yatwiki/AuthorHash.go

package yatwiki

import (
	"crypto/md5"
	"encoding/hex"
	"net/http"
	"strings"
)

func RemoteAddrToIPAddress(remoteAddr string) string {
	return strings.TrimRight(strings.TrimRight(remoteAddr, `0123456789`), `:`) // trim trailing port; IPv4 and IPv6-safe
}

func Author(r *http.Request, trustXForwardedFor bool) string {
	userAgentHash := md5.Sum([]byte(r.UserAgent()))

	ipAddress := RemoteAddrToIPAddress(r.RemoteAddr)

	if trustXForwardedFor {
		if xff := r.Header.Get("X-Forwarded-For"); len(xff) > 0 {
			ipAddress = xff
		}
	}

	return ipAddress + "-" + hex.EncodeToString(userAgentHash[:])[:6]
}