MD5Digest.java revision a198e1ecc615e26a167d0f2dca9fa7e5fc62de10 
1package org.bouncycastle.crypto.digests;
2
3
4import org.bouncycastle.util.Memoable;
5
6/**
7 * implementation of MD5 as outlined in "Handbook of Applied Cryptography", pages 346 - 347.
8 */
9public class MD5Digest
10    extends GeneralDigest
11{
12    private static final int    DIGEST_LENGTH = 16;
13
14    private int     H1, H2, H3, H4;         // IV's
15
16    private int[]   X = new int[16];
17    private int     xOff;
18
19    /**
20     * Standard constructor
21     */
22    public MD5Digest()
23    {
24        reset();
25    }
26
27    /**
28     * Copy constructor.  This will copy the state of the provided
29     * message digest.
30     */
31    public MD5Digest(MD5Digest t)
32    {
33        super(t);
34
35        copyIn(t);
36    }
37
38    private void copyIn(MD5Digest t)
39    {
40        super.copyIn(t);
41
42        H1 = t.H1;
43        H2 = t.H2;
44        H3 = t.H3;
45        H4 = t.H4;
46
47        System.arraycopy(t.X, 0, X, 0, t.X.length);
48        xOff = t.xOff;
49    }
50
51    public String getAlgorithmName()
52    {
53        return "MD5";
54    }
55
56    public int getDigestSize()
57    {
58        return DIGEST_LENGTH;
59    }
60
61    protected void processWord(
62        byte[]  in,
63        int     inOff)
64    {
65        X[xOff++] = (in[inOff] & 0xff) | ((in[inOff + 1] & 0xff) << 8)
66            | ((in[inOff + 2] & 0xff) << 16) | ((in[inOff + 3] & 0xff) << 24);
67
68        if (xOff == 16)
69        {
70            processBlock();
71        }
72    }
73
74    protected void processLength(
75        long    bitLength)
76    {
77        if (xOff > 14)
78        {
79            processBlock();
80        }
81
82        X[14] = (int)(bitLength & 0xffffffff);
83        X[15] = (int)(bitLength >>> 32);
84    }
85
86    private void unpackWord(
87        int     word,
88        byte[]  out,
89        int     outOff)
90    {
91        out[outOff]     = (byte)word;
92        out[outOff + 1] = (byte)(word >>> 8);
93        out[outOff + 2] = (byte)(word >>> 16);
94        out[outOff + 3] = (byte)(word >>> 24);
95    }
96
97    public int doFinal(
98        byte[]  out,
99        int     outOff)
100    {
101        finish();
102
103        unpackWord(H1, out, outOff);
104        unpackWord(H2, out, outOff + 4);
105        unpackWord(H3, out, outOff + 8);
106        unpackWord(H4, out, outOff + 12);
107
108        reset();
109
110        return DIGEST_LENGTH;
111    }
112
113    /**
114     * reset the chaining variables to the IV values.
115     */
116    public void reset()
117    {
118        super.reset();
119
120        H1 = 0x67452301;
121        H2 = 0xefcdab89;
122        H3 = 0x98badcfe;
123        H4 = 0x10325476;
124
125        xOff = 0;
126
127        for (int i = 0; i != X.length; i++)
128        {
129            X[i] = 0;
130        }
131    }
132
133    //
134    // round 1 left rotates
135    //
136    private static final int S11 = 7;
137    private static final int S12 = 12;
138    private static final int S13 = 17;
139    private static final int S14 = 22;
140
141    //
142    // round 2 left rotates
143    //
144    private static final int S21 = 5;
145    private static final int S22 = 9;
146    private static final int S23 = 14;
147    private static final int S24 = 20;
148
149    //
150    // round 3 left rotates
151    //
152    private static final int S31 = 4;
153    private static final int S32 = 11;
154    private static final int S33 = 16;
155    private static final int S34 = 23;
156
157    //
158    // round 4 left rotates
159    //
160    private static final int S41 = 6;
161    private static final int S42 = 10;
162    private static final int S43 = 15;
163    private static final int S44 = 21;
164
165    /*
166     * rotate int x left n bits.
167     */
168    private int rotateLeft(
169        int x,
170        int n)
171    {
172        return (x << n) | (x >>> (32 - n));
173    }
174
175    /*
176     * F, G, H and I are the basic MD5 functions.
