PP-Module for Authentication Servers

Version: 1.0
2023-01-25
National Information Assurance Partnership

Revision History

Version	Date	Comment
1.0	2023-01-25	Initial Release

1Introduction 1.1Overview 1.2Terms 1.2.1Common Criteria Terms 1.2.2Technical Terms 1.3Compliant Targets of Evaluation 1.4TOE Boundary 1.5Use Cases 2Conformance Claims 3Security Problem Description 3.1Threats 3.2Assumptions 3.3Organizational Security Policies 4Security Objectives 4.1Security Objectives for the TOE 4.2Security Objectives for the Operational Environment 4.3Security Objectives Rationale 5Security Requirements 5.1NDcPP Security Functional Requirements Direction 5.1.1 Modified SFRs 5.1.1.1Identification and Authentication (FIA)5.2TOE Security Functional Requirements 5.2.1Security Audit (FAU)5.2.2Communications (FCO)5.2.3Cryptographic Support (FCS)5.2.4Identification and Authentication (FIA)5.2.5Security Management (FMT)5.2.6TOE Access (FTA)5.2.7Trusted Path/Channels (FTP)5.3TOE Security Functional Requirements Rationale 5.4TOE Security Assurance Requirements 6Consistency Rationale 6.1Collaborative Protection Profile for Network Devices 6.1.1 Consistency of TOE Type 6.1.2 Consistency of Security Problem Definition 6.1.3 Consistency of Objectives 6.1.4 Consistency of Requirements Appendix A - Optional SFRs A.1Strictly Optional Requirements A.2Objective Requirements A.3Implementation-based Requirements Appendix B - Selection-based Requirements B.1Cryptographic Support (FCS)B.2Identification and Authentication (FIA)Appendix C - Extended Component Definitions C.1Extended Components Table C.2Extended Component Definitions C.2.1Cryptographic Support (FCS)C.2.1.1FCS_EAPTLS_EXT EAP-TLS Protocol C.2.1.2FCS_RADIUS_EXT Authentication Protocol C.2.1.3FCS_STG_EXT Cryptographic Key Storage C.2.1.4FCS_RADSEC_EXT RadSec C.2.2Identification and Authentication (FIA)C.2.2.1FIA_HOTP_EXT HMAC-Based One-Time Password Pre-Shared Keys C.2.2.2FIA_PSK_EXT Pre-Shared Keys C.2.2.3FIA_TOTP_EXT Time-Based One-Time Password Pre-Shared Keys Appendix D - Implicitly Satisfied Requirements Appendix E - Allocation of Requirements in Distributed TOEs Appendix F - Entropy Documentation and Assessment Appendix G - Acronyms Appendix H - Bibliography

1 Introduction

1.1 Overview

An authentication server provides assertions to a relying party that a particular request for access is from an authentic digital identity associated with various identity attributes, such as a registered account within an information system, or a certified identity as validated by a trusted certification authority or both. The digital identities can represent people, devices, or processes. Authentication servers validate various authenticators controlled by the entities represented by the presented digital identity. When the entity is a person, authenticators can provide indications of what the entity knows (e.g., a password, pin, or passphrase), what the entity has (e.g., a registered device in the control of the user), or what the entity is (a biometric). NIST SP 800-63-3 Part B provides recommendations about how these authenticators can be leveraged individually or in combinations to provide assurance that the entity is authentic and describes requirements for validation of the authenticators to various assurance levels.

A relying party may delegate verification of authenticators to an authentication server; such delegation creates a relationship between the relying party and the authentication server that is referred to as an identity federation. Assertions to a federated relying party can be via bearer assertions or via direct communication with the relying party. The latter mechanism is modeled after that used by Authentication, Access, and Accounting (AAA) servers, which used the RADIUS protocol. RADIUS has been largely replaced by DIAMETER, a protocol that addresses many of the security issues with RADIUS. These provide direct, back-end assertions protected by an authenticated and encrypted channel to a Network Access Server (NAS) that further governs accesses to resources on a network.

This PP-module describes the security functionality of authentication servers supporting RADIUS or DIAMETER and other messaging protocols intended for direct communications with relying parties via authenticated, real-time protected channels.

The scope of this PP-Module is to describe the security functionality of an authentication server in terms of [CC] and to define functional and assurance requirements for such products. This PP-Module is intended for use with the following Base-PP:

collaborative Protection Profile for Network Devices, Version 2.2e (NDcPP)

This Base-PP is valid because an authentication server can be deployed as a dedicated network appliance. The use case of deploying the authentication server as an application on a general-purpose computer is outside the scope of this PP-Module. Authentication server products allow enterprises to provide a centralized and standardized method of evaluating user authentication requests made throughout the enterprise. This enables a centralized definition for user identity and credential data and allows for uniform application of authentication policies that define what credentials and user attributes are necessary to gain access to various systems and applications in the enterprise environment.

Note that the NDcPP defines an optional architecture for a “distributed TOE” that allows for security functionality to be spread across multiple distinct components. This PP-Module does not require or prohibit the TOE from being a distributed system when the TOE conforms to the NDcPP; the TOE may be standalone or distributed in this case.

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.
Distributed TOE	A TOE composed of multiple components operating as a logical whole.
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.
Protection Profile Configuration (PP-Configuration)	A comprehensive set of security requirements for a product type that consists of at least one Base-PP and at least one PP-Module.
Protection Profile Module (PP-Module)	An implementation-independent statement of security needs for a TOE type complementary to one or more Base-PPs.
Security Assurance Requirement (SAR)	A requirement to assure the security of the TOE.
Security Functional Requirement (SFR)	A requirement for security enforcement by the TOE.
Security Target (ST)	A set of implementation-dependent security requirements for a specific product.
Target of Evaluation (TOE)	The product under evaluation.
TOE Security Functionality (TSF)	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

Assertion	A statement from the TOE to an RP that contains information about a subscriber. Assertions may also contain verified attributes. For the purposes of this PP-Module, assertions containing authentication status and identity attributes are made by EAP response messages in accordance with EAP-TLS or EAP-TTLS.
Authentication Policy	A policy that specifies which authenticator types are required for a particular entity. The policy may be implicit for all entities, or configurable.
Authenticator	Something the claimant possesses and controls (typically a cryptographic module or password) that is used to authenticate the claimant’s identity.
Authenticator Output	The output value generated by an authenticator. The ability to generate valid authenticator outputs on demand proves that the claimant possesses and controls the authenticator. Protocol messages sent to the verifier are dependent upon the authenticator output, but they may or may not explicitly contain it.
Claimant	A subject whose identity is to be verified using one or more authentication protocols.
Credential	An object or data structure that authoritatively binds an identity via an identifier or identifiers and (optionally) additional attributes, to at least one authenticator possessed and controlled by a subscriber.
Federation Protocol	A protocol to establish a trusted relationship with a relying party, and for the purposes of this PP module, to communicate authentication status for entities requesting access to resources managed by the relying party. In this PP-module, Federation Protocols include RADIUS, DIAMETER, and other standard protocols used in direct communication between the relying party and the TOE. Federation protocols that only support bearer assertions are out of scope for this PP-Module.
Relying Party (RP)	An entity that relies upon the subscriber’s authenticators and credentials or a verifier’s assertion of a claimant’s identity, typically to process a transaction or grant access to information or a system.

1.3 Compliant Targets of Evaluation

This PP-Module specifically addresses a dedicated network device that performs entity (device or user) authentication via direct, back-end connections with a relying party. The entity to be authenticated is referred to as the claimant, though different terms have been used for specific protocols (e.g., peer for RADIUS or DIAMETER). The relying party can manage a single resource or provide access control for resources within a network. For example, a Wireless Local Area Network (WLAN) Access System may use the services of a dedicated authentication server during tunnel establishment. In this use case, an authentication server must support IEEE 802.1X Port-Based Network Access Control and must fulfill the IEEE 802.11 authentication server role using Extensible Authentication Protocol (EAP) messaging.

Similarly, the authentication server may be used during Virtual Private Network (VPN) tunnel establishment. The relying party in this case is a VPN Gateway acting as a Network Access Server using pass-through between the VPN client and authentication server (the TOE), also using EAP messaging.

In general, any relying party using a direct authentication federation protocol that supports EAP-TLS or EAP-TTLS messaging is addressed by this PP-Module.

The combination of the NDcPP and this PP-Module is a network device that provides authentication server functionality in addition to all of the security functionality expected of a network device as mandated by the NDcPP.

This PP-Module describes the functional requirements and threats specific to authentication servers. A TOE that conforms to this PP-Module must also conform to the Base-PP.

1.4 TOE Boundary

This document specifies SFRs for an authentication server. An authentication server is designed to authenticate a claimant that attempts to access a relying party – an access gateway to a protected network, or individual resources and services – and provide assertions to one or more relying parties about the authentication state of the claimant. A claimant forwards one or more authenticator outputs to the authentication server; the authentication server verifies the authenticator outputs and may also provide additional identity attributes to allow the relying party to determine whether the claimant meets its authentication policy.

The authentication server defined by this PP-Module is one or more dedicated network appliances; the TOE is not intended to run as an application on a general-purpose computer. The authentication server can be co-located with an access management or privilege management system, or it may be separate from such services. Regardless of the deployment, access control functions and management of non-identity attributes are outside the scope of this PP-Module.

An authentication server may be part of a larger system that also provides authorization information, either as part of an AAA server, an authorization server, or a domain controller. This PP-Module specifies the functional requirements for authentication services only; as in the case where the TOE may be co-located with the relying party, the TOE’s logical boundary only includes the authentication server functionality. However, the TOE boundary includes the ability to generate audit events that are specific to the authentication functionality but may be used to support other functions (e.g., AAA servers).

Figure 1: NAS with an Authentication Server

Figure 2: Generic Authentication Server User Case

1.5 Use Cases

This PP-Module defines the potential use cases below for the authentication server TOE. Use Case 1 defines the physical embodiment of the TOE, while Use Cases 2-4 define its role in a network infrastructure.

[USE CASE 1] Dedicated Appliance: The authentication server is integrated on a standalone network appliance. In this use case, conformance to the NDcPP and this PP-Module is sufficient to ensure security. This PP-Module does not cover the use case where the authentication server is an application that is installed on a general-purpose computer.
[USE CASE 2] Standalone Server: The system on which the authentication server is deployed is solely responsible for acting as an authenticator. In this deployment, the authentication server’s only network infrastructure role is to communicate with the relying party for receiving challenges and issuing responses.
[USE CASE 3] Relying Party Co-Location: The system on which the authentication server is deployed acts as both the relying party or its proxy and the authentication server. In this deployment, the authentication server’s interactions with the relying party are internal-only. Regardless of whether the relying party is a standalone component or the authentication server executable code also provides relying party functionality, the TOE’s logical boundary still only includes the authentication server component. Additionally, if the authentication server is a software application that can be deployed independent of the relying party, the required external trusted communications must still be supported; an authentication server cannot use the fact that it can be deployed on the same physical server as the relying party as a way to exempt itself from implementation of IPsec, RadSec, or mutually authenticated (D)TLS with an external relying party.
[USE CASE 4] Integrated as an Authorization Server Component: The system on which the authentication server is deployed also acts as an authorization server (e.g., as part of an AAA server) that provides authorization services in addition to the authentication server. Assertions made via the direct connection can also include authorization information, and an unauthorized, but authenticated user may result in a negative response to the relying party. Regardless of whether these are all standalone components or the authentication server executable code also provides authorization functionality, the TOE’s logical boundary still only includes the authentication server component. As in the case where the authentication server is co-located with the relying party, this deployment does not exempt the TOE from being able to implement all the functionality that this PP-Module requires.

