# ServerConnFactoryBuilder.java

    /*
     *  Licensed to the Apache Software Foundation (ASF) under one
     *  or more contributor license agreements.  See the NOTICE file
     *  distributed with this work for additional information
     *  regarding copyright ownership.  The ASF licenses this file
     *  to you under the Apache License, Version 2.0 (the
     *  "License"); you may not use this file except in compliance
     *  with the License.  You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     *  Unless required by applicable law or agreed to in writing,
     *  software distributed under the License is distributed on an
     *   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     *  KIND, either express or implied.  See the License for the
     *  specific language governing permissions and limitations
     *  under the License.
     */

    package org.apache.synapse.transport.nhttp.config;

    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.om.impl.builder.StAXOMBuilder;
    import org.apache.axis2.AxisFault;
    import org.apache.axis2.context.ConfigurationContext;
    import org.apache.axis2.description.Parameter;
    import org.apache.axis2.description.TransportInDescription;
    import org.apache.axis2.transport.base.ParamUtils;
    import org.apache.commons.lang3.StringUtils;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.http.HttpHost;
    import org.apache.http.params.HttpParams;
    import org.apache.synapse.transport.certificatevalidation.CertificateVerificationManager;
    import org.apache.synapse.transport.http.conn.SSLClientAuth;
    import org.apache.synapse.transport.http.conn.SSLContextDetails;
    import org.apache.synapse.transport.http.conn.ServerConnFactory;
    import org.apache.synapse.transport.http.conn.ServerSSLSetupHandler;
    import org.apache.synapse.transport.nhttp.NhttpConstants;
    import org.apache.synapse.transport.nhttp.util.SecureVaultValueReader;
    import org.wso2.securevault.SecretResolver;
    import org.wso2.securevault.SecretResolverFactory;

    import javax.net.ssl.KeyManager;
    import javax.net.ssl.KeyManagerFactory;
    import javax.net.ssl.SSLContext;
    import javax.net.ssl.TrustManager;
    import javax.net.ssl.TrustManagerFactory;
    import javax.net.ssl.X509KeyManager;
    import javax.xml.namespace.QName;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.security.GeneralSecurityException;
    import java.security.KeyStore;
    import java.security.cert.X509Certificate;
    import java.util.ArrayList;
    import java.util.Enumeration;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.List;
    import java.util.Locale;
    import java.util.Map;

    public class ServerConnFactoryBuilder {

        private final Log log = LogFactory.getLog(ServerConnFactoryBuilder.class);

        private final TransportInDescription transportIn;
        private final HttpHost host;
        private final String name;

        protected SSLContextDetails ssl;
        private Map<InetSocketAddress, SSLContextDetails> sslByIPMap = null;
        private ConfigurationContext configurationContext;
        CertificateVerificationManager certificateVerifier = null;

        public ServerConnFactoryBuilder(final TransportInDescription transportIn, final HttpHost host,
                                        ConfigurationContext configurationContext) {
            this.transportIn = transportIn;
            this.host = host;
            this.name = transportIn.getName().toUpperCase(Locale.US);
            this.configurationContext = configurationContext;
        }

        public ServerConnFactoryBuilder(final TransportInDescription transportIn, final HttpHost host) {
            this.transportIn = transportIn;
            this.host = host;
            this.name = transportIn.getName().toUpperCase(Locale.US);
        }

        protected SSLContextDetails createSSLContext(
                final OMElement keyStoreEl,
                final OMElement trustStoreEl,
                final OMElement cientAuthEl,
                final OMElement httpsProtocolsEl,
                final OMElement preferredCiphersEl,
                final CertificateVerificationManager verificationManager,
                final String sslProtocol) throws AxisFault {

            SecretResolver secretResolver;
            if (configurationContext != null && configurationContext.getAxisConfiguration() != null) {
                secretResolver = configurationContext.getAxisConfiguration().getSecretResolver();
            } else {
                secretResolver = SecretResolverFactory.create(keyStoreEl, false);
            }

            return createSSLContext(keyStoreEl, trustStoreEl, cientAuthEl, httpsProtocolsEl, preferredCiphersEl,
                    verificationManager, sslProtocol, secretResolver);
        }

        protected SSLContextDetails createSSLContext(
                final OMElement keyStoreEl,
                final OMElement trustStoreEl,
                final OMElement cientAuthEl,
                final OMElement httpsProtocolsEl,
                final OMElement preferredCiphersEl,
                final CertificateVerificationManager verificationManager,
                final String sslProtocol, final SecretResolver secretResolver) throws AxisFault {

