Integrity Through Mediated Interfaces

PI Meeting July 24, 2001

Bob Balzer, Marcelo TallisTeknowledge

<balzer,mtallis>@teknowledge.comLegend: Turquoise Changes from July 99 PI meeting

Green Changes from Feb 00 PI meetingRed Changes from July 00 PI meetingBrown Changes from Feb 01 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

• PowerPoint and Word

• 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

MS Word Data Integrity Technical Approach To Attribution

• Time Lever shows document development– User selects range of interest– Move Forwards through Operations Log– Move Backwards through Undo Stack

Operations Log

MS Word Data Integrity Major Challenges

• Complexity of Word– 1128 unique commands– 889 Command Bar controls– 416 classes with 2594 instance variables– However only a small subset is commonly used

• Lack of a General Mechanism for Capturing User Operations– Each individual Word function is handled in a specific

implementation.

MS Word Data Integrity

User Operation Capture Completion StrategyGeneric Architecture

• Detect UnInstrumented User Changes– Method: Unmediated change to Undo Stack

• Record Modification1. Localize Scope of Change2. Compare with Cached State3. Record Scoped Change

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

• Operation Coverage– Compound Operations (Undo,AutoCorrect)– Recording “Uninstrumented” Operations– Insert Images/Symbols, Page/Section BreaksDemo

• Attribution– Forward-Backward Time ControlDemo

PowerPoint Data IntegrityPlan

• Reuse existing capabilities– Corruption Detection Wrapper– Recording/Replay Mechanism– Office2000 Instrumentation– (PowerPoint) Design Editor Change Monitor– Generic Data Integrity Architecture

• Unique Development– Instrument Remaining PowerPoint Operations

PowerPoint Data IntegrityStatus

• Using Generic Data Integrity Architecture– Handled

• Shape creation/deletion• Shape move/resize/recolor/rotate• Connector attachment/detachment• Group/ungroup

• Problems (requiring unique development)– Single Process Debug/Demo Architecture– Typed Text (different low-level implementation)– Dangling Connectors (incomplete COM model)

Data Integrity To Do

• MS Word Data Integrity– Finish set of commonly used operations (from survey)– Default mechanism to handle non instrumented changes– Finish Attribution

• Power Point Data Integrity– We expect significant reuse of Word instrumentation

• Demonstrate Data Integrity in Military System– Identify mission critical Word/PowerPoint use– Package system for test deployment

SafeEmail Attachments

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WrapperSafetyRulesk

AttachmentHandler

Spawn

• Wrapper encapsulateseach spawned process

SafeEmail Attachments

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WrapperSafetyRulesj

AttachmentHandler

• Each opened attachment spawns new process

SpawnSafeEmail Attachments

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WrapperSafetyRulesi

Attachment

Attachment

EmailClient

Safe EmailAttachments

No updatefor novelattacks

Safe Email AttachmentsWrapper

• Wrapper protects email attachment execution– Automatically spawned when attachment opened– Restricts (via application-specific rules)

• 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• COM Servers that can be contacted• Devices that can be used• Processes that can be accessed

– Detects scripts within application (different rules)• Pilot deployment within DARPA ATO office

Demo

Safe Email Attachments Accomplishments To Date

• 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

• Email Attachment Context Determined• Alerts Logged with Context• AIA Experiment conducted with IMSC(Musman)

Required for Deployment

Safe Email Attachments• Testing Status

– Functionality Testing (MitreTek): Completed– Rule Testing (MitreTek): Completed

• Allows normal behavior (Absence of False Positives)• Blocks malicious behavior

• To Do– Packaging for Deployment

• Installation• Documentation• Test for proper installation

– Implement Switch-Rules– Each attachment opened in separate process (hard)– Protect additional Resources (devices, COM)

Safe Email Attachments

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

AprJun

BBN => MARFORPAC

(NT => Win2000)

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

WordDec01: PowerPoint