2 Conformance Claims

Conformance Statement: This PP-Module inherits exact conformance as required from the specified Base-PP and as defined in the CC and CEM addenda for Exact Conformance, Selection-Based SFRs, and Optional SFRs (dated May 2017).

No PPs or PP-Modules may be specified in a PP-Configuration with this PP-Module other than the Base-PP specified in Section 1.1 Overview .
CC Conformance Claims: This PP-Module is conformant to Parts 2 (extended) and 3 (conformant) of Common Criteria Version 3.1, Release 5 [CC].
Package Claims: This PP-Module does not claim conformance to any packages.

3 Security Problem Description

The security problem is described in terms of the threats that the TOE is expected to address, assumptions about its Operational Environment, and any organizational security policies that the TOE is expected to enforce.

3.1 Threats

The following threats that are defined in this PP-Module extend the threats that are defined by the Base-PP.

T.FALSE_ENDPOINTS: A malicious actor may falsely impersonate the TOE or a federated relying party in order to cause the TOE to operate in an insecure manner or to extract security-relevant, or sensitive user data from the TOE or its Operational Environment.
T.INVALID_USERS: A malicious user may supply incorrect or insufficient credential data or an otherwise invalid authentication request that is approved or ignored by the TSF such that protected resources are subject to unauthenticated access.

3.2 Assumptions

These assumptions are made on the Operational Environment (OE) in order to be able to ensure that the security functionality specified in the PP-Module can be provided by the TOE. If the TOE is placed in an OE that does not meet these assumptions, the TOE may no longer be able to provide all of its security functionality. All assumptions for the OE of the Base-PP also apply to this PP-Module.

A.RP_FEDERATION: It is assumed that the TOE is federated with one or more relying parties that transmit authentication requests to it.

3.3 Organizational Security Policies

An organization deploying the TOE is expected to satisfy the organizational security policy listed below in addition to all organizational security policies defined by the claimed Base-PP.

P.AUTH_POLICY: The organization defines, for each protected resource, an authentication policy that specifies the authenticators that must be provided to access a given resource.

4 Security Objectives

4.1 Security Objectives for the TOE

O.AUTHORIZED_USE: The TOE shall provide mechanisms that prevent and detect its unauthorized use.
O.SECURITY_ASSOCIATION: The TOE shall provide the information to the relying party to enable it to verify that the claimant has possession of an authentication key.
O.TRUSTED_RP: The TOE shall provide mechanisms to authenticate itself to a federated RP and authenticate a federated RP before providing an identity assertion.
O.USER_AUTH: The TOE shall provide a mechanism to assess authentication requests and respond with an authentication assertion based on data that is supplied in the request.

4.2 Security Objectives for the Operational Environment

All objectives for the OE of the Base-PP also apply to this PP-Module.

OE.RP_FEDERATION: The TOE will be deployed in such a manner that it is federated with one or more relying parties that transmit authentication requests to it.
OE.REQUIRE_AUTH: The operational environment will protect assets in a manner that requires authentication commensurate with the sensitivity of the assets.

4.3 Security Objectives Rationale

This section describes how the assumptions, threats, and organizational security policies map to the security objectives.

Table 1: Security Objectives Rationale
Threat, Assumption, or OSP	Security Objectives	Rationale
T.FALSE_ENDPOINTS	O.TRUSTED_RP	The TOE’s enforcement of mutual authentication allows it and the relying party to identify and reject attempts for each component to be impersonated.
T.INVALID_USERS	O.SECURITY_ASSOCIATION	The TOE’s ability to maintain a security association ensures that a mechanism exists for the TSF to assert to an external entity that a given user is valid.
T.INVALID_USERS	O.USER_AUTH	The TOE’s proper implementation of the claimant authentication ensures that it will accurately process authentication attempts to allow only valid authentication attempts. The TOE’s ability to use trusted communications as part of the federation protocol implementation ensures that modification or disclosure of authentication data cannot be used as a method to gain access to credentials or modify an authentication result.
T.UNAUTHORIZED_ADMINISTRATOR_ACCESS (from NDcPP)	O.AUTHORIZED_USE	The TOE further mitigates this threat originally defined in the Base-PP by defining additional management functions that require authorization and additional interfaces that can be used securely to execute management activities.
T.UNDETECTED_ACTIVITY (from NDcPP)	O.AUTHORIZED_USE	The TOE further mitigates this threat originally defined in the Base-PP by implementing measures to generate audit records for security-relevant events that are specific to the functionality defined by this PP-Module.
A.RP_FEDERATION	OE.RP_FEDERATION	The OE objective OE.RP_FEDERATION is realized through A.RP_FEDERATION .
P.AUTH_POLICY	OE.REQUIRE_AUTH	Definition of an authentication policy, which can be enforced through deployment of a conformant TOE, can be used to ensure that organizational assets are protected by enforcing appropriate requirements for authentication.

5 Security Requirements

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 (including replacing an assignment with a more restrictive selection) 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 NDcPP Security Functional Requirements Direction

In a PP-Configuration that includes the NDcPP, the TOE is expected to rely on some of the security functions implemented by the Authentication Server as a whole and evaluated against the NDcPP. The following sections describe any modifications that the ST author must make to the SFRs defined in the NDcPP in addition to what is mandated by Section 5.2 TOE Security Functional Requirements .

5.1.1 Modified SFRs

The SFRs listed in this section are defined in the NDcPP and relevant to the secure operation of the TOE.

5.1.1.1 Identification and Authentication (FIA)

FIA_X509_EXT.1/Rev X.509 Certificate Validation

FIA_X509_EXT.1.1/Rev

This SFR is selection-based in the NDcPP. When the TOE conforms to this PP-Module it is mandatory because of the PP-Module's certificate-based authentication of the channel between the TOE and a federated relying party.

FIA_X509_EXT.2 X.509 Certificate Authentication

FIA_X509_EXT.2.1

This SFR is selection-based in the NDcPP. When the TOE conforms to this PP-Module it is mandatory because of the PP-Module's requirement for certificate-based authentication of the channel between the TOE and a federated relying party using IPsec with certificate-based authentication, mutually authenticated TLS or DTLS, or RADsec, which in turn uses IPsec or mutually authenticated TLS or DTLS.

FIA_X509_EXT.3 X.509 Certificate Requests

FIA_X509_EXT.3.1

This SFR is selection-based in the NDcPP. When the TOE conforms to this PP-Module it is mandatory because of the PP-Module's requirement for implementation of mutually-authenticated TLS or DTLS.

5.2 TOE Security Functional Requirements

The following section describes the SFRs that must be satisfied by any TOE that claims conformance to this PP-Module. These SFRs must be claimed regardless of which PP-Configuration is used to define the TOE.

5.2.1 Security Audit (FAU)

FAU_GEN.1/AuthSvr Audit Data Generation (Authentication Server)

FAU_GEN.1.1/AuthSvr

The TSF shall be able to generate an audit record of the following auditable events:

Start-up and shutdown of the audit functions;
All auditable events for the [not specified] level of audit; and
[Auditable events listed in the Auditable Events table (Table 2)

Requirement	Auditable Events	Additional Audit Record Contents
FCO_NRO.1	Claimant request for which the TOE does not have credential verification data	Identity of the claimant
FCO_NRR.1	None
FCS_CKM.3	[selection: attempt to export plaintext key or CSP via defined interface, none] Note: if no defined interfaces have access to persistent keys or CSP, select 'none'	If attempt is detected, record process identifier, authorized user's identifier (if any)
FCS_EAPTLS_EXT.1	Protocol failures	If failure occurs, record a descriptive reason for the failure
FCS_EAPTLS_EXT.1	Successful and failed authentication of claimant	Identifier of claimant
FCS_RADIUS_EXT.1	Protocol failures	If failure occurs, record a descriptive reason for the failure
FCS_RADIUS_EXT.1	Success/failure of authentication	None
FCS_RADSEC_EXT.1 (selection-based)	None
FCS_STG_EXT.1	None
FIA_AFL.1/AuthSvr	The reaching of the threshold for the unsuccessful authentication attempts	The claimed identity of the entity attempting to authenticate or the IP where the attempts originated
FIA_AFL.1/AuthSvr	Disabling an account due to the threshold being reached
FIA_HOTP_EXT.1 (selection-based)	Generation of a HOTP seed key	Entity identifier
FIA_HOTP_EXT.1 (selection-based)	Entity HOTP value comparison	Result of comparison - success or failure
FIA_PSK_EXT.1/AuthSvr (selection-based)	None
FIA_PSK_EXT.2 (selection-based)	None
FIA_PSK_EXT.3 (selection-based)	None
FIA_TOTP_EXT.1 (selection-based)	Generation of a TOTP seed key	Entity identifier
FIA_TOTP_EXT.1 (selection-based)	Entity TOTP value comparison	Result of comparison - success or failure
FIA_X509_EXT.1/AuthSvr	Certificate validation failure	Reason for failure
FIA_UAU.6	All use of the authentication mechanism	Origin of the attempt (e.g., IP address)
FMT_SMF.1/AuthSvr	All management actions	Identifier of initiator
FTA_TSE.1	Denial of session establishment due to the session establishment mechanism	Reason for denial, origin of establishment attempt
FTP_ITC.1/NAS	Initiation of the trusted channel	Identification of the initiator
	Termination of the trusted channel	Identification of the initiator
	Failure of the trusted channel functions	Target of failed trusted channels establishment attempt

Table 2: Auditable Events

Application Note:

The auditable events defined in Table 2 are for the SFRs that are explicitly defined in this PP-Module and are intended to extend FAU_GEN.1 in the Base-PP.

The events in the Auditable Events table should be combined with those of the NDcPP in the context of a conforming Security Target.

The Auditable Events table (Table 2) includes selection-based SFRs. The auditing of selection-based SFRs is only required if that SFR is included in the ST.

Per FAU_STG_EXT.1 in the Base-PP, the TOE must support transfer of the audit data to an external IT entity using a trusted channel.

FAU_GEN.1.2/AuthSvr

The TSF shall record within each audit record at least the following information:

Date and time of the event, type of event, subject identity, and the outcome (success or failure) of the event; and
For each audit event type, based on the auditable event definitions of the functional components included in the PP-Module/ST, [information specified in column three of the Auditable Events table (Table 2)].

5.2.2 Communications (FCO)

FCO_NRO.1 Selective Proof of Origin

FCO_NRO.1.1

The TSF shall be able to generate evidence of origin for transmitted [identity authentication assertions, [selection: authentication requests, IKE authentication phase security associations, [assignment: claimant identity attributes], no other data ]] at the request of the [relying party, [selection: external authentication servers in support of pass-through, no other entities ]].

Application Note: The intent of this requirement is for the TOE to provide the source of origin (non-repudiation) for assertions and sensitive data associated to claimants it provides to relying parties. The ST author will claim ‘authentication requests’ and ‘external authentication servers…’ if the TSF supports pass-through communication with external authentication servers. The ST author claims additional information provided to a relying party via an authenticated channel as appropriate.

FCO_NRO.1.2

The TSF shall be able to relate the [authenticator] of the originator of the information, and the [authentication request] of the information to which the evidence applies.

Application Note: The intent of this requirement is for the TOE to be able to associate authentication assertions it makes to requests made to it by a relying party. For pass-through functionality, the TOE relates requests and response messages it forwards between external entities via identity information asserted in the EAP headers.

FCO_NRO.1.3

The TSF shall provide a capability to verify the evidence of origin of information to [recipient] given [an authenticated channel is established with a trusted relying party]].

