Extract file system interaction from SonarWebSocketImpl

Summary:
SonarWebSocketImpl has got pretty bloated. So I'm extracting all the file interaction out of it into
ConnectionContextStore. The purpose of this class is to provide all the context needed to establish a connection.
This makes SonarWebSocketImpl more functional and therefore testable.

Reviewed By: priteshrnandgaonkar

Differential Revision: D9540089

fbshipit-source-id: 0cd1d69f2b11eaf9f569245a2da14f85cc140427

xplat/Sonar/ConnectionContextStore.cpp

@@ -0,0 +1,134 @@
+#include "ConnectionContextStore.h"
+#include "CertificateUtils.h"
+#include <sys/stat.h>
+#include <iostream>
+#include <fstream>
+#include <folly/json.h>
+
+#define CSR_FILE_NAME "app.csr"
+#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"
+
+#ifdef __ANDROID__
+#include <android/log.h>
+#define SONAR_LOG(message) \
+  __android_log_print(ANDROID_LOG_INFO, "sonar", "sonar: %s", message)
+#else
+#define SONAR_LOG(message) printf("sonar: %s\n", message)
+#endif
+
+using namespace facebook::sonar;
+
+bool fileExists(std::string fileName);
+std::string loadStringFromFile(std::string fileName);
+void writeStringToFile(std::string content, std::string fileName);
+
+ConnectionContextStore::ConnectionContextStore(DeviceData deviceData): deviceData_(deviceData) {}
+
+bool ConnectionContextStore::hasRequiredFiles() {
+  std::string caCert = loadStringFromFile(absoluteFilePath(SONAR_CA_FILE_NAME));
+  std::string clientCert =
+      loadStringFromFile(absoluteFilePath(CLIENT_CERT_FILE_NAME));
+  std::string privateKey =
+      loadStringFromFile(absoluteFilePath(PRIVATE_KEY_FILE));
+
+  if (caCert == "" || clientCert == "" || privateKey == "") {
+    return false;
+  }
+  return true;
+}
+
+std::string ConnectionContextStore::createCertificateSigningRequest() {
+  ensureSonarDirExists();
+  generateCertSigningRequest(
+      deviceData_.appId.c_str(),
+      absoluteFilePath(CSR_FILE_NAME).c_str(),
+      absoluteFilePath(PRIVATE_KEY_FILE).c_str());
+      std::string csr = loadStringFromFile(absoluteFilePath(CSR_FILE_NAME));
+
+  return csr;
+}
+
+std::shared_ptr<SSLContext> ConnectionContextStore::getSSLContext() {
+  std::shared_ptr<folly::SSLContext> sslContext =
+      std::make_shared<folly::SSLContext>();
+  sslContext->loadTrustedCertificates(
+      absoluteFilePath(SONAR_CA_FILE_NAME).c_str());
+  sslContext->setVerificationOption(
+      folly::SSLContext::SSLVerifyPeerEnum::VERIFY);
+  sslContext->loadCertKeyPairFromFiles(
+      absoluteFilePath(CLIENT_CERT_FILE_NAME).c_str(),
+      absoluteFilePath(PRIVATE_KEY_FILE).c_str());
+  sslContext->authenticate(true, false);
+  return sslContext;
+}
+
+std::string ConnectionContextStore::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. */
+  std::string config = loadStringFromFile(absoluteFilePath(CONNECTION_CONFIG_FILE));
+  auto maybeDeviceId = folly::parseJson(config)["deviceId"];
+  return maybeDeviceId.isString() ? maybeDeviceId.getString() : deviceData_.deviceId;
+}
+
+void ConnectionContextStore::storeConnectionConfig(folly::dynamic& config) {
+  std::string json = folly::toJson(config);
+  writeStringToFile(json, absoluteFilePath(CONNECTION_CONFIG_FILE));
+}
+
+std::string ConnectionContextStore::absoluteFilePath(const char* filename) {
+  return std::string(deviceData_.privateAppDirectory + "/sonar/" + filename);
+}
+
+std::string ConnectionContextStore::getCertificateDirectoryPath() {
+  return absoluteFilePath("");
+}
+
+bool ConnectionContextStore::ensureSonarDirExists() {
+  std::string dirPath = absoluteFilePath("");
+  struct stat info;
+  if (stat(dirPath.c_str(), &info) != 0) {
+    int ret = mkdir(dirPath.c_str(), S_IRUSR | S_IWUSR | S_IXUSR);
+    return ret == 0;
+  } else if (info.st_mode & S_IFDIR) {
+    return true;
+  } else {
+    SONAR_LOG(std::string(
+                  "ERROR: Sonar path exists but is not a directory: " + dirPath)
+                  .c_str());
+    return false;
+  }
+}
+
+std::string loadStringFromFile(std::string fileName) {
+  if (!fileExists(fileName)) {
+    return "";
+  }
+  std::stringstream buffer;
+  std::ifstream stream;
+  std::string line;
+  stream.open(fileName.c_str());
+  if (!stream) {
+    SONAR_LOG(
+        std::string("ERROR: Unable to open ifstream: " + fileName).c_str());
+    return "";
+  }
+  buffer << stream.rdbuf();
+  std::string s = buffer.str();
+  return s;
+}
+
+void writeStringToFile(std::string content, std::string fileName) {
+  std::ofstream out(fileName);
+  out << content;
+}
+
+bool fileExists(std::string fileName) {
+  struct stat buffer;
+  return stat(fileName.c_str(), &buffer) == 0;
+}