Add support for HTTPS for API

Requires entries 'sslKeystorePathname' and 'sslKeystorePassword'
in settings.json.

With SSL enabled, API will auto-detect HTTP or HTTPs on the same port.

Included tools/build-keystore.sh to help build keystore from
Let's Encrypt certificates.

src/main/java/org/qortal/api/ApiService.java

@@ -2,15 +2,31 @@ package org.qortal.api;
 
 import io.swagger.v3.jaxrs2.integration.resources.OpenApiResource;
 
+import java.io.InputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.security.KeyStore;
+import java.security.SecureRandom;
 
+import javax.net.ssl.KeyManagerFactory;
+import javax.net.ssl.SSLContext;
+
+import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RedirectPatternRule;
 import org.eclipse.jetty.rewrite.handler.RewriteHandler;
 import org.eclipse.jetty.server.CustomRequestLog;
+import org.eclipse.jetty.server.HttpConfiguration;
+import org.eclipse.jetty.server.HttpConnectionFactory;
+import org.eclipse.jetty.server.OptionalSslConnectionFactory;
 import org.eclipse.jetty.server.RequestLog;
 import org.eclipse.jetty.server.RequestLogWriter;
+import org.eclipse.jetty.server.SecureRequestCustomizer;
 import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.server.SslConnectionFactory;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.InetAccessHandler;
 import org.eclipse.jetty.servlet.DefaultServlet;
@@ -18,6 +34,7 @@ import org.eclipse.jetty.servlet.FilterHolder;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
 import org.eclipse.jetty.servlets.CrossOriginFilter;
+import org.eclipse.jetty.util.ssl.SslContextFactory;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.servlet.ServletContainer;
 import org.qortal.api.resource.AnnotationPostProcessor;
@@ -56,9 +73,58 @@ public class ApiService {
 	public void start() {
 		try {
 			// Create API server
-			InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
-			InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getApiPort());
-			this.server = new Server(endpoint);
+
+			// SSL support if requested
+			String keystorePathname = Settings.getInstance().getSslKeystorePathname();
+			String keystorePassword = Settings.getInstance().getSslKeystorePassword();
+
+			if (keystorePathname != null && keystorePassword != null) {
+				// SSL version
+				if (!Files.isReadable(Path.of(keystorePathname)))
+					throw new RuntimeException("Failed to start SSL API due to broken keystore");
+
+				// BouncyCastle-specific SSLContext build
+				SSLContext sslContext = SSLContext.getInstance("TLS", "BCJSSE");
+				KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("PKIX", "BCJSSE");
+
+				KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType(), "BC");
+
+				try (InputStream keystoreStream = Files.newInputStream(Paths.get(keystorePathname))) {
+					keyStore.load(keystoreStream, keystorePassword.toCharArray());
+				}
+
+				keyManagerFactory.init(keyStore, keystorePassword.toCharArray());
+				sslContext.init(keyManagerFactory.getKeyManagers(), null, new SecureRandom());
+
+				SslContextFactory.Server sslContextFactory = new SslContextFactory.Server();
+				sslContextFactory.setSslContext(sslContext);
+
+				this.server = new Server();
+
+				HttpConfiguration httpConfig = new HttpConfiguration();
+				httpConfig.setSecureScheme("https");
+				httpConfig.setSecurePort(Settings.getInstance().getApiPort());
+
+				SecureRequestCustomizer src = new SecureRequestCustomizer();
+				httpConfig.addCustomizer(src);
+
+				HttpConnectionFactory httpConnectionFactory = new HttpConnectionFactory(httpConfig);
+				SslConnectionFactory sslConnectionFactory = new SslConnectionFactory(sslContextFactory, HttpVersion.HTTP_1_1.asString());
+
+				ServerConnector portUnifiedConnector = new ServerConnector(this.server,
+						new OptionalSslConnectionFactory(sslConnectionFactory, HttpVersion.HTTP_1_1.asString()),
+						sslConnectionFactory,
+						httpConnectionFactory);
+				portUnifiedConnector.setHost(Settings.getInstance().getBindAddress());
+				portUnifiedConnector.setPort(Settings.getInstance().getApiPort());
+
+				this.server.addConnector(portUnifiedConnector);
+			} else {
+				// Non-SSL
+				InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+				InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getApiPort());
+				this.server = new Server(endpoint);
+			}
 
 			// Error handler
 			ErrorHandler errorHandler = new ApiErrorHandler();

src/main/java/org/qortal/settings/Settings.java

@@ -63,6 +63,9 @@ public class Settings {
 	private Boolean apiRestricted;
 	private boolean apiLoggingEnabled = false;
 	private boolean apiDocumentationEnabled = false;
+	// Both of these need to be set for API to use SSL
+	private String sslKeystorePathname = null;
+	private String sslKeystorePassword = null;
 
 	// Specific to this node
 	private boolean wipeUnconfirmedOnStart = false;
@@ -295,6 +298,14 @@ public class Settings {
 		return this.apiDocumentationEnabled;
 	}
 
+	public String getSslKeystorePathname() {
+		return this.sslKeystorePathname;
+	}
+
+	public String getSslKeystorePassword() {
+		return this.sslKeystorePassword;
+	}
+
 	public boolean getWipeUnconfirmedOnStart() {
 		return this.wipeUnconfirmedOnStart;
 	}

tools/build-keystore.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+set -e
+
+# Assumes Let's Encrypt
+
+if [ $# -ne 1 -a $# -ne 3 ]; then
+	echo "usage: ${0%%*/} <domain> [<keystore> <password>]"
+	exit 2
+fi
+
+domain=$1
+keystore=${2:-core-api.keystore}
+pass=${3:-kspassword}
+
+LEdirs=(/usr/local/etc /etc /opt .)
+for LEdir in "${LEdirs[@]}"; do
+	srcdir="${LEdir}/letsencrypt/live/${domain}"
+	if [ -d "$srcdir" ]; then
+		echo "Using certs & keys from ${srcdir}"
+		break;
+	fi
+	unset srcdir
+done
+
+if [ -z "${srcdir}" ]; then
+	echo "Can't find Let's Encrypt folder for ${domain}"
+	exit
+fi
+
+# key & cert
+rm -f "${domain}.p12"
+openssl pkcs12 \
+	-inkey "${srcdir}/privkey.pem" -in "${srcdir}/fullchain.pem" \
+	-export -out "${domain}.p12" -passout pass:"${pass}" \
+	-name "${domain}"
+
+rm -f "${keystore}"
+keytool -importkeystore -noprompt \
+	-srckeystore "${domain}.p12" -srcstoretype PKCS12 -srcstorepass "${pass}" \
+	-destkeystore "${keystore}" -deststorepass "${pass}" -destkeypass "${pass}" \
+	-alias "${domain}"
+
+printf "Built keystore: ${keystore}, with password: ${pass}\nFor settings.json:\n"
+
+printf "\tsslKeystorePathname: \"%s\",\n" "${keystore}"
+printf "\tsslKeystorePassword: \"%s\",\n" "${pass}"