J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2002-2006 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 static sun.security.provider.ByteArrayAccess.*; |
| 29 | |
| 30 | /** |
| 31 | * This class implements the Secure Hash Algorithm SHA-256 developed by |
| 32 | * the National Institute of Standards and Technology along with the |
| 33 | * National Security Agency. |
| 34 | * |
| 35 | * <p>It implements java.security.MessageDigestSpi, and can be used |
| 36 | * through Java Cryptography Architecture (JCA), as a pluggable |
| 37 | * MessageDigest implementation. |
| 38 | * |
| 39 | * @since 1.4.2 |
| 40 | * @author Valerie Peng |
| 41 | * @author Andreas Sterbenz |
| 42 | */ |
| 43 | public final class SHA2 extends DigestBase { |
| 44 | |
| 45 | private static final int ITERATION = 64; |
| 46 | // Constants for each round |
| 47 | private static final int[] ROUND_CONSTS = { |
| 48 | 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, |
| 49 | 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, |
| 50 | 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, |
| 51 | 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, |
| 52 | 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, |
| 53 | 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, |
| 54 | 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, |
| 55 | 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, |
| 56 | 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, |
| 57 | 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, |
| 58 | 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, |
| 59 | 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, |
| 60 | 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, |
| 61 | 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, |
| 62 | 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, |
| 63 | 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 |
| 64 | }; |
| 65 | |
| 66 | // buffer used by implCompress() |
| 67 | private final int[] W; |
| 68 | |
| 69 | // state of this object |
| 70 | private final int[] state; |
| 71 | |
| 72 | /** |
| 73 | * Creates a new SHA object. |
| 74 | */ |
| 75 | public SHA2() { |
| 76 | super("SHA-256", 32, 64); |
| 77 | state = new int[8]; |
| 78 | W = new int[64]; |
| 79 | implReset(); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Creates a SHA2 object.with state (for cloning) |
| 84 | */ |
| 85 | private SHA2(SHA2 base) { |
| 86 | super(base); |
| 87 | this.state = base.state.clone(); |
| 88 | this.W = new int[64]; |
| 89 | } |
| 90 | |
| 91 | public Object clone() { |
| 92 | return new SHA2(this); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Resets the buffers and hash value to start a new hash. |
| 97 | */ |
| 98 | void implReset() { |
| 99 | state[0] = 0x6a09e667; |
| 100 | state[1] = 0xbb67ae85; |
| 101 | state[2] = 0x3c6ef372; |
| 102 | state[3] = 0xa54ff53a; |
| 103 | state[4] = 0x510e527f; |
| 104 | state[5] = 0x9b05688c; |
| 105 | state[6] = 0x1f83d9ab; |
| 106 | state[7] = 0x5be0cd19; |
| 107 | } |
| 108 | |
| 109 | void implDigest(byte[] out, int ofs) { |
| 110 | long bitsProcessed = bytesProcessed << 3; |
| 111 | |
| 112 | int index = (int)bytesProcessed & 0x3f; |
| 113 | int padLen = (index < 56) ? (56 - index) : (120 - index); |
| 114 | engineUpdate(padding, 0, padLen); |
| 115 | |
| 116 | i2bBig4((int)(bitsProcessed >>> 32), buffer, 56); |
| 117 | i2bBig4((int)bitsProcessed, buffer, 60); |
| 118 | implCompress(buffer, 0); |
| 119 | |
| 120 | i2bBig(state, 0, out, ofs, 32); |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * logical function ch(x,y,z) as defined in spec: |
