shall perform the following test:
Test FCS_SMC_EXT.1:1:
(conditional): If there is more than one authorization factor, ensure that failure
to supply a required authorization factor does not result in access to the encrypted data.
FCS_VAL_EXT.1 Validation
The inclusion of this selection-based component depends upon selection in
FCS_KYC_EXT.1.2.
The TSF shall perform validation of the [selection: submask, intermediate key, BEV]
using the following methods: [selection:
key wrap as specified in FCS_COP.1/KeyWrap;
hash the [selection: submask, intermediate key, BEV]
as specified in [selection: FCS_COP.1/Hash, FCS_COP.1/KeyedHash] and compare it to a stored hashed [selection: submask, intermediate key, BEV];
decrypt a known value using the [selection: submask, intermediate key, BEV] specified in FCS_COP.1/SKC and compare it against a stored known value
The TSF shall require validation of the [BEV] prior to [forwarding the BEV to the EE].
Application
Note:
This SFR is claimed when the TSF validates an authentication factor as a prerequisite to unlocking the key chain as
defined in FCS_KYC_EXT.1.
perform a key sanitization of the DEK upon a
[selection: configurable number, [assignment:
ST author specified number]]
of consecutive failed validation attempts
institute a delay such that only [assignment:
ST author specified number of attempts] can be made within a 24 hour period
block validation after [assignment:
ST author specified number of attempts] of consecutive failed validation attempts
require power cycle or reset the TOE after [assignment:
ST author specified number of attempts] of consecutive failed validation attempts
The purpose of performing secure validation is to not expose any material that might compromise the submasks. For the selections in FCS_VAL_EXT.1.1, the ST author must clarify in the KMD which specific entities are referred to in this SFR if multiple entities of a type exist.
The TOE validates the submasks (e.g., authorization factors) prior to presenting the BEV to the EE. When a password is used as an authorization factor, it is conditioned before any attempts to validate. In cases where validation of the authorization factors fails, the product will not forward a BEV to EE.
When the key wrap in FCS_COP.1/KeyWrap is used, the validation is performed inherently.
The delay must be enforced by the TOE, but this requirement is not intended to address attacks that bypass the product (e.g. attacker obtains hash value or “known” crypto value and mounts attacks outside of the TOE, such as a third party password crackers). The cryptographic functions (i.e., hash, decryption) performed are those specified in FCS_COP.1/Hash, FCS_COP.1/KeyedHash, and FCS_COP.1/SKC.
The ST author may need to iterate this requirement if multiple authentication factors are used, and either different methods are used to validate, or in some cases one or more authentication factors may be validated, and one or more are not validated.
The evaluator shall examine the TSS to determine which authorization factors support
validation.
The evaluator shall examine the TSS to review a high-level description if multiple
submasks are used within the TOE, how the submasks are validated (e.g., each submask
validated before combining, once combined validation takes place).
Guidance
(conditional) If the validation functionality is configurable, the evaluator shall examine
the operational guidance to ensure it describes how to configure the TOE to ensure the
limits regarding validation attempts can be established.
(conditional) If the validation functionality is specified by the ST author, the evaluator
shall examine the operational guidance to ensure that it states the values that the TOE
uses for limits regarding validation attempts.
The evaluator shall examine the KMD to verify that it described the method the TOE
employs to limit the number of consecutively failed authorization attempts.
The evaluator shall examine the vendor’s KMD to ensure it describes how validation
is performed. The description of the validation process in the KMD provides detailed
information how the TOE validates the submasks. The KMD describes how the process
works, such that it does not expose any material that might compromise the submasks.
Tests
The evaluator shall perform the following tests:
Test FCS_VAL_EXT.1.1:1:
The evaluator shall determine the limit on the average rate of the number of
consecutive failed authorization attempts. The evaluator will test the TOE by entering
that number of incorrect authorization factors in consecutive attempts to access the
protected data. If the limit mechanism includes any “lockout” period, the time period
tested should include at least one such period. Then the evaluator will verify that the
TOE behaves as described in the TSS.
Test FCS_VAL_EXT.1.1:2:
For each validated authorization factor, ensure that when the user provides an
incorrect authorization factor, the TOE prevents the BEV from being forwarded outside
the TOE (e.g., to the EE).
B.2 Protection of the TSF (FPT)
FPT_FLS.1 Failure with Preservation of Secure State
The inclusion of this selection-based component depends upon selection in
FCS_RBG.1.2.
The TSF shall preserve a secure state when the following types of failures occur: [DRBG self-test failure].
