RDMAP/DDP Security Draft

1. RDMAP/DDP Security Draft draft-ietf-rddp-security-00.txt Jim Pinkerton, Ellen Deleganes, Allyn Romanow, Bernard Aboba

2. Agenda • Overview of the paper • Define Functional Model, including • Components • Attack paths • Identify threats • Define counter measures • What’s new in this version • Issues • What’s still to be done 58th IETF - Minneapolis, MN USA

3. Approach • Security analysis not constrained to any one implementation – examine the scope of implementations • The draft is relatively new – minimal review • Still sections left to be written 58th IETF - Minneapolis, MN USA

4. Functional Component Model Request Proxy Interface Privileged Resource Manager Application Control Interface Admin Privileged Application Non-Privileged Application Privileged Control Interface Privileged Data Interface Non-Privileged Data Interface RNIC Interface (RI) RNIC Engine firmware Internet 58th IETF - Minneapolis, MN USA

5. Functional Components • Privileged application • Assumed to not intentionally attack the system, but may be greedy for resources • Non-privileged application • Desire to provide benefits of RDMAP/DDP without introducing additional security risk • Not trusted, granted only a subset of the capabilities granted to a privileged application • Resource Manager • Controls allocation of “scarce” resources • Implements policies to detect and prevent DoS attacks 58th IETF - Minneapolis, MN USA

6. An RI in More Detail Host RI Completion Queue Async Event Queue Send Queue Receive Queue RDMA Read Request Queue Resources: Page Translation Table, STag Table, Connection Context Memory Network 58th IETF - Minneapolis, MN USA

7. Threats and Attack Classes • Spoofing • Connection hijacking • Unauthorized STag use • Tampering • Unauthorized modification of remote buffers • Information Disclosure • Unauthorized read access to remote buffers • Denial of Service • Consumption of “precious” resources • Elevation of Privilege • Loading FW onto the RNIC 58th IETF - Minneapolis, MN USA

8. Tampering • Remote Peer attempts to tamper with buffers on a Local Peer • Attempt to write outside of the buffer bounds • Modify buffer contents after indicating buffer contents are ready for use • Using multiple STags to access the same buffer 58th IETF - Minneapolis, MN USA

9. Information Disclosure • Remote peer attempts to improperly read information in buffers on a Local Peer • Use of RDMA Read to access stale data • Accessing buffer after transfer is over • Accessing unintended data through use of a valid STag • Using multiple STags to access the same buffer 58th IETF - Minneapolis, MN USA

10. Denial of Service • Resource consumption • Receive data buffers when pool is shared • Completion Queue entries • RDMA Read Request Queue • Untagged receive buffers • Remote invalidation of an STag across multiple connections 58th IETF - Minneapolis, MN USA

11. Tools for Counter Measures • Protection Domain • End-to-end authentication • Limiting scope of: • STag • Number of connections, amount of buffer advertised, time the buffer is advertised, randomly use the namespace • Buffer access rights • Write-only, Read-only, Write/Read • Completion Queue • One or more connections • Error generation/propagation • Resource manager 58th IETF - Minneapolis, MN USA

12. Counter Measures • Protection Domain (PD) • Data buffers associated with an STag can be accessed only through connections in the same PD • Limit CQ access to connections in the same PD • Limit STag scope • Limit SdTag usage to a single connection, or connections in the same PD • Limit the time the STag is valid by invalidating STag when data transfer is over • Limit the memory the STag can access by setting base and bounds to just the intended buffers 58th IETF - Minneapolis, MN USA

13. Counter Measures • Set appropriate buffer access rights • Enable only the rights needed (read only, write only or read/write) • Local peer only access for buffers that do not require remote access • Limit scope of error propagation/generation • Limit generation of error events to prevent event queue overflow • Resource Manager • Put allocation of scarce resource under control of a Resource Manager 58th IETF - Minneapolis, MN USA

14. Attacks & Countermeasures 58th IETF - Minneapolis, MN USA

15. What’s New • “Partial Trust” instead of “Trust” • Architecture model • Clarifications to existing components • RNIC data transfer initialization • RNIC data transfer (SQ, RQ) • RNIC Asynch Event Queue 58th IETF - Minneapolis, MN USA

16. What’s New (cont) • Clarifications for implementation flexibility • Multiple PDs in a single app • Consideration of additional attacks • Controlling Page Trans. Table mapping to a buffer • Shared STag – remote invalidate • Shared STag – remote peer consumes too many buffers 58th IETF - Minneapolis, MN USA

17. Combinations of Trust 58th IETF - Minneapolis, MN USA

18. Dimensions of Partial Trust • Primarily a tool to educate the non-IETF RDMA community on the risks of traditional RDMA (local and remote trust) • Within IETF the assumption is generally no remote trust, no local trust • Thus dimensions of trust could be simplified to just a local resource sharing issue • i.e. Are local resources shared between streams? • Should we remove dimensions of trust? 58th IETF - Minneapolis, MN USA

19. Outstanding Issues • Issues highlighted in the document • IPsec section • Summary table at the end • Clarify using PD as counter measure vs. PD resource limitation • Describe security issue with sharing resources for untagged receives before diving into evaluation of shared buffer pool vs. shared receive queue • Still open since Vienna • Resolve shared RQ security issues • Better document multiple client to single server with different trust model per client 58th IETF - Minneapolis, MN USA

20. Outstanding Issues • Other emails • Non-privileged Application being able to disable/enable an STag mapping without using the Privileged Resource Manager 58th IETF - Minneapolis, MN USA