SSL Cert Scan - TLS Deprication

#!/usr/bin/env perl
# requires system path to contain links to dig, sslscan and nmap.
# autoflush the output by turning buffering off
$|++;

use strict;
use warnings;
use Switch;
use Data::Dumper;

my $debug = 0; # 1 outputs all to screen, 0 outputs to file
my $output = 2; # (1 - all, 2 - error certs only, 3 - valid certs only) valid = certs meeting algo and keysize requirements
my $date = `date +%Y-%m-%d_%H%M%S`;
chomp($date);
my $outfile = "/tmp/sslscan-$date.csv";
if (! $debug) { print "Result file: $outfile\n"; }
my $timeout = 5; # command execution timeout

my @networks = ( # subnets to scan
                 '10.10.1.0/24',
               );

my @ports = ( # ports to scan for SSL certs
              '443',
              '8443',
            );

my @goodalgos = (
                  'sha256WithRSAEncryption',
                );
my %goodalgo = map { $_ => 0 } @goodalgos;

my $minkeysize = 2048; # minimum valid key length

my @ignoredips = ( # ips to ignore
                  );
my %ignored = map { $_ => 0 } @ignoredips;

my @sslhosts;

foreach my $network (@networks){
  if ($debug) { print "Scanning subnet $network\n"; }
  foreach my $port (@ports){
    my @nmapout = `nmap -p$port -Pn -oG - $network`;
    foreach my $line (@nmapout){
      chomp ($line);
      if ($line =~ /open/){
        my (undef, $ip, undef) = split (/ /, $line, 3);
        if (! exists($ignored{$ip})){
          push @sslhosts, "$ip:$port";
        }
      }
    }
  }
}
#print @sslhosts;
my %certs = ();
foreach my $host (@sslhosts){
  if ($debug) { print "Scaning Host: $host\n"; }
  my @sslscan = `timeout $timeout sslscan --no-failed $host`;
  my ($cn, $algo, $keysize, $start, $end, $issuer) = "";
  my ($ip, $port) = split (/:/, $host, 2);
#  if ($debug) { print "IP: $ip port: $port\n"; }
  $certs{$ip}{$port} = ();
  foreach my $line (@sslscan){
    chomp ($line);
    switch ($line){
      case /Public-Key:/ {
        $line =~ /(\d+)/;
        $keysize = $1;
        if ($debug) { print "Key: $keysize\n"; }
        $certs{$ip}{$port}{'keysize'} = $keysize;
      }
      case /Subject:/ {
        $line =~ /CN=(.*)/;
        $cn = $1;
        if (length $cn){
        }else{
          $cn = `timeout $timeout dig +short -x $ip`;
          chomp($cn);
          chop($cn);
        }
        if ($debug) { print "CN: $cn\n"; }
        $certs{$ip}{$port}{'cn'} = $cn;
      }
      case /Signature Algorithm:/ {
        $line =~ /Signature Algorithm:\W(.*)/;
        $algo = $1;
        if ($debug) { print "Algorithm: $algo\n"; }
        $certs{$ip}{$port}{'algo'} = $algo;
      }
      case /Issuer:/ {
        $line =~ /Issuer:\W(.*)/;
        $issuer = $1;
        if ($debug) { print "Issuer: $issuer\n"; }
        $certs{$ip}{$port}{'issuer'} = $issuer;
      }
      case /Not valid before:/ {
        $line =~ /Not valid before:\s(\w+\s+\d+).*(\d{4})/;
        my $date = "$1 $2";
        if ($debug) { print "Start Date: $date\n"; }
        $certs{$ip}{$port}{'start'} = $date;
      }
      case /Not valid after:/ {
        $line =~ /Not valid after:\s(\w+\s+\d+).*(\d{4})/;
        my $date = "$1 $2";
        if ($debug) { print "End Date: $date\n"; }
        $certs{$ip}{$port}{'end'} = $date;
      }
    }
  }
}

if ($debug) { print "Completed Scan\n"; }
if ($debug) { print Dumper %certs; }

if ($debug) { print "^IP^Port^Name^Keysize^Algorithm^Issuer^Start^End^Life^\n"; }
else {
  open(FH, '>', $outfile);
  print FH "^IP^Port^Name^Keysize^Algorithm^Issuer^Start^End^Life^\n";
}
foreach my $ip (keys %certs){
  foreach my $port (keys %{$certs{$ip}}){
    if (defined $certs{$ip}{$port}){
      my $line = "";
      switch ($output) {
        case 1 { # all certs
          $line = "|$ip|$port|$certs{$ip}{$port}{'cn'}|$certs{$ip}{$port}{'keysize'}|$certs{$ip}{$port}{'algo'}|";
          $line = $line."$certs{$ip}{$port}{'issuer'}|$certs{$ip}{$port}{'start'}|$certs{$ip}{$port}{'end'}|";
        }
        case 2 { # error certs
          if ($certs{$ip}{$port}{'keysize'} < $minkeysize || ! exists $goodalgo{$certs{$ip}{$port}{'algo'}}){
            $line = "|$ip|$port|$certs{$ip}{$port}{'cn'}|$certs{$ip}{$port}{'keysize'}|$certs{$ip}{$port}{'algo'}|";
            $line = $line."$certs{$ip}{$port}{'issuer'}|$certs{$ip}{$port}{'start'}|$certs{$ip}{$port}{'end'}|";
          }
        }
        case 3 { # valid certs
          if ($certs{$ip}{$port}{'keysize'} >= $minkeysize && exists $goodalgo{$certs{$ip}{$port}{'algo'}}){
            $line = "|$ip|$port|$certs{$ip}{$port}{'cn'}|$certs{$ip}{$port}{'keysize'}|$certs{$ip}{$port}{'algo'}|";
            $line = $line."$certs{$ip}{$port}{'issuer'}|$certs{$ip}{$port}{'start'}|$certs{$ip}{$port}{'end'}|";
          }
        }
      }
      if (length $line){
        if ($debug) { print "$line\n"; }
        else { print FH "$line\n"; }
      }
    }
  }
}
if (! $debug){
  close(FH);
}