Application
Note:
The intent of this requirement is to ensure that cryptographic services requiring random bit generation cannot be performed if a failure of a self-test defined in FPT_TST.1 occurs.
The evaluator shall verify that the TSF describes how the TOE enters an error state in the event of a DRBG self-test failure.
Guidance
The evaluator shall verify that the guidance documentation describes the error state that results from a DRBG self-test failure and the actions that a user or administrator should take in response to attempt to resolve the error state.
The TSF shall run a suite of the following self-tests [selection: during initial start-up, periodically during normal operation, at the request of the authorized user, at the conditions [assignment:
conditions under which self-test should occur]]
to demonstrate the correct operation of [selection: [assignment:
parts of TSF], TSF data].
The TSF shall provide authorized users with the capability to verify the integrity of [selection: [assignment:
parts of TSF], TSF].
Application
Note:
This SFR is a required dependency of FCS_RBG.1. It is intended to require that any DRBG implemented by the TOE undergo health testing to ensure that the random bit generation functionality has not been degraded. If the TSF supports multiple DRBGs, this SFR should be iterated to describe the self-test behavior for each.
The evaluator shall examine the TSS to ensure that it details the self-tests that are run by the TSF along with how they are run. This description should include an outline of what the tests are actually doing. The evaluator shall ensure that the TSS makes an argument that the tests are sufficient to demonstrate that the DRBG is operating correctly.
Note that this information may also be placed in the entropy documentation specified by .
Guidance
If a self-test can be executed at the request of an authorized user, the evaluator shall verify that the operational guidance provides instructions on how to execute that self-test.
Tests
For each self-test, the evaluator shall verify that evidence is produced that the self-test is executed when specified by FPT_TST.1.1.
If a self-test can be executed at the request of an authorized user, the evaluator shall verify that following the steps documented in the operational guidance to perform the self-test will result in execution of the self-test.
Appendix C - Extended Component Definitions
This appendix contains the definitions for all extended requirements specified in the PP.
C.1 Extended Components Table
All extended components specified in the PP are listed in this table:
Table 5: Extended Component Definitions
Functional Class
Functional Components
Cryptographic Support (FCS)
FCS_AFA_EXT Authorization Factor Acquisition FCS_KDF_EXT Cryptographic Key Derivation FCS_KYC_EXT Key Chaining FCS_PCC_EXT Cryptographic Password Construction and Conditioning FCS_SMC_EXT Submask Combining FCS_SNI_EXT Cryptographic Operation (Salt, Nonce, and Initialization Vector Generation) FCS_VAL_EXT Validation of Cryptographic Elements
The TSF shall accept the following authorization factors: [selection:
a submask derived from a password authorization factor conditioned as defined in FCS_PCC_EXT.1,
an external smart card factor that is protecting a submask that is
[selection: generated by the TOE (using the RBG as specified in FCS_RBG.1), generated by the Host Platform]
protected using [selection:
ECC schemes using "NIST curves" of [selection: P-256, P-384, P-521]
]
with user presence proved by presentation of the smart card and [selection: none, an OE defined PIN, a configurable PIN],
an external USB token factor that is at least the same security strength as the BEV, and is protecting a submask generated by the TOE, using the RBG as specified in FCS_RBG.1,
an external USB token factor that is at least the same security strength as the BEV, and is protecting a submask generated by the Host Platform
The TSF shall reacquire the authorization factors specified in FCS_AFA_EXT.1
upon transition from any compliant power saving state specified in FPT_PWR_EXT.1 prior to permitting access to plaintext data.
C.2.1.2 FCS_KDF_EXT Cryptographic Key Derivation
Family Behavior
This family specifies the means by which an intermediate key is derived from a specified set of submasks.
Component Leveling
FCS_KDF_EXT.1,
Cryptographic Key Derivation,
requires the TSF to derive intermediate keys from submasks using the specified hash functions.
The TSF shall accept [selection: an RNG generated submask as specified in FCS_RBG.1, a conditioned password submask, imported submask] to derive an intermediate key, as defined in [selection:
NIST SP 800-108 [selection: KDF in Counter Mode, KDF in Feedback Mode, KDF in Double-Pipeline Iteration Mode]
] using the keyed-hash functions specified in FCS_COP.1, such that the output is at least of equivalent security strength (in number of bits) to the BEV.
C.2.1.3 FCS_KYC_EXT Key Chaining
Family Behavior
This family provides the specification to be used for using multiple layers of encryption keys to ultimately secure the protected data encrypted on the drive.
Component Leveling
FCS_KYC_EXT.1,
Key Chaining (Initiator),
requires the TSF to maintain a key chain for a BEV that is provided to a component external to the TOE.
