/*
* Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.provider;
import static sun.security.provider.ByteArrayAccess.*;
/**
* This class implements the Secure Hash Algorithm (SHA) developed by
* the National Institute of Standards and Technology along with the
* National Security Agency. This is the updated version of SHA
* fip-180 as superseded by fip-180-1.
*
* <p>It implement JavaSecurity MessageDigest, and can be used by in
* the Java Security framework, as a pluggable implementation, as a
* filter for the digest stream classes.
*
* @author Roger Riggs
* @author Benjamin Renaud
* @author Andreas Sterbenz
*/
public final class SHA extends DigestBase {
// Buffer of int's and count of characters accumulated
// 64 bytes are included in each hash block so the low order
// bits of count are used to know how to pack the bytes into ints
// and to know when to compute the block and start the next one.
private final int[] W;
// state of this
private final int[] state;
/**
* Creates a new SHA object.
*/
public SHA() {
super("SHA-1", 20, 64);
state = new int[5];
W = new int[80];
implReset();
}
/**
* Creates a SHA object.with state (for cloning) */
private SHA(SHA base) {
super(base);
this.state = base.state.clone();
this.W = new int[80];
}
/*
* Clones this object.
*/
public Object clone() {
return new SHA(this);
}
/**
* Resets the buffers and hash value to start a new hash.
*/
void implReset() {
state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;
state[4] = 0xc3d2e1f0;
}
/**
* Computes the final hash and copies the 20 bytes to the output array.
*/
void implDigest(byte[] out, int ofs) {
long bitsProcessed = bytesProcessed << 3;
int index = (int)bytesProcessed & 0x3f;
int padLen = (index < 56) ? (56 - index) : (120 - index);
engineUpdate(padding, 0, padLen);
i2bBig4((int)(bitsProcessed >>> 32), buffer, 56);
i2bBig4((int)bitsProcessed, buffer, 60);
implCompress(buffer, 0);
i2bBig(state, 0, out, ofs, 20);
}
// Constants for each round
private final static int round1_kt = 0x5a827999;
private final static int round2_kt = 0x6ed9eba1;
private final static int round3_kt = 0x8f1bbcdc;
private final static int round4_kt = 0xca62c1d6;
/**
* Compute a the hash for the current block.
*
* This is in the same vein as Peter Gutmann's algorithm listed in
* the back of Applied Cryptography, Compact implementation of
* "old" NIST Secure Hash Algorithm.
*/
void implCompress(byte[] buf, int ofs) {
b2iBig64(buf, ofs, W);
// The first 16 ints have the byte stream, compute the rest of
// the buffer
for (int t = 16; t <= 79; t++) {
int temp = W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16];
W[t] = (temp << 1) | (temp >>> 31);
}
int a = state[0];
int b = state[1];
int c = state[2];
int d = state[3];
int e = state[4];
// Round 1
for (int i = 0; i < 20; i++) {
int temp = ((a<<5) | (a>>>(32-5))) +
((b&c)|((~b)&d))+ e + W[i] + round1_kt;
e = d;
d = c;
c = ((b<<30) | (b>>>(32-30)));
b = a;
a = temp;
}
// Round 2
for (int i = 20; i < 40; i++) {
int temp = ((a<<5) | (a>>>(32-5))) +
(b ^ c ^ d) + e + W[i] + round2_kt;
e = d;
d = c;
c = ((b<<30) | (b>>>(32-30)));
b = a;
a = temp;
}
// Round 3
for (int i = 40; i < 60; i++) {
int temp = ((a<<5) | (a>>>(32-5))) +
((b&c)|(b&d)|(c&d)) + e + W[i] + round3_kt;
e = d;
d = c;
c = ((b<<30) | (b>>>(32-30)));
b = a;
a = temp;
}
// Round 4
for (int i = 60; i < 80; i++) {
int temp = ((a<<5) | (a>>>(32-5))) +
(b ^ c ^ d) + e + W[i] + round4_kt;
e = d;
d = c;
c = ((b<<30) | (b>>>(32-30)));
b = a;
a = temp;
}
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
state[4] += e;
}
}