FCO_NRR.1 Selective Proof of Receipt

FCO_NRR.1.1

The TSF shall be able to generate evidence of receipt for received [authentication requests, [selection: authentication responses and queries, none ]] at the request of the [originator].

Application Note: The intent of this requirement is for the TOE to be able to return a valid response to the relying party upon receipt of an Access-Request. If the TSF supports pass-through functionality, the ST author claims ‘authentication responses and queries’ in the selection for authentication in communications with external authentication servers.

FCO_NRR.1.2

The TSF shall be able to relate the [claimant identifier and claimant authenticators] of the recipient of the information, and the [identity assertion, information requests, and error responses] of the information to which the evidence applies.

Application Note: The intent of this requirement is for the ST author to list the information supplied by the TOE in response to an authentication request that confirms receipt of the request, and identifies:

the authentication request that is being responded to;
the mutually authenticated channel between the trusted relying party and the TOE.

FCO_NRR.1.3

The TSF shall provide a capability to verify the evidence of receipt of information to [originator] given [establishment of a mutually authenticated channel with a trusted relying party].

5.2.3 Cryptographic Support (FCS)

FCS_CKM.3 Cryptographic Key Access

FCS_CKM.3.1

The TSF shall perform [access control for persistent private and secret keys and critical security parameters required by this PP-Module] in accordance with a specified cryptographic key access method [ensuring only authorized security functionality can access plaintext keys or critical security parameters] that meets the following: [keys and critical security parameters are not exportable in plaintext and keys and critical security parameters are not viewable in plaintext].

Application Note: Exposure of keys used for assertion signatures, including private keys associated to certificates used to establish a protected channel to relying parties and claimants, one-time-password seed keys, and plaintext passwords can undermine or bypass the protections required for TOE functionality. The ST author describes the specific methods used to prevent unauthorized or unnecessary access to these keys and critical security parameters. This requirement is not intended to cover unanticipated exploits; it is only required that plaintext keys and critical security parameters not be exportable or viewable by defined interfaces. OTP seed key values are shared using out-of-band methods with the associated entities. This requirement implies that the method to export these values uses encrypted key transport methods.

FCS_EAPTLS_EXT.1 EAP-TLS Protocol

FCS_EAPTLS_EXT.1.1

The TSF shall implement [selection: EAP-TLS as specified in RFC 5216, EAP-TTLS as specified in RFC 5881 ] as updated by RFC 8996 with [selection: TLS, DTLS ] implemented using mutual authentication in accordance with [selection: FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2, FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2 ].

FCS_EAPTLS_EXT.1.2

The TSF shall generate random values used in the [selection: EAP-TLS, EAP-TTLS ] exchange using the RBG specified in FCS_RBG_EXT.1.

FCS_EAPTLS_EXT.1.3

The TSF shall support claimant authentication using certificates and [selection: static PSK, HOTP, TOTP, other authentication-verification methods via pass-through, no other methods ].

FCS_EAPTLS_EXT.1.4

The TSF shall not forward an EAP-Success response to the relying party if the client certificate is not valid according to FIA_X509_EXT.1/AuthSvr, if the [selection: TLS, DTLS ] session is not established, or if any of [selection: PSK, HOTP value, TOTP value, no other authenticator ] required by the authentication policy are not provided or if any of the required authenticators presented in the authentication request is not valid.

Application Note: The ST author should indicate support for EAP-TLS or EAP-TTLS in FCS_EAPTLS_EXT.1.1 . In the third selection, ‘FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2’ or 'FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2’ is selected according to the TLS or DTLS support indicated in the second selection, with the expectation that the corresponding SFRs from the Base-PP are claimed.

The selection in FCS_EAPTLS_EXT.1.2 matches the first selection in FCS_EAPTLS_EXT.1.1 .

The selections made in FCS_EAPTLS_EXT.1.3 may trigger the inclusion of selection-based SFRs, as follows:

Any of "static PSK," "HOTP," or "TOTP" requires inclusion of FIA_PSK_EXT.1/AuthSvr .
"HOTP" requires inclusion of FIA_HOTP_EXT.1 .
"TOTP" requires inclusion of FIA_TOTP_EXT.1

The ST author claims any additional supported authentication-verification methods in FCS_EAPTLS_EXT.1.3 . Each supported method is claimed independently, even if combinations of the methods are required for individual claimant authentication. For any authentication methods that are only supported by pass-through functionality, the ST author should claim 'other authentication-verification methods via pass-through' without claiming the corresponding method in the same selection. Pass-through functionality can typically support any authentication method, including ones not specified in the SFR. However, it is preferred that the TSF not use pass-through functionality for EAP methods that do not align to standardized methods utilizing certificate-based authentication of the claimant.

FCS_RADIUS_EXT.1 Authentication Protocol

FCS_RADIUS_EXT.1.1

The TSF shall implement the [selection: RADIUS protocol as specified in RFC 2865, DIAMETER protocol as specified in RFC 6733, [assignment: other direct identity federation protocol] ] for communication of identity and authentication information with a relying party.

FCS_RADIUS_EXT.1.2

The TSF shall implement encapsulated EAP in accordance with FCS_EAPTLS_EXT.1 .

FCS_RADIUS_EXT.1.3

The TSF shall provide [selection: a key indicator, an encrypted parameter, an encrypted value ] for a key held by the successfully authenticated claimant derived from the supported EAP mode and provided to the relying party in accordance with the protocol indicated in FCS_RADIUS_EXT.1.1 .

Application Note: The ST author describes how the TSF communicates with a relying party at the application layer to receive authentication requests and provide identity assertions. RADIUS and DIAMETER protocols are used with AAA servers when the relying party is a NAS. However, other direct access identity federation protocols that support FCS_EAPTLS_EXT.1 and identify a key held by the authenticated claimant that can be confirmed by the relying party are acceptable. If other protocols are claimed, the ST author includes the RFCs and indicates the messages used for authentication requests and assertions.

The ST author indicates which keys held by the authenticated claimant are available to the relying party for key-holder verification. For RADIUS and DIAMETER, the EAP-TLS/EAP-TTLS master key established during the TLS handshake with the claimant is shared with the relying party, encrypted under the protected channel between the TSF and the relying party. Both the relying party and claimant derive the AUTH MSK/security association for an IPsec session from this master key. More generally, a key indicator can be a reference identifier for a shared secret key, or a public key, certificate, or other identifier associated with a private asymmetric key controlled by the authenticated claimant.

FCS_STG_EXT.1 Cryptographic Key Storage

FCS_STG_EXT.1.1

Persistent private and secret keys shall be stored within the TSF [selection:

encrypted within a hardware protected key
in a hardware cryptographic module
within an isolated execution environment protected by a hardware key

5.2.4 Identification and Authentication (FIA)

FIA_AFL.1/AuthSvr Authentication Failure Handling (Claimant)

FIA_AFL.1.1/AuthSvr

The TSF shall detect when [an administrator configurable positive integer of successive] unsuccessful authentication attempts occur related to [claimants attempting to authenticate].

FIA_AFL.1.2/AuthSvr

When the defined number of unsuccessful authentication attempts has been [met], the TSF shall [selection, choose one of: prevent the offending remote entity from successfully authenticating until [assignment: action] is taken by a local Administrator, prevent the offending claimant from successfully authenticating until an administrator-defined time period has elapsed ].

Application Note: This requirement applies to claimant authentication attempts in support of an authentication service provided for a federated relying party. This requirement does not apply to login to the TOE by privileged users for administrative accesses; these cases are addressed by the Base-PP iteration of this SFR. Responses to authentication queries to aid the claimant in providing acceptable authenticators is not considered a preventative action and are allowed prior to reaching the lockout threshold. The “action” taken by a local administrator is implementation specific and is defined in the operational guidance (for example, lockout reset or password reset). The ST author chooses one of the selections for handling of authentication failures depending on how the TOE has implemented this handler.

FIA_UAU.6 Re-Authenticating

FIA_UAU.6.1

The TSF shall re-authenticate the administrative user under the conditions [when the user changes their password, [selection: following TSF-initiated session locking, [assignment: other conditions], no other conditions ]].

FIA_X509_EXT.1/AuthSvr X.509 Certificate Validation (Claimant)

FIA_X509_EXT.1.1/AuthSvr

The TSF shall validate certificates in accordance with the following rules:

RFC 5280 version 3 certificate validation and certification path validation supporting [selection: a minimum path length of [assignment: value greater than or equal to three], no prior constraints on path length ]
The certification path must terminate with a CA certificate trusted by the TSF specifically for claimant authentication.
The TSF shall validate a certification path by ensuring that all CA certificates in the certification path contain the basicConstraints extension with the CA flag set to TRUE.
The TSF shall validate the revocation status of each certificate in the certificate path [selection:
containing an OCSP provider in the AIA extension using the Online Certificate Status Protocol (OCSP) as specified in RFC 6960
containing a certificate revocation list (CRL) distribution point in the CRLDP extension or AIA extension using [selection: a CRL as specified in RFC 5280 Section 6.3, a CRL as specified in RFC 5759 Section 5 ]
].
The TSF shall validate the extendedKeyUsage field is present and contains key usage values according to the following rules: [selection:
Certificates do not assert anyExtendedKeyUsage (OID 2.5.29.37.0)
Client certificates associated with authenticated entities presented for [selection: TLS, DTLS ] shall have the Client Authentication purpose (id-kp 2 with OID 1.3.6.1.5.5.7.3.2) in the extendedKeyUsage field.
[selection:
Server certificates presented for [selection: TLS, DTLS ] shall have the Server Authentication purpose (id-kp 1 with OID 1.3.6.1.5.5.7.3.1) in the extendedKeyUsage field.
Certificates presented for IPsec shall have the ipsec-IKE purpose (id-kp 17 with OID 1.3.6.1.5.5.7.3.17)
OCSP certificates presented for OCSP responses shall have the OCSP Signing purpose (id-kp 9 with OID 1.3.6.1.5.5.7.3.9) in the extendedKeyUsage field.
]
].

The TSF shall validate that each CA certificate in the certification path indicating a path length constraint in the basicConstraints extension does not have more than the specified number of subordinate CA certificates in the certification path from the end-entity certificate to the CA certificate indicating the constraint, not counting the CA certificate itself or any self-issued certificates in the certification path.

The TSF shall process name constraints of type Directory Name and [selection: rfc822Name, dnsName, UPN Name (Other Name = id-ms-san-sc-logon-upn), [assignment: other name type], no other name type ] by verifying that each name of a supported name type present in the end-entity certificate subject field or subjectAlternateName extension, is allowed in each CA certificate in the certification path, is not disallowed by any of the CA certificates in the certification path, and that each name type included in the end-entity certificate and constrained by a CA certificate in the certification path is processed.

The TSF shall process the following certificate extensions: [selection:
Certificate Policy extension in accordance with RFC 5280 and [selection:
Policy mapping extension in accordance with RFC 5280
Policy constraints extension in accordance with RFC 5280
Inhibit anyPolicy extension in accordance with RFC 5280
No other policy related extension
] in support of claimant authentication and [assignment: other intended purposes and limitations of policy related extension processing]
[assignment: other standard extensions]
no other extensions
].

Application Note:

This SFR is iterated from the Base-PP to define X.509 validation requirements that are specific to claimaint authentication.

The ST author claims supported certificate validity checking options for each rule. For name constraints, all supported name types used to match names presented in a certificate to registered users and the associated standard matching method are described.

