    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 *      http://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.codec.digest;
    018
    019import java.nio.charset.StandardCharsets;
    020import java.security.MessageDigest;
    021import java.security.SecureRandom;
    022import java.util.Arrays;
    023import java.util.Random;
    024import java.util.concurrent.ThreadLocalRandom;
    025import java.util.regex.Matcher;
    026import java.util.regex.Pattern;
    027
    028/**
    029 * The libc crypt() "$1$" and Apache "$apr1$" MD5-based hash algorithm.
    030 * <p>
    031 * Based on the public domain ("beer-ware") C implementation from Poul-Henning Kamp which was found at: <a
    032 * href="http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libcrypt/crypt-md5.c?rev=1.1;content-type=text%2Fplain">
    033 * crypt-md5.c @ freebsd.org</a>
    034 * </p>
    035 * <p>
    036 * Source:
    037 * </p>
    038 * <pre>
    039 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.1 1999/01/21 13:50:09 brandon Exp $
    040 * </pre>
    041 * <p>
    042 * Conversion to Kotlin and from there to Java in 2012.
    043 * </p>
    044 * <p>
    045 * The C style comments are from the original C code, the ones with "//" from the port.
    046 * </p>
    047 * <p>
    048 * This class is immutable and thread-safe.
    049 * </p>
    050 *
    051 * @since 1.7
    052 */
    053public class Md5Crypt {
    054
    055    /** The Identifier of the Apache variant. */
    056    static final String APR1_PREFIX = "$apr1$";
    057
    058    /** The number of bytes of the final hash. */
    059    private static final int BLOCKSIZE = 16;
    060
    061    /** The Identifier of this crypt() variant. */
    062    static final String MD5_PREFIX = "$1$";
    063
    064    /** The number of rounds of the big loop. */
    065    private static final int ROUNDS = 1000;
    066
    067    /**
    068     * See {@link #apr1Crypt(byte[], String)} for details.
    069     * <p>
    070     * A salt is generated for you using {@link SecureRandom}; your own {@link Random} in
    071     * {@link #apr1Crypt(byte[], Random)}.
    072     * </p>
    073     *
    074     * @param keyBytes plaintext string to hash.
    075     * @return the hash value
    076     * @throws IllegalArgumentException when a {@link java.security.NoSuchAlgorithmException} is caught. *
    077     * @see #apr1Crypt(byte[], String)
    078     */
    079    public static String apr1Crypt(final byte[] keyBytes) {
    080        return apr1Crypt(keyBytes, APR1_PREFIX + B64.getRandomSalt(8));
    081    }
    082
    083    /**
    084     * See {@link #apr1Crypt(byte[], String)} for details.
    085     * <p>
    086     * A salt is generated for you using the user provided {@link Random}.
    087     * </p>
    088     *
    089     * @param keyBytes plaintext string to hash.
    090     * @param random the instance of {@link Random} to use for generating the salt. Consider using {@link SecureRandom}
    091     *            or {@link ThreadLocalRandom}.
    092     * @return the hash value
    093     * @throws IllegalArgumentException when a {@link java.security.NoSuchAlgorithmException} is caught. *
    094     * @see #apr1Crypt(byte[], String)
    095     * @since 1.12
    096     */
    097    public static String apr1Crypt(final byte[] keyBytes, final Random random) {
    098        return apr1Crypt(keyBytes, APR1_PREFIX + B64.getRandomSalt(8, random));
    099    }
    100
    101    /**
    102     * See {@link #apr1Crypt(String, String)} for details.
    103     * <p>
    104     * A salt is generated for you using {@link SecureRandom}
    105     * </p>
    106     *
    107     * @param keyBytes
    108     *            plaintext string to hash.
    109     * @param salt
    110     *            An APR1 salt. The salt may be null, in which case a salt is generated for you using
    111     *            {@link ThreadLocalRandom}; for more secure salts consider using {@link SecureRandom} to generate your
    112     *            own salts.
