/*
* Copyright (c) 1996, 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
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*/
package sun.security.ssl;
import java.io.*;
import java.util.*;
import java.security.*;
import java.security.cert.*;
import java.security.interfaces.*;
import java.security.spec.ECParameterSpec;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.net.ssl.*;
import javax.security.auth.Subject;
import javax.security.auth.kerberos.KerberosKey;
import javax.security.auth.kerberos.KerberosPrincipal;
import javax.security.auth.kerberos.ServicePermission;
import sun.security.jgss.krb5.Krb5Util;
import sun.security.jgss.GSSUtil;
import com.sun.net.ssl.internal.ssl.X509ExtendedTrustManager;
import sun.security.ssl.HandshakeMessage.*;
import sun.security.ssl.CipherSuite.*;
import static sun.security.ssl.CipherSuite.*;
import static sun.security.ssl.CipherSuite.KeyExchange.*;
/**
* ServerHandshaker does the protocol handshaking from the point
* of view of a server. It is driven asychronously by handshake messages
* as delivered by the parent Handshaker class, and also uses
* common functionality (e.g. key generation) that is provided there.
*
* @author David Brownell
*/
final class ServerHandshaker extends Handshaker {
// is the server going to require the client to authenticate?
private byte doClientAuth;
// our authentication info
private X509Certificate[] certs;
private PrivateKey privateKey;
private KerberosKey[] kerberosKeys;
// flag to check for clientCertificateVerify message
private boolean needClientVerify = false;
/*
* For exportable ciphersuites using non-exportable key sizes, we use
* ephemeral RSA keys. We could also do anonymous RSA in the same way
* but there are no such ciphersuites currently defined.
*/
private PrivateKey tempPrivateKey;
private PublicKey tempPublicKey;
/*
* For anonymous and ephemeral Diffie-Hellman key exchange, we use
* ephemeral Diffie-Hellman keys.
*/
private DHCrypt dh;
// Helper for ECDH based key exchanges
private ECDHCrypt ecdh;
// version request by the client in its ClientHello
// we remember it for the RSA premaster secret version check
private ProtocolVersion clientRequestedVersion;
private SupportedEllipticCurvesExtension supportedCurves;
/*
* Constructor ... use the keys found in the auth context.
*/
ServerHandshaker(SSLSocketImpl socket, SSLContextImpl context,
ProtocolList enabledProtocols, byte clientAuth,
ProtocolVersion activeProtocolVersion, boolean isInitialHandshake,
boolean secureRenegotiation,
byte[] clientVerifyData, byte[] serverVerifyData) {
super(socket, context, enabledProtocols,
(clientAuth != SSLEngineImpl.clauth_none), false,
activeProtocolVersion, isInitialHandshake, secureRenegotiation,
clientVerifyData, serverVerifyData);
doClientAuth = clientAuth;
}
/*
* Constructor ... use the keys found in the auth context.
*/
ServerHandshaker(SSLEngineImpl engine, SSLContextImpl context,
ProtocolList enabledProtocols, byte clientAuth,
ProtocolVersion activeProtocolVersion,
boolean isInitialHandshake, boolean secureRenegotiation,
byte[] clientVerifyData, byte[] serverVerifyData) {
super(engine, context, enabledProtocols,
(clientAuth != SSLEngineImpl.clauth_none), false,
activeProtocolVersion, isInitialHandshake, secureRenegotiation,
clientVerifyData, serverVerifyData);
doClientAuth = clientAuth;
}
/*
* As long as handshaking has not started, we can change
* whether client authentication is required. Otherwise,
* we will need to wait for the next handshake.
*/
void setClientAuth(byte clientAuth) {
doClientAuth = clientAuth;
}
/*
* This routine handles all the server side handshake messages, one at
* a time. Given the message type (and in some cases the pending cipher
* spec) it parses the type-specific message. Then it calls a function
* that handles that specific message.
*
* It updates the state machine as each message is processed, and writes
* responses as needed using the connection in the constructor.
*/
void processMessage(byte type, int message_len)
throws IOException {
//
// In SSLv3 and TLS, messages follow strictly increasing
// numerical order _except_ for one annoying special case.
//
if ((state > type)
&& (state != HandshakeMessage.ht_client_key_exchange
&& type != HandshakeMessage.ht_certificate_verify)) {
throw new SSLProtocolException(
"Handshake message sequence violation, state = " + state
+ ", type = " + type);
}
switch (type) {
case HandshakeMessage.ht_client_hello:
ClientHello ch = new ClientHello(input, message_len);
/*
* send it off for processing.
*/
this.clientHello(ch);
break;
case HandshakeMessage.ht_certificate:
if (doClientAuth == SSLEngineImpl.clauth_none) {
fatalSE(Alerts.alert_unexpected_message,
"client sent unsolicited cert chain");
// NOTREACHED
}
this.clientCertificate(new CertificateMsg(input));
break;
case HandshakeMessage.ht_client_key_exchange:
SecretKey preMasterSecret;
switch (keyExchange) {
case K_RSA:
case K_RSA_EXPORT:
/*
* The client's pre-master secret is decrypted using
* either the server's normal private RSA key, or the
* temporary one used for non-export or signing-only
* certificates/keys.
