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

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/**

 * @test

 * @bug 8181386

 * @summary CipherSpi ByteBuffer to byte array conversion fails for

 *          certain data overlap conditions

 * @run main CipherByteBufferOverwriteTest 0 false

 * @run main CipherByteBufferOverwriteTest 0 true

 * @run main CipherByteBufferOverwriteTest 4 false

 * @run main CipherByteBufferOverwriteTest 4 true

 */

import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import java.nio.ByteBuffer;

import java.util.Arrays;

public class CipherByteBufferOverwriteTest {

    private static final boolean DEBUG = false;

    private static final String TRANSFORMATION = "AES/CBC/PKCS5Padding";

    // must be larger than the temp array size, i.e. 4096, hardcoded in

    // javax.crypto.CipherSpi class

    private static final int PLAINTEXT_SIZE = 8192;

    // leave room for padding

    private static final int CIPHERTEXT_BUFFER_SIZE = PLAINTEXT_SIZE + 32;

    private static final SecretKey KEY = new SecretKeySpec(new byte[16], "AES");

    private static final AlgorithmParameterSpec PARAMS =

            new IvParameterSpec(new byte[16]);

    private static ByteBuffer inBuf;

    private static ByteBuffer outBuf;

    private enum BufferType {

        ALLOCATE, DIRECT, WRAP;

    }

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

        int offset = Integer.parseInt(args[0]);

        boolean useRO = Boolean.parseBoolean(args[1]);

        // an all-zeros plaintext is the easiest way to demonstrate the issue,

        // but it fails with any plaintext, of course

        byte[] expectedPT = new byte[PLAINTEXT_SIZE];

        byte[] buf = new byte[offset + CIPHERTEXT_BUFFER_SIZE];

        System.arraycopy(expectedPT, 0, buf, 0, PLAINTEXT_SIZE);

        // generate expected cipher text using byte[] methods

        Cipher c = Cipher.getInstance(TRANSFORMATION);

        c.init(Cipher.ENCRYPT_MODE, KEY, PARAMS);

        byte[] expectedCT = c.doFinal(expectedPT);

        // Test#1: against ByteBuffer generated with allocate(int) call

        prepareBuffers(BufferType.ALLOCATE, useRO, buf.length,

                buf, 0, PLAINTEXT_SIZE, offset);

        runTest(offset, expectedPT, expectedCT);

        System.out.println("\tALLOCATE: passed");

        // Test#2: against direct ByteBuffer

        prepareBuffers(BufferType.DIRECT, useRO, buf.length,

                buf, 0, PLAINTEXT_SIZE, offset);

        System.out.println("\tDIRECT: passed");

        runTest(offset, expectedPT, expectedCT);

        // Test#3: against ByteBuffer wrapping existing array

        prepareBuffers(BufferType.WRAP, useRO, buf.length,

                buf, 0, PLAINTEXT_SIZE, offset);

        runTest(offset, expectedPT, expectedCT);

        System.out.println("\tWRAP: passed");

        System.out.println("All Tests Passed");

    }

    private static void prepareBuffers(BufferType type,

            boolean useRO, int bufSz, byte[] in, int inOfs, int inLen,

            int outOfs) {

        switch (type) {

            case ALLOCATE:

                outBuf = ByteBuffer.allocate(bufSz);

                inBuf = outBuf.slice();

                inBuf.put(in, inOfs, inLen);

                inBuf.rewind();

                inBuf.limit(inLen);

                outBuf.position(outOfs);

                break;

            case DIRECT:

                outBuf = ByteBuffer.allocateDirect(bufSz);

                inBuf = outBuf.slice();

                inBuf.put(in, inOfs, inLen);

                inBuf.rewind();

                inBuf.limit(inLen);

                outBuf.position(outOfs);

                break;

            case WRAP:

                if (in.length < bufSz) {

                    throw new RuntimeException("ERROR: Input buffer too small");

                }

                outBuf = ByteBuffer.wrap(in);

                inBuf = ByteBuffer.wrap(in, inOfs, inLen);

                outBuf.position(outOfs);

                break;

        }

        if (useRO) {

            inBuf = inBuf.asReadOnlyBuffer();

        }

        if (DEBUG) {

            System.out.println("inBuf, pos = " + inBuf.position() +

                ", capacity = " + inBuf.capacity() +

                ", limit = " + inBuf.limit() +

                ", remaining = " + inBuf.remaining());

            System.out.println("outBuf, pos = " + outBuf.position() +

                ", capacity = " + outBuf.capacity() +

                ", limit = " + outBuf.limit() +

                ", remaining = " + outBuf.remaining());

        }

    }

    private static void runTest(int ofs, byte[] expectedPT, byte[] expectedCT)

            throws Exception {

        Cipher c = Cipher.getInstance(TRANSFORMATION);

        c.init(Cipher.ENCRYPT_MODE, KEY, PARAMS);

        int ciphertextSize = c.doFinal(inBuf, outBuf);

        // read out the encrypted result

        outBuf.position(ofs);

        byte[] finalCT = new byte[ciphertextSize];

        if (DEBUG) {

            System.out.println("runTest, ciphertextSize = " + ciphertextSize);

            System.out.println("runTest, ofs = " + ofs +

                ", remaining = " + finalCT.length +

                ", limit = " + outBuf.limit());

        }

        outBuf.get(finalCT);

        if (!Arrays.equals(finalCT, expectedCT)) {

            throw new Exception("ERROR: Ciphertext does not match");

        }

        // now do decryption

        outBuf.position(ofs);

        outBuf.limit(ofs + ciphertextSize);

        c.init(Cipher.DECRYPT_MODE, KEY, PARAMS);

        ByteBuffer finalPTBuf = ByteBuffer.allocate(

                c.getOutputSize(outBuf.remaining()));

        c.doFinal(outBuf, finalPTBuf);

        // read out the decrypted result

        finalPTBuf.flip();

        byte[] finalPT = new byte[finalPTBuf.remaining()];

        finalPTBuf.get(finalPT);

        if (!Arrays.equals(finalPT, expectedPT)) {

            throw new Exception("ERROR: Plaintext does not match");

        }

    }

}