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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2013 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.compression;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.internal.ObjectUtil;

import java.util.List;
import java.util.zip.CRC32;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

/**
 * Decompress a {@link ByteBuf} using the inflate algorithm.
 */
public class JdkZlibDecoder extends ZlibDecoder {
    private static final int FHCRC = 0x02;
    private static final int FEXTRA = 0x04;
    private static final int FNAME = 0x08;
    private static final int FCOMMENT = 0x10;
    private static final int FRESERVED = 0xE0;

    private Inflater inflater;
    private final byte[] dictionary;

    // GZIP related
    private final ByteBufChecksum crc;
    private final boolean decompressConcatenated;

    private enum GzipState {
        HEADER_START,
        HEADER_END,
        FLG_READ,
        XLEN_READ,
        SKIP_FNAME,
        SKIP_COMMENT,
        PROCESS_FHCRC,
        FOOTER_START,
    }

    private GzipState gzipState = GzipState.HEADER_START;
    private int flags = -1;
    private int xlen = -1;

    private volatile boolean finished;

    private boolean decideZlibOrNone;

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB}).
     */
    public JdkZlibDecoder() {
        this(ZlibWrapper.ZLIB, null, false, 0);
    }

    /**
     * Creates a new instance with the default wrapper ({@link ZlibWrapper#ZLIB})
     * and the specified maximum buffer allocation.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     */
    public JdkZlibDecoder(int maxAllocation) {
        this(ZlibWrapper.ZLIB, null, false, maxAllocation);
    }

    /**
     * Creates a new instance with the specified preset dictionary. The wrapper
     * is always {@link ZlibWrapper#ZLIB} because it is the only format that
     * supports the preset dictionary.
     */
    public JdkZlibDecoder(byte[] dictionary) {
        this(ZlibWrapper.ZLIB, dictionary, false, 0);
    }

    /**
     * Creates a new instance with the specified preset dictionary and maximum buffer allocation.
     * The wrapper is always {@link ZlibWrapper#ZLIB} because it is the only format that
     * supports the preset dictionary.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     */
    public JdkZlibDecoder(byte[] dictionary, int maxAllocation) {
        this(ZlibWrapper.ZLIB, dictionary, false, maxAllocation);
    }

    /**
     * Creates a new instance with the specified wrapper.
     * Be aware that only {@link ZlibWrapper#GZIP}, {@link ZlibWrapper#ZLIB} and {@link ZlibWrapper#NONE} are
     * supported atm.
     */
    public JdkZlibDecoder(ZlibWrapper wrapper) {
        this(wrapper, null, false, 0);
    }

    /**
     * Creates a new instance with the specified wrapper and maximum buffer allocation.
     * Be aware that only {@link ZlibWrapper#GZIP}, {@link ZlibWrapper#ZLIB} and {@link ZlibWrapper#NONE} are
     * supported atm.
     *
     * @param maxAllocation
     *          Maximum size of the decompression buffer. Must be >= 0.
     *          If zero, maximum size is decided by the {@link ByteBufAllocator}.
     */
    public JdkZlibDecoder(ZlibWrapper wrapper, int maxAllocation) {
        this(wrapper, null, false, maxAllocation);
    }

    public JdkZlibDecoder(ZlibWrapper wrapper, boolean decompressConcatenated) {
        this(wrapper, null, decompressConcatenated, 0);
    }

    public JdkZlibDecoder(ZlibWrapper wrapper, boolean decompressConcatenated, int maxAllocation) {
        this(wrapper, null, decompressConcatenated, maxAllocation);
    }

    public JdkZlibDecoder(boolean decompressConcatenated) {
        this(ZlibWrapper.GZIP, null, decompressConcatenated, 0);
    }

    public JdkZlibDecoder(boolean decompressConcatenated, int maxAllocation) {
        this(ZlibWrapper.GZIP, null, decompressConcatenated, maxAllocation);
    }

    private JdkZlibDecoder(ZlibWrapper wrapper, byte[] dictionary, boolean decompressConcatenated, int maxAllocation) {
        super(maxAllocation);

        ObjectUtil.checkNotNull(wrapper, "wrapper");

        this.decompressConcatenated = decompressConcatenated;
        switch (wrapper) {
            case GZIP:
                inflater = new Inflater(true);
                crc = ByteBufChecksum.wrapChecksum(new CRC32());
                break;
            case NONE:
                inflater = new Inflater(true);
                crc = null;
                break;
            case ZLIB:
                inflater = new Inflater();
                crc = null;
                break;
            case ZLIB_OR_NONE:
                // Postpone the decision until decode(...) is called.
                decideZlibOrNone = true;
                crc = null;
                break;
            default:
                throw new IllegalArgumentException("Only GZIP or ZLIB is supported, but you used " + wrapper);
        }
        this.dictionary = dictionary;
    }

