Add optional TLS SNI initiator support (quickfix-j#277)

* add address to SNI init log output
* add UseSNI opt-in parameter
* add doc for the UseSNI config parameter
* change to parametrized logging
* minor changes to comments and logging
* corrected SNI (indication) in doc

Co-authored-by: Christoph John <christoph.john@macd.com>

quickfixj-core/src/main/doc/usermanual/usage/configuration.html

@@ -692,6 +692,12 @@ <H3>QuickFIX Settings</H3>
     <TD></TD>
     <TD><a href="https://docs.oracle.com/javase/6/docs/technotes/guides/security/SunProviders.html">Java default cipher suites</a></TD>
   </TR>
+  <TR ALIGN="left" VALIGN="middle">
+    <TD valign="top"> <I>UseSNI</I></TD>
+    <TD>Configures the SSL engine to use Server Name Indication. This option is only useful to initiators.</TD>
+    <TD>Y<BR>N</TD>
+    <TD>N</TD>
+  </TR>
 
   <TR ALIGN="center" VALIGN="middle">
     <TD COLSPAN="4" class="subsection"><A NAME="Security">Socks Proxy Options (Initiator only)</A></TD>
@@ -1279,7 +1285,7 @@ <H3>QuickFIX Settings</H3>
   </TABLE>
 
   <H3><A NAME="Invalid vs Garbled Messages">Rejecting Invalid vs Garbled Messages</A></H3>
-  
+
   <p>
       There are mainly two settings that influence QFJ's rejection behaviour:
   </p>
@@ -1292,9 +1298,9 @@ <H3><A NAME="Invalid vs Garbled Messages">Rejecting Invalid vs Garbled Messages<
       While the first applies to messages that fail data dictionary validation,
       the latter applies to messages that fail basic validity checks on the FIX protocol level.
   </p>
-  
+
   <H4>Setting RejectInvalidMessage</H4>
-  
+
   <p>
       If RejectInvalidMessage is set to
   </p>

quickfixj-core/src/main/java/quickfix/mina/initiator/IoSessionInitiator.java

@@ -192,6 +192,7 @@ private SSLFilter installSslFilter(CompositeIoFilterChainBuilder ioFilterChainBu
                     : SSLSupport.getDefaultCipherSuites(sslContext));
             sslFilter.setEnabledProtocols(sslConfig.getEnabledProtocols() != null ? sslConfig.getEnabledProtocols()
                     : SSLSupport.getSupportedProtocols(sslContext));
+            sslFilter.setUseSNI(sslConfig.isUseSNI());
             ioFilterChainBuilder.addLast(SSLSupport.FILTER_NAME, sslFilter);
             return sslFilter;
         }

quickfixj-core/src/main/java/quickfix/mina/ssl/SSLConfig.java

@@ -36,6 +36,7 @@ public class SSLConfig {
 	private String[] enabledProtocols;
 	private String[] enabledCipherSuites;
 	private boolean needClientAuth;
+	private boolean useSNI;
 
 	@Override
 	public boolean equals(Object obj) {
@@ -81,6 +82,8 @@ public boolean equals(Object obj) {
 			return false;
 		if (!Arrays.equals(trustStorePassword, other.trustStorePassword))
 			return false;
+		if(useSNI != other.useSNI)
+			return false;
 		if (trustStoreType == null) {
 			return other.trustStoreType == null;
 		} else return trustStoreType.equals(other.trustStoreType);
@@ -149,6 +152,10 @@ public boolean isNeedClientAuth() {
 		return needClientAuth;
 	}
 
+	public boolean isUseSNI() {
+		return useSNI;
+	}
+
 	public void setEnabledCipherSuites(String[] enabledCipherSuites) {
 		this.enabledCipherSuites = enabledCipherSuites;
 	}
@@ -177,6 +184,10 @@ public void setNeedClientAuth(boolean needClientAuth) {
 		this.needClientAuth = needClientAuth;
 	}
 
+	public void setUseSNI(boolean useSNI) {
+		this.useSNI = useSNI;
+	}
+
 	public void setTrustManagerFactoryAlgorithm(String trustManagerFactoryAlgorithm) {
 		this.trustManagerFactoryAlgorithm = trustManagerFactoryAlgorithm;
 	}

quickfixj-core/src/main/java/quickfix/mina/ssl/SSLFilter.java

@@ -19,16 +19,26 @@
 
 package quickfix.mina.ssl;
 
