ojluni/src/main/java/sun/security/ssl/RSAClientKeyExchange.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 1996, 2012, 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;

 import java.io.*;
 import java.security.*;
 import java.security.interfaces.*;

 import javax.crypto.*;
 import javax.crypto.spec.*;

 import javax.net.ssl.*;

 import sun.security.internal.spec.TlsRsaPremasterSecretParameterSpec;
 import sun.security.util.KeyUtil;

 /**
  * This is the client key exchange message (CLIENT --> SERVER) used with
  * all RSA key exchanges; it holds the RSA-encrypted pre-master secret.
  *
  * The message is encrypted using PKCS #1 block type 02 encryption with the
  * server's public key.  The padding and resulting message size is a function
  * of this server's public key modulus size, but the pre-master secret is
  * always exactly 48 bytes.
  *
  */
 final class RSAClientKeyExchange extends HandshakeMessage {

     /**
      * The TLS spec says that the version in the RSA premaster secret must
      * be the maximum version supported by the client (i.e. the version it
      * requested in its client hello version). However, we (and other
      * implementations) used to send the active negotiated version. The
      * system property below allows to toggle the behavior.
      */
     private final static String PROP_NAME =
                                 "com.sun.net.ssl.rsaPreMasterSecretFix";

     /*
      * Default is "false" (old behavior) for compatibility reasons in
      * SSLv3/TLSv1.  Later protocols (TLSv1.1+) do not use this property.
      */
     private final static boolean rsaPreMasterSecretFix =
                                 Debug.getBooleanProperty(PROP_NAME, false);

     /*
      * The following field values were encrypted with the server's public
      * key (or temp key from server key exchange msg) and are presented
      * here in DECRYPTED form.
      */
     private ProtocolVersion protocolVersion; // preMaster [0,1]
     SecretKey preMaster;
     private byte[] encrypted;           // same size as public modulus

     /*
      * Client randomly creates a pre-master secret and encrypts it
      * using the server's RSA public key; only the server can decrypt
      * it, using its RSA private key.  Result is the same size as the
      * server's public key, and uses PKCS #1 block format 02.
      */
     RSAClientKeyExchange(ProtocolVersion protocolVersion,
             ProtocolVersion maxVersion,
             SecureRandom generator, PublicKey publicKey) throws IOException {
         if (publicKey.getAlgorithm().equals("RSA") == false) {
             throw new SSLKeyException("Public key not of type RSA");
         }
         this.protocolVersion = protocolVersion;

         int major, minor;

         if (rsaPreMasterSecretFix || maxVersion.v >= ProtocolVersion.TLS11.v) {
             major = maxVersion.major;
             minor = maxVersion.minor;
         } else {
             major = protocolVersion.major;
             minor = protocolVersion.minor;
         }

         try {
             String s = ((protocolVersion.v >= ProtocolVersion.TLS12.v) ?
                 "SunTls12RsaPremasterSecret" : "SunTlsRsaPremasterSecret");
             KeyGenerator kg = JsseJce.getKeyGenerator(s);
             kg.init(new TlsRsaPremasterSecretParameterSpec(major, minor),
                     generator);
             preMaster = kg.generateKey();

             Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
             cipher.init(Cipher.WRAP_MODE, publicKey, generator);
             encrypted = cipher.wrap(preMaster);
         } catch (GeneralSecurityException e) {
             throw (SSLKeyException)new SSLKeyException
                                 ("RSA premaster secret error").initCause(e);
         }
     }

     /*
      * Server gets the PKCS #1 (block format 02) data, decrypts
      * it with its private key.
      */
     RSAClientKeyExchange(ProtocolVersion currentVersion,
             ProtocolVersion maxVersion,
             SecureRandom generator, HandshakeInStream input,
             int messageSize, PrivateKey privateKey) throws IOException {

         if (privateKey.getAlgorithm().equals("RSA") == false) {
             throw new SSLKeyException("Private key not of type RSA");
         }

         if (currentVersion.v >= ProtocolVersion.TLS10.v) {
             encrypted = input.getBytes16();
         } else {
             encrypted = new byte [messageSize];
             if (input.read(encrypted) != messageSize) {
                 throw new SSLProtocolException
                         ("SSL: read PreMasterSecret: short read");
             }
         }

         try {
             Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
             cipher.init(Cipher.UNWRAP_MODE, privateKey);
             preMaster = (SecretKey)cipher.unwrap(encrypted,
                                 "TlsRsaPremasterSecret", Cipher.SECRET_KEY);

             // polish the premaster secret
             preMaster = polishPreMasterSecretKey(currentVersion, maxVersion,
                                                 generator, preMaster, null);
         } catch (Exception e) {
             // polish the premaster secret
             preMaster =
                     polishPreMasterSecretKey(currentVersion, maxVersion,
                                                 generator, null, e);
         }
     }

