Digest::MD5 doesn't take an array; it takes a string.

If simply passing your strings to Digest::MD5::md5() does not produce the same 16-byte value that the Java code is producing, it will be because the Java code is digesting the entire 256-byte packet including the trailing nulls.

Therefore the solution is to pad the string to 256-bytes with nulls before generating the md5:

my $string = ...; # get the string from wherever
$string = pack 'a256', $string; ## Will null pad to the specified leng
+th
my $md5 = md5( $string );
... do the twofish stuff.
[download]

That doesn't deal with strings that start out greater than 256, but neither does the Java code.

It will also not correctly deal with strings where char != byte.

If that is a requirement, the simplest solution will be to turn off the utf flag before the pack, but there is undoubtedly a (suite of) modules that will do the same thing.

Have a look at Digest::MD5 and you'll see that it has an add method and you won't have to bother with byte arrays.

So,I think you should be able to do something like this, untested code

   my $md5 = Digest::MD5->new;
   $md5->add($key);
   $md5->add( chr($_) ) for length($key) .. 255;
   my $tfkey = $md5->digest();
[download]

If that doesn't work then you'll have to play around with pack/unpack.

Have you read perlintro? Use Crypt::Twofish?

The Crypt::Twofish is not the issue. the issue is to generate the exact same md5 digest. That one is build up from the bytes of the string

java:

String key = "1234567890";

perl:

my $key = "1234567890";
[download]

so I need to be able to create the exact same 256 byte array.

java:

byte[] bytes = new byte[256];
[download]

getting the bytes of the string is also an issue

java:
byte[] kbytes = key.getBytes();
[download]

the loop in the code is also quite simple.
So what I really need: perl code to
1. Generate a 256 byte array 2. perl code to convert the characters from stringdata to byte. Thanks

Most likely, you will want to use either an array, and put the string there (split), or just use a string and substr to access the characters within the string.

Arrays and strings are not sized in Perl.

... 1. Generate a 256 byte array 2. perl code to convert the characters from stringdata to byte. Thanks

Um, you don't need to turn a string into an array to generate an md5sum, see Digest::MD5

You also don't need an array for Crypt::Twofish

perlintro explains about perl variable types, perldata explains further, then binmode and perlunitut

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]

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 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.