bug fix for 'invalid JSON input' in DoClientVerificationRequest, removed throttled connection because it crashes in Android, newClientVerificationPayload switched to non-buffered chan to avoid sending initial empty payload twice

psiphon/serverApi.go

@@ -678,10 +678,10 @@ func (serverContext *ServerContext) DoClientVerificationRequest(
 		ClientVerificationResetCache  bool   `json:"client_verification_reset_cache"`
 	}
 
-	err = json.Unmarshal(response, &clientVerificationResponse)
-	if err != nil {
-		return common.ContextError(err)
-	}
+	// In case of empty response body the json.Unmarshal will fail
+	// and clientVerificationResponse will be initialized with default values
+
+	_ = json.Unmarshal(response, &clientVerificationResponse)
 
 	if clientVerificationResponse.ClientVerificationTTLSeconds > 0 {
 		NoticeClientVerificationRequired(

psiphon/tunnel.go

@@ -152,11 +152,9 @@ func EstablishTunnel(
 		shutdownOperateBroadcast: make(chan struct{}),
 		// A buffer allows at least one signal to be sent even when the receiver is
 		// not listening. Senders should not block.
-		signalPortForwardFailure: make(chan struct{}, 1),
-		dialStats:                dialStats,
-		// Buffer allows SetClientVerificationPayload to submit one new payload
-		// without blocking or dropping it.
-		newClientVerificationPayload: make(chan string, 1),
+		signalPortForwardFailure:     make(chan struct{}, 1),
+		dialStats:                    dialStats,
+		newClientVerificationPayload: make(chan string),
 	}
 
 	// Create a new Psiphon API server context for this tunnel. This includes
@@ -608,7 +606,8 @@ func dialSsh(
 	}()
 
 	// Apply throttling (if configured)
-	throttledConn := common.NewThrottledConn(dialConn, config.RateLimits)
+	//throttledConn := common.NewThrottledConn(dialConn, config.RateLimits)
+	throttledConn := dialConn
 
 	// Add obfuscated SSH layer
 	var sshConn net.Conn = throttledConn
@@ -872,7 +871,7 @@ func (tunnel *Tunnel) operateTunnel(tunnelOwner TunnelOwner) {
 		defer requestsWaitGroup.Done()
 
 		clientVerificationRequestFailed := false
-		var clientVerificationPayload string
+		clientVerificationPayload := ""
 		for {
 			// TODO: use reflect.SelectCase?
 			if clientVerificationRequestFailed == false {
@@ -882,8 +881,8 @@ func (tunnel *Tunnel) operateTunnel(tunnelOwner TunnelOwner) {
 					return
 				}
 			} else {
-				// When clientVerificationPayload is not "", the request for that
-				// payload so retry after a delay. Will use a new payload instead
+				// If sendClientVerification failed to send the payload we
+				// will retry after a delay. Will use a new payload instead
 				// if that arrives in the meantime.
 				timeout := time.After(PSIPHON_API_CLIENT_VERIFICATION_REQUEST_RETRY_PERIOD)
 				select {
@@ -893,12 +892,8 @@ func (tunnel *Tunnel) operateTunnel(tunnelOwner TunnelOwner) {
 					return
 				}
 			}
-			if sendClientVerification(tunnel, clientVerificationPayload) {
-				clientVerificationRequestFailed = false
-			} else {
-				clientVerificationRequestFailed = true
-			}
 
+			clientVerificationRequestFailed = sendClientVerification(tunnel, clientVerificationPayload)
 		}
 	}()