*/
RSAClientKeyExchange pms = new RSAClientKeyExchange
(protocolVersion, input, message_len, privateKey);
preMasterSecret = this.clientKeyExchange(pms);
break;
case K_KRB5:
case K_KRB5_EXPORT:
preMasterSecret = this.clientKeyExchange(
new KerberosClientKeyExchange(protocolVersion,
clientRequestedVersion,
sslContext.getSecureRandom(),
input,
kerberosKeys));
break;
case K_DHE_RSA:
case K_DHE_DSS:
case K_DH_ANON:
/*
* The pre-master secret is derived using the normal
* Diffie-Hellman calculation. Note that the main
* protocol difference in these five flavors is in how
* the ServerKeyExchange message was constructed!
*/
preMasterSecret = this.clientKeyExchange(
new DHClientKeyExchange(input));
break;
case K_ECDH_RSA:
case K_ECDH_ECDSA:
case K_ECDHE_RSA:
case K_ECDHE_ECDSA:
case K_ECDH_ANON:
preMasterSecret = this.clientKeyExchange
(new ECDHClientKeyExchange(input));
break;
default:
throw new SSLProtocolException
("Unrecognized key exchange: " + keyExchange);
}
//
// All keys are calculated from the premaster secret
// and the exchanged nonces in the same way.
//
calculateKeys(preMasterSecret, clientRequestedVersion);
break;
case HandshakeMessage.ht_certificate_verify:
this.clientCertificateVerify(new CertificateVerify(input));
break;
case HandshakeMessage.ht_finished:
this.clientFinished(new Finished(protocolVersion, input));
break;
default:
throw new SSLProtocolException(
"Illegal server handshake msg, " + type);
}
//
// Move the state machine forward except for that annoying
// special case. This means that clients could send extra
// cert verify messages; not a problem so long as all of
// them actually check out.
//
if (state < type && type != HandshakeMessage.ht_certificate_verify) {
state = type;
}
}
/*
* ClientHello presents the server with a bunch of options, to which the
* server replies with a ServerHello listing the ones which this session
* will use. If needed, it also writes its Certificate plus in some cases
* a ServerKeyExchange message. It may also write a CertificateRequest,
* to elicit a client certificate.
*
* All these messages are terminated by a ServerHelloDone message. In
* most cases, all this can be sent in a single Record.
*/
private void clientHello(ClientHello mesg) throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
// Does the message include security renegotiation indication?
boolean renegotiationIndicated = false;
// check the TLS_EMPTY_RENEGOTIATION_INFO_SCSV
CipherSuiteList cipherSuites = mesg.getCipherSuites();
if (cipherSuites.contains(CipherSuite.C_SCSV)) {
renegotiationIndicated = true;
if (isInitialHandshake) {
secureRenegotiation = true;
} else {
// abort the handshake with a fatal handshake_failure alert
if (secureRenegotiation) {
fatalSE(Alerts.alert_handshake_failure,
"The SCSV is present in a secure renegotiation");
} else {
fatalSE(Alerts.alert_handshake_failure,
"The SCSV is present in a insecure renegotiation");
}
}
}
// check the "renegotiation_info" extension
RenegotiationInfoExtension clientHelloRI = (RenegotiationInfoExtension)
mesg.extensions.get(ExtensionType.EXT_RENEGOTIATION_INFO);
if (clientHelloRI != null) {
renegotiationIndicated = true;
if (isInitialHandshake) {
// verify the length of the "renegotiated_connection" field
if (!clientHelloRI.isEmpty()) {
// abort the handshake with a fatal handshake_failure alert
fatalSE(Alerts.alert_handshake_failure,
"The renegotiation_info field is not empty");
}
secureRenegotiation = true;
} else {
if (!secureRenegotiation) {
// unexpected RI extension for insecure renegotiation,
// abort the handshake with a fatal handshake_failure alert
fatalSE(Alerts.alert_handshake_failure,
"The renegotiation_info is present in a insecure " +
"renegotiation");
}
// verify the client_verify_data value
if (!Arrays.equals(clientVerifyData,
clientHelloRI.getRenegotiatedConnection())) {
fatalSE(Alerts.alert_handshake_failure,
"Incorrect verify date in ClientHello " +
"renegotiation_info message");
}
}
} else if (!isInitialHandshake && secureRenegotiation) {
// if the connection's "secure_renegotiation" flag is set to TRUE
// and the "renegotiation_info" extension is not present, abort
// the handshake.
fatalSE(Alerts.alert_handshake_failure,
"Inconsistent secure renegotiation indication");
}
// if there is no security renegotiation indication or the previous
// handshake is insecure.
if (!renegotiationIndicated || !secureRenegotiation) {
if (isInitialHandshake) {
if (!allowLegacyHelloMessages) {
// abort the handshake with a fatal handshake_failure alert
fatalSE(Alerts.alert_handshake_failure,
"Failed to negotiate the use of secure renegotiation");
}
// continue with legacy ClientHello
if (debug != null && Debug.isOn("handshake")) {
System.out.println("Warning: No renegotiation " +
"indication in ClientHello, allow legacy ClientHello");
}
} else if (!allowUnsafeRenegotiation) {
// abort the handshake
if (activeProtocolVersion.v >= ProtocolVersion.TLS10.v) {
// response with a no_renegotiation warning,
warningSE(Alerts.alert_no_renegotiation);
// invalidate the handshake so that the caller can
// dispose this object.
invalidated = true;
// If there is still unread block in the handshake
// input stream, it would be truncated with the disposal
// and the next handshake message will become incomplete.
