如何在Go中访问客户的证书？

Below is my code for an HTTPS server in Go. The server requires the client to provide an SSL certificate, but doesn't verify the certificate (by design).

You can generate a private/public key pair as follows if you'd like to give it a try:

$ openssl genrsa -out private.pem 2048
$ openssl req -new -x509 -key private.pem -out public.pem -days 365

Does anyone know how I can access the client certificate in the handler? Let's say I would like to report some properties about the certificate the client presented back to the client.

Thanks, Chris.

package main

import (
    "fmt"
    "crypto/tls"
    "net/http"
)

const (
    PORT       = ":8443"
    PRIV_KEY   = "./private.pem"
    PUBLIC_KEY = "./public.pem"
)

func rootHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprint(w, "Nobody should read this.")
}

func main() {

    server := &http.Server{
        TLSConfig: &tls.Config{
            ClientAuth: tls.RequireAnyClientCert,
            MinVersion: tls.VersionTLS12,
        },
        Addr: "127.0.0.1:8443",
    }

    http.HandleFunc("/", rootHandler)
    err := server.ListenAndServeTLS(PUBLIC_KEY, PRIV_KEY)
    if err != nil {
        fmt.Printf("main(): %s
", err)
    }
}

Seems r *http.Request has TLS *tls.ConnectionState field which in turn has PeerCertificates []*x509.Certificate field, so

fmt.Fprint(w, r.TLS.PeerCertificates)

probably can do