/*

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * 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

 * @bug 8036970

 * @summary Ensure that Cipher object is still usable after SBE.

 * @author Valerie Peng

 */

import java.security.*;

import javax.crypto.*;

import javax.crypto.spec.*;

import java.math.*;

import java.util.*;

public class TestGCMWithSBE extends UcryptoTest {

    private static final byte[] PT = new byte[32];

    private static final byte[] ONE_BYTE = new byte[1];

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

        main(new TestGCMWithSBE(), null);

    }

    public void doTest(Provider p) throws Exception {

        Cipher c;

        try {

            c = Cipher.getInstance("AES/GCM/NoPadding", p);

        } catch (NoSuchAlgorithmException nsae) {

            System.out.println("Skipping Test due to No GCM support");

            return;

        }

        SecretKey key = new SecretKeySpec(new byte[16], "AES");

        c.init(Cipher.ENCRYPT_MODE, key);

        // test SBE with update calls

        byte[] ct1 = null;

        try {

            c.update(PT, 0, PT.length, ONE_BYTE);

        } catch (ShortBufferException sbe) {

            // retry should work

            ct1 = c.update(PT, 0, PT.length);

        }

        byte[] ct2PlusTag = null;

        // test SBE with doFinal calls

        try {

            c.doFinal(ONE_BYTE, 0);

        } catch (ShortBufferException sbe) {

            // retry should work

            ct2PlusTag = c.doFinal();

        }

        // Validate the retrieved parameters against the IV and tag length.

        AlgorithmParameters params = c.getParameters();

        if (params == null) {

            throw new Exception("getParameters() should not return null");

        }

        GCMParameterSpec spec = params.getParameterSpec(GCMParameterSpec.class);

        if (spec.getTLen() != (ct1.length + ct2PlusTag.length - PT.length)*8) {

            throw new Exception("Parameters contains incorrect TLen value");

        }

        if (!Arrays.equals(spec.getIV(), c.getIV())) {

            throw new Exception("Parameters contains incorrect IV value");

        }

        // Should be ok to use the same key+iv for decryption

        c.init(Cipher.DECRYPT_MODE, key, params);

        byte[] pt1 = c.update(ct1);

        if (pt1 != null && pt1.length != 0) {

            throw new Exception("Recovered text should not be returned "

                + "to caller before tag verification");

        }

        byte[] pt2 = null;

        try {

            c.doFinal(ct2PlusTag, 0, ct2PlusTag.length, ONE_BYTE);

        } catch (ShortBufferException sbe) {

            // retry should work

            pt2 = c.doFinal(ct2PlusTag);

        }

        if (!Arrays.equals(pt2, PT)) {

            throw new Exception("decryption result mismatch");

        }

        System.out.println("Test Passed!");

    }

}