     /**
      * To avoid vulnerabilities described by section 7.4.7.1, RFC 5246,
      * treating incorrectly formatted message blocks and/or mismatched
      * version numbers in a manner indistinguishable from correctly
      * formatted RSA blocks.
      *
      * RFC 5246 describes the approach as :
      *
      *  1. Generate a string R of 46 random bytes
      *
      *  2. Decrypt the message to recover the plaintext M
      *
      *  3. If the PKCS#1 padding is not correct, or the length of message
      *     M is not exactly 48 bytes:
      *        pre_master_secret = ClientHello.client_version || R
      *     else If ClientHello.client_version <= TLS 1.0, and version
      *     number check is explicitly disabled:
      *        pre_master_secret = M
      *     else:
      *        pre_master_secret = ClientHello.client_version || M[2..47]
      */
     private SecretKey polishPreMasterSecretKey(ProtocolVersion currentVersion,
             ProtocolVersion clientHelloVersion, SecureRandom generator,
             SecretKey secretKey, Exception failoverException) {

         this.protocolVersion = clientHelloVersion;

         if (failoverException == null && secretKey != null) {
             // check the length
             byte[] encoded = secretKey.getEncoded();
             if (encoded == null) {      // unable to get the encoded key
                 if (debug != null && Debug.isOn("handshake")) {
                     System.out.println(
                         "unable to get the plaintext of the premaster secret");
                 }

                 int keySize = KeyUtil.getKeySize(secretKey);
                 if (keySize > 0 && keySize != 384) {       // 384 = 48 * 8
                     if (debug != null && Debug.isOn("handshake")) {
                         System.out.println(
                             "incorrect length of premaster secret: " +
                             (keySize/8));
                     }

                     return generateDummySecret(clientHelloVersion);
                 }

                 // The key size is exactly 48 bytes or not accessible.
                 //
                 // Conservatively, pass the checking to master secret
                 // calculation.
                 return secretKey;
             } else if (encoded.length == 48) {
                 // check the version
                 if (clientHelloVersion.major == encoded[0] &&
                     clientHelloVersion.minor == encoded[1]) {

                     return secretKey;
                 } else if (clientHelloVersion.v <= ProtocolVersion.TLS10.v &&
                            currentVersion.major == encoded[0] &&
                            currentVersion.minor == encoded[1]) {
                     /*
                      * For compatibility, we maintain the behavior that the
                      * version in pre_master_secret can be the negotiated
                      * version for TLS v1.0 and SSL v3.0.
                      */
                     this.protocolVersion = currentVersion;
                     return secretKey;
                 }

                 if (debug != null && Debug.isOn("handshake")) {
                     System.out.println("Mismatching Protocol Versions, " +
                         "ClientHello.client_version is " + clientHelloVersion +
                         ", while PreMasterSecret.client_version is " +
                         ProtocolVersion.valueOf(encoded[0], encoded[1]));
                 }

                 return generateDummySecret(clientHelloVersion);
             } else {
                 if (debug != null && Debug.isOn("handshake")) {
                     System.out.println(
                         "incorrect length of premaster secret: " +
                         encoded.length);
                 }

                 return generateDummySecret(clientHelloVersion);
             }
         }

         if (debug != null && Debug.isOn("handshake") &&
                     failoverException != null) {
             System.out.println("Error decrypting premaster secret:");
             failoverException.printStackTrace(System.out);
         }

         return generateDummySecret(clientHelloVersion);
     }

     // generate a premaster secret with the specified version number
     static SecretKey generateDummySecret(ProtocolVersion version) {
         if (debug != null && Debug.isOn("handshake")) {
             System.out.println("Generating a random fake premaster secret");
         }

         try {
             String s = ((version.v >= ProtocolVersion.TLS12.v) ?
                 "SunTls12RsaPremasterSecret" : "SunTlsRsaPremasterSecret");
             KeyGenerator kg = JsseJce.getKeyGenerator(s);
             kg.init(new TlsRsaPremasterSecretParameterSpec
                     (version.major, version.minor));
             return kg.generateKey();
         } catch (GeneralSecurityException e) {
             throw new RuntimeException("Could not generate dummy secret", e);
         }
     }

     @Override
     int messageType() {
         return ht_client_key_exchange;
     }

     @Override
     int messageLength() {
         if (protocolVersion.v >= ProtocolVersion.TLS10.v) {
             return encrypted.length + 2;
         } else {
             return encrypted.length;
         }
     }

     @Override
     void send(HandshakeOutStream s) throws IOException {
         if (protocolVersion.v >= ProtocolVersion.TLS10.v) {
             s.putBytes16(encrypted);
         } else {
             s.write(encrypted);
         }
     }