FCS_KYC_EXT.2,
Key Chaining (Recipient) ,
requires the TSF to be able to accept a BEV that is then chained to a DEK used
by the TSF through some method.
Note that this cPP does not include FCS_KYC_EXT.2; it is only included here to provide a complete definition of the FCS_KYC_EXT family.
]
while maintaining an effective strength of
[selection: 128 bits, 256 bits] for symmetric keys and an effective strength of
[selection: not applicable, 112 bits, 128 bits, 192 bits, 256 bits] for asymmetric keys.
FCS_KYC_EXT.1.2
The TSF shall provide at least a
[selection: 128 bits, 256 bits] BEV to [assignment:
one or more external entities]
[selection:
after the TSF has successfully performed the validation process as specified in FCS_VAL_EXT.1
] while maintaining an effective strength of [selection: 128 bits, 256 bits]
while maintaining an effective strength of [selection: 128 bits, 256 bits] for symmetric keys and an effective strength of [selection: not applicable, 112 bits, 128 bits, 192 bits, 256 bits] for asymmetric keys.
C.2.1.4 FCS_PCC_EXT Cryptographic Password Construction and Conditioning
Family Behavior
This family ensures that passwords used to produce the BEV are robust (in terms of their composition) and are conditioned to provide an appropriate-length bit string.
Component Leveling
FCS_PCC_EXT.1,
Cryptographic Password Construction and Conditioning,
requires the TSF to accept passwords of a certain composition and condition them appropriately.
A password used by the TSF to generate a password authorization factor shall
enable at least [assignment:
positive integer of 64 or more] characters in the set of {upper case characters, lower case characters, numbers, and [assignment:
other supported special characters]} and shall perform Password-based Key Derivation Functions in accordance with a specified cryptographic algorithm HMAC-[selection: SHA-256, SHA384, SHA-512], with
[selection: [assignment:
positive integer of 1000 or more] iterations, [assignment:
positive integer of one or more] and [assignment:
positive integer of 10000 or more] subsequent rounds of AES operations with a device key and PBKDF2 output per FCS_COP.1 or FCS_COP.1] and output cryptographic key sizes
[selection: 128 bits, 256 bits] that meet the following: [assignment:
PBKDF recommendation or
specification].
C.2.1.5 FCS_SMC_EXT Submask Combining
Family Behavior
This family specifies the means by which submasks are combined, if the TOE supports more than one submask being used to derive or protect the BEV.
Component Leveling
FCS_SMC_EXT.1,
Submask Combining ,
requires the TSF to combine the submasks in a predictable fashion.
The TSF shall combine submasks using the following method [selection: exclusive OR (XOR), SHA-256, SHA-384, SHA-521] to generate an [assignment:
types of keys].
C.2.1.6 FCS_SNI_EXT Cryptographic Operation (Salt, Nonce, and Initialization Vector Generation)
Family Behavior
This family ensures that salts, nonces, and IVs are well formed.
Component Leveling
FCS_SNI_EXT.1,
Cryptographic Operation (Salt, Nonce, and Initialization Vector Generation),
requires the generation of salts, nonces, and IVs to be used by the cryptographic components of the TOE to be performed in the specified manner.
The TSF shall perform validation of the [selection: submask, intermediate key, BEV]
using the following methods: [selection:
key wrap as specified in FCS_COP.1;
hash the [selection: submask, intermediate key, BEV]
as specified in [assignment:
cryptographic operation requirement] and compare it to a stored hashed [selection: submask, intermediate key, BEV];
decrypt a known value using the [selection: submask, intermediate key, BEV] specified in FCS_COP.1 and compare it against a stored known value
perform a key sanitization of the DEK upon a
[selection: configurable number, [assignment:
ST author specified number]]
of consecutive failed validation attempts
institute a delay such that only [assignment:
ST author specified number of attempts] can be made within a 24 hour period
block validation after [assignment:
ST author specified number of attempts] of consecutive failed validation attempts
require power cycle or reset the TOE after [assignment:
ST author specified number of attempts] of consecutive failed validation attempts
This PP defines the following extended components as part of the
FPT class originally defined by CC Part 2:
C.2.2.1 FPT_KYP_EXT Key and Key Material Protection
Family Behavior
This family requires that key and key material be protected if and when written to non-volatile storage.
Component Leveling
FPT_KYP_EXT.1,
Protection of Key and Key Material ,
requires the TSF to ensure that no plaintext key or key material are written to non-volatile storage.
This family defines secure behavior of the TSF when the TOE supports multiple power saving states. The use of compliant power saving states (i.e. power saving states that purge security relevant data upon entry) is essential for ensuring that state transitions cannot be used as attack vectors to bypass TOE self-protection mechanisms.
