Re: encryption
On 04/20/18 12:38, Brian wrote:
T have a script. It contains an important password.
I have encrypted the script with
scrypt dec -t 10 /usr/local/bin/myscript
Looking at:
http://manpages.org/scrypt
That command decrypts /usr/local/bin/myscript (and I don't know if the
-t option is valid for decryption).
I can, of course, decrypt it with
scrypt dec /usr/local/bin/myscript
Assuming /usr/local/bin/myscript is ciphertext, that command will print
the script on STDOUT.
As scrypt is going to prompt you for a passphrase anyway, why don't you
leave the script unencrypted and revise it to prompt for the "important
password"?
and then execute the script.
How are you executing a script printed on STDOUT? A pipeline?
The two last steps have been combined into
DECRYPT=$(scrypt dec /usr/local/bin/myscript) && eval "$DECRYPT"
Should I have any more concerns with this command than I have with the
two-step process?
If the script is too big to fit in an environment variable, that would
be a problem.
Assuming the script fits into an environment variable, evaluating that
variable in double-quoted context requires deep understanding of both
your shell and the script (especially if the script is written for a
different shell, and potentially a different version of the same shell).
If you're intent upon doing it this way, be sure to test thoroughly.
A pipeline would be more conventional-- decrypt the ciphertext and pipe
the script to the appropriate interpreter. Here is an example using
Perl and the ccrypt tools:
2018-04-20 16:59:50 dpchrist@vstretch ~/sandbox/ccrypt
$ ll secret-script.pl
-rwxr-xr-x 1 dpchrist dpchrist 66 2018/04/20 16:58:19 secret-script.pl*
2018-04-20 17:00:02 dpchrist@vstretch ~/sandbox/ccrypt
$ cat secret-script.pl
#!/usr/bin/env perl
print "The important password is 'secret'\n";
2018-04-20 17:00:08 dpchrist@vstretch ~/sandbox/ccrypt
$ ./secret-script.pl
The important password is 'secret'
2018-04-20 17:00:14 dpchrist@vstretch ~/sandbox/ccrypt
$ ccencrypt --key foo secret-script.pl
2018-04-20 17:00:26 dpchrist@vstretch ~/sandbox/ccrypt
$ ll secret-script.pl.cpt
-rwxr-xr-x 1 dpchrist dpchrist 98 2018/04/20 16:58:19 secret-script.pl.cpt*
2018-04-20 17:00:30 dpchrist@vstretch ~/sandbox/ccrypt
$ ll decrypt-run-secret.sh
-rwxr-xr-x 1 dpchrist dpchrist 86 2018/04/20 16:57:27 decrypt-run-secret.sh*
2018-04-20 17:00:40 dpchrist@vstretch ~/sandbox/ccrypt
$ cat decrypt-run-secret.sh
#!/usr/bin/env sh
echo "The decryption key is 'foo'"
ccat secret-script.pl.cpt | perl
2018-04-20 17:00:51 dpchrist@vstretch ~/sandbox/ccrypt
$ ./decrypt-run-secret.sh
The decryption key is 'foo'
Enter decryption key:
The important password is 'secret'
David
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