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SECURING CYBERSPACE: THE OM-AM, RBAC AND PKI ROADMAP. Prof. Ravi Sandhu Laboratory for Information Security Technology George Mason University sandhu@gmu.edu www.list.gmu.edu. INTERNET INSECURITY. Internet insecurity spreads at Internet speed Morris worm of 1987
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SECURING CYBERSPACE: THE OM-AM, RBAC AND PKI ROADMAP Prof. Ravi Sandhu Laboratory for Information Security Technology George Mason University sandhu@gmu.edu www.list.gmu.edu
INTERNET INSECURITY • Internet insecurity spreads at Internet speed • Morris worm of 1987 • Password sniffing attacks in 1994 • IP spoofing attacks in 1995 • Denial of service attacks in 1996 • Email borne viruses 1999 • Distributed denial of service attacks 2000 • Internet insecurity grows at super-Internet speed • security incidents are growing faster than the Internet (which has roughly doubled every year since 1988)
INTERNET INSECURITY • Its only going to get worse
INTERNET SECURITY • There are no clear cut boundaries in modern cyberspace • AOL-Microsoft instant messaging war of 1999 • Hotmail password bypass of 1999 • Ticketmaster deep web links • ebay versus auction aggregators
SECURITY OBJECTIVES CONFIDENTIALITY disclosure INTEGRITY modification AVAILABILITY access USAGE-CONTROL purpose
AUTHORIZATION, TRUST AND RISK • Information security is fundamentally about managing • authorization and • trust so as to manage risk
SECURITY DOCTRINE • Prevent • Detect • Correct • Accept
SECURITY DOCTRINE • absolute security is impossible does not mean absolute insecurity is acceptable • security is a journey not a destination
SOLUTIONS • OM-AM • RBAC • PKI • and others
THE OM-AM WAY A s s u r a n c e What? Objectives Model Architecture Mechanism How?
LAYERS AND LAYERS • Multics rings • Layered abstractions • Waterfall model • Network protocol stacks • OM-AM
What? How? OM-AM AND MANDATORY ACCESS CONTROL (MAC) A s s u r a n c e No information leakage Lattices (Bell-LaPadula) Security kernel Security labels
What? How? OM-AM AND DISCRETIONARY ACCESS CONTROL (DAC) A s s u r a n c e Owner-based discretion numerous numerous ACLs, Capabilities, etc
What? How? OM-AM AND ROLE-BASED ACCESS CONTROL (RBAC) A s s u r a n c e Policy neutral RBAC96 user-pull, server-pull, etc. certificates, tickets, PACs, etc.
ROLE-BASED ACCESS CONTROL (RBAC) • A user’s permissions are determined by the user’s roles • rather than identity or clearance • roles can encode arbitrary attributes • multi-faceted • ranges from very simple to very sophisticated
RBAC SECURITY PRINCIPLES • least privilege • separation of duties • separation of administration and access • abstract operations
RBAC96IEEE Computer Feb. 1996 • Policy neutral • can be configured to do MAC • roles simulate clearances (ESORICS 96) • can be configured to do DAC • roles simulate identity (RBAC98)
RBAC1 ROLE HIERARCHIES RBAC2 CONSTRAINTS RBAC96 FAMILY OF MODELS RBAC3 ROLE HIERARCHIES + CONSTRAINTS RBAC0 BASIC RBAC
USER-ROLE ASSIGNMENT PERMISSION-ROLE ASSIGNMENT USERS ROLES PERMISSIONS ... SESSIONS RBAC0
... RBAC1 ROLE HIERARCHIES USER-ROLE ASSIGNMENT PERMISSION-ROLE ASSIGNMENT USERS ROLES PERMISSIONS SESSIONS
HIERARCHICAL ROLES Primary-Care Physician Specialist Physician Physician Health-Care Provider
Supervising Engineer Hardware Engineer Software Engineer Engineer HIERARCHICAL ROLES
Hardware Engineer’ Software Engineer’ Supervising Engineer Hardware Engineer Software Engineer Engineer PRIVATE ROLES
EXAMPLE ROLE HIERARCHY Director (DIR) Project Lead 1 (PL1) Project Lead 2 (PL2) Production 1 (P1) Quality 1 (Q1) Production 2 (P2) Quality 2 (Q2) Engineer 1 (E1) Engineer 2 (E2) Engineering Department (ED) PROJECT 1 PROJECT 2 Employee (E)
