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

3 files changed, 10 insertions, 151 deletions

diff --git a/src/rng/auto_rng/auto_rng.cpp b/src/rng/auto_rng/auto_rng.cpp
deleted file mode 100644
index 78a7ca21d..000000000
--- a/src/rng/auto_rng/auto_rng.cpp
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
-* Auto Seeded RNG
-* (C) 2008 Jack Lloyd
-*
-* Distributed under the terms of the Botan license
-*/
-
-#include <botan/auto_rng.h>
-#include <botan/libstate.h>
-#include <botan/parsing.h>
-
-#if defined(BOTAN_HAS_RANDPOOL)
-  #include <botan/randpool.h>
-#endif
-
-#if defined(BOTAN_HAS_HMAC_RNG)
-  #include <botan/hmac_rng.h>
-#endif
-
-#if defined(BOTAN_HAS_X931_RNG)
-  #include <botan/x931_rng.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_HIGH_RESOLUTION_TIMER)
-  #include <botan/internal/hres_timer.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM)
-  #include <botan/internal/dev_random.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_EGD)
-  #include <botan/internal/es_egd.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_UNIX)
-  #include <botan/internal/es_unix.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_BEOS)
-  #include <botan/internal/es_beos.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_CAPI)
-  #include <botan/internal/es_capi.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
-  #include <botan/internal/es_win32.h>
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_FTW)
-  #include <botan/internal/es_ftw.h>
-#endif
-
-namespace Botan {
-
-namespace {
-
-/**
-* Add any known entropy sources to this RNG
-*/
-void add_entropy_sources(RandomNumberGenerator* rng)
-   {
-#if defined(BOTAN_HAS_ENTROPY_SRC_HIGH_RESOLUTION_TIMER)
-   rng->add_entropy_source(new High_Resolution_Timestamp);
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM)
-   rng->add_entropy_source(
-      new Device_EntropySource(
-         split_on("/dev/urandom:/dev/random:/dev/srandom", ':')
-         )
-      );
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_EGD)
-   rng->add_entropy_source(
-      new EGD_EntropySource(split_on("/var/run/egd-pool:/dev/egd-pool", ':'))
-      );
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_CAPI)
-   rng->add_entropy_source(new Win32_CAPI_EntropySource);
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_FTW)
-   rng->add_entropy_source(new FTW_EntropySource("/proc"));
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
-   rng->add_entropy_source(new Win32_EntropySource);
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_BEOS)
-   rng->add_entropy_source(new BeOS_EntropySource);
-#endif
-
-#if defined(BOTAN_HAS_ENTROPY_SRC_UNIX)
-   rng->add_entropy_source(
-      new Unix_EntropySource(split_on("/bin:/sbin:/usr/bin:/usr/sbin", ':'))
-      );
-#endif
-   }
-
-}
-
-AutoSeeded_RNG::AutoSeeded_RNG(u32bit poll_bits)
-   {
-   rng = 0;
-
-   Algorithm_Factory& af = global_state().algorithm_factory();
-
-#if defined(BOTAN_HAS_HMAC_RNG)
-
-   rng = new HMAC_RNG(af.make_mac("HMAC(SHA-512)"),
-                      af.make_mac("HMAC(SHA-256)"));
-
-#elif defined(BOTAN_HAS_RANDPOOL) && defined(BOTAN_HAS_AES)
-
-   rng = new Randpool(af.make_block_cipher("AES-256"),
-                      af.make_mac("HMAC(SHA-256)"));
-
-#endif
-
-   if(!rng)
-      throw Internal_Error("No usable RNG found enabled in build");
-
-   /* If X9.31 is available, use it to wrap the other RNG as a failsafe */
-#if defined(BOTAN_HAS_X931_RNG) && defined(BOTAN_HAS_AES)
-
-   rng = new ANSI_X931_RNG(af.make_block_cipher("AES-256"), rng);
-
-#endif
-
-   add_entropy_sources(rng);
-
-   rng->reseed(poll_bits);
-   }
-
-}
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;
diff --git a/src/rng/auto_rng/info.txt b/src/rng/auto_rng/info.txt
index 0f7cee282..6f98a65f4 100644
--- a/src/rng/auto_rng/info.txt
+++ b/src/rng/auto_rng/info.txt
@@ -1,6 +1,5 @@
 define AUTO_SEEDING_RNG
 
 <requires>
-hmac
-sha2
+libstate
 </requires>