/* * Copyright (c) 2003, 2010, 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.util.Arrays; 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); } } // Remove padding bytes after decryption. Only DES and DES3 have // paddings and we don't support DES3 in TLS (see above) if (temp.length == 52 && data.getEType() == EncryptedData.ETYPE_DES_CBC_CRC) { // For des-cbc-crc, 4 paddings. Value can be 0x04 or 0x00. if (paddingByteIs(temp, 52, (byte)4) || paddingByteIs(temp, 52, (byte)0)) { temp = Arrays.copyOf(temp, 48); } } else if (temp.length == 56 && data.getEType() == EncryptedData.ETYPE_DES_CBC_MD5) { // For des-cbc-md5, 8 paddings with 0x08, or no padding if (paddingByteIs(temp, 56, (byte)8)) { temp = Arrays.copyOf(temp, 48); } } preMaster = temp; 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 // old implementations send the negotiated version, so accept both // for SSL v3.0 and TLS v1.0. // 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.v != clientVersion.v); /* * we never checked the client_version in server side * for TLS v1.0 and SSL v3.0. For compatibility, we * maintain this behavior. */ if (versionMismatch && (clientVersion.v <= 0x0301)) { versionMismatch = (protocolVersion.v != currentVersion.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); } } /* * Randomize the preMaster secret with the * ClientHello.client_version, as will produce invalid master * secret to prevent the attacks. */ preMaster = generatePreMaster(generator, clientVersion); protocolVersion = clientVersion; } } /** * Checks if all paddings of data are b * @param data the block with padding * @param len length of data, >= 48 * @param b expected padding byte */ private static boolean paddingByteIs(byte[] data, int len, byte b) { for (int i=48; i<len; i++) { if (data[i] != b) return false; } return true; } /* * 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; }}
/*
* Copyright (c) 2003, 2010, 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.util.Arrays;
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);
}
}
// Remove padding bytes after decryption. Only DES and DES3 have
// paddings and we don't support DES3 in TLS (see above)
if (temp.length == 52 &&
data.getEType() == EncryptedData.ETYPE_DES_CBC_CRC) {
// For des-cbc-crc, 4 paddings. Value can be 0x04 or 0x00.
if (paddingByteIs(temp, 52, (byte)4) ||
paddingByteIs(temp, 52, (byte)0)) {
temp = Arrays.copyOf(temp, 48);
}
} else if (temp.length == 56 &&
data.getEType() == EncryptedData.ETYPE_DES_CBC_MD5) {
// For des-cbc-md5, 8 paddings with 0x08, or no padding
if (paddingByteIs(temp, 56, (byte)8)) {
temp = Arrays.copyOf(temp, 48);
}
}
preMaster = temp;
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
// old implementations send the negotiated version, so accept both
// for SSL v3.0 and TLS v1.0.
// 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.v != clientVersion.v);
/*
* we never checked the client_version in server side
* for TLS v1.0 and SSL v3.0. For compatibility, we
* maintain this behavior.
*/
if (versionMismatch && (clientVersion.v <= 0x0301)) {
versionMismatch = (protocolVersion.v != currentVersion.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);
}
}
/*
* Randomize the preMaster secret with the
* ClientHello.client_version, as will produce invalid master
* secret to prevent the attacks.
*/
preMaster = generatePreMaster(generator, clientVersion);
protocolVersion = clientVersion;
}
}
/**
* Checks if all paddings of data are b
* @param data the block with padding
* @param len length of data, >= 48
* @param b expected padding byte
*/
private static boolean paddingByteIs(byte[] data, int len, byte b) {
for (int i=48; i<len; i++) {
if (data[i] != b) return false;
}
return true;
}
/*
* 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;
}
}