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Diffstat (limited to 'libjava/classpath/gnu/java/security/hash/MD2.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/hash/MD2.java | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/hash/MD2.java b/libjava/classpath/gnu/java/security/hash/MD2.java new file mode 100644 index 00000000000..41e876983bd --- /dev/null +++ b/libjava/classpath/gnu/java/security/hash/MD2.java @@ -0,0 +1,301 @@ +/* MD2.java -- + Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc. + +This file is a part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at +your option) any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 +USA + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.hash; + +import gnu.java.security.Registry; +import gnu.java.security.util.Util; + +/** + * <p>An implementation of the MD2 message digest algorithm.</p> + * + * <p>MD2 is not widely used. Unless it is needed for compatibility with + * existing systems, it is not recommended for use in new applications.</p> + * + * <p>References:</p> + * + * <ol> + * <li>The <a href="http://www.ietf.org/rfc/rfc1319.txt">MD2</a> + * Message-Digest Algorithm.<br> + * B. Kaliski.</li> + * <li>The <a href="http://www.rfc-editor.org/errata.html">RFC ERRATA PAGE</a> + * under section RFC 1319.</li> + * </ol> + */ +public class MD2 extends BaseHash +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + /** An MD2 message digest is always 128-bits long, or 16 bytes. */ + private static final int DIGEST_LENGTH = 16; + + /** The MD2 algorithm operates on 128-bit blocks, or 16 bytes. */ + private static final int BLOCK_LENGTH = 16; + + /** 256 byte "random" permutation of the digits of pi. */ + private static final byte[] PI = { 41, 46, 67, -55, -94, -40, 124, 1, 61, 54, + 84, -95, -20, -16, 6, 19, 98, -89, 5, -13, + -64, -57, 115, -116, -104, -109, 43, -39, + -68, 76, -126, -54, 30, -101, 87, 60, -3, + -44, -32, 22, 103, 66, 111, 24, -118, 23, + -27, 18, -66, 78, -60, -42, -38, -98, -34, + 73, -96, -5, -11, -114, -69, 47, -18, 122, + -87, 104, 121, -111, 21, -78, 7, 63, -108, + -62, 16, -119, 11, 34, 95, 33, -128, 127, + 93, -102, 90, -112, 50, 39, 53, 62, -52, + -25, -65, -9, -105, 3, -1, 25, 48, -77, 72, + -91, -75, -47, -41, 94, -110, 42, -84, 86, + -86, -58, 79, -72, 56, -46, -106, -92, 125, + -74, 118, -4, 107, -30, -100, 116, 4, -15, + 69, -99, 112, 89, 100, 113, -121, 32, -122, + 91, -49, 101, -26, 45, -88, 2, 27, 96, 37, + -83, -82, -80, -71, -10, 28, 70, 97, 105, + 52, 64, 126, 15, 85, 71, -93, 35, -35, 81, + -81, 58, -61, 92, -7, -50, -70, -59, -22, + 38, 44, 83, 13, 110, -123, 40, -124, 9, + -45, -33, -51, -12, 65, -127, 77, 82, 106, + -36, 55, -56, 108, -63, -85, -6, 36, -31, + 123, 8, 12, -67, -79, 74, 120, -120, -107, + -117, -29, 99, -24, 109, -23, -53, -43, -2, + 59, 0, 29, 57, -14, -17, -73, 14, 102, 88, + -48, -28, -90, 119, 114, -8, -21, 117, 75, + 10, 49, 68, 80, -76, -113, -19, 31, 26, + -37, -103, -115, 51, -97, 17, -125, 20 }; + + /** The output of this message digest when no data has been input. */ + private static final String DIGEST0 = "8350E5A3E24C153DF2275C9F80692773"; + + /** caches the result of the correctness test, once executed. */ + private static Boolean valid; + + /** The checksum computed so far. */ + private byte[] checksum; + + /** + * Work array needed by encrypt method. First <code>BLOCK_LENGTH</code> bytes + * are also used to store the running digest. + */ + private byte[] work; + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** Creates a new MD2 digest ready for use. */ + public MD2() + { + super(Registry.MD2_HASH, DIGEST_LENGTH, BLOCK_LENGTH); + } + + /** + * <p>Private constructor used for cloning.