> I am devoloping an application that has to use crypted password for some
> and I wonder If there is some library that crypt and decrypt password.
You'll not find a function to decrypt passwords, because crypt() is
to work one way only. The usual check if a password is valid or not is to
crypt the password again, and check if you get the same (crypted) result.
If so, the password was valid, if not, the password was invalid.