Operational Assurance
Role of Operational Assurance
Operational Assurance in the CC
Class ADO – Delivery and Operation
Class AGD – Guidance Documentation
Class AVA – Vulnerability Assessment

Role of Operational Assurance
As evaluation criteria, CC concentrates on activities during TOE development and evaluation
Current CC assurance classes don’t really address Operations, but they do consider hand-off from developer to user/operator
There are several efforts to produce assurance classes that assign evaluatable requirements to operator, administrator, and user activities

Operational Assurance in the CC
CC institutionalizes Operational Assurance through 3 Assurance Classes containing 8 Assurance Families
Delivery and Operation (ADO)
Delivery; Installation, Generation, and Startup
Guidance Documents (AGD)
Administrator Guidance; User Guidance
Vulnerability Assessment (AVA)
Covert Channel Analysis; Misuse; Strength Of TOE Security Functions; Vulnerability Analysis

Delivery and Operation (ADO)
Goal of Delivery and Operation is ensure that the TOE that customers operate is within the range of configurations that were evaluated.
The two Families in the Class are:
Delivery (ADO_DEL)
Installation, Generation and Startup (ADO_IGS)

Delivery
Focus is on ensuring that the TOE received by a customer is exactly the TOE that was shipped from the developer
Three Components, levelled on the basis of increasing requirements on the developer to detect and prevent modifications to the TOE during delivery.
Delivery Procedures
Detection of Modification
Prevention of Modification

Delivery Procedures
The developer shall document procedures for delivery of the TOE or parts of it to the user
The delivery documentation shall describe all procedures that are necessary to maintain security when distributing versions of the TOE to a user's site
The developer shall use the delivery procedures

Detection of Modification
The developer shall document procedures for delivery of the TOE or parts of it to the user
The delivery documentation shall describe how the various procedures and technical measures provide for the detection of modifications, or any discrepancy between the developer's master copy and the version received at the user site
The delivery documentation shall describe how the various procedures allow detection of attempts to masquerade as the developer, even in cases in which the developer has sent nothing to the user's site

Prevention of Modification
The developer shall document procedures for delivery of the TOE or parts of it to the user
The delivery documentation shall describe how the various procedures and technical measures provide for the prevention of modifications, or any discrepancy between the developer's master copy and the version received at the user site

Installation, Generation and Startup
Goals of Installation, Generation and Startup are to ensure that the TOE has been installed, generated, and started up in a secure manner as intended by the developer
i.e., a secure transition from the TOE's implementation representation being under configuration control to its initial operation in the user environment
Two Components, levelled on the basis of whether the TOE generation options are logged
Installation Generation and Start-up (IGS) Procedures
Generation Log

IGS Procedures
The developer shall document procedures necessary for the secure installation, generation, and start-up of the TOE
describe the steps necessary for secure installation, generation, and start-up of the TOE

Generation Log
The developer shall document procedures necessary for the secure installation, generation, and start-up of the TOE
describe procedures capable of creating a log containing the generation options used to generate the TOE in such a way that it is possible to determine exactly how and when the TOE was generated

Guidance Documents (AGD)
Goal of Guidance Documents is to ensure that the developer provides effective guidance to both administrators and users on their responsibilities for TOE security
The two Families in the Class are:
Administrator Guidance
User Guidance

Administrator Guidance
Goal of Administrator Guidance is to help administrators understand the security functions provided by the TOE, including both those functions that require the administrator to perform security-critical actions and those functions that provide security-critical information
One Component
Administrator Guidance

Administrator Guidance
The developer shall provide administrator guidance addressed to system administrative personnel that shall:
describe the administrative functions and interfaces available to the administrator of the TOE
describe how to administer the TOE in a secure manner
contain warnings about functions and privileges that should be controlled in a secure processing environment
describe all assumptions regarding user behaviour that are relevant to secure operation of the TOE
describe all security parameters under the control of the administrator, indicating secure values as appropriate
describe each type of security-relevant event relative to the administrative functions that need to be performed, including changing the security characteristics of entities under the control of the TSF
be consistent with all other documentation supplied for evaluation
describe all security requirements for the IT environment that are relevant to the administrator

User Guidance
Goal of User Guidance is to describe the security functions provided by the TSF along with instructions and guidelines, including warnings, for their secure use by non-administrative users
One Component
User Guidance

User Guidance
The developer shall provide user guidance that shall:
describe the functions and interfaces available to the non-administrative users of the TOE
describe the use of user-accessible security functions provided by the TOE
contain warnings about user-accessible functions and privileges that should be controlled in a secure processing environment
clearly present all user responsibilities necessary for secure operation of the TOE, including those related to assumptions regarding user behaviour found in the statement of TOE security environment
be consistent with all other documentation supplied for evaluation
describe all security requirements for the IT environment that are relevant to the user

