topic Re: Shell Compiler in Operating System - HP-UX

Shell Compiler

Mark Philip L. Castro — Fri, 04 Jun 2004 01:59:39 GMT

Is there such thing as a posix shell compiler or any thing software that can make your executable posix shell script unreadable but executable?

Re: Shell Compiler

John Carr_2 — Fri, 04 Jun 2004 02:40:38 GMT

Hi

not sure exactly what you are trying to achieve but try this

cp /usr/bin/sh ~
cd ~
chmod 111 ./sh

ls -l ./sh

./sh

you have an executable shell with no read permissions

John.

Re: Shell Compiler

Mark Philip L. Castro — Fri, 04 Jun 2004 02:47:39 GMT

Rephrasing my question, is there any way I can hide the contents of a posix shell SCRIPT so as to make the file executable but not readable?

Re: Shell Compiler

Eric Antunes — Fri, 04 Jun 2004 02:53:10 GMT

Try the following:

chmod ugo-rw <script>.sh

Re: Shell Compiler

John Carr_2 — Fri, 04 Jun 2004 02:54:28 GMT

Hi

I do not think it is possible to compile a shell script to achieve this. You can however compile perl which will hide the code.

John.

Re: Shell Compiler

John Carr_2 — Fri, 04 Jun 2004 02:58:10 GMT

I think Antunes is mistaken the script will not execute without read permission.

carrjo% chmod 111 test
carrjo% ls -la
total 418
drwxr-xr-x 2 carrjo root 96 Jun 4 08:51 .
drwxr-xr-x 23 root root 1024 May 27 13:56 ..
-rw------- 1 carrjo 1494 4 Jun 4 08:37 .sh_history
-rw-r--r-- 1 carrjo 1494 0 Mar 17 14:47 foo
---x--x--x 1 carrjo 1494 209136 Jun 4 08:36 ksh
---x--x--x 1 carrjo 1494 53 Jun 4 08:51 test
---------- 1 carrjo 1494 29 Mar 17 14:27 testfile
carrjo% ./test
./test: ./test: cannot open
carrjo% chmod 555 test
carrjo% ls -la
total 418
drwxr-xr-x 2 carrjo root 96 Jun 4 08:51 .
drwxr-xr-x 23 root root 1024 May 27 13:56 ..
-rw------- 1 carrjo 1494 4 Jun 4 08:37 .sh_history
-rw-r--r-- 1 carrjo 1494 0 Mar 17 14:47 foo
---x--x--x 1 carrjo 1494 209136 Jun 4 08:36 ksh
-r-xr-xr-x 1 carrjo 1494 53 Jun 4 08:51 test
---------- 1 carrjo 1494 29 Mar 17 14:27 testfile
carrjo% ./test
hello world
***********
ss1025:carrjo%

Re: Shell Compiler

Eric Antunes — Fri, 04 Jun 2004 03:03:32 GMT

Your're wright John, if I canÂ´t read it, I canÂ´t execut

Re: Shell Compiler

Steve Lewis — Fri, 04 Jun 2004 03:14:16 GMT

Look at this shell compiler:

http://www.comeaucomputing.com/faqs/ccshlit.html

These things have been around for a while.

Re: Shell Compiler

Mark Philip L. Castro — Fri, 04 Jun 2004 03:39:35 GMT

where can I download or acquire this compiler?

Re: Shell Compiler

John Carr_2 — Fri, 04 Jun 2004 04:08:35 GMT

Mark

you will have problems if you use the ccsh compiler Steve has pointed you to it is NOT the posix shell you have mentioned. You may be able to change your scripts to be the bourne shell then compile the script of course.

John.

Re: Shell Compiler

Sanjay Kumar Suri — Fri, 04 Jun 2004 04:29:10 GMT

You can do this by writing/compiling a small c program on the lines below:

#file1.c
main()
{
system("shell_script");
}

cc file1.c -o file1

Now file1 is executable and the script file shell_script can be hidden.

sks

Re: Shell Compiler

Mark Grant — Fri, 04 Jun 2004 04:34:27 GMT

I'll second that. Many people trust shell compilers but I wouldn't personally.

And you definately can't execute anything without read access.

There is one possiblity that comes to mind and that is to compress your scripts or even encrypt them but have a C program that you use as a decrypter/runner. Users have to use your C program to run the script.

I would ask why you need to do this. If it's a script that contains passwords or such like, there is nearly always a better way to achieve it. If it contains other sensitive information, just encrypt the parts of the code that are sensitive and get the script itself to decrypt that and use "eval" or some thing to run that portion of code.