1 /*

     2  * Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package sun.security.ssl;

    27 

    28 import java.io.IOException;

    29 import java.util.ArrayList;

    30 import java.util.List;

    31 

    32 import javax.net.ssl.SSLProtocolException;

    33 

    34 final class EllipticPointFormatsExtension extends HelloExtension {

    35 

    36     static final int FMT_UNCOMPRESSED = 0;

    37     static final int FMT_ANSIX962_COMPRESSED_PRIME = 1;

    38     static final int FMT_ANSIX962_COMPRESSED_CHAR2 = 2;

    39 

    40     static final HelloExtension DEFAULT =

    41             new EllipticPointFormatsExtension(new byte[] {FMT_UNCOMPRESSED});

    42 

    43     private final byte[] formats;

    44 

    45     private EllipticPointFormatsExtension(byte[] formats) {

    46         super(ExtensionType.EXT_EC_POINT_FORMATS);

    47         this.formats = formats;

    48     }

    49 

    50     EllipticPointFormatsExtension(HandshakeInStream s, int len)

    51             throws IOException {

    52         super(ExtensionType.EXT_EC_POINT_FORMATS);

    53         formats = s.getBytes8();

    54         // RFC 4492 says uncompressed points must always be supported.

    55         // Check just to make sure.

    56         boolean uncompressed = false;

    57         for (int format : formats) {

    58             if (format == FMT_UNCOMPRESSED) {

    59                 uncompressed = true;

    60                 break;

    61             }

    62         }

    63         if (uncompressed == false) {

    64             throw new SSLProtocolException

    65                 ("Peer does not support uncompressed points");

    66         }

    67     }

    68 

    69     @Override

    70     int length() {

    71         return 5 + formats.length;

    72     }

    73 

    74     @Override

    75     void send(HandshakeOutStream s) throws IOException {

    76         s.putInt16(type.id);

    77         s.putInt16(formats.length + 1);

    78         s.putBytes8(formats);

    79     }

    80 

    81     private static String toString(byte format) {

    82         int f = format & 0xff;

    83         switch (f) {

    84         case FMT_UNCOMPRESSED:

    85             return "uncompressed";

    86         case FMT_ANSIX962_COMPRESSED_PRIME:

    87             return "ansiX962_compressed_prime";

    88         case FMT_ANSIX962_COMPRESSED_CHAR2:

    89             return "ansiX962_compressed_char2";

    90         default:

    91             return "unknown-" + f;

    92         }

    93     }

    94 

    95     @Override

    96     public String toString() {

    97         List<String> list = new ArrayList<String>();

    98         for (byte format : formats) {

    99             list.add(toString(format));

   100         }

   101         return "Extension " + type + ", formats: " + list;

   102     }

   103 }