gcc/libjava/classpath/gnu/java/security/hash/MD5.java

/* MD5.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
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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.

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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
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permission to link this library with independent modules to produce an
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independent module, the terms and conditions of the license of that
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exception statement from your version.  */


package gnu.java.security.hash;

import gnu.java.security.Registry;
import gnu.java.security.util.Util;

/**
 * <p>The MD5 message-digest algorithm takes as input a message of arbitrary
 * length and produces as output a 128-bit "fingerprint" or "message digest" of
 * the input. It is conjectured that it is computationally infeasible to
 * produce two messages having the same message digest, or to produce any
 * message having a given prespecified target message digest.</p>
 *
 * <p>References:</p>
 *
 * <ol>
 *    <li>The <a href="http://www.ietf.org/rfc/rfc1321.txt">MD5</a> Message-
 *    Digest Algorithm.<br>
 *    R. Rivest.</li>
 * </ol>
 */
public class MD5 extends BaseHash
{

  // Constants and variables
  // -------------------------------------------------------------------------

  private static final int BLOCK_SIZE = 64; // inner block size in bytes

  private static final String DIGEST0 = "D41D8CD98F00B204E9800998ECF8427E";

  /** caches the result of the correctness test, once executed. */
  private static Boolean valid;

  /** 128-bit interim result. */
  private int h0, h1, h2, h3;

  // Constructor(s)
  // -------------------------------------------------------------------------

  /** Trivial 0-arguments constructor. */
  public MD5()
  {
    super(Registry.MD5_HASH, 16, BLOCK_SIZE);
  }

  /**
   * <p>Private constructor for cloning purposes.</p>
   *
   * @param md the instance to clone.
   */
  private MD5(MD5 md)
  {
    this();

    this.h0 = md.h0;
    this.h1 = md.h1;
    this.h2 = md.h2;
    this.h3 = md.h3;
    this.count = md.count;
    this.buffer = (byte[]) md.buffer.clone();
  }

  // Class methods
  // -------------------------------------------------------------------------

  // Instance methods
  // -------------------------------------------------------------------------

  // java.lang.Cloneable interface implementation ----------------------------

  public Object clone()
  {
    return new MD5(this);
  }

  // Implementation of concrete methods in BaseHash --------------------------

  protected synchronized void transform(byte[] in, int i)
  {
    int X0 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X1 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X2 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X3 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X4 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X5 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X6 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X7 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X8 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X9 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
             | in[i++] << 24;
    int X10 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i++] << 24;
    int X11 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i++] << 24;
    int X12 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i++] << 24;
    int X13 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i++] << 24;
    int X14 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i++] << 24;
    int X15 = (in[i++] & 0xFF) | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF) << 16
              | in[i] << 24;

    int A = h0;
    int B = h1;
    int C = h2;
    int D = h3;

    // hex constants are from md5.c in FSF Gnu Privacy Guard 0.9.2
    // round 1
    A += ((B & C) | (~B & D)) + X0 + 0xD76AA478;
    A = B + (A << 7 | A >>> -7);
    D += ((A & B) | (~A & C)) + X1 + 0xE8C7B756;
    D = A + (D << 12 | D >>> -12);
    C += ((D & A) | (~D & B)) + X2 + 0x242070DB;
    C = D + (C << 17 | C >>> -17);
    B += ((C & D) | (~C & A)) + X3 + 0xC1BDCEEE;
    B = C + (B << 22 | B >>> -22);

    A += ((B & C) | (~B & D)) + X4 + 0xF57C0FAF;
    A = B + (A << 7 | A >>> -7);
    D += ((A & B) | (~A & C)) + X5 + 0x4787C62A;
    D = A + (D << 12 | D >>> -12);
    C += ((D & A) | (~D & B)) + X6 + 0xA8304613;
    C = D + (C << 17 | C >>> -17);
    B += ((C & D) | (~C & A)) + X7 + 0xFD469501;
    B = C + (B << 22 | B >>> -22);

    A += ((B & C) | (~B & D)) + X8 + 0x698098D8;
    A = B + (A << 7 | A >>> -7);
    D += ((A & B) | (~A & C)) + X9 + 0x8B44F7AF;
    D = A + (D << 12 | D >>> -12);
    C += ((D & A) | (~D & B)) + X10 + 0xFFFF5BB1;
    C = D + (C << 17 | C >>> -17);
    B += ((C & D) | (~C & A)) + X11 + 0x895CD7BE;
    B = C + (B << 22 | B >>> -22);

