Move RPC file related stuff into RpcAddressFile

3 files changed, 124 insertions, 55 deletions

diff --git a/app/lib/backend.js b/app/lib/backend.js
index b24b495449..39521d8edb 100644
--- a/app/lib/backend.js
+++ b/app/lib/backend.js
@@ -8,6 +8,7 @@ import connectionActions from '../redux/connection/actions';
 import settingsActions from '../redux/settings/actions';
 import { push } from 'react-router-redux';
 
+import type { RpcCredentials } from './rpc-address-file';
 import type { ReduxStore } from '../redux/store';
 import type { AccountToken, BackendState, RelaySettingsUpdate } from './ipc-facade';
 import type { ConnectionState } from '../redux/connection/reducers';
@@ -74,32 +75,16 @@ export class UnknownError extends Error {
   }
 }
 
-export type IpcCredentials = {
-  connectionString: string,
-  sharedSecret: string,
-};
-export function parseIpcCredentials(data: string): ?IpcCredentials {
-  const [connectionString, sharedSecret] = data.split('\n', 2);
-  if (connectionString && sharedSecret !== undefined) {
-    return {
-      connectionString,
-      sharedSecret,
-    };
-  } else {
-    return null;
-  }
-}
-
 /**
  * Backend implementation
  */
 export class Backend {
   _ipc: IpcFacade;
-  _credentials: ?IpcCredentials;
+  _credentials: ?RpcCredentials;
   _authenticationPromise: ?Promise<void>;
   _store: ReduxStore;
 
-  constructor(store: ReduxStore, credentials?: IpcCredentials, ipc: ?IpcFacade) {
+  constructor(store: ReduxStore, credentials?: RpcCredentials, ipc: ?IpcFacade) {
     this._store = store;
     this._credentials = credentials;
 
@@ -116,7 +101,7 @@ export class Backend {
     }
   }
 
-  setCredentials(credentials: IpcCredentials) {
+  setCredentials(credentials: RpcCredentials) {
     log.debug('Got connection info to backend', credentials.connectionString);
     this._credentials = credentials;
 
diff --git a/app/lib/rpc-address-file.js b/app/lib/rpc-address-file.js
new file mode 100644
index 0000000000..5185ddc749
--- /dev/null
+++ b/app/lib/rpc-address-file.js
@@ -0,0 +1,120 @@
+// @flow
+
+import fs from 'fs';
+import path from 'path';
+import { promisify } from 'util';
+import { getSystemTemporaryDirectory } from './tempdir';
+
+const fsReadFileAsync = promisify(fs.readFile);
+
+const POLL_INTERVAL = 200;
+
+const appDirectoryName = 'Mullvad VPN';
+
+export type RpcCredentials = {
+  connectionString: string,
+  sharedSecret: string,
+};
+
+export class RpcAddressFile {
+  _filePath: string;
+  _pollIntervalId: ?IntervalID;
+  _pollPromise: ?Promise<void>;
+
+  constructor() {
+    this._filePath = getRpcAddressFilePath();
+  }
+
+  get filePath(): string {
+    return this._filePath;
+  }
+
+  poll(): Promise<void> {
+    let promise = this._pollPromise;
+
+    if (!promise) {
+      promise = new Promise((resolve, _reject) => {
+        const timer = setInterval(() => {
+          fs.exists(this._filePath, (exists) => {
+            if (exists) {
+              clearInterval(timer);
+              resolve();
+
+              this._pollPromise = null;
+            }
+          });
+        }, POLL_INTERVAL);
+      });
+
+      this._pollPromise = promise;
+    }
+
+    return promise;
+  }
+
+  isTrusted() {
+    const filePath = this._filePath;
+    switch (process.platform) {
+      case 'win32':
+        return isOwnedByLocalSystem(filePath);
+      case 'darwin':
+      case 'linux':
+        return isOwnedAndOnlyWritableByRoot(filePath);
+      default:
+        throw new Error(`Unknown platform: ${process.platform}`);
+    }
+  }
+
+  async waitUntilExists(): Promise<RpcCredentials> {
+    const data = await fsReadFileAsync(this._filePath, 'utf8');
+    const [connectionString, sharedSecret] = data.split('\n', 2);
+
+    if (connectionString && sharedSecret !== undefined) {
+      return {
+        connectionString,
+        sharedSecret,
+      };
+    } else {
+      throw new Error('Cannot parse the RPC address file');
+    }
+  }
+}
+
+function getRpcAddressFilePath() {
+  const rpcAddressFileName = '.mullvad_rpc_address';
+
+  switch (process.platform) {
+    case 'win32': {
+      // Windows: %ALLUSERSPROFILE%\{appname}
+      const programDataDirectory = process.env.ALLUSERSPROFILE;
+      if (programDataDirectory) {
+        const appDataDirectory = path.join(programDataDirectory, appDirectoryName);
+        return path.join(appDataDirectory, rpcAddressFileName);
+      } else {
+        throw new Error('Missing %ALLUSERSPROFILE% environment variable');
+      }
+    }
+    default:
+      return path.join(getSystemTemporaryDirectory(), rpcAddressFileName);
+  }
+}
+
+function isOwnedAndOnlyWritableByRoot(path: string): boolean {
+  const stat = fs.statSync(path);
+  const isOwnedByRoot = stat.uid === 0;
+  const isOnlyWritableByOwner = (stat.mode & parseInt('022', 8)) === 0;
+
+  return isOwnedByRoot && isOnlyWritableByOwner;
+}
+
+function isOwnedByLocalSystem(path: string): boolean {
+  // $FlowFixMe: this module is only available on Windows
+  const winsec = require('windows-security');
+  const ownerSid = winsec.getFileOwnerSid(path, null);
+  const isWellKnownSid = winsec.isWellKnownSid(
+    ownerSid,
+    winsec.WellKnownSid.BuiltinAdministratorsSid,
+  );
+
+  return isWellKnownSid;
+}
diff --git a/app/lib/rpc-file-security.js b/app/lib/rpc-file-security.js
deleted file mode 100644
index fa88111c02..0000000000
--- a/app/lib/rpc-file-security.js
+++ /dev/null
@@ -1,36 +0,0 @@
-// @flow
-
-import fs from 'fs';
-
-export function canTrustRpcAddressFile(path: string): boolean {
-  const platform = process.platform;
-  switch (platform) {
-    case 'win32':
-      return isOwnedByLocalSystem(path);
-    case 'darwin':
-    case 'linux':
-      return isOwnedAndOnlyWritableByRoot(path);
-    default:
-      throw new Error(`Unknown platform: ${platform}`);
-  }
-}
-
-function isOwnedAndOnlyWritableByRoot(path: string): boolean {
-  const stat = fs.statSync(path);
-  const isOwnedByRoot = stat.uid === 0;
-  const isOnlyWritableByOwner = (stat.mode & parseInt('022', 8)) === 0;
-
-  return isOwnedByRoot && isOnlyWritableByOwner;
-}
-
-function isOwnedByLocalSystem(path: string): boolean {
-  // $FlowFixMe: this module is only available on Windows
-  const winsec = require('windows-security');
-  const ownerSid = winsec.getFileOwnerSid(path, null);
-  const isWellKnownSid = winsec.isWellKnownSid(
-    ownerSid,
-    winsec.WellKnownSid.BuiltinAdministratorsSid,
-  );
-
-  return isWellKnownSid;
-}