     @Override
     void print(PrintStream s) throws IOException {
         s.println("*** ClientKeyExchange, RSA PreMasterSecret, " +
                                                         protocolVersion);
     }
 }
	/*
	* Copyright (c) 1996, 2012, 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;

	import java.io.*;
	import java.security.*;
	import java.security.interfaces.*;

	import javax.crypto.*;
	import javax.crypto.spec.*;

	import javax.net.ssl.*;

	import sun.security.internal.spec.TlsRsaPremasterSecretParameterSpec;
	import sun.security.util.KeyUtil;

	/**
	* This is the client key exchange message (CLIENT --> SERVER) used with
	* all RSA key exchanges; it holds the RSA-encrypted pre-master secret.
	*
	* The message is encrypted using PKCS #1 block type 02 encryption with the
	* server's public key. The padding and resulting message size is a function
	* of this server's public key modulus size, but the pre-master secret is
	* always exactly 48 bytes.
	*
	*/
	final class RSAClientKeyExchange extends HandshakeMessage {

	/**
	* The TLS spec says that the version in the RSA premaster secret must
	* be the maximum version supported by the client (i.e. the version it
	* requested in its client hello version). However, we (and other
	* implementations) used to send the active negotiated version. The
	* system property below allows to toggle the behavior.
	*/
	private final static String PROP_NAME =
	"com.sun.net.ssl.rsaPreMasterSecretFix";

	/*
	* Default is "false" (old behavior) for compatibility reasons in
	* SSLv3/TLSv1. Later protocols (TLSv1.1+) do not use this property.
	*/
	private final static boolean rsaPreMasterSecretFix =
	Debug.getBooleanProperty(PROP_NAME, false);

	/*
	* The following field values were encrypted with the server's public
	* key (or temp key from server key exchange msg) and are presented
	* here in DECRYPTED form.
	*/
	private ProtocolVersion protocolVersion; // preMaster [0,1]
	SecretKey preMaster;
	private byte[] encrypted; // same size as public modulus

	/*
	* Client randomly creates a pre-master secret and encrypts it
	* using the server's RSA public key; only the server can decrypt
	* it, using its RSA private key. Result is the same size as the
	* server's public key, and uses PKCS #1 block format 02.
	*/
	RSAClientKeyExchange(ProtocolVersion protocolVersion,
	ProtocolVersion maxVersion,
	SecureRandom generator, PublicKey publicKey) throws IOException {
	if (publicKey.getAlgorithm().equals("RSA") == false) {
	throw new SSLKeyException("Public key not of type RSA");
	}
	this.protocolVersion = protocolVersion;

	int major, minor;

	if (rsaPreMasterSecretFix \|\| maxVersion.v >= ProtocolVersion.TLS11.v) {
	major = maxVersion.major;
	minor = maxVersion.minor;
	} else {
	major = protocolVersion.major;
	minor = protocolVersion.minor;
	}

	try {
	String s = ((protocolVersion.v >= ProtocolVersion.TLS12.v) ?
	"SunTls12RsaPremasterSecret" : "SunTlsRsaPremasterSecret");
	KeyGenerator kg = JsseJce.getKeyGenerator(s);
	kg.init(new TlsRsaPremasterSecretParameterSpec(major, minor),
	generator);
	preMaster = kg.generateKey();

	Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
	cipher.init(Cipher.WRAP_MODE, publicKey, generator);
	encrypted = cipher.wrap(preMaster);
	} catch (GeneralSecurityException e) {
	throw (SSLKeyException)new SSLKeyException
	("RSA premaster secret error").initCause(e);
	}
	}

	/*
	* Server gets the PKCS #1 (block format 02) data, decrypts
	* it with its private key.
	*/
	RSAClientKeyExchange(ProtocolVersion currentVersion,
	ProtocolVersion maxVersion,
	SecureRandom generator, HandshakeInStream input,
	int messageSize, PrivateKey privateKey) throws IOException {

	if (privateKey.getAlgorithm().equals("RSA") == false) {
	throw new SSLKeyException("Private key not of type RSA");
	}

	if (currentVersion.v >= ProtocolVersion.TLS10.v) {
	encrypted = input.getBytes16();
	} else {
	encrypted = new byte [messageSize];
	if (input.read(encrypted) != messageSize) {
	throw new SSLProtocolException
	("SSL: read PreMasterSecret: short read");
	}
	}

	try {
	Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
	cipher.init(Cipher.UNWRAP_MODE, privateKey);
	preMaster = (SecretKey)cipher.unwrap(encrypted,
	"TlsRsaPremasterSecret", Cipher.SECRET_KEY);

	// polish the premaster secret
	preMaster = polishPreMasterSecretKey(currentVersion, maxVersion,
	generator, preMaster, null);
	} catch (Exception e) {
	// polish the premaster secret
	preMaster =
	polishPreMasterSecretKey(currentVersion, maxVersion,
	generator, null, e);
	}
	}

