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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
 *
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package sun.security.pkcs11;

import java.security.*;
import java.security.spec.AlgorithmParameterSpec;

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

import sun.security.internal.spec.TlsMasterSecretParameterSpec;

import static sun.security.pkcs11.TemplateManager.*;
import sun.security.pkcs11.wrapper.*;
import static sun.security.pkcs11.wrapper.PKCS11Constants.*;

/**
 * KeyGenerator for the SSL/TLS master secret.
 *
 * @author  Andreas Sterbenz
 * @since   1.6
 */
public final class P11TlsMasterSecretGenerator extends KeyGeneratorSpi {

    private final static String MSG = "TlsMasterSecretGenerator must be "
        + "initialized using a TlsMasterSecretParameterSpec";

    // token instance
    private final Token token;

    // algorithm name
    private final String algorithm;

    // mechanism id
    private long mechanism;

    @SuppressWarnings("deprecation")
    private TlsMasterSecretParameterSpec spec;
    private P11Key p11Key;

    int version;

    P11TlsMasterSecretGenerator(Token token, String algorithm, long mechanism)
            throws PKCS11Exception {
        super();
        this.token = token;
        this.algorithm = algorithm;
        this.mechanism = mechanism;
    }

    protected void engineInit(SecureRandom random) {
        throw new InvalidParameterException(MSG);
    }

    @SuppressWarnings("deprecation")
    protected void engineInit(AlgorithmParameterSpec params,
            SecureRandom random) throws InvalidAlgorithmParameterException {
        if (params instanceof TlsMasterSecretParameterSpec == false) {
            throw new InvalidAlgorithmParameterException(MSG);
        }
        this.spec = (TlsMasterSecretParameterSpec)params;
        SecretKey key = spec.getPremasterSecret();
        // algorithm should be either TlsRsaPremasterSecret or TlsPremasterSecret,
        // but we omit the check
        try {
            p11Key = P11SecretKeyFactory.convertKey(token, key, null);
        } catch (InvalidKeyException e) {
            throw new InvalidAlgorithmParameterException("init() failed", e);
        }
        version = (spec.getMajorVersion() << 8) | spec.getMinorVersion();
        if ((version < 0x0300) || (version > 0x0302)) {
            throw new InvalidAlgorithmParameterException
                ("Only SSL 3.0, TLS 1.0, and TLS 1.1 supported");
        }
        // We assume the token supports the required mechanism. If it does not,
        // generateKey() will fail and the failover should take care of us.
    }

    protected void engineInit(int keysize, SecureRandom random) {
        throw new InvalidParameterException(MSG);
    }

    protected SecretKey engineGenerateKey() {
        if (spec == null) {
            throw new IllegalStateException
                ("TlsMasterSecretGenerator must be initialized");
        }
        CK_VERSION ckVersion;
        if (p11Key.getAlgorithm().equals("TlsRsaPremasterSecret")) {
            mechanism = (version == 0x0300) ? CKM_SSL3_MASTER_KEY_DERIVE
                                             : CKM_TLS_MASTER_KEY_DERIVE;
            ckVersion = new CK_VERSION(0, 0);
        } else {
            // Note: we use DH for all non-RSA premaster secrets. That includes
            // Kerberos. That should not be a problem because master secret
            // calculation is always a straightforward application of the
            // TLS PRF (or the SSL equivalent).
            // The only thing special about RSA master secret calculation is
            // that it extracts the version numbers from the premaster secret.
            mechanism = (version == 0x0300) ? CKM_SSL3_MASTER_KEY_DERIVE_DH
                                             : CKM_TLS_MASTER_KEY_DERIVE_DH;
            ckVersion = null;
        }
        byte[] clientRandom = spec.getClientRandom();
        byte[] serverRandom = spec.getServerRandom();
        CK_SSL3_RANDOM_DATA random =
                new CK_SSL3_RANDOM_DATA(clientRandom, serverRandom);
        CK_SSL3_MASTER_KEY_DERIVE_PARAMS params =
                new CK_SSL3_MASTER_KEY_DERIVE_PARAMS(random, ckVersion);

        Session session = null;
        try {
            session = token.getObjSession();
            CK_ATTRIBUTE[] attributes = token.getAttributes(O_GENERATE,
                CKO_SECRET_KEY, CKK_GENERIC_SECRET, new CK_ATTRIBUTE[0]);
            long keyID = token.p11.C_DeriveKey(session.id(),
                new CK_MECHANISM(mechanism, params), p11Key.keyID, attributes);
            int major, minor;
            ckVersion = params.pVersion;
            if (ckVersion == null) {
                major = -1;
                minor = -1;
            } else {
                major = ckVersion.major;
                minor = ckVersion.minor;
            }
            SecretKey key = P11Key.masterSecretKey(session, keyID,
                "TlsMasterSecret", 48 << 3, attributes, major, minor);
            return key;
        } catch (Exception e) {
            throw new ProviderException("Could not generate key", e);
        } finally {
            token.releaseSession(session);
        }
    }

}