PSU CSE 543 - Systems and Midterm Review (17 pages)

Previewing pages 1, 2, 3, 4, 5, 6 of 17 page document View the full content.
View Full Document

Systems and Midterm Review



Previewing pages 1, 2, 3, 4, 5, 6 of actual document.

View the full content.
View Full Document
View Full Document

Systems and Midterm Review

58 views


Pages:
17
School:
Pennsylvania State University
Course:
Cse 543 - Computer Security
Computer Security Documents

Unformatted text preview:

Lecture 18 Systems and Midterm Review CSE543 Fall 2007 Computer and Network Security Professor Jaeger October 30 2007 CSE543 Computer and Network Security Fall 2007 Professor Jaeger Understanding Data Lifetime What happens to data in a system Where do secrets go Handled by Hardware systems middleware applications drivers etc How to find leaks and solve them CSE543 Computer and Network Security Fall 2007 Professor Jaeger Page 2 Data Lifetime How long memory values reside on a system Allocate a buffer Assign a secret Free the buffer Q What happens to the memory during and after this cycle What happens to freed memory Data may be written elsewhere used for other purposes Q What s the threat model here Key and other secrets protection is paramount CSE543 Computer and Network Security Fall 2007 Professor Jaeger Page 3 Can t Be That Hard Typical solutions Zero the memory on free Pin memory so not written to swap Encrypted file systems Problems Compilers may not comply Zeroing code on free buffers is optimized out Crashes Incorrect features don t really pin memory Hibernation and Migration Write state of system Complex interactions of logging random number generation crash dumps error reporting etc CSE543 Computer and Network Security Fall 2007 Professor Jaeger Page 4 Understanding Approach Whole System Simulation TaintBochs extension of IA 32 simulator Key Ideas Shadow Memory Backup of all existing memory registers and main memory Propagation Policy If any byte of any input value is tainted then all bytes of the output are tainted Exceptional Cases Tainted lookup tables Add more tainting Constant functions Remove unnecessary tainting Tainted Inputs Device inputs all keyboard or patterns network Application state what data is tainted to the system CSE543 Computer and Network Security Fall 2007 Professor Jaeger Page 5 Analysis Log everything All changes in system state at any point in simulation System states Can generate the state of the system at any time Identify Data



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Systems and Midterm Review and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Systems and Midterm Review and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?