1 files changed, 32 insertions, 0 deletions
diff --git a/app/lib/rpc-file-security.js b/app/lib/rpc-file-security.js
new file mode 100644
index 0000000000..da777d9b78
--- /dev/null
+++ b/app/lib/rpc-file-security.js
@@ -0,0 +1,32 @@
+// @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 {
+  const winsec = require('windows-security');
+  const ownerSid = winsec.getFileOwnerSid(path, null);
+  const isWellKnownSid = winsec.isWellKnownSid(ownerSid, winsec.WellKnownSid.LocalSystemSid);
+
+  return isWellKnownSid;
+}
+\ No newline at end of file