    A += ((B & C) | (~B & D)) + X12 + 0x6B901122;
    A = B + (A << 7 | A >>> -7);
    D += ((A & B) | (~A & C)) + X13 + 0xFD987193;
    D = A + (D << 12 | D >>> -12);
    C += ((D & A) | (~D & B)) + X14 + 0xA679438E;
    C = D + (C << 17 | C >>> -17);
    B += ((C & D) | (~C & A)) + X15 + 0x49B40821;
    B = C + (B << 22 | B >>> -22);

    // round 2
    A += ((B & D) | (C & ~D)) + X1 + 0xF61E2562;
    A = B + (A << 5 | A >>> -5);
    D += ((A & C) | (B & ~C)) + X6 + 0xC040B340;
    D = A + (D << 9 | D >>> -9);
    C += ((D & B) | (A & ~B)) + X11 + 0x265E5A51;
    C = D + (C << 14 | C >>> -14);
    B += ((C & A) | (D & ~A)) + X0 + 0xE9B6C7AA;
    B = C + (B << 20 | B >>> -20);

    A += ((B & D) | (C & ~D)) + X5 + 0xD62F105D;
    A = B + (A << 5 | A >>> -5);
    D += ((A & C) | (B & ~C)) + X10 + 0x02441453;
    D = A + (D << 9 | D >>> -9);
    C += ((D & B) | (A & ~B)) + X15 + 0xD8A1E681;
    C = D + (C << 14 | C >>> -14);
    B += ((C & A) | (D & ~A)) + X4 + 0xE7D3FBC8;
    B = C + (B << 20 | B >>> -20);

    A += ((B & D) | (C & ~D)) + X9 + 0x21E1CDE6;
    A = B + (A << 5 | A >>> -5);
    D += ((A & C) | (B & ~C)) + X14 + 0xC33707D6;
    D = A + (D << 9 | D >>> -9);
    C += ((D & B) | (A & ~B)) + X3 + 0xF4D50D87;
    C = D + (C << 14 | C >>> -14);
    B += ((C & A) | (D & ~A)) + X8 + 0x455A14ED;
    B = C + (B << 20 | B >>> -20);

    A += ((B & D) | (C & ~D)) + X13 + 0xA9E3E905;
    A = B + (A << 5 | A >>> -5);
    D += ((A & C) | (B & ~C)) + X2 + 0xFCEFA3F8;
    D = A + (D << 9 | D >>> -9);
    C += ((D & B) | (A & ~B)) + X7 + 0x676F02D9;
    C = D + (C << 14 | C >>> -14);
    B += ((C & A) | (D & ~A)) + X12 + 0x8D2A4C8A;
    B = C + (B << 20 | B >>> -20);

    // round 3
    A += (B ^ C ^ D) + X5 + 0xFFFA3942;
    A = B + (A << 4 | A >>> -4);
    D += (A ^ B ^ C) + X8 + 0x8771F681;
    D = A + (D << 11 | D >>> -11);
    C += (D ^ A ^ B) + X11 + 0x6D9D6122;
    C = D + (C << 16 | C >>> -16);
    B += (C ^ D ^ A) + X14 + 0xFDE5380C;
    B = C + (B << 23 | B >>> -23);

    A += (B ^ C ^ D) + X1 + 0xA4BEEA44;
    A = B + (A << 4 | A >>> -4);
    D += (A ^ B ^ C) + X4 + 0x4BDECFA9;
    D = A + (D << 11 | D >>> -11);
    C += (D ^ A ^ B) + X7 + 0xF6BB4B60;
    C = D + (C << 16 | C >>> -16);
    B += (C ^ D ^ A) + X10 + 0xBEBFBC70;
    B = C + (B << 23 | B >>> -23);

    A += (B ^ C ^ D) + X13 + 0x289B7EC6;
    A = B + (A << 4 | A >>> -4);
    D += (A ^ B ^ C) + X0 + 0xEAA127FA;
    D = A + (D << 11 | D >>> -11);
    C += (D ^ A ^ B) + X3 + 0xD4EF3085;
    C = D + (C << 16 | C >>> -16);
    B += (C ^ D ^ A) + X6 + 0x04881D05;
    B = C + (B << 23 | B >>> -23);

