feat(vpn-qr-code): feature of loading QR code image for QR code login

client-ui/main.go

@@ -203,6 +203,15 @@ func main() {
 				{Text: "password", Widget: uiVpnPassword},
 			}},
 		),
+		container.NewTabItemWithIcon(
+			"QR Code",
+			theme.MoreHorizontalIcon(),
+			container.NewVBox(
+				LoadQRImage(),
+				widget.NewLabel("QR code scanned"),
+				widget.NewButton("Load/Reload QR Code", func() {}),
+			),
+		),
 	)
 	tabs.SetTabLocation(container.TabLocationTop)
 	selectCopyProxyCommand := container.NewBorder(nil, nil, nil, nil,

client-ui/qr_login_ui.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/storage"
+	"github.com/genshen/wssocks-plugin-ustb/plugins/vpn"
+	log "github.com/sirupsen/logrus"
+)
+
+// LoadQRImage shows QR image for login
+func LoadQRImage() *canvas.Image {
+	if qrCodeImgUrl, err := vpn.ParseQRCodeImgUrl(); err != nil {
+		log.Println(err) // todo
+		return nil
+	} else {
+		if uri, err := storage.ParseURI(qrCodeImgUrl); err != nil {
+			log.Println(err) // todo:
+			return nil
+		} else {
+			image := canvas.NewImageFromURI(uri)
+			image.FillMode = canvas.ImageFillOriginal
+			return image
+		}
+	}
+}

go.mod

@@ -8,4 +8,5 @@ require (
 	github.com/genshen/wssocks v0.6.1
 	github.com/sirupsen/logrus v1.9.3
 	golang.org/x/crypto v0.18.0
+	gopkg.in/yaml.v3 v3.0.1
 )

plugins/vpn/qr_code.go

@@ -0,0 +1,146 @@
+package vpn
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"gopkg.in/yaml.v3"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+const LoadImgUrl = "https://n.ustb.edu.cn/login/"
+const FindQrcodeUrlRegex = `"ustb-qrcode",`
+const FindQrcodeImgTagRegex = `<img`
+
+// QRCodeImgLoaderConfig is the config to generate an url of sis.ustb.edu.cn for requesting qr code image.
+// here we treat js as yaml (because the source string is not standard json, we can not parse it as a json)
+type QRCodeImgLoaderConfig struct {
+	Id        string `yaml:"id"`
+	ApiUrl    string `yaml:"api_url"`
+	AppID     string `yaml:"appid"`
+	ReturnUrl string `yaml:"return_url"`
+	RandToken string `yaml:"rand_token"`
+}
+
+// GenUrl generates the url of the iframe.
+func (q *QRCodeImgLoaderConfig) GenIframeUrl() (string, error) {
+	if q.ApiUrl == "" {
+		return "", errors.New("api url is empty")
+	}
+	if q.AppID == "" {
+		return "", errors.New("app id is empty")
+	}
+	if q.ReturnUrl == "" {
+		return "", errors.New("return url is empty")
+	}
+	if q.RandToken == "" {
+		return "", errors.New("rand token is empty")
+	}
+	// todo  encodeURI for return_url
+	return fmt.Sprintf("%s?appid=%s&return_url=%s&rand_token=%s&embed_flag=1", q.ApiUrl, q.AppID, q.ReturnUrl, q.RandToken), nil
+}
+
+// ParseQRCodeImgUrl uses ParseQRCodeHtmlUrl to get the iframe html,
+// and then parse the html file to get final image url (contains SID)
+func ParseQRCodeImgUrl() (string, error) {
+	iframeUrl, err := ParseQRCodeHtmlUrl()
+	if err != nil {
+		return "", err
+	}
+	htmlUri, err := url.Parse(iframeUrl)
+	if err != nil {
+		return "", err
+	}
+
+	// make a http request of the iframe
+	response, err := http.Get(iframeUrl)
+	if err != nil {
+		return "", err
+	}
+
+	defer response.Body.Close()
+
+	scanner := bufio.NewScanner(response.Body)
+	imgUrl := ""
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.Contains(line, FindQrcodeImgTagRegex) { // first line to match start
+			// line e.g. <img id="qrimg" src="/connect/qrimg?sid=3894c5568dd1ef0f6434f426297a678d" height="90%" border="0">
+			subStr := strings.SplitN(line, "\"", 5)
+			if len(subStr) != 5 {
+				return "", errors.New("invalid format in qr image url parsing")
+			} else {
+				imgUrl = subStr[3]
+				break
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	// use htmlUri's host, schema
+	return fmt.Sprintf("%s://%s%s", htmlUri.Scheme, htmlUri.Host, imgUrl), nil
+}
+
+func ParseQRCodeHtmlUrl() (string, error) {
+	// parse the html of `LOAD_IMG_URL` to get following object text:
+	//{
+	//  id: "ustb-qrcode",
+	//	api_url: "",
+	//	appid: "",
+	//	return_url: "",
+	//	rand_token: "",
+	//	width: "",
+	//	height: ""
+	//}
+	response, err := http.Get(LoadImgUrl)
+	if err != nil {
+	}
+
+	defer response.Body.Close()
+
+	scanner := bufio.NewScanner(response.Body)
+	var findQrMatchStart = false
+	var qrConfigBuffer bytes.Buffer
+	qrConfigBuffer.WriteString("{")
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.Contains(line, FindQrcodeUrlRegex) { // first line to match start
+			findQrMatchStart = true // start match
+		}
+		// only start matched and end not matched, we can add text to buffer.
+		if findQrMatchStart {
+			qrConfigBuffer.WriteString(line)
+			if strings.Contains(line, "}") {
+				break
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	fmt.Println("parsed qr code config:", qrConfigBuffer.String())
+	var qrImgUrlConfig QRCodeImgLoaderConfig
+	if err := yaml.Unmarshal(qrConfigBuffer.Bytes(), &qrImgUrlConfig); err != nil {
+		return "", err
+	}
+
+	// generate iframe url.
+	if qrUrl, err := qrImgUrlConfig.GenIframeUrl(); err != nil {
+		return "", err
+	} else {
+		return qrUrl, nil
+	}
+}
+
+// wait qr state and get auth code
+func WaitQrState(imgUrl *url.URL) {
+	// get https://sis.ustb.edu.cn/connect/state?sid=bf1a027b75d6e21b351f81cdc1b739a2
+}

plugins/vpn/qr_code_test.go

@@ -0,0 +1,22 @@
+package vpn
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestQRCodeHtmlUrl(t *testing.T) {
+	u, err := ParseQRCodeHtmlUrl()
+	if err != nil {
+		t.Error("error in loading qr code html url:", err)
+	}
+	fmt.Println(u)
+}
+
+func TestQRCodeImgUrl(t *testing.T) {
+	u, err := ParseQRCodeImgUrl()
+	if err != nil {
+		t.Error("error in loading qr code img url:", err)
+	}
+	fmt.Println(u)
+}