Greetings Monks,

Hopefully someone with a bit more robe ruffling experience than I can weigh in here...

I'm trying to match encrypted passwords in /etc/shadow (edit: actually stored in a DB, encrypted passwords only) with those programatically generated using Crypt::Password, but I must be missing something (eg, what salt is used in Linux when the password command is used to set/change the password. edit: I started scanning the passwd(1) source to get a clue, but started to feel nauseous either from the code, or from christmas chow, not sure which)

eg, given the following /etc/shadow entry (user 'bob', password 'abc'): 

bob:$1$Wl2RANfv$M9PjezS//sUMDRnhhO5vR1:16065::::::

[download]

I now to try to replicate that password using this code ($1 implies MD5):

use Crypt::Password;

print password("abc", "bo", "md5") . "\n";

[download]

Which yields:

$1$bo$e/EvseYfe8hj3LasblgjX.

[download]

...Obviously not a match

Am I on the right track here? Is this a case of not using the same salt string?

FYI, I need this to authenticate users which are being migrated from an /old/ server to a new one, and we only have the encrypted passwords, so I need to authenticate them with new proposed systems...

I'd appreciate pointers in what I'm doing wrong here. Thanks a mill.

---------------------------

Documenting answer: Abbot ambrus on chatterbox says pass the entire encrypted string as salt (lib will know how to parse it): 

use Crypt::Password;

print password("abc", '$1$Wl2RANfv$M9PjezS//sUMDRnhhO5vR1', "md5") . "
+\n";

[download]
thanks!!

In reply to Matching encrypted passwords by perlmoi

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