/*

 * Copyright (c) 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.security.PrivateKey;

import java.security.PublicKey;

import java.security.cert.X509Certificate;

import java.security.interfaces.ECPublicKey;

import java.security.spec.ECParameterSpec;

import java.util.AbstractMap.SimpleImmutableEntry;

import java.util.Map;

import javax.net.ssl.SSLEngine;

import javax.net.ssl.SSLSocket;

import javax.net.ssl.X509ExtendedKeyManager;

import sun.security.ssl.SupportedGroupsExtension.NamedGroup;

import sun.security.ssl.SupportedGroupsExtension.SupportedGroups;

enum X509Authentication implements SSLAuthentication {

    RSA     ("RSA",        new X509PossessionGenerator("RSA")),

    RSA_PSS ("RSASSA-PSS", new X509PossessionGenerator("RSASSA-PSS")),

    DSA     ("DSA",        new X509PossessionGenerator("DSA")),

    EC      ("EC",         new X509PossessionGenerator("EC"));

    final String keyType;

    final SSLPossessionGenerator possessionGenerator;

    X509Authentication(String keyType,

            SSLPossessionGenerator possessionGenerator) {

        this.keyType = keyType;

        this.possessionGenerator = possessionGenerator;

    }

    static X509Authentication nameOf(String keyType) {

        for (X509Authentication au: X509Authentication.values()) {

            if (au.keyType.equals(keyType)) {

                return au;

            }

        }

        return null;

    }

    @Override

    public SSLPossession createPossession(HandshakeContext handshakeContext) {

        return possessionGenerator.createPossession(handshakeContext);

    }

    @Override

    public SSLHandshake[] getRelatedHandshakers(

            HandshakeContext handshakeContext) {

        if (!handshakeContext.negotiatedProtocol.useTLS13PlusSpec()) {

            return new SSLHandshake[] {

                    SSLHandshake.CERTIFICATE,

                    SSLHandshake.CERTIFICATE_REQUEST

                };

        }   // Otherwise, TLS 1.3 does not use this method.

        return new SSLHandshake[0];

    }

    @SuppressWarnings({"unchecked", "rawtypes"})

    @Override

    public Map.Entry<Byte, HandshakeProducer>[] getHandshakeProducers(

            HandshakeContext handshakeContext) {

        if (!handshakeContext.negotiatedProtocol.useTLS13PlusSpec()) {

            return (Map.Entry<Byte, HandshakeProducer>[])(new Map.Entry[] {

                    new SimpleImmutableEntry<Byte, HandshakeProducer>(

                        SSLHandshake.CERTIFICATE.id,

                        SSLHandshake.CERTIFICATE

                    )

                });

        }   // Otherwise, TLS 1.3 does not use this method.

        return (Map.Entry<Byte, HandshakeProducer>[])(new Map.Entry[0]);

    }

    static final class X509Possession implements SSLPossession {

        // Proof of possession of the private key corresponding to the public

        // key for which a certificate is being provided for authentication.

        final X509Certificate[]   popCerts;

        final PrivateKey          popPrivateKey;

        X509Possession(PrivateKey popPrivateKey,

                X509Certificate[] popCerts) {

            this.popCerts = popCerts;

            this.popPrivateKey = popPrivateKey;

        }

    }

    static final class X509Credentials implements SSLCredentials {

        final X509Certificate[]   popCerts;

        final PublicKey           popPublicKey;

        X509Credentials(PublicKey popPublicKey, X509Certificate[] popCerts) {

            this.popCerts = popCerts;

            this.popPublicKey = popPublicKey;

        }

    }

    private static final

            class X509PossessionGenerator implements SSLPossessionGenerator {

        final String keyType;

        private X509PossessionGenerator(String keyType) {

            this.keyType = keyType;

        }

        @Override

        public SSLPossession createPossession(HandshakeContext context) {

            if (context.sslConfig.isClientMode) {

                return createClientPossession((ClientHandshakeContext)context);

            } else {

                return createServerPossession((ServerHandshakeContext)context);

            }

        }

        // Used by TLS 1.3 only.

        private SSLPossession createClientPossession(

                ClientHandshakeContext chc) {

            X509ExtendedKeyManager km = chc.sslContext.getX509KeyManager();