The ST author claims supported certificate policies. ‘Policy Constraints…’ is claimed if the TOE’s authentication policy depends on the certificate policies for claimant certificates. Other policy related extensions within the selection are claimed if supported. The extension inhibitPolicyMapping is not claimed if the TSF does not support certificate chains of length four or more. The policy related extensions, if supported, are primarily used in this PP-Module for claimant authentication, but are allowed for other certificate authentications. The ST author specifies the intended use and any limits of support for these extensions or specifies ‘no other policy related extension’ in the assignment of this selection.

The ST author specifies any additional supported X.509 extensions, and the associated extension processing rules used to determine claimant identity attributes or conditions that can be used in the TOE’s authentication policy.

FIA_X509_EXT.1.2/AuthSvr

The TSF shall only treat a certificate as a CA certificate if the basicConstraints extension is present and the CA flag is set to TRUE.

5.2.5 Security Management (FMT)

FMT_SMF.1/AuthSvr Specification of Management Functions (Authentication Server)

FMT_SMF.1.1/AuthSvr

The TSF shall be capable of performing the following management functions: [

Ability to configure claimant verification data

Ability to manage trust store data

Ability to configure administrator authentication credential

Ability to configure trusted channel to relying party

[selection:
Ability to configure IPsec functionality
Ability to configure DTLS functionality
Ability to configure TLS functionality
Ability to manage claimant authentication policy
Ability to manage supported authentication-verification methods
Ability to manage supported authentication-verification methods supported via pass-through functionality
Ability to configure RADIUS shared secret
Ability to define authorized relying parties
Ability to configure cryptographic key storage
Ability to configure lockout policy for failed claimant authentication
Ability to unlock a claimant account
Ability to configure certificate validation checking mechanisms
Ability to define conditions in which claimant authentication attempts are rejected
Ability to associate pre-shared keys with claimants or external entities
Ability to configure restrictions on the composition of pre-shared keys
Ability to configure restrictions on the validation of pre-shared keys
Ability to generate pre-shared keys
Ability to accept pre-shared keys
Ability to manage HOTP verification function
Ability to manage TOTP verification function
No other functions
]

].

Application Note: This SFR defines additional management functions for the TOE beyond what is defined in the Base-PP as FMT_SMF.1.

5.2.6 TOE Access (FTA)

FTA_TSE.1 TOE Session Establishment

FTA_TSE.1.1

The TSF shall be able to deny claimant session establishment based on [invalid certificate, [selection: [assignment: other identity attributes], no other attributes ]].

Application Note: The intent of this SFR is to describe any circumstances that would cause a claimant’s authentication request to be rejected. All compliant TOEs will reject authentication requests based on invalid credentials. A compliant TOE may also impose additional limitations such as suspended accounts or time of day restrictions, depending on the capabilities of the TSF’s authentication mechanism.

5.2.7 Trusted Path/Channels (FTP)

FTP_ITC.1/NAS Inter-TSF Trusted Channel (Relying Party Communications)

FTP_ITC.1.1/NAS

The TSF shall provide [selection: an IPsec, a RadSec, a mutually authenticated TLS, a mutually authenticated DTLS ] communication channel between itself and a relying party that is logically distinct from other communication channels and provides assured identification of its end points and protection of the channel data from modification or disclosure.

Application Note:

If “an IPsec” is selected, the Base-PP SFR FCS_IPSEC_EXT.1 must be claimed.

If "a RadSec" is selected, the selection-based SFR FCS_RADSEC_EXT.1 must be claimed.

If “a mutually authenticated TLS” is selected, the Base-PP SFRs FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2 must be claimed.

If “a mutually authenticated DTLS” is selected, the Base-PP SFRs FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2 must be claimed.

FTP_ITC.1.2/NAS

The TSF shall permit [the TSF, or the relying party] to initiate communication via the trusted channel.

FTP_ITC.1.3/NAS

The TSF shall initiate communication via the trusted channel for [responses to authentication request messages received from the relying party].

5.3 TOE Security Functional Requirements Rationale

The following rationale provides justification for each security objective for the TOE, showing that the SFRs are suitable to meet and achieve the security objectives:
Table 3: SFR Rationale
Objective Addressed by Rationale
O.AUTHORIZED_USE
FAU_GEN.1/AuthSvr The TOE implements an audit mechanism to detect potential misuse of the TOE.

FCS_CKM.3 The TOE implements a cryptographic key access control mechanism to prevent compromise of data in transit confidentiality mechanisms.

FCS_STG_EXT.1 The TOE implements a cryptographic key storage mechanism to prevent compromise of data in transit confidentiality mechanisms.

FIA_UAU.6 The TOE implements a re-authentication mechanism to prevent compromise of an administrator account to an unattended session.

FMT_SMF.1/AuthSvr The TOE implements management functions as a legitimate mechanism to control the behavior of the TSF.

O.SECURITY_ASSOCIATION
FCO_NRO.1 The TOE provides a non-repudiation function to assert the source of origin of its communications with the relying party.

FCO_NRR.1 The TOE provides a proof of receipt function to assert to a relying part that communications with it are successful.

FCS_EAPTLS_EXT.1 The TOE implements either EAP-TLS or EAP-TTLS as a mechanism to assert the success or failure of claimant authentication requests to the relying party.

O.TRUSTED_RP
FCS_EAPTLS_EXT.1 The TOE implements either EAP-TLS or EAP-TTLS with mutual authentication to authenticate itself to a relying party.

FTP_ITC.1/NAS The TOE implements a cryptographically secure trusted channel with a relying party that allows it to authorize itself to the relying party.

FCS_RADSEC_EXT.1 RadSec is one potential mechanism by which the TOE can establish a trusted channel with the relying party.

FIA_PSK_EXT.1/AuthSvr Depending on the configuration of the trusted channel used to communicate with the relying party, the TOE may use a pre-shared key as the mechanism by which it authenticates itself to the relying party.

O.USER_AUTH
FCS_RADIUS_EXT.1 The TOE implements RADIUS, DIAMETER, or some other direct identity federation protocol to communicate the success or failure of claimant authentication requests.

FIA_AFL.1/AuthSvr The TOE implements a mechanism to prevent claimant authentication attempts if an excessive number of failed attempts have been made.

FIA_X509_EXT.1/AuthSvr The TOE implements a mechanism to determine the validity of X.509 certificates that are used as claimant authenticators.

FTA_TSE.1 The TOE implements a mechanism to assert the failure of a claimant authentication attempt based on attributes of the claimant or of the attempt.

FIA_HOTP_EXT.1 The TOE optionally supports HOTP as a form of claimant authenticator and implements mechanisms to determine the validity of a HOTP credential if supported.

FIA_PSK_EXT.1/AuthSvr The TOE optionally supports PSKs as a form of claimant authenticator and may specifically support one or more of HOTP, TOTP, or password-based PSK.

FIA_PSK_EXT.2 The TOE optionally supports randomly generated PSKs as a form of claimant authenticator.

FIA_PSK_EXT.3 The TOE optionally supports password-based PSKs as a form of claimant authenticator and implements mechanisms to determine the validity of a password-based PSK credential if supported.

FIA_TOTP_EXT.1 The TOE optionally supports TOTP as a form of claimant authenticator and implements mechanisms to determine the validity of a TOTP credential if supported.

Table 3: SFR Rationale
Objective	Addressed by	Rationale
O.AUTHORIZED_USE	FAU_GEN.1/AuthSvr	The TOE implements an audit mechanism to detect potential misuse of the TOE.
FCS_CKM.3	The TOE implements a cryptographic key access control mechanism to prevent compromise of data in transit confidentiality mechanisms.
FCS_STG_EXT.1	The TOE implements a cryptographic key storage mechanism to prevent compromise of data in transit confidentiality mechanisms.
FIA_UAU.6	The TOE implements a re-authentication mechanism to prevent compromise of an administrator account to an unattended session.
FMT_SMF.1/AuthSvr	The TOE implements management functions as a legitimate mechanism to control the behavior of the TSF.
O.SECURITY_ASSOCIATION	FCO_NRO.1	The TOE provides a non-repudiation function to assert the source of origin of its communications with the relying party.
FCO_NRR.1	The TOE provides a proof of receipt function to assert to a relying part that communications with it are successful.
FCS_EAPTLS_EXT.1	The TOE implements either EAP-TLS or EAP-TTLS as a mechanism to assert the success or failure of claimant authentication requests to the relying party.
O.TRUSTED_RP	FCS_EAPTLS_EXT.1	The TOE implements either EAP-TLS or EAP-TTLS with mutual authentication to authenticate itself to a relying party.
FTP_ITC.1/NAS	The TOE implements a cryptographically secure trusted channel with a relying party that allows it to authorize itself to the relying party.
FCS_RADSEC_EXT.1	RadSec is one potential mechanism by which the TOE can establish a trusted channel with the relying party.
FIA_PSK_EXT.1/AuthSvr	Depending on the configuration of the trusted channel used to communicate with the relying party, the TOE may use a pre-shared key as the mechanism by which it authenticates itself to the relying party.
O.USER_AUTH	FCS_RADIUS_EXT.1	The TOE implements RADIUS, DIAMETER, or some other direct identity federation protocol to communicate the success or failure of claimant authentication requests.
FIA_AFL.1/AuthSvr	The TOE implements a mechanism to prevent claimant authentication attempts if an excessive number of failed attempts have been made.
FIA_X509_EXT.1/AuthSvr	The TOE implements a mechanism to determine the validity of X.509 certificates that are used as claimant authenticators.
FTA_TSE.1	The TOE implements a mechanism to assert the failure of a claimant authentication attempt based on attributes of the claimant or of the attempt.
FIA_HOTP_EXT.1	The TOE optionally supports HOTP as a form of claimant authenticator and implements mechanisms to determine the validity of a HOTP credential if supported.
FIA_PSK_EXT.1/AuthSvr	The TOE optionally supports PSKs as a form of claimant authenticator and may specifically support one or more of HOTP, TOTP, or password-based PSK.
FIA_PSK_EXT.2	The TOE optionally supports randomly generated PSKs as a form of claimant authenticator.
FIA_PSK_EXT.3	The TOE optionally supports password-based PSKs as a form of claimant authenticator and implements mechanisms to determine the validity of a password-based PSK credential if supported.
FIA_TOTP_EXT.1	The TOE optionally supports TOTP as a form of claimant authenticator and implements mechanisms to determine the validity of a TOTP credential if supported.

5.4 TOE Security Assurance Requirements

This PP-Module does not define any Security Assurance requirements. The SARs from the Base-PP must be satisfied.

6 Consistency Rationale

6.1 Collaborative Protection Profile for Network Devices

6.1.1 Consistency of TOE Type

When this PP-Module is used to extend the NDcPP, the TOE type for the overall TOE is still a network device. The TOE boundary is simply extended to include authentication server functionality that is provided by the network device.

6.1.2 Consistency of Security Problem Definition

PP-Module Threat, Assumption, OSP	Consistency Rationale
T.FALSE_ENDPOINTS	This threat is similar to the T.WEAK_AUTHENTICATION_ENDPOINTS threat in the NDcPP but it applies specifically to the NAS, which is an environmental component that is defined specifically in this PP-Module.
T.INVALID_USERS	This threat is similar to the T.UNAUTHORIZED_ADMINISTRATOR_ACCESS threat in the NDcPP but it applies to user authentication brokered by the TSF rather than to administrator authentication to the TOE itself. It is also similar to the T.UNTRUSTED_COMMUNICATION_CHANNELS threat in the NDcPP except that it applies specifically to the RADIUS communications and the protocols used to secure those, which is an interface that is defined specifically in this PP-Module.
A.RP_FEDERATION	The NDcPP does not define any assumptions for the intended network architecture that the TOE is deployed into. Therefore, an assumption that the network can be set up in such a way that the TOE will have direct connectivity with one or more relying parties does not violate any assumptions of the NDcPP.
P.AUTH_POLICY	This OSP relates to behavior that is not part of the Base-PP and so the Base-PP is not contradicted by guidance on its implementation.

