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 *

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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 */

/*

 * @test

 * @summary encryption/decryption test for OAEP

 * @author Andreas Sterbenz

 * @key randomness

 */

import java.util.*;

import java.security.*;

import javax.crypto.*;

public class TestOAEP {

    private static Provider cp;

    private static PrivateKey privateKey;

    private static PublicKey publicKey;

    private static Random random = new Random();

    public static void main(String[] args) throws Exception {

        long start = System.currentTimeMillis();

        cp = Security.getProvider("SunJCE");

        System.out.println("Testing provider " + cp.getName() + "...");

        Provider kfp = Security.getProvider("SunRsaSign");

        KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA", kfp);

        kpg.initialize(768);

        KeyPair kp = kpg.generateKeyPair();

        privateKey = kp.getPrivate();

        publicKey = kp.getPublic();

        Cipher.getInstance("RSA/ECB/OAEPwithMD5andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA1andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA-1andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA-224andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA-256andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA-384andMGF1Padding");

        Cipher.getInstance("RSA/ECB/OAEPwithSHA-512andMGF1Padding");

        // basic test using MD5

        testEncryptDecrypt("MD5", 0);

        testEncryptDecrypt("MD5", 16);

        testEncryptDecrypt("MD5", 62);

        try {

            testEncryptDecrypt("MD5", 63);

            throw new Exception("Unexpectedly completed call");

        } catch (IllegalBlockSizeException e) {

            // ok

            System.out.println(e);

        }

        // basic test using SHA-1

        testEncryptDecrypt("SHA1", 0);

        testEncryptDecrypt("SHA1", 16);

        testEncryptDecrypt("SHA1", 54);

        try {

            testEncryptDecrypt("SHA1", 55);

            throw new Exception("Unexpectedly completed call");

        } catch (IllegalBlockSizeException e) {

            // ok

            System.out.println(e);

        }

        // tests alias works

        testEncryptDecrypt("SHA-1", 16);

        }

        }

        // 768 bit key too short for OAEP with 64 byte digest

        try {

            testEncryptDecrypt("SHA-512", 1);

            throw new Exception("Unexpectedly completed call");

        } catch (InvalidKeyException e) {

            // ok

            System.out.println(e);

        }

        Cipher c;

        byte[] enc;

        byte[] data = new byte[16];

        random.nextBytes(data);

        try {

            c = Cipher.getInstance("RSA/ECB/OAEPwithFOOandMGF1Padding", cp);

            throw new Exception("Unexpectedly completed call");

        } catch (NoSuchPaddingException e) {

            // ok

            System.out.println(e);

        }

        c = Cipher.getInstance("RSA/ECB/OAEPwithMD5andMGF1Padding", cp);

        // cannot "sign" using OAEP

        try {

            c.init(Cipher.ENCRYPT_MODE, privateKey);

            throw new Exception("Unexpectedly completed call");

        } catch (InvalidKeyException e) {

            // ok

            System.out.println(e);

        }

        // cannot "verify" using OAEP

        try {

            c.init(Cipher.DECRYPT_MODE, publicKey);

            throw new Exception("Unexpectedly completed call");

        } catch (InvalidKeyException e) {

            // ok

            System.out.println(e);

        }

        // decryption failure

        c.init(Cipher.DECRYPT_MODE, privateKey);

        try {

            c.doFinal(data);

            throw new Exception("Unexpectedly completed call");

        } catch (BadPaddingException e) {

            // ok

            System.out.println(e);

        }

        // wrong hash length

        c.init(Cipher.ENCRYPT_MODE, publicKey);

        enc = c.doFinal(data);

        c = Cipher.getInstance("RSA/ECB/OAEPwithSHA1andMGF1Padding", cp);

        c.init(Cipher.DECRYPT_MODE, privateKey);

        try {

            c.doFinal(enc);

            throw new Exception("Unexpectedly completed call");

        } catch (BadPaddingException e) {

            // ok

            System.out.println(e);

        }

/* MD2 not supported with OAEP

        // wrong hash value

        c = Cipher.getInstance("RSA/ECB/OAEPwithMD2andMGF1Padding", cp);

        c.init(Cipher.DECRYPT_MODE, privateKey);

        try {

            c.doFinal(enc);

            throw new Exception("Unexpectedly completed call");

        } catch (BadPaddingException e) {

            // ok

            System.out.println(e);

        }

*/

        // wrong padding type

        c = Cipher.getInstance("RSA/ECB/PKCS1Padding", cp);

        c.init(Cipher.ENCRYPT_MODE, publicKey);

        enc = c.doFinal(data);

        c = Cipher.getInstance("RSA/ECB/OAEPwithSHA1andMGF1Padding", cp);

        c.init(Cipher.DECRYPT_MODE, privateKey);

        try {

            c.doFinal(enc);

            throw new Exception("Unexpectedly completed call");

        } catch (BadPaddingException e) {

            // ok

            System.out.println(e);

        }

        long stop = System.currentTimeMillis();

        System.out.println("Done (" + (stop - start) + " ms).");

    }

    // NOTE: OAEP can process up to (modLen - 2*digestLen - 2) bytes of data

    private static void testEncryptDecrypt(String hashAlg, int dataLength) throws Exception {

        System.out.println("Testing OAEP with hash " + hashAlg + ", " + dataLength + " bytes");

        Cipher c = Cipher.getInstance("RSA/ECB/OAEPwith" + hashAlg + "andMGF1Padding", cp);

        c.init(Cipher.ENCRYPT_MODE, publicKey);

        byte[] data = new byte[dataLength];

        byte[] enc = c.doFinal(data);

        c.init(Cipher.DECRYPT_MODE, privateKey);

        byte[] dec = c.doFinal(enc);

        if (Arrays.equals(data, dec) == false) {

            throw new Exception("Data does not match");

        }

    }

}