            KeyManager[] keymanagers  = null;
            TrustManager[] trustManagers = null;

            if (keyStoreEl != null) {
                String location      = getValueOfElementWithLocalName(keyStoreEl,"Location");
                String type          = getValueOfElementWithLocalName(keyStoreEl,"Type");
                OMElement storePasswordEl = keyStoreEl.getFirstChildWithName(new QName("Password"));
                OMElement keyPasswordEl = keyStoreEl.getFirstChildWithName(new QName("KeyPassword"));
                if (storePasswordEl == null) {
                    throw new AxisFault("Cannot proceed because Password element is missing in KeyStore");
                }
                if (keyPasswordEl == null) {
                    throw new AxisFault("Cannot proceed because KeyPassword element is missing in KeyStore");
                }
                String storePassword = SecureVaultValueReader.getSecureVaultValue(secretResolver, storePasswordEl);
                String keyPassword   = SecureVaultValueReader.getSecureVaultValue(secretResolver, keyPasswordEl);

                FileInputStream fis = null;
                try {
                    KeyStore keyStore = KeyStore.getInstance(type);
                    fis = new FileInputStream(location);
                    if (log.isDebugEnabled()) {
                        log.debug(name + " Loading Identity Keystore from : " + location);
                    }

                    keyStore.load(fis, storePassword.toCharArray());

                    KeyManagerFactory kmfactory = KeyManagerFactory.getInstance(
                               KeyManagerFactory.getDefaultAlgorithm());
                    kmfactory.init(keyStore, keyPassword.toCharArray());
                    keymanagers = kmfactory.getKeyManagers();
                    if (log.isInfoEnabled() && keymanagers != null) {
                        for (KeyManager keymanager: keymanagers) {
                            if (keymanager instanceof X509KeyManager) {
                                X509KeyManager x509keymanager = (X509KeyManager) keymanager;
                                Enumeration<String> en = keyStore.aliases();
                                while (en.hasMoreElements()) {
                                    String s = en.nextElement();
                                    X509Certificate[] certs = x509keymanager.getCertificateChain(s);
                                    if (certs==null) continue;
                                    for (X509Certificate cert: certs) {
                                        log.debug(name + " Subject DN: " + cert.getSubjectDN());
                                        log.debug(name + " Issuer DN: " + cert.getIssuerDN());
                                    }
                                }
                            }
                        }
                    }

                } catch (GeneralSecurityException gse) {
                    log.error(name + " Error loading Key store : " + location, gse);
                    throw new AxisFault("Error loading Key store : " + location, gse);
                } catch (IOException ioe) {
                    log.error(name + " Error opening Key store : " + location, ioe);
                    throw new AxisFault("Error opening Key store : " + location, ioe);
                } finally {
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (IOException ignore) {}
                    }
                }
            }

            if (trustStoreEl != null) {

                TrustStoreHolder trustStoreHolder = TrustStoreHolder.getInstance();
                FileInputStream fis = null;
                String location = getValueOfElementWithLocalName(trustStoreEl, "Location");
                KeyStore trustStore;

                try {
                    if (trustStoreHolder.getClientTrustStore() == null) {

                        String type = getValueOfElementWithLocalName(trustStoreEl, "Type");
                        OMElement storePasswordEl = trustStoreEl.getFirstChildWithName(new QName("Password"));

                        if (storePasswordEl == null) {
                            throw new AxisFault("Cannot proceed because Password element is missing in TrustStore");
                        }

                        String storePassword = SecureVaultValueReader.getSecureVaultValue(secretResolver, storePasswordEl);
                        trustStore = KeyStore.getInstance(type);
                        fis = new FileInputStream(location);

                        if (log.isDebugEnabled()) {
                            log.debug(name + " Loading Trust Keystore from : " + location);
                        }

                        trustStore.load(fis, storePassword.toCharArray());
                        trustStoreHolder.setClientTrustStore(trustStore);
                    } else {
                        trustStore = trustStoreHolder.getClientTrustStore();
                    }

                    TrustManagerFactory trustManagerfactory = TrustManagerFactory.getInstance(
                            TrustManagerFactory.getDefaultAlgorithm());
                    trustManagerfactory.init(trustStore);
                    trustManagers = trustManagerfactory.getTrustManagers();

