From 3261a436cbd87329ae35e4103ca7642ce54626f1 Mon Sep 17 00:00:00 2001
From: qowevisa <qowevisa@gmail.com>
Date: Fri, 23 Feb 2024 15:28:59 +0200
Subject: [PATCH] Test

---
 .gitignore         |  5 ++++
 Makefile           | 19 +++++++++++++
 README.md          | 13 ++++++++-
 cmd/client/main.go | 47 ++++++++++++++++++++++++++++++
 cmd/server/main.go | 71 ++++++++++++++++++++++++++++++++++++++++++++++
 env/env.go         |  6 ++++
 go.mod             |  3 ++
 7 files changed, 163 insertions(+), 1 deletion(-)
 create mode 100644 Makefile
 create mode 100644 cmd/client/main.go
 create mode 100644 cmd/server/main.go
 create mode 100644 env/env.go
 create mode 100644 go.mod

diff --git a/.gitignore b/.gitignore
index adf8f72..18710ff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,8 @@
 # Go workspace file
 go.work
 
+
+*.pem
+*.key
+*.crt
+bin
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..d6d3c04
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,19 @@
+def: server client
+	@
+
+all: rm def
+	@
+
+rm:
+	rm ./bin/* 2>/dev/null || true
+
+server:
+	go build -o ./bin/$@ ./cmd/$@
+
+client:
+	go build -o ./bin/$@ ./cmd/$@
+
+gen_certs:
+	openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -config san.cnf
+	#openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365
+
diff --git a/README.md b/README.md
index 2e8c34d..abde93b 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,14 @@
 # gotell
 
-simple communication application in golang
\ No newline at end of file
+Simple communication application in golang
+
+## Goals
+
+I want to create as minimalistic communication application in Go as possible.
+
+So in my list contains:
+
+1. Go to stable without use of any third party dependency
+2. Add security to the communication
+3. Implement and test my idea about rotating public-private key pairs
+
diff --git a/cmd/client/main.go b/cmd/client/main.go
new file mode 100644
index 0000000..2901632
--- /dev/null
+++ b/cmd/client/main.go
@@ -0,0 +1,47 @@
+package main
+
+import (
+	"bufio"
+	"crypto/tls"
+	"fmt"
+
+	// "fmt"
+	"io"
+	"log"
+	"os"
+
+	"git.qowevisa.me/Qowevisa/gotell/env"
+)
+
+func main() {
+	cert, err := tls.LoadX509KeyPair("tls.crt", "tls.key")
+	if err != nil {
+		log.Fatalf("server: loadkeys: %s", err)
+	}
+	config := tls.Config{Certificates: []tls.Certificate{cert}}
+	// config.Rand = rand.Reader
+
+	url := fmt.Sprintf("chat.qowevisa.md:%d", env.ConnectPort)
+	// Dial a TLS connection
+	conn, err := tls.Dial("tcp", url, &config)
+	if err != nil {
+		log.Fatalf("Failed to dial: %v", err)
+	}
+	defer conn.Close()
+
+	// Buffer to hold data read from the connection
+	// buf := make([]byte, 1024) // Adjust size as needed
+	reader := bufio.NewScanner(os.Stdin)
+	for reader.Scan() {
+		text := reader.Text()
+		// Read from the connection
+		_, err := conn.Write([]byte(text + "\n"))
+		if err != nil {
+			if err != io.EOF {
+				log.Printf("Read error: %v", err)
+			}
+			break
+		}
+		// fmt.Printf("Received: %s\n", string(buf[:n]))
+	}
+}
diff --git a/cmd/server/main.go b/cmd/server/main.go
new file mode 100644
index 0000000..e49b458
--- /dev/null
+++ b/cmd/server/main.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"bufio"
+	"crypto/rand"
+	"crypto/tls"
+	"fmt"
+	"log"
+	"net"
+	"os"
+
+	"git.qowevisa.me/Qowevisa/gotell/env"
+)
+
+func main() {
+	// Listen on TCP port 8080 on all available unicast and anycast IP addresses of the local system.
+	cert, err := tls.LoadX509KeyPair("tls.crt", "tls.key")
+	if err != nil {
+		log.Fatalf("server: loadkeys: %s", err)
+	}
+	config := tls.Config{Certificates: []tls.Certificate{cert}}
+	config.Rand = rand.Reader
+	url := fmt.Sprintf(":%d", env.Port)
+	listener, err := tls.Listen("tcp", url, &config)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer listener.Close()
+
+	fmt.Println("Server is listening on port 8080")
+
+	for {
+		// Wait for a connection.
+		conn, err := listener.Accept()
+		if err != nil {
+			log.Print(err)
+			continue
+		}
+		// Handle the connection in a new goroutine.
+		// The loop then returns to accepting, so that
+		// multiple connections may be served concurrently.
+		go handleConnection(conn)
+	}
+}
+
+func handleConnection(conn net.Conn) {
+	defer conn.Close()
+
+	fmt.Printf("Client connected: %v\n", conn.RemoteAddr())
+
+	// Create a new reader for each client.
+	scanner := bufio.NewScanner(conn)
+	for scanner.Scan() {
+		// Read the incoming connection into the buffer.
+		text := scanner.Text()
+		fmt.Printf("Received: %s\n", text)
+
+		// Send a response back to client.
+		_, err := conn.Write([]byte("Message received: " + text + "\n"))
+		if err != nil {
+			log.Printf("Failed to write to connection: %v", err)
+			break
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading from connection: %s\n", err)
+	}
+
+	fmt.Printf("Client disconnected: %v\n", conn.RemoteAddr())
+}
diff --git a/env/env.go b/env/env.go
new file mode 100644
index 0000000..2bbfd59
--- /dev/null
+++ b/env/env.go
@@ -0,0 +1,6 @@
+package env
+
+const (
+	Port        = 2993
+	ConnectPort = 1993
+)
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..9cd8f2a
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module git.qowevisa.me/Qowevisa/gotell
+
+go 1.20