    A += (B ^ C ^ D) + X9 + 0xD9D4D039;
    A = B + (A << 4 | A >>> -4);
    D += (A ^ B ^ C) + X12 + 0xE6DB99E5;
    D = A + (D << 11 | D >>> -11);
    C += (D ^ A ^ B) + X15 + 0x1FA27CF8;
    C = D + (C << 16 | C >>> -16);
    B += (C ^ D ^ A) + X2 + 0xC4AC5665;
    B = C + (B << 23 | B >>> -23);

    // round 4
    A += (C ^ (B | ~D)) + X0 + 0xF4292244;
    A = B + (A << 6 | A >>> -6);
    D += (B ^ (A | ~C)) + X7 + 0x432AFF97;
    D = A + (D << 10 | D >>> -10);
    C += (A ^ (D | ~B)) + X14 + 0xAB9423A7;
    C = D + (C << 15 | C >>> -15);
    B += (D ^ (C | ~A)) + X5 + 0xFC93A039;
    B = C + (B << 21 | B >>> -21);

    A += (C ^ (B | ~D)) + X12 + 0x655B59C3;
    A = B + (A << 6 | A >>> -6);
    D += (B ^ (A | ~C)) + X3 + 0x8F0CCC92;
    D = A + (D << 10 | D >>> -10);
    C += (A ^ (D | ~B)) + X10 + 0xFFEFF47D;
    C = D + (C << 15 | C >>> -15);
    B += (D ^ (C | ~A)) + X1 + 0x85845dd1;
    B = C + (B << 21 | B >>> -21);

    A += (C ^ (B | ~D)) + X8 + 0x6FA87E4F;
    A = B + (A << 6 | A >>> -6);
    D += (B ^ (A | ~C)) + X15 + 0xFE2CE6E0;
    D = A + (D << 10 | D >>> -10);
    C += (A ^ (D | ~B)) + X6 + 0xA3014314;
    C = D + (C << 15 | C >>> -15);
    B += (D ^ (C | ~A)) + X13 + 0x4E0811A1;
    B = C + (B << 21 | B >>> -21);

    A += (C ^ (B | ~D)) + X4 + 0xF7537E82;
    A = B + (A << 6 | A >>> -6);
    D += (B ^ (A | ~C)) + X11 + 0xBD3AF235;
    D = A + (D << 10 | D >>> -10);
    C += (A ^ (D | ~B)) + X2 + 0x2AD7D2BB;
    C = D + (C << 15 | C >>> -15);
    B += (D ^ (C | ~A)) + X9 + 0xEB86D391;
    B = C + (B << 21 | B >>> -21);

    h0 += A;
    h1 += B;
    h2 += C;
    h3 += D;
  }

  protected byte[] padBuffer()
  {
    int n = (int) (count % BLOCK_SIZE);
    int padding = (n < 56) ? (56 - n) : (120 - n);
    byte[] result = new byte[padding + 8];

    // padding is always binary 1 followed by binary 0s
    result[0] = (byte) 0x80;

    // save number of bits, casting the long to an array of 8 bytes
    long bits = count << 3;
    result[padding++] = (byte) bits;
    result[padding++] = (byte) (bits >>> 8);
    result[padding++] = (byte) (bits >>> 16);
    result[padding++] = (byte) (bits >>> 24);
    result[padding++] = (byte) (bits >>> 32);
    result[padding++] = (byte) (bits >>> 40);
    result[padding++] = (byte) (bits >>> 48);
    result[padding] = (byte) (bits >>> 56);

    return result;
  }

  protected byte[] getResult()
  {
    byte[] result = new byte[] { (byte) h0, (byte) (h0 >>> 8),
                                (byte) (h0 >>> 16), (byte) (h0 >>> 24),
                                (byte) h1, (byte) (h1 >>> 8),
                                (byte) (h1 >>> 16), (byte) (h1 >>> 24),
                                (byte) h2, (byte) (h2 >>> 8),
                                (byte) (h2 >>> 16), (byte) (h2 >>> 24),
                                (byte) h3, (byte) (h3 >>> 8),
                                (byte) (h3 >>> 16), (byte) (h3 >>> 24) };

    return result;
  }

  protected void resetContext()
  {
    // magic MD5/RIPEMD128 initialisation constants
    h0 = 0x67452301;
    h1 = 0xEFCDAB89;
    h2 = 0x98BADCFE;
    h3 = 0x10325476;
  }

  public boolean selfTest()
  {
    if (valid == null)
      {
        valid = Boolean.valueOf(DIGEST0.equals(Util.toString(new MD5().digest())));
      }
    return valid.booleanValue();
  }
}