Base32 encoding/decoding RFC-3548

base32.pl

#!/usr/bin/perl -wT
# https://gist.github.com/ggrandes/df7151b9e2fca02da93acf44bedf7b43
use strict;
my $op = ($ARGV[0] || "");
my $text = ($ARGV[1] || "");
if (length($text) < 1) {
  print_usage();
} elsif (($op eq "-e") || ($op eq "--encode")) {
  print encode_rfc3548($text), "\n";
} elsif (($op eq "-d") || ($op eq "--decode")) {
  print decode_rfc3548($text), "\n";
} else {
  print_usage();
}

sub print_usage {
  print "$0 <-e|-d> <input>", "\n";
  exit 1;
}

sub encode_rfc3548 {
  my ($l, $e);
  $_ = unpack('B*', shift);
  s|(.....)|000$1|g;
  $l = length;
  if ($l & 7) {
    $e = substr($_, $l & ~7);
    $_ = substr($_, 0, $l & ~7);
    $_ .= ("000$e" . '0' x (5 - length $e));
  }
  $_ = pack('B*', $_);
  tr|\0-\37|A-Z2-7|;
  $_;
}

sub decode_rfc3548 {
  my ($l);
  $_ = shift;
  tr|A-Z2-7|\0-\37|;
  $_ = unpack('B*', $_);
  s|000(.....)|$1|g;
  $l = length;
  $_ = substr($_, 0, $l & ~7) if ($l & 7);
  $_ = pack('B*', $_);
  $_;
}