//
// However, according to SSL/TLS specifications, no more
// handshake message could immediately follow ClientHello
// or HelloRequest. But in case of any improper messages,
// we'd better check to ensure there is no remaining bytes
// in the handshake input stream.
if (input.available() > 0) {
fatalSE(Alerts.alert_unexpected_message,
"ClientHello followed by an unexpected " +
"handshake message");
}
return;
} else {
// For SSLv3, send the handshake_failure fatal error.
// Note that SSLv3 does not define a no_renegotiation
// alert like TLSv1. However we cannot ignore the message
// simply, otherwise the other side was waiting for a
// response that would never come.
fatalSE(Alerts.alert_handshake_failure,
"Renegotiation is not allowed");
}
} else { // !isInitialHandshake && allowUnsafeRenegotiation
// continue with unsafe renegotiation.
if (debug != null && Debug.isOn("handshake")) {
System.out.println(
"Warning: continue with insecure renegotiation");
}
}
}
/*
* Always make sure this entire record has been digested before we
* start emitting output, to ensure correct digesting order.
*/
input.digestNow();
/*
* FIRST, construct the ServerHello using the options and priorities
* from the ClientHello. Update the (pending) cipher spec as we do
* so, and save the client's version to protect against rollback
* attacks.
*
* There are a bunch of minor tasks here, and one major one: deciding
* if the short or the full handshake sequence will be used.
*/
ServerHello m1 = new ServerHello();
clientRequestedVersion = mesg.protocolVersion;
// check if clientVersion is recent enough for us
if (clientRequestedVersion.v < enabledProtocols.min.v) {
fatalSE(Alerts.alert_handshake_failure,
"Client requested protocol " + clientRequestedVersion +
" not enabled or not supported");
}
// now we know we have an acceptable version
// use the lower of our max and the client requested version
ProtocolVersion selectedVersion;
if (clientRequestedVersion.v <= enabledProtocols.max.v) {
selectedVersion = clientRequestedVersion;
} else {
selectedVersion = enabledProtocols.max;
}
setVersion(selectedVersion);
m1.protocolVersion = protocolVersion;
//
// random ... save client and server values for later use
// in computing the master secret (from pre-master secret)
// and thence the other crypto keys.
//
// NOTE: this use of three inputs to generating _each_ set
// of ciphers slows things down, but it does increase the
// security since each connection in the session can hold
// its own authenticated (and strong) keys. One could make
// creation of a session a rare thing...
//
clnt_random = mesg.clnt_random;
svr_random = new RandomCookie(sslContext.getSecureRandom());
m1.svr_random = svr_random;
session = null; // forget about the current session
//
// Here we go down either of two paths: (a) the fast one, where
// the client's asked to rejoin an existing session, and the server
// permits this; (b) the other one, where a new session is created.
//
if (mesg.sessionId.length() != 0) {
// client is trying to resume a session, let's see...
SSLSessionImpl previous = ((SSLSessionContextImpl)sslContext
.engineGetServerSessionContext())
.get(mesg.sessionId.getId());
//
// Check if we can use the fast path, resuming a session. We
// can do so iff we have a valid record for that session, and
// the cipher suite for that session was on the list which the
// client requested, and if we're not forgetting any needed
// authentication on the part of the client.
//
if (previous != null) {
resumingSession = previous.isRejoinable();
if (resumingSession) {
ProtocolVersion oldVersion = previous.getProtocolVersion();
// cannot resume session with different version
if (oldVersion != protocolVersion) {
resumingSession = false;
}
}
if (resumingSession &&
(doClientAuth == SSLEngineImpl.clauth_required)) {
try {
previous.getPeerPrincipal();
} catch (SSLPeerUnverifiedException e) {
resumingSession = false;
}
}
// validate subject identity
if (resumingSession) {
CipherSuite suite = previous.getSuite();
if (suite.keyExchange == K_KRB5 ||
suite.keyExchange == K_KRB5_EXPORT) {
Principal localPrincipal = previous.getLocalPrincipal();
Subject subject = null;
try {
subject = AccessController.doPrivileged(
new PrivilegedExceptionAction<Subject>() {
public Subject run() throws Exception {
return Krb5Util.getSubject(
GSSUtil.CALLER_SSL_SERVER,
getAccSE());
}});
} catch (PrivilegedActionException e) {
subject = null;
if (debug != null && Debug.isOn("session")) {
System.out.println("Attempt to obtain" +
" subject failed!");
}
}
if (subject != null) {
Set<KerberosPrincipal> principals =
subject.getPrincipals(KerberosPrincipal.class);
if (!principals.contains(localPrincipal)) {
resumingSession = false;
if (debug != null && Debug.isOn("session")) {
System.out.println("Subject identity" +
" is not the same");
}
} else {
if (debug != null && Debug.isOn("session"))
System.out.println("Subject identity" +
" is same");
}
} else {
resumingSession = false;
if (debug != null && Debug.isOn("session"))
System.out.println("Kerberos credentials are" +
" not present in the current Subject;" +
" check if " +
" javax.security.auth.useSubjectAsCreds" +
" system property has been set to false");
}
}
}
if (resumingSession) {
CipherSuite suite = previous.getSuite();
// verify that the ciphersuite from the cached session
// is in the list of client requested ciphersuites and
// we have it enabled
if ((isNegotiable(suite) == false) ||
(mesg.getCipherSuites().contains(suite) == false)) {
resumingSession = false;
} else {
// everything looks ok, set the ciphersuite
// this should be done last when we are sure we
// will resume
setCipherSuite(suite);
}
}
if (resumingSession) {
session = previous;
if (debug != null &&
(Debug.isOn("handshake") || Debug.isOn("session"))) {
System.out.println("%% Resuming " + session);
}
}
}
} // else client did not try to resume
//
// If client hasn't specified a session we can resume, start a
// new one and choose its cipher suite and compression options.
