MD4.java revision 12745:f068a4ffddd2 
1/*
2 * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package sun.security.provider;
27
28import java.security.*;
29
30import static sun.security.provider.ByteArrayAccess.*;
31
32/**
33 * The MD4 class is used to compute an MD4 message digest over a given
34 * buffer of bytes. It is an implementation of the RSA Data Security Inc
35 * MD4 algorithim as described in internet RFC 1320.
36 *
37 * <p>The MD4 algorithm is very weak and should not be used unless it is
38 * unavoidable. Therefore, it is not registered in our standard providers. To
39 * obtain an implementation, call the static getInstance() method in this
40 * class.
41 *
42 * @author      Andreas Sterbenz
43 */
44public final class MD4 extends DigestBase {
45
46    // state of this object
47    private int[] state;
48    // temporary buffer, used by implCompress()
49    private int[] x;
50
51    // rotation constants
52    private static final int S11 = 3;
53    private static final int S12 = 7;
54    private static final int S13 = 11;
55    private static final int S14 = 19;
56    private static final int S21 = 3;
57    private static final int S22 = 5;
58    private static final int S23 = 9;
59    private static final int S24 = 13;
60    private static final int S31 = 3;
61    private static final int S32 = 9;
62    private static final int S33 = 11;
63    private static final int S34 = 15;
64
65    private static final Provider md4Provider;
66
67    static {
68        md4Provider = new Provider("MD4Provider", 1.9d, "MD4 MessageDigest") {
69            private static final long serialVersionUID = -8850464997518327965L;
70        };
71        AccessController.doPrivileged(new PrivilegedAction<Void>() {
72            public Void run() {
73                md4Provider.put("MessageDigest.MD4", "sun.security.provider.MD4");
74                return null;
75            }
76        });
77    }
78
79    public static MessageDigest getInstance() {
80        try {
81            return MessageDigest.getInstance("MD4", md4Provider);
82        } catch (NoSuchAlgorithmException e) {
83            // should never occur
84            throw new ProviderException(e);
85        }
86    }
87
88    // Standard constructor, creates a new MD4 instance.
89    public MD4() {
90        super("MD4", 16, 64);
91        state = new int[4];
92        x = new int[16];
93        implReset();
94    }
95
96    // clone this object
97    public Object clone() throws CloneNotSupportedException {
98        MD4 copy = (MD4) super.clone();
99        copy.state = copy.state.clone();
100        copy.x = new int[16];
101        return copy;
102    }
103
104    /**
105     * Reset the state of this object.
106     */
107    void implReset() {
108        // Load magic initialization constants.
109        state[0] = 0x67452301;
110        state[1] = 0xefcdab89;
111        state[2] = 0x98badcfe;
112        state[3] = 0x10325476;
113    }
114
115    /**
116     * Perform the final computations, any buffered bytes are added
117     * to the digest, the count is added to the digest, and the resulting
118     * digest is stored.
119     */
120    void implDigest(byte[] out, int ofs) {
121        long bitsProcessed = bytesProcessed << 3;
122
123        int index = (int)bytesProcessed & 0x3f;
124        int padLen = (index < 56) ? (56 - index) : (120 - index);
125        engineUpdate(padding, 0, padLen);
126
127        i2bLittle4((int)bitsProcessed, buffer, 56);
128        i2bLittle4((int)(bitsProcessed >>> 32), buffer, 60);
129        implCompress(buffer, 0);
130
131        i2bLittle(state, 0, out, ofs, 16);
132    }
133
134    private static int FF(int a, int b, int c, int d, int x, int s) {
135        a += ((b & c) | ((~b) & d)) + x;
136        return ((a << s) | (a >>> (32 - s)));
137    }
138
139    private static int GG(int a, int b, int c, int d, int x, int s) {
140        a += ((b & c) | (b & d) | (c & d)) + x + 0x5a827999;
141        return ((a << s) | (a >>> (32 - s)));
142    }
143
144    private static int HH(int a, int b, int c, int d, int x, int s) {
145        a += ((b ^ c) ^ d) + x + 0x6ed9eba1;
146        return ((a << s) | (a >>> (32 - s)));
147    }
148
149    /**
150     * This is where the functions come together as the generic MD4
151     * transformation operation. It consumes sixteen
152     * bytes from the buffer, beginning at the specified offset.
