| /* |
| * Copyright (c) 2003, 2009, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.security.ssl.krb5; |
| |
| import java.io.*; |
| import java.security.*; |
| import java.security.interfaces.*; |
| |
| import javax.net.ssl.*; |
| |
| import sun.security.krb5.EncryptionKey; |
| import sun.security.krb5.EncryptedData; |
| import sun.security.krb5.KrbException; |
| import sun.security.krb5.internal.crypto.KeyUsage; |
| |
| import sun.security.ssl.Debug; |
| import sun.security.ssl.HandshakeInStream; |
| import sun.security.ssl.HandshakeMessage; |
| import sun.security.ssl.ProtocolVersion; |
| |
| /** |
| * This is the Kerberos premaster secret in the Kerberos client key |
| * exchange message (CLIENT --> SERVER); it holds the |
| * Kerberos-encrypted pre-master secret. The secret is encrypted using the |
| * Kerberos session key. The padding and size of the resulting message |
| * depends on the session key type, but the pre-master secret is |
| * always exactly 48 bytes. |
| * |
| */ |
| final class KerberosPreMasterSecret { |
| |
| private ProtocolVersion protocolVersion; // preMaster [0,1] |
| private byte preMaster[]; // 48 bytes |
| private byte encrypted[]; |
| |
| /** |
| * Constructor used by client to generate premaster secret. |
| * |
| * Client randomly creates a pre-master secret and encrypts it |
| * using the Kerberos session key; only the server can decrypt |
| * it, using the session key available in the service ticket. |
| * |
| * @param protocolVersion used to set preMaster[0,1] |
| * @param generator random number generator for generating premaster secret |
| * @param sessionKey Kerberos session key for encrypting premaster secret |
| */ |
| KerberosPreMasterSecret(ProtocolVersion protocolVersion, |
| SecureRandom generator, EncryptionKey sessionKey) throws IOException { |
| |
| if (sessionKey.getEType() == |
| EncryptedData.ETYPE_DES3_CBC_HMAC_SHA1_KD) { |
| throw new IOException( |
| "session keys with des3-cbc-hmac-sha1-kd encryption type " + |
| "are not supported for TLS Kerberos cipher suites"); |
| } |
| |
| this.protocolVersion = protocolVersion; |
| preMaster = generatePreMaster(generator, protocolVersion); |
| |
| // Encrypt premaster secret |
| try { |
| EncryptedData eData = new EncryptedData(sessionKey, preMaster, |
| KeyUsage.KU_UNKNOWN); |
| encrypted = eData.getBytes(); // not ASN.1 encoded. |
| |
| } catch (KrbException e) { |
| throw (SSLKeyException)new SSLKeyException |
| ("Kerberos premaster secret error").initCause(e); |
| } |
| } |
| |
| /* |
| * Constructor used by server to decrypt encrypted premaster secret. |
| * The protocol version in preMaster[0,1] must match either currentVersion |
| * or clientVersion, otherwise, the premaster secret is set to |
| * a random one to foil possible attack. |
| * |
| * @param currentVersion version of protocol being used |
| * @param clientVersion version requested by client |
| * @param generator random number generator used to generate |
| * bogus premaster secret if premaster secret verification fails |
| * @param input input stream from which to read the encrypted |
| * premaster secret |
| * @param sessionKey Kerberos session key to be used for decryption |
| */ |
| KerberosPreMasterSecret(ProtocolVersion currentVersion, |
| ProtocolVersion clientVersion, |
| SecureRandom generator, HandshakeInStream input, |
| EncryptionKey sessionKey) throws IOException { |
| |
| // Extract encrypted premaster secret from message |
| encrypted = input.getBytes16(); |
| |
| if (HandshakeMessage.debug != null && Debug.isOn("handshake")) { |
| if (encrypted != null) { |
| Debug.println(System.out, |