// Unless new session creation is disabled for this connection!
//
if (session == null) {
if (!enableNewSession) {
throw new SSLException("Client did not resume a session");
}
supportedCurves = (SupportedEllipticCurvesExtension)
mesg.extensions.get(ExtensionType.EXT_ELLIPTIC_CURVES);
chooseCipherSuite(mesg);
session = new SSLSessionImpl(protocolVersion, cipherSuite,
sslContext.getSecureRandom(),
getHostAddressSE(), getPortSE());
session.setLocalPrivateKey(privateKey);
// chooseCompression(mesg);
}
m1.cipherSuite = cipherSuite;
m1.sessionId = session.getSessionId();
m1.compression_method = session.getCompression();
if (secureRenegotiation) {
// For ServerHellos that are initial handshakes, then the
// "renegotiated_connection" field in "renegotiation_info"
// extension is of zero length.
//
// For ServerHellos that are renegotiating, this field contains
// the concatenation of client_verify_data and server_verify_data.
//
// Note that for initial handshakes, both the clientVerifyData
// variable and serverVerifyData variable are of zero length.
HelloExtension serverHelloRI = new RenegotiationInfoExtension(
clientVerifyData, serverVerifyData);
m1.extensions.add(serverHelloRI);
}
if (debug != null && Debug.isOn("handshake")) {
m1.print(System.out);
System.out.println("Cipher suite: " + session.getSuite());
}
m1.write(output);
//
// If we are resuming a session, we finish writing handshake
// messages right now and then finish.
//
if (resumingSession) {
calculateConnectionKeys(session.getMasterSecret());
sendChangeCipherAndFinish(false);
return;
}
/*
* SECOND, write the server Certificate(s) if we need to.
*
* NOTE: while an "anonymous RSA" mode is explicitly allowed by
* the protocol, we can't support it since all of the SSL flavors
* defined in the protocol spec are explicitly stated to require
* using RSA certificates.
*/
if (keyExchange == K_KRB5 || keyExchange == K_KRB5_EXPORT) {
// Server certificates are omitted for Kerberos ciphers
} else if ((keyExchange != K_DH_ANON) && (keyExchange != K_ECDH_ANON)) {
if (certs == null) {
throw new RuntimeException("no certificates");
}
CertificateMsg m2 = new CertificateMsg(certs);
/*
* Set local certs in the SSLSession, output
* debug info, and then actually write to the client.
*/
session.setLocalCertificates(certs);
if (debug != null && Debug.isOn("handshake")) {
m2.print(System.out);
}
m2.write(output);
// XXX has some side effects with OS TCP buffering,
// leave it out for now
// let client verify chain in the meantime...
// output.flush();
} else {
if (certs != null) {
throw new RuntimeException("anonymous keyexchange with certs");
}
}
/*
* THIRD, the ServerKeyExchange message ... iff it's needed.
*
* It's usually needed unless there's an encryption-capable
* RSA cert, or a D-H cert. The notable exception is that
* exportable ciphers used with big RSA keys need to downgrade
* to use short RSA keys, even when the key/cert encrypts OK.
