I need to send an encrypted code to a web server where it will be decrypted with a java script. I have a script that creates the token and another that can decrypt it. The problem is when I send it to the java script, it throws an exception because of the padding. PKCS#5 pads with the number of bytes that should be truncated. So, if blocksize is 8, then "0A0B0C" will be padded with "05", resulting in "0A0B0C0505050505". If the final block is a full block of 8 bytes, then a whole block of "0808080808080808" is appended. In my script I can pad with nulls but how would I do PKCS#5? If someone could rewrite this (even using Crypt::CBC) and get the 32 character token with the correct padding, I would be forever grateful

In my haste to post the code, I didn't complete the scrubbing. I've made the corrections.

#!/usr/bin/perl

use Crypt::Rijndael;

my $key = "1A2B3C4D5E6FA1B2C3D4E5F61A2B3C4D";
$key = pack("H*",$key);

$crypt = Crypt::Rijndael->new( $key, Crypt::Rijndael::MODE_ECB() );

my $vers = 1;
my $rand = 1002247;
my $time = 1317072992;
my $empid = 123;
my $sum = 103;

$packed = pack( "CLLLC", $vers, $rand, $time, $empid, $sum );

my $token = $crypt->encrypt($packed^("\0"x16));
$token = unpack("H*",$token);

print "---------+---------+---------+--\n";
print $token,"\n";

exit;

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In reply to AES/ECB/PKCS#5 encryption by dbarstis

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