                } catch (GeneralSecurityException gse) {
                    log.error(name + " Error loading Key store : " + location, gse);
                    throw new AxisFault("Error loading Key store : " + location, gse);
                } catch (IOException ioe) {
                    log.error(name + " Error opening Key store : " + location, ioe);
                    throw new AxisFault("Error opening Key store : " + location, ioe);
                } finally {
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (IOException ignore) {}
                    }
                }
            }
            final String s = cientAuthEl != null ? cientAuthEl.getText() : null;
            final SSLClientAuth clientAuth;
            if ("optional".equalsIgnoreCase(s)) {
                clientAuth = SSLClientAuth.OPTIONAL;
            } else if ("require".equalsIgnoreCase(s)) {
                clientAuth = SSLClientAuth.REQUIRED;
            } else {
                clientAuth = null;
            }

            String[] httpsProtocols = null;
            final String configuredHttpsProtocols =
                       httpsProtocolsEl != null ? httpsProtocolsEl.getText() : null;
            if (configuredHttpsProtocols != null && configuredHttpsProtocols.trim().length() != 0) {
                String[] configuredValues = configuredHttpsProtocols.trim().split(",");
                List<String> protocolList = new ArrayList<String>(configuredValues.length);
                for (String protocol : configuredValues) {
                    if (!protocol.trim().isEmpty()) {
                        protocolList.add(protocol.trim());
                    }
                }

                httpsProtocols = protocolList.toArray(new String[protocolList.size()]);
            }

            String[] preferredCiphers = null;
            final String configuredWeakCiphers =
                    preferredCiphersEl != null ? preferredCiphersEl.getText() : null;
            if (configuredWeakCiphers != null && configuredWeakCiphers.trim().length() != 0) {
                String[] configuredValues = configuredWeakCiphers.trim().split(",");
                List<String> ciphersList = new ArrayList<String>(configuredValues.length);
                for (String cipher : configuredValues) {
                    cipher = cipher.trim();
                    if (!cipher.isEmpty()) {
                        ciphersList.add(cipher);
                    }
                }

                preferredCiphers = ciphersList.toArray(new String[ciphersList.size()]);
            }

            try {
                final String sslProtocolValue = sslProtocol != null ? sslProtocol : "TLS";
                SSLContext sslContext = SSLContext.getInstance(sslProtocolValue);
                sslContext.init(keymanagers, trustManagers, null);

                ServerSSLSetupHandler sslSetupHandler = (clientAuth != null || httpsProtocols != null
                        || preferredCiphers != null) ?
                        new ServerSSLSetupHandler(clientAuth, httpsProtocols, verificationManager, preferredCiphers) :
                        null;

                return new SSLContextDetails(sslContext, sslSetupHandler);
            } catch (GeneralSecurityException gse) {
                log.error(name + " Unable to create SSL context with the given configuration", gse);
                throw new AxisFault("Unable to create SSL context with the given configuration", gse);
            }
        }

        public ServerConnFactoryBuilder parseSSL() throws AxisFault {
            Parameter keyParam = transportIn.getParameter("keystore");
            Parameter trustParam = transportIn.getParameter("truststore");
            Parameter clientAuthParam = transportIn.getParameter("SSLVerifyClient");
            Parameter httpsProtocolsParam = transportIn.getParameter("HttpsProtocols");
            final Parameter sslpParameter = transportIn.getParameter("SSLProtocol");
            Parameter preferredCiphersParam = transportIn.getParameter(NhttpConstants.PREFERRED_CIPHERS);
            final String sslProtocol = sslpParameter != null ? sslpParameter.getValue().toString() : "TLS";
            OMElement keyStoreEl = keyParam != null ? keyParam.getParameterElement().getFirstElement() : null;
            OMElement trustStoreEl = trustParam != null ? trustParam.getParameterElement().getFirstElement() : null;
            OMElement clientAuthEl = clientAuthParam != null ? clientAuthParam.getParameterElement() : null;
            OMElement httpsProtocolsEl = httpsProtocolsParam != null ? httpsProtocolsParam.getParameterElement() : null;
            OMElement preferredCiphersEl = preferredCiphersParam != null ? preferredCiphersParam.getParameterElement() : null;

            final Parameter cvp = transportIn.getParameter("CertificateRevocationVerifier");
            final String cvEnable = cvp != null ?
                                    cvp.getParameterElement().getAttribute(new QName("enable")).getAttributeValue() : null;

            if ("true".equalsIgnoreCase(cvEnable)) {
                String cacheSizeString = cvp.getParameterElement().getFirstChildWithName(new QName("CacheSize")).getText();
                String cacheDelayString = cvp.getParameterElement().getFirstChildWithName(new QName("CacheDelay")).getText();
                Integer cacheSize = null;
                Integer cacheDelay = null;
                try {
                    cacheSize = new Integer(cacheSizeString);
                    cacheDelay = new Integer(cacheDelayString);
                }
                catch (NumberFormatException e) {
                    throw new AxisFault("Cache size or Cache delay values are malformed", e);
                }