153     */
154    void implCompress(byte[] buf, int ofs) {
155        b2iLittle64(buf, ofs, x);
156
157        int a = state[0];
158        int b = state[1];
159        int c = state[2];
160        int d = state[3];
161
162        /* Round 1 */
163        a = FF (a, b, c, d, x[ 0], S11); /* 1 */
164        d = FF (d, a, b, c, x[ 1], S12); /* 2 */
165        c = FF (c, d, a, b, x[ 2], S13); /* 3 */
166        b = FF (b, c, d, a, x[ 3], S14); /* 4 */
167        a = FF (a, b, c, d, x[ 4], S11); /* 5 */
168        d = FF (d, a, b, c, x[ 5], S12); /* 6 */
169        c = FF (c, d, a, b, x[ 6], S13); /* 7 */
170        b = FF (b, c, d, a, x[ 7], S14); /* 8 */
171        a = FF (a, b, c, d, x[ 8], S11); /* 9 */
172        d = FF (d, a, b, c, x[ 9], S12); /* 10 */
173        c = FF (c, d, a, b, x[10], S13); /* 11 */
174        b = FF (b, c, d, a, x[11], S14); /* 12 */
175        a = FF (a, b, c, d, x[12], S11); /* 13 */
176        d = FF (d, a, b, c, x[13], S12); /* 14 */
177        c = FF (c, d, a, b, x[14], S13); /* 15 */
178        b = FF (b, c, d, a, x[15], S14); /* 16 */
179
180        /* Round 2 */
181        a = GG (a, b, c, d, x[ 0], S21); /* 17 */
182        d = GG (d, a, b, c, x[ 4], S22); /* 18 */
183        c = GG (c, d, a, b, x[ 8], S23); /* 19 */
184        b = GG (b, c, d, a, x[12], S24); /* 20 */
185        a = GG (a, b, c, d, x[ 1], S21); /* 21 */
186        d = GG (d, a, b, c, x[ 5], S22); /* 22 */
187        c = GG (c, d, a, b, x[ 9], S23); /* 23 */
188        b = GG (b, c, d, a, x[13], S24); /* 24 */
189        a = GG (a, b, c, d, x[ 2], S21); /* 25 */
190        d = GG (d, a, b, c, x[ 6], S22); /* 26 */
191        c = GG (c, d, a, b, x[10], S23); /* 27 */
192        b = GG (b, c, d, a, x[14], S24); /* 28 */
193        a = GG (a, b, c, d, x[ 3], S21); /* 29 */
194        d = GG (d, a, b, c, x[ 7], S22); /* 30 */
195        c = GG (c, d, a, b, x[11], S23); /* 31 */
196        b = GG (b, c, d, a, x[15], S24); /* 32 */
197
198        /* Round 3 */
199        a = HH (a, b, c, d, x[ 0], S31); /* 33 */
200        d = HH (d, a, b, c, x[ 8], S32); /* 34 */
201        c = HH (c, d, a, b, x[ 4], S33); /* 35 */
202        b = HH (b, c, d, a, x[12], S34); /* 36 */
203        a = HH (a, b, c, d, x[ 2], S31); /* 37 */
204        d = HH (d, a, b, c, x[10], S32); /* 38 */
205        c = HH (c, d, a, b, x[ 6], S33); /* 39 */
206        b = HH (b, c, d, a, x[14], S34); /* 40 */
207        a = HH (a, b, c, d, x[ 1], S31); /* 41 */
208        d = HH (d, a, b, c, x[ 9], S32); /* 42 */
209        c = HH (c, d, a, b, x[ 5], S33); /* 43 */
210        b = HH (b, c, d, a, x[13], S34); /* 44 */
211        a = HH (a, b, c, d, x[ 3], S31); /* 45 */
212        d = HH (d, a, b, c, x[11], S32); /* 46 */
213        c = HH (c, d, a, b, x[ 7], S33); /* 47 */
214        b = HH (b, c, d, a, x[15], S34); /* 48 */
215
216        state[0] += a;
217        state[1] += b;
218        state[2] += c;
219        state[3] += d;
220    }
221
222}
223