Component Leveling
FPT_PWR_EXT.1,
Power Saving States,
defines the compliant power saving states that are implemented by the TSF.
FPT_PWR_EXT.2,
Timing of Power Saving States,
describes the situations that cause compliant power saving states to be entered.
Management: FPT_PWR_EXT.1
The following actions could be considered for the management functions in FMT:
Enable or disable the use of individual power saving states
Specify one or more power saving state configurations
The TSF shall define the following compliant power saving states: [selection, choose one of: S3, S4, G2(S5), G3, [assignment:
other power saving states]].
For each compliant power saving state defined in FPT_PWR_EXT.1.1, the TSF shall enter
the compliant power saving state when the following conditions occur: user-initiated request, [selection: shutdown, user inactivity, request initiated by remote management system, [assignment:
other conditions], no other conditions].
C.2.2.3 FPT_TUD_EXT Trusted Update
Family Behavior
Components in this family address the requirements for updating the TOE firmware and/or software.
Component Leveling
FPT_TUD_EXT.1,
Trusted Update,
requires the capability to be provided to update the TOE firmware and software, including the ability to verify the updates prior to installation.
Management: FPT_TUD_EXT.1
The following actions could be considered for the management functions in FMT:
Ability to update the TOE and to verify the updates
Audit: FPT_TUD_EXT.1
The following actions should be auditable if FAU_GEN Security audit data generation is included in the PP/ST:
The TSF shall provide [assignment:
list of subjects] the ability to
query the current version of the TOE
[selection: software, firmware].
FPT_TUD_EXT.1.2
The TSF shall provide [assignment:
list of subjects] the ability to initiate updates to TOE
[selection: software, firmware].
FPT_TUD_EXT.1.3
The TSF shall verify updates to the TOE software using a [selection: digital signature, published hash] by the manufacturer prior to installing those updates.
Appendix D - Entropy Documentation and Assessment
This is an optional appendix in the cPP, and only applies if the TOE is providing deterministic random bit generation services, e.g. the ST claims FCS_RBG.1.
This appendix describes the required supplementary information for each entropy source used by the TOE.
The documentation of the entropy sources should be detailed enough that, after reading, the evaluator will thoroughly understand the entropy source and why it can be relied upon to provide sufficient entropy. This documentation should include multiple detailed sections: design description, entropy justification, operating conditions, and health testing. This documentation is not required to be part of the TSS in the public facing ST.
D.1 Design Description
Documentation shall include the design of each entropy source as a whole, including the interaction of all entropy source components. Any information that can be shared regarding the design should also be included for any third-party entropy sources that are included in the product.
The documentation will describe the operation of the entropy source to include how entropy is produced, and how unprocessed (raw) data can be obtained from within the entropy source for testing purposes. The documentation should walk through the entropy source design indicating where the entropy comes from, where the entropy output is passed next, any post-processing of the raw outputs (hash, XOR, etc.), if/where it is stored, and finally, how it is output from the entropy source. Any conditions placed on the process (e.g., blocking) should also be described in the entropy source design. Diagrams and examples are encouraged.
This design must also include a description of the content of the security boundary of the entropy source and a description of how the security boundary ensures that an adversary outside the boundary cannot affect the entropy rate.
If implemented, the design description shall include a description of how third-party applications can add entropy to the RBG. A description of any RBG state saving between power-off and power-on shall be included.
D.2 Entropy Justification
There should be a technical argument for where the unpredictability in the source comes from and why there is confidence in the entropy source delivering sufficient entropy for the uses made of the RBG output (by this particular TOE). This argument will include a description of the expected min-entropy rate (i.e. the minimum entropy (in bits) per bit or byte of source data) and explain that sufficient entropy is going into the TOE randomizer seeding process. This discussion will be part of a justification for why the entropy source can be relied upon to produce bits with entropy.
The amount of information necessary to justify the expected min-entropy rate depends on the type of entropy source included in the product.
For developer provided entropy sources, in order to justify the min-entropy rate, it is expected that a large number of raw source bits will be collected, statistical tests will be performed, and the min-entropy rate determined from the statistical tests. While no particular statistical tests are required at this time, it is expected that some testing is necessary in order to determine the amount of min-entropy in each output.
For third party provided entropy sources, in which the TOE vendor has limited access to the design and raw entropy data of the source, the documentation will indicate an estimate of the amount of min-entropy obtained from this third-party source. It is acceptable for the vendor to “assume” an amount of min-entropy, however, this assumption must be clearly stated in the documentation provided. In particular, the min-entropy estimate must be specified and the assumption included in the ST.
