There are some nasty API problems that are caused by having to pass a

PRNG everywhere. The removal of the global PRNG was generated by a
desire to remove the global library state entirely. However the real
point of this was to remove the use of globally visible _mutable_
state; of the mutable state, the PRNG is probably the least important,
and the most useful to share. And it seems unlikely that thread
contention would be a major issue in the PRNG.

Add back a global PRNG to Library_State. Use lazy initialization, so
apps that don't ever use a PRNG don't need a seeding step. Then have
AutoSeeded_RNG call that global PRNG.

Offer once again

RandomNumberGenerator& Library_State::global_rng();

which returns a reference to the global PRNG.

This RNG object serializes access to itself with a mutex.

Remove the hack known as Blinding::choose_nonce, replace with using
the global PRNG to choose a blinding nonce

1 files changed, 9 insertions, 8 deletions

diff --git a/src/rng/auto_rng/auto_rng.h b/src/rng/auto_rng/auto_rng.h
index a15b11b13..9a93fee8f 100644
--- a/src/rng/auto_rng/auto_rng.h
+++ b/src/rng/auto_rng/auto_rng.h
@@ -9,31 +9,32 @@
 #define BOTAN_AUTO_SEEDING_RNG_H__
 
 #include <botan/rng.h>
+#include <botan/libstate.h>
 #include <string>
 
 namespace Botan {
 
-/**
-* RNG that attempts to seed itself
-*/
 class BOTAN_DLL AutoSeeded_RNG : public RandomNumberGenerator
    {
    public:
       void randomize(byte out[], u32bit len)
          { rng->randomize(out, len); }
-      bool is_seeded() const
-         { return rng->is_seeded(); }
+
+      bool is_seeded() const { return rng->is_seeded(); }
+
       void clear() { rng->clear(); }
-      std::string name() const
-         { return "AutoSeeded(" + rng->name() + ")"; }
+
+      std::string name() const { return rng->name(); }
 
       void reseed(u32bit poll_bits = 256) { rng->reseed(poll_bits); }
+
       void add_entropy_source(EntropySource* es)
          { rng->add_entropy_source(es); }
+
       void add_entropy(const byte in[], u32bit len)
          { rng->add_entropy(in, len); }
 
-      AutoSeeded_RNG(u32bit poll_bits = 256);
+      AutoSeeded_RNG() { rng = &global_state().global_rng(); }
       ~AutoSeeded_RNG() { delete rng; }
    private:
       RandomNumberGenerator* rng;