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Java example source code file (CTSMode.java)

This example Java source code file (CTSMode.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

cipher, crypto, decryption, encryption, exception, expected, iv1, ivparameterspec, key1, max_keysize, plain1, runtimeexception, secretkeyspec, security, string, sunjce, util

The CTSMode.java Java example source code

/*
 * Copyright (c) 2005, 2007, 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 5083253
 * @run main CTSMode
 * @summary Verify that CTR mode works as expected
 * @author Valerie Peng
 */

import java.util.*;
import java.security.AlgorithmParameters;
import javax.crypto.*;
import javax.crypto.spec.*;

public class CTSMode {

    private final static byte[] toByteArray(String s) {
        char[] c = s.toCharArray();
        byte[] t = new byte[c.length / 2];
        int n = 0;
        int d1 = -1;
        int d2 = -1;
        for (int i = 0; i < c.length; i++) {
            char ch = c[i];
            if (d1 == -1) {
                d1 = Character.digit(ch, 16);
            } else {
                d2 = Character.digit(ch, 16);
                if (d2 != -1) {
                    t[n++] = (byte)((d1 << 4) | d2);
                    d1 = -1;
                    d2 = -1;
                }
            }
        }
        if (d1 != -1) {
            throw new RuntimeException();
        }
        if (n == t.length) {
            return t;
        }
        byte[] b = new byte[n];
        System.arraycopy(t, 0, b, 0, n);
        return b;
    }

    private final static SecretKey KEY1 =
        new SecretKeySpec(toByteArray("636869636b656e207465726979616b69"),
                          "AES");

    private final static IvParameterSpec IV1 =
        new IvParameterSpec(new byte[16]);

    /*
     * Use test vectors, i.e. PLAIN1 and CIPHER1, from the appendix B
     * of RFC 3962 "Advanced Encryption Standard (AES) Encryption for
     * Kerberos 5".
     */
    private final static byte[][] PLAIN1 = {
        toByteArray("4920776f756c64206c696b652074686520"),
        toByteArray("4920776f756c64206c696b6520746865" +
                    "2047656e6572616c20476175277320"),
        toByteArray("4920776f756c64206c696b6520746865" +
                    "2047656e6572616c2047617527732043"),
        toByteArray("4920776f756c64206c696b6520746865" +
                    "2047656e6572616c2047617527732043" +
                    "6869636b656e2c20706c656173652c"),
        toByteArray("4920776f756c64206c696b6520746865" +
                    "2047656e6572616c2047617527732043" +
                    "6869636b656e2c20706c656173652c20"),
        toByteArray("4920776f756c64206c696b6520746865" +
                    "2047656e6572616c2047617527732043" +
                    "6869636b656e2c20706c656173652c20" +
                    "616e6420776f6e746f6e20736f75702e")
    };
    private final static byte[][] CIPHER1 = {
        toByteArray("c6353568f2bf8cb4d8a580362da7ff7f97"),
        toByteArray("fc00783e0efdb2c1d445d4c8eff7ed22" +
                    "97687268d6ecccc0c07b25e25ecfe5"),
        toByteArray("39312523a78662d5be7fcbcc98ebf5a8" +
                    "97687268d6ecccc0c07b25e25ecfe584"),
        toByteArray("97687268d6ecccc0c07b25e25ecfe584" +
                    "b3fffd940c16a18c1b5549d2f838029e" +
                    "39312523a78662d5be7fcbcc98ebf5"),
        toByteArray("97687268d6ecccc0c07b25e25ecfe584" +
                    "9dad8bbb96c4cdc03bc103e1a194bbd8" +
                    "39312523a78662d5be7fcbcc98ebf5a8"),
        toByteArray("97687268d6ecccc0c07b25e25ecfe584" +
                    "39312523a78662d5be7fcbcc98ebf5a8" +
                    "4807efe836ee89a526730dbc2f7bc840" +
                    "9dad8bbb96c4cdc03bc103e1a194bbd8"),
    };

    private final static byte[] IV2_SRC =
        toByteArray("11223344556677880011223344556677");

    private final static String[] ALGORITHMS2 = {
        "DES", "DESede", "Blowfish", "AES"
    };
    private final static int[] KEYSIZES2 = {
        8, 24, 16, 16
    };

    private static String toString(byte[] b) {
        StringBuffer sb = new StringBuffer(b.length * 3);
        for (int i = 0; i < b.length; i++) {
            int k = b[i] & 0xff;
            if (i != 0) {
                sb.append(':');
            }
            sb.append(Character.forDigit(k >> 4, 16));
            sb.append(Character.forDigit(k & 0xf, 16));
        }
        return sb.toString();
    }

    public static void main(String[] args) throws Exception {
        test1();
        test2();
        test3();
   }

