J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | package sun.security.ssl; |
| 28 | |
| 29 | import java.io.*; |
| 30 | import java.security.*; |
| 31 | import java.security.interfaces.*; |
| 32 | |
| 33 | import javax.crypto.*; |
| 34 | import javax.crypto.spec.*; |
| 35 | |
| 36 | import javax.net.ssl.*; |
| 37 | |
| 38 | import sun.security.internal.spec.TlsRsaPremasterSecretParameterSpec; |
| 39 | |
| 40 | /** |
| 41 | * This is the client key exchange message (CLIENT --> SERVER) used with |
| 42 | * all RSA key exchanges; it holds the RSA-encrypted pre-master secret. |
| 43 | * |
| 44 | * The message is encrypted using PKCS #1 block type 02 encryption with the |
| 45 | * server's public key. The padding and resulting message size is a function |
| 46 | * of this server's public key modulus size, but the pre-master secret is |
| 47 | * always exactly 48 bytes. |
| 48 | * |
| 49 | */ |
| 50 | final class RSAClientKeyExchange extends HandshakeMessage { |
| 51 | |
| 52 | /** |
| 53 | * The TLS spec says that the version in the RSA premaster secret must |
| 54 | * be the maximum version supported by the client (i.e. the version it |
| 55 | * requested in its client hello version). However, we (and other |
| 56 | * implementations) used to send the active negotiated version. The |
| 57 | * system property below allows to toggle the behavior. |
| 58 | * |
| 59 | * Default is "false" (old behavior) for compatibility reasons. This |
| 60 | * will be changed in the future. |
| 61 | */ |
| 62 | private final static String PROP_NAME = |
| 63 | "com.sun.net.ssl.rsaPreMasterSecretFix"; |
| 64 | |
| 65 | private final static boolean rsaPreMasterSecretFix = |
| 66 | Debug.getBooleanProperty(PROP_NAME, false); |
| 67 | |
| 68 | int messageType() { |
| 69 | return ht_client_key_exchange; |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * The following field values were encrypted with the server's public |
| 74 | * key (or temp key from server key exchange msg) and are presented |
| 75 | * here in DECRYPTED form. |
| 76 | */ |
| 77 | private ProtocolVersion protocolVersion; // preMaster [0,1] |
| 78 | SecretKey preMaster; |
| 79 | private byte[] encrypted; // same size as public modulus |
| 80 | |
| 81 | |
| 82 | /* |
| 83 | * Client randomly creates a pre-master secret and encrypts it |
| 84 | * using the server's RSA public key; only the server can decrypt |
| 85 | * it, using its RSA private key. Result is the same size as the |
| 86 | * server's public key, and uses PKCS #1 block format 02. |
| 87 | */ |
| 88 | RSAClientKeyExchange(ProtocolVersion protocolVersion, ProtocolVersion maxVersion, |
| 89 | SecureRandom generator, PublicKey publicKey) throws IOException { |
| 90 | if (publicKey.getAlgorithm().equals("RSA") == false) { |
| 91 | throw new SSLKeyException("Public key not of type RSA"); |
| 92 | } |
| 93 | this.protocolVersion = protocolVersion; |
| 94 | |
| 95 | int major, minor; |
| 96 | |
| 97 | if (rsaPreMasterSecretFix) { |
| 98 | major = maxVersion.major; |
| 99 | minor = maxVersion.minor; |
| 100 | } else { |
| 101 | major = protocolVersion.major; |
| 102 | minor = protocolVersion.minor; |
| 103 | } |
| 104 | |
| 105 | try { |
| 106 | KeyGenerator kg = JsseJce.getKeyGenerator("SunTlsRsaPremasterSecret"); |
| 107 | kg.init(new TlsRsaPremasterSecretParameterSpec(major, minor)); |
| 108 | preMaster = kg.generateKey(); |
| 109 | |
| 110 | Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1); |
| 111 | cipher.init(Cipher.WRAP_MODE, publicKey, generator); |
| 112 | encrypted = cipher.wrap(preMaster); |
| 113 | } catch (GeneralSecurityException e) { |
| 114 | throw (SSLKeyException)new SSLKeyException |
| 115 | ("RSA premaster secret error").initCause(e); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * Server gets the PKCS #1 (block format 02) data, decrypts |
| 121 | * it with its private key. |
| 122 | */ |
| 123 | RSAClientKeyExchange(ProtocolVersion currentVersion, HandshakeInStream input, |
| 124 | int messageSize, PrivateKey privateKey) throws IOException { |
| 125 | |
| 126 | if (privateKey.getAlgorithm().equals("RSA") == false) { |
| 127 | throw new SSLKeyException("Private key not of type RSA"); |
| 128 | } |
| 129 | |
| 130 | this.protocolVersion = currentVersion; |
| 131 | if (currentVersion.v >= ProtocolVersion.TLS10.v) { |
| 132 | encrypted = input.getBytes16(); |
| 133 | } else { |
| 134 | encrypted = new byte [messageSize]; |
| 135 | if (input.read(encrypted) != messageSize) { |
| 136 | throw new SSLProtocolException |
| 137 | ("SSL: read PreMasterSecret: short read"); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | try { |
| 142 | Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1); |
| 143 | cipher.init(Cipher.UNWRAP_MODE, privateKey); |
| 144 | preMaster = (SecretKey)cipher.unwrap(encrypted, |
| 145 | "TlsRsaPremasterSecret", Cipher.SECRET_KEY); |
| 146 | } catch (Exception e) { |
| 147 | /* |
| 148 | * Bogus decrypted ClientKeyExchange? If so, conjure a |
| 149 | * a random preMaster secret that will fail later during |
| 150 | * Finished message processing. This is a countermeasure against |
| 151 | * the "interactive RSA PKCS#1 encryption envelop attack" reported |
| 152 | * in June 1998. Preserving the executation path will |
| 153 | * mitigate timing attacks and force consistent error handling |
| 154 | * that will prevent an attacking client from differentiating |
| 155 | * different kinds of decrypted ClientKeyExchange bogosities. |
| 156 | */ |
| 157 | if (debug != null && Debug.isOn("handshake")) { |
| 158 | System.out.println("Error decrypting premaster secret:"); |
| 159 | e.printStackTrace(System.out); |
| 160 | System.out.println("Generating random secret"); |
| 161 | } |
| 162 | preMaster = generateDummySecret(currentVersion); |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | // generate a premaster secret with the specified version number |
| 167 | static SecretKey generateDummySecret(ProtocolVersion version) { |
| 168 | try { |
| 169 | KeyGenerator kg = |
| 170 | JsseJce.getKeyGenerator("SunTlsRsaPremasterSecret"); |
| 171 | kg.init(new TlsRsaPremasterSecretParameterSpec |
| 172 | (version.major, version.minor)); |
| 173 | return kg.generateKey(); |
| 174 | } catch (GeneralSecurityException e) { |
| 175 | throw new RuntimeException("Could not generate dummy secret", e); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | int messageLength() { |
| 180 | if (protocolVersion.v >= ProtocolVersion.TLS10.v) { |
| 181 | return encrypted.length + 2; |
| 182 | } else { |
| 183 | return encrypted.length; |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | void send(HandshakeOutStream s) throws IOException { |
| 188 | if (protocolVersion.v >= ProtocolVersion.TLS10.v) { |
| 189 | s.putBytes16(encrypted); |
| 190 | } else { |
| 191 | s.write(encrypted); |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | void print(PrintStream s) throws IOException { |
| 196 | s.println("*** ClientKeyExchange, RSA PreMasterSecret, " + protocolVersion); |
| 197 | } |
| 198 | } |