    @Override
    public boolean isClosed() {
        return finished;
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        if (finished) {
            // Skip data received after finished.
            in.skipBytes(in.readableBytes());
            return;
        }

        int readableBytes = in.readableBytes();
        if (readableBytes == 0) {
            return;
        }

        if (decideZlibOrNone) {
            // First two bytes are needed to decide if it's a ZLIB stream.
            if (readableBytes < 2) {
                return;
            }

            boolean nowrap = !looksLikeZlib(in.getShort(in.readerIndex()));
            inflater = new Inflater(nowrap);
            decideZlibOrNone = false;
        }

        if (crc != null) {
            if (gzipState != GzipState.HEADER_END) {
                if (gzipState == GzipState.FOOTER_START) {
                    if (!handleGzipFooter(in)) {
                        // Either there was not enough data or the input is finished.
                        return;
                    }
                    // If we consumed the footer we will start with the header again.
                    assert gzipState == GzipState.HEADER_START;
                }
                if (!readGZIPHeader(in)) {
                    // There was not enough data readable to read the GZIP header.
                    return;
                }
                // Some bytes may have been consumed, and so we must re-set the number of readable bytes.
                readableBytes = in.readableBytes();
                if (readableBytes == 0) {
                    return;
                }
            }
        }

        if (inflater.needsInput()) {
            if (in.hasArray()) {
                inflater.setInput(in.array(), in.arrayOffset() + in.readerIndex(), readableBytes);
            } else {
                byte[] array = new byte[readableBytes];
                in.getBytes(in.readerIndex(), array);
                inflater.setInput(array);
            }
        }

        ByteBuf decompressed = prepareDecompressBuffer(ctx, null, inflater.getRemaining() << 1);
        try {
            boolean readFooter = false;
            while (!inflater.needsInput()) {
                byte[] outArray = decompressed.array();
                int writerIndex = decompressed.writerIndex();
                int outIndex = decompressed.arrayOffset() + writerIndex;
                int writable = decompressed.writableBytes();
                int outputLength = inflater.inflate(outArray, outIndex, writable);
                if (outputLength > 0) {
                    decompressed.writerIndex(writerIndex + outputLength);
                    if (crc != null) {
                        crc.update(outArray, outIndex, outputLength);
                    }
                } else  if (inflater.needsDictionary()) {
                    if (dictionary == null) {
                        throw new DecompressionException(
                                "decompression failure, unable to set dictionary as non was specified");
                    }
                    inflater.setDictionary(dictionary);
                }

                if (inflater.finished()) {
                    if (crc == null) {
                        finished = true; // Do not decode anymore.
                    } else {
                        readFooter = true;
                    }
                    break;
                } else {
                    decompressed = prepareDecompressBuffer(ctx, decompressed, inflater.getRemaining() << 1);
                }
            }

            in.skipBytes(readableBytes - inflater.getRemaining());

            if (readFooter) {
                gzipState = GzipState.FOOTER_START;
                handleGzipFooter(in);
            }
        } catch (DataFormatException e) {
            throw new DecompressionException("decompression failure", e);
        } finally {
            if (decompressed.isReadable()) {
                out.add(decompressed);
            } else {
                decompressed.release();
            }
        }
    }

    private boolean handleGzipFooter(ByteBuf in) {
        if (readGZIPFooter(in)) {
            finished = !decompressConcatenated;

            if (!finished) {
                inflater.reset();
                crc.reset();
                gzipState = GzipState.HEADER_START;
                return true;
            }
        }
        return false;
    }

    @Override
    protected void decompressionBufferExhausted(ByteBuf buffer) {
        finished = true;
    }

    @Override
    protected void handlerRemoved0(ChannelHandlerContext ctx) throws Exception {
        super.handlerRemoved0(ctx);
        if (inflater != null) {
            inflater.end();
        }
    }

    private boolean readGZIPHeader(ByteBuf in) {
        switch (gzipState) {
            case HEADER_START:
                if (in.readableBytes() < 10) {
                    return false;
                }
                // read magic numbers
                int magic0 = in.readByte();
                int magic1 = in.readByte();

                if (magic0 != 31) {
                    throw new DecompressionException("Input is not in the GZIP format");
                }
                crc.update(magic0);
                crc.update(magic1);

                int method = in.readUnsignedByte();
                if (method != Deflater.DEFLATED) {
                    throw new DecompressionException("Unsupported compression method "
                            + method + " in the GZIP header");
                }
                crc.update(method);

                flags = in.readUnsignedByte();
                crc.update(flags);

                if ((flags & FRESERVED) != 0) {
                    throw new DecompressionException(
                            "Reserved flags are set in the GZIP header");
                }

