/*
 * Copyright (c) 1996, 2012, 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 java.util.Arrays;

import static sun.security.provider.ByteArrayAccess.*;

The MD5 class is used to compute an MD5 message digest over a given buffer of bytes. It is an implementation of the RSA Data Security Inc MD5 algorithim as described in internet RFC 1321.
Author: Chuck McManis, Benjamin Renaud, Andreas Sterbenz
/** * The MD5 class is used to compute an MD5 message digest over a given * buffer of bytes. It is an implementation of the RSA Data Security Inc * MD5 algorithim as described in internet RFC 1321. * * @author Chuck McManis * @author Benjamin Renaud * @author Andreas Sterbenz */
public final class MD5 extends DigestBase { // state of this object private int[] state; // temporary buffer, used by implCompress() private int[] x; // rotation constants private static final int S11 = 7; private static final int S12 = 12; private static final int S13 = 17; private static final int S14 = 22; private static final int S21 = 5; private static final int S22 = 9; private static final int S23 = 14; private static final int S24 = 20; private static final int S31 = 4; private static final int S32 = 11; private static final int S33 = 16; private static final int S34 = 23; private static final int S41 = 6; private static final int S42 = 10; private static final int S43 = 15; private static final int S44 = 21; // Standard constructor, creates a new MD5 instance. public MD5() { super("MD5", 16, 64); state = new int[4]; x = new int[16]; resetHashes(); } // clone this object public Object clone() throws CloneNotSupportedException { MD5 copy = (MD5) super.clone(); copy.state = copy.state.clone(); copy.x = new int[16]; return copy; }
Reset the state of this object.
/** * Reset the state of this object. */
void implReset() { // Load magic initialization constants. resetHashes(); // clear out old data Arrays.fill(x, 0); } private void resetHashes() { state[0] = 0x67452301; state[1] = 0xefcdab89; state[2] = 0x98badcfe; state[3] = 0x10325476; }
Perform the final computations, any buffered bytes are added to the digest, the count is added to the digest, and the resulting digest is stored.
/** * Perform the final computations, any buffered bytes are added * to the digest, the count is added to the digest, and the resulting * digest is stored. */
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); i2bLittle4((int)bitsProcessed, buffer, 56); i2bLittle4((int)(bitsProcessed >>> 32), buffer, 60); implCompress(buffer, 0); i2bLittle(state, 0, out, ofs, 16); } /* ********************************************************** * The MD5 Functions. The results of this * implementation were checked against the RSADSI version. * ********************************************************** */ private static int FF(int a, int b, int c, int d, int x, int s, int ac) { a += ((b & c) | ((~b) & d)) + x + ac; return ((a << s) | (a >>> (32 - s))) + b; } private static int GG(int a, int b, int c, int d, int x, int s, int ac) { a += ((b & d) | (c & (~d))) + x + ac; return ((a << s) | (a >>> (32 - s))) + b; } private static int HH(int a, int b, int c, int d, int x, int s, int ac) { a += ((b ^ c) ^ d) + x + ac; return ((a << s) | (a >>> (32 - s))) + b; } private static int II(int a, int b, int c, int d, int x, int s, int ac) { a += (c ^ (b | (~d))) + x + ac; return ((a << s) | (a >>> (32 - s))) + b; }
This is where the functions come together as the generic MD5 transformation operation. It consumes sixteen bytes from the buffer, beginning at the specified offset.
/** * This is where the functions come together as the generic MD5 * transformation operation. It consumes sixteen * bytes from the buffer, beginning at the specified offset. */
void implCompress(byte[] buf, int ofs) { b2iLittle64(buf, ofs, x); int a = state[0]; int b = state[1]; int c = state[2]; int d = state[3]; /* Round 1 */ a = FF ( a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */ d = FF ( d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */ c = FF ( c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */ b = FF ( b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */ a = FF ( a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */ d = FF ( d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */ c = FF ( c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */ b = FF ( b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */ a = FF ( a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */ d = FF ( d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */ c = FF ( c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */ b = FF ( b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */ a = FF ( a, b, c, d, x[12], S11, 0x6b901122); /* 13 */ d = FF ( d, a, b, c, x[13], S12, 0xfd987193); /* 14 */ c = FF ( c, d, a, b, x[14], S13, 0xa679438e); /* 15 */ b = FF ( b, c, d, a, x[15], S14, 0x49b40821); /* 16 */ /* Round 2 */ a = GG ( a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */ d = GG ( d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */ c = GG ( c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */ b = GG ( b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */ a = GG ( a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */ d = GG ( d, a, b, c, x[10], S22, 0x2441453); /* 22 */ c = GG ( c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */ b = GG ( b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */ a = GG ( a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */ d = GG ( d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */ c = GG ( c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */ b = GG ( b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */ a = GG ( a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */ d = GG ( d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */ c = GG ( c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */ b = GG ( b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */ /* Round 3 */ a = HH ( a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */ d = HH ( d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */ c = HH ( c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */ b = HH ( b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */ a = HH ( a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */ d = HH ( d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */ c = HH ( c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */ b = HH ( b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */ a = HH ( a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */ d = HH ( d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */ c = HH ( c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */ b = HH ( b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */ a = HH ( a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */ d = HH ( d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */ c = HH ( c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */ b = HH ( b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */ /* Round 4 */ a = II ( a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */ d = II ( d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */ c = II ( c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */ b = II ( b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */ a = II ( a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */ d = II ( d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */ c = II ( c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */ b = II ( b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */ a = II ( a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */ d = II ( d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */ c = II ( c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */ b = II ( b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */ a = II ( a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */ d = II ( d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */ c = II ( c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */ b = II ( b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */ state[0] += a; state[1] += b; state[2] += c; state[3] += d; } }