6.1.3 Consistency of Objectives

The objectives for the TOEs are consistent with the NDcPP based on the following rationale:
PP-Module TOE Objective Consistency Rationale
O.AUTHORIZED_USE The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This TOE objective is intended to mitigate the T.UNAUTHORIZED_ADMINISTRATOR_ACCESS and T.UNDETECTED_ACTIVITY threats for the functions defined by this PP-Module.
O.SECURITY_ASSOCIATION The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.
O.TRUSTED_RP The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.
O.USER_AUTH The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.

PP-Module TOE Objective	Consistency Rationale
O.AUTHORIZED_USE	The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This TOE objective is intended to mitigate the T.UNAUTHORIZED_ADMINISTRATOR_ACCESS and T.UNDETECTED_ACTIVITY threats for the functions defined by this PP-Module.
O.SECURITY_ASSOCIATION	The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.
O.TRUSTED_RP	The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.
O.USER_AUTH	The NDcPP does not define any TOE objectives; instead, it maps SFRs directly to threats. This objective is therefore assumed not to conflict with the NDcPP by virtue of the fact that the SFRs used to satisfy this objective do not conflict with the NDcPP SFRs.

The objectives for the TOE's OE are consistent with the NDcPP based on the following rationale:
PP-Module OE Objective Consistency Rationale
OE.RP_FEDERATION The Base-PP does not define where in a particular network architecture a network device must be deployed since it is designed to be generic to various types of network devices. This PP-Module defines the expected architectural deployment specifically for a network device that acts as an authentication server.
OE.REQUIRE_AUTH The Base-PP does not define a particular use for a network device, so there is no consistency issue with the PP-Module defining expectations for the use of a specific type of device.

PP-Module OE Objective	Consistency Rationale
OE.RP_FEDERATION	The Base-PP does not define where in a particular network architecture a network device must be deployed since it is designed to be generic to various types of network devices. This PP-Module defines the expected architectural deployment specifically for a network device that acts as an authentication server.
OE.REQUIRE_AUTH	The Base-PP does not define a particular use for a network device, so there is no consistency issue with the PP-Module defining expectations for the use of a specific type of device.

6.1.4 Consistency of Requirements

This PP-Module identifies several SFRs from the NDcPP that are needed to support Authentication Server functionality. This is considered to be consistent because the functionality provided by the NDcPP is being used for its intended purpose. The PP-Module also identifies a number of modified SFRs from the NDcPP that are used entirely to provide functionality for Authentication Servers. The rationale for why this does not conflict with the claims defined by the NDcPP are as follows:

PP-Module Requirement	Consistency Rationale
Modified SFRs
FIA_X509_EXT.1/Rev	This PP-Module modifies the Base-PP's definition of the SFR by making it mandatory rather than selection-based.
FIA_X509_EXT.2	This PP-Module modifies the Base-PP's definition of the SFR by making it mandatory rather than selection-based.
FIA_X509_EXT.3	This PP-Module modifies the Base-PP's definition of the SFR by making it mandatory rather than selection-based.
Additional SFRs
This PP-Module does not add any requirements when the NDcPP is the base.
Mandatory SFRs
FAU_GEN.1/AuthSvr	This SFR iterates the FAU_GEN.1 SFR defined in the Base-PP to define auditable events for the functionality that is specific to this PP-Module.
FCO_NRO.1	This SFR applies to the implementation of the supported authentication protocol, which is beyond the original scope of the Base-PP.
FCO_NRR.1	This SFR applies to the implementation of the supported authentication protocol, which is beyond the original scope of the Base-PP.
FCS_CKM.3	The Base-PP requires confidentiality of cryptographic key data in FPT_SKP_EXT.1. This SFR defines more specific detail on how that function should be enforced.
FCS_EAPTLS_EXT.1	This SFR applies to the implementation of EAP-TLS; the Base-PP defines implementation requirements for (D)TLS, but EAP-TLS is beyond the original scope of the Base-PP.
FCS_RADIUS_EXT.1	This SFR applies to the implementation of authentication protocols, which is beyond the original scope of the Base-PP.
FCS_STG_EXT.1	This SFR is consistent with the FPT_SKP_EXT.1 requirement of the Base-PP but requires the TSF to implement a specific method of protecting key data rather than a general statement that such data is not stored in plaintext.
FIA_AFL.1/AuthSvr	This SFR defines functional behavior enforced on external users being authenticated by the TOE, which is functionality that is not covered by the Base-PP.
FIA_UAU.6	This SFR defines support for re-authentication of administrators, which expands on the authentication functionality defined in the Base-PP.
FIA_X509_EXT.1/AuthSvr	The Base-PP defines X.509 validation requirements for external entities presenting certificates to the TOE. This PP-Module defines a separate iteration of this function to define the certificate validation behavior that is enforced against claimants requesting to be authenticated by the TOE. It is substantially refined from its original definition to address issues specific to the handling of claimant certificates.
FMT_SMF.1/AuthSvr	This SFR defines additional management functionality that is specific to the PP-Module’s product type and would therefore not be expected to be present in the Base-PP.
FTA_TSE.1	This SFR relates to the handling of claimants being authenticated by the TOE, which is functionality that is beyond the original scope of the Base-PP.
FTP_ITC.1/NAS	This SFR iterates the FTP_ITC.1 SFR defined in the Base-PP to define trusted communication channels for the functionality that is specific to this PP-Module.
Optional SFRs
This PP-Module does not define any Optional requirements.
Objective SFRs
This PP-Module does not define any Objective requirements.
Implementation-based SFRs
This PP-Module does not define any Implementation-based requirements.
Selection-based SFRs
FCS_RADSEC_EXT.1	This SFR defines the implementation of RadSec and the peer authentication method that it uses. This relies on the TLS requirements defined by the Base-PP and may also use the X.509v3 certificate validation methods specified in the Base-PP, depending on the selected peer authentication method.
FIA_HOTP_EXT.1	This SFR extends the functionality of the Base-PP by defining the use of pre-shared keys as an authenticator.
FIA_PSK_EXT.1/AuthSvr	This SFR extends the functionality of the Base-PP by defining the use of pre-shared keys as an authenticator.
FIA_PSK_EXT.2	This SFR extends the functionality of the Base-PP by defining the use of pre-shared keys as an authenticator.
FIA_PSK_EXT.3	This SFR extends the functionality of the Base-PP by defining the use of pre-shared keys as an authenticator.
FIA_TOTP_EXT.1	This SFR extends the functionality of the Base-PP by defining the use of pre-shared keys as an authenticator.

Appendix A - Optional SFRs

A.1 Strictly Optional Requirements

This PP-Module does not define any Strictly Optional SFRs.

A.2 Objective Requirements

This PP-Module does not define any Objective SFRs.

A.3 Implementation-based Requirements

This PP-Module does not define any Implementation-based SFRs.

Appendix B - Selection-based Requirements

B.1 Cryptographic Support (FCS)

FCS_RADSEC_EXT.1 RadSec

The inclusion of this selection-based component depends upon selection in FTP_ITC.1.1/NAS .

FCS_RADSEC_EXT.1.1

The TSF shall implement RadSec as specified in [selection: RFC 6614, RFC 7360 ] as updated by RFC 8996 to communicate securely with a relying party.

FCS_RADSEC_EXT.1.2

The TSF shall perform relying party authentication using X.509v3 certificates in accordance with FIA_X509_EXT.1/Rev and [selection: pre-shared keys, no other methods ].

Application Note: It is recommended that both X.509v3 certificates and pre-shared keys be supported for resiliency purposes.

FCS_RADSEC_EXT.1.3

The TSF shall implement RadSec using [selection: TLS in accordance with FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2 from the Base-PP, DTLS in accordance with FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2 from the Base-PP ] with mutual authentication.

Application Note:

This SFR is claimed if "a RadSec" is selected in FTP_ITC.1.1/NAS .

If "RFC 6614" is claimed in the selection for FCS_RADSEC_EXT.1.1, "TLS in accordance with FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2 from the Base-PP" is claimed in FCS_RADSEC_EXT.1.3 .

If "RFC 7360" is claimed in the selection for FCS_RADSEC_EXT.1.1, "DTLS in accordance with FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2 from the Base-PP" is claimed in FCS_RADSEC_EXT.1.3 . Note that RFC 7360 is not directly updated by RFC 8996, but its references to DTLS 1.2 (RFC 6347) are.

It is the intent that TLS 1.0, TLS 1.1, and DTLS 1.0 (to include via downgrade as allowed in the original RFCs) are not allowed here.

If "pre-shared keys" is selected in FCS_RADSEC_EXT.1.2, the selection-based SFR FIA_PSK_EXT.1/AuthSvr must be claimed.

B.2 Identification and Authentication (FIA)

FIA_HOTP_EXT.1 HMAC-Based One-Time Password Pre-Shared Keys

The inclusion of this selection-based component depends upon selection in FCS_EAPTLS_EXT.1.3, FIA_PSK_EXT.1.2/AuthSvr .

FIA_HOTP_EXT.1.1

The TSF shall support HMAC-Based One-Time Password authentication (HOTP) in accordance with RFC 4226.

FIA_HOTP_EXT.1.2

The TSF shall generate a HOTP seed key according to FCS_RBG_EXT.1 of [selection: 128, 256 ] bits.

FIA_HOTP_EXT.1.3

The TSF shall generate a new HOTP seed key for each claimant to be authenticated.

FIA_HOTP_EXT.1.4

The TSF shall use [selection: SHA-1, SHA-256, SHA-384, SHA-512 ] with key sizes [assignment: key size (in bits) used in HMAC] and message digest sizes [selection: 160, 256, 384, 512 ] to derive a HOTP hash from the HOTP seed and counter.

FIA_HOTP_EXT.1.5

The TSF shall truncate the HOTP hash per FIA_HOTP_EXT.1.4 to create a HOTP of [selection:

administrator configurable character length of at least 6
preset character length of [selection: 6, 7, 8, 9, 10 ]

FIA_HOTP_EXT.1.6

The TSF shall [selection:

throttle invalid requests to [selection:
- administrator configurable value
- [assignment: value less than 10]
] per minute
lock the associated account after [selection: administrator configurable value, [assignment: value less than 10] ] failed attempts until [selection: an administrator unlocks the account, a configurable time period has elapsed ]

FIA_HOTP_EXT.1.7

The TSF shall not verify HOTP attempts outside of the counter look-ahead window of [assignment: a value less than or equal to three] [selection:

except for resynchronization
where a look-ahead window of [selection: a configurable value, [assignment: fixed value] ] is used to reset the counter but which is not considered a valid HOTP value
with no exception

FIA_HOTP_EXT.1.8

The TSF shall increment the counter after each successful authentication.

Application Note: This SFR is claimed if "HOTP" is selected in FCS_EAPTLS_EXT.1.3 or if "HMAC-based one-time password" is selected in FIA_PSK_EXT.1.2/AuthSvr .

The selection in FIA_HOTP_EXT.1.4 must be consistent with the key size specified for the size of the keys used in conjunction with the keyed-hash message authentication.

In FIA_HOTP_EXT.1.5, the ST author may either provide a configurable character length of at least 6 or a preset size between 6 and 10.

In FIA_HOTP_EXT.1.6, the ST may select throttle requests, account lockout, or both.

