Converting Java byte to Perl

Question

Have a program written in Java that compresses then encrypts using cipher openssl aes.

I am writing a program in Perl that will decrypt then uncompress.

I am having problems with decrypting part and believe it is related to Java byte conversion for IV.

Note: I do not know anything about Java language.

Java:

static byte[] IV = new byte[] {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};

Perl:

my $iv = pack('b128', 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);

I have tried above and a few other combinations, but does not seem to be correct IV.

Please tell me how to do the conversion correctly.

Answer 1

You can read about pack in the docs .

b corresponds to a bit string in the context of pack , which probably isn't what you want. There is an example in perlpacktut that looks like this:

$byte = pack( 'B8', '10001100' ); # start with MSB
$byte = pack( 'b8', '00110001' ); # start with LSB

You might be able to use c which corresponds to a signed char (8-bit) value .

my $iv = pack('c16', 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);
print unpack 'c16', $iv;

Which I think would be similar to this Java code:

import java.lang.Byte;
import java.util.Arrays;
public class ByteStuff{

     public static void main(String []args){

        byte[] IV = new byte[] {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
         System.out.println(Arrays.toString(IV));
     }
}