SSL エラーが発生した場合に Golang で HTTPS 証明書を検証する方法

package main

import (
    "crypto/tls"
    "io/ioutil"
    "log"
    "net/http"
    "crypto/x509"
)

func main() {
    // Read the root CA certificate from file
    caCert, err := ioutil.ReadFile("rootCA.crt")
    if err != nil {
        log.Fatal(err)
    }

    // Create an X.509 certificate pool and add the CA certificate
    caCertPool := x509.NewCertPool()
    caCertPool.AppendCertsFromPEM(caCert)

    // Configure the TLS client to trust the CA
    tlsConfig := &tls.Config{
        RootCAs: caCertPool,
    }

    // Create a new HTTP client with the modified TLS configuration
    client := &http.Client{
        Transport: &http.Transport{
            TLSClientConfig: tlsConfig,
        },
    }

    // Make an HTTPS request using the client
    _, err = client.Get("https://secure.domain.com")
    if err != nil {
        panic(err)
    }
}

openssl genrsa -out rootCA.key 4096
openssl req -x509 -new -key rootCA.key -days 3650 -out rootCA.crt

openssl genrsa -out secure.domain.com.key 2048
openssl req -new -key secure.domain.com.key -out secure.domain.com.csr
#In answer to question `Common Name (e.g. server FQDN or YOUR name) []:` you should set `secure.domain.com` (your real domain name)
openssl x509 -req -in secure.domain.com.csr -CA rootCA.crt -CAkey rootCA.key -CAcreateserial -days 365 -out secure.domain.com.crt