encryption is possible??

Shell Programming and Scripting
1

NEED expertise help for this topic!!!

Question 1: Is encryption possible for the shell scriping programing? shadow the scriping file, do think is impossible...

Question2: built a simple program with the simplicity function that allow user change settings by enter corret name and password combination, how to prevent the password not being seen by others just open up the scriping file?

Question 3: is possible to retrieval data from a encryped file? if can, how?

any comment are all welcome, Thanks in advance!!!

trynew

2

You can use encryption in a script but what are you using to write this in? If you are looking to do something with the password and/or shadow file, using Perl may be the way to go (at least for the call to the password/shadow file).

Unsure what you mean by "shadow the scripting file".

Question 2: What are you using - is this a web interface? Or just a script that normal users can run to change something (what?).

To prevent password from being seen:
from a web page: set input type to password
<input type="password" name="newpass" size=15>
For a terminal: stty -echo turns off echo, stty echo turns it back on. Check the man page for stty.

Q3: Yes, if you encrypt a file you can still retrieve data but you have to unencrypt it in the case of pgp. If you are talking about retrieve what a password is - not exactly. You can find out if a unencrypted password matches with the following - but you don't really unencrypt the password - you compare by encrypting.

Perl script to check a password - supply userid and password

#!/u/bin/perl
#
# Grab the user's old password from /etc/shadow and compare to sent
# old password from web page - send back error if not the same
#

$user = "$ARGV[0]";
$oldpass = "$ARGV[1]";
$datenow = "`date '+%h %d %T'`";
#
$userinfo = `/usr/bin/grep $user /etc/shadow`;
($user1, $passwd1, $passextra) = split(/:/, $userinfo, 3);
$salt = substr($passwd1,0,2);
#
if (crypt($oldpass, $salt) ne $passwd1) {
die "Not correct password";
}

3

Encrypt a shell scripting file, so nobody can see the context of file, but the scripting file still executable, anyway to do that?

4

http://www.datsi.fi.upm.es/~frosal/