MD5 hashes are one-way, so you can't "decrypt" a password of which you only have the MD5 hash. Unless you do a brute force attack, and have a lot of patience (or luck).

Furthermore, encryption/decryption doesn't help. It doesn't help at all. If it's all "self-contained" (that is, there's no interaction with a source providing the password), the password will be visible for the EUID that runs the program. No matter how many times you encrypt. Because if you encrypt, you need to decrypt, and the steps to decrypt will be in the source. You've just transferred the need to keep the password a secret, to the need to keep the decryption key a secret....

There may be ways to make things more secure, but then you first have to determine who you are defending against. The casual shoulder surfer? Other, normal, users on the system? People with access to the network? Hackers/crackers? Professional industrial spionage? The FBI/CIA/NSA/MI5/MI6/Mossad/KGB?

Abigail

In reply to Re: Handling Passwords Securely by Abigail-II
in thread Handling Passwords Securely by cymon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.