bump snap version

Improve chrome web store XML parsing

extver.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"context"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+var (
+	defaultProdVersion = "113.0"
+)
+
+var (
+	ErrNoVerData = errors.New("no version data returned")
+)
+
+type StoreExtUpdateResponse struct {
+	XMLName xml.Name `xml:"gupdate"`
+	App     *struct {
+		AppID       string `xml:"appid,attr"`
+		Status      string `xml:"status,attr"`
+		UpdateCheck *struct {
+			Version string `xml:"version,attr"`
+			Status  string `xml:"status,attr"`
+		} `xml:"updatecheck"`
+	} `xml:"app"`
+}
+
+func GetExtVer(ctx context.Context,
+	prodVersion *string,
+	id string,
+	dialer ContextDialer,
+) (string, error) {
+	if prodVersion == nil {
+		prodVersion = &defaultProdVersion
+	}
+	if dialer == nil {
+		dialer = &net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}
+	}
+
+	transport := &http.Transport{
+		DialContext:           dialer.DialContext,
+		ForceAttemptHTTP2:     true,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+	defer transport.CloseIdleConnections()
+	httpClient := &http.Client{
+		Transport: transport,
+	}
+
+	reqURL := (&url.URL{
+		Scheme: "https",
+		Host:   "clients2.google.com",
+		Path:   "/service/update2/crx",
+		RawQuery: url.Values{
+			"prodversion":  {*prodVersion},
+			"acceptformat": {"crx2,crx3"},
+			"x": {url.Values{
+				"id": {id},
+				"uc": {""},
+			}.Encode()},
+		}.Encode(),
+	}).String()
+
+	req, err := http.NewRequestWithContext(ctx, "GET", reqURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("chrome web store request construction failed: %w", err)
+	}
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("chrome web store request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("bad status code: %d", resp.StatusCode)
+	}
+
+	reader := io.LimitReader(resp.Body, 64*1024)
+	var respData *StoreExtUpdateResponse
+
+	dec := xml.NewDecoder(reader)
+	err = dec.Decode(&respData)
+	if err != nil {
+		return "", fmt.Errorf("unmarshaling of chrome web store response failed: %w", err)
+	}
+
+	if respData != nil && respData.App != nil &&
+		respData.App.UpdateCheck != nil && respData.App.UpdateCheck.Version != "" {
+		return respData.App.UpdateCheck.Version, nil
+	}
+
+	return "", ErrNoVerData
+}

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"crypto/tls"
 	"crypto/x509"
 	"errors"
@@ -17,6 +18,10 @@ import (
 	xproxy "golang.org/x/net/proxy"
 )
 
+const (
+	HolaExtStoreID = "gkojfkhlekighikafcpjkiklfbnlmeio"
+)
+
 var (
 	PROTOCOL_WHITELIST map[string]bool
 	version            = "undefined"
@@ -63,7 +68,7 @@ type CLIArgs struct {
 
 func parse_args() CLIArgs {
 	var args CLIArgs
-	flag.StringVar(&args.extVer, "ext-ver", "999.999.999", "extension version to mimic in requests. "+
+	flag.StringVar(&args.extVer, "ext-ver", "", "extension version to mimic in requests. "+
 		"Can be obtained from https://chrome.google.com/webstore/detail/hola-vpn-the-website-unbl/gkojfkhlekighikafcpjkiklfbnlmeio")
 	flag.StringVar(&args.force_port_field, "force-port-field", "", "force specific port field/num (example 24232 or lum)") // would be nice to not show in help page
 	flag.StringVar(&args.country, "country", "us", "desired proxy location")
@@ -173,6 +178,18 @@ func run() int {
 		return print_countries(args.timeout)
 	}
 
+	if args.extVer == "" {
+		ctx, cl := context.WithTimeout(context.Background(), args.timeout)
+		defer cl()
+		extVer, err := GetExtVer(ctx, nil, HolaExtStoreID, dialer)
+		if err != nil {
+			mainLogger.Critical("Can't detect latest API version. Try to specify -ext-ver parameter. Error: %v", err)
+			return 8
+		}
+		args.extVer = extVer
+		mainLogger.Warning("Detected latest extension version: %q. Pass -ext-ver parameter to skip resolve and speedup startup", args.extVer)
+		cl()
+	}
 	if args.list_proxies {
 		return print_proxies(mainLogger, args.extVer, args.country, args.proxy_type, args.limit, args.timeout,
 			args.backoffInitial, args.backoffDeadline)

snapcraft.yaml

@@ -1,5 +1,5 @@
 name: hola-proxy
-version: '1.8.0'
+version: '1.9.1'
 summary: Standalone Hola proxy client.
 description: |
   Standalone Hola proxy client. Just run it and it'll start plain HTTP proxy server forwarding traffic via Hola proxies of your choice.