    113     * @return the hash value
    114     * @throws IllegalArgumentException
    115     *             if the salt does not match the allowed pattern
    116     * @throws IllegalArgumentException
    117     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    118     */
    119    public static String apr1Crypt(final byte[] keyBytes, String salt) {
    120        // to make the md5Crypt regex happy
    121        if (salt != null && !salt.startsWith(APR1_PREFIX)) {
    122            salt = APR1_PREFIX + salt;
    123        }
    124        return Md5Crypt.md5Crypt(keyBytes, salt, APR1_PREFIX);
    125    }
    126
    127    /**
    128     * See {@link #apr1Crypt(String, String)} for details.
    129     * <p>
    130     * A salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
    131     * {@link SecureRandom} to generate your own salts and calling {@link #apr1Crypt(byte[], String)}.
    132     * </p>
    133     *
    134     * @param keyBytes
    135     *            plaintext string to hash.
    136     * @return the hash value
    137     * @throws IllegalArgumentException
    138     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    139     * @see #apr1Crypt(byte[], String)
    140     */
    141    public static String apr1Crypt(final String keyBytes) {
    142        return apr1Crypt(keyBytes.getBytes(StandardCharsets.UTF_8));
    143    }
    144
    145    /**
    146     * Generates an Apache htpasswd compatible "$apr1$" MD5 based hash value.
    147     * <p>
    148     * The algorithm is identical to the crypt(3) "$1$" one but produces different outputs due to the different salt
    149     * prefix.
    150     * </p>
    151     *
    152     * @param keyBytes
    153     *            plaintext string to hash.
    154     * @param salt
    155     *            salt string including the prefix and optionally garbage at the end. The salt may be null, in which
    156     *            case a salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
    157     *            {@link SecureRandom} to generate your own salts.
    158     * @return the hash value
    159     * @throws IllegalArgumentException
    160     *             if the salt does not match the allowed pattern
    161     * @throws IllegalArgumentException
    162     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    163     */
    164    public static String apr1Crypt(final String keyBytes, final String salt) {
    165        return apr1Crypt(keyBytes.getBytes(StandardCharsets.UTF_8), salt);
    166    }
    167
    168    /**
    169     * Generates a libc6 crypt() compatible "$1$" hash value.
    170     * <p>
    171     * See {@link #md5Crypt(byte[], String)} for details.
    172     * </p>
    173     * <p>
    174     * A salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
    175     * {@link SecureRandom} to generate your own salts and calling {@link #md5Crypt(byte[], String)}.
    176     * </p>
    177     * @param keyBytes
    178     *            plaintext string to hash.
    179     * @return the hash value
    180     * @throws IllegalArgumentException
    181     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    182     * @see #md5Crypt(byte[], String)
    183     */
    184    public static String md5Crypt(final byte[] keyBytes) {
    185        return md5Crypt(keyBytes, MD5_PREFIX + B64.getRandomSalt(8));
    186    }
    187
    188    /**
    189     * Generates a libc6 crypt() compatible "$1$" hash value.
    190     * <p>
    191     * See {@link #md5Crypt(byte[], String)} for details.
    192     * </p>
    193     * <p>
    194     * A salt is generated for you using the instance of {@link Random} you supply.
    195     * </p>
    196     * @param keyBytes
    197     *            plaintext string to hash.
    198     * @param random
    199     *            the instance of {@link Random} to use for generating the salt. Consider using {@link SecureRandom}
    200     *            or {@link ThreadLocalRandom}.
    201     * @return the hash value
    202     * @throws IllegalArgumentException
    203     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    204     * @see #md5Crypt(byte[], String)
    205     * @since 1.12
    206     */
    207    public static String md5Crypt(final byte[] keyBytes, final Random random) {
    208        return md5Crypt(keyBytes, MD5_PREFIX + B64.getRandomSalt(8, random));
    209    }
    210
    211    /**
    212     * Generates a libc crypt() compatible "$1$" MD5 based hash value.
