knet.go

package knet

import (
	"github.com/PuerkitoBio/goquery"
	"golang.org/x/net/publicsuffix"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"strings"
	"time"
)

const NetworkError = "Network Error"

func IsInternetAvailable() bool {
	res, err := http.Get("http://detectportal.firefox.com/success.txt")
	if err != nil {
		return false
	}
	defer res.Body.Close()
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		log.Fatal(err)
	}
	result := string(body)
	if strings.Contains(result, "success") {
		return true
	}
	return false
}

func Login(uid string, pass string) error {
	var (
		res *http.Response
		doc *goquery.Document
		err error
	)

	jar, err := cookiejar.New(&cookiejar.Options{PublicSuffixList: publicsuffix.List})
	if err != nil {
		return err
	}

	client := &http.Client{
		Transport: &http.Transport{
			DialContext: (&net.Dialer{
				Timeout:   30 * time.Second,
				KeepAlive: 30 * time.Second,
				DualStack: true,
			}).DialContext,
			MaxIdleConns:          100,
			IdleConnTimeout:       90 * time.Second,
			TLSHandshakeTimeout:   10 * time.Second,
			ExpectContinueTimeout: 1 * time.Second,
		},
		Jar: jar,
	}

	res, err = client.Get("https://netauth.cis.kit.ac.jp/auth/login.php")
	if err != nil {
		return err
	}

	postURL := res.Request.URL.String()

	/* id password -> SAML	*/
	payload := url.Values{}
	payload.Add("j_username", uid)
	payload.Add("j_password", pass)
	payload.Add("_eventId_proceed", "")
	res, err = client.PostForm(postURL, payload)
	if err != nil {
		return err
	}

	/* SAMLの解析 */
	doc, _ = goquery.NewDocumentFromResponse(res)
	postURL, payload, err = formParser(doc.Find("form"))
	if err != nil {
		return err
	}
	//log.Println(doc.Text())
	//log.Println(postURL)

	/* SAML -> login.php uid pwd */
	res, err = client.PostForm(postURL, payload)
	if err != nil {
		return err
	}

	doc, _ = goquery.NewDocumentFromResponse(res)
	postURL, payload, err = formParser(doc.Find("form"))
	if err != nil {
		return err
	}
	//log.Println(doc.Text())
	//log.Println(postURL)
	//log.Println(payload)

	res, err = client.PostForm(postURL, payload)
	if err != nil {
		return err
	}

	doc, _ = goquery.NewDocumentFromResponse(res)
	//log.Println(doc.Text())
	return nil
}

type FormParseError struct {
	Message string
}

func (e *FormParseError) Error() string {
	return e.Message
}

func formParser(form *goquery.Selection) (string, url.Values, error) {
	postURL, e := form.Attr("action")
	if !e {
		return "", nil, &FormParseError{"action Attribute not found"}
	}
	data := url.Values{}
	form.Find("input").Each(func(_ int, input *goquery.Selection) {
		name, en  := input.Attr("name")
		value, ev := input.Attr("value")
		if !en || !ev {
			return
		}
		data.Add(name, value)
	})
	return postURL, data, nil
}