| "encrypted premaster secret", encrypted); |
| } |
| } |
| |
| if (sessionKey.getEType() == |
| EncryptedData.ETYPE_DES3_CBC_HMAC_SHA1_KD) { |
| throw new IOException( |
| "session keys with des3-cbc-hmac-sha1-kd encryption type " + |
| "are not supported for TLS Kerberos cipher suites"); |
| } |
| |
| // Decrypt premaster secret |
| try { |
| EncryptedData data = new EncryptedData(sessionKey.getEType(), |
| null /* optional kvno */, encrypted); |
| |
| byte[] temp = data.decrypt(sessionKey, KeyUsage.KU_UNKNOWN); |
| if (HandshakeMessage.debug != null && Debug.isOn("handshake")) { |
| if (encrypted != null) { |
| Debug.println(System.out, |
| "decrypted premaster secret", temp); |
| } |
| } |
| |
| // Reset data stream after decryption, remove redundant bytes |
| preMaster = data.reset(temp, false); |
| |
| protocolVersion = ProtocolVersion.valueOf(preMaster[0], |
| preMaster[1]); |
| if (HandshakeMessage.debug != null && Debug.isOn("handshake")) { |
| System.out.println("Kerberos PreMasterSecret version: " |
| + protocolVersion); |
| } |
| } catch (Exception e) { |
| // catch exception & process below |
| preMaster = null; |
| protocolVersion = currentVersion; |
| } |
| |
| // check if the premaster secret version is ok |
| // the specification says that it must be the maximum version supported |
| // by the client from its ClientHello message. However, many |
| // implementations send the negotiated version, so accept both |
| // NOTE that we may be comparing two unsupported version numbers in |
| // the second case, which is why we cannot use object references |
| // equality in this special case |
| boolean versionMismatch = (protocolVersion != currentVersion) && |
| (protocolVersion.v != clientVersion.v); |
| |
| |
| /* |
| * Bogus decrypted ClientKeyExchange? If so, conjure a |
| * a random preMaster secret that will fail later during |
| * Finished message processing. This is a countermeasure against |
| * the "interactive RSA PKCS#1 encryption envelop attack" reported |
| * in June 1998. Preserving the executation path will |
| * mitigate timing attacks and force consistent error handling |
| * that will prevent an attacking client from differentiating |
| * different kinds of decrypted ClientKeyExchange bogosities. |
| */ |
| if ((preMaster == null) || (preMaster.length != 48) |
| || versionMismatch) { |
| if (HandshakeMessage.debug != null && Debug.isOn("handshake")) { |
| System.out.println("Kerberos PreMasterSecret error, " |
| + "generating random secret"); |
| if (preMaster != null) { |
| Debug.println(System.out, "Invalid secret", preMaster); |
| } |
| } |
| preMaster = generatePreMaster(generator, currentVersion); |
| protocolVersion = currentVersion; |
| } |
| } |
| |
| /* |
| * Used by server to generate premaster secret in case of |
| * problem decoding ticket. |
| * |
| * @param protocolVersion used for preMaster[0,1] |
| * @param generator random number generator to use for generating secret. |
| */ |
| KerberosPreMasterSecret(ProtocolVersion protocolVersion, |
| SecureRandom generator) { |
| |
| this.protocolVersion = protocolVersion; |
| preMaster = generatePreMaster(generator, protocolVersion); |
| } |
| |
| private static byte[] generatePreMaster(SecureRandom rand, |
| ProtocolVersion ver) { |
| |
| byte[] pm = new byte[48]; |
| rand.nextBytes(pm); |
| pm[0] = ver.major; |
| pm[1] = ver.minor; |
| |
| return pm; |
| } |
| |
| // Clone not needed; internal use only |
| byte[] getUnencrypted() { |
| return preMaster; |
| } |
| |
| // Clone not needed; internal use only |
| byte[] getEncrypted() { |
| return encrypted; |
| } |
| } |
