Normalize SSL domain name from hostname when it's a FQDM, close AsyncHttpClient#1505

Motivation:

When hostname is a FQDN, AHC crashes when performing TLS handshake.

Modification:

Remove the trailing dot when configuring the SNI/hostname verification
hostname.

Result:

Handshake successful with FQDN

Author: slandelle

client/src/main/java/org/asynchttpclient/netty/ssl/DefaultSslEngineFactory.java

@@ -58,7 +58,7 @@ private SslContext buildSslContext(AsyncHttpClientConfig config) throws SSLExcep
   @Override
   public SSLEngine newSslEngine(AsyncHttpClientConfig config, String peerHost, int peerPort) {
     // FIXME should be using ctx allocator
-    SSLEngine sslEngine = sslContext.newEngine(ByteBufAllocator.DEFAULT, peerHost, peerPort);
+    SSLEngine sslEngine = sslContext.newEngine(ByteBufAllocator.DEFAULT, domain(peerHost), peerPort);
     configureSslEngine(sslEngine, config);
     return sslEngine;
   }

client/src/main/java/org/asynchttpclient/netty/ssl/JsseSslEngineFactory.java

@@ -28,7 +28,7 @@ public JsseSslEngineFactory(SSLContext sslContext) {
 
   @Override
   public SSLEngine newSslEngine(AsyncHttpClientConfig config, String peerHost, int peerPort) {
-    SSLEngine sslEngine = sslContext.createSSLEngine(peerHost, peerPort);
+    SSLEngine sslEngine = sslContext.createSSLEngine(domain(peerHost), peerPort);
     configureSslEngine(sslEngine, config);
     return sslEngine;
   }

client/src/main/java/org/asynchttpclient/netty/ssl/SslEngineFactoryBase.java

@@ -21,6 +21,13 @@
 
 public abstract class SslEngineFactoryBase implements SslEngineFactory {
 
+  protected String domain(String hostname) {
+    int fqdnLength = hostname.length() - 1;
+    return hostname.charAt(fqdnLength) == '.' ?
+            hostname.substring(0, fqdnLength) :
+            hostname;
+  }
+
   protected void configureSslEngine(SSLEngine sslEngine, AsyncHttpClientConfig config) {
     sslEngine.setUseClientMode(true);
     if (!config.isDisableHttpsEndpointIdentificationAlgorithm()) {