The selections in FIA_HOTP_EXT.1.7 indicate an optional resynchronization process that allows an arbitrary look-ahead to determine a new counter value by the verifier. This can be used for out-of-sync claimants or for initial use of a HOTP mechanism. The HOTP value presented for resynchronization does not serve to authenticate a user. A second verification using a small look-ahead window (at most three) is required after resynchronization to ensure the claimant and the TOE counter values are indeed synchronized so that arbitrary values are not considered valid. If such a resynchronization function is not supported, ‘with no exception’ is claimed.

The HOTP seed and all derived values are considered secret keys for purposes of protection.

FIA_PSK_EXT.1/AuthSvr Pre-Shared Key Usage (Claimant Authentication)

The inclusion of this selection-based component depends upon selection in FCS_EAPTLS_EXT.1.3, FCS_RADSEC_EXT.1.2 .

FIA_PSK_EXT.1.1/AuthSvr

The TSF shall be able to use pre-shared keys for [selection: IPsec, RadSec, EAP-TTLS, RADIUS, HOTP, TOTP ].

FIA_PSK_EXT.1.2/AuthSvr

The TSF shall be able to accept the following as pre-shared keys: [selection: generated bit-based, password-based, HMAC-based one-time password, time-based one-time password ].

Application Note: This SFR is claimed if any other TOE functions require the use of pre-shared keys. Within the scope of this PP-Module, this includes the following:

Any of "static PSK," "HOTP," or "TOTP" is selected in FCS_EAPTLS_EXT.1.3 .
"pre-shared keys" is selected in FCS_RADSEC_EXT.1.2 .
"pre-shared keys" is selected in FCS_IPSEC_EXT.1.13 (from the Base-PP).

IPsec is claimed in FIA_PSK_EXT.1.1/AuthSvr, if IPsec is claimed in FTP_ITC.1/NAS and the selection for FCS_IPSEC_EXT.1.13 in the Base-PP includes ‘pre-shared keys.’ PSK in IPsec may use any supported type of PSK – those supported are claimed in FIA_PSK_EXT.1.2/AuthSvr . Use of certificates in IPsec is preferred.

RadSec is claimed in FIA_PSK_EXT.1.1/AuthSvr, if RadSec is selected in FTP_ITC.1/NAS and the (D)TLS implementation in RadSec allows server-only authentication or supports a PSK ciphersuite. RadSec can use any type of PSK – those supported should be claimed in FIA_PSK_EXT.1.2/AuthSvr . Use of a mutually authenticated (D)TLS channel using certificate-based authentication is preferred.

If a pre-shared key is used in RADIUS to authenticate the relying party, RADIUS is claimed. It should not be claimed when RADIUS is used exclusively with RadSec since in that case, the legacy PSK used in RADIUS is replaced with a fixed value not used in authenticating the relying party. Use of a mutually authenticated channel using certificates to authenticate the relying party is preferred.

EAP-TTLS is claimed in FIA_PSK_EXT.1.1/AuthSvr if it is claimed in FCS_EAPTLS_EXT.1.1 and support for static PSK (alone or in combination) is indicated in FCS_EAPTLS_EXT.1.3 . When EAP-TTLS is claimed in FIA_PSK_EXT.1.1/AuthSvr, at least one of ‘password-based,’ ‘HMAC-based one-time password,’ or ‘time-based one-time password’ is claimed in FIA_PSK_EXT.1.2/AuthSvr . Multiple password types are claimed if the TSF supports validation of combinations of password types, even if presented in a single payload.

Note that even if presented by a claimant, PSK are ignored in EAP-TLS implementations.

HOTP or TOTP, respectively, are claimed if the respective entry is claimed in FCS_EAPTLS_EXT.1.3 and the TSF validates the HOTP or TOTP values presented in an authentication request. If claimed, the PSK represents the seed key value generated by the TOE and shared via out-of-band mechanisms with the claimant as well as the HOTP or TOTP values presented by a claimant to be validated; the ‘generated as bit-based PSK’ as well as the respective HOTP or TOTP entries are claimed in FIA_PSK_EXT.1.2/AuthSvr . The selection-based SFRs FIA_HOTP_EXT.1 and FIA_TOTP_EXT.1 must also be claimed if HOTP or TOTP are claimed, respectively.

Note that if HOTP or TOTP mechanisms are supported, but the values are only validated by an external entity, the HOTP or TOTP entries are not claimed in FIA_PSK_EXT.1/AuthSvr .

If "generated bit-based" is selected in FIA_PSK_EXT.1.2/AuthSvr, FIA_PSK_EXT.2 must be claimed.

If "password-based" is selected in FIA_PSK_EXT.1.2/AuthSvr, FIA_PSK_EXT.3 must be claimed.

FIA_PSK_EXT.2 Generated Pre-Shared Keys

The inclusion of this selection-based component depends upon selection in FIA_PSK_EXT.1.2/AuthSvr .

FIA_PSK_EXT.2.1

The TSF shall be able to [selection:

accept externally generated pre-shared keys
generate [selection: 128, 256 ] bit-based pre-shared keys via FCS_RBG_EXT.1.

Application Note: This SFR is claimed if "generated bit-based" is selected in FIA_PSK_EXT.1.2/AuthSvr .

Generated PSKs are expected to be shared between components via an out-of-band mechanism.

FIA_PSK_EXT.3 Password-Based Pre-Shared Keys

The inclusion of this selection-based component depends upon selection in FIA_PSK_EXT.1.2/AuthSvr .

FIA_PSK_EXT.3.1

The TSF shall support a PSK of up to [assignment: positive integer of 64 or more] characters.

FIA_PSK_EXT.3.2

The TSF shall allow PSKs to be composed of any combination of uppercase characters, lowercase characters, numbers, the following special characters: "!", "@", "#", "$", "%", "^", "&", "*", "(", and ")", and [selection: [assignment: other supported special characters], no other characters ].

FIA_PSK_EXT.3.3

The TSF shall perform Password-based Key Derivation Functions in accordance with a specified cryptographic algorithm HMAC-[selection: SHA-256, SHA-384, SHA-512 ], with [assignment: positive integer of 4096 or more] iterations, and output cryptographic key sizes [selection: 128, 256 ] bits that meet the following: [NIST SP 800-132].

FIA_PSK_EXT.3.4

The TSF shall not accept PSKs failing to meet [selection: an administrator-defined, a fixed ] password policy indicating the maximum PSK length consistent with FIA_PSK_EXT.3.1 and [selection: [assignment: password policy indicating minimum length and types of characters required], no additional password constraints ].

FIA_PSK_EXT.3.5

The TSF shall generate all salts using an RBG that meets FCS_RBG_EXT.1 and with entropy corresponding to the key size selected for PBKDF in FIA_PSK_EXT.3.3 .

FIA_PSK_EXT.3.6

The TSF shall require the PSK to be entered in accordance with the [selection: user authentication policy, protocol authentication requirement ].

FIA_PSK_EXT.3.7

The TSF shall [selection: provide a password strength meter, check the password against a denylist, perform no action to assist the user in choosing a strong password ].

Application Note: This SFR is claimed if "password-based" is selected in FIA_PSK_EXT.1.2/AuthSvr .

For FIA_PSK_EXT.3.1, the ST author assigns the maximum size of the PSK it supports; it must support at least 64 characters.

For FIA_PSK_EXT.3.2, the ST author assigns any other supported characters; if there are no other supported characters, they should select "no other characters."

For FIA_PSK_EXT.3.3, the ST author selects the parameters based on the PBKDF used by the TSF.

For FIA_PSK_EXT.3.4, if the minimum length is settable, then the ST author chooses "a value settable by the administrator." If the minimum length is not settable, the ST author fills in the assignment with the minimum length the PSK must be. This requirement is to ensure bounds work properly.

For FIA_PSK_EXT.3.7, the ST author may select one, both, or neither of the functions in alignment with NIST SP 800-63B.

FIA_TOTP_EXT.1 Time-Based One-Time Password Pre-Shared Keys

The inclusion of this selection-based component depends upon selection in FCS_EAPTLS_EXT.1.3, FIA_PSK_EXT.1.2/AuthSvr .

FIA_TOTP_EXT.1.1

The TSF shall support Time-Based One-Time Password (TOTP) authentication in accordance with RFC 6238.

FIA_TOTP_EXT.1.2

The TSF shall generate a TOTP seed according to FCS_RBG_EXT.1 of [selection: 128, 256 ] bits.

FIA_TOTP_EXT.1.3

The TSF shall generate a new TOTP seed for each claimant.

FIA_TOTP_EXT.1.4

The TSF shall use [selection: SHA-1, SHA-256, SHA-384, SHA-512 ] with key sizes [assignment: key size (in bits) used in HMAC] and message digest sizes [selection: 160, 256, 384, 512 ] bits to derive a TOTP hash from the TOTP seed and current time provided by NTP.

FIA_TOTP_EXT.1.5

The TSF shall truncate the TOTP hash per FIA_TOTP_EXT.1.4 to create a TOTP of [selection:

administrator configurable character length of at least 6
preset character length of [selection: 6, 7, 8, 9, 10 ]

FIA_TOTP_EXT.1.6

The TSF shall [selection:

throttle invalid requests to [selection: administrator configurable value, [assignment: value less than 10] ] per minute
lock the associated account after [selection: administrator configurable value, [assignment: value less than 10] ] failed attempts until [selection: an administrator unlocks the account, a configurable time period has elapsed ]

FIA_TOTP_EXT.1.7

The TSF shall set a time-step size of [selection, choose one of: a configurable number of, [assignment: a value less than or equal to 30] ] seconds.

FIA_TOTP_EXT.1.8

The TSF shall not validate a TOTP value calculated using a time drift of more than [selection, choose one of: a configurable value, [assignment: a value less than or equal to 3] ] time-steps.

FIA_TOTP_EXT.1.9

The TSF shall [selection, choose one of: allow resynchronization by recording time drift within the limit of FIA_TOTP_EXT.1.8, not permit resynchronization ].

Application Note: This SFR is claimed if "TOTP" is selected in FCS_EAPTLS_EXT.1.3 or if "time-based one-time password" is selected in FIA_PSK_EXT.1.2/AuthSvr .

The selection FIA_TOTP_EXT.1.4 must be consistent with the key size specified for the size of the keys used in conjunction with the keyed-hash message authentication.

In FIA_TOTP_EXT.1.5, the ST author may either provide a configurable character length of at least 6 or a preset size between 6 and 10.

In FIA_TOTP_EXT.1.6, the ST author may select throttle requests, account lockout, or both.

The TOTP seed and all derived values are considered secret keys for purposes of protection.

Appendix C - Extended Component Definitions

This appendix contains the definitions for all extended requirements specified in the PP-Module.

C.1 Extended Components Table

All extended components specified in the PP-Module are listed in this table:

**Table 4: Extended Component Definitions**
Functional Class	Functional Components
Cryptographic Support (FCS)	FCS_EAPTLS_EXT EAP-TLS Protocol FCS_RADIUS_EXT Authentication Protocol FCS_RADSEC_EXT RadSec FCS_STG_EXT Cryptographic Key Storage
Identification and Authentication (FIA)	FIA_HOTP_EXT HMAC-Based One-Time Password Pre-Shared Keys FIA_PSK_EXT Pre-Shared Keys FIA_TOTP_EXT Time-Based One-Time Password Pre-Shared Keys

C.2 Extended Component Definitions

C.2.1 Cryptographic Support (FCS)

This PP-Module defines the following extended components as part of the FCS class originally defined by CC Part 2:

C.2.1.1 FCS_EAPTLS_EXT EAP-TLS Protocol

Family Behavior

This family defines requirements for how the TSF implements the Extensible Authentication Protocol (EAP) and EAP-Transport Layer Security.