*/
ServerKeyExchange m3;
switch (keyExchange) {
case K_RSA:
case K_KRB5:
case K_KRB5_EXPORT:
// no server key exchange for RSA or KRB5 ciphersuites
m3 = null;
break;
case K_RSA_EXPORT:
if (JsseJce.getRSAKeyLength(certs[0].getPublicKey()) > 512) {
try {
m3 = new RSA_ServerKeyExchange(
tempPublicKey, privateKey,
clnt_random, svr_random,
sslContext.getSecureRandom());
privateKey = tempPrivateKey;
} catch (GeneralSecurityException e) {
throwSSLException
("Error generating RSA server key exchange", e);
m3 = null; // make compiler happy
}
} else {
// RSA_EXPORT with short key, don't need ServerKeyExchange
m3 = null;
}
break;
case K_DHE_RSA:
case K_DHE_DSS:
try {
m3 = new DH_ServerKeyExchange(dh,
privateKey,
clnt_random.random_bytes,
svr_random.random_bytes,
sslContext.getSecureRandom());
} catch (GeneralSecurityException e) {
throwSSLException("Error generating DH server key exchange", e);
m3 = null; // make compiler happy
}
break;
case K_DH_ANON:
m3 = new DH_ServerKeyExchange(dh);
break;
case K_ECDHE_RSA:
case K_ECDHE_ECDSA:
case K_ECDH_ANON:
try {
m3 = new ECDH_ServerKeyExchange(ecdh,
privateKey,
clnt_random.random_bytes,
svr_random.random_bytes,
sslContext.getSecureRandom());
} catch (GeneralSecurityException e) {
throwSSLException("Error generating ECDH server key exchange", e);
m3 = null; // make compiler happy
}
break;
case K_ECDH_RSA:
case K_ECDH_ECDSA:
// ServerKeyExchange not used for fixed ECDH
m3 = null;
break;
default:
throw new RuntimeException("internal error: " + keyExchange);
}
if (m3 != null) {
if (debug != null && Debug.isOn("handshake")) {
m3.print(System.out);
}
m3.write(output);
}
//
// FOURTH, the CertificateRequest message. The details of
// the message can be affected by the key exchange algorithm
// in use. For example, certs with fixed Diffie-Hellman keys
// are only useful with the DH_DSS and DH_RSA key exchange
// algorithms.
//
// Needed only if server requires client to authenticate self.
// Illegal for anonymous flavors, so we need to check that.
//
if (keyExchange == K_KRB5 || keyExchange == K_KRB5_EXPORT) {
// CertificateRequest is omitted for Kerberos ciphers
} else if (doClientAuth != SSLEngineImpl.clauth_none &&
keyExchange != K_DH_ANON && keyExchange != K_ECDH_ANON) {
CertificateRequest m4;
X509Certificate caCerts[];
caCerts = sslContext.getX509TrustManager().getAcceptedIssuers();
m4 = new CertificateRequest(caCerts, keyExchange);
if (debug != null && Debug.isOn("handshake")) {
m4.print(System.out);
}
m4.write(output);
}
/*
* FIFTH, say ServerHelloDone.
*/
ServerHelloDone m5 = new ServerHelloDone();
if (debug != null && Debug.isOn("handshake")) {
m5.print(System.out);
}
m5.write(output);
/*
* Flush any buffered messages so the client will see them.
* Ideally, all the messages above go in a single network level
* message to the client. Without big Certificate chains, it's
* going to be the common case.
*/
output.flush();
}
/*
* Choose cipher suite from among those supported by client. Sets
* the cipherSuite and keyExchange variables.
*/
private void chooseCipherSuite(ClientHello mesg) throws IOException {
for (CipherSuite suite : mesg.getCipherSuites().collection()) {
if (isNegotiable(suite) == false) {
continue;
}
if (doClientAuth == SSLEngineImpl.clauth_required) {
if ((suite.keyExchange == K_DH_ANON) ||
(suite.keyExchange == K_ECDH_ANON)) {
continue;
}
}
if (trySetCipherSuite(suite) == false) {
continue;
}
return;
}
fatalSE(Alerts.alert_handshake_failure,
"no cipher suites in common");
}
/**
* Set the given CipherSuite, if possible. Return the result.
* The call succeeds if the CipherSuite is available and we have
* the necessary certificates to complete the handshake. We don't
* check if the CipherSuite is actually enabled.
*
* If successful, this method also generates ephemeral keys if
* required for this ciphersuite. This may take some time, so this
* method should only be called if you really want to use the
* CipherSuite.
*
* This method is called from chooseCipherSuite() in this class
* and SSLServerSocketImpl.checkEnabledSuites() (as a sanity check).
*/
boolean trySetCipherSuite(CipherSuite suite) {
/*
* If we're resuming a session we know we can
* support this key exchange algorithm and in fact
* have already cached the result of it in
* the session state.
*/
if (resumingSession) {
return true;
}
if (suite.isNegotiable() == false) {
return false;
}
KeyExchange keyExchange = suite.keyExchange;
// null out any existing references
privateKey = null;
certs = null;
dh = null;
tempPrivateKey = null;
tempPublicKey = null;
switch (keyExchange) {
case K_RSA:
case K_RSA_EXPORT:
case K_DHE_RSA:
case K_ECDHE_RSA:
// need RSA certs for authentication
if (setupPrivateKeyAndChain("RSA") == false) {
return false;
}
if (keyExchange == K_RSA_EXPORT) {
try {
if (JsseJce.getRSAKeyLength(certs[0].getPublicKey()) > 512) {
if (!setupEphemeralRSAKeys(suite.exportable)) {
return false;
}
}
} catch (RuntimeException e) {
// could not determine keylength, ignore key
return false;
}
} else if (keyExchange == K_DHE_RSA) {
setupEphemeralDHKeys(suite.exportable);
} else if (keyExchange == K_ECDHE_RSA) {
if (setupEphemeralECDHKeys() == false) {
return false;
}
} // else nothing more to do for K_RSA
break;
case K_DHE_DSS:
// need DSS certs for authentication
if (setupPrivateKeyAndChain("DSA") == false) {
return false;
}
setupEphemeralDHKeys(suite.exportable);
break;
case K_ECDHE_ECDSA:
// need EC cert signed using EC
if (setupPrivateKeyAndChain("EC_EC") == false) {
return false;
}
if (setupEphemeralECDHKeys() == false) {
return false;
}
break;
case K_ECDH_RSA:
// need EC cert signed using RSA
if (setupPrivateKeyAndChain("EC_RSA") == false) {
return false;
}
setupStaticECDHKeys();
break;
case K_ECDH_ECDSA:
// need EC cert signed using EC
if (setupPrivateKeyAndChain("EC_EC") == false) {
return false;
}
setupStaticECDHKeys();
break;
case K_KRB5:
case K_KRB5_EXPORT:
// need Kerberos Key
if (!setupKerberosKeys()) {
return false;
}
break;
case K_DH_ANON:
// no certs needed for anonymous
setupEphemeralDHKeys(suite.exportable);
break;
case K_ECDH_ANON:
// no certs needed for anonymous
if (setupEphemeralECDHKeys() == false) {
return false;
}
break;
default:
// internal error, unknown key exchange
throw new RuntimeException("Unrecognized cipherSuite: " + suite);
}
setCipherSuite(suite);
return true;
}
/*
* Get some "ephemeral" RSA keys for this context. This means
* generating them if it's not already been done.
