J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.security.provider; |
| 27 | |
| 28 | import java.util.Arrays; |
| 29 | |
| 30 | /** |
| 31 | * Implementation for the MD2 algorithm, see RFC1319. It is very slow and |
| 32 | * not particular secure. It is only supported to be able to verify |
| 33 | * RSA/Verisign root certificates signed using MD2withRSA. It should not |
| 34 | * be used for anything else. |
| 35 | * |
| 36 | * @since 1.5 |
| 37 | * @author Andreas Sterbenz |
| 38 | */ |
| 39 | public final class MD2 extends DigestBase { |
| 40 | |
| 41 | // state, 48 ints |
| 42 | private final int[] X; |
| 43 | |
| 44 | // checksum, 16 ints. they are really bytes, but byte arithmetic in |
| 45 | // the JVM is much slower that int arithmetic. |
| 46 | private final int[] C; |
| 47 | |
| 48 | // temporary store for checksum C during final digest |
| 49 | private final byte[] cBytes; |
| 50 | |
| 51 | /** |
| 52 | * Create a new MD2 digest. Called by the JCA framework |
| 53 | */ |
| 54 | public MD2() { |
| 55 | super("MD2", 16, 16); |
| 56 | X = new int[48]; |
| 57 | C = new int[16]; |
| 58 | cBytes = new byte[16]; |
| 59 | } |
| 60 | |
| 61 | private MD2(MD2 base) { |
| 62 | super(base); |
| 63 | this.X = base.X.clone(); |
| 64 | this.C = base.C.clone(); |
| 65 | cBytes = new byte[16]; |
| 66 | } |
| 67 | |
| 68 | public Object clone() { |
| 69 | return new MD2(this); |
| 70 | } |
| 71 | |
| 72 | // reset state and checksum |
| 73 | void implReset() { |
| 74 | Arrays.fill(X, 0); |
| 75 | Arrays.fill(C, 0); |
| 76 | } |
| 77 | |
| 78 | // finish the digest |
| 79 | void implDigest(byte[] out, int ofs) { |
| 80 | int padValue = 16 - ((int)bytesProcessed & 15); |
| 81 | engineUpdate(PADDING[padValue], 0, padValue); |
| 82 | for (int i = 0; i < 16; i++) { |
| 83 | cBytes[i] = (byte)C[i]; |
| 84 | } |
| 85 | implCompress(cBytes, 0); |
| 86 | for (int i = 0; i < 16; i++) { |
| 87 | out[ofs + i] = (byte)X[i]; |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | // one iteration of the compression function |
| 92 | void implCompress(byte[] b, int ofs) { |
| 93 | for (int i = 0; i < 16; i++) { |
| 94 | int k = b[ofs + i] & 0xff; |
| 95 | X[16 + i] = k; |
| 96 | X[32 + i] = k ^ X[i]; |
| 97 | } |
| 98 | |
| 99 | // update the checksum |
| 100 | int t = C[15]; |
| 101 | for (int i = 0; i < 16; i++) { |
| 102 | t = (C[i] ^= S[X[16 + i] ^ t]); |
| 103 | } |
| 104 | |
| 105 | t = 0; |
| 106 | for (int i = 0; i < 18; i++) { |
| 107 | for (int j = 0; j < 48; j++) { |
| 108 | t = (X[j] ^= S[t]); |
| 109 | } |
| 110 | t = (t + i) & 0xff; |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | // substitution table derived from Pi. Copied from the RFC. |
| 115 | private final static int[] S = new int[] { |
| 116 | 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, |
| 117 | 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, |
| 118 | 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, |
| 119 | 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, |
| 120 | 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, |
| 121 | 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, |
| 122 | 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, |
| 123 | 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, |
| 124 | 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157, |
| 125 | 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27, |
| 126 | 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15, |
| 127 | 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197, |
| 128 | 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65, |
| 129 | 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123, |
| 130 | 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233, |
| 131 | 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228, |
| 132 | 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237, |
| 133 | 31, 26, 219, 153, 141, 51, 159, 17, 131, 20, |
| 134 | }; |
| 135 | |
| 136 | // digest padding. 17 element array. |
| 137 | // padding[0] is null |
| 138 | // padding[i] is an array of i time the byte value i (i = 1..16) |
| 139 | private final static byte[][] PADDING; |
| 140 | |
| 141 | static { |
| 142 | PADDING = new byte[17][]; |
| 143 | for (int i = 1; i < 17; i++) { |
| 144 | byte[] b = new byte[i]; |
| 145 | Arrays.fill(b, (byte)i); |
| 146 | PADDING[i] = b; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | } |