sslciphersuitewithmd5mac.java

这是linux下ssl vpn的实现程序

/*
 *  SSL-Explorer
 *
 *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
 *
 *  This program 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.
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
			
package com.maverick.ssl;

import com.maverick.crypto.digests.MD5Digest;

/**
 * An abstract {@link SSLCipherSuite} that uses an MD5 message digest.
 *
 * @author Lee David Painter
 * @version $Revision: 1.1 $
 */
public abstract class SSLCipherSuiteWithMD5MAC
    implements SSLCipherSuite {

  MD5Digest generateDigest = new MD5Digest();
  MD5Digest verifyDigest = new MD5Digest();

  byte[] encryptMAC;
  byte[] decryptMAC;

  byte[] padding1 = new byte[] {
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36, 0x36, 0x36,
      0x36, 0x36, 0x36};

  byte[] padding2 = new byte[] {
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
      0x5c, 0x5c, 0x5c};

  public SSLCipherSuiteWithMD5MAC() {

  }

  public abstract int getKeyLength();

  public abstract int getIVLength();

  public abstract void encrypt(byte[] b, int offset, int len);

  public abstract void decrypt(byte[] b, int offset, int len);

  public final void init(byte[] encryptKey,
                         byte[] encryptIV,
                         byte[] encryptMAC,
                         byte[] decryptKey,
                         byte[] decryptIV,
                         byte[] decryptMAC) {
    this.encryptMAC = encryptMAC;
    this.decryptMAC = decryptMAC;

    init(encryptKey, encryptIV,
         decryptKey, decryptIV);
  }

  protected abstract void init(byte[] encryptKey,
                               byte[] encryptIV,
                               byte[] decryptKey,
                               byte[] decryptIV);

  public final int getMACLength() {
    return generateDigest.getDigestSize();
  }

  public byte[] generateMAC(byte[] b, int offset, int len, int type,
                            long sequenceNo) {
    return calculateMAC(generateDigest, b, offset, len, type, sequenceNo,
                        encryptMAC);
  }

  public boolean verifyMAC(byte[] b, int offset, int len, int type,
                           long sequenceNo,
                           byte[] mac, int macoff, int maclen) {
    byte[] gen = calculateMAC(verifyDigest, b, offset, len, type, sequenceNo,
                              decryptMAC);
    for (int i = 0; i < gen.length; i++) {
      if (gen[i] != mac[i + macoff]) {
        return false;
      }
    }
    return true;
  }

  private byte[] calculateMAC(MD5Digest digest, byte[] b, int off, int len,
                              int type, long sequenceNo, byte[] key) {
    digest.reset();

    digest.update(key, 0, key.length);
    digest.update(padding1, 0, padding1.length);
    digest.update( (byte) ( (sequenceNo >> 56) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 48) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 40) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 32) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 24) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 16) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 8) & 0xFF));
    digest.update( (byte) ( (sequenceNo >> 0) & 0xFF));

    digest.update( (byte) type);
    digest.update( (byte) ( (len >> 8) & 0xFF));
    digest.update( (byte) (len & 0xFF));

    digest.update(b, off, len);

    byte[] temp = new byte[digest.getDigestSize()];
    digest.doFinal(temp, 0);

    digest.reset();

    digest.update(key, 0, key.length);
    digest.update(padding2, 0, padding2.length);
    digest.update(temp, 0, temp.length);

    digest.doFinal(temp, 0);

    return temp;

  }

}