From 3103affe1fe7dc363dc09831b9deb413c3326f60 Mon Sep 17 00:00:00 2001
From: genshen <genshenchu@gmail.com>
Date: Sun, 9 Jun 2024 21:28:04 +0800
Subject: [PATCH] feat(vpn-qr-code): generate qr code via its content directly,
 instead of requsting qr image

The content of the qr code is a url of `https://sis.ustb.edu.cn/connect/state?sid=${SID}`,
we can generate the qr code via the parsed ${SID}. Then the http request of the qr image
can be omitted.
---
 client-ui/qr_login_ui.go | 14 ++++-------
 go.mod                   |  1 +
 go.sum                   |  2 ++
 plugins/vpn/qr_code.go   | 52 +++++++++++++++++++++++++++++++++++-----
 4 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/client-ui/qr_login_ui.go b/client-ui/qr_login_ui.go
index d4d7d83..fb22eaf 100644
--- a/client-ui/qr_login_ui.go
+++ b/client-ui/qr_login_ui.go
@@ -2,24 +2,18 @@ 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 {
+	if qrImgReader, err := vpn.LoadQrAuthImage(); 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
-		}
+		image := canvas.NewImageFromReader(qrImgReader, "qr.png")
+		image.FillMode = canvas.ImageFillOriginal
+		return image
 	}
 }
diff --git a/go.mod b/go.mod
index 2cbf603..660580a 100644
--- a/go.mod
+++ b/go.mod
@@ -7,6 +7,7 @@ require (
 	github.com/genshen/cmds v0.0.0-20200505065256-d4c52690e15b
 	github.com/genshen/wssocks v0.6.1
 	github.com/sirupsen/logrus v1.9.3
+	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
 	golang.org/x/crypto v0.18.0
 	gopkg.in/yaml.v3 v3.0.1
 )
diff --git a/go.sum b/go.sum
index 2ce2577..a72ef01 100644
--- a/go.sum
+++ b/go.sum
@@ -305,6 +305,8 @@ github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546/go.mod h1:TrYk7fJV
 github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e h1:MRM5ITcdelLK2j1vwZ3Je0FKVCfqOLp5zO6trqMLYs0=
+github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e/go.mod h1:XV66xRDqSt+GTGFMVlhk3ULuV0y9ZmzeVGR4mloJI3M=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/spf13/afero v1.6.0/go.mod h1:Ai8FlHk4v/PARR026UzYexafAt9roJ7LcLMAmO6Z93I=
diff --git a/plugins/vpn/qr_code.go b/plugins/vpn/qr_code.go
index 91a0e07..40aba98 100644
--- a/plugins/vpn/qr_code.go
+++ b/plugins/vpn/qr_code.go
@@ -5,13 +5,16 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"github.com/skip2/go-qrcode"
 	"gopkg.in/yaml.v3"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
 )
 
 const LoadImgUrl = "https://n.ustb.edu.cn/login/"
+const SisAuthPath = "https://sis.ustb.edu.cn"
 const FindQrcodeUrlRegex = `"ustb-qrcode",`
 const FindQrcodeImgTagRegex = `<img`
 
@@ -43,9 +46,16 @@ func (q *QRCodeImgLoaderConfig) genIframeUrl() (string, error) {
 	return fmt.Sprintf("%s?appid=%s&return_url=%s&rand_token=%s&embed_flag=1", q.ApiUrl, q.AppID, q.ReturnUrl, q.RandToken), nil
 }
 
+type QrImg struct {
+	imgUrl string
+	QrImg  []byte
+	Sid    string // sis in ustb auth, can be parsed from image url.
+}
+
 // 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) {
+// and then parse the html file to get final image url (contains SID).
+// And set QrImg's imgUrl and sid.
+func (i *QrImg) ParseQRCodeImgUrl() (string, error) {
 	iframeUrl, err := ParseQRCodeHtmlUrl()
 	if err != nil {
 		return "", err
@@ -64,7 +74,6 @@ func ParseQRCodeImgUrl() (string, error) {
 	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
@@ -73,7 +82,7 @@ func ParseQRCodeImgUrl() (string, error) {
 			if len(subStr) != 5 {
 				return "", errors.New("invalid format in qr image url parsing")
 			} else {
-				imgUrl = subStr[3]
+				i.imgUrl = subStr[3]
 				break
 			}
 		}
@@ -83,8 +92,16 @@ func ParseQRCodeImgUrl() (string, error) {
 		return "", err
 	}
 
+	// parse sid in qr image url.
+	sidStr := strings.SplitN(i.imgUrl, "=", 2)
+	if len(sidStr) != 2 {
+		return "", errors.New("invalid format in qr image url (sis) parsing")
+	} else {
+		i.Sid = sidStr[1]
+	}
+
 	// use htmlUri's host, schema
-	return fmt.Sprintf("%s://%s%s", htmlUri.Scheme, htmlUri.Host, imgUrl), nil
+	return fmt.Sprintf("%s://%s%s", htmlUri.Scheme, htmlUri.Host, i.imgUrl), nil
 }
 
 func ParseQRCodeHtmlUrl() (string, error) {
@@ -140,7 +157,30 @@ func ParseQRCodeHtmlUrl() (string, error) {
 	}
 }
 
-// wait qr state and get auth code
+func (i *QrImg) GenQrImg() error {
+	imgContent := fmt.Sprintf(SisAuthPath+"/auth?sid=%s", i.Sid)
+	qrPng, err := qrcode.Encode(imgContent, qrcode.Medium, 256)
+	if err != nil {
+		return err
+	}
+	i.QrImg = qrPng
+	return nil
+}
+
+func LoadQrAuthImage() (io.Reader, error) {
+	var qr QrImg
+	if _, err := qr.ParseQRCodeImgUrl(); err != nil {
+		return nil, err
+	}
+
+	if err := qr.GenQrImg(); err != nil {
+		return nil, err
+	}
+	buf := bytes.NewReader(qr.QrImg)
+	return buf, nil
+}
+
+// WaitQrState waits qr state and get auth code
 func WaitQrState(imgUrl *url.URL) {
 	// get https://sis.ustb.edu.cn/connect/state?sid=bf1a027b75d6e21b351f81cdc1b739a2
 }