    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.io.input;
    018
    019import java.io.IOException;
    020import java.io.InputStream;
    021import java.security.MessageDigest;
    022import java.security.NoSuchAlgorithmException;
    023import java.security.Provider;
    024import java.util.Arrays;
    025import java.util.Objects;
    026
    027/**
    028 * Calculates a checksum using a {@link MessageDigest}, for example, a SHA-512 sum.
    029 * <p>
    030 * To build an instance, use {@link Builder}.
    031 * </p>
    032 * <p>
    033 * See the MessageDigest section in the <a href= "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#MessageDigest"> Java
    034 * Cryptography Architecture Standard Algorithm Name Documentation</a> for information about standard algorithm names.
    035 * </p>
    036 * <p>
    037 * <em>Note</em>: Neither {@link ObservableInputStream}, nor {@link MessageDigest}, are thread safe, so is {@link MessageDigestCalculatingInputStream}.
    038 * </p>
    039 *
    040 * @see Builder
    041 * @deprecated Use {@link MessageDigestInputStream}.
    042 */
    043@Deprecated
    044public class MessageDigestCalculatingInputStream extends ObservableInputStream {
    045
    046    // @formatter:off
    047    /**
    048     * Builds a new {@link MessageDigestCalculatingInputStream}.
    049     *
    050     * <p>
    051     * For example:
    052     * </p>
    053     * <pre>{@code
    054     * MessageDigestCalculatingInputStream s = MessageDigestCalculatingInputStream.builder()
    055     *   .setPath(path)
    056     *   .setMessageDigest("SHA-512")
    057     *   .get();}
    058     * </pre>
    059     * <p>
    060     * <em>The MD5 cryptographic algorithm is weak and should not be used.</em>
    061     * </p>
    062     *
    063     * @see #get()
    064     * @since 2.12.0
    065     */
    066    // @formatter:on
    067    public static class Builder extends AbstractBuilder<Builder> {
    068
    069        private MessageDigest messageDigest;
    070
    071        /**
    072         * Constructs a new builder of {@link MessageDigestCalculatingInputStream}.
    073         * <p>
    074         * The default for compatibility is the MD5 cryptographic algorithm which is weak and should not be used.
    075         * </p>
    076         */
    077        public Builder() {
    078            try {
    079                this.messageDigest = getDefaultMessageDigest();
    080            } catch (final NoSuchAlgorithmException e) {
    081                // Should not happen.
    082                throw new IllegalStateException(e);
    083            }
    084        }
    085
    086        /**
    087         * Builds a new {@link MessageDigestCalculatingInputStream}.
    088         * <p>
    089         * You must set an aspect that supports {@link #getInputStream()}, otherwise, this method throws an exception.
    090         * </p>
    091         * <p>
    092         * This builder uses the following aspects:
    093         * </p>
    094         * <ul>
    095         * <li>{@link #getInputStream()} gets the target aspect.</li>
    096         * <li>{@link MessageDigest}</li>
    097         * </ul>
    098         *
    099         * @return a new instance.
    100         * @throws NullPointerException if messageDigest is null.
    101         * @throws IllegalStateException         if the {@code origin} is {@code null}.
    102         * @throws UnsupportedOperationException if the origin cannot be converted to an {@link InputStream}.
    103         * @throws IOException                   if an I/O error occurs converting to an {@link InputStream} using {@link #getInputStream()}.
    104         * @see #getInputStream()
    105         * @see #getUnchecked()
    106         */
    107        @Override
    108        public MessageDigestCalculatingInputStream get() throws IOException {
    109            setObservers(Arrays.asList(new MessageDigestMaintainingObserver(messageDigest)));
    110            return new MessageDigestCalculatingInputStream(this);
    111        }
    112
    113        /**
    114         * Sets the message digest.
    115         * <p>
    116         * <em>The MD5 cryptographic algorithm is weak and should not be used.</em>
    117         * </p>
    118         *
    119         * @param messageDigest the message digest.
    120         */
    121        public void setMessageDigest(final MessageDigest messageDigest) {
    122            this.messageDigest = messageDigest;
    123        }
    124
    125        /**
    126         * Sets the name of the name of the message digest algorithm.
    127         * <p>
    128         * <em>The MD5 cryptographic algorithm is weak and should not be used.</em>
    129         * </p>
    130         *
    131         * @param algorithm the name of the algorithm. See the MessageDigest section in the
    132         *                  <a href= "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#MessageDigest"> Java Cryptography
    133         *                  Architecture Standard Algorithm Name Documentation</a> for information about standard algorithm names.
    134         * @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for the specified algorithm.
    135         */
    136        public void setMessageDigest(final String algorithm) throws NoSuchAlgorithmException {
    137            this.messageDigest = MessageDigest.getInstance(algorithm);
    138        }
    139
    140    }
    141
    142    /**
    143     * Maintains the message digest.
