AAVS Middleware Security Group Bob Cowles CERN – September 14, 2005

2 Proxy Certificates Self-signed by an end-entity – not normally acceptable RFC 3820 defines motivation and usage Private key not protected except by file system security No CRL

3 Compromise Mitigations Only a single user Limited lifetime Does not compromise the original end- entity certificate Can be restricted in usage

4 Drawbacks Actual Use Lifetime may not be very limited No real agreement on renewal process Little use of limiting capabilities

5 Moving Ahead Renewal Can enforce limited lifetime constraint If application error, things don’t work and the bug gets fixed However –Proxy still exposed for inappropriate use until it expires –Significant resources can e consumed that are wasted

6 Moving Ahead Revocation Can use OCSP for “lighter weight” and more timely revocation Allows for more prompt revocation of compromised proxys However –Application may not be able to get information from server –Increased complexity of certificate validation

7 Moving Ahead Path forward is not clear Will need to use experience Need to maintain flexibility Need to increase security of checks from compromise If we have strong auth structure, do we even care about revoking authentication?

8 AAVS AA Validation Service Start with standard API of library routines for applications to call Move as quickly as possible to external service Eases load on application developers More flexibility as new requirements are discovered

9 Comments Discussion?