1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.harmony.xnet.provider.jsse; 19 20 import java.io.IOException; 21 import java.math.BigInteger; 22 import java.security.KeyFactory; 23 import java.security.interfaces.RSAPublicKey; 24 import java.security.spec.RSAPublicKeySpec; 25 26 /** 27 * 28 * Represents server key exchange message. 29 * @see <a href="http://www.ietf.org/rfc/rfc2246.txt">TLS 1.0 spec., 7.4.3. 30 * Server key exchange message.</a> 31 * 32 */ 33 public class ServerKeyExchange extends Message { 34 35 // ServerRSAParams ServerDHParams 36 final BigInteger par1; // rsa_modulus dh_p 37 final byte[] bytes1; 38 39 final BigInteger par2; // rsa_exponent dh_g 40 final byte[] bytes2; 41 42 final BigInteger par3; // dh_Ys 43 final byte[] bytes3; 44 45 /** 46 * Signature 47 */ 48 final byte[] hash; 49 50 private RSAPublicKey key; 51 52 /** 53 * Creates outbound message 54 * @param par1 rsa_modulus or dh_p 55 * @param par2 rsa_exponent or dh_g 56 * @param par3 dh_Ys for ServerDHParams; should be null for ServerRSAParams 57 * @param hash should be null for anonymous SignatureAlgorithm 58 */ 59 public ServerKeyExchange(BigInteger par1, BigInteger par2, BigInteger par3, 60 byte[] hash) { 61 this.par1 = par1; 62 this.par2 = par2; 63 this.par3 = par3; 64 this.hash = hash; 65 66 bytes1 = toUnsignedByteArray(this.par1); 67 68 bytes2 = toUnsignedByteArray(this.par2); 69 70 length = 4 + bytes1.length + bytes2.length; 71 if (hash != null) { 72 length += 2 + hash.length; 73 } 74 if (par3 == null) { 75 bytes3 = null; 76 return; 77 } 78 bytes3 = toUnsignedByteArray(this.par3); 79 length += 2 + bytes3.length; 80 } 81 82 /** 83 * Remove first byte if 0. Needed because BigInteger.toByteArray() sometimes 84 * returns a zero prefix. 85 */ 86 public static byte[] toUnsignedByteArray(BigInteger bi) { 87 if (bi == null) { 88 return null; 89 } 90 byte[] bb = bi.toByteArray(); 91 // bb is not null, and has at least 1 byte - ZERO is represented as [0] 92 if (bb[0] == 0) { 93 byte[] noZero = new byte[bb.length - 1]; 94 System.arraycopy(bb, 1, noZero, 0, noZero.length); 95 return noZero; 96 } else { 97 return bb; 98 } 99 } 100 101 /** 102 * Creates inbound message 103 * @param in 104 * @param length 105 * @param keyExchange 106 * @throws IOException 107 */ 108 public ServerKeyExchange(HandshakeIODataStream in, int length, 109 int keyExchange) throws IOException { 110 111 int size = in.readUint16(); 112 bytes1 = in.read(size); 113 par1 = new BigInteger(1, bytes1); 114 this.length = 2 + bytes1.length; 115 size = in.readUint16(); 116 bytes2 = in.read(size); 117 par2 = new BigInteger(1, bytes2); 118 this.length += 2 + bytes2.length; 119 if (keyExchange != CipherSuite.KEY_EXCHANGE_RSA_EXPORT) { 120 size = in.readUint16(); 121 bytes3 = in.read(size); 122 par3 = new BigInteger(1, bytes3); 123 this.length += 2 + bytes3.length; 124 } else { 125 par3 = null; 126 bytes3 = null; 127 } 128 if (keyExchange != CipherSuite.KEY_EXCHANGE_DH_anon_EXPORT 129 && keyExchange != CipherSuite.KEY_EXCHANGE_DH_anon) { 130 size = in.readUint16(); 131 hash = in.read(size); 132 this.length += 2 + hash.length; 133 } else { 134 hash = null; 135 } 136 if (this.length != length) { 137 fatalAlert(AlertProtocol.DECODE_ERROR, 138 "DECODE ERROR: incorrect ServerKeyExchange"); 139 } 140 } 141 142 /** 143 * Sends message 144 * @param out 145 */ 146 @Override 147 public void send(HandshakeIODataStream out) { 148 out.writeUint16(bytes1.length); 149 out.write(bytes1); 150 out.writeUint16(bytes2.length); 151 out.write(bytes2); 152 if (bytes3 != null) { 153 out.writeUint16(bytes3.length); 154 out.write(bytes3); 155 } 156 if (hash != null) { 157 out.writeUint16(hash.length); 158 out.write(hash); 159 } 160 } 161 162 /** 163 * Returns RSAPublicKey generated using ServerRSAParams 164 * (rsa_modulus and rsa_exponent). 165 * 166 * @return 167 */ 168 public RSAPublicKey getRSAPublicKey() { 169 if (key != null) { 170 return key; 171 } 172 try { 173 KeyFactory kf = KeyFactory.getInstance("RSA"); 174 key = (RSAPublicKey) kf.generatePublic(new RSAPublicKeySpec(par1, 175 par2)); 176 } catch (Exception e) { 177 return null; 178 } 179 return key; 180 } 181 182 /** 183 * Returns message type 184 * @return 185 */ 186 @Override 187 public int getType() { 188 return Handshake.SERVER_KEY_EXCHANGE; 189 } 190 191 } 192
