Imported Upstream version 5.0.1

Change-Id: Idc5b8effa25ad1c63f76999f5fd76918e52ecc59
Signed-off-by: DongHun Kwak <dh0128.kwak@samsung.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/TODO b/TODO
index 6df0fcf..f7e5549 100644
--- a/TODO
+++ b/TODO
@@ -64,6 +64,11 @@
 General
 =======
 
+ * When decrypting files with /R=6, hash_V5 is called more than once
+   with the same inputs.  Caching the results or refactoring to reduce
+   the number of identical calls could improve performance for
+   workloads that involve processing large numbers of small files.
+
  * Consider providing a Windows installer for qpdf using NSIS.
 
  * Consider adding a method to balance the pages tree.  It would call
@@ -71,12 +76,11 @@ General
    and replace the /Pages key of the root dictionary with the new
    tree.
 
- * Improve the random number seed to make it more secure so that we
-   have stronger random numbers, particularly when multiple files are
-   generated in the same second.  This code may need to be
-   OS-specific.  Probably we should add a method in QUtil to seed with
-   a strong random number and call this automatically the first time
-   QUtil::random() is called.
+ * Secure random number generation could be made more efficient by
+   using a local static to ensure a single random device or crypt
+   provider as long as this can be done in a thread-safe fashion.  In
+   the initial implementation, this is being skipped to avoid having
+   to add any dependencies on threading libraries.
 
  * Study what's required to support savable forms that can be saved by
    Adobe Reader.  Does this require actually signing the document with