fproxy/main.go

128 lines
2.8 KiB
Go

package main
import (
"crypto/tls"
"crypto/x509"
"flag"
"fmt"
"io/ioutil"
"local1/logger"
"net/http"
"net/http/httputil"
"net/url"
"os"
"strings"
)
type Server struct {
addr string
transport *http.Transport
}
func NewServer(addr, clientcrt, clientkey, servercrt string) (*Server, error) {
caCert, err := ioutil.ReadFile(servercrt)
if err != nil {
return nil, err
}
rootCAs := x509.NewCertPool()
rootCAs.AppendCertsFromPEM(caCert)
clientCert, err := tls.LoadX509KeyPair(clientcrt, clientkey)
if err != nil {
return nil, err
}
return &Server{
addr: addr,
transport: &http.Transport{
Proxy: func(*http.Request) (*url.URL, error) {
return url.Parse(addr)
},
TLSClientConfig: &tls.Config{
RootCAs: rootCAs,
Certificates: []tls.Certificate{clientCert},
},
},
}, nil
}
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// fix scheme if necessary
fixScheme(r.URL)
// if not from localhost
if !fromLocalhost(r.RemoteAddr) {
denyAccess(w)
return
}
// proxy via stuncaddsies
proxy := httputil.NewSingleHostReverseProxy(pathlessURL(r.URL))
proxy.Transport = s.transport
proxy.ServeHTTP(w, r)
return
}
func fixScheme(u *url.URL) {
if u.Scheme == "" {
u.Scheme = "http"
if strings.Contains(u.Host, "443") {
u.Scheme = "https"
}
}
}
func fromLocalhost(addr string) bool {
return strings.Contains(addr, "[::1]") || addr == "127.0.0.1" || addr == "::1"
}
func denyAccess(w http.ResponseWriter) {
w.WriteHeader(http.StatusUnauthorized)
fmt.Fprintln(w, "You shouldn't be here")
}
func pathlessURL(u *url.URL) *url.URL {
return &url.URL{
Scheme: u.Scheme,
Opaque: u.Opaque,
User: u.User,
Host: u.Host,
Path: "",
RawPath: "",
ForceQuery: u.ForceQuery,
RawQuery: u.RawQuery,
Fragment: u.Fragment,
}
}
func flagEnvFallback(keyFallback map[string]string) map[string]string {
results := map[string]*string{}
for k, v := range keyFallback {
results[k] = flag.String(k, v, "")
}
flag.Parse()
final := map[string]string{}
for k := range results {
if *results[k] == keyFallback[k] && os.Getenv(strings.ToUpper(k)) != "" {
*results[k] = os.Getenv(strings.ToUpper(k))
}
final[k] = *results[k]
}
return final
}
func main() {
conf := flagEnvFallback(map[string]string{
"stunaddr": "https://localhost:20018",
"clientcrt": "../../stuncaddsies/mnt/stunclient.crt",
"clientkey": "../../stuncaddsies/mnt/stunclient.key",
"servercrt": "../../stuncaddsies/mnt/stunserver.crt",
"port": "8888",
})
if !strings.HasPrefix(conf["port"], ":") {
conf["port"] = ":" + conf["port"]
}
logger.Log(conf)
server, err := NewServer(conf["stunaddr"], conf["clientcrt"], conf["clientkey"], conf["servercrt"])
if err != nil {
logger.Fatal(err)
}
logger.Fatal(http.ListenAndServe(conf["port"], server))
}