OpenVAS Go TLS证书错误

Question

I'm currently developing a custom scanner in go for OpenVAS. Problem is that the handshake with my custom server fails.

I traced the problem down to error -73: GNUTLS_E_ASN1_TAG_ERROR from gnutls_handshake, but I can't find any resources on that problem. I read something about the certificates being incorrect then but I can't do anything other than regenerating the OpenVAS certificates. The tls functionality in the go server just uses a simple ListenAndServeTLS and gets the server cert and key.

edit: So this is the relevant network part on the custom scanner:

var (
    port = ":1234"
    cert = "/usr/local/var/lib/openvas/CA/servercert.pem"
    ca   = "/usr/local/var/lib/openvas/CA/cacert.pem"
    key  = "/usr/local/var/lib/openvas/private/CA/serverkey.pem"
)

    func start_server() {

    ca_file, err := ioutil.ReadFile(ca)

    if err != nil {
        panic(err)
    }

    blocks, _ := pem.Decode( ca_file )
    ca, err := x509.ParseCertificate(blocks.Bytes)

    if err != nil {
        panic(err)
    }

    priv_file, _ := ioutil.ReadFile(key)
    blocks2, _ := pem.Decode( priv_file )

    priv, err := x509.ParsePKCS1PrivateKey(blocks2.Bytes)

    if err != nil {
        panic(err)
    }

    pool := x509.NewCertPool()
    pool.AddCert(ca)

    cert := tls.Certificate{
        Certificate: [][]byte{ca_file},
        PrivateKey:  priv,
    }

    config := tls.Config{
        ClientAuth:   tls.RequireAndVerifyClientCert,
        Certificates: []tls.Certificate{cert},
        ClientCAs:    pool,
    }
    config.Rand = rand.Reader
    service := "0.0.0.0" + port
    listener, err := tls.Listen("tcp", service, &config)

    if err != nil {
        log.Fatalf("server: listen: %s", err)
    }
    log.Print("server: listening")

    for {
        conn, err := listener.Accept()
        if err != nil {
            log.Printf("server: accept: %s", err)
            break
        }

        defer conn.Close()
        log.Printf("server: accepted from %s", conn.RemoteAddr())
        go handle(conn)
    }
}

func handle(conn net.Conn) {

str := "Hello"

defer conn.Close()

buf := make([]byte, 512)
for {
    log.Print("server: conn: waiting")
    conn.Write( ([]byte)(str) )
    n, err := conn.Read(buf)
    if err != nil {
        if err != nil {
            fmt.Println (err)
        }
        break
    }

    tlscon, ok := conn.(*tls.Conn)
    if ok {
        state := tlscon.ConnectionState()
        sub := state.PeerCertificates[0].Subject
        log.Println(sub)
    }

    log.Printf("server: conn: echo %q
", string(buf[:n]))
    n, err = conn.Write(buf[:n])

    n, err = conn.Write(buf[:n])
    log.Printf("server: conn: wrote %d bytes", n)

    if err != nil {
        log.Printf("server: write: %s", err)
        break
    }
}
log.Println("server: conn: closed")

}

func main() {

start_server()

}

It's taken from an example but it didn't work properly at first ( there was no decode before parsecertificates). Maybe the certificate is mal-formatted now because of that? Before adding the two decodes I had a similar error about the asn1 tags not matching. So also an asn1 error. I thought of generating my own certificate but I don't know if this will not break OpenVAS for the other scanners. I had the same results when just using listenandservetls from go. The error is definitely produced in gnutls_handshake. It's frustrating that I only get an error code from that.