Source for gnu.java.security.sig.rsa.RSAPSSSignatureRawCodec

   1: /* RSAPSSSignatureRawCodec.java --
   2:    Copyright (C) 2001, 2002, 2003, 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.java.security.sig.rsa;
  40: 
  41: import gnu.java.security.Registry;
  42: import gnu.java.security.sig.ISignatureCodec;
  43: 
  44: import java.io.ByteArrayOutputStream;
  45: 
  46: /**
  47:  * An object that implements the {@link ISignatureCodec} operations for the
  48:  * <i>Raw</i> format to use with RSA-PSS signatures.
  49:  */
  50: public class RSAPSSSignatureRawCodec
  51:     implements ISignatureCodec
  52: {
  53:   // implicit 0-arguments constructor
  54: 
  55:   public int getFormatID()
  56:   {
  57:     return RAW_FORMAT;
  58:   }
  59: 
  60:   /**
  61:    * Returns the encoded form of the designated RSA-PSS signature object
  62:    * according to the <i>Raw</i> format supported by this library.
  63:    * <p>
  64:    * The <i>Raw</i> format for an RSA-PSS signature, in this implementation, is
  65:    * a byte sequence consisting of the following:
  66:    * <ol>
  67:    * <li>4-byte magic consisting of the value of the literal
  68:    * {@link Registry#MAGIC_RAW_RSA_PSS_SIGNATURE},
  69:    * <li>
  70:    * <li>1-byte version consisting of the constant: 0x01,</li>
  71:    * <li>4-byte count of following bytes representing the RSA-PSS signature
  72:    * bytes in internet order,</li>
  73:    * <li>the RSA-PSS signature bytes in internet order.</li>
  74:    * </ol>
  75:    *
  76:    * @param signature the signature to encode, consisting of the output of the
  77:    *          <code>sign()</code> method of a {@link RSAPSSSignature} instance
  78:    *          --a byte array.
  79:    * @return the <i>Raw</i> format encoding of the designated signature.
  80:    * @exception IllegalArgumentException if the designated signature is not an
  81:    *              RSA-PSS one.
  82:    */
  83:   public byte[] encodeSignature(Object signature)
  84:   {
  85:     byte[] buffer;
  86:     try
  87:       {
  88:         buffer = (byte[]) signature;
  89:       }
  90:     catch (Exception x)
  91:       {
  92:         throw new IllegalArgumentException("signature");
  93:       }
  94:     ByteArrayOutputStream baos = new ByteArrayOutputStream();
  95:     // magic
  96:     baos.write(Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[0]);
  97:     baos.write(Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[1]);
  98:     baos.write(Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[2]);
  99:     baos.write(Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[3]);
 100:     // version
 101:     baos.write(0x01);
 102:     // signature bytes
 103:     int length = buffer.length;
 104:     baos.write( length >>> 24);
 105:     baos.write((length >>> 16) & 0xFF);
 106:     baos.write((length >>> 8) & 0xFF);
 107:     baos.write(length & 0xFF);
 108:     baos.write(buffer, 0, length);
 109:     return baos.toByteArray();
 110:   }
 111: 
 112:   public Object decodeSignature(byte[] k)
 113:   {
 114:     // magic
 115:     if (k[0] != Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[0]
 116:         || k[1] != Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[1]
 117:         || k[2] != Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[2]
 118:         || k[3] != Registry.MAGIC_RAW_RSA_PSS_SIGNATURE[3])
 119:       throw new IllegalArgumentException("magic");
 120:     // version
 121:     if (k[4] != 0x01)
 122:       throw new IllegalArgumentException("version");
 123:     int i = 5;
 124:     int l;
 125:     // signature bytes
 126:     l =  k[i++]         << 24
 127:       | (k[i++] & 0xFF) << 16
 128:       | (k[i++] & 0xFF) << 8
 129:       | (k[i++] & 0xFF);
 130:     byte[] result = new byte[l];
 131:     System.arraycopy(k, i, result, 0, l);
 132:     return result;
 133:   }
 134: }