On Nov 18, 2010, at 5:52 AM, Julian Fagir wrote: > The straight-forward way would be to write this script, have all input parsed > by read and then let the script act according to this input (let's assume > that these tools are secure, it's just cp'ing and writing to > non-sensitive files. > > Are there possibilities to escape from such a script down to a prompt?
Yes; consider using something like: trap "" 2 3 18 ...prevent them from using control-C, control-Z, control-\ to play games with the script. > All in all, this is a more general question I have for quite a time: Can you > use shell-scripts for security-relevant environments? Yes, but you really shouldn't trust them any farther than you would trust a user with an interactive shell. It's just too easy to exploit $IFS, invoke command line utilities that provide shell escapes, etc. Python or C is likely to be more securable, but getting it right is trickier than it may appear. Start with never trusting user-supplied inputs, always validate against a whitelist of what is trusted rather than trying to blacklist bad stuff. Regards, -- -Chuck _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