    /**
     * Test with the test vectors and see if results match.
     */
    private static void test1() throws Exception {
        for (int i = 0; i < PLAIN1.length; i++) {
            String algo = KEY1.getAlgorithm();
            int MAX_KEYSIZE = Cipher.getMaxAllowedKeyLength(algo);
            if (KEY1.getEncoded().length > MAX_KEYSIZE) {
                // skip tests using keys whose length exceeds
                // what's configured in jce jurisdiction policy files.
                continue;
            }
            System.out.println("Running test1_" + i +  " (" + algo + ")");
            Cipher cipher = Cipher.getInstance(algo+ "/CTS/NoPadding",
                                               "SunJCE");
            byte[] plainText = PLAIN1[i];
            byte[] cipherText = CIPHER1[i];
            cipher.init(Cipher.ENCRYPT_MODE, KEY1, IV1);
            byte[] enc = cipher.doFinal(plainText);
            if (Arrays.equals(cipherText, enc) == false) {
                System.out.println("plain:  " + toString(plainText));
                System.out.println("cipher: " + toString(cipherText));
                System.out.println("actual: " + toString(enc));
                throw new RuntimeException("Encryption failure for test " + i);
            }
            cipher.init(Cipher.DECRYPT_MODE, KEY1, IV1);
            byte[] dec = cipher.doFinal(cipherText);
            if (Arrays.equals(plainText, dec) == false) {
                System.out.println("cipher: " + toString(cipherText));
                System.out.println("plain:  " + toString(plainText));
                System.out.println("actual: " + toString(enc));
                throw new RuntimeException("Decryption failure for test " + i);
            }
        }
    }

    /**
     * Test with a combination of update/doFinal calls and make
     * sure that same data is recovered after decryption.
     */
    private static void test2() throws Exception {
        for (int i = 0; i < ALGORITHMS2.length; i++) {
            String algo = ALGORITHMS2[i];
            System.out.println("Running test2_" + i +  " (" + algo + ")");
            int keySize = KEYSIZES2[i];
            int MAX_KEYSIZE = Cipher.getMaxAllowedKeyLength(algo);
            if (keySize > MAX_KEYSIZE) {
                // skip tests using keys whose length exceeds
                // what's configured in jce jurisdiction policy files.
                continue;
            }
            Cipher cipher =
                Cipher.getInstance(algo+"/CTS/NoPadding", "SunJCE");
            int blockSize = cipher.getBlockSize();
            SecretKeySpec key = new SecretKeySpec(new byte[keySize], algo);
            // Make sure encryption works for inputs with valid length
            byte[] plainText = PLAIN1[3];
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] cipherText = new byte[plainText.length];
            int firstPartLen = blockSize + 1;
            int processed1 = cipher.update(plainText, 0, firstPartLen,
                                           cipherText, 0);
            int processed2 = cipher.doFinal(plainText, firstPartLen,
                                            plainText.length-firstPartLen,
                                            cipherText, processed1);
            AlgorithmParameters params = cipher.getParameters();
            if ((processed1 + processed2) != plainText.length) {
                System.out.println("processed1 = " + processed1);
                System.out.println("processed2 = " + processed2);
                System.out.println("total length = " + plainText.length);
                throw new RuntimeException("Encryption failure for test " + i);
            }
            // Make sure IllegalBlockSizeException is thrown for inputs
            // with less-than-a-block length
            try {
                cipher.doFinal(new byte[blockSize-1]);
                throw new RuntimeException("Expected IBSE is not thrown");
            } catch (IllegalBlockSizeException ibse) {
            }
            // Make sure data is encrypted as in CBC mode for inputs
            // which is exactly one block long
            IvParameterSpec iv2 = new IvParameterSpec(IV2_SRC, 0, blockSize);
            cipher.init(Cipher.ENCRYPT_MODE, key, iv2);
            Cipher cipher2 =
                Cipher.getInstance(algo+"/CBC/NoPadding", "SunJCE");
            cipher2.init(Cipher.ENCRYPT_MODE, key, iv2);