Regardless of type of entropy source, the justification will also include how the DRBG is initialized with the entropy stated in the ST, for example by verifying that the min-entropy rate is multiplied by the amount of source data used to seed the DRBG or that the rate of entropy expected based on the amount of source data is explicitly stated and compared to the statistical rate. If the amount of source data used to seed the DRBG is not clear or the calculated rate is not explicitly related to the seed, the documentation will not be considered complete.
The entropy justification shall not include any data added from any third-party application or from any state saving between restarts.
D.3 Operating Conditions
The entropy rate may be affected by conditions outside the control of the entropy source itself. For example, voltage, frequency, temperature, and elapsed time after power-on are just a few of the factors that may affect the operation of the entropy source. As such, documentation will also include the range of operating conditions under which the entropy source is expected to generate random data. Similarly, documentation shall describe the conditions under which the entropy source is no longer guaranteed to provide sufficient entropy. Methods used to detect failure or degradation of the source shall be included.
D.4 Health Testing
More specifically, all entropy source health tests and their rationale will be documented. This will include a description of the health tests, the rate and conditions under which each health test is performed (e.g., at startup, continuously, or on-demand), the expected results for each health test, TOE behavior upon entropy source failure, and rationale indicating why each test is believed to be appropriate for detecting one or more failures in the entropy source.
Appendix E - Key Management Description
The documentation of the product’s encryption key management should be detailed enough that, after reading, the evaluator will thoroughly understand the product’s key management and how it meets the requirements to ensure the keys are adequately protected. This documentation should include an essay and diagrams. This documentation is not required to be part of the TSS - it can be submitted as a separate document and marked as developer proprietary.
Essay:
The essay will provide the following information for all keys in the key chain:
The purpose of the key
If the key is stored in non-volatile memory
How and when the key is protected
How and when the key is derived
The strength of the key
When or if the key would be no longer needed, along with a justification.
The essay will also describe the following topics:
A description of all authorization factors that are supported by the product and how each factor is handled, including any conditioning and combining performed.
If validation is supported, the process for validation shall be described, noting what value is used for validation and the process used to perform the validation. It shall describe how this process ensures no keys in the key chain are weakened or exposed by this process.
The authorization process that leads to the ultimate release of the BEV. This section shall detail the key chain used by the product. It shall describe which keys are used in the protection of the BEV and how they meet the derivation, key wrap, or a combination of the two requirements, including the direct chain from the initial authorization to the BEV. It shall also include any values that add into that key chain or interact with the key chain and the protections that ensure those values do not weaken or expose the overall strength of the key chain.
The diagram and essay will clearly illustrate the key hierarchy to ensure that at no point the chain could be broken without a cryptographic exhaust or all of the initial authorization values and the effective strength of the BEV is maintained throughout the Key Chain.
A description of the data encryption engine, its components, and details about its implementation (e.g. for hardware: integrated within the device’s main SOC or separate co-processor, for software: initialization of the product, drivers, libraries (if applicable), logical interfaces for encryption/decryption, and areas which are not encrypted (e.g. boot loaders, portions associated with the Master Boot Record (MBRs), partition tables, etc.)). The description should also include the data flow from the device’s host interface to the device’s persistent media storing the data, information on those conditions in which the data bypasses the data encryption engine (e.g. read-write operations to an unencrypted Master Boot Record area). The description should be detailed enough to verify all platforms to ensure that when the user enables encryption, the product encrypts all hard storage devices. It should also describe the platform’s boot initialization, the encryption initialization process, and at what moment the product enables the encryption.
The process for destroying keys when they are no longer needed by describing the storage location of all keys and the protection of all keys stored in non-volatile memory.
Diagram:
The diagram will include all keys from the initial authorization factors to the BEV and any keys or values that contribute into the chain. It must list the cryptographic strength of each key and indicate how each key along the chain is protected with either Key Derivation or Key Wrapping (from the allowed options). The diagram should indicate the input used to derive or unwrap each key in the chain.
A functional (block) diagram showing the main components (such as memories and processors) and the data path between, for hardware, the device’s host interface and the device’s persistent media storing the data, or for software, the initial steps needed for the activities the TOE performs to ensure it encrypts the storage device entirely when a user or administrator first provisions the product. The hardware encryption diagram shall show the location of the data encryption engine within the data path.
The hardware encryption diagram shall show the location of the data encryption engine within the data path. The evaluator shall validate that the hardware encryption diagram contains enough detail showing the main components within the data path and that it clearly identifies the data encryption engine.