                // mtime (int)
                crc.update(in, in.readerIndex(), 4);
                in.skipBytes(4);

                crc.update(in.readUnsignedByte()); // extra flags
                crc.update(in.readUnsignedByte()); // operating system

                gzipState = GzipState.FLG_READ;
                // fall through
            case FLG_READ:
                if ((flags & FEXTRA) != 0) {
                    if (in.readableBytes() < 2) {
                        return false;
                    }
                    int xlen1 = in.readUnsignedByte();
                    int xlen2 = in.readUnsignedByte();
                    crc.update(xlen1);
                    crc.update(xlen2);

                    xlen |= xlen1 << 8 | xlen2;
                }
                gzipState = GzipState.XLEN_READ;
                // fall through
            case XLEN_READ:
                if (xlen != -1) {
                    if (in.readableBytes() < xlen) {
                        return false;
                    }
                    crc.update(in, in.readerIndex(), xlen);
                    in.skipBytes(xlen);
                }
                gzipState = GzipState.SKIP_FNAME;
                // fall through
            case SKIP_FNAME:
                if (!skipIfNeeded(in, FNAME)) {
                    return false;
                }
                gzipState = GzipState.SKIP_COMMENT;
                // fall through
            case SKIP_COMMENT:
                if (!skipIfNeeded(in, FCOMMENT)) {
                    return false;
                }
                gzipState = GzipState.PROCESS_FHCRC;
                // fall through
            case PROCESS_FHCRC:
                if ((flags & FHCRC) != 0) {
                    if (!verifyCrc16(in)) {
                        return false;
                    }
                }
                crc.reset();
                gzipState = GzipState.HEADER_END;
                // fall through
            case HEADER_END:
                return true;
            default:
                throw new IllegalStateException();
        }
    }

    /**
     * Skip bytes in the input if needed until we find the end marker {@code 0x00}.
     * @param   in the input
     * @param   flagMask the mask that should be present in the {@code flags} when we need to skip bytes.
     * @return  {@code true} if the operation is complete and we can move to the next state, {@code false} if we need
     *          the retry again once we have more readable bytes.
     */
    private boolean skipIfNeeded(ByteBuf in, int flagMask) {
        if ((flags & flagMask) != 0) {
            for (;;) {
                if (!in.isReadable()) {
                    // We didnt find the end yet, need to retry again once more data is readable
                    return false;
                }
                int b = in.readUnsignedByte();
                crc.update(b);
                if (b == 0x00) {
                    break;
                }
            }
        }
        // Skip is handled, we can move to the next processing state.
        return true;
    }

    /**
     * Read the GZIP footer.
     *
     * @param   in the input.
     * @return  {@code true} if the footer could be read, {@code false} if the read could not be performed as
     *          the input {@link ByteBuf} doesn't have enough readable bytes (8 bytes).
     */
    private boolean readGZIPFooter(ByteBuf in) {
        if (in.readableBytes() < 8) {
            return false;
        }

        boolean enoughData = verifyCrc(in);
        assert enoughData;

        // read ISIZE and verify
        int dataLength = 0;
        for (int i = 0; i < 4; ++i) {
            dataLength |= in.readUnsignedByte() << i * 8;
        }
        int readLength = inflater.getTotalOut();
        if (dataLength != readLength) {
            throw new DecompressionException(
                    "Number of bytes mismatch. Expected: " + dataLength + ", Got: " + readLength);
        }
        return true;
    }

    /**
     * Verifies CRC.
     *
     * @param   in the input.
     * @return  {@code true} if verification could be performed, {@code false} if verification could not be performed as
     *          the input {@link ByteBuf} doesn't have enough readable bytes (4 bytes).
     */
    private boolean verifyCrc(ByteBuf in) {
        if (in.readableBytes() < 4) {
            return false;
        }
        long crcValue = 0;
        for (int i = 0; i < 4; ++i) {
            crcValue |= (long) in.readUnsignedByte() << i * 8;
        }
        long readCrc = crc.getValue();
        if (crcValue != readCrc) {
            throw new DecompressionException(
                    "CRC value mismatch. Expected: " + crcValue + ", Got: " + readCrc);
        }
        return true;
    }

    private boolean verifyCrc16(ByteBuf in) {
        if (in.readableBytes() < 2) {
            return false;
        }
        long readCrc32 = crc.getValue();
        long crc16Value = 0;
        long readCrc16 = 0; // the two least significant bytes from the CRC32
        for (int i = 0; i < 2; ++i) {
            crc16Value |= (long) in.readUnsignedByte() << (i * 8);
            readCrc16 |= ((readCrc32 >> (i * 8)) & 0xff) << (i * 8);
        }

        if (crc16Value != readCrc16) {
            throw new DecompressionException(
                    "CRC16 value mismatch. Expected: " + crc16Value + ", Got: " + readCrc16);
        }
        return true;
    }

    /*
     * Returns true if the cmf_flg parameter (think: first two bytes of a zlib stream)
     * indicates that this is a zlib stream.
     * 

     * You can lookup the details in the ZLIB RFC:
     * RFC 1950.
     */
    private static boolean looksLikeZlib(short cmf_flg) {
        return (cmf_flg & 0x7800) == 0x7800 &&
                cmf_flg % 31 == 0;
    }
}
    

    

    

            

    

            



    
    






    
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