Thread: How to use GNU Crypto LIbrary in Matlab via Java Interface

Hi All,

I find it very difficult to do the encryption in matlab using GNU Crypto library



One example given in a book Using Javax.crypto

function e = encrypt(t, key)
%ENCRYPT: e = encrypt(t, key)
% Encrypt the plaintext string t into
% the encrypted byte array e using a key
% from getkey.
import javax.crypto.*
cipher = Cipher.getInstance('DESede') ;
cipher.init(Cipher.ENCRYPT_MODE, key) ;
e = cipher.doFinal(int8(t))' ;

function t = decrypt(e, key)
%DECRYPT: t = decrypt(e, key)
% Decrypt the encrypted byte array e
% into to plaintext string t using a key
% from getkey.
import javax.crypto.*
cipher = Cipher.getInstance('DESede') ;
cipher.init(Cipher.DECRYPT_MODE, key) ;
t = char(cipher.doFinal(e))' ;

function key = getkey(password)
%GETKEY: key = getkey(password)
% Converts a string into a key for use
% in the encrypt and decrypt functions.
% Uses triple DES.
import javax.crypto.spec.*
b = int8(password) ;
n = length(b) ;
b((n+1):24) = 0 ;
b = b(1:24) ;
key = SecretKeySpec(b, 'DESede') ;

But i want to use

Anubis
gnu.crypto.cipher.Anubis

h**p://www.gnu.org/software/gnu-crypto/manual/api/gnu/crypto/cipher/Anubis.html

is it possible to do the same way as it is given in the javax.crypto case ?

I tried this ,but nothing happens

%   public void encrypt(byte[] in,
%                     int i,
%                     byte[] out,
%                     int j,
%                     java.lang.Object k,
%                     int bs)
% 
% 
% 
%     Encrypts exactly one block of plaintext.
% 
%     Parameters:
%         in - the plaintext.
%         i - index of in from which to start considering data.
%         out - the ciphertext.
%         j - index of out from which to store the result.
%         k - the session key to use.
%         bs - the block size to use.
%
%
%
% %public java.lang.Object makeKey(byte[] uk,
%                                 int bs)
%    throws java.security.InvalidKeyException
 
 
clear all
clc
 
J1=javaObject('gnu.crypto.cipher.Anubis')
 
in =uint8([zeros(1,16)]) ;
out =uint8([zeros(1,16)]) ;
 
 
bs=16;
 
uk=logical([zeros(1,15),1]); 
 
 
k=J1.makeKey(uk,bs);
 
J1.encrypt(in,0,out,0,k,16)

class Anubis

Constructor Summary
Anubis()
Trivial 0-arguments constructor.

Method Summary
java.util.Iterator blockSizes()
Returns an Iterator over the supported block sizes.
java.lang.Object clone()
Returns a clone of this instance.
void decrypt(byte[] in, int i, byte[] out, int j, java.lang.Object k, int bs)
Decrypts exactly one block of ciphertext.
void encrypt(byte[] in, int i, byte[] out, int j, java.lang.Object k, int bs)
Encrypts exactly one block of plaintext.
java.util.Iterator keySizes()
Returns an Iterator over the supported key sizes.
java.lang.Object makeKey(byte[] uk, int bs)
Expands a user-supplied key material into a session key for a designated block size.
boolean selfTest()
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).