/*

 * Copyright (c) 2015, 2018, 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.IOException;

import java.nio.ByteBuffer;

import java.text.MessageFormat;

import java.util.List;

import java.util.ArrayList;

import java.util.Locale;

import javax.net.ssl.SSLHandshakeException;

import java.security.cert.X509Certificate;

import sun.security.provider.certpath.OCSPResponse;

import sun.security.ssl.SSLHandshake.HandshakeMessage;

import static sun.security.ssl.CertStatusExtension.*;

import static sun.security.ssl.CertificateMessage.*;

/**

 * Consumers and producers for the CertificateStatus handshake message.

 * This message takes one of two related but slightly different forms,

 * depending on the type of stapling selected by the server.  The message

 * data will be of the form(s):

 *

 *  [status_request, RFC 6066]

 *

 *  struct {

 *      CertificateStatusType status_type;

 *      select (status_type) {

 *          case ocsp: OCSPResponse;

 *      } response;

 *  } CertificateStatus;

 *

 *  opaque OCSPResponse<1..2^24-1>;

 *

 *  [status_request_v2, RFC 6961]

 *

 *  struct {

 *      CertificateStatusType status_type;

 *      select (status_type) {

 *        case ocsp: OCSPResponse;

 *        case ocsp_multi: OCSPResponseList;

 *      } response;

 *  } CertificateStatus;

 *

 *  opaque OCSPResponse<0..2^24-1>;

 *

 *  struct {

 *      OCSPResponse ocsp_response_list<1..2^24-1>;

 *  } OCSPResponseList;

 */

final class CertificateStatus {

    static final SSLConsumer handshakeConsumer =

            new CertificateStatusConsumer();

    static final HandshakeProducer handshakeProducer =

            new CertificateStatusProducer();

    static final HandshakeAbsence handshakeAbsence =

            new CertificateStatusAbsence();

    /**

     * The CertificateStatus handshake message.

     */

    static final class CertificateStatusMessage extends HandshakeMessage {

        final CertStatusRequestType statusType;

        int encodedResponsesLen = 0;

        int messageLength = -1;

        final List<byte[]> encodedResponses = new ArrayList<>();

        CertificateStatusMessage(HandshakeContext handshakeContext) {

            super(handshakeContext);

            ServerHandshakeContext shc =

                    (ServerHandshakeContext)handshakeContext;

            // Get the Certificates from the SSLContextImpl amd the Stapling

            // parameters

            StatusResponseManager.StaplingParameters stapleParams =

                    shc.stapleParams;

            if (stapleParams == null) {

                throw new IllegalArgumentException(

                        "Unexpected null stapling parameters");

            }

            X509Certificate[] certChain =

                (X509Certificate[])shc.handshakeSession.getLocalCertificates();

            if (certChain == null) {

                throw new IllegalArgumentException(

                        "Unexpected null certificate chain");

            }

            // Walk the certificate list and add the correct encoded responses

            // to the encoded responses list

            statusType = stapleParams.statReqType;

            if (statusType == CertStatusRequestType.OCSP) {

                // Just worry about the first cert in the chain

                byte[] resp = stapleParams.responseMap.get(certChain[0]);

                if (resp == null) {

                    // A not-found return status means we should include

                    // a zero-length response in CertificateStatus.

                    // This is highly unlikely to happen in practice.

                    resp = new byte[0];

                }

                encodedResponses.add(resp);

                encodedResponsesLen += resp.length + 3;

            } else if (statusType == CertStatusRequestType.OCSP_MULTI) {

                for (X509Certificate cert : certChain) {

                    byte[] resp = stapleParams.responseMap.get(cert);

                    if (resp == null) {

                        resp = new byte[0];

                    }

                    encodedResponses.add(resp);

                    encodedResponsesLen += resp.length + 3;

                }

            } else {

                throw new IllegalArgumentException(

                        "Unsupported StatusResponseType: " + statusType);

            }

            messageLength = messageLength();

        }

        CertificateStatusMessage(HandshakeContext handshakeContext,

                ByteBuffer m) throws IOException {

            super(handshakeContext);

            statusType = CertStatusRequestType.valueOf((byte)Record.getInt8(m));

            if (statusType == CertStatusRequestType.OCSP) {

                byte[] respDER = Record.getBytes24(m);

                // Convert the incoming bytes to a OCSPResponse strucutre

                if (respDER.length > 0) {

                    encodedResponses.add(respDER);

                    encodedResponsesLen = 3 + respDER.length;

                } else {

                    handshakeContext.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                            "Zero-length OCSP Response");

                }

            } else if (statusType == CertStatusRequestType.OCSP_MULTI) {

                int respListLen = Record.getInt24(m);

                encodedResponsesLen = respListLen;

                // Add each OCSP reponse into the array list in the order

                // we receive them off the wire.  A zero-length array is

                // allowed for ocsp_multi, and means that a response for

                // a given certificate is not available.

                while (respListLen > 0) {

                    byte[] respDER = Record.getBytes24(m);

                    encodedResponses.add(respDER);

                    respListLen -= (respDER.length + 3);

                }

                if (respListLen != 0) {

                    handshakeContext.conContext.fatal(Alert.INTERNAL_ERROR,

                            "Bad OCSP response list length");

