File Coverage

blib/lib/Crypt/CBCeasy.pm

Criterion	Covered	Total	%
statement	25	69	36.2
branch	2	30	6.6
condition	0	21	0.0
subroutine	8	15	53.3
pod	0	1	0.0
total	35	136	25.7

# easy en/decryption with DES/IDEA/Blowfish and some other ciphers
# Mike Blazer

package Crypt::CBCeasy;

use 5.003;
use Crypt::CBC;
use Carp;
use Symbol;

use strict;
no strict 'refs';
use vars qw($VERSION @DEFAULT_CIPHERS $LastCipher);

$VERSION = '0.24';
@DEFAULT_CIPHERS = qw/DES IDEA Blowfish/;


#--------------
sub useCBC {
#--------------
# $from - handler (r), filename or just plain or encrypted text
# $to   - handler (r), or filename. If '' or undef sub returns $to-string
  my ($key, $from, $to) = @_;
  my $sub               = (caller(1))[3]; # caller subroutine
  my ($algorithm, $op)  = $sub =~ /^(.*)::(.*)$/;
#print "$algorithm, $op\n";
  $LastCipher = $algorithm;

  my ($fhi, $fho, $fromFile, $INopened, $OUTopened,
      $buffer, $fromStr, $toStr, $cipher);

  croak "CBCeasy: source not defined\n"      unless defined $from;
  croak "CBCeasy: key not defined\n"         unless defined $key;
  croak "CBCeasy: I can do only `encipher' or `decipher'\n"
     unless $op && $op =~ /^(encipher|decipher)$/i;

  if ((UNIVERSAL::isa($from, 'GLOB') ||     # \*HANDLE
       UNIVERSAL::isa(\$from,'GLOB')        # *HANDLE
       ) &&  defined fileno $from
     ) {

     $fhi = $from;
     $fromFile = 1;

  } elsif (-e $from && -r _) {      # filename
     $fhi = gensym;
     $fromFile = 1;
     $INopened = 1;
     open ($fhi, $from) || croak "CBCeasy: file `$from' not found/readable\n";

  } elsif (-e $from && !-r _) {     # filename
     croak "CBCeasy: file `$from' not readable\n";

  } else { # stream itself in $from
  }

  $cipher = new Crypt::CBC($key, $algorithm);
  $cipher->start(lc $op);

  if ($fromFile) {

     binmode $fhi;
     # fails with too long chains
     while (read($fhi,$buffer,4096)) {
	$toStr .= $cipher->crypt($buffer);
     }
     $toStr .= $cipher->finish;

     close $fhi if $INopened;

  } else {
     # fails with too long chains
     while ($from) {
       $fromStr = substr($from, 0, 4096);
       substr($from, 0, 4096) = '';
       $toStr .= $cipher->crypt($fromStr);
     }
     $toStr .= $cipher->finish;
  }

  return $toStr unless $to;

  if ((UNIVERSAL::isa($to, 'GLOB') ||     # \*HANDLE
       UNIVERSAL::isa(\$to,'GLOB')        # *HANDLE
      ) &&  defined fileno $to
     ) {

     $fho = $to;

  } else {      # filename
     $fho = gensym;
     $OUTopened = 1;
     open ($fho, ">$to") || croak "CBCeasy: can't write file `$to'\n";

  }

  binmode $fho;
  print $fho $toStr;

  close $fho if $OUTopened;

}

#--------------
sub import {
  my $pkg = shift;

  for (@_ ? @_ : @DEFAULT_CIPHERS) {
     eval <<"E_O_P" unless defined *{"$_\::encipher"}{CODE};

	 sub $_\::encipher { useCBC(\@_) }
	 sub $_\::decipher { useCBC(\@_) }
E_O_P

  }
}

1;
__END__