chore: simplify random state generation

cmd/token_tronity.go

@@ -2,11 +2,8 @@ package cmd
 
 import (
 	"context"
-	"crypto/rand"
-	"encoding/base64"
 	"errors"
 	"fmt"
-	"io"
 	"net/http"
 	"strings"
 	"sync"
@@ -16,19 +13,11 @@ import (
 	"github.com/evcc-io/evcc/util"
 	"github.com/evcc-io/evcc/vehicle"
 	"github.com/evcc-io/evcc/vehicle/tronity"
+	"github.com/samber/lo"
 	"github.com/skratchdot/open-golang/open"
 	"golang.org/x/oauth2"
 )
 
-// github.com/uhthomas/tesla
-func state() string {
-	var b [9]byte
-	if _, err := io.ReadFull(rand.Reader, b[:]); err != nil {
-		panic(err)
-	}
-	return base64.RawURLEncoding.EncodeToString(b[:])
-}
-
 func tokenExchangeHandler(oc *oauth2.Config, state string, resC chan *oauth2.Token) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if remote := r.URL.Query().Get("state"); state != remote {
@@ -57,7 +46,7 @@ func tokenExchangeHandler(oc *oauth2.Config, state string, resC chan *oauth2.Tok
 }
 
 func tronityAuthorize(addr string, oc *oauth2.Config) (*oauth2.Token, error) {
-	state := state()
+	state := lo.RandomString(16, lo.AlphanumericCharset)
 
 	uri := oc.AuthCodeURL(state, oauth2.AccessTypeOffline)
 	uri = strings.ReplaceAll(uri, "scope=", "scopes=")

vehicle/ford/identity.go

@@ -15,6 +15,7 @@ import (
 	"github.com/evcc-io/evcc/util/oauth"
 	"github.com/evcc-io/evcc/util/request"
 	cv "github.com/nirasan/go-oauth-pkce-code-verifier"
+	"github.com/samber/lo"
 	"golang.org/x/oauth2"
 )
 
@@ -66,7 +67,8 @@ func (v *Identity) login() (*oauth.Token, error) {
 		return nil, err
 	}
 
-	uri := OAuth2Config.AuthCodeURL("",
+	state := lo.RandomString(16, lo.AlphanumericCharset)
+	uri := OAuth2Config.AuthCodeURL(state,
 		oauth2.SetAuthURLParam("max_age", "3600"),
 		oauth2.SetAuthURLParam("code_challenge", cv.CodeChallengeS256()),
 		oauth2.SetAuthURLParam("code_challenge_method", "S256"),