177     */
178    private int F(
179        int u,
180        int v,
181        int w)
182    {
183        return (u & v) | (~u & w);
184    }
185
186    private int G(
187        int u,
188        int v,
189        int w)
190    {
191        return (u & w) | (v & ~w);
192    }
193
194    private int H(
195        int u,
196        int v,
197        int w)
198    {
199        return u ^ v ^ w;
200    }
201
202    private int K(
203        int u,
204        int v,
205        int w)
206    {
207        return v ^ (u | ~w);
208    }
209
210    protected void processBlock()
211    {
212        int a = H1;
213        int b = H2;
214        int c = H3;
215        int d = H4;
216
217        //
218        // Round 1 - F cycle, 16 times.
219        //
220        a = rotateLeft(a + F(b, c, d) + X[ 0] + 0xd76aa478, S11) + b;
221        d = rotateLeft(d + F(a, b, c) + X[ 1] + 0xe8c7b756, S12) + a;
222        c = rotateLeft(c + F(d, a, b) + X[ 2] + 0x242070db, S13) + d;
223        b = rotateLeft(b + F(c, d, a) + X[ 3] + 0xc1bdceee, S14) + c;
224        a = rotateLeft(a + F(b, c, d) + X[ 4] + 0xf57c0faf, S11) + b;
225        d = rotateLeft(d + F(a, b, c) + X[ 5] + 0x4787c62a, S12) + a;
226        c = rotateLeft(c + F(d, a, b) + X[ 6] + 0xa8304613, S13) + d;
227        b = rotateLeft(b + F(c, d, a) + X[ 7] + 0xfd469501, S14) + c;
228        a = rotateLeft(a + F(b, c, d) + X[ 8] + 0x698098d8, S11) + b;
229        d = rotateLeft(d + F(a, b, c) + X[ 9] + 0x8b44f7af, S12) + a;
230        c = rotateLeft(c + F(d, a, b) + X[10] + 0xffff5bb1, S13) + d;
231        b = rotateLeft(b + F(c, d, a) + X[11] + 0x895cd7be, S14) + c;
232        a = rotateLeft(a + F(b, c, d) + X[12] + 0x6b901122, S11) + b;
233        d = rotateLeft(d + F(a, b, c) + X[13] + 0xfd987193, S12) + a;
234        c = rotateLeft(c + F(d, a, b) + X[14] + 0xa679438e, S13) + d;
235        b = rotateLeft(b + F(c, d, a) + X[15] + 0x49b40821, S14) + c;
236
237        //
238        // Round 2 - G cycle, 16 times.
239        //
240        a = rotateLeft(a + G(b, c, d) + X[ 1] + 0xf61e2562, S21) + b;
241        d = rotateLeft(d + G(a, b, c) + X[ 6] + 0xc040b340, S22) + a;
242        c = rotateLeft(c + G(d, a, b) + X[11] + 0x265e5a51, S23) + d;
243        b = rotateLeft(b + G(c, d, a) + X[ 0] + 0xe9b6c7aa, S24) + c;
244        a = rotateLeft(a + G(b, c, d) + X[ 5] + 0xd62f105d, S21) + b;
245        d = rotateLeft(d + G(a, b, c) + X[10] + 0x02441453, S22) + a;
246        c = rotateLeft(c + G(d, a, b) + X[15] + 0xd8a1e681, S23) + d;
247        b = rotateLeft(b + G(c, d, a) + X[ 4] + 0xe7d3fbc8, S24) + c;
248        a = rotateLeft(a + G(b, c, d) + X[ 9] + 0x21e1cde6, S21) + b;
249        d = rotateLeft(d + G(a, b, c) + X[14] + 0xc33707d6, S22) + a;
250        c = rotateLeft(c + G(d, a, b) + X[ 3] + 0xf4d50d87, S23) + d;
251        b = rotateLeft(b + G(c, d, a) + X[ 8] + 0x455a14ed, S24) + c;
252        a = rotateLeft(a + G(b, c, d) + X[13] + 0xa9e3e905, S21) + b;
253        d = rotateLeft(d + G(a, b, c) + X[ 2] + 0xfcefa3f8, S22) + a;
254        c = rotateLeft(c + G(d, a, b) + X[ 7] + 0x676f02d9, S23) + d;
255        b = rotateLeft(b + G(c, d, a) + X[12] + 0x8d2a4c8a, S24) + c;
256
257        //
258        // Round 3 - H cycle, 16 times.