	/**
	* To avoid vulnerabilities described by section 7.4.7.1, RFC 5246,
	* treating incorrectly formatted message blocks and/or mismatched
	* version numbers in a manner indistinguishable from correctly
	* formatted RSA blocks.
	*
	* RFC 5246 describes the approach as :
	*
	* 1. Generate a string R of 46 random bytes
	*
	* 2. Decrypt the message to recover the plaintext M
	*
	* 3. If the PKCS#1 padding is not correct, or the length of message
	* M is not exactly 48 bytes:
	* pre_master_secret = ClientHello.client_version \|\| R
	* else If ClientHello.client_version <= TLS 1.0, and version
	* number check is explicitly disabled:
	* pre_master_secret = M
	* else:
	* pre_master_secret = ClientHello.client_version \|\| M[2..47]
	*/
	private SecretKey polishPreMasterSecretKey(ProtocolVersion currentVersion,
	ProtocolVersion clientHelloVersion, SecureRandom generator,
	SecretKey secretKey, Exception failoverException) {

	this.protocolVersion = clientHelloVersion;

	if (failoverException == null && secretKey != null) {
	// check the length
	byte[] encoded = secretKey.getEncoded();
	if (encoded == null) { // unable to get the encoded key
	if (debug != null && Debug.isOn("handshake")) {
	System.out.println(
	"unable to get the plaintext of the premaster secret");
	}

	int keySize = KeyUtil.getKeySize(secretKey);
	if (keySize > 0 && keySize != 384) { // 384 = 48 * 8
	if (debug != null && Debug.isOn("handshake")) {
	System.out.println(
	"incorrect length of premaster secret: " +
	(keySize/8));
	}

	return generateDummySecret(clientHelloVersion);
	}

	// The key size is exactly 48 bytes or not accessible.
	//
	// Conservatively, pass the checking to master secret
	// calculation.
	return secretKey;
	} else if (encoded.length == 48) {
	// check the version
	if (clientHelloVersion.major == encoded[0] &&
	clientHelloVersion.minor == encoded[1]) {

	return secretKey;
	} else if (clientHelloVersion.v <= ProtocolVersion.TLS10.v &&
	currentVersion.major == encoded[0] &&
	currentVersion.minor == encoded[1]) {
	/*
	* For compatibility, we maintain the behavior that the
	* version in pre_master_secret can be the negotiated
	* version for TLS v1.0 and SSL v3.0.
	*/
	this.protocolVersion = currentVersion;
	return secretKey;
	}

	if (debug != null && Debug.isOn("handshake")) {
	System.out.println("Mismatching Protocol Versions, " +
	"ClientHello.client_version is " + clientHelloVersion +
	", while PreMasterSecret.client_version is " +
	ProtocolVersion.valueOf(encoded[0], encoded[1]));
	}

	return generateDummySecret(clientHelloVersion);
	} else {
	if (debug != null && Debug.isOn("handshake")) {
	System.out.println(
	"incorrect length of premaster secret: " +
	encoded.length);
	}

	return generateDummySecret(clientHelloVersion);
	}
	}

	if (debug != null && Debug.isOn("handshake") &&
	failoverException != null) {
	System.out.println("Error decrypting premaster secret:");
	failoverException.printStackTrace(System.out);
	}

	return generateDummySecret(clientHelloVersion);
	}

	// generate a premaster secret with the specified version number
	static SecretKey generateDummySecret(ProtocolVersion version) {
	if (debug != null && Debug.isOn("handshake")) {
	System.out.println("Generating a random fake premaster secret");
	}

	try {
	String s = ((version.v >= ProtocolVersion.TLS12.v) ?
	"SunTls12RsaPremasterSecret" : "SunTlsRsaPremasterSecret");
	KeyGenerator kg = JsseJce.getKeyGenerator(s);
	kg.init(new TlsRsaPremasterSecretParameterSpec
	(version.major, version.minor));
	return kg.generateKey();
	} catch (GeneralSecurityException e) {
	throw new RuntimeException("Could not generate dummy secret", e);
	}
	}

	@Override
	int messageType() {
	return ht_client_key_exchange;
	}

	@Override
	int messageLength() {
	if (protocolVersion.v >= ProtocolVersion.TLS10.v) {
	return encrypted.length + 2;
	} else {
	return encrypted.length;
	}
	}

	@Override
	void send(HandshakeOutStream s) throws IOException {
	if (protocolVersion.v >= ProtocolVersion.TLS10.v) {
	s.putBytes16(encrypted);
	} else {
	s.write(encrypted);
	}
	}

	@Override
	void print(PrintStream s) throws IOException {
	s.println("*** ClientKeyExchange, RSA PreMasterSecret, " +
	protocolVersion);
	}
	}