I don't know Sun's crypt program, and I don't know if someone made a perl version of it. My suggestion is to invoke the program from your perl script when you need it?
You can use system: here is an example from perlfunc man page:

@args = ("command", "arg1", "arg2");
system(@args) == 0
     or die "system @args failed: $?"
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Instead if you need to catch the crypt program output you can use a pipe open

$param1 = "some value";
$param2 = "some other value";
open (CRYPT, "crypt -$param1 -$param2 |") or die "error: $!";
while (<CRYPT>) {
    print; #here you can make any manipulation you need with the progr
+am output
}
close (CRYPT);
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Hope this helps.
marcos