ssl-checker.go

package main

import (
	"crypto/tls"
	"log"
	"fmt"
	"os"
	"time"
)

func main() {

	if len(os.Args) != 2 {
		log.Fatal("Addres is required")
	}

	addr := os.Args[1]

	conn, err := tls.Dial("tcp", addr, &tls.Config{
		InsecureSkipVerify: false,
	})

	if err!=nil {
		log.Fatal(err)
	}

	ceritificates := conn.ConnectionState().PeerCertificates;

	for _, cert := range ceritificates {
		//str, _ := json.MarshalIndent(cert, "", " ")
		now := time.Now()
		expire := cert.NotAfter.Sub(now).Hours()

		fmt.Printf("Subject: %s\n", cert.Subject.CommonName)
		fmt.Printf("Issuer: %s\n", cert.Issuer.CommonName)
		fmt.Printf("NotBefore: %s\n", cert.NotBefore)
		fmt.Printf("NotAfter: %s\n", cert.NotAfter)
		if expire > 24 {
			fmt.Printf("Expire in: %v days\n", int(expire/24+0.5))
		} else if (expire > 0) {
			fmt.Printf("Expire in: %v hours\n", int(expire+0.5))
		} else {
			fmt.Println("Expired!")
		}

		fmt.Println()
	}

	conn.Close();
}