*
* Note that we currently do not implement any ciphersuites that use
* strong ephemeral RSA. (We do not support the EXPORT1024 ciphersuites
* and standard RSA ciphersuites prohibit ephemeral mode for some reason)
* This means that export is always true and 512 bit keys are generated.
*/
private boolean setupEphemeralRSAKeys(boolean export) {
KeyPair kp = sslContext.getEphemeralKeyManager().
getRSAKeyPair(export, sslContext.getSecureRandom());
if (kp == null) {
return false;
} else {
tempPublicKey = kp.getPublic();
tempPrivateKey = kp.getPrivate();
return true;
}
}
/*
* Acquire some "ephemeral" Diffie-Hellman keys for this handshake.
* We don't reuse these, for improved forward secrecy.
*/
private void setupEphemeralDHKeys(boolean export) {
/*
* Diffie-Hellman keys ... we use 768 bit private keys due
* to the "use twice as many key bits as bits you want secret"
* rule of thumb, assuming we want the same size premaster
* secret with Diffie-Hellman and RSA key exchanges. Except
* that exportable ciphers max out at 512 bits modulus values.
*/
dh = new DHCrypt((export ? 512 : 768), sslContext.getSecureRandom());
}
// Setup the ephemeral ECDH parameters.
// If we cannot continue because we do not support any of the curves that
// the client requested, return false. Otherwise (all is well), return true.
private boolean setupEphemeralECDHKeys() {
int index = -1;
if (supportedCurves != null) {
// if the client sent the supported curves extension, pick the
// first one that we support;
for (int curveId : supportedCurves.curveIds()) {
if (SupportedEllipticCurvesExtension.isSupported(curveId)) {
index = curveId;
break;
}
}
if (index < 0) {
// no match found, cannot use this ciphersuite
return false;
}
} else {
// pick our preference
index = SupportedEllipticCurvesExtension.DEFAULT.curveIds()[0];
}
String oid = SupportedEllipticCurvesExtension.getCurveOid(index);
ecdh = new ECDHCrypt(oid, sslContext.getSecureRandom());
return true;
}
private void setupStaticECDHKeys() {
// don't need to check whether the curve is supported, already done
// in setupPrivateKeyAndChain().
ecdh = new ECDHCrypt(privateKey, certs[0].getPublicKey());
}
/**
* Retrieve the server key and certificate for the specified algorithm
* from the KeyManager and set the instance variables.
*
* @return true if successful, false if not available or invalid
*/
private boolean setupPrivateKeyAndChain(String algorithm) {
X509ExtendedKeyManager km = sslContext.getX509KeyManager();
String alias;
if (conn != null) {
alias = km.chooseServerAlias(algorithm, null, conn);
} else {
alias = km.chooseEngineServerAlias(algorithm, null, engine);
}
if (alias == null) {
return false;
}
PrivateKey tempPrivateKey = km.getPrivateKey(alias);
if (tempPrivateKey == null) {
return false;
}
X509Certificate[] tempCerts = km.getCertificateChain(alias);
if ((tempCerts == null) || (tempCerts.length == 0)) {
return false;
}
String keyAlgorithm = algorithm.split("_")[0];
PublicKey publicKey = tempCerts[0].getPublicKey();
if ((tempPrivateKey.getAlgorithm().equals(keyAlgorithm) == false)
|| (publicKey.getAlgorithm().equals(keyAlgorithm) == false)) {
return false;
}
// For ECC certs, check whether we support the EC domain parameters.
// If the client sent a SupportedEllipticCurves ClientHello extension,
// check against that too.
if (keyAlgorithm.equals("EC")) {
if (publicKey instanceof ECPublicKey == false) {
return false;
}
ECParameterSpec params = ((ECPublicKey)publicKey).getParams();
int index = SupportedEllipticCurvesExtension.getCurveIndex(params);
if (SupportedEllipticCurvesExtension.isSupported(index) == false) {
return false;
}
if ((supportedCurves != null) && !supportedCurves.contains(index)) {
return false;
}
}
this.privateKey = tempPrivateKey;
this.certs = tempCerts;
return true;
}
/**
* Retrieve the Kerberos key for the specified server principal
* from the JAAS configuration file.