    213     * <p>
    214     * See {@link Crypt#crypt(String, String)} for details. We use {@link SecureRandom} for seed generation by
    215     * default.
    216     * </p>
    217     *
    218     * @param keyBytes
    219     *            plaintext string to hash.
    220     * @param salt
    221     *            salt string including the prefix and optionally garbage at the end. The salt may be null, in which
    222     *            case a salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
    223     *            {@link SecureRandom} to generate your own salts.
    224     * @return the hash value
    225     * @throws IllegalArgumentException
    226     *             if the salt does not match the allowed pattern
    227     * @throws IllegalArgumentException
    228     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    229     */
    230    public static String md5Crypt(final byte[] keyBytes, final String salt) {
    231        return md5Crypt(keyBytes, salt, MD5_PREFIX);
    232    }
    233
    234    /**
    235     * Generates a libc6 crypt() "$1$" or Apache htpasswd "$apr1$" hash value.
    236     * <p>
    237     * See {@link Crypt#crypt(String, String)} or {@link #apr1Crypt(String, String)} for details. We use
    238     * {@link SecureRandom by default}.
    239     * </p>
    240     *
    241     * @param keyBytes
    242     *            plaintext string to hash.
    243     * @param salt
    244     *            real salt value without prefix or "rounds=". The salt may be null, in which case a salt
    245     *            is generated for you using {@link ThreadLocalRandom}; for more secure salts consider
    246     *            using {@link SecureRandom} to generate your own salts.
    247     * @param prefix
    248     *            salt prefix
    249     * @return the hash value
    250     * @throws IllegalArgumentException
    251     *             if the salt does not match the allowed pattern
    252     * @throws IllegalArgumentException
    253     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    254     */
    255    public static String md5Crypt(final byte[] keyBytes, final String salt, final String prefix) {
    256        return md5Crypt(keyBytes, salt, prefix, new SecureRandom());
    257    }
    258
    259    /**
    260     * Generates a libc6 crypt() "$1$" or Apache htpasswd "$apr1$" hash value.
    261     * <p>
    262     * See {@link Crypt#crypt(String, String)} or {@link #apr1Crypt(String, String)} for details.
    263     * </p>
    264     *
    265     * @param keyBytes
    266     *            plaintext string to hash.
    267     * @param salt
    268     *            real salt value without prefix or "rounds=". The salt may be null, in which case a salt
    269     *            is generated for you using {@link ThreadLocalRandom}; for more secure salts consider
    270     *            using {@link SecureRandom} to generate your own salts.
    271     * @param prefix
    272     *            salt prefix
    273     * @param random
    274     *            the instance of {@link Random} to use for generating the salt. Consider using {@link SecureRandom}
    275     *            or {@link ThreadLocalRandom}.
    276     * @return the hash value
    277     * @throws IllegalArgumentException
    278     *             if the salt does not match the allowed pattern
    279     * @throws IllegalArgumentException
    280     *             when a {@link java.security.NoSuchAlgorithmException} is caught.
    281     * @since 1.12
    282     */
    283    public static String md5Crypt(final byte[] keyBytes, final String salt, final String prefix, final Random random) {
    284        final int keyLen = keyBytes.length;
    285
    286        // Extract the real salt from the given string which can be a complete hash string.