Component Leveling

FCS_EAPTLS_EXT.1, EAP-TLS Protocol, requires the TSF to implement EAP and EAP-TLS according to appropriate standards.

Management: FCS_EAPTLS_EXT.1

The following actions could be considered for the management functions in FMT:

Configuration of claimant verification data
Configuration of claimant authentication policy

Audit: FCS_EAPTLS_EXT.1

The following actions should be auditable if FAU_GEN Security audit data generation is included in the PP/ST:

Protocol failures
Successful and failed authentication of claimant

FCS_EAPTLS_EXT.1 EAP-TLS Protocol

Hierarchical to: No other components.

Dependencies to: FCS_RBG_EXT.1 Random Bit Generation

[FCS_TLSS_EXT.1 TLS Server Protocol Without Mutual Authentication, or

FCS_DTLSS_EXT.1 DTLS Server Protocol Without Mutual Authentication]

[FCS_TLSS_EXT.2 TLS Server Support for Mutual Authentication, or

FCS_DTLSS_EXT.2 DTLS Server Support for Mutual Authentication]

FIA_X509_EXT.1 X.509 Certificate Validation

FCS_EAPTLS_EXT.1.1

FCS_EAPTLS_EXT.1.2

The TSF shall generate random values used in the [selection: EAP-TLS, EAP-TTLS ] exchange using the RBG specified in FCS_RBG_EXT.1.

FCS_EAPTLS_EXT.1.3

The TSF shall support claimant authentication using certificates and [selection: static PSK, HOTP, TOTP, other authentication-verification methods via pass-through, no other methods ].

FCS_EAPTLS_EXT.1.4

The TSF shall not forward an EAP-Success response to the relying party if the client certificate is not valid according to FIA_X509_EXT.1, if the [selection: TLS, DTLS ] session is not established, or if any of [selection: PSK, HOTP value, TOTP value, no other authenticator ] required by the authentication policy are not provided or if any of the required authenticators presented in the authentication request is not valid.

C.2.1.2 FCS_RADIUS_EXT Authentication Protocol

Family Behavior

Components in this family define requirements for implementation of authentication protocols.

Component Leveling

FCS_RADIUS_EXT.1, Authentication Protocol, requires the TSF to implement the specified authentication protocols.

Management: FCS_RADIUS_EXT.1

The following actions could be considered for the management functions in FMT:

Ability to configure RADIUS shared secret
Ability to define authorized NAS

Audit: FCS_RADIUS_EXT.1

The following actions should be auditable if FAU_GEN Security audit data generation is included in the PP/ST:

Protocol failures
Success/failure of authentication

FCS_RADIUS_EXT.1 Authentication Protocol

Hierarchical to: No other components.

Dependencies to: FCS_EAPTLS_EXT.1 EAP-TLS Protocol

FCS_RADIUS_EXT.1.1

FCS_RADIUS_EXT.1.2

The TSF shall implement encapsulated EAP in accordance with FCS_EAPTLS_EXT.1 .

FCS_RADIUS_EXT.1.3

C.2.1.3 FCS_STG_EXT Cryptographic Key Storage

Family Behavior

Components in this family define requirements for secure storage of cryptographic keys.

Component Leveling

FCS_STG_EXT.1, Cryptographic Key Storage, requires the TSF to identify a mechanism used to securely store cryptographic keys.

Management: FCS_STG_EXT.1

The following actions could be considered for the management functions in FMT:

Configuration of cryptographic key storage

Audit: FCS_STG_EXT.1

There are no auditable events foreseen.

FCS_STG_EXT.1 Cryptographic Key Storage

Hierarchical to: No other components.

Dependencies to: None

FCS_STG_EXT.1.1

Persistent private and secret keys shall be stored within the TSF [selection:

encrypted within a hardware protected key
in a hardware cryptographic module
within an isolated execution environment protected by a hardware key

C.2.1.4 FCS_RADSEC_EXT RadSec

Family Behavior

Components in this family define requirements for the TSF to use RadSec to secure RADIUS data in transit.

Component Leveling

FCS_RADSEC_EXT.1, RadSec, defines implementation requirements for RadSec.

Management: FCS_RADSEC_EXT.1

The following actions could be considered for the management functions in FMT:

Configuration of trusted channel to relying party

Audit: FCS_RADSEC_EXT.1

There are no auditable events foreseen.

FCS_RADSEC_EXT.1 RadSec

Hierarchical to: No other components.

Dependencies to: FCS_RADIUS_EXT.1 Authentication Protocol

FCS_RBG_EXT.1 Random Bit Generation

[FIA_PSK_EXT.1 Pre-Shared Key Composition, or

FIA_X509_EXT.1 X.509 Certificate Validation]

FCS_RADSEC_EXT.1.1

The TSF shall implement RadSec as specified in [selection: RFC 6614, RFC 7360 ] as updated by RFC 8996 to communicate securely with a relying party.

FCS_RADSEC_EXT.1.2

The TSF shall perform relying party authentication using X.509v3 certificates in accordance with FIA_X509_EXT.1 and [selection: pre-shared keys, no other methods ].

FCS_RADSEC_EXT.1.3

The TSF shall implement RadSec using [selection: TLS in accordance with FCS_TLSS_EXT.1 and FCS_TLSS_EXT.2, DTLS in accordance with FCS_DTLSS_EXT.1 and FCS_DTLSS_EXT.2 ] with mutual authentication.

C.2.2 Identification and Authentication (FIA)

This PP-Module defines the following extended components as part of the FIA class originally defined by CC Part 2:

C.2.2.1 FIA_HOTP_EXT HMAC-Based One-Time Password Pre-Shared Keys

Family Behavior

Components in this family define requirements for the use of HMAC-based One-Time Password authentication, including generation methods and usage restrictions.

Component Leveling

FIA_HOTP_EXT.1, HMAC-Based One-Time Password Pre-Shared Keys, defines the implementation of HOTP.

Management: FIA_HOTP_EXT.1

The following actions could be considered for the management functions in FMT:

Ability to configure restrictions on the composition of pre-shared keys
Ability to configure restrictions on the validation of pre-shared keys

Audit: FIA_HOTP_EXT.1

The following actions should be auditable if FAU_GEN Security audit data generation is included in the PP/ST:

Generation of a HOTP seed key
Entity HOTP value comparison

FIA_HOTP_EXT.1 HMAC-Based One-Time Password Pre-Shared Keys

Hierarchical to: No other components.

Dependencies to: FCS_COP.1 Cryptographic Operation

FCS_RBG_EXT.1 Random Bit Generation

FIA_HOTP_EXT.1.1

The TSF shall support HMAC-Based One-Time Password authentication (HOTP) in accordance with RFC 4226.

FIA_HOTP_EXT.1.2

The TSF shall generate a HOTP seed key according to FCS_RBG_EXT.1 of [selection: 128, 256 ] bits.

FIA_HOTP_EXT.1.3

The TSF shall generate a new HOTP seed key for each claimant to be authenticated.

FIA_HOTP_EXT.1.4

FIA_HOTP_EXT.1.5

The TSF shall truncate the HOTP hash per FIA_HOTP_EXT.1.4 to create a HOTP of [selection:

administrator configurable character length of at least 6
preset character length of [selection: 6, 7, 8, 9, 10 ]

FIA_HOTP_EXT.1.6

The TSF shall [selection:

throttle invalid requests to [selection:
- administrator configurable value
- [assignment: value less than 10]
] per minute
lock the associated account after [selection: administrator configurable value, [assignment: value less than 10] ] failed attempts until [selection: an administrator unlocks the account, a configurable time period has elapsed ]

FIA_HOTP_EXT.1.7

The TSF shall not verify HOTP attempts outside of the counter look-ahead window of [assignment: a value less than or equal to three] [selection:

except for resynchronization
where a look-ahead window of [selection: a configurable value, [assignment: fixed value] ] is used to reset the counter but which is not considered a valid HOTP value
with no exception

FIA_HOTP_EXT.1.8

The TSF shall increment the counter after each successful authentication.

C.2.2.2 FIA_PSK_EXT Pre-Shared Keys

Family Behavior

Components in this family describe the requirements for pre-shared keys used for authentication.

Component Leveling

FIA_PSK_EXT.1, Pre-Shared Key Usage, defines the use and composition of pre-shared keys used for authentication.

FIA_PSK_EXT.2, Generated Pre-Shared Keys, defines the use and composition of generated pre-shared keys used for authentication.

FIA_PSK_EXT.3, Password-Based Pre-Shared Keys, defines the use and composition of password-based pre-shared keys used for authentication.

Management: FIA_PSK_EXT.1

The following actions could be considered for the management functions in FMT:

Ability to associate pre-shared keys with claimants or external entities

Audit: FIA_PSK_EXT.1

There are no auditable events foreseen.

FIA_PSK_EXT.1 Pre-Shared Key Usage

Hierarchical to: No other components.

Dependencies to: [FCS_EAPTLS_EXT.1 EAP-TLS Protocol, or

FCS_IPSEC_EXT.1 IPsec]

FIA_PSK_EXT.1.1

The TSF shall be able to use pre-shared keys for [assignment: protocols or authentication schemes that use pre-shared keys].

FIA_PSK_EXT.1.2

The TSF shall be able to accept the following as pre-shared keys: [assignment: types of supported pre-shared keys (e.g., randomly generated, password-based, OTP)].

Management: FIA_PSK_EXT.2

The following actions could be considered for the management functions in FMT:

Ability to generate pre-shared keys
Ability to accept pre-shared keys

Audit: FIA_PSK_EXT.2

There are no auditable events foreseen.

FIA_PSK_EXT.2 Generated Pre-Shared Keys

Hierarchical to: No other components.

Dependencies to: FIA_PSK_EXT.1 Pre-Shared Key Usage

FIA_PSK_EXT.2.1

The TSF shall be able to [selection:

accept externally generated pre-shared keys
generate [selection: 128, 256 ] bit-based pre-shared keys via FCS_RBG_EXT.1.

Management: FIA_PSK_EXT.3

The following actions could be considered for the management functions in FMT:

Ability to configure restrictions on the composition of pre-shared keys
Ability to configure restrictions on the validation of pre-shared keys

Audit: FIA_PSK_EXT.3

No auditable events are foreseen.

FIA_PSK_EXT.3 Password-Based Pre-Shared Keys

Hierarchical to: No other components.

Dependencies to: FCS_COP.1 Cryptographic Operation

FCS_RBG_EXT.1 Random Bit Generation

FIA_PSK_EXT.1 Pre-Shared Key Usage

FIA_PSK_EXT.3.1

The TSF shall support a PSK of up to [assignment: positive integer of 64 or more] characters.

FIA_PSK_EXT.3.2

FIA_PSK_EXT.3.3

FIA_PSK_EXT.3.4

FIA_PSK_EXT.3.5

The TSF shall generate all salts using an RBG that meets FCS_RBG_EXT.1 and with entropy corresponding to the key size selected for PBKDF in FIA_PSK_EXT.3.3 .

FIA_PSK_EXT.3.6

The TSF shall require the PSK to be entered in accordance with the [selection: user authentication policy, protocol authentication requirement ].

FIA_PSK_EXT.3.7

The TSF shall [selection: provide a password strength meter, check the password against a denylist, perform no action to assist the user in choosing a strong password ].

C.2.2.3 FIA_TOTP_EXT Time-Based One-Time Password Pre-Shared Keys

Family Behavior

Components in this family define requirements for the use of Time-Based One-Time password authentication, including generation methods and usage restrictions.

Component Leveling

FIA_TOTP_EXT.1, Time-Based One-Time Password Pre-Shared Keys, defines the implementation of TOTP.

