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Common Criteria Protection Profiles for PKI Products. Eric Rosenfeld SPYRUS 8 November 1999 CACR Information Security Workshop Third-Party Evaluation Criteria. SPYRUS Project Goal.
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Common Criteria Protection Profiles for PKI Products Eric Rosenfeld SPYRUS 8 November 1999 CACR Information Security Workshop Third-Party Evaluation Criteria
SPYRUS Project Goal Develop a single security evaluation standard against which all major Certificate Issuing and Management System (CIMS) products and service implementations can be evaluated
A Single Evaluation Standard • Customers want evaluation of products against a common standard • Provides for fair comparison of competing products • Use of evaluated products shows due diligence • Benefits vendors • Lets all compete on a level playing field • Should be usable to evaluate implementations of service providers • Evaluations against “custom criteria” defined in Security Targets (STs) do not allow comparison of “apples to apples”
Why Use Protection Profiles? • Common Criteria (CC) or Blank Sheet of Paper • CC gaining acceptance • CC is flexible enough to cover most PKI issues • Other CC work in PKI area: • Cloud Cover PPs (UK) • SPYRUS PP (Australia) • Entrust STs (US, UK, & Canada) • NIST security requirements (US) • Protection Profiles (PPs) offer best unbiased description of a technology family
PP Scope Decisions (1 of 4) • Functions of a CIMS: • Required: • Registration • Initialization • Certification • Revocation • Optional (although many products implement): • Key generation • Key update • Cross-certification • Certificate revocation notice distribution/publication • Certificate usage
PP Scope Decisions (2 of 4) • System versus Component • A Registration Authority is responsible for assisting in the registration process • How the CIMS functions are divided is left up to the developer of a given CIMS product • For example, key generation may be done by the CA or the RA • The PPs do not reject any partitioning of CIMS functions which result in the security requirements being met • Approach: CA system, because separate CA and RA profiles are not meaningful
PP Scope Decisions (3 of 4) • Operating System and Hardware: In or Out of Target Of Evaluation (TOE)? • Traditionally, TOE included the OS and hardware • This can increase the cost of an evaluation • Use of products developed by other companies means that evaluators may not have access to the required evidence • Approach: Define required OS and hardware features as part of Security Environment/Security Assumptions • Evaluators determine that OS provides required features, by • Reference to an existing evaluation of the OS, or • By examining the required OS features themselves
PP Scope Decisions (4 of 4) • How to Handle Cryptography • CC sections on Cryptography are insufficient • Approach: • Cryptographic module outside of TOE; must be evaluated against FIPS 140-1 or equivalent standard • This allows vendors to get a single evaluation that is covered by the Mutual Recognition Agreement • Cryptographic modules can then be evaluated in each country using the relevant standards • Potentially some cryptographic functions in TOE (e.g., key distribution) • Have to fit in some CC requirements for these functions
Threats • Threat categories: • Threats from the CA • Threats from privileged users of the system (System Administrator) • Threats from the RA • Threats from “incidental bystanders” • Threats from attackers on the network • Threats from malicious subscribers • Threats from developers
IT Security Objectives • IT Security objectives for the TOE and/or its platform: • Identification/Authentication of users • Control of access to CIMS resources • Audit • Object reuse/residual information • Correct operation • TOE health checks • Data confidentiality • Data integrity
SPYRUS Approach • Protection Profiles for Four Levels of Products • Modeled after FIPS 140-1 structure • Increasing Functionality and Assurance Requirements • Designed to meet increasing levels of threat • Level 1: resists no/minimal threats by itself • Level 2: resists some threats over network • Level 3: resists most network threats; some threats from malicious local users • Level 4: resists most threats from network and local users
