Move rng.h from core to rng

1 files changed, 107 insertions, 0 deletions

diff --git a/src/rng/rng.h b/src/rng/rng.h
new file mode 100644
index 000000000..20f2e47b1
--- /dev/null
+++ b/src/rng/rng.h
@@ -0,0 +1,107 @@
+/*************************************************
+* RandomNumberGenerator Header File              *
+* (C) 1999-2008 Jack Lloyd                       *
+*************************************************/
+
+#ifndef BOTAN_RANDOM_NUMBER_GENERATOR_H__
+#define BOTAN_RANDOM_NUMBER_GENERATOR_H__
+
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+/*************************************************
+* Entropy Source                                 *
+*************************************************/
+class BOTAN_DLL EntropySource
+   {
+   public:
+      virtual u32bit slow_poll(byte[], u32bit) = 0;
+      virtual u32bit fast_poll(byte[], u32bit);
+      virtual ~EntropySource() {}
+   };
+
+/**
+* This class represents a random number (RNG) generator object.
+*/
+class BOTAN_DLL RandomNumberGenerator
+   {
+   public:
+      /**
+      * Create a seeded and active RNG object for general application use
+      */
+      static RandomNumberGenerator* make_rng();
+
+      /**
+      * Randomize a byte array.
+      * @param output the byte array to hold the random output.
+      * @param length the length of the byte array output.
+      */
+      virtual void randomize(byte output[], u32bit length) = 0;
+
+      /**
+      * Return a random byte
+      * @return random byte
+      */
+      byte next_byte();
+
+      /**
+      * Check whether this RNG is seeded.
+      * @return true if this RNG was already seeded, false otherwise.
+      */
+      virtual bool is_seeded() const { return true; }
+
+      /**
+      * Clear all internally held values of this RNG.
+      */
+      virtual void clear() throw() = 0;
+
+      /**
+      * Return the name of this object
+      */
+      virtual std::string name() const = 0;
+
+      /**
+      * Seed this RNG using the entropy sources it contains.
+      */
+      virtual void reseed() {}
+
+      /**
+      * Add this entropy source to the RNG object
+      * @param source the entropy source which will be retained and used by RNG
+      */
+      virtual void add_entropy_source(EntropySource* source) = 0;
+
+      /**
+      * Add entropy to this RNG.
+      * @param in a byte array containg the entropy to be added
+      * @param length the length of the byte array in
+      */
+      virtual void add_entropy(const byte in[], u32bit length) = 0;
+
+      RandomNumberGenerator() {}
+      virtual ~RandomNumberGenerator() {}
+   private:
+      RandomNumberGenerator(const RandomNumberGenerator&) {}
+      RandomNumberGenerator& operator=(const RandomNumberGenerator&)
+         { return (*this); }
+   };
+
+/*************************************************
+* Null Random Number Generator                   *
+*************************************************/
+class BOTAN_DLL Null_RNG : public RandomNumberGenerator
+   {
+   public:
+      void randomize(byte[], u32bit) { throw PRNG_Unseeded("Null_RNG"); }
+      void clear() throw() {}
+      std::string name() const { return "Null_RNG"; }
+
+      bool is_seeded() const { return false; }
+      void add_entropy(const byte[], u32bit) {}
+      void add_entropy_source(EntropySource* es) { delete es; }
+   };
+
+}
+
+#endif