First commit

.vscode/launch.json

@@ -0,0 +1,15 @@
+{
+	// Use IntelliSense to learn about possible attributes.
+	// Hover to view descriptions of existing attributes.
+	// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+	"version": "0.2.0",
+	"configurations": [
+		{
+			"name": "Launch Package",
+			"type": "go",
+			"request": "launch",
+			"mode": "debug",
+			"program": "${workspaceFolder}/main.go"
+		}
+	]
+}

client_script.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+var_file="./var_file"
+
+if [ -f "$var_file" ] 
+then
+	echo "file exists"
+	var=$(cat $var_file)
+else
+	"file does not exist"
+	var=10
+fi
+
+echo "Value of var: " $var
+
+let var=$var+1
+echo $var ": Hallo Freunde der Sonne" | openssl s_client -connect localhost:8080
+
+
+echo $var > $var_file

go.mod

@@ -0,0 +1,3 @@
+module tls_server
+
+go 1.19

main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"tls_server/server"
+)
+
+func main() {
+	server.RunServer()
+}

server/server.go

@@ -0,0 +1,90 @@
+package server
+
+import (
+	"bufio"
+	"crypto/tls"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"os"
+	"strconv"
+)
+
+const (
+	port     uint = 8080
+	certFile      = "/home/m/.local_ca/localhost.crt"
+	keyFile       = "/home/m/.local_ca/localhost.key"
+)
+
+func RunServer() error {
+	tls_cfg, err := configTls()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(-1)
+	}
+
+	listener, err := listen(tls_cfg)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(-1)
+	}
+
+	for {
+		connection, err := listener.Accept()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(-1)
+		}
+
+		go handleConnection(connection)
+	}
+}
+
+func configTls() (*tls.Config, error) {
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		log.Println("Error while loading x509 key pair")
+		log.Println(err)
+		return nil, err
+	}
+
+	return &tls.Config{Certificates: []tls.Certificate{cert}}, nil
+}
+
+func listen(tls_config *tls.Config) (net.Listener, error) {
+	listeningOnAddr := "localhost:" + strconv.FormatUint(uint64(port), 10)
+
+	listener, err := tls.Listen("tcp", listeningOnAddr, tls_config)
+	if err != nil {
+		return nil, err
+	}
+	fmt.Println("We started to listen on port", port)
+
+	return listener, nil
+}
+
+func handleConnection(connection net.Conn) {
+
+	testReader := *bufio.NewReader(connection)
+
+	for {
+
+		readBuf := make([]byte, 10)
+
+		if n, err := testReader.Read(readBuf); n > 0 {
+			fmt.Printf("Type of connection: %T\n", connection)
+			fmt.Println(n, " bytes read: ", readBuf)
+
+			if n > 0 {
+				switch err {
+				case nil:
+				case io.EOF:
+					fmt.Println(err)
+				default:
+					fmt.Println(err)
+				}
+			}
+		}
+	}
+}

var_file

@@ -0,0 +1 @@
+11