chat for a single user actually works

pom.xml

@@ -61,9 +61,12 @@
     <dependency>
   <groupId>io.netty</groupId>
   <artifactId>netty-tcnative-boringssl-static</artifactId>
-  <version>2.0.59.Final</version>
   </dependency>
-
+<dependency>
+    <groupId>javax.xml.bind</groupId>
+    <artifactId>jaxb-api</artifactId>
+    <version>2.4.0-b180830.0359</version>
+</dependency>
   </dependencies>
 
   <build>

src/main/java/cx/lehmann/gemini/gemini/MainVerticle.java

@@ -1,6 +1,10 @@
 package cx.lehmann.gemini.gemini;
 
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.security.cert.Certificate;
+import java.security.cert.CertificateEncodingException;
+import java.security.cert.X509Certificate;
 import java.util.List;
 
 import javax.net.ssl.SSLPeerUnverifiedException;
@@ -9,20 +13,27 @@ import io.vertx.core.AbstractVerticle;
 import io.vertx.core.Promise;
 import io.vertx.core.http.ClientAuth;
 import io.vertx.core.net.NetServerOptions;
+import io.vertx.core.net.NetSocket;
 //import io.vertx.core.net.OpenSSLEngineOptions;
 import io.vertx.core.net.PemKeyCertOptions;
 import io.vertx.core.net.PemTrustOptions;
 import io.vertx.core.net.TrustOptions;
 
+import javax.xml.bind.DatatypeConverter;
+
+//import sun.security.x509.X509Cert;
+
 public class MainVerticle extends AbstractVerticle {
 
+  NetSocket conn2=null;
+
   @Override
   public void start(Promise<Void> startPromise) throws Exception {
     NetServerOptions options=new NetServerOptions();
 
     String certPath="c:/temp/cert.pem";
     
-    TrustOptions trustOptions=new PemTrustOptions();
+//    TrustOptions trustOptions=new PemTrustOptions();
     options.setPemKeyCertOptions(new PemKeyCertOptions()
         .setCertPath(certPath)
         .setKeyPath(certPath))
@@ -31,6 +42,7 @@ public class MainVerticle extends AbstractVerticle {
 //    .setOpenSslEngineOptions(new OpenSSLEngineOptions())
     .setClientAuth(ClientAuth.REQUIRED);
 
+
     vertx.createNetServer(options).connectHandler(conn -> {
       conn.handler(event -> {
         System.out.println("accepted connection:"+conn.remoteAddress());
@@ -40,20 +52,35 @@ public class MainVerticle extends AbstractVerticle {
           conn.close();
         } else {
           url=url.substring(0, url.length()-2);
-//          conn.write("60 cert required\r\n");
-          conn.write("20 text/gemini\r\n");
-          conn.write("url:"+url);
-          conn.write("\n");
-          try {
-            List<Certificate> certs=conn.peerCertificates();
-            System.out.println("get certs");
-            System.out.println("number of certs:"+certs.size());
-            Certificate cert=certs.get(0);
-            conn.write(cert.toString());
-          } catch (SSLPeerUnverifiedException ex) {
-            ex.printStackTrace();
+          System.out.println("url:"+url);
+          String path=url.substring(18);
+          System.out.println("path:"+path);
+          if (path.startsWith("/post")) {
+            System.out.println("post");
+            try {
+              List<Certificate> certs = conn.peerCertificates();
+              Certificate cert = certs.get(0);
+              X509Certificate certX509 = (X509Certificate) cert;
+              String clientHash = getThumbprint(certX509);
+              System.out.println("cert");
+              if (!url.contains("?")) {
+                conn.write("10 please enter your chat message\r\n");
+              } else {
+                String message = url.substring(url.indexOf('?') + 1);
+                conn.write("20 text/gemini\r\n");
+                conn.write("message was sent\n");
+                conn.write("=> /post post another message\n");
+                conn2.write(clientHash+":"+message+"\n");
+              }
+            } catch (SSLPeerUnverifiedException | CertificateEncodingException | NoSuchAlgorithmException ex) {
+              ex.printStackTrace();
+            }
+            conn.close();
+          } else {
+            System.out.println("conn2");
+            conn2=conn;
+            conn2.write("20 text/gemini\r\n");
           }
-          conn.close();
         }
       }
         );
@@ -66,4 +93,14 @@ public class MainVerticle extends AbstractVerticle {
           }
         });
     }
-  }
+
+    private static String getThumbprint(X509Certificate cert)
+        throws NoSuchAlgorithmException, CertificateEncodingException {
+      MessageDigest md = MessageDigest.getInstance("SHA-256");
+      byte[] der = cert.getEncoded();
+      md.update(der);
+      byte[] digest = md.digest();
+      String digestHex = DatatypeConverter.printHexBinary(digest);
+      return digestHex.toLowerCase();
+    }
+}