Source for gnu.javax.net.ssl.provider.Signature

   1: /* Signature.java -- SSL Signature structure.
   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: 
  46: /**
  47:  * The signature structure.
  48:  *
  49:  * <pre>
  50: select (SignatureAlgorithm)
  51: {
  52: case anonymous:
  53:   struct { };
  54: case rsa:
  55:   digitally-signed struct
  56:   {
  57:     opaque md5_hash[16];
  58:     opaque sha_hash[20];
  59:   };
  60: case dsa:
  61:   digitally-signed struct
  62:   {
  63:     opaque sha_hash[20];
  64:   };
  65: } Signature;</pre>
  66:  */
  67: public class Signature implements Builder, Constructed
  68: {
  69: 
  70:   // Fields.
  71:   // -------------------------------------------------------------------------
  72: 
  73:   private final ByteBuffer buffer;
  74:   private final SignatureAlgorithm alg;
  75: 
  76:   // Constructor.
  77:   // -------------------------------------------------------------------------
  78: 
  79:   public Signature (final ByteBuffer buffer, final SignatureAlgorithm alg)
  80:   {
  81:     this.buffer = buffer;
  82:     this.alg = alg;
  83:   }
  84: 
  85:   public Signature (final byte[] sigValue, final SignatureAlgorithm alg)
  86:   {
  87:     buffer = ByteBuffer.allocate(sigValue.length + 2);
  88:     buffer.putShort((short) sigValue.length);
  89:     buffer.put(sigValue);
  90:     buffer.position(0);
  91:     this.alg = alg;
  92:   }
  93: 
  94:   // Instance methods.
  95:   // -------------------------------------------------------------------------
  96: 
  97:   public int length ()
  98:   {
  99:     if (alg.equals (SignatureAlgorithm.ANONYMOUS))
 100:       return 0;
 101:     return (buffer.getShort (0) & 0xFFFF) + 2;
 102:   }
 103: 
 104:   public ByteBuffer buffer()
 105:   {
 106:     return (ByteBuffer) buffer.duplicate().limit(length());
 107:   }
 108: 
 109:   public byte[] signature ()
 110:   {
 111:     if (alg.equals (SignatureAlgorithm.ANONYMOUS))
 112:       return new byte[0];
 113:     int length = buffer.getShort (0) & 0xFFFF;
 114:     byte[] buf = new byte[length];
 115:     ((ByteBuffer) buffer.duplicate().position(2)).get(buf);
 116:     return buf;
 117:   }
 118: 
 119:   public void setSignature (final byte[] signature)
 120:   {
 121:     setSignature (signature, 0, signature.length);
 122:   }
 123: 
 124:   public void setSignature (final byte[] signature, final int offset, final int length)
 125:   {
 126:     if (alg.equals (SignatureAlgorithm.ANONYMOUS))
 127:       return;
 128:     buffer.putShort (0, (short) length);
 129:     buffer.position (2);
 130:     buffer.put (signature, offset, length);
 131:   }
 132: 
 133:   public String toString ()
 134:   {
 135:     return toString (null);
 136:   }
 137: 
 138:   public String toString (final String prefix)
 139:   {
 140:     StringWriter str = new StringWriter();
 141:     PrintWriter out = new PrintWriter(str);
 142:     if (prefix != null)
 143:       out.print (prefix);
 144:     out.println("struct {");
 145:     if (!alg.equals (SignatureAlgorithm.ANONYMOUS))
 146:       {
 147:         String subprefix = "  ";
 148:         if (prefix != null)
 149:           subprefix = prefix + subprefix;
 150:         out.print (Util.hexDump (signature (), subprefix));
 151:       }
 152:     if (prefix != null)
 153:       out.print (prefix);
 154:     out.print ("} Signature;");
 155:     return str.toString();
 156:   }
 157: }