Objectives :

1. Overview of Security Standards in the GridCSE 225High PerformanceandComputational GridsSpring 2000Prepared Bykwalsh@ucsd.edu

2. Objectives: • Gain familiarity with computer and network security standards. • Gain understanding of security requirements in Grid environments. • Gain understanding of some standards based security technologies present in Grid environments. • Learn about various Grid security models and system approaches to security. • Learn about some test bed implementations of security enabled Grid projects.

5. Security Domains • Intradomain - internal to a given location or single organization. Contained security boundary. • Interdomain - encompasses two or more locations or organizations. Agreed on security boundaries and protocols between organizations.

6. Security - The Protection of Assets • Prevention: take measure that protect your assets from damage • Detection: take measures that allow you to detect when an asset has been damaged, and who caused the damage. • Reaction: take measures that allow you to recover your assets or recover from damage to your assets.

7. Computer Security • Confidentiality: prevention of unauthorized disclosure of information. • Integrity: prevention of unauthorized withholding of information. • Availability: prevention of unauthorized withholding of information or resources.

8. Network Security (1) • Trusted Networks • Identification and Authentication • Discretionary Access Control • Labels and Mandatory Access Control • Audit

9. Technology - Cryptography • DES (Data Encryption Standard) • DSA (Digital Signature Algorithm) • RSA (Rivest, Shamir, and Adelman) • Blowfish • IDEA (International Data Encryption Algorithm) • AES (Advanced Encryption Standard)

10. Technology - SSH (1) • SSH is a packet-based binary protocol that implements a transport layer security mechanism. • Encompasses authentication, key exchange, encryption, and integrity. • TCP/IP is used as the transport usually • Basically an end to end encrypted tunnel • SSH logins the most prevalent between domains.

11. Technology - SSH (2)

12. Technology - PGP • Pretty Good Privacy • Public Domain • Popular for email and email of files • PGP user builds key ring of all public keys he has been given. • When message of file received from contact, can decrypt if key is on key ring

13. Shortcomings of PGP in distributed systems • Reasonable basis for key management among friends, but once it passes the bounds of direct friends, the credibility becomes strained. • Example • Carol’s key is P1 signed with P2 • Alice’s key is P2 signed with P4 • Carol’s key is P1 signed with P5 • What is the last certificate said Carol’s key is P3 signed with P5?

14. Kerberos (1) • Supports authentication in distributed systems. • Used for authentication between intelligent processes, client to server tasks or workstation to other hosts. • Basis of Kerberos is central server that provides authenticated tokens, called tickets.

15. Kerberos(2)Initiating Kerberos Session

16. Kerberos (3)Obtaining a ticket to access file

17. Kerberos (4)Strengths • No password communicated on the network. • Cryptographic protection against spoofing. • Limited period of validity • Time stamps to prevent replay attacks • Mutual authentication

18. Kerberos (5)Shortcomings in distributed systems • Requires continuous availability of a trusted ticket granting service. • Authenticity of servers requires a trusted relationship between the ticket granting server and every server. • Requires timely transactions. • Subverted workstation can save and later replay user passwords. • Does not scale well.

19. Public Key Infrastructure (1) • PKI: consists of software and procedures put in place by an organization • Supports the use of Public Keys for authentication and identifying users, services, and confirming digital signatures. • Public keys usually conform to the X.509 standard for certificates, and usually are based on the RSA public/private key encryption algorithm

20. Public Key Infrastructure (2)Goals • Application enabler • Secure Sign-On • Secure “Single” Sign Security • End-User Transparency • Comprehensive Security

21. Public Key Infrastructure (3)Components and Services • Certification Authority • Certificate repository • Certificate Revocation • Key backup and recovery • Automatic key update • Key history management • Cross-certification • Support for non-repudiation • Time stamping • Client software

22. Public Key Infrastructure (4)Current Standards Activities • X.509 • PKIX • X.500 • LDAP • S/MIME • IPsec • TLS

23. Section Break • Security in Legion and Globus

24. Security in Legion (1)Design Principals • 1- As in the Hippocratic Oath, do no harm! • 2- Caveat emptor - let the buyer beware. • 3- Small is beautiful.

25. Security in LegionStandards • X.509 ? • Keberos ?

26. Security in LegionLegion Security Model

27. Security in Legion (2)Basic Concepts • Every object provides certain known member functions - MayI, CanI, Iam, and Delegate. (Can be defaulted to NIL.) • Two objects associated with each operation: a responsible agent (RA) and a calling agent (CA) • Every invocation of member function is performed in the context of a certificate which contains the Legion Object ID. Certificate digitally signed by maker

28. Security in Legion

29. Security in Legion • Legion users responsible for own security. • Object might trust that the CA is correct. • Policies defined by objects themselves. • Every class defines a special member function, MayI. • MayI defines the security objects for a class. • Every member function invocation permitted only if MayI sanctions it.

30. Security in LegionAutomatic invocation of outgoing calls

31. Security in Legion • Authentication aided by use of Legion certificates - based on public-key cryptography by default. Must know private key to authenticate. • MayI functions can code their own authentication protocols • Every Legion object required to supply special member function Iam for authentication purposes.

32. Security inLegion • Login establishes user identity and creates responsibility agent for user. • Login is building block for authentication and delegation. • Object can delegate new certificate to delegate rights. • Delegation policy defined by object.

33. Security in LegionFuture Work • Legion does not specify any particular encryption. Future standardization? • Legion eschews distinguished trusted objects - centralized key management server • Composition of a security policy

34. Security in Globus (1)Standards • Standards subscribed to: • Generic Security Services (GSS) RFC 2078 • Secure Socket Layer (SSL) • [SSleay] • Public Key Cryptography based on X.509 certificates • Kerberos

35. Security in Globus (2)

36. Security in Globus (3)Security Requirements • Single sign-on • Protection of credentials • Interoperability with local security solutions • Exportability • Uniform credentials/certification infrastructure • Support for secure group communication • Support for multiple implementations

37. Local Services Condor MPI TCP UDP LSF Easy NQE AIX Irix Solaris Layered Architecture Applications High-level Services and Tools GlobusView Testbed Status DUROC MPI MPI-IO CC++ Nimrod/G globusrun Core Services Nexus GRAM Metacomputing Directory Service Globus Security Interface Heartbeat Monitor Gloperf GASS

38. Security in Globus (4) • assumes grid consists of multiple trust domains • assumes resource pool and user population are large and dynamic • interoperate with local security solutions - local security policies differ • authentication exportable - cannot directly or indirectly require use of bulk privacy

39. Security in Globus (5) • uniform credentials/certification - a user will be associated differently with site it has access to single logon - number of processes used in a computation will be dynamic access control

40. Security in Globus (8)

41. Security in Globus (6)Grid Security Infrastructure • GSI provides authentication and data integrity (data signing, not encryption) services for Unix and Windows client/server programs • Can utilize an X.509 PKI • GSI library is layered on top of the SSLeay • Performs the X.509 certificate handling and SSL protocol.

42. User User Proxy Site 1 Process Process GRAM GRAM GSI GSI Process Process Ticket Process Process Public Key Kerberos CREDENTIAL Single sign-onvia “grid-id” Assignment of credentials to “user proxies” Globus Credential Mutual user-resource authentication Site 2 Mapping to local ids Authenticated interprocess communication GSSAPI: multiple low-level mechanisms Certificate

43. Security in Globus (7)

45. Summary • Computer security is machine access centric • Network security is network access centric • Grid security is application centric • Inter-domain communications based upon common security standards such as PKI. • Metacomputing approach that embrace security standards will be more widely adopted.