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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
*
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package sun.security.ssl;
import java.security.*;
import java.security.interfaces.ECPublicKey;
import java.security.spec.*;
import javax.crypto.SecretKey;
import javax.crypto.KeyAgreement;
import javax.crypto.spec.*;
/**
* Helper class for the ECDH key exchange. It generates the appropriate
* ephemeral keys as necessary and performs the actual shared secret derivation.
*
* @since 1.6
* @author Andreas Sterbenz
*/
final class ECDHCrypt {
// our private key
private PrivateKey privateKey;
// our public key
private ECPublicKey publicKey;
// Called by ServerHandshaker for static ECDH
ECDHCrypt(PrivateKey privateKey, PublicKey publicKey) {
this.privateKey = privateKey;
this.publicKey = (ECPublicKey)publicKey;
}
// Called by ServerHandshaker for ephemeral ECDH
ECDHCrypt(String curveName, SecureRandom random) {
try {
KeyPairGenerator kpg = JsseJce.getKeyPairGenerator("EC");
ECGenParameterSpec params = new ECGenParameterSpec(curveName);
kpg.initialize(params, random);
KeyPair kp = kpg.generateKeyPair();
privateKey = kp.getPrivate();
publicKey = (ECPublicKey)kp.getPublic();
} catch (GeneralSecurityException e) {
throw new RuntimeException("Could not generate DH keypair", e);
}
}
// Called by ClientHandshaker with params it received from the server
ECDHCrypt(ECParameterSpec params, SecureRandom random) {
try {
KeyPairGenerator kpg = JsseJce.getKeyPairGenerator("EC");
kpg.initialize(params, random);
KeyPair kp = kpg.generateKeyPair();
privateKey = kp.getPrivate();
publicKey = (ECPublicKey)kp.getPublic();
} catch (GeneralSecurityException e) {
throw new RuntimeException("Could not generate DH keypair", e);
}
}
/**
* Gets the public key of this end of the key exchange.
*/
PublicKey getPublicKey() {
return publicKey;
}
// called by ClientHandshaker with either the server's static or ephemeral public key
SecretKey getAgreedSecret(PublicKey peerPublicKey) {
try {
KeyAgreement ka = JsseJce.getKeyAgreement("ECDH");
ka.init(privateKey);
ka.doPhase(peerPublicKey, true);
return ka.generateSecret("TlsPremasterSecret");
} catch (GeneralSecurityException e) {
throw new RuntimeException("Could not generate secret", e);
}
}
// called by ServerHandshaker
SecretKey getAgreedSecret(byte[] encodedPoint) {
try {
ECParameterSpec params = publicKey.getParams();
ECPoint point = JsseJce.decodePoint(encodedPoint, params.getCurve());
KeyFactory kf = JsseJce.getKeyFactory("EC");
ECPublicKeySpec spec = new ECPublicKeySpec(point, params);
PublicKey peerPublicKey = kf.generatePublic(spec);
return getAgreedSecret(peerPublicKey);
} catch (GeneralSecurityException e) {
throw new RuntimeException("Could not generate secret", e);
} catch (java.io.IOException e) {
throw new RuntimeException("Could not generate secret", e);
}
}
}