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
 import javax.net.ssl.SSLContext;
 
+import javax.net.ssl.SSLException;
+import org.apache.mina.core.filterchain.IoFilterChain;
+import org.apache.mina.core.session.IoSession;
 import org.apache.mina.filter.ssl.SslFilter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * An extended SSL filter based on MINA {@link SslFilter} that disables setting
- * enabled cipher suites via default method.
+ * An extended SSL filter based on MINA {@link SslFilter} that applies
+ * some adaptations.
  */
 public class SSLFilter extends SslFilter {
 
+    private final Logger log = LoggerFactory.getLogger(getClass());
+    private boolean useSNI;
+
     public SSLFilter(SSLContext sslContext, boolean autoStart) {
         super(sslContext, autoStart);
     }
@@ -38,8 +48,8 @@ public SSLFilter(SSLContext sslContext) {
     }
 
     /**
-     * This method is called from {@link SslFilter#onPreAdd} every time new
-     * session is created which makes impossible to override enabled cipher
+     * Called from {@link SslFilter#onPreAdd} every time a new
+     * session is created which makes it impossible to override enabled cipher
      * suites configuration.
      */
     @Override
@@ -49,4 +59,30 @@ public void setEnabledCipherSuites(String[] cipherSuites) {
     public void setCipherSuites(String[] cipherSuites) {
         super.setEnabledCipherSuites(cipherSuites);
     }
+
+    /**
+     * Called before filter is added into the chain.
+     * We activate Server Name Indication if it is enabled in the session config.
+     */
+    @Override
+    public void onPreAdd(IoFilterChain parent, String name, NextFilter nextFilter)
+        throws SSLException {
+
+        if (useSNI) {
+            IoSession session = parent.getSession();
+            SocketAddress remoteAddress = session.getRemoteAddress();
+
+            if (remoteAddress instanceof InetSocketAddress) {
+                // activate the SNI support in the JSSE SSLEngine
+                log.info("Activating TLS SNI support for peer address: {}", remoteAddress);
+                session.setAttribute(PEER_ADDRESS, remoteAddress);
+            }
+        }
+
+        super.onPreAdd(parent, name, nextFilter);
+    }
+
+    public void setUseSNI(boolean useSNI) {
+        this.useSNI = useSNI;
+    }
 }

quickfixj-core/src/main/java/quickfix/mina/ssl/SSLSupport.java

@@ -39,6 +39,7 @@ public class SSLSupport {
     public static final String SETTING_TRUST_MANAGER_FACTORY_ALGORITHM = "TrustManagerFactoryAlgorithm";
     public static final String SETTING_TRUST_STORE_TYPE = "TrustStoreType";
     public static final String SETTING_NEED_CLIENT_AUTH = "NeedClientAuth";
+    public static final String SETTING_USE_SNI = "UseSNI";
     public static final String SETTING_ENABLED_PROTOCOLS = "EnabledProtocols";
     public static final String SETTING_CIPHER_SUITES = "CipherSuites";
     static final String DEFAULT_STORE_TYPE = "JKS";
@@ -110,6 +111,7 @@ public static SSLConfig getSslConfig(SessionSettings sessionSettings, SessionID
         sslConfig.setEnabledCipherSuites(getEnabledCipherSuites(sessionSettings, sessionID));
         sslConfig.setEnabledProtocols(getEnabledProtocols(sessionSettings, sessionID));
         sslConfig.setNeedClientAuth(isNeedClientAuth(sessionSettings, sessionID));
+        sslConfig.setUseSNI(isUseSNI(sessionSettings, sessionID));
 
         return sslConfig;
     }
@@ -147,4 +149,8 @@ public static String getTrustStoreType(SessionSettings sessionSettings, SessionI
     public static boolean isNeedClientAuth(SessionSettings sessionSettings, SessionID sessionID) {
         return "Y".equals(getString(sessionSettings, sessionID, SETTING_NEED_CLIENT_AUTH, "N"));
     }
+
+    public static boolean isUseSNI(SessionSettings sessionSettings, SessionID sessionID) {
+        return "Y".equals(getString(sessionSettings, sessionID, SETTING_USE_SNI, "N"));
+    }
 }