                }

            } else {

                handshakeContext.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                        "Unsupported StatusResponseType: " + statusType);

            }

            messageLength = messageLength();

        }

        @Override

        public SSLHandshake handshakeType() {

            return SSLHandshake.CERTIFICATE_STATUS;

        }

        @Override

        public int messageLength() {

            int len = 1;

            if (messageLength == -1) {

                if (statusType == CertStatusRequestType.OCSP) {

                    len += encodedResponsesLen;

                } else if (statusType == CertStatusRequestType.OCSP_MULTI) {

                    len += 3 + encodedResponsesLen;

                }

                messageLength = len;

            }

            return messageLength;

        }

        @Override

        public void send(HandshakeOutStream s) throws IOException {

            s.putInt8(statusType.id);

            if (statusType == CertStatusRequestType.OCSP) {

                s.putBytes24(encodedResponses.get(0));

            } else if (statusType == CertStatusRequestType.OCSP_MULTI) {

                s.putInt24(encodedResponsesLen);

                for (byte[] respBytes : encodedResponses) {

                    if (respBytes != null) {

                        s.putBytes24(respBytes);

                    } else {

                        s.putBytes24(null);

                    }

                }

            } else {

                // It is highly unlikely that we will fall into this section

                // of the code.

                throw new SSLHandshakeException("Unsupported status_type: " +

                        statusType.id);

            }

        }

        @Override

        public String toString() {

            StringBuilder sb = new StringBuilder();

            // Stringify the encoded OCSP response list

            for (byte[] respDER : encodedResponses) {

                if (respDER.length > 0) {

                    try {

                        OCSPResponse oResp = new OCSPResponse(respDER);

                        sb.append(oResp.toString()).append("\n");

                    } catch (IOException ioe) {

                        sb.append("OCSP Response Exception: ").append(ioe)

                                .append("\n");

                    }

                } else {

                    sb.append("<Zero-length entry>\n");

                }

            }

            MessageFormat messageFormat = new MessageFormat(

                "\"CertificateStatus\": '{'\n" +

                "  \"type\"                : \"{0}\",\n" +

                "  \"responses \"          : [\n" + "{1}\n" + "  ]\n" +

                "'}'",

                Locale.ENGLISH);

            Object[] messageFields = {

                statusType.name,

                Utilities.indent(Utilities.indent(sb.toString()))

            };

            return messageFormat.format(messageFields);

        }

    }

    /**

     * The CertificateStatus handshake message consumer.

     */

    private static final class CertificateStatusConsumer

            implements SSLConsumer {

        // Prevent instantiation of this class.

        private CertificateStatusConsumer() {

            // blank

        }

        @Override

        public void consume(ConnectionContext context,

                ByteBuffer message) throws IOException {

            ClientHandshakeContext chc = (ClientHandshakeContext)context;

            CertificateStatusMessage cst =

                    new CertificateStatusMessage(chc, message);

            // Log the message

            if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {

                SSLLogger.fine(

                        "Consuming server CertificateStatus handshake message",

                        cst);

            }

            // Pin the received responses to the SSLSessionImpl.  It will

            // be retrieved by the X509TrustManagerImpl during the certficicate

            // checking phase.

            chc.handshakeSession.setStatusResponses(cst.encodedResponses);

            // Now perform the check

            T12CertificateConsumer.checkServerCerts(chc, chc.deferredCerts);

        }

    }

    /**

     * The CertificateStatus handshake message consumer.

     */

    private static final class CertificateStatusProducer

            implements HandshakeProducer {

        // Prevent instantiation of this class.

        private CertificateStatusProducer() {

            // blank

        }

        @Override

        public byte[] produce(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // Only the server-side should be a producer of this message

            ServerHandshakeContext shc = (ServerHandshakeContext)context;

            // If stapling is not active, immediately return without producing

            // a message or any further processing.

            if (!shc.staplingActive) {

                return null;

            }

            // Create the CertificateStatus message from info in the

            CertificateStatusMessage csm = new CertificateStatusMessage(shc);

            if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {

                SSLLogger.fine(

                    "Produced server CertificateStatus handshake message", csm);

            }

            // Output the handshake message.

            csm.write(shc.handshakeOutput);

            shc.handshakeOutput.flush();

            // The handshake message has been delivered.

            return null;

        }

    }

    private static final class CertificateStatusAbsence

            implements HandshakeAbsence {

        // Prevent instantiation of this class

        private CertificateStatusAbsence() {

            // blank

        }

        @Override

        public void absent(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            ClientHandshakeContext chc = (ClientHandshakeContext)context;

            // Processing should only continue if stapling is active

            if (chc.staplingActive) {

                // Because OCSP stapling is active, it means two things

                // if we're here: 1) The server hello asserted the

                // status_request[_v2] extension.  2) The CertificateStatus

                // message was not sent.  This means that cert path checking

                // was deferred, but must happen immediately.

                if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {

                    SSLLogger.fine("Server did not send CertificateStatus, " +

                            "checking cert chain without status info.");

                }

                T12CertificateConsumer.checkServerCerts(chc, chc.deferredCerts);

            }

        }

    }

}