EXAMPLE ROLE HIERARCHY Project Lead 1 (PL1) Project Lead 2 (PL2) Production 1 (P1) Quality 1 (Q1) Production 2 (P2) Quality 2 (Q2) Engineer 1 (E1) Engineer 2 (E2) Engineering Department (ED) PROJECT 1 PROJECT 2 Employee (E)
EXAMPLE ROLE HIERARCHY Director (DIR) Project Lead 1 (PL1) Project Lead 2 (PL2) Production 1 (P1) Quality 1 (Q1) Production 2 (P2) Quality 2 (Q2) Engineer 1 (E1) Engineer 2 (E2) PROJECT 1 PROJECT 2
EXAMPLE ROLE HIERARCHY Project Lead 1 (PL1) Project Lead 2 (PL2) Production 1 (P1) Quality 1 (Q1) Production 2 (P2) Quality 2 (Q2) Engineer 1 (E1) Engineer 2 (E2) PROJECT 1 PROJECT 2
... RBAC3 ROLE HIERARCHIES USER-ROLE ASSIGNMENT PERMISSIONS-ROLE ASSIGNMENT USERS ROLES PERMISSIONS SESSIONS CONSTRAINTS
CONSTRAINTS • Mutually Exclusive Roles • Static: The same individual can never hold both roles • Dynamic: The same individual can never activate both roles in the same context • Mutually Exclusive Permissions • Cardinality Constraints on User-Role Assignment • Cardinality Constraints on Permissions-Role Assignment
What? How? OM-AM AND ROLE-BASED ACCESS CONTROL (RBAC) A s s u r a n c e Policy neutral RBAC96 user-pull, server-pull, etc. certificates, tickets, PACs, etc.
CLIENT-SERVERSERVER-PULL ARCHITECTURE Client Server Authorization Server Authentication Server
CLIENT-SERVER USER-PULL ARCHITECTURE Client Server Authorization Server Authentication Server
CLIENT-SERVER PROXY OR THREE-TIER Client Authorization Server Server Authentication Server
What? How? OM-AM AND ROLE-BASED ACCESS CONTROL (RBAC) A s s u r a n c e Policy neutral RBAC96 user-pull, server-pull, etc. certificates, tickets, PACs, etc.
Related Mechanisms • Cookies • in widespread current use for maintaining state of HTTP • becoming a standard • not secure • Public-Key Certificates (X.509) • support security on the Web based on PKI • standard • simply, bind users to keys • have the ability to be extended
Security Threats to Cookies • Cookies are not secure • No authentication • No integrity • No confidentiality • can be easily attacked by • Network Security Threats • End-System Threats • Cookie Harvesting Threats
Applications of Secure Cookies • User Authentication • Electronic Transaction • Pay-Per-Access • Attribute-based Access Control
X.509 Certificate • Digitally signed by a certificate authority • to confirm the information in the certificate belongs to the holder of the corresponding private key • Contents • version, serial number, subject, validity period, issuer, optional fields (v2) • subject’s public key and algorithm info. • extension fields (v3) • digital signature of CA • Binding users to keys • Certificate Revocation List (CRL)
Smart Certificates • Short-Lived Lifetime • More secure • typical validity period for X.509 is months (years) • the longer-lived certificates have a higher probability of being attacked • users may leave copies of the corresponding keys behind • No Certificate Revocation List (CRL) • supports simple and less expensive PKI
Smart Certificates • Containing Attributes Securely • Web servers can use secure attributes for their purposes • Each authority has independent control on the corresponding information • basic certificate (containing identity information) • each attribute can be added, changed, revoked, or re-issued by the appropriate authority • e.g., role, credit card number, clearance, etc.
Applications of Smart Certificates • Very similar to applications of secure cookies
THE OM-AM WAY A s s u r a n c e What? Objectives Model Architecture Mechanism How?
INTERNET INSECURITY • Its only going to get worse • But security is a fun and profitable business and will get more so