I commented the 2 lines of $cipher. First , i used in Crypt::CBC and the next time i used Crypt::Rijndael. Both, didn't work fine.

That does not answer my question.

There are examples in Crypt::CBC synopsis, including an example of encrypting a "large" file, such as your multimedia file might be. Have you tried using Crypt::CBC as suggested there?

#!/usr/bin/perl
use warnings;
use strict;
use Crypt::Rijndael;

# keys must be 128, 192 or 256 "bits" long, 

# 8 bits in a letter, so 8 x 16 = 128
#my $key = 'abcdefgghjkloiuy'; #128 bits or 8 x 16
my $key = 'abcdefgghjkloiuyabcdefgghjkloiuy'; #256 bits or 8 x 32
print "key->$key\n";

my $plaintext= "adrqwqqqqqqqqqqqqqqqqqqqqqqwrxcq4gfq3g2q45g2q43g5";
print "plaintext->$plaintext\n";
my $plaintext16= get16($plaintext);
print "plaintext16->$plaintext16\n";


my $cbc = new Crypt::Rijndael $key, Crypt::Rijndael::MODE_CBC;
my $crypted = $cbc->encrypt($plaintext16);
print 'crypted->',"$crypted\n"; #keep encrypted string in different pr
+int string
                                #to avoid character corruption of prec
+eding string


my $cbc1 = new Crypt::Rijndael $key, Crypt::Rijndael::MODE_CBC;
my $decrypted = $cbc1->decrypt($crypted);
print "decrypted->$decrypted\n";

#this sub makes all data blocksize of 16 bytes.
sub get16 {
    my $data = shift;
     return $data . "\0" x ( 16 - length($data)%16 );
      }
      
exit;

#You can also use this to get data that is in a multiple of 16 bytes:
# this requires $username < 16 bytes and prefix packs with spaces
#    sprintf '%16s', $username;
#or you can xor it
# $filecrypted = $cipher->encrypt($file^("\0"x16));

#To strip any padding after decryption:
#my $plaintext = $cipher->decrypt($secret_stuff);
#   $plaintext =~ s/^\0+//;  
# remove leading null bytes, use \s (not \0) for spaces
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If you used Crypt::CBC,

• You wouldn't have to pad the file.
• You wouldn't have to make the key exactly the right size. What you pass is actually a passphrase from which a key of the right length is created.

By the way, your padding method is buggy. It will trim trailing NUL bytes in the data. Crypt::CBC uses a method that allows perfect recovery of the original.

Dear Monks,

I completely changed my script , using some examples mentioned used in Crypt::CBC

I believe, this code is working fine for me. But, just wanted to get the confirmation from you guys.

my $start=time();

use Crypt::CBC;
use strict vars;
use strict;
use warnings;

my $key="abcdefgghjkloiuy";

my $cipher = Crypt::CBC->new(-key    =>  $key,
                 -cipher => 'Rijndael',
                 -salt   => 1,
                ) || die "Couldn't create CBC object";
                
open(F,"Robo.mp4");

$cipher->start('encrypting');
  while (read(F,my $buffer,1024)) 
 {
    $cipher->crypt($buffer);
 }
 
 $cipher->finish;
my $end=time();

print "\n".$end-$start;
[download]

IF the code is completely correct, can someone suggest a better way to calculate the time for execution, which also shows the milliseconds too..