generate cert pem and key pem

main.go

package main

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"fmt"
	"log"
	"math/big"
	"time"
)

func main() {
	key, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		log.Fatal("Private key cannot be created.", err.Error())
	}

	// Generate a pem block with the private key
	keyPem := pem.EncodeToMemory(&pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(key),
	})

	tml := x509.Certificate{
		// you can add any attr that you need
		NotBefore: time.Now(),
		NotAfter:  time.Now().AddDate(5, 0, 0),
		// you have to generate a different serial number each execution
		SerialNumber: big.NewInt(123123),
		Subject: pkix.Name{
			CommonName:   "New Name",
			Organization: []string{"New Org."},
		},
		BasicConstraintsValid: true,
	}
	cert, err := x509.CreateCertificate(rand.Reader, &tml, &tml, &key.PublicKey, key)
	if err != nil {
		log.Fatal("Certificate cannot be created.", err.Error())
	}

	// Generate a pem block with the certificate
	certPem := pem.EncodeToMemory(&pem.Block{
		Type:  "CERTIFICATE",
		Bytes: cert,
	})

	fmt.Println("keyPen", string(keyPem))
	fmt.Println("certPem", string(certPem))
}