1 /*
2 * Copyright (c) 2002, 2013, 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
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 abstract 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 int[] W;
68
69 // state of this object
70 private int[] state;
71
72 // initial state value. different between SHA-224 and SHA-256
73 private final int[] initialHashes;
74
75 /**
76 * Creates a new SHA object.
77 */
78 SHA2(String name, int digestLength, int[] initialHashes) {
79 super(name, digestLength, 64);
80 this.initialHashes = initialHashes;
81 state = new int[8];
82 W = new int[64];
83 implReset();
84 }
85
86 /**
87 * Resets the buffers and hash value to start a new hash.
88 */
89 void implReset() {
90 System.arraycopy(initialHashes, 0, state, 0, state.length);
91 }
92
93 void implDigest(byte[] out, int ofs) {
94 long bitsProcessed = bytesProcessed << 3;
95
96 int index = (int)bytesProcessed & 0x3f;
97 int padLen = (index < 56) ? (56 - index) : (120 - index);
98 engineUpdate(padding, 0, padLen);
99
100 i2bBig4((int)(bitsProcessed >>> 32), buffer, 56);
101 i2bBig4((int)bitsProcessed, buffer, 60);
102 implCompress(buffer, 0);
103
104 i2bBig(state, 0, out, ofs, engineGetDigestLength());
105 }
106
107 /**
108 * logical function ch(x,y,z) as defined in spec:
109 * @return (x and y) xor ((complement x) and z)
110 * @param x int
111 * @param y int
112 * @param z int
113 */
114 private static int lf_ch(int x, int y, int z) {
115 return (x & y) ^ ((~x) & z);
116 }
117
118 /**
119 * logical function maj(x,y,z) as defined in spec:
120 * @return (x and y) xor (x and z) xor (y and z)
121 * @param x int
122 * @param y int
123 * @param z int
124 */
125 private static int lf_maj(int x, int y, int z) {
126 return (x & y) ^ (x & z) ^ (y & z);
127 }
128
129 /**
130 * logical function R(x,s) - right shift
131 * @return x right shift for s times
132 * @param x int
133 * @param s int
134 */
135 private static int lf_R( int x, int s ) {
136 return (x >>> s);
137 }
138
139 /**
140 * logical function S(x,s) - right rotation
141 * @return x circular right shift for s times
142 * @param x int
143 * @param s int
144 */
145 private static int lf_S(int x, int s) {
146 return (x >>> s) | (x << (32 - s));
147 }
148
149 /**
150 * logical function sigma0(x) - xor of results of right rotations
151 * @return S(x,2) xor S(x,13) xor S(x,22)
152 * @param x int
153 */
154 private static int lf_sigma0(int x) {
155 return lf_S(x, 2) ^ lf_S(x, 13) ^ lf_S(x, 22);
156 }
157
158 /**
159 * logical function sigma1(x) - xor of results of right rotations
160 * @return S(x,6) xor S(x,11) xor S(x,25)
161 * @param x int
162 */
163 private static int lf_sigma1(int x) {
164 return lf_S( x, 6 ) ^ lf_S( x, 11 ) ^ lf_S( x, 25 );
165 }
166
167 /**
168 * logical function delta0(x) - xor of results of right shifts/rotations
169 * @return int
170 * @param x int
171 */
172 private static int lf_delta0(int x) {
173 return lf_S(x, 7) ^ lf_S(x, 18) ^ lf_R(x, 3);
174 }
175
176 /**
177 * logical function delta1(x) - xor of results of right shifts/rotations
178 * @return int
179 * @param x int
180 */
181 private static int lf_delta1(int x) {
182 return lf_S(x, 17) ^ lf_S(x, 19) ^ lf_R(x, 10);
183 }
184
185 /**
186 * Process the current block to update the state variable state.
187 */
188 void implCompress(byte[] buf, int ofs) {
189 b2iBig64(buf, ofs, W);
190
191 // The first 16 ints are from the byte stream, compute the rest of
192 // the W[]'s
193 for (int t = 16; t < ITERATION; t++) {
194 W[t] = lf_delta1(W[t-2]) + W[t-7] + lf_delta0(W[t-15])
195 + W[t-16];
196 }
197
198 int a = state[0];
199 int b = state[1];
200 int c = state[2];
201 int d = state[3];
202 int e = state[4];
203 int f = state[5];
204 int g = state[6];
205 int h = state[7];
206
207 for (int i = 0; i < ITERATION; i++) {
208 int T1 = h + lf_sigma1(e) + lf_ch(e,f,g) + ROUND_CONSTS[i] + W[i];
209 int T2 = lf_sigma0(a) + lf_maj(a,b,c);
210 h = g;
211 g = f;
212 f = e;
213 e = d + T1;
214 d = c;
215 c = b;
216 b = a;
217 a = T1 + T2;
218 }
219 state[0] += a;
220 state[1] += b;
221 state[2] += c;
222 state[3] += d;
223 state[4] += e;
224 state[5] += f;
225 state[6] += g;
226 state[7] += h;
227 }
228
229 public Object clone() throws CloneNotSupportedException {
230 SHA2 copy = (SHA2) super.clone();
231 copy.state = copy.state.clone();
232 copy.W = new int[64];
233 return copy;
234 }
235
236 /**
237 * SHA-224 implementation class.
238 */
239 public static final class SHA224 extends SHA2 {
240 private static final int[] INITIAL_HASHES = {
241 0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
242 0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4
243 };
244
245 public SHA224() {
246 super("SHA-224", 28, INITIAL_HASHES);
247 }
248 }
249
250 /**
251 * SHA-256 implementation class.
252 */
253 public static final class SHA256 extends SHA2 {
254 private static final int[] INITIAL_HASHES = {
255 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
256 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
257 };
258
259 public SHA256() {
260 super("SHA-256", 32, INITIAL_HASHES);
261 }
262 }
263 }