</p> + * + * @param md2 the instance to clone. + */ + private MD2(MD2 md2) + { + this(); + + // superclass field + this.count = md2.count; + this.buffer = (byte[]) md2.buffer.clone(); + + // private field + this.checksum = (byte[]) md2.checksum.clone(); + this.work = (byte[]) md2.work.clone(); + } + + // Class methods + // ------------------------------------------------------------------------- + + // Instance methods + // ------------------------------------------------------------------------- + + // java.lang.Cloneable interface implementation ---------------------------- + + public Object clone() + { + return new MD2(this); + } + + // Implementation of abstract methods in BaseHash -------------------------- + + protected byte[] getResult() + { + byte[] result = new byte[DIGEST_LENGTH]; + + // Encrypt checksum as last block. + encryptBlock(checksum, 0); + + for (int i = 0; i < BLOCK_LENGTH; i++) + { + result[i] = work[i]; + } + + return result; + } + + protected void resetContext() + { + checksum = new byte[BLOCK_LENGTH]; + work = new byte[BLOCK_LENGTH * 3]; + } + + public boolean selfTest() + { + if (valid == null) + { + valid = new Boolean(DIGEST0.equals(Util.toString(new MD2().digest()))); + } + return valid.booleanValue(); + } + + /** + * <p>Generates an array of padding bytes. The padding is defined as + * <code>i</code> bytes of value <code>i</code>, where <code>i</code> is the + * number of bytes to fill the last block of the message to + * <code>BLOCK_LENGTH</code> bytes (or <code>BLOCK_LENGTH</code> bytes when + * the last block was completely full).</p> + * + * @return the bytes to pad the remaining bytes in the buffer before + * completing a hash operation. + */ + protected byte[] padBuffer() + { + int length = BLOCK_LENGTH - (int) (count % BLOCK_LENGTH); + if (length == 0) + { + length = BLOCK_LENGTH; + } + byte[] pad = new byte[length]; + for (int i = 0; i < length; i++) + { + pad[i] = (byte) length; + } + return pad; + } + + /** + * <p>Adds <code>BLOCK_LENGTH</code> bytes to the running digest.</p> + * + * @param in the byte array to take the <code>BLOCK_LENGTH</code> bytes from. + * @param off the offset to start from in the given byte array. + */ + protected void transform(byte[] in, int off) + { + // encryptBlock(in, off); + // updateCheckSum(in, off); + updateCheckSumAndEncryptBlock(in, off); + } + + // Private instance methods ------------------------------------------------ + + /** + * Updates the checksum with the <code>BLOCK_LENGTH</code> bytes from the + * given array starting at <code>off</code>. + */ + /* + private void updateCheckSum(byte[] in, int off) { + byte l = checksum[BLOCK_LENGTH-1]; + for (int i = 0; i < BLOCK_LENGTH; i++) { + byte b = in[off+i]; + // l = (byte)((checksum[i] & 0xFF) ^ (PI[((b & 0xFF) ^ (l & 0xFF))] & 0xFF)); + l = (byte)(checksum[i] ^ PI[(b ^ l) & 0xFF]); + checksum[i] = l; + } + } + */ + /** + * Adds a new block (<code>BLOCK_LENGTH</code> bytes) to the running digest + * from the given byte array starting from the given offset. + */ + private void encryptBlock(byte[] in, int off) + { + for (int i = 0; i < BLOCK_LENGTH; i++) + { + byte b = in[off + i]; + work[BLOCK_LENGTH + i] = b; + work[BLOCK_LENGTH * 2 + i] = (byte) (work[i] ^ b); + } + + byte t = 0; + for (int i = 0; i < 18; i++) + { + for (int j = 0; j < 3 * BLOCK_LENGTH; j++) + { + // t = (byte)((work[j] & 0xFF) ^ (PI[t & 0xFF] & 0xFF)); + t = (byte) (work[j] ^ PI[t & 0xFF]); + work[j] = t; + } + // t = (byte)((t + i) & 0xFF); + t = (byte) (t + i); + } + } + + /** + * Optimized method that combines a checksum update and encrypt of a block. + */ + private void updateCheckSumAndEncryptBlock(byte[] in, int off) + { + byte l = checksum[BLOCK_LENGTH - 1]; + for (int i = 0; i < BLOCK_LENGTH; i++) + { + byte b = in[off + i]; + work[BLOCK_LENGTH + i] = b; + // work[BLOCK_LENGTH*2+i] = (byte)((work[i] & 0xFF) ^ (b & 0xFF)); + work[BLOCK_LENGTH * 2 + i] = (byte) (work[i] ^ b); + // l = (byte)((checksum[i] & 0xFF) ^ (PI[((b & 0xFF) ^ (l & 0xFF))] & 0xFF)); + l = (byte) (checksum[i] ^ PI[(b ^ l) & 0xFF]); + checksum[i] = l; + } + + byte t = 0; + for (int i = 0; i < 18; i++) + { + for (int j = 0; j < 3 * BLOCK_LENGTH; j++) + { + // t = (byte)((work[j] & 0xFF) ^ (PI[t & 0xFF] & 0xFF)); + t = (byte) (work[j] ^ PI[t & 0xFF]); + work[j] = t; + } + // t = (byte)((t + i) & 0xFF); + t = (byte) (t + i); + } + } +} |
