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>"crypt" function in Linux</H3>
<p><strong>From Ben Okopnik
</strong></p>
<p align="right"><strong>Answered By
<p></strong></p>
<BLOCKQUOTE>
Just a little while ago, I needed to use the "crypt" program, so
well-known in other Unices, to encode a text file (for those of you
unfamiliar with it, it encrypts the contents of a file using a password
that you supply. A fairly useful little utility when you want just a bit
of added security on a publicly-readable file.) Imagine my surprise when
I found that Linux does not have one! Once again, it's Perl to the rescue.
</BLOCKQUOTE>
<BLOCKQUOTE>
This version follows the syntax of the original "crypt", although
I'm certain that the algorithm is different. The encryption and the
decryption are symmetric, meaning that the same syntax is used for both
(with the obvious exception of the relevant filenames):
</BLOCKQUOTE>
<blockquote><code><font color="#000033"><br># This encrypts the contents of "mysecret.txt" using "iAMw0tIam" as the
<br># password and saves the results to "mysecret.encrypted".
<br>crypt iAMw0tIam < mysecret.txt > mysecret.encrypted
<br>
<br># This prints out the decrypted contents of "mysecret.encrypted" to the
<br># screen.
<br>crypt iAMw0tIam < mysecret.encrypted
<br>
<br># This decrypts the contents of "mysecret.encrypted" and writes the results
<br># to "mysecret.decrypted".
<br>crypt iAMw0tIam < mysecret.encrypted > mysecret.decrypted
</font></code></blockquote>
<BLOCKQUOTE>
Long passwords are preferable to short ones for better security;
"crypt" accepts them without a problem, provided that any password
containing spaces or other "weird characters" is quoted (preferably
in single quotes).
</BLOCKQUOTE>
<blockquote><code><font color="#000033"><br> crypt 'Praeterea, censeo Carthaginem esse delendam.' < file > file.enc
</font></code></blockquote>
<BLOCKQUOTE>
As always, bug reports, comments, and piles of diamonds are welcome.
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<p align="center">See attached <tt><a href="../misc/tag/crypt.perl.txt">crypt.perl.txt</a></tt></p>
<BLOCKQUOTE>
Ben Okopnik
</BLOCKQUOTE>
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