            byte[] eout = cipher.doFinal(IV2_SRC, 0, blockSize);
            byte[] eout2 = cipher2.doFinal(IV2_SRC, 0, blockSize);
            if (!Arrays.equals(eout, eout2)) {
                throw new RuntimeException("Different encryption output " +
                                           "for CBC and CTS");
            }
            // Make sure decryption works for inputs with valid length
            cipher.init(Cipher.DECRYPT_MODE, key, params);
            byte[] recoveredText =
                new byte[cipher.getOutputSize(cipherText.length)];
            processed1 = cipher.update(cipherText, 0, firstPartLen,
                                       recoveredText, 0);
            processed2 = cipher.update(cipherText, firstPartLen,
                                       cipherText.length-firstPartLen,
                                       recoveredText, processed1);
            int processed3 =
                cipher.doFinal(recoveredText, processed1+processed2);
            if ((processed1 + processed2 + processed3) != plainText.length) {
                System.out.println("processed1 = " + processed1);
                System.out.println("processed2 = " + processed2);
                System.out.println("processed3 = " + processed3);
                System.out.println("total length = " + plainText.length);
                throw new RuntimeException("Decryption failure for test " + i);
            }
            if (Arrays.equals(plainText, recoveredText) == false) {
                System.out.println("plain:  " + toString(plainText));
                System.out.println("recovered: " + toString(recoveredText));
                throw new RuntimeException("Decryption failure for test " + i);
            }
            // Make sure IllegalBlockSizeException is thrown for inputs
            // with less-than-a-block length
            try {
                cipher.doFinal(new byte[blockSize-1]);
                throw new RuntimeException("Expected IBSE is not thrown");
            } catch (IllegalBlockSizeException ibse) {
            }
            // Make sure data is decrypted as in CBC mode for inputs
            // which is exactly one block long
            cipher.init(Cipher.DECRYPT_MODE, key, iv2);
            cipher2.init(Cipher.DECRYPT_MODE, key, iv2);
            byte[] dout = cipher.doFinal(eout);
            byte[] dout2 = cipher2.doFinal(eout2);
            if (!Arrays.equals(dout, dout2)) {
                throw new RuntimeException("Different decryption output " +
                                           "for CBC and CTS");
            }
        }
    }

    /**
     * Test with a shortBuffer and see if encryption/decryption
     * still works correctly afterwards.
     */
    private static void test3() throws Exception {
        // Skip PLAIN1[0, 1, 2] due to their lengths
        for (int i = 3; i < PLAIN1.length; i++) {
            String algo = KEY1.getAlgorithm();
            System.out.println("Running test3_" + i +  " (" + algo + ")");
            int MAX_KEYSIZE = Cipher.getMaxAllowedKeyLength(algo);
            if (KEY1.getEncoded().length > MAX_KEYSIZE) {
                // skip tests using keys whose length exceeds
                // what's configured in jce jurisdiction policy files.
                continue;
            }
            Cipher cipher =
                Cipher.getInstance(algo+ "/CTS/NoPadding", "SunJCE");
            byte[] plainText = PLAIN1[i];
            byte[] cipherText = CIPHER1[i];
            byte[] enc = new byte[plainText.length];
            cipher.init(Cipher.ENCRYPT_MODE, KEY1, IV1);
            int halfInput = plainText.length/2;
            int processed1 = cipher.update(plainText, 0, halfInput,
                                           enc, 0);
            try {
                cipher.doFinal(plainText, halfInput,
                               plainText.length-halfInput,
                               new byte[1], 0);
                throw new RuntimeException("Expected Exception is not thrown");
            } catch (ShortBufferException sbe) {
                // expected exception thrown; retry
                int processed2 =
                    cipher.doFinal(plainText, halfInput,
                                   plainText.length-halfInput,
                                   enc, processed1);
                if ((processed1 + processed2) != enc.length) {
                    System.out.println("processed1 = " + processed1);
                    System.out.println("processed2 = " + processed2);
                    System.out.println("total length = " + enc.length);
                    throw new RuntimeException("Encryption length check " +
                                               "failed");
                }
            }
            if (Arrays.equals(cipherText, enc) == false) {
                System.out.println("plain:  " + toString(plainText));
                System.out.println("cipher: " + toString(cipherText));
                System.out.println("actual: " + toString(enc));
                throw new RuntimeException("Encryption failure for test " + i);
            }
            cipher.init(Cipher.DECRYPT_MODE, KEY1, IV1);
            byte[] dec =
                new byte[cipher.getOutputSize(cipherText.length)];
            processed1 = cipher.update(cipherText, 0, halfInput,
                                       dec, 0);
            try {
                cipher.update(cipherText, halfInput,
                              cipherText.length-halfInput,
                              new byte[1], 0);
                throw new RuntimeException("Expected Exception is not thrown");
            } catch (ShortBufferException sbe) {
                // expected exception thrown; retry
                int processed2 = cipher.update(cipherText, halfInput,
                                               cipherText.length-halfInput,
                                               dec, processed1);
                int processed3 =
                    cipher.doFinal(dec, processed1+processed2);
                if ((processed1 + processed2 + processed3) != dec.length) {
                    System.out.println("processed1 = " + processed1);
                    System.out.println("processed2 = " + processed2);
                    System.out.println("processed3 = " + processed3);
                    System.out.println("total length = " + dec.length);
                    throw new RuntimeException("Decryption length check " +
                                               "failed");
                }
            }
            if (Arrays.equals(plainText, dec) == false) {
                System.out.println("cipher: " + toString(cipherText));
                System.out.println("plain:  " + toString(plainText));
                System.out.println("actualD: " + toString(dec));
                throw new RuntimeException("Decryption failure for test " + i);
            }
        }
    }
}

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