wechat_hitxy/main.go

package main

import (
	"crypto/sha1"
	"fmt"
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"
	"sort"
	"strings"
)

func main() {
	if readConfig() != nil {
		log.Fatal("unable to read config, program quit")
		return
	}

	const txt = "P2DoRtilYwJ1aM+VW1sGs6p11Rhcd/TrFYtvsw53SUVw2Knh27hF5IZUBxRXbz+k87zy983ec5aOwgS+WxYoejmGubaqiYy2yfCBNyGRlWfe+iWc2TnvPIEAJebSWuNOJ7FoITeMndr4tW391XxDdMom8I/VsqKnsZZAangUsxmA1ZEnP/d4Lx8/xt3qJKrJMa4Q8s9VsOOvzLIGhL1IN5bHaXN+CwgBTAUCrHD8AneiX5MLSv/74qozg+jKBSUebZrjRYuTymQ3TBh3pQXyRBQTZNrCAe1tlcNli9e5MSUMsHFIzGw/kiu93/5VkxCYRLgRDQKl9oam4+Rpxywir7EiT7I4X343l9ogcMLWX16evkLlQHoqBhLl6ZcfW7Nmq8/Ghy8jbuwqkR/0jLJ/avtjzgJOwaxdBUz4nYZ452rLJekxIvsmV6PZgCXRrKHzmpZX+i6hIRIWiIaDeMOEsw=="
	const msg = `<xml><ToUserName><![CDATA[gh_f09231355c68]]></ToUserName>
<FromUserName><![CDATA[oUN420bxqFqlx0ZQHciUOesZO3PE]]></FromUserName>
<CreateTime>1492972518</CreateTime>
<MsgType><![CDATA[event]]></MsgType>
<Event><![CDATA[CLICK]]></Event>
<EventKey><![CDATA[V1001_TODAY_MUSIC]]></EventKey>
</xml>`
	m := Decode(txt)
	t := Encode(msg)
	fmt.Println(t)
	fmt.Println(m)
	fmt.Println(t == txt)
	fmt.Println(m == msg)

	return
	//setup handler
	http.HandleFunc("/", webrootHandler)
	http.HandleFunc("/api", apiV1Main)

	//http.ListenAndServe("127.0.0.1:65500", nil)
	//CreateDefaultMenu()
	http.ListenAndServe(":65500", nil)
}

//apiV1Main  version 1 main entry for all wechat callbacks
//
func apiV1Main(w http.ResponseWriter, r *http.Request) {
	logRequestDebug(httputil.DumpRequest(r, true))

	switch r.Method {
	case "POST":
		answerWechatPost(w, r)
	case "GET":
		answerInitialAuth(w, r)
	default:
		log.Fatalln("Unhandled HTTP %s", r.Method)
		fmt.Fprintf(w, "Protocol Error: Expect GET or POST only")
	}
}

//
//answerInitialAuth,  when wechat first verify our URL for API hooks
//
func answerInitialAuth(w http.ResponseWriter, r *http.Request) {
	rq := r.URL.RawQuery
	m, _ := url.ParseQuery(rq)

	echostr, eok := m["echostr"]
	if checkSignature(r) && eok {
		fmt.Fprintf(w, echostr[0])
	} else {
		fmt.Fprintf(w, "wtf is wrong with the Internet")
	}
}

//answerWechatPost  distribute PostRequest according to xml body info
//
func answerWechatPost(w http.ResponseWriter, r *http.Request) {
	return
}

//
func checkSignature(r *http.Request) bool {
	rq := r.URL.RawQuery
	m, _ := url.ParseQuery(rq)

	signature, sok := m["signature"]
	timestamp, tok := m["timestamp"]
	nonce, nok := m["nonce"]
	token := APIConfig.Token
	if sok && tok && nok {
		//sort token, timestamp, nonce  and join them
		strs := []string{token, timestamp[0], nonce[0]}
		sort.Strings(strs)
		s := strings.Join(strs, "")

		//calculate sha1
		h := sha1.New()
		h.Write([]byte(s))
		calculated := fmt.Sprintf("%x", h.Sum(nil))
		return signature[0] == calculated
	}
	return false
}

func checkSignature1() bool {
	s1 := "e39de9f2e28079c01ebb4b803dfc3442b819545c"
	t1 := "1492970761"
	n1 := "1850971833"
	token := APIConfig.Token

	strs := []string{token, t1, n1}
	sort.Strings(strs)
	s := strings.Join(strs, "")

	h := sha1.New()
	h.Write([]byte(s))
	us := fmt.Sprintf("%x", h.Sum(nil))
	return s1 == us
}

//webrootHandler sending contents to client when request "/"
//      essentially to prove the webserver is still alive
//      echo query string to the client
func webrootHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
	rq := r.URL.RawQuery
	m, _ := url.ParseQuery(rq)
	for index, element := range m {
		fmt.Fprintf(w, "\r\n%s => %s", index, element)
	}
	logRequestDebug(httputil.DumpRequest(r, true))

}

func logRequestDebug(data []byte, err error) {
	if err == nil {
		fmt.Printf("%s\n\n", data)
	} else {
		log.Fatalf("%s\n\n", err)
	}
}