Revamp entropy polling

Remove Entropy_Accumulator, instead have entropy sources directly
add entropy to the RNG.

1 files changed, 8 insertions, 65 deletions

diff --git a/src/lib/entropy/entropy_src.h b/src/lib/entropy/entropy_src.h
index 1726d05b8..64d988e7c 100644
--- a/src/lib/entropy/entropy_src.h
+++ b/src/lib/entropy/entropy_src.h
@@ -8,73 +8,12 @@
 #ifndef BOTAN_ENTROPY_H__
 #define BOTAN_ENTROPY_H__
 
-#include <botan/secmem.h>
+#include <botan/rng.h>
 #include <string>
 #include <chrono>
-#include <functional>
 
 namespace Botan {
 
-class RandomNumberGenerator;
-
-/**
-* Class used to accumulate the poll results of EntropySources
-*/
-class BOTAN_DLL Entropy_Accumulator final
-   {
-   public:
-      /**
-      * Initialize an Entropy_Accumulator
-      *
-      * @param accum will be called with poll results, first params the data and
-      * length, the second a best estimate of min-entropy for the entire buffer;
-      * out of an abundance of caution this will be zero for many sources.
-      * accum should return true if it wants the polling to stop, though it may
-      * still be called again a few more times, and should be careful to return
-      * true then as well.
-      */
-      explicit Entropy_Accumulator(std::function<bool (const byte[], size_t, double)> accum) :
-         m_accum_fn(accum) {}
-
-      /**
-      * @return if our polling goal has been achieved
-      */
-      bool polling_goal_achieved() const { return m_done; }
-
-      bool polling_finished() const { return m_done; }
-
-      /**
-      * Add entropy to the accumulator
-      * @param bytes the input bytes
-      * @param length specifies how many bytes the input is
-      * @param entropy_bits_per_byte is a best guess at how much
-      * entropy per byte is in this input
-      */
-      void add(const void* bytes, size_t length, double entropy_bits_per_byte)
-         {
-         m_done = m_accum_fn(reinterpret_cast<const byte*>(bytes),
-                             length, entropy_bits_per_byte * length) || m_done;
-         }
-
-      /**
-      * Add entropy to the accumulator
-      * @param v is some value
-      * @param entropy_bits_per_byte is a best guess at how much
-      * entropy per byte is in this input
-      */
-      template<typename T>
-      void add(const T& v, double entropy_bits_per_byte)
-         {
-         add(&v, sizeof(T), entropy_bits_per_byte);
-         }
-
-      secure_vector<byte>& get_io_buf(size_t sz) { m_io_buf.resize(sz); return m_io_buf; }
-   private:
-      std::function<bool (const byte[], size_t, double)> m_accum_fn;
-      secure_vector<byte> m_io_buf;
-      bool m_done = false;
-   };
-
 /**
 * Abstract interface to a source of entropy
 */
@@ -96,9 +35,10 @@ class BOTAN_DLL Entropy_Source
 
       /**
       * Perform an entropy gathering poll
-      * @param accum is an accumulator object that will be given entropy
+      * @param rng will be provided with entropy via calls to add_entropy
+      @ @return conservative estimate of actual entropy added to rng during poll
       */
-      virtual void poll(Entropy_Accumulator& accum) = 0;
+      virtual size_t poll(RandomNumberGenerator& rng) = 0;
 
       virtual ~Entropy_Source() {}
    };
@@ -116,7 +56,10 @@ class BOTAN_DLL Entropy_Sources final
                   size_t bits,
                   std::chrono::milliseconds timeout);
 
-      bool poll_just(Entropy_Accumulator& accum, const std::string& src);
+      /**
+      * Poll just a single named source. Ordinally only used for testing
+      */
+      size_t poll_just(RandomNumberGenerator& rng, const std::string& src);
 
       Entropy_Sources() {}
       explicit Entropy_Sources(const std::vector<std::string>& sources);