Check Chrome Stable Update

go.mod

module github.com/ayanamist/CheckChrome

require github.com/google/uuid v1.2.0

go.sum

github.com/google/uuid v1.2.0 h1:qJYtXnJRWmpe7m/3XlyhrsLrEURqHRM2kxzoxXqyUDs=
github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

main.go

package main

import (
	"encoding/xml"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"strings"
	"sync"
	"time"

	"github.com/google/uuid"
)

const (
	updateUrl = "https://tools.google.com/service/update2"

	archX86 = "x86"
	archX64 = "x64"

	channelStableX86 = "-multi-chrome"
	channelStableX64 = "x64-stable-multi-chrome"
	channelBetaX86   = "1.1-beta"
	channelBetaX64   = "x64-beta-multi-chrome"
	channelDevX86    = "2.0-dev"
	channelDevX64    = "x64-dev-multi-chrome"
	channelCanaryX86 = "" // not a mistake, yes, it's blank
	channelCanaryX64 = "x64-canary"

	postBodyTemplate = `<?xml version='1.0' encoding='UTF-8'?>
	<request protocol='3.0' version='1.3.23.9' shell_version='1.3.21.103' ismachine='0'
			 sessionid='%s' installsource='ondemandcheckforupdate'
			 requestid='%s' dedup='cr'>
	<hw sse='1' sse2='1' sse3='1' ssse3='1' sse41='1' sse42='1' avx='1' physmemory='12582912' />
	<os platform='win' version='6.3' arch='%s'/>
	<app appid='{8A69D345-D564-463C-AFF1-A69D9E530F96}' ap='%s' version='' nextversion='' lang='' brand='GGLS' client=''>
		<updatecheck/>
	</app>
	</request>`
)

var (
	httpClient = &http.Client{
		Transport: &http.Transport{
			DialContext: (&net.Dialer{
				Timeout: 10 * time.Second,
			}).DialContext,
			ResponseHeaderTimeout: 10 * time.Second,
		},
		Timeout: 30 * time.Second,
	}
)

type Response struct {
	Urls []struct {
		Codebase string `xml:"codebase,attr"`
	} `xml:"app>updatecheck>urls>url"`
	Manifest struct {
		Version string `xml:"version,attr"`
		Package struct {
			HashSha256 string `xml:"hash_sha256,attr"`
			Name       string `xml:"name,attr"`
			Size       string `xml:"size,attr"`
		} `xml:"packages>package"`
	} `xml:"app>updatecheck>manifest"`
}

type args struct {
	friendlyName string
	arch         string
	channel      string
}

func httpPost(url string, body string) ([]byte, error) {
	req, err := http.NewRequest(http.MethodPost, url, strings.NewReader(body))
	if err != nil {
		return nil, err
	}
	resp, err := httpClient.Do(req)
	if err != nil {
		return nil, err
	}
	respBody, err := ioutil.ReadAll(resp.Body)
	io.Copy(ioutil.Discard, resp.Body)
	resp.Body.Close()
	return respBody, err
}

func main() {
	args := []args{
		{"X86 Stable", archX86, channelStableX86},
		{"X64 Stable", archX64, channelStableX64},
	}
	wg := sync.WaitGroup{}
	wg.Add(len(args))
	for _, v := range args {
		a := v
		go func() {
			defer wg.Done()
			resp, err := httpPost(updateUrl, fmt.Sprintf(postBodyTemplate, uuid.NewString(), uuid.NewString(), a.arch, a.channel))
			if err != nil {
				log.Printf("%+v post error: %v", a, err)
				return
			}
			var result Response
			if err := xml.Unmarshal(resp, &result); err != nil {
				log.Printf("%+v unmarshal error: %v\n%s", a, err, resp)
				return
			}
			var downloadUrl string
			pkg := result.Manifest.Package
			codebaseUrls := result.Urls
			for _, c := range codebaseUrls {
				s := c.Codebase
				if strings.Contains(s, "https://dl.google.com/") {
					downloadUrl = s + pkg.Name
					break
				}
			}
			if downloadUrl == "" && len(codebaseUrls) > 0 {
				downloadUrl = codebaseUrls[0].Codebase + pkg.Name
			}
			fmt.Printf("%s updates:\nVersion: %s\nDownload: %s\nSHA256: %s\nSize: %s\n\n",
				a.friendlyName, result.Manifest.Version, downloadUrl, pkg.HashSha256, pkg.Size)
		}()
	}
	wg.Wait()
}