Management: FIA_TOTP_EXT.1

The following actions could be considered for the management functions in FMT:

Ability to configure restrictions on the composition of pre-shared keys
Ability to configure restrictions on the validation of pre-shared keys

Audit: FIA_TOTP_EXT.1

The following actions should be auditable if FAU_GEN Security audit data generation is included in the PP/ST:

Generation of a TOTP seed key
Entity TOTP value comparison

FIA_TOTP_EXT.1 Time-Based One-Time Password Pre-Shared Keys

Hierarchical to: No other components.

Dependencies to: FCS_COP.1 Cryptographic Operation

FCS_RBG_EXT.1 Random Bit Generation

FIA_TOTP_EXT.1.1

The TSF shall support Time-Based One-Time Password (TOTP) authentication in accordance with RFC 6238.

FIA_TOTP_EXT.1.2

The TSF shall generate a TOTP seed according to FCS_RBG_EXT.1 of [selection: 128, 256 ] bits.

FIA_TOTP_EXT.1.3

The TSF shall generate a new TOTP seed for each claimant.

FIA_TOTP_EXT.1.4

The TSF shall use [selection: SHA-1, SHA-256, SHA-384, SHA-512 ] with key sizes [assignment: key size (in bits) used in HMAC] and message digest sizes [selection: 160, 256, 384, 512 ] bits to derive a TOTP hash from the TOTP seed and current time provided by NTP.

FIA_TOTP_EXT.1.5

The TSF shall truncate the TOTP hash per FIA_TOTP_EXT.1.4 to create a TOTP of [selection:

administrator configurable character length of at least 6
preset character length of [selection: 6, 7, 8, 9, 10 ]

FIA_TOTP_EXT.1.6

The TSF shall [selection:

throttle invalid requests to [selection: administrator configurable value, [assignment: value less than 10] ] per minute
lock the associated account after [selection: administrator configurable value, [assignment: value less than 10] ] failed attempts until [selection: an administrator unlocks the account, a configurable time period has elapsed ]

FIA_TOTP_EXT.1.7

The TSF shall set a time-step size of [selection, choose one of: a configurable number of, [assignment: a value less than or equal to 30] ] seconds.

FIA_TOTP_EXT.1.8

The TSF shall not validate a TOTP value calculated using a time drift of more than [selection, choose one of: a configurable value, [assignment: a value less than or equal to 3] ] time-steps.

FIA_TOTP_EXT.1.9

The TSF shall [selection, choose one of: allow resynchronization by recording time drift within the limit of FIA_TOTP_EXT.1.8, not permit resynchronization ].

Appendix D - Implicitly Satisfied Requirements

This appendix lists requirements that should be considered satisfied by products successfully evaluated against this PP-Module. These requirements are not featured explicitly as SFRs and should not be included in the ST. They are not included as standalone SFRs because it would increase the time, cost, and complexity of evaluation. This approach is permitted by [CC] Part 1, 8.2 Dependencies between components.

This information benefits systems engineering activities which call for inclusion of particular security controls. Evaluation against the PP-Module provides evidence that these controls are present and have been evaluated.

This PP-Module has no implicitly satisfied requirements. All SFR dependencies are explicitly met either through SFRs defined by the PP-Module or inherited from the Base-PP.

Appendix E - Allocation of Requirements in Distributed TOEs

For a distributed TOE, the SFRs in this PP-Module need to be met by the TOE as a whole, but not all SFRs will necessarily be implemented by all components. The following categories are defined in order to specify when each SFR must be implemented by a component:

All Components ("All"): All components that comprise the distributed TOE must independently satisfy the requirement.
At least one Component ("One"): This requirement must be fulfilled by at least one component within the distributed TOE.
Feature Dependent ("Feature Dependent"): These requirements will only be fulfilled where the feature is implemented by the distributed TOE component (note that the requirement to meet the PP-Module as a whole requires that at least one component implements these requirements if they are claimed by the TOE).

The table below specifies how each of the SFRs in this PP-Module must be met, using the categories above.

Requirement	Description	Distributed TOE SFR Allocation
FAU_GEN.1/AuthSvr	Audit Data Generation (Authentication Server)	All
FCO_NRO.1	Selective Proof of Origin	Feature Dependent
FCO_NRR.1	Selective Proof of Receipt	Feature Dependent
FCS_CKM.3	Cryptographic Key Access	All
FCS_EAPTLS_EXT.1	EAP-TLS Protocol	Feature Dependent
FCS_RADIUS_EXT.1	Authentication Protocol	Feature Dependent
FCS_STG_EXT.1	Cryptographic Key Storage	All
FIA_AFL.1/AuthSvr	Authentication Failure Handling (Claimant)	Feature Dependent
FIA_X509_EXT.1/AuthSvr	X.509 Certificate Validation (Claimant)	Feature Dependent
FIA_UAU.6	Re-Authenticating	Feature Dependent
FMT_SMF.1/AuthSvr	Specification of Management Functions (Authentication Server)	All
FTA_TSE.1	TOE Session Establishment	Feature Dependent
FTP_ITC.1/NAS	Inter-TSF Trusted Channel (Relying Party Communications)	Feature Dependent
FCS_RADSEC_EXT.1 (selection-based)	RadSec	Feature Dependent
FIA_HOTP_EXT.1 (selection-based)	HMAC-Based One-Time Password Pre-Shared Keys	Feature Dependent
FIA_PSK_EXT.1/AuthSvr (selection-based)	Pre-Shared Key Usage	Feature Dependent
FIA_PSK_EXT.2 (selection-based)	Generated Pre-Shared Keys	Feature Dependent
FIA_PSK_EXT.3 (selection-based)	Password-Based Pre-Shared Keys	Feature Dependent
FIA_TOTP_EXT.1 (selection-based)	Time-Based One-Time Password Pre-Shared Keys	Feature Dependent

Appendix F - Entropy Documentation and Assessment

The TOE does not require any additional supplementary information to describe its entropy sources beyond the requirements outlined in the Base-PP.

Appendix G - Acronyms

Acronym	Meaning
AAA	Authentication, Authorization, and Accounting
Base-PP	Base Protection Profile
CC	Common Criteria
CEM	Common Evaluation Methodology
cPP	Collaborative Protection Profile
CRL	Certificate Revocation List
CSP	Critical Security Parameters
DTLS	Datagram Transport Layer Security
EAP	Extensible Authentication Protocol
HOTP	Hash-Based One-Time Password
IPsec	Internet Protocol Security
MSK	Master Session Key
OCSP	Online Certificate Status Protocol
OE	Operational Environment
PBKDF	Password-Based Key Derivation Function
PP	Protection Profile
PP-Configuration	Protection Profile Configuration
PP-Module	Protection Profile Module
PSK	Pre-Shared Key
RADIUS	Remote Authentication Dial In User Service
RBG	Random Bit Generator
RP	Relying Party
SAR	Security Assurance Requirement
SFR	Security Functional Requirement
SSH	Secure Shell
ST	Security Target
TLS	Transport Layer Security
TOE	Target of Evaluation
TOTP	Time-Based One-Time Password
TSF	TOE Security Functionality
TSFI	TSF Interface
TSS	TOE Summary Specification
WLAN	Wireless Local Area Network

Appendix H - Bibliography

Identifier	Title
[CC]	Common Criteria for Information Technology Security Evaluation - Part 1: Introduction and General Model, CCMB-2017-04-001, Version 3.1 Revision 5, April 2017. Part 2: Security Functional Components, CCMB-2017-04-002, Version 3.1 Revision 5, April 2017. Part 3: Security Assurance Components, CCMB-2017-04-003, Version 3.1 Revision 5, April 2017.
[NDcPP]	collaborative Protection Profile for Network Devices, Version 2.2e, March 23, 2020
[NDcPP SD]	Supporting Document - Evaluation Activities for Network Device cPP, Version 2.2, December 2019

PP-Module for Authentication Servers

Revision History

Contents

1 Introduction

1.1 Overview

1.2 Terms

1.2.1 Common Criteria Terms

1.2.2 Technical Terms

1.3 Compliant Targets of Evaluation

1.4 TOE Boundary

1.5 Use Cases

2 Conformance Claims

3 Security Problem Description

3.1 Threats

3.2 Assumptions

3.3 Organizational Security Policies

4 Security Objectives

4.1 Security Objectives for the TOE

4.2 Security Objectives for the Operational Environment

4.3 Security Objectives Rationale

5 Security Requirements

5.1 NDcPP Security Functional Requirements Direction

5.1.1 Modified SFRs

5.1.1.1 Identification and Authentication (FIA)

FIA_X509_EXT.1/Rev X.509 Certificate Validation

FIA_X509_EXT.2 X.509 Certificate Authentication

FIA_X509_EXT.3 X.509 Certificate Requests

5.2 TOE Security Functional Requirements

5.2.1 Security Audit (FAU)

FAU_GEN.1/AuthSvr Audit Data Generation (Authentication Server)

5.2.2 Communications (FCO)

FCO_NRO.1 Selective Proof of Origin

FCO_NRR.1 Selective Proof of Receipt

5.2.3 Cryptographic Support (FCS)

FCS_CKM.3 Cryptographic Key Access

FCS_EAPTLS_EXT.1 EAP-TLS Protocol

FCS_RADIUS_EXT.1 Authentication Protocol

FCS_STG_EXT.1 Cryptographic Key Storage

5.2.4 Identification and Authentication (FIA)

FIA_AFL.1/AuthSvr Authentication Failure Handling (Claimant)

FIA_UAU.6 Re-Authenticating

FIA_X509_EXT.1/AuthSvr X.509 Certificate Validation (Claimant)

5.2.5 Security Management (FMT)

FMT_SMF.1/AuthSvr Specification of Management Functions (Authentication Server)

5.2.6 TOE Access (FTA)

FTA_TSE.1 TOE Session Establishment

5.2.7 Trusted Path/Channels (FTP)

FTP_ITC.1/NAS Inter-TSF Trusted Channel (Relying Party Communications)

5.3 TOE Security Functional Requirements Rationale

5.4 TOE Security Assurance Requirements

6 Consistency Rationale

6.1 Collaborative Protection Profile for Network Devices

6.1.1 Consistency of TOE Type

6.1.2 Consistency of Security Problem Definition

6.1.3 Consistency of Objectives

6.1.4 Consistency of Requirements

Appendix A - Optional SFRs

A.1 Strictly Optional Requirements

A.2 Objective Requirements

A.3 Implementation-based Requirements

Appendix B - Selection-based Requirements

B.1 Cryptographic Support (FCS)

FCS_RADSEC_EXT.1 RadSec

B.2 Identification and Authentication (FIA)

FIA_HOTP_EXT.1 HMAC-Based One-Time Password Pre-Shared Keys

FIA_PSK_EXT.1/AuthSvr Pre-Shared Key Usage (Claimant Authentication)

FIA_PSK_EXT.2 Generated Pre-Shared Keys

FIA_PSK_EXT.3 Password-Based Pre-Shared Keys

FIA_TOTP_EXT.1 Time-Based One-Time Password Pre-Shared Keys

Appendix C - Extended Component Definitions

C.1 Extended Components Table

C.2 Extended Component Definitions

C.2.1 Cryptographic Support (FCS)

C.2.1.1 FCS_EAPTLS_EXT EAP-TLS Protocol

Family Behavior

Component Leveling

Management: FCS_EAPTLS_EXT.1

Audit: FCS_EAPTLS_EXT.1

FCS_EAPTLS_EXT.1 EAP-TLS Protocol

FCS_EAPTLS_EXT.1.1