go语言生成ssl证书

使用https协议时一般需要两个文件，cert.pem和key.pem

cert.pem文件是SSL证书，而key.pem是私钥

可以使用Go标准库中的crypto包群来生成证书与私钥

package main

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"math/big"
	"net"
	"os"
	"time"
)

func main() {
	max := new(big.Int).Lsh(big.NewInt(1), 128)
	serialNumber, _ := rand.Int(rand.Reader, max)
	subject := pkix.Name{
		Organization:       []string{"My Company"},
		OrganizationalUnit: []string{"Person"},
		CommonName:         "example.com",
	}

	template := x509.Certificate{
		SerialNumber: serialNumber,
		Subject:      subject,
		NotBefore:    time.Now(),
		NotAfter:     time.Now().Add(365 * 24 * time.Hour),
		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
		ExtKeyUsage:  [