    287        final String saltString;
    288        if (salt == null) {
    289            saltString = B64.getRandomSalt(8, random);
    290        } else {
    291            final Pattern p = Pattern.compile("^" + prefix.replace("$", "\\$") + "([\\.\\/a-zA-Z0-9]{1,8}).*");
    292            final Matcher m = p.matcher(salt);
    293            if (!m.find()) {
    294                throw new IllegalArgumentException("Invalid salt value: " + salt);
    295            }
    296            saltString = m.group(1);
    297        }
    298        final byte[] saltBytes = saltString.getBytes(StandardCharsets.UTF_8);
    299
    300        final MessageDigest ctx = DigestUtils.getMd5Digest();
    301
    302        /*
    303         * The password first, since that is what is most unknown
    304         */
    305        ctx.update(keyBytes);
    306
    307        /*
    308         * Then our magic string
    309         */
    310        ctx.update(prefix.getBytes(StandardCharsets.UTF_8));
    311
    312        /*
    313         * Then the raw salt
    314         */
    315        ctx.update(saltBytes);
    316
    317        /*
    318         * Then just as many characters of the MD5(pw,salt,pw)
    319         */
    320        MessageDigest ctx1 = DigestUtils.getMd5Digest();
    321        ctx1.update(keyBytes);
    322        ctx1.update(saltBytes);
    323        ctx1.update(keyBytes);
    324        byte[] finalb = ctx1.digest();
    325        int ii = keyLen;
    326        while (ii > 0) {
    327            ctx.update(finalb, 0, Math.min(ii, 16));
    328            ii -= 16;
    329        }
    330
    331        /*
    332         * Don't leave anything around in vm they could use.
    333         */
    334        Arrays.fill(finalb, (byte) 0);
    335
    336        /*
    337         * Then something really weird...
    338         */
    339        ii = keyLen;
    340        final int j = 0;
    341        while (ii > 0) {
    342            if ((ii & 1) == 1) {
    343                ctx.update(finalb[j]);
    344            } else {
    345                ctx.update(keyBytes[j]);
    346            }
    347            ii >>= 1;
    348        }
    349
    350        /*
    351         * Now make the output string
    352         */
    353        final StringBuilder passwd = new StringBuilder(prefix + saltString + "$");
    354        finalb = ctx.digest();
    355
    356        /*
    357         * and now, just to make sure things don't run too fast On a 60 Mhz Pentium this takes 34 milliseconds, so you
    358         * would need 30 seconds to build a 1000 entry dictionary...
    359         */
    360        for (int i = 0; i < ROUNDS; i++) {
    361            ctx1 = DigestUtils.getMd5Digest();
    362            if ((i & 1) != 0) {
    363                ctx1.update(keyBytes);
    364            } else {
    365                ctx1.update(finalb, 0, BLOCKSIZE);
    366            }
    367
    368            if (i % 3 != 0) {
    369                ctx1.update(saltBytes);
    370            }
    371
    372            if (i % 7 != 0) {
    373                ctx1.update(keyBytes);
    374            }
    375
    376            if ((i & 1) != 0) {
    377                ctx1.update(finalb, 0, BLOCKSIZE);
    378            } else {
    379                ctx1.update(keyBytes);
    380            }
    381            finalb = ctx1.digest();
    382        }
    383
    384        // The following was nearly identical to the Sha2Crypt code.
    385        // Again, the buflen is not really needed.
    386        // int buflen = MD5_PREFIX.length() - 1 + salt_string.length() + 1 + BLOCKSIZE + 1;
    387        B64.b64from24bit(finalb[0], finalb[6], finalb[12], 4, passwd);
    388        B64.b64from24bit(finalb[1], finalb[7], finalb[13], 4, passwd);
    389        B64.b64from24bit(finalb[2], finalb[8], finalb[14], 4, passwd);
    390        B64.b64from24bit(finalb[3], finalb[9], finalb[15], 4, passwd);
    391        B64.b64from24bit(finalb[4], finalb[10], finalb[5], 4, passwd);
    392        B64.b64from24bit((byte) 0, (byte) 0, finalb[11], 2, passwd);
    393
    394        /*
    395         * Don't leave anything around in vm they could use.
    396         */
    397        // Is there a better way to do this with the JVM?
    398        ctx.reset();
    399        ctx1.reset();
    400        Arrays.fill(keyBytes, (byte) 0);
    401        Arrays.fill(saltBytes, (byte) 0);
    402        Arrays.fill(finalb, (byte) 0);
    403
    404        return passwd.toString();
    405    }
    406}