1 files changed, 50 insertions, 0 deletions
diff --git a/src/lib/rng/hmac_drbg/hmac_drbg.h b/src/lib/rng/hmac_drbg/hmac_drbg.h
new file mode 100644
index 000000000..43729c7fa
--- /dev/null
+++ b/src/lib/rng/hmac_drbg/hmac_drbg.h
@@ -0,0 +1,50 @@
+/*
+* HMAC_DRBG (SP800-90A)
+* (C) 2014 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_HMAC_DRBG_H__
+#define BOTAN_HMAC_DRBG_H__
+
+#include <botan/rng.h>
+#include <botan/mac.h>
+
+namespace Botan {
+
+/**
+* HMAC_DRBG (SP800-90A)
+*/
+class BOTAN_DLL HMAC_DRBG : public RandomNumberGenerator
+   {
+   public:
+      void randomize(byte buf[], size_t buf_len);
+      bool is_seeded() const;
+      void clear();
+      std::string name() const;
+
+      void reseed(size_t poll_bits);
+
+      void add_entropy(const byte input[], size_t input_len);
+
+      /**
+      * @param mac the underlying mac function (eg HMAC(SHA-512))
+      * @param underlying_rng RNG used generating inputs (eg HMAC_RNG)
+      */
+      HMAC_DRBG(MessageAuthenticationCode* mac,
+                RandomNumberGenerator* underlying_rng);
+
+   private:
+      void update(const byte input[], size_t input_len);
+
+      std::unique_ptr<MessageAuthenticationCode> m_mac;
+      std::unique_ptr<RandomNumberGenerator> m_prng;
+
+      secure_vector<byte> m_K, m_V;
+      size_t m_reseed_counter;
+   };
+
+}
+
+#endif