decrypting the /etc/passwd file

[vickey_20]

Hey I want to find out the passwd of a user by decrypting it. Is there a software available or some method of doing it???

[elija]

If the password has been forgotten you will have to reset it as far as I know

[vickey_20]

is it possible to decrypt the password in the /etc/shadow file if the cryptic line is obtained

[Freston]

No. Although a clever hacker might argue otherwise, because I believe it is not entirely impossible theoretically. Still, the answer to your question is 'no, tis not possible'.

When you have root, you can set and reset passwords though.

[Krendoshazin]

MD5 hashes are one way, that means they're not designed to be decrypted they're merely used for comparison. It is theoretically possible to crack MD5 with a tool that MD5 hashes a given word and compares it to the MD5 sum. This, however, is not really cracking but brute-forcing; with a decent password (no less than 8 characters, not dictionary based) your chances of brute-forcing it are slim to none.
A good password is the root of all security.

[bigtomrodney]

As I understand it, the shadow file on modern systems can be "decrypted" using rainbow tables. This is where the hashes are prepared in advance by running as many words as possible through password encyrption and only later comparing the new encrypted strings with those in /etc/shadow.

[elija]

That doesn't sound like a good idea. Very insecure?

[bigtomrodney]

I think MD5 and SHA1 have both been proved to have vulnerabilities. They're really only useful for checksums on distributed media, no use for actual encryption from what I'm told.

Rainbow tables themselves are now quite common. I think 0phtcrack uses them.

Rainbow table - Wikipedia, the free encyclopedia

[vickey_20]

is there any passwd cracking utility for linux like ophtcrack??

[elija]

I think MD5 and SHA1 have both been proved to have vulnerabilities. They're really only useful for checksums on distributed media, no use for actual encryption from what I'm told.

Rainbow tables themselves are now quite common. I think 0phtcrack uses them.

Rainbow table - Wikipedia, the free encyclopedia

Yikes! I really must keep up!