259        //
260        a = rotateLeft(a + H(b, c, d) + X[ 5] + 0xfffa3942, S31) + b;
261        d = rotateLeft(d + H(a, b, c) + X[ 8] + 0x8771f681, S32) + a;
262        c = rotateLeft(c + H(d, a, b) + X[11] + 0x6d9d6122, S33) + d;
263        b = rotateLeft(b + H(c, d, a) + X[14] + 0xfde5380c, S34) + c;
264        a = rotateLeft(a + H(b, c, d) + X[ 1] + 0xa4beea44, S31) + b;
265        d = rotateLeft(d + H(a, b, c) + X[ 4] + 0x4bdecfa9, S32) + a;
266        c = rotateLeft(c + H(d, a, b) + X[ 7] + 0xf6bb4b60, S33) + d;
267        b = rotateLeft(b + H(c, d, a) + X[10] + 0xbebfbc70, S34) + c;
268        a = rotateLeft(a + H(b, c, d) + X[13] + 0x289b7ec6, S31) + b;
269        d = rotateLeft(d + H(a, b, c) + X[ 0] + 0xeaa127fa, S32) + a;
270        c = rotateLeft(c + H(d, a, b) + X[ 3] + 0xd4ef3085, S33) + d;
271        b = rotateLeft(b + H(c, d, a) + X[ 6] + 0x04881d05, S34) + c;
272        a = rotateLeft(a + H(b, c, d) + X[ 9] + 0xd9d4d039, S31) + b;
273        d = rotateLeft(d + H(a, b, c) + X[12] + 0xe6db99e5, S32) + a;
274        c = rotateLeft(c + H(d, a, b) + X[15] + 0x1fa27cf8, S33) + d;
275        b = rotateLeft(b + H(c, d, a) + X[ 2] + 0xc4ac5665, S34) + c;
276
277        //
278        // Round 4 - K cycle, 16 times.
279        //
280        a = rotateLeft(a + K(b, c, d) + X[ 0] + 0xf4292244, S41) + b;
281        d = rotateLeft(d + K(a, b, c) + X[ 7] + 0x432aff97, S42) + a;
282        c = rotateLeft(c + K(d, a, b) + X[14] + 0xab9423a7, S43) + d;
283        b = rotateLeft(b + K(c, d, a) + X[ 5] + 0xfc93a039, S44) + c;
284        a = rotateLeft(a + K(b, c, d) + X[12] + 0x655b59c3, S41) + b;
285        d = rotateLeft(d + K(a, b, c) + X[ 3] + 0x8f0ccc92, S42) + a;
286        c = rotateLeft(c + K(d, a, b) + X[10] + 0xffeff47d, S43) + d;
287        b = rotateLeft(b + K(c, d, a) + X[ 1] + 0x85845dd1, S44) + c;
288        a = rotateLeft(a + K(b, c, d) + X[ 8] + 0x6fa87e4f, S41) + b;
289        d = rotateLeft(d + K(a, b, c) + X[15] + 0xfe2ce6e0, S42) + a;
290        c = rotateLeft(c + K(d, a, b) + X[ 6] + 0xa3014314, S43) + d;
291        b = rotateLeft(b + K(c, d, a) + X[13] + 0x4e0811a1, S44) + c;
292        a = rotateLeft(a + K(b, c, d) + X[ 4] + 0xf7537e82, S41) + b;
293        d = rotateLeft(d + K(a, b, c) + X[11] + 0xbd3af235, S42) + a;
294        c = rotateLeft(c + K(d, a, b) + X[ 2] + 0x2ad7d2bb, S43) + d;
295        b = rotateLeft(b + K(c, d, a) + X[ 9] + 0xeb86d391, S44) + c;
296
297        H1 += a;
298        H2 += b;
299        H3 += c;
300        H4 += d;
301
302        //
303        // reset the offset and clean out the word buffer.
304        //
305        xOff = 0;
306        for (int i = 0; i != X.length; i++)
307        {
308            X[i] = 0;
309        }
310    }
311
312    public Memoable copy()
313    {
314        return new MD5Digest(this);
315    }
316
317    public void reset(Memoable other)
318    {
319        MD5Digest d = (MD5Digest)other;
320
321        copyIn(d);
322    }
323}
324