1 /* ServerKeyExchange.java -- SSL ServerKeyExchange message.
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.nio.ByteBuffer;
45 import java.nio.ByteOrder;
46 
47 /**
48  * The server key exchange message.
49  *
50  * <pre>
51 struct
52 {
53   select (KeyExchangeAlgorithm)
54   {
55     case diffie_hellman:
56       ServerDHParams params;
57       Signature signed_params;
58     case rsa:
59       ServerRSAParams params;
60       Signature signed_params;
61     case srp:
62       ServerSRPParams params;
63       Signature signed_params;
64   };
65 } ServerKeyExchange;
66 </pre>
67  */
68 public class ServerKeyExchange implements Handshake.Body
69 {
70 
71   protected ByteBuffer buffer;
72   protected final CipherSuite suite;
73 
ServerKeyExchange(final ByteBuffer buffer, final CipherSuite suite)74   public ServerKeyExchange(final ByteBuffer buffer, final CipherSuite suite)
75   {
76     suite.getClass();
77     this.buffer = buffer.duplicate().order(ByteOrder.BIG_ENDIAN);
78     this.suite = suite;
79   }
80 
length()81   public int length ()
82   {
83     if (suite.keyExchangeAlgorithm ().equals (KeyExchangeAlgorithm.NONE))
84       return 0;
85     int len = 0;
86     ServerKeyExchangeParams params = params();
87     Signature sig = signature();
88     if (params != null)
89       len += params.length();
90     if (sig != null)
91       len += sig.length();
92     return len;
93   }
94 
95   /**
96    * Returns the server's key exchange parameters. The value returned will
97    * depend on the key exchange algorithm this object was created with.
98    *
99    * @return The server's key exchange parameters.
100    */
params()101   public ServerKeyExchangeParams params ()
102   {
103     KeyExchangeAlgorithm kex = suite.keyExchangeAlgorithm ();
104     if (kex == KeyExchangeAlgorithm.RSA)
105       return new ServerRSAParams(buffer.duplicate ());
106     else if (kex == KeyExchangeAlgorithm.DHE_DSS
107              || kex == KeyExchangeAlgorithm.DHE_RSA
108              || kex == KeyExchangeAlgorithm.DH_anon)
109       return new ServerDHParams(buffer.duplicate());
110 //     else if (kex.equals (KeyExchangeAlgorithm.SRP))
111 //       return new ServerSRPParams (buffer.duplicate ());
112     else if (kex == KeyExchangeAlgorithm.NONE)
113       return null;
114     else if (kex == KeyExchangeAlgorithm.DHE_PSK)
115       return new ServerDHE_PSKParameters(buffer.duplicate());
116     else if (kex == KeyExchangeAlgorithm.PSK)
117       return new ServerPSKParameters(buffer.duplicate());
118     else if (kex == KeyExchangeAlgorithm.RSA_PSK)
119       return new ServerPSKParameters(buffer.duplicate());
120     throw new IllegalArgumentException ("unsupported key exchange: " + kex);
121   }
122 
123   /**
124    * Returns the digital signature made over the key exchange parameters.
125    *
126    * @return The signature.
127    */
signature()128   public Signature signature ()
129   {
130     KeyExchangeAlgorithm kex = suite.keyExchangeAlgorithm();
131     if (kex == KeyExchangeAlgorithm.NONE
132         || kex == KeyExchangeAlgorithm.DH_anon
133         || kex == KeyExchangeAlgorithm.DHE_PSK
134         || kex == KeyExchangeAlgorithm.PSK
135         || kex == KeyExchangeAlgorithm.RSA_PSK)
136       return null;
137     ServerKeyExchangeParams params = params();
138     ByteBuffer sigbuf = ((ByteBuffer) buffer.position(params.length ())).slice ();
139     return new Signature (sigbuf, suite.signatureAlgorithm ());
140   }
141 
toString()142   public String toString()
143   {
144     return toString (null);
145   }
146 
toString(final String prefix)147   public String toString (final String prefix)
148   {
149     StringWriter str = new StringWriter();
150     PrintWriter out = new PrintWriter(str);
151     if (prefix != null) out.print (prefix);
152     out.println("struct {");
153     if (prefix != null) out.print (prefix);
154     out.print ("  algorithm: ");
155     out.print (suite.keyExchangeAlgorithm ());
156     out.println (";");
157     if (!suite.keyExchangeAlgorithm ().equals (KeyExchangeAlgorithm.NONE))
158       {
159         if (prefix != null) out.print (prefix);
160         out.println ("  parameters:");
161         out.println (params ().toString (prefix != null ? prefix+"  " : "  "));
162       }
163     if (!suite.signatureAlgorithm ().equals (SignatureAlgorithm.ANONYMOUS))
164       {
165         if (prefix != null) out.print (prefix);
166         out.println ("  signature:");
167         out.println (signature ().toString (prefix != null ? prefix+"  " : "  "));
168       }
169     if (prefix != null) out.print (prefix);
170     out.print ("} ServerKeyExchange;");
171     return str.toString();
172   }
173 }
174