Re: Java to perl conversion

To clarify a bit more of the situation

The encryption cipher from JAVA is out of my hands and generated by an API
I somehow need to match the same cipher in perl

JAVA CODE to generate the Cipher

String key = "just a bunch of text";
byte[] bytes = new byte[256];
byte[] kbytes = key.getBytes();
for (int i = 0; i < bytes.length; i++) {
   if (i < kbytes.length) {
     bytes[i] = kbytes[i];
   } else {
     bytes[i] = (byte) i;
   }
}
byte[] md5digest = md5DigestAsBytes(bytes);
try {
   theGeneratedKey = Twofish_Algorithm.makeKey(md5digest);
   blockSize = Twofish_Algorithm.blockSize();
   catch (java.security.InvalidKeyException ike) {
     throw new Exception(Exception.E_SECURITY, "Invalid security key '
+" + new String(md5digest) + "'", ike);
   }
[download]

the part that i need a bit help with:

String key = "just a bunch of text";
byte[] bytes = new byte[256];
byte[] kbytes = key.getBytes();
for (int i = 0; i < bytes.length; i++) {
   if (i < kbytes.length) {
     bytes[i] = kbytes[i];
   } else {
     bytes[i] = (byte) i;
   }
}
byte[] md5digest = md5DigestAsBytes(bytes);
[download]

The rest is quite obvious
I am lacking the experience with java to replicate the code and test it against a perl version
Question should read:
I need to match the exact same cipher in Perl
to be able to utilize Crypt::Twofish and decrypt the data. How can I do this in Perl

This is my first post here.

Comment on Re: Java to perl conversion Select or Download Code

Replies are listed 'Best First'.
Re^2: Java to perl conversion (Updated) by BrowserUk (Patriarch) on May 31, 2013 at 10:37 UTC
the part that i need a bit help with: Looking again, I'm wrong! The string/array isn't null padded, but rather padded with bytes equivalent to their position. ~~This does exactly that.~~ But you will need to understand that Java's byte arrays and Perl's scalars (when they contain strings) are effectively equivalent. So, use: `my $string = "just a bunch of text"; $string .= pack 'C*', length( $string ) .. 255; my $md5 = md5( $string );` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]

Replies are listed 'Best First'.

Re^2: Java to perl conversion (Updated)
by BrowserUk (Patriarch) on May 31, 2013 at 10:37 UTC

the part that i need a bit help with:

Looking again, I'm wrong! The string/array isn't null padded, but rather padded with bytes equivalent to their position.

~~This does exactly that.~~

But you will need to understand that Java's byte arrays and Perl's scalars (when they contain strings) are effectively equivalent.

So, use:

my $string = "just a bunch of text";
$string .=  pack 'C*', length( $string ) .. 255;
my $md5 = md5( $string );
[download]

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

[reply]
[d/l]