*
* @return true if successful, false if not available or invalid
*/
private boolean setupKerberosKeys() {
if (kerberosKeys != null) {
return true;
}
try {
final AccessControlContext acc = getAccSE();
kerberosKeys = AccessController.doPrivileged(
new PrivilegedExceptionAction<KerberosKey[]>() {
public KerberosKey[] run() throws Exception {
// get kerberos key for the default principal
return Krb5Util.getKeys(
GSSUtil.CALLER_SSL_SERVER, null, acc);
}});
// check permission to access and use the secret key of the
// Kerberized "host" service
if (kerberosKeys != null) {
if (debug != null && Debug.isOn("handshake")) {
System.out.println("Using Kerberos key: " +
kerberosKeys[0]);
}
String serverPrincipal =
kerberosKeys[0].getPrincipal().getName();
SecurityManager sm = System.getSecurityManager();
try {
if (sm != null) {
sm.checkPermission(new ServicePermission(serverPrincipal,
"accept"), acc);
}
} catch (SecurityException se) {
kerberosKeys = null;
// %%% destroy keys? or will that affect Subject?
if (debug != null && Debug.isOn("handshake"))
System.out.println("Permission to access Kerberos"
+ " secret key denied");
return false;
}
}
return (kerberosKeys != null);
} catch (PrivilegedActionException e) {
// Likely exception here is LoginExceptin
if (debug != null && Debug.isOn("handshake")) {
System.out.println("Attempt to obtain Kerberos key failed: "
+ e.toString());
}
return false;
}
}
/*
* For Kerberos ciphers, the premaster secret is encrypted using
* the session key. See RFC 2712.
*/
private SecretKey clientKeyExchange(KerberosClientKeyExchange mesg)
throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
// Record the principals involved in exchange
session.setPeerPrincipal(mesg.getPeerPrincipal());
session.setLocalPrincipal(mesg.getLocalPrincipal());
byte[] b = mesg.getPreMasterSecret().getUnencrypted();
return new SecretKeySpec(b, "TlsPremasterSecret");
}
/*
* Diffie Hellman key exchange is used when the server presented
* D-H parameters in its certificate (signed using RSA or DSS/DSA),
* or else the server presented no certificate but sent D-H params
* in a ServerKeyExchange message. Use of D-H is specified by the
* cipher suite chosen.
*
* The message optionally contains the client's D-H public key (if
* it wasn't not sent in a client certificate). As always with D-H,
* if a client and a server have each other's D-H public keys and
* they use common algorithm parameters, they have a shared key
* that's derived via the D-H calculation. That key becomes the
* pre-master secret.
*/
private SecretKey clientKeyExchange(DHClientKeyExchange mesg)
throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
return dh.getAgreedSecret(mesg.getClientPublicKey());
}
private SecretKey clientKeyExchange(ECDHClientKeyExchange mesg)
throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
return ecdh.getAgreedSecret(mesg.getEncodedPoint());
}
/*
* Client wrote a message to verify the certificate it sent earlier.
*
* Note that this certificate isn't involved in key exchange. Client
* authentication messages are included in the checksums used to
* validate the handshake (e.g. Finished messages). Other than that,
* the _exact_ identity of the client is less fundamental to protocol
* security than its role in selecting keys via the pre-master secret.
*/
private void clientCertificateVerify(CertificateVerify mesg)
throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
try {
PublicKey publicKey =
session.getPeerCertificates()[0].getPublicKey();
boolean valid = mesg.verify(protocolVersion, handshakeHash,
publicKey, session.getMasterSecret());
if (valid == false) {
fatalSE(Alerts.alert_bad_certificate,
"certificate verify message signature error");
}
} catch (GeneralSecurityException e) {
fatalSE(Alerts.alert_bad_certificate,
"certificate verify format error", e);
}
// reset the flag for clientCertificateVerify message
needClientVerify = false;
}
/*
* Client writes "finished" at the end of its handshake, after cipher
* spec is changed. We verify it and then send ours.
*
* When we're resuming a session, we'll have already sent our own
* Finished message so just the verification is needed.
*/
private void clientFinished(Finished mesg) throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
/*
* Verify if client did send the certificate when client
* authentication was required, otherwise server should not proceed
*/
if (doClientAuth == SSLEngineImpl.clauth_required) {
// get X500Principal of the end-entity certificate for X509-based
// ciphersuites, or Kerberos principal for Kerberos ciphersuites
session.getPeerPrincipal();
}
/*
* Verify if client did send clientCertificateVerify message following
* the client Certificate, otherwise server should not proceed
*/
if (needClientVerify) {
fatalSE(Alerts.alert_handshake_failure,
"client did not send certificate verify message");
}
/*
* Verify the client's message with the "before" digest of messages,
* and forget about continuing to use that digest.
*/
boolean verified = mesg.verify(protocolVersion, handshakeHash,
Finished.CLIENT, session.getMasterSecret());
if (!verified) {
fatalSE(Alerts.alert_handshake_failure,
"client 'finished' message doesn't verify");
// NOTREACHED
}
/*
* save client verify data for secure renegotiation
*/
if (secureRenegotiation) {
clientVerifyData = mesg.getVerifyData();
}
/*
* OK, it verified. If we're doing the full handshake, add that
* "Finished" message to the hash of handshake messages, then send
* the change_cipher_spec and Finished message.
