Integrity Through Mediated Interfaces

PI Meeting: July 19-21, 2000

Bob Balzer

Teknowledge

balzer@teknowledge.com

Legend: Turquoise Changes from July 99 PI meetingGreen Changes from Feb 00 PI meeting

Technical Objectives

• Wrap Data with Integrity Marks– Insure its Integrity– Record its processing history– Reconstruct it from this history if it is corrupted

• by program bugs

• by malicious attacks

• Demo these capabilities on major COTS product– Microsoft Office Suite (PowerPoint & Word only)– Also demo on a mission critical military system

This Slide Intentionally Blank

Existing Practice

• Integrity Stove-Piped on Tool-by-Tool Basis

• End-to-End Integrity Not Supported

• Persistent Data only Safeguarded by OS

• Corruption Detection is Ad-Hoc

• Corruption Repair– Based on Backups– Not Integrated with Detection

• Wrap Program– Detect access of integrity marked data & decode it

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Mediation Cocoon

Environment = Operating System External Programs

Program

ChangeMonitor

– Monitor User Interface to detect change actions• Translate GUI actions into application specific modifications

Technical Approach

– Detect update of integrity marked data • Re-encode & re-integrity mark the updated data

• Repair any subsequent Corruption from History• Build on existing research infrastructure

Major Risks and Planned Mitigation

• Ability to detect application-level modificationsApplication Openness Spectrum:– Event-Generators: Capture as transaction history– Scripting API: Examine state to infer action– Black-Box: Mediate GUI to infer action=> Generic Mediators + Tool Specific mapping

Two Level ArchitectureM

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Mediation Cocoon

Environment = Operating System External Programs

Program

ChangeMonitor

1. Application Independent GUI Monitor signals action types

2. Application Dependent Change Monitor• Determines Action Parameters

• Logs Modification History

Major Risks and Planned Mitigation

• Ability to detect application-level modificationsApplication Openness Spectrum:– Event-Generators: Capture as transaction history– Scripting API: Examine state to infer action– Black-Box: Mediate GUI to infer action=> Generic Mediators + Tool Specific mapping

• Ability to protect transaction history=> Hide the location of the transaction history

• Virtual File System wrapper• System-level Randomization Techniques

• Tool-Specific Modification Trackers Expensive=> Automate common portions=> Provide rule-based scripting language

Accomplishments To Date

• Corruption Detector– IDs Document Version on Save (in Document)– Records Document Cryptographic Digest on Save– Checks Document Cryptographic Digest on Load

Demo

Demo

• Change Monitor for MS Word 2000– Determines parameters for application-level action– Records transaction history (for possible Replay)

• Corruption Repairer– Rebuilds document by replaying transaction history

Demo

Accomplishments To DateSafe Email Attachments

• Wrapper protects email attachment execution– Automatically spawned when attachment opened– Restricts

• Files that can be read/written• Remote Sites that can be downloaded-from/uploaded-to• Portions of Registry that can be read/written• Processes that can be spawned

Demo

• Planned Deployment– Aug: Alpha at Teknowledge/MitreTek– Sept: Beta at DARPA– Nov: Pilot at military command (TBD)

Accomplishments To DateIFE 2.3 ReRun Experiment (IA)

• 14 Blue Flags established (asset targets)• 12 captured by Red-Team• 2 uncaptured (protected by NT Wrappers)

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Accomplishments To DateOther IA Projects

• IFE 2.3 ReRun: only uncaptured blue flags

• NT Security Manager– Policy specifies

• which processes can run• whether executables should be integrity checked• how processes should be wrapped

– All processes wrapped before execution• New AIA Project :Enterprise Wrappers (Tek/ NAI)

– Goal: Network Management of Host Wrappers Common NT/Linux Interface & Infrastructure

Measures of Success

• Widespread Deployment of Integrity Manager for MS-Office

• Extensibility of Integrity Manager to other COTS products

• Ease of creating Modification Trackers• Resistance to Malicious Attacks

– Corruption Avoidance– Corruption Detection– Corruption Repair=> Red-Team Experiment

Expected Major Achievements

• for Integrity Marked Documents:– End-To-End Data Integrity (through multiple tools/sessions)

– Modifications Monitored, Authorized, & Recorded• Authorization Control of Users, Tools, and Operations • All Changes Attributed and Time Stamped

– Assured Detection of Corruption– Ability to Restore Corrupted Data

• Ability to operate with COTS products• MS-Office Documents Integrity Marked• Mission Critical Military System Integrity Marked

Task Schedule

• Dec99: Tool-Level Integrity Manager– Monitor & Authorize Tool access & updates

• Jun00: Operation-Level Integrity Manager – Monitor, Authorize, & Record Modifications

• Dec00: Integrity Management for MS-Office• Jun01: Corruption Repair• Dec01: Integrity Management for

Mission Critical Military System• Jun02: Automated Modification Tracking

Task ScheduleSafe Email-Attachments

• July00: Demo at PI Meeting

• Aug00: Alpha at Teknowledge/MitreTek

• Sept00: Beta at DARPA

• Nov00: Pilot at military command (TBD)

Enforced Policies• MS Word documents (PowerPoint next)

– Attack: Document corrupted between usages– Policy: Check integrity when used. Rebuild if corrupted– Attack: Insider corrupts document using Word/PowerPoint– Policy: Log changes. Attribute changes to individuals

• Suspect Programs– Attack: Program may harm persistent resources– Policy: Copy files just before they are modified.

Rollback when requested• Email-Attachments (Web Browsers)

– Attack: Program may harm resources– Policy: Restrict access/modification of resources

• Executables– Attack: Unauthorized changes are made to executables– Policy: Integrity Check executables before loading

Prohibit unauthorized modification of executables

(To Be) Enforced Policies

• <Program> can only modify files it creates

• <Program> can’t leave any persistent files after it terminates

• <Program> can only create/access files in <directory> that are selected by user

Key Outstanding Issues

• None Yet

Transition of Technology

• Piggyback our Technology on a widely used Target Product (MS Office)– Integrity Manager automatically invoked as needed

• Make technology available for COTS products

• Work with Vendors to encouragepublication of modification events

Needed PM Assistance

• Help identifying suitable mission critical military system (possibly at PACOM)