                // Checking whether the full certificate chain validation is enabled or not.
                boolean isFullCertChainValidationEnabled = true;
                boolean isCertExpiryValidationEnabled = false;
                OMElement fullCertChainValidationConfig = cvp.getParameterElement()
                        .getFirstChildWithName(new QName("FullChainValidation"));
                OMElement certExpiryValidationConfig = cvp.getParameterElement()
                        .getFirstChildWithName(new QName("ExpiryValidation"));

                if (fullCertChainValidationConfig != null
                        && StringUtils.equals("false", fullCertChainValidationConfig.getText())) {
                    isFullCertChainValidationEnabled = false;
                }

                if (certExpiryValidationConfig != null && StringUtils.equals("true", certExpiryValidationConfig.getText())) {
                    isCertExpiryValidationEnabled = true;
                }

                certificateVerifier = new CertificateVerificationManager(cacheSize, cacheDelay,
                        isFullCertChainValidationEnabled, isCertExpiryValidationEnabled);
            }

            ssl = createSSLContext(keyStoreEl, trustStoreEl, clientAuthEl, httpsProtocolsEl, preferredCiphersEl,
                    certificateVerifier, sslProtocol);
            return this;
        }

        public ServerConnFactoryBuilder parseMultiProfileSSL() throws AxisFault {

            TransportInDescription loadedTransportIn = loadMultiProfileSSLConfig();
            if (loadedTransportIn == null)
                return this;

            Parameter profileParam    = transportIn.getParameter("SSLProfiles");
            OMElement profilesEl = profileParam.getParameterElement();
            SecretResolver secretResolver = SecretResolverFactory.create(profilesEl, true);
            Iterator<?> profiles = profilesEl.getChildrenWithName(new QName("profile"));

            while (profiles.hasNext()) {
                OMElement profileEl = (OMElement) profiles.next();
                OMElement bindAddressEl = profileEl.getFirstChildWithName(new QName("bindAddress"));
                if (bindAddressEl == null) {
                    String msg = "SSL profile must define a bind address";
                    log.error(name + " " + msg);
                    throw new AxisFault(msg);
                }
                InetSocketAddress address = new InetSocketAddress(bindAddressEl.getText(), host.getPort());

                OMElement keyStoreEl = profileEl.getFirstChildWithName(new QName("KeyStore"));
                OMElement trustStoreEl = profileEl.getFirstChildWithName(new QName("TrustStore"));
                OMElement clientAuthEl = profileEl.getFirstChildWithName(new QName("SSLVerifyClient"));
                OMElement httpsProtocolsEl = profileEl.getFirstChildWithName(new QName("HttpsProtocols"));
                OMElement preferredCiphersEl = profileEl.getFirstChildWithName(new QName(NhttpConstants.PREFERRED_CIPHERS));
                final Parameter sslpParameter = transportIn.getParameter("SSLProtocol");
                final String sslProtocol = sslpParameter != null ? sslpParameter.getValue().toString() : "TLS";

                /* If multi SSL profiles are configured, checking whether the certificate revocation verifier is
                   configured and full certificate chain validation is enabled or not. */
                if (profileEl.getFirstChildWithName(new QName("CertificateRevocationVerifier")) != null) {

                    Integer cacheSize = null;
                    Integer cacheDelay = null;

                    OMElement revocationVerifierConfig = profileEl
                            .getFirstChildWithName(new QName("CertificateRevocationVerifier"));
                    OMElement revocationEnabled = revocationVerifierConfig
                            .getFirstChildWithName(new QName("Enable"));

                    if (revocationEnabled != null && "true".equals(revocationEnabled.getText())) {
                        String cacheSizeString = revocationVerifierConfig
                                .getFirstChildWithName(new QName("CacheSize")).getText();
                        String cacheDelayString = revocationVerifierConfig
                                .getFirstChildWithName(new QName("CacheDelay")).getText();

