Prevent information about file existence outside the allowed paths to leak by mimicing boost::filesystem::weakly_canonical.

1 files changed, 20 insertions, 0 deletions

diff --git a/libdevcore/CommonIO.cpp b/libdevcore/CommonIO.cpp
index 6526baf9..0063a8d4 100644
--- a/libdevcore/CommonIO.cpp
+++ b/libdevcore/CommonIO.cpp
@@ -167,3 +167,23 @@ int dev::readStandardInputChar()
 	DisableConsoleBuffering disableConsoleBuffering;
 	return cin.get();
 }
+
+boost::filesystem::path dev::weaklyCanonicalFilesystemPath(boost::filesystem::path const &_path)
+{
+	if (boost::filesystem::exists(_path))
+		return boost::filesystem::canonical(_path);
+	else
+	{
+		boost::filesystem::path head(_path);
+		boost::filesystem::path tail;
+		for (auto it = --_path.end(); !head.empty(); --it)
+		{
+			if (boost::filesystem::exists(head))
+				break;
+			tail = (*it) / tail;
+			head.remove_filename();
+		}
+		head = boost::filesystem::canonical(head);
+		return head / tail;
+	}
+}