Security: handle empty name in normalizeName

2 files changed, 9 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index c8dbafa4..7440f632 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2013-10-05  Jay Berkenbilt  <ejb@ql.org>
 
+	* Security fix: properly handle empty strings in
+	QPDF_Name::normalizeName.  The empty string is not a valid name
+	and would never be parsed as a name, so there were no known
+	conditions where this method could be called with an empty string.
+
 	* Security fix: perform additional argument sanity checks when
 	reading bit streams.
 
diff --git a/libqpdf/QPDF_Name.cc b/libqpdf/QPDF_Name.cc
index 9adb25b5..26bd8263 100644
--- a/libqpdf/QPDF_Name.cc
+++ b/libqpdf/QPDF_Name.cc
@@ -16,6 +16,10 @@ QPDF_Name::~QPDF_Name()
 std::string
 QPDF_Name::normalizeName(std::string const& name)
 {
+    if (name.empty())
+    {
+	return name;
+    }
     std::string result;
     result += name[0];
     for (unsigned int i = 1; i < name.length(); ++i)