    144     */
    145    public static class MessageDigestMaintainingObserver extends Observer {
    146        private final MessageDigest messageDigest;
    147
    148        /**
    149         * Constructs an MessageDigestMaintainingObserver for the given MessageDigest.
    150         *
    151         * @param messageDigest the message digest to use.
    152         * @throws NullPointerException if messageDigest is null.
    153         */
    154        public MessageDigestMaintainingObserver(final MessageDigest messageDigest) {
    155            this.messageDigest = Objects.requireNonNull(messageDigest, "messageDigest");
    156        }
    157
    158        @Override
    159        public void data(final byte[] input, final int offset, final int length) throws IOException {
    160            messageDigest.update(input, offset, length);
    161        }
    162
    163        @Override
    164        public void data(final int input) throws IOException {
    165            messageDigest.update((byte) input);
    166        }
    167    }
    168
    169    /**
    170     * The default message digest algorithm {@code "MD5"}.
    171     * <p>
    172     * The MD5 cryptographic algorithm is weak and should not be used.
    173     * </p>
    174     */
    175    private static final String DEFAULT_ALGORITHM = "MD5";
    176
    177    /**
    178     * Constructs a new {@link Builder}.
    179     *
    180     * @return a new {@link Builder}.
    181     * @since 2.12.0
    182     */
    183    public static Builder builder() {
    184        return new Builder();
    185    }
    186
    187    /**
    188     * Gets a MessageDigest object that implements the default digest algorithm {@code "MD5"}.
    189     * <p>
    190     * The MD5 cryptographic algorithm is weak and should not be used.
    191     * </p>
    192     *
    193     * @return a Message Digest object that implements the default algorithm.
    194     * @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation.
    195     * @see Provider
    196     */
    197    static MessageDigest getDefaultMessageDigest() throws NoSuchAlgorithmException {
    198        return MessageDigest.getInstance(DEFAULT_ALGORITHM);
    199    }
    200
    201    private final MessageDigest messageDigest;
    202
    203    private MessageDigestCalculatingInputStream(final Builder builder) throws IOException {
    204        super(builder);
    205        this.messageDigest = builder.messageDigest;
    206    }
    207
    208    /**
    209     * Constructs a new instance, which calculates a signature on the given stream, using a {@link MessageDigest} with the "MD5" algorithm.
    210     * <p>
    211     * The MD5 algorithm is weak and should not be used.
    212     * </p>
    213     *
    214     * @param inputStream the stream to calculate the message digest for.
    215     * @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for the specified algorithm.
    216     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}.
    217     */
    218    @Deprecated
    219    public MessageDigestCalculatingInputStream(final InputStream inputStream) throws NoSuchAlgorithmException {
    220        this(inputStream, getDefaultMessageDigest());
    221    }
    222
    223    /**
    224     * Constructs a new instance, which calculates a signature on the given stream, using the given {@link MessageDigest}.
    225     * <p>
    226     * The MD5 cryptographic algorithm is weak and should not be used.
    227     * </p>
    228     *
    229     * @param inputStream   the stream to calculate the message digest for.
    230     * @param messageDigest the message digest to use.
    231     * @throws NullPointerException if messageDigest is null.
    232     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}.
    233     */
    234    @Deprecated
    235    public MessageDigestCalculatingInputStream(final InputStream inputStream, final MessageDigest messageDigest) {
    236        super(inputStream, new MessageDigestMaintainingObserver(messageDigest));
    237        this.messageDigest = messageDigest;
    238    }
    239
    240    /**
    241     * Constructs a new instance, which calculates a signature on the given stream, using a {@link MessageDigest} with the given algorithm.
    242     * <p>
    243     * The MD5 cryptographic algorithm is weak and should not be used.
    244     * </p>
    245     *
    246     * @param inputStream the stream to calculate the message digest for.
    247     * @param algorithm   the name of the algorithm requested. See the MessageDigest section in the
    248     *                    <a href= "https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#MessageDigest"> Java Cryptography
    249     *                    Architecture Standard Algorithm Name Documentation</a> for information about standard algorithm names.
    250     * @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for the specified algorithm.
    251     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}.
    252     */
    253    @Deprecated
    254    public MessageDigestCalculatingInputStream(final InputStream inputStream, final String algorithm) throws NoSuchAlgorithmException {
    255        this(inputStream, MessageDigest.getInstance(algorithm));
    256    }
    257
    258    /**
    259     * Gets the {@link MessageDigest}, which is being used for generating the checksum.
    260     * <p>
    261     * <em>Note</em>: The checksum will only reflect the data, which has been read so far. This is probably not, what you expect. Make sure, that the complete
    262     * data has been read, if that is what you want. The easiest way to do so is by invoking {@link #consume()}.
    263     * </p>
    264     *
    265     * @return the message digest used.
    266     */
    267    public MessageDigest getMessageDigest() {
    268        return messageDigest;
    269    }
    270}