| 125 | * @return (x and y) xor ((complement x) and z) |
| 126 | * @param x int |
| 127 | * @param y int |
| 128 | * @param z int |
| 129 | */ |
| 130 | private static int lf_ch(int x, int y, int z) { |
| 131 | return (x & y) ^ ((~x) & z); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * logical function maj(x,y,z) as defined in spec: |
| 136 | * @return (x and y) xor (x and z) xor (y and z) |
| 137 | * @param x int |
| 138 | * @param y int |
| 139 | * @param z int |
| 140 | */ |
| 141 | private static int lf_maj(int x, int y, int z) { |
| 142 | return (x & y) ^ (x & z) ^ (y & z); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * logical function R(x,s) - right shift |
| 147 | * @return x right shift for s times |
| 148 | * @param x int |
| 149 | * @param s int |
| 150 | */ |
| 151 | private static int lf_R( int x, int s ) { |
| 152 | return (x >>> s); |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * logical function S(x,s) - right rotation |
| 157 | * @return x circular right shift for s times |
| 158 | * @param x int |
| 159 | * @param s int |
| 160 | */ |
| 161 | private static int lf_S(int x, int s) { |
| 162 | return (x >>> s) | (x << (32 - s)); |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * logical function sigma0(x) - xor of results of right rotations |
| 167 | * @return S(x,2) xor S(x,13) xor S(x,22) |
| 168 | * @param x int |
| 169 | */ |
| 170 | private static int lf_sigma0(int x) { |
| 171 | return lf_S(x, 2) ^ lf_S(x, 13) ^ lf_S(x, 22); |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * logical function sigma1(x) - xor of results of right rotations |
| 176 | * @return S(x,6) xor S(x,11) xor S(x,25) |
| 177 | * @param x int |
| 178 | */ |
| 179 | private static int lf_sigma1(int x) { |
| 180 | return lf_S( x, 6 ) ^ lf_S( x, 11 ) ^ lf_S( x, 25 ); |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * logical function delta0(x) - xor of results of right shifts/rotations |
| 185 | * @return int |
| 186 | * @param x int |
| 187 | */ |
| 188 | private static int lf_delta0(int x) { |
| 189 | return lf_S(x, 7) ^ lf_S(x, 18) ^ lf_R(x, 3); |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * logical function delta1(x) - xor of results of right shifts/rotations |
| 194 | * @return int |
| 195 | * @param x int |
| 196 | */ |
| 197 | private static int lf_delta1(int x) { |
| 198 | return lf_S(x, 17) ^ lf_S(x, 19) ^ lf_R(x, 10); |
| 199 | } |
| 200 | |
| 201 | /** |
| 202 | * Process the current block to update the state variable state. |
| 203 | */ |
| 204 | void implCompress(byte[] buf, int ofs) { |
| 205 | b2iBig64(buf, ofs, W); |
| 206 | |
| 207 | // The first 16 ints are from the byte stream, compute the rest of |
| 208 | // the W[]'s |
| 209 | for (int t = 16; t < ITERATION; t++) { |
| 210 | W[t] = lf_delta1(W[t-2]) + W[t-7] + lf_delta0(W[t-15]) |
| 211 | + W[t-16]; |
| 212 | } |
| 213 | |
| 214 | int a = state[0]; |
| 215 | int b = state[1]; |
| 216 | int c = state[2]; |
| 217 | int d = state[3]; |
| 218 | int e = state[4]; |
| 219 | int f = state[5]; |
| 220 | int g = state[6]; |
| 221 | int h = state[7]; |
| 222 | |
| 223 | for (int i = 0; i < ITERATION; i++) { |
| 224 | int T1 = h + lf_sigma1(e) + lf_ch(e,f,g) + ROUND_CONSTS[i] + W[i]; |
| 225 | int T2 = lf_sigma0(a) + lf_maj(a,b,c); |
| 226 | h = g; |
| 227 | g = f; |
| 228 | f = e; |
| 229 | e = d + T1; |
| 230 | d = c; |
| 231 | c = b; |
| 232 | b = a; |
| 233 | a = T1 + T2; |
| 234 | } |
| 235 | state[0] += a; |
| 236 | state[1] += b; |
| 237 | state[2] += c; |
| 238 | state[3] += d; |
| 239 | state[4] += e; |
| 240 | state[5] += f; |
| 241 | state[6] += g; |
| 242 | state[7] += h; |
| 243 | } |
| 244 | |
| 245 | } |