GenSessionKeyFromEcdhKey.java

Example of generating a session key from elliptical keys (ECDH).

See Note on examples.

package doxy.examples;
 
import java.util.Arrays;
 
import com.dinamonetworks.Dinamo;
 
import br.com.trueaccess.TacException;
import br.com.trueaccess.TacNDJavaLib;
 
public class GenSessionKeyFromEcdhKey {
    private static String strAddr   = "127.0.0.1";
    private static String strUsrId  = "master";
    private static String strPwd    = "12345678";
    private static String strLocalKey   = "test_local_key";
    private static String strPeerKey    = "test_peer_key";
    private static String strSessionKey = "test_session_key";
 
    public static void main(String[] args) {
 
        Dinamo api = new Dinamo();
 
        try {
 
            System.out.println("--> Login HSM and create 2 Brainpool keys");
            api.openSession(strAddr, strUsrId, strPwd);
            api.createKey(strLocalKey, TacNDJavaLib.ALG_ECC_BRAINPOOL_P512T1);
            api.createKey(strPeerKey, TacNDJavaLib.ALG_ECC_BRAINPOOL_P512T1);
 
            System.out.println("--> Extract public part from local key");
            byte[] pbPeerPubKey = api.exportKey(strPeerKey, TacNDJavaLib.PUBLICKEY_BLOB);
 
            System.out.println("--> Construct a session key");
            byte[] pbSharedSecret = api.genEcdhKey( TacNDJavaLib.DN_GEN_KEY_KDF_RAW_SECRET,
                                                    strLocalKey,
                                                    pbPeerPubKey );
 
            /*
             * The shared secret is used directly in this example, only for educational purposes!!
             * We strongly advise to use KDF(Key Derivation Function) before importing the key.
             * */
            api.importKey(  strSessionKey,
                            TacNDJavaLib.PLAINTEXTKEY_BLOB,
                            TacNDJavaLib.ALG_AES_256,
                            TacNDJavaLib.EXPORTABLE_KEY,
                            pbSharedSecret,
                            TacNDJavaLib.ALG_AES_256_LEN);
 
            System.out.println("--> Encrypt data with test buffer");
            byte[] pbClearBuffer = "askdfkasdfaksdfa".getBytes();
 
            byte[] pbEncryptedBuffer = api.encrypt(strSessionKey, pbClearBuffer);
            byte[] pbDecryptedBuffer = api.decrypt(strSessionKey, pbEncryptedBuffer);
 
            System.out.println("--> Test operation");
            if(!Arrays.equals(pbClearBuffer, pbDecryptedBuffer))
            {
                System.out.println("Decrypted buffer and clear text buffer are different!");
            }
 
            System.out.println("--> Delete keys");
            api.deleteKey(strLocalKey);
            api.deleteKey(strPeerKey);
            api.deleteKey(strSessionKey);
 
            api.closeSession();
 
            System.out.println("The process ended sucessfully");
        } catch (TacException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}