New reseed_with_sources call on RNGs

Provides an easier way for an application to configure a list of
entropy sources they'd like to use, or add a custom entropy source to
their seeding.

Exposes some toggles for the global/default entropy sources to build.h

Adds basic entropy tests which runs the polls and does sanity checking
on the results, including compression tests if available. These are
less useful for the CSPRNG outputs but a good check for the ones
producing plain ASCII like the /proc reader.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/tests/test_rng.h b/src/tests/test_rng.h
index f1d40f7f1..7d30fd6cc 100644
--- a/src/tests/test_rng.h
+++ b/src/tests/test_rng.h
@@ -30,7 +30,9 @@ class Fixed_Output_RNG : public Botan::RandomNumberGenerator
          return out;
          }
 
-      void reseed(size_t) override {}
+      size_t reseed_with_sources(Botan::Entropy_Sources&,
+                                 size_t,
+                                 std::chrono::milliseconds) { return 0; }
 
       void randomize(byte out[], size_t len) override
          {