/*

 * Copyright (c) 2015, 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.IOException;

import java.nio.ByteBuffer;

import java.util.Objects;

import javax.net.ssl.SSLException;

/*

 * RFC6961 defines the TLS extension,"status_request_v2" (type 0x5),

 * which allows the client to request that the server perform OCSP

 * on the client's behalf.

 *

 * The RFC defines an CertStatusReqItemV2 structure:

 *

 *      struct {

 *          CertificateStatusType status_type;

 *          uint16 request_length;

 *          select (status_type) {

 *              case ocsp: OCSPStatusRequest;

 *              case ocsp_multi: OCSPStatusRequest;

 *          } request;

 *      } CertificateStatusRequestItemV2;

 *

 *      enum { ocsp(1), ocsp_multi(2), (255) } CertificateStatusType;

 */

final class CertStatusReqItemV2 {

    private final StatusRequestType statReqType;

    private final StatusRequest request;

    /**

     * Construct a {@code CertStatusReqItemV2} object using a type value

     *      and empty ResponderId and Extension lists.

     *

     * @param reqType the type of request (e.g. ocsp).  A {@code null} value

     *      is not allowed.

     * @param statReq the {@code StatusRequest} object used to provide the

     *      encoding for this {@code CertStatusReqItemV2}.  A {@code null}

     *      value is not allowed.

     *

     * @throws IllegalArgumentException if the provided {@code StatusRequest}

     *      does not match the type.

     * @throws NullPointerException if either the reqType or statReq arguments

     *      are {@code null}.

     */

    CertStatusReqItemV2(StatusRequestType reqType, StatusRequest statReq) {

        statReqType = Objects.requireNonNull(reqType,

                "Unallowed null value for status_type");

        request = Objects.requireNonNull(statReq,

                "Unallowed null value for request");

        // There is currently only one known status type (OCSP)

        // We can add more clauses to cover other types in the future

        if (statReqType.equals(StatusRequestType.OCSP) ||

                statReqType.equals(StatusRequestType.OCSP_MULTI)) {

            if (!(statReq instanceof OCSPStatusRequest)) {

                throw new IllegalArgumentException("StatusRequest not " +

                        "of type OCSPStatusRequest");

            }

        }

    }

    /**

     * Construct a {@code CertStatusReqItemV2} object from encoded bytes

     *

     * @param requestBytes the encoded bytes for the {@code CertStatusReqItemV2}

     *

     * @throws IOException if any decoding errors take place

     * @throws IllegalArgumentException if the parsed reqType value is not a

     *      supported status request type.

     */

    CertStatusReqItemV2(byte[] reqItemBytes) throws IOException {

        ByteBuffer reqBuf = ByteBuffer.wrap(reqItemBytes);

        statReqType = StatusRequestType.get(reqBuf.get());

        int requestLength = Short.toUnsignedInt(reqBuf.getShort());

        if (requestLength == reqBuf.remaining()) {

            byte[] statReqBytes = new byte[requestLength];

            reqBuf.get(statReqBytes);

            if (statReqType == StatusRequestType.OCSP ||

                    statReqType == StatusRequestType.OCSP_MULTI) {

                request = new OCSPStatusRequest(statReqBytes);

            } else {

                request = new UnknownStatusRequest(statReqBytes);

            }

        } else {

            throw new SSLException("Incorrect request_length: " +

                    "Expected " + reqBuf.remaining() + ", got " +

                    requestLength);

        }

    }

    /**

     * Construct an {@code CertStatusReqItemV2} object from data read from

     * a {@code HandshakeInputStream}

     *

     * @param s the {@code HandshakeInputStream} providing the encoded data

     *

     * @throws IOException if any decoding errors happen during object

     *      construction.

     * @throws IllegalArgumentException if the parsed reqType value is not a

     *      supported status request type.

     */

    CertStatusReqItemV2(HandshakeInStream in) throws IOException {

        statReqType = StatusRequestType.get(in.getInt8());

        int requestLength = in.getInt16();

        if (statReqType == StatusRequestType.OCSP ||

                statReqType == StatusRequestType.OCSP_MULTI) {

            request = new OCSPStatusRequest(in);

        } else {

            request = new UnknownStatusRequest(in, requestLength);

        }

    }

    /**

     * Return the length of this {@code CertStatusReqItemV2} in its encoded form

     *

     * @return the encoded length of this {@code CertStatusReqItemV2}

     */

    int length() {

        // The length is the the status type (1 byte) + the request length

        // field (2 bytes) + the StatusRequest data length.

        return request.length() + 3;

    }

    /**

     * Send the encoded {@code CertStatusReqItemV2} through a

     *      {@code HandshakeOutputStream}

     *

     * @param s the {@code HandshakeOutputStream} used to send the encoded data

     *

     * @throws IOException if any errors occur during the encoding process

     */

    void send(HandshakeOutStream s) throws IOException {

        s.putInt8(statReqType.id);

        s.putInt16(request.length());

        request.send(s);

    }

    /**

     * Create a string representation of this {@code CertStatusReqItemV2}

     *

     * @return the string representation of this {@code CertStatusReqItemV2}

     */

    @Override

    public String toString() {

        StringBuilder sb = new StringBuilder();

        sb.append("CertStatusReqItemV2: ").append(statReqType).append(", ");

        sb.append(request.toString());

        return sb.toString();

    }

    /**

     * Return the type field for this {@code CertStatusReqItemV2}

     *

     * @return the {@code StatusRequestType} for this extension.

     */

    StatusRequestType getType() {

        return statReqType;

    }

    /**

     * Get the underlying {@code StatusRequest} for this

     *      {@code CertStatusReqItemV2}

     *

     * @return the {@code StatusRequest}

     */

    StatusRequest getRequest() {

        return request;

    }

}