Paranoid Penguin - Limitations of shc, a Shell Encryption Utility

The shell script compiler, shc, obfuscates shell scripts with encryption—but the password is in the encrypted file. Could an intruder recover the original script using objdump?

An approach to extract the shell source code successfully from shc version 3.7 generated binary executable was demonstrated. The script was used for illustrative purposes only. I have indeed tested the deshc program on executables that I did not create and without access to the source code or the original shell script.

Francisco García, the author of shc, recently released version 3.8. It uses somewhat different data structures and improves upon the security of the previous version. Nevertheless, I believe that embedding the encryption password within the binary executable is dangerous and prone to extraction as discussed in this article.

Nalneesh Gaur, CISSP, ISAAP, works at Diamond Cluster International as a BS7799 Lead Auditor.



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

How to work with octave scripts ?

spiriad's picture

How to make it work with octave scripts, knowing the first line in is #! /usr/bin/octave -q

Where we can download DESHC

Anonymous's picture

Where we can download DESHC ?

Geek Guide
The DevOps Toolbox

Tools and Technologies for Scale and Reliability
by Linux Journal Editor Bill Childers

Get your free copy today

Sponsored by IBM

8 Signs You're Beyond Cron

Scheduling Crontabs With an Enterprise Scheduler
On Demand
Moderated by Linux Journal Contributor Mike Diehl

Sign up and watch now

Sponsored by Skybot