Java example source code file (TestOAEP.java)

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Java - Java tags/keywords

badpaddingexception, cipher, crypto, exception, illegalblocksizeexception, invalidkeyexception, md5, provider, random, rsa\/ecb\/oaepwithmd5andmgf1padding, rsa\/ecb\/oaepwithsha1andmgf1padding, security, sha-224, sha-256, sha1, unexpectedly, util

The TestOAEP.java Java example source code

/*
 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 4894151
 * @summary encryption/decryption test for OAEP
 * @author Andreas Sterbenz
 */

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);

        // basic test using SHA-224
        testEncryptDecrypt("SHA-224", 0);
        testEncryptDecrypt("SHA-224", 16);
        testEncryptDecrypt("SHA-224", 38);
        try {
            testEncryptDecrypt("SHA-224", 39);
            throw new Exception("Unexpectedly completed call");
        } catch (IllegalBlockSizeException e) {
            // ok
            System.out.println(e);
        }

        // basic test using SHA-256
        testEncryptDecrypt("SHA-256", 0);
        testEncryptDecrypt("SHA-256", 16);
        testEncryptDecrypt("SHA-256", 30);
        try {
            testEncryptDecrypt("SHA-256", 31);
            throw new Exception("Unexpectedly completed call");
        } catch (IllegalBlockSizeException e) {
            // ok
            System.out.println(e);
        }

        // 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");
        }
    }
}