            String clientAlias = null;

            if (chc.conContext.transport instanceof SSLSocketImpl) {

                clientAlias = km.chooseClientAlias(

                        new String[] { keyType },

                        null, (SSLSocket)chc.conContext.transport);

            } else if (chc.conContext.transport instanceof SSLEngineImpl) {

                clientAlias = km.chooseEngineClientAlias(

                        new String[] { keyType },

                        null, (SSLEngine)chc.conContext.transport);

            }

            if (clientAlias == null) {

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

                    SSLLogger.finest("No X.509 cert selected for " + keyType);

                }

                return null;

            }

            PrivateKey clientPrivateKey = km.getPrivateKey(clientAlias);

            if (clientPrivateKey == null) {

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

                    SSLLogger.finest(

                            clientAlias + " is not a private key entry");

                }

                return null;

            }

            X509Certificate[] clientCerts = km.getCertificateChain(clientAlias);

            if ((clientCerts == null) || (clientCerts.length == 0)) {

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

                    SSLLogger.finest(

                            clientAlias + " is not a certificate entry");

                }

                return null;

            }

            PublicKey clientPublicKey = clientCerts[0].getPublicKey();

            if ((!clientPrivateKey.getAlgorithm().equals(keyType))

                    || (!clientPublicKey.getAlgorithm().equals(keyType))) {

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

                    SSLLogger.fine(

                            clientAlias + " private or public key is not of " +

                            keyType + " algorithm");

                }

                return null;

            }

            return new X509Possession(clientPrivateKey, clientCerts);

        }

        private SSLPossession createServerPossession(

                ServerHandshakeContext shc) {

            X509ExtendedKeyManager km = shc.sslContext.getX509KeyManager();

            String serverAlias = null;

            if (shc.conContext.transport instanceof SSLSocketImpl) {

                serverAlias = km.chooseServerAlias(keyType,

                        null, (SSLSocket)shc.conContext.transport);

            } else if (shc.conContext.transport instanceof SSLEngineImpl) {

                serverAlias = km.chooseEngineServerAlias(keyType,

                        null, (SSLEngine)shc.conContext.transport);

            }

            if (serverAlias == null) {

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

                    SSLLogger.finest("No X.509 cert selected for " + keyType);

                }

                return null;

            }

            PrivateKey serverPrivateKey = km.getPrivateKey(serverAlias);

            if (serverPrivateKey == null) {

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

                    SSLLogger.finest(

                            serverAlias + " is not a private key entry");

                }

                return null;

            }

            X509Certificate[] serverCerts = km.getCertificateChain(serverAlias);

            if ((serverCerts == null) || (serverCerts.length == 0)) {

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

                    SSLLogger.finest(

                            serverAlias + " is not a certificate entry");

                }

                return null;

            }

            PublicKey serverPublicKey = serverCerts[0].getPublicKey();

            if ((!serverPrivateKey.getAlgorithm().equals(keyType))

                    || (!serverPublicKey.getAlgorithm().equals(keyType))) {

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

                    SSLLogger.fine(

                            serverAlias + " private or public key is not of " +

                            keyType + " algorithm");

                }

                return null;

            }

            // For ECC certs, check whether we support the EC domain

            // parameters.  If the client sent a SupportedEllipticCurves

            // ClientHello extension, check against that too.

            if (keyType.equals("EC")) {

                if (!(serverPublicKey instanceof ECPublicKey)) {

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

                        SSLLogger.warning(serverAlias +

                            " public key is not an instance of ECPublicKey");

                    }

                    return null;

                }

                // For ECC certs, check whether we support the EC domain

                // parameters. If the client sent a SupportedEllipticCurves

                // ClientHello extension, check against that too.

                ECParameterSpec params =

                        ((ECPublicKey)serverPublicKey).getParams();

                NamedGroup namedGroup = NamedGroup.valueOf(params);

                if ((namedGroup == null) ||

                    (!SupportedGroups.isSupported(namedGroup)) ||

                    ((shc.clientRequestedNamedGroups != null) &&

                    !shc.clientRequestedNamedGroups.contains(namedGroup))) {

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

                        SSLLogger.warning(

                            "Unsupported named group (" + namedGroup +

                            ") used in the " + serverAlias + " certificate");

                    }

                    return null;

                }

            }

            return new X509Possession(serverPrivateKey, serverCerts);

        }

    }

}