Vulnerability Assessment (AVA)
Goal of Vulnerability Assessment is to assess residual TOE security risks arising from
intrinsic limitations of chosen security mechanisms
misuse or misconfiguration of chosen security mechanisms
flawed implementation of chosen security mechanisms
The four Families in the Class are:
Covert Channel Analysis (AVA_CCA)
Misuse (AVA_MSU)
Strength of TOE Security Functions (AVA_SOF)
Vulnerability Analysis (AVA_VLA)

Covert Channel Analysis
Goal of Covert Channel Analysis is to determine the existence and potential capacity of unintended signalling channels (i.e. illicit information flows) that may be exploited
Only applies if there are information flow SFRs
Three Components, levelled based on the rigor of the covert channel analysis
Covert Channel Analysis
Systematic Covert Channel Analysis
Exhaustive Covert Channel Analysis

Covert Channel Analysis
The developer shall conduct a search for covert channels for each information flow control policy.
The developer shall provide covert channel analysis documentation that shall:
identify covert channels and estimate their capacity
describe the procedures used for determining the existence of covert channels, and the information needed to carry out the covert channel analysis
describe all assumptions made during the covert channel analysis
describe the method used for estimating channel capacity, based on worst case scenarios
describe the worst case exploitation scenario for each identified covert channel

Systematic Covert Channel Analysis
The developer shall conduct a search for covert channels for each information flow control policy.
The developer shall provide covert channel analysis documentation that shall:
provide evidence that the method used to identify covert channels is systematic
Primary additional requirement here is that there be a systematic strategy for identifying and verifying covert channels

Exhaustive Covert Channel Analysis
The developer shall conduct a search for covert channels for each information flow control policy.
The developer shall provide covert channel analysis documentation that shall:
provide evidence that the method used to identify covert channels is exhaustive
“exhaustive” is meant to imply that there are strong arguments that following the CCA plan will uncover all covert channels that might exist

Misuse
Goal of Misuse is to determine whether the TOE can be configured or used in a manner that is insecure but that an administrator or user of the TOE would reasonably believe to be secure
Three Components, levelled on the basis of increasing evidence provided by the developer and the increasing rigour of analysis
Examination of Guidance
Validation of Analysis
Analysis & Testing for Insecure States

Examination of Guidance
The developer shall provide guidance documentation that shall:
 identify all possible modes of operation of the TOE (including operation following failure or operational error), their consequences and implications for maintaining secure operation
be complete, clear, consistent and reasonable
list all assumptions about the intended environment
list all requirements for external security measures (including external procedural, physical and personnel controls)

Validation of Analysis
The developer shall provide guidance documentation
The developer shall document an analysis of the guidance documentation
The analysis documentation shall demonstrate that the guidance documentation is complete

Analysis & Testing for Insecure States
No additional explicit developer requirements
Evaluator is required to perform independent testing to verify that the guidance documentation provides enough information to identify insecure TOE configurations

Strength of TOE Security Functions
Goal of Strength of TOE Security Functions is to qualify the strength of security mechanisms that can be attacked using quantitative or statistical analysis techniques in terms of the effort required to successfully mount the attack
One Component
Strength of TOE security function evaluation

Strength of TOE security function evaluation
For each mechanism identified in the ST as having a strength of TOE security function claim, the developer shall perform a strength of TOE security function analysis that shall show that:
Each mechanism meets or exceeds the minimum strength level defined in the PP/ST
Each mechanism meets or exceeds the specific strength of function metric defined in the PP/ST

Vulnerability Analysis
Goal of Vulnerability Analysis is to determine if vulnerabilities identified - during the evaluation of the construction and anticipated operation of the TOE or by other methods (e.g. by flaw hypotheses) - could allow users to violate the TSP
Four Components, levelled based on an increasing rigour of vulnerability analysis by the developer and the evaluator
Developer Vulnerability Analysis
Independent Vulnerability Analysis
Moderately Resistant
Highly Resistant

Developer Vulnerability Analysis
The developer shall perform and document an analysis of the TOE deliverables searching for obvious ways in which a user can violate the TSP
The documentation shall show, for all identified vulnerabilities, that the vulnerability cannot be exploited in the intended environment for the TOE
The developer shall document the disposition of obvious vulnerabilities

Independent Vulnerability Analysis
The developer shall perform and document an analysis of the TOE deliverables searching for ways in which a user can violate the TSP
The documentation shall justify that the TOE, with the identified vulnerabilities, is resistant to obvious penetration attacks

Moderately Resistant
The developer shall perform and document an analysis of the TOE deliverables searching for ways in which a user can violate the TSP
The evidence shall show that the search for vulnerabilities is systematic

Highly Resistant
The developer shall perform and document an analysis of the TOE deliverables searching for ways in which a user can violate the TSP
The analysis documentation shall provide a justification that the analysis completely addresses the TOE deliverables