Improve error message for SSL failures

Fixes #803

src/main/java/dan200/computercraft/core/apis/http/NetworkUtils.java

@@ -11,12 +11,19 @@ import dan200.computercraft.core.apis.http.options.AddressRule;
 import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.shared.util.ThreadUtils;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.handler.codec.DecoderException;
+import io.netty.handler.codec.TooLongFrameException;
+import io.netty.handler.codec.http.websocketx.WebSocketHandshakeException;
 import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
+import io.netty.handler.timeout.ReadTimeoutException;
 
+import javax.annotation.Nonnull;
 import javax.net.ssl.SSLException;
+import javax.net.ssl.SSLHandshakeException;
 import javax.net.ssl.TrustManagerFactory;
 import java.net.InetSocketAddress;
 import java.net.URI;
@@ -161,4 +168,29 @@ public final class NetworkUtils
         buffer.readBytes( bytes );
         return bytes;
     }
+
+    @Nonnull
+    public static String toFriendlyError( @Nonnull Throwable cause )
+    {
+        if( cause instanceof WebSocketHandshakeException || cause instanceof HTTPRequestException )
+        {
+            return cause.getMessage();
+        }
+        else if( cause instanceof TooLongFrameException )
+        {
+            return "Message is too large";
+        }
+        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
+        {
+            return "Timed out";
+        }
+        else if( cause instanceof SSLHandshakeException || (cause instanceof DecoderException && cause.getCause() instanceof SSLHandshakeException) )
+        {
+            return "Could not create a secure connection";
+        }
+        else
+        {
+            return "Could not connect";
+        }
+    }
 }

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequest.java

@@ -19,13 +19,10 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
-import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
-import io.netty.handler.codec.TooLongFrameException;
 import io.netty.handler.codec.http.*;
 import io.netty.handler.ssl.SslContext;
-import io.netty.handler.timeout.ReadTimeoutException;
 import io.netty.handler.timeout.ReadTimeoutHandler;
 
 import java.net.InetSocketAddress;
@@ -190,7 +187,7 @@ public class HttpRequest extends Resource<HttpRequest>
                 .remoteAddress( socketAddress )
                 .connect()
                 .addListener( c -> {
-                    if( !c.isSuccess() ) failure( c.cause() );
+                    if( !c.isSuccess() ) failure( NetworkUtils.toFriendlyError( c.cause() ) );
                 } );
 
             // Do an additional check for cancellation
@@ -202,7 +199,7 @@ public class HttpRequest extends Resource<HttpRequest>
         }
         catch( Exception e )
         {
-            failure( "Could not connect" );
+            failure( NetworkUtils.toFriendlyError( e ) );
             if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in HTTP request", e );
         }
     }
@@ -212,29 +209,6 @@ public class HttpRequest extends Resource<HttpRequest>
         if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message );
     }
 
-    void failure( Throwable cause )
-    {
-        String message;
-        if( cause instanceof HTTPRequestException )
-        {
-            message = cause.getMessage();
-        }
-        else if( cause instanceof TooLongFrameException )
-        {
-            message = "Response is too large";
-        }
-        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
-        {
-            message = "Timed out";
-        }
-        else
-        {
-            message = "Could not connect";
-        }
-
-        failure( message );
-    }
-
     void failure( String message, HttpResponseHandle object )
     {
         if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message, object );

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequestHandler.java

@@ -183,7 +183,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
     public void exceptionCaught( ChannelHandlerContext ctx, Throwable cause )
     {
         if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error handling HTTP response", cause );
-        request.failure( cause );
+        request.failure( NetworkUtils.toFriendlyError( cause ) );
     }
 
     private void sendResponse()

src/main/java/dan200/computercraft/core/apis/http/websocket/Websocket.java

@@ -166,7 +166,7 @@ public class Websocket extends Resource<Websocket>
                 .remoteAddress( socketAddress )
                 .connect()
                 .addListener( c -> {
-                    if( !c.isSuccess() ) failure( c.cause().getMessage() );
+                    if( !c.isSuccess() ) failure( NetworkUtils.toFriendlyError( c.cause() ) );
                 } );
 
             // Do an additional check for cancellation
@@ -178,7 +178,7 @@ public class Websocket extends Resource<Websocket>
         }
         catch( Exception e )
         {
-            failure( "Could not connect" );
+            failure( NetworkUtils.toFriendlyError( e ) );
             if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in websocket", e );
         }
     }

src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandler.java

@@ -5,17 +5,13 @@
  */
 package dan200.computercraft.core.apis.http.websocket;
 
-import dan200.computercraft.core.apis.http.HTTPRequestException;
 import dan200.computercraft.core.apis.http.NetworkUtils;
 import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.core.tracking.TrackingField;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.SimpleChannelInboundHandler;
-import io.netty.handler.codec.TooLongFrameException;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.websocketx.*;
-import io.netty.handler.timeout.ReadTimeoutException;
 import io.netty.util.CharsetUtil;
 
 import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
@@ -97,24 +93,7 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object>
     {
         ctx.close();
 
-        String message;
+        String message = NetworkUtils.toFriendlyError( cause );
-        if( cause instanceof WebSocketHandshakeException || cause instanceof HTTPRequestException )
-        {
-            message = cause.getMessage();
-        }
-        else if( cause instanceof TooLongFrameException )
-        {
-            message = "Message is too large";
-        }
-        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
-        {
-            message = "Timed out";
-        }
-        else
-        {
-            message = "Could not connect";
-        }
-
         if( handshaker.isHandshakeComplete() )
         {
             websocket.close( -1, message );