I'm studying a migration from an old LDAP to a new database. Today I just found that the passwords are all saved as {crypt} passwords and the new system does not support that.
Is it possible to decode the {crypt} passwords (in PERL if possible) ?
No, crypt implements a one way hash.
However, you have the hash values and (hopefully) the salt. Whenever a user submits a password, it's encrypted with the same salt, and if the hashes match, the user is authenticated.
In general, it's a very bad practice to have human readable passwords, but you don't need to read a raw input password to authenticate a user.