                        try {
                            cacheSize = new Integer(cacheSizeString);
                            cacheDelay = new Integer(cacheDelayString);
                        } catch (NumberFormatException e) {
                            throw new AxisFault("Cache size or Cache delay values are malformed", e);
                        }
                    }

                    boolean isFullCertChainValidationEnabled = true;
                    boolean isCertExpiryValidationEnabled = false;

                    OMElement fullCertChainValidationConfig = revocationVerifierConfig
                            .getFirstChildWithName(new QName("FullChainValidation"));

                    OMElement certExpiryValidationConfig = revocationVerifierConfig
                            .getFirstChildWithName(new QName("ExpiryValidation"));

                    if (fullCertChainValidationConfig != null
                            && StringUtils.equals("false", fullCertChainValidationConfig.getText())) {
                        isFullCertChainValidationEnabled = false;
                    }

                    if (certExpiryValidationConfig != null
                            && StringUtils.equals("true", certExpiryValidationConfig.getText())) {
                        isCertExpiryValidationEnabled = true;
                    }

                    if (fullCertChainValidationConfig != null
                            && StringUtils.equals("false", fullCertChainValidationConfig.getText())) {
                        isFullCertChainValidationEnabled = false;
                    }

                    certificateVerifier = new CertificateVerificationManager(cacheSize, cacheDelay,
                            isFullCertChainValidationEnabled, isCertExpiryValidationEnabled);
                }

                SSLContextDetails ssl = createSSLContext(keyStoreEl, trustStoreEl, clientAuthEl, httpsProtocolsEl,
                        preferredCiphersEl, certificateVerifier, sslProtocol, secretResolver);
                if (sslByIPMap == null) {
                    sslByIPMap = new HashMap<InetSocketAddress, SSLContextDetails>();
                }
                sslByIPMap.put(address, ssl);
            }
            return this;
        }

        /**
         * Loads MultiProfileSSLConfiguration when the configuration is in a different file
         * than axis2.xml. If the configuration file path is in axis2.xml and its successfully loaded, it will be
         * added to transportIn as "SSLProfiles" parameter or else if it isn't loaded it will return null.
         * @return
         */
        public TransportInDescription loadMultiProfileSSLConfig () {

            Parameter profilePathParam = transportIn.getParameter("dynamicSSLProfilesConfig");

            //Custom SSL Profile configuration file not configured
            if (profilePathParam == null) {
                //Custom SSL Profiles configured in Axis2 configuration
                if (transportIn.getParameter("SSLProfiles") != null) {
                    return transportIn;
                } else {
                    return null;
                }
            }

            ////Custom SSL Profile configured. Ignore Axis2 configurations
            OMElement pathEl = profilePathParam.getParameterElement();
            String path = pathEl.getFirstChildWithName(new QName("filePath")).getText();

            try {
                if (path != null) {

                    String separator = path.startsWith(System.getProperty("file.separator")) ?
                                       "" : System.getProperty("file.separator");
                    String fullPath = System.getProperty("user.dir") + separator + path;

                    OMElement profileEl = new StAXOMBuilder(fullPath).getDocumentElement();
                    Parameter profileParam = new Parameter();
                    profileParam.setParameterElement(profileEl);
                    profileParam.setName("SSLProfiles");
                    profileParam.setValue(profileEl);

                    transportIn.addParameter(profileParam);
                    log.info("SSLProfile configuration is loaded from path: " + fullPath);

                    return transportIn;
                }
            } catch (Exception e) {
                log.error("Could not load SSLProfileConfig from file path: " + path, e);
            }
            return null;
        }

        public ServerConnFactory build(final HttpParams params) throws AxisFault {
            if (ssl != null || sslByIPMap != null) {
                String port = ParamUtils.getOptionalParam(transportIn, "port");
                if (port != null) {
                    return new ServerConnFactory(ssl, sslByIPMap, params, Integer.parseInt(port));
                } else {
                    return new ServerConnFactory(ssl, sslByIPMap, params);
                }
            } else {
                return new ServerConnFactory(params);
            }
        }

        private String getValueOfElementWithLocalName(OMElement element, String localName) {
            Iterator iterator = element.getChildrenWithLocalName(localName);
            String value = null;
            Object obj = iterator.next();
            if (obj instanceof OMElement) {
                value = ((OMElement) obj).getText();
            }
            return value;
        }

    }