*/
if (!resumingSession) {
input.digestNow();
sendChangeCipherAndFinish(true);
}
/*
* Update the session cache only after the handshake completed, else
* we're open to an attack against a partially completed handshake.
*/
session.setLastAccessedTime(System.currentTimeMillis());
if (!resumingSession && session.isRejoinable()) {
((SSLSessionContextImpl)sslContext.engineGetServerSessionContext())
.put(session);
if (debug != null && Debug.isOn("session")) {
System.out.println(
"%% Cached server session: " + session);
}
} else if (!resumingSession &&
debug != null && Debug.isOn("session")) {
System.out.println(
"%% Didn't cache non-resumable server session: "
+ session);
}
}
/*
* Compute finished message with the "server" digest (and then forget
* about that digest, it can't be used again).
*/
private void sendChangeCipherAndFinish(boolean finishedTag)
throws IOException {
output.flush();
Finished mesg = new Finished(protocolVersion, handshakeHash,
Finished.SERVER, session.getMasterSecret());
/*
* Send the change_cipher_spec record; then our Finished handshake
* message will be the last handshake message. Flush, and now we
* are ready for application data!!
*/
sendChangeCipherSpec(mesg, finishedTag);
/*
* save server verify data for secure renegotiation
*/
if (secureRenegotiation) {
serverVerifyData = mesg.getVerifyData();
}
/*
* Update state machine so client MUST send 'finished' next
* The update should only take place if it is not in the fast
* handshake mode since the server has to wait for a finished
* message from the client.
*/
if (finishedTag) {
state = HandshakeMessage.ht_finished;
}
}
/*
* Returns a HelloRequest message to kickstart renegotiations
*/
HandshakeMessage getKickstartMessage() {
return new HelloRequest();
}
/*
* Fault detected during handshake.
*/
void handshakeAlert(byte description) throws SSLProtocolException {
String message = Alerts.alertDescription(description);
if (debug != null && Debug.isOn("handshake")) {
System.out.println("SSL -- handshake alert: "
+ message);
}
/*
* It's ok to get a no_certificate alert from a client of which
* we *requested* authentication information.
* However, if we *required* it, then this is not acceptable.
*
* Anyone calling getPeerCertificates() on the
* session will get an SSLPeerUnverifiedException.
*/
if ((description == Alerts.alert_no_certificate) &&
(doClientAuth == SSLEngineImpl.clauth_requested)) {
return;
}
throw new SSLProtocolException("handshake alert: " + message);
}
/*
* RSA key exchange is normally used. The client encrypts a "pre-master
* secret" with the server's public key, from the Certificate (or else
* ServerKeyExchange) message that was sent to it by the server. That's
* decrypted using the private key before we get here.
*/
private SecretKey clientKeyExchange(RSAClientKeyExchange mesg) throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
return mesg.preMaster;
}
/*
* Verify the certificate sent by the client. We'll only get one if we
* sent a CertificateRequest to request client authentication. If we
* are in TLS mode, the client may send a message with no certificates
* to indicate it does not have an appropriate chain. (In SSLv3 mode,
* it would send a no certificate alert).
*/
private void clientCertificate(CertificateMsg mesg) throws IOException {
if (debug != null && Debug.isOn("handshake")) {
mesg.print(System.out);
}
X509Certificate[] peerCerts = mesg.getCertificateChain();
if (peerCerts.length == 0) {
/*
* If the client authentication is only *REQUESTED* (e.g.
* not *REQUIRED*, this is an acceptable condition.)
*/
if (doClientAuth == SSLEngineImpl.clauth_requested) {
return;
} else {
fatalSE(Alerts.alert_bad_certificate,
"null cert chain");
}
}
// ask the trust manager to verify the chain
X509TrustManager tm = sslContext.getX509TrustManager();
try {
// find out the types of client authentication used
PublicKey key = peerCerts[0].getPublicKey();
String keyAlgorithm = key.getAlgorithm();
String authType;
if (keyAlgorithm.equals("RSA")) {
authType = "RSA";
} else if (keyAlgorithm.equals("DSA")) {
authType = "DSA";
} else if (keyAlgorithm.equals("EC")) {
authType = "EC";
} else {
// unknown public key type
authType = "UNKNOWN";
}
String identificator = getHostnameVerificationSE();
if (tm instanceof X509ExtendedTrustManager) {
((X509ExtendedTrustManager)tm).checkClientTrusted(
(peerCerts != null ?
peerCerts.clone() :
null),
authType,
getHostSE(),
identificator);
} else {
if (identificator != null) {
throw new RuntimeException(
"trust manager does not support peer identification");
}
tm.checkClientTrusted(
(peerCerts != null ?
peerCerts.clone() :
peerCerts),
authType);
}
} catch (CertificateException e) {
// This will throw an exception, so include the original error.
fatalSE(Alerts.alert_certificate_unknown, e);
}
// set the flag for clientCertificateVerify message
needClientVerify = true;
session.setPeerCertificates(peerCerts);
}
}