Give serial to the device during cert exchange so it can provide it whenever it connects

Summary:
Android devices don't always know their own serial.
But we do a certificate exchange using adb from the desktop, so we can provide it in the response.

After this the client will provide it every time it connects, so we can do things like filter plugins by device id.

For apps that have already done cert exchange, they'll continue to use 'unknown' as their id until they do it again with an up to date version of sonar.
We can think about forcefully stopping that, but I haven't done it.

Reviewed By: danielbuechele

Differential Revision: D9481460

fbshipit-source-id: f8932699711ebbec4260fabe32f87e6cdff920f2

xplat/Sonar/SonarWebSocketImpl.cpp

@@ -35,6 +35,7 @@
 #define SONAR_CA_FILE_NAME "sonarCA.crt"
 #define CLIENT_CERT_FILE_NAME "device.crt"
 #define PRIVATE_KEY_FILE "privateKey.pem"
+#define CONNECTION_CONFIG_FILE "connection_config.json"
 #define WRONG_THREAD_EXIT_MSG \
   "ERROR: Aborting sonar initialization because it's not running in the sonar thread."
 
@@ -47,6 +48,7 @@ namespace facebook {
 namespace sonar {
 
 bool fileExists(std::string fileName);
+void writeStringToFile(std::string content, std::string fileName);
 
 class ConnectionEvents : public rsocket::RSocketConnectionEvents {
  private:
@@ -176,9 +178,12 @@ void SonarWebSocketImpl::doCertificateExchange() {
 void SonarWebSocketImpl::connectSecurely() {
   rsocket::SetupParameters parameters;
   folly::SocketAddress address;
+
+  auto deviceId = getDeviceId();
+
   parameters.payload = rsocket::Payload(folly::toJson(folly::dynamic::object(
       "os", deviceData_.os)("device", deviceData_.device)(
-      "device_id", deviceData_.deviceId)("app", deviceData_.app)));
+      "device_id", deviceId)("app", deviceData_.app)));
   address.setFromHostPort(deviceData_.host, securePort);
 
   std::shared_ptr<folly::SSLContext> sslContext =
@@ -242,6 +247,27 @@ void SonarWebSocketImpl::sendMessage(const folly::dynamic& message) {
   });
 }
 
+std::string SonarWebSocketImpl::getDeviceId() {
+  /* On android we can't reliably get the serial of the current device
+     So rely on our locally written config, which is provided by the
+     desktop app.
+     For backwards compatibility, when this isn't present, fall back to the
+     unreliable source. */
+  auto gettingDeviceId = sonarState_->start("Get deviceId");
+  std::string config = loadStringFromFile(absoluteFilePath(CONNECTION_CONFIG_FILE));
+  auto maybeDeviceId = folly::parseJson(config)["deviceId"];
+  std::string deviceId;
+  if (maybeDeviceId.isString()) {
+    deviceId = maybeDeviceId.getString();
+  } else {
+    deviceId = deviceData_.deviceId;
+  }
+  if (deviceId.compare("unknown")) {
+    gettingDeviceId->complete();
+  }
+  return deviceId;
+}
+
 bool SonarWebSocketImpl::isCertificateExchangeNeeded() {
 
   if (failedConnectionAttempts_ >= 2) {
@@ -281,6 +307,8 @@ void SonarWebSocketImpl::requestSignedCertFromSonar() {
     client_->getRequester()
         ->requestResponse(rsocket::Payload(folly::toJson(message)))
         ->subscribe([this, gettingCert](rsocket::Payload p) {
+          auto response = p.moveDataToString();
+          writeStringToFile(response, absoluteFilePath(CONNECTION_CONFIG_FILE));
           gettingCert->complete();
           SONAR_LOG("Certificate exchange complete.");
           // Disconnect after message sending is complete.
@@ -338,6 +366,11 @@ std::string SonarWebSocketImpl::loadStringFromFile(std::string fileName) {
   return s;
 }
 
+void writeStringToFile(std::string content, std::string fileName) {
+  std::ofstream out(fileName);
+  out << content;
+}
+
 std::string SonarWebSocketImpl::absoluteFilePath(const char* filename) {
   return std::string(deviceData_.privateAppDirectory + "/sonar/" + filename);
 }

xplat/Sonar/SonarWebSocketImpl.h

@@ -66,6 +66,7 @@ class SonarWebSocketImpl : public SonarWebSocket {
   bool ensureSonarDirExists();
   bool isRunningInOwnThread();
   void sendLegacyCertificateRequest(folly::dynamic message);
+  std::string getDeviceId();
 };
 
 } // namespace sonar