1 /* ClientDiffieHellmanPublic.java -- Client Diffie-Hellman value. 2 Copyright (C) 2006 Free Software Foundation, Inc. 3 4 This file is a part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or (at 9 your option) any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19 USA 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.javax.net.ssl.provider; 40 41 import java.io.PrintWriter; 42 import java.io.StringWriter; 43 44 import java.math.BigInteger; 45 46 import java.nio.ByteBuffer; 47 48 /** 49 * The client's explicit Diffie Hellman value. 50 * 51 * <pre> 52 struct { 53 select (PublicValueEncoding) { 54 case implicit: struct { }; 55 case explicit: opaque dh_Yc<1..2^16-1>; 56 } dh_public; 57 } ClientDiffieHellmanPublic;</pre> 58 */ 59 public class ClientDiffieHellmanPublic extends ExchangeKeys implements Builder 60 { ClientDiffieHellmanPublic(final ByteBuffer buffer)61 public ClientDiffieHellmanPublic(final ByteBuffer buffer) 62 { 63 super(buffer); 64 } 65 ClientDiffieHellmanPublic(final BigInteger Yc)66 public ClientDiffieHellmanPublic(final BigInteger Yc) 67 { 68 super(wrap(Yc)); 69 } 70 wrap(BigInteger Yc)71 private static ByteBuffer wrap(BigInteger Yc) 72 { 73 byte[] b = Util.trim(Yc); 74 ByteBuffer ret = ByteBuffer.allocate(b.length + 2); 75 ret.putShort((short) b.length); 76 ret.put(b); 77 return (ByteBuffer) ret.rewind(); 78 } 79 buffer()80 public ByteBuffer buffer() 81 { 82 return (ByteBuffer) buffer.duplicate().rewind().limit(length()); 83 } 84 publicValue()85 public BigInteger publicValue() 86 { 87 int len = length() - 2; 88 byte[] b = new byte[len]; 89 buffer.position(2); 90 buffer.get(b); 91 buffer.rewind(); 92 return new BigInteger(1, b); 93 } 94 setPublicValue(final BigInteger Yc)95 public void setPublicValue(final BigInteger Yc) 96 { 97 byte[] buf = Util.trim(Yc); 98 if (buffer.capacity() < buf.length + 2) 99 buffer = ByteBuffer.allocate(buf.length + 2); 100 buffer.putShort((short) buf.length); 101 buffer.put(buf); 102 buffer.rewind(); 103 } 104 length()105 public int length () 106 { 107 return (buffer.getShort(0) & 0xFFFF) + 2; 108 } 109 toString()110 public String toString () 111 { 112 return toString (null); 113 } 114 toString(final String prefix)115 public String toString (final String prefix) 116 { 117 StringWriter str = new StringWriter (); 118 PrintWriter out = new PrintWriter (str); 119 if (prefix != null) out.print (prefix); 120 out.println ("struct {"); 121 if (prefix != null) out.print (prefix); 122 out.print (" dh_Yc = "); 123 out.print (publicValue ().toString (16)); 124 out.println (';'); 125 if (prefix != null) out.print (prefix); 126 out.print ("} ClientDiffieHellmanPublic;"); 127 return str.toString (); 128 } 129 } 130