You might want to look at this Sockets-file-upload-w-EasyTCP

It has a port password and optional encryption of files. The Net::EasyTCP module has been improved since I wrote this script, so you can do:

my @nocrypt = qw(Crypt::RSA); #too slow, but more secure 

my $server = new Net::EasyTCP(
    host  =>  "$host",
    mode  =>  "server",
    port  =>   "$port",
#    donotencrypt => 1, 
    donotencryptwith => \@nocrypt,
    password => "$portpassword",
    )
       || die "ERROR CREATING SERVER: $@\n";
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