Level 1 (1 of 2) • Not resistant to any significant threat • Relies entirely on its Operating System and Environment for protection • FIPS 140-1 level 1 cryptographic module • Relatively easy to achieve by developers who document their processes and procedures • Evaluation should be quick, easy, and inexpensive
Level 1 (2 of 2) • Minimal Functional Security Requirements • FAU_GEN.1 Audit data generation • FAU_GEN.2 User identity association • FAU_SAR.1 Audit review • FAU_SAR.2 Restricted audit review • FAU_STG.1 Protected audit trail storage • FCO_NRO.1 Selective proof of origin • FIA_AFL.1 Authentication failure handling • FIA_UAU.2 User authentication before any action • FIA_UID.2 User identification before any action • FMT_SMR.1 Security roles • FPT_STM.1 Reliable time stamps
Level 2 (1 of 2) • Resists some threats occurring over the network • Relies on its OS and Environment for protection from all local threats • FIPS 140-1 level 2 cryptographic module • Achievable by developers today, but with some additional effort • Evaluations should be relatively quick and relatively inexpensive
Level 2 (2 of 2) • Increased Functional Security Requirements • Additions to Level 1: • FAU_SEL.1 Selective audit • FDP_ACC.1 Subset access control • FDP_ACF.1 Security attribute based access control • FDP_IFC.1 Subset information flow control • FDP_IFF.1 Simple security attributes • FDP_ITT.1 Basic internal transfer protection • FDP_ITT.3 Integrity monitoring • FMT_MSA.1 Management of security attributes • FMT_MTD.1 Management of TSF data • FPT_AMT.1 Abstract machine testing
Level 3 (1 of 2) • Resists most threats occurring over the network, and some threats from malicious local users • Relies on OS and Environment for protection from rest of the local threats • FIPS 140-1 level 2 cryptographic module • Difficult today, but achievable in high assurance development environments • Evaluation should be straightforward, but will be more time consuming and more expensive
Level 3 (2 of 2) • Increased Functional Security Requirements • Additions to Level 2: • FAU_SEL.1 Selective audit • FDP_RIP.1 Subset residual information protection • FDP_SDI.1 Stored data integrity monitoring • FDP_DAU.1 Basic data authentication • FDP_ETC.1 Export of user data without security attributes • FDP_ITC.1 Import of user data without security attributes • FTP_TRP.1 Trusted path
Level 4 (1 of 2) • Resists most threats occurring over the network and from local users • Minimal reliance on OS and Environment for protection from local threats • FIPS 140-1 level 3 cryptographic module • Stretch level; probably not achievable today, but may be achievable within five years • Evaluation will be complicated, will take many months, and cost a significant amount
Level 4 (2 of 2) • Stringent Functional Requirements • Increased from Level 3: • FDP_ACC.2 Complete access control • From FDP_ACC.1 Subset access control • FDP_IFC.2 Complete information flow control • From FDP_IFC.1 Subset information flow control • FDP_RIP.2 Full residual information protection • From FDP_RIP.1 Subset residual information protection • FDP_SDI.2 Stored data integrity monitoring and action • From FDP_SDI.1 Stored data integrity monitoring • Additions to Level 3: • FMT_MSA.2 Secure security attributes • FMT_MSA.3 Static attribute initialization
Assurance Packages • Based on CC Assurance Packages • Level 1: Low assurance EAL-1 + • EAL-1 plus ATE_FUN.1, Functional Testing • Level 2: Moderate assurance EAL-3 - • All of EAL-3 except ALC_DVS.1, Identification of Security Measures • Level 3: High assurance EAL-4 • EAL-4 (no additions or subtractions) • Also recommend ADV_INT.1, Modularity • Level 4: Advanced assurance EAL-6 - • All of EAL-6 except AVA_CCA.2, Systematic Covert Channel Analysis
Status • Second draft of PPs completed 15 March 99 • Sent for review to interested parties: • Microsoft • SAIC • Entrust • NIST • NSA • Interaction and feedback • Comments generally positive
Future Plans • Proposing an ANSI X9 New Work Item • Register PPs with NIAP (NIST/NSA) once registration process is developed • Gain international acceptance
Getting the Documents • Documents available at: • http://www.spyrus.com/documents/index.html
For more information (408) 327-1901Santa Clara, CA info@spyrus.com http://www.spyrus.com