fix build for jdk6

pom.xml

@@ -311,6 +311,43 @@
 	</dependencies>
 
 	<profiles>
+        <profile>
+            <id>jdk6</id>
+            <activation>
+                <jdk>1.6</jdk>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <version>2.22.1</version>
+                    </plugin>
+                </plugins>
+            </build>
+            <dependencies>
+                <dependency>
+                    <groupId>javax.el</groupId>
+                    <artifactId>javax.el-api</artifactId>
+                    <version>3.0.0</version>
+                </dependency>
+            </dependencies>
+            <!-- workaround for non-overlapping TLS versions in JDK6 and central repo
+             https://central.sonatype.org/articles/2018/May/04/discontinued-support-for-tlsv11-and-below/ -->
+            <repositories>
+                <repository>
+                    <id>repo1</id>
+                    <url>http://repo1.maven.org/maven2</url>
+                </repository>
+            </repositories>
+            <pluginRepositories>
+                <pluginRepository>
+                    <id>repo1</id>
+                    <url>http://repo1.maven.org/maven2</url>
+                </pluginRepository>
+            </pluginRepositories>
+        </profile>
+
 		<profile>
 			<id>hibernate5</id>
 			<activation>

src/main/java/ysoserial/exploit/RMIRegistryExploit.java

@@ -9,11 +9,7 @@ import java.rmi.registry.Registry;
 import java.rmi.server.RMIClientSocketFactory;
 import java.security.cert.X509Certificate;
 import java.util.concurrent.Callable;
-import javax.net.ssl.SSLContext;
+import javax.net.ssl.*;
-import javax.net.ssl.SSLEngine;
-import javax.net.ssl.SSLSocketFactory;
-import javax.net.ssl.TrustManager;
-import javax.net.ssl.X509ExtendedTrustManager;
 
 import ysoserial.payloads.CommonsCollections1;
 import ysoserial.payloads.ObjectPayload;
@@ -30,15 +26,11 @@ import ysoserial.secmgr.ExecCheckingSecurityManager;
  */
 @SuppressWarnings({"rawtypes", "unchecked"})
 public class RMIRegistryExploit {
-	private static class TrustAllSSL extends X509ExtendedTrustManager {
+	private static class TrustAllSSL implements X509TrustManager {
 		private static final X509Certificate[] ANY_CA = {};
 		public X509Certificate[] getAcceptedIssuers() { return ANY_CA; }
 		public void checkServerTrusted(final X509Certificate[] c, final String t) { /* Do nothing/accept all */ }
 		public void checkClientTrusted(final X509Certificate[] c, final String t) { /* Do nothing/accept all */ }
-		public void checkServerTrusted(final X509Certificate[] c, final String t, final SSLEngine e) { /* Do nothing/accept all */ }
-		public void checkServerTrusted(final X509Certificate[] c, final String t, final Socket e) { /* Do nothing/accept all */ }
-		public void checkClientTrusted(final X509Certificate[] c, final String t, final SSLEngine e) { /* Do nothing/accept all */ }
-		public void checkClientTrusted(final X509Certificate[] c, final String t, final Socket e) { /* Do nothing/accept all */ }
 	}
 
 	private static class RMISSLClientSocketFactory implements RMIClientSocketFactory {
@@ -61,7 +53,7 @@ public class RMIRegistryExploit {
 		Registry registry = LocateRegistry.getRegistry(host, port);
 		final String className = CommonsCollections1.class.getPackage().getName() +  "." + args[2];
 		final Class<? extends ObjectPayload> payloadClass = (Class<? extends ObjectPayload>) Class.forName(className);
-		
+
 		// test RMI registry connection and upgrade to SSL connection on fail
 		try {
 			registry.list();