#!/usr/bin/perl
use strict;
use warnings;
use Digest::MD5 ('md5_base64');

sub my_crypt {
    my ($pass, $user)=@_;
    my $salt = md5_base64($user);
    return md5_base64($salt.$pass);
}

print "user> ";
chomp (my $user = <STDIN>);
print "pass> ";
chomp (my $pass = <STDIN>);
my @salt = ('a'..'z', 'A'..'Z');
my $passc = my_crypt($pass, $user);

open my $fh, '>>pass.pwd' or die $!;

print $fh "$user\t$passc\n";
close($fh);

# then i read it and check it like this:

print "user> ";
chomp ($user = <STDIN>);
print "pass> ";
chomp ($pass = <STDIN>);

open $fh, '<pass.pwd' or die $!;

my $matched;
while(<$fh>){
    next unless /^$user/;
    ($user, $passc) = split /\s+/, $_;
    if (my_crypt($pass, $user) eq $passc){
        print "Matched\n";
        $matched++;
        last;
    }
}

print "No Match\n" unless $matched;

__END__
>./passtest
user> random
pass> test12345678
user> random
pass> test12345678
Matched
>rm pass.pwd
>./passtest
user> random
pass> test12345678
user> random
pass> test1234567
No Match
>cat pass.pwd
random  6EtC2Kp14XloIR7y4KdOQw