Add interfaces for add_entropy_source and add_entropy to

RandomNumberGenerator, and make ANSI_X931_PRNG's implementations just
forward the arguments to the underlying RNG. This allows seeding the RNG
even if no entropy modules are loaded into the library. Also it allows
actually adding user-specified data; to do it otherwise would require
creating the RNG objects yourself and retaining a pointer to the Randpool,
which is pretty bogus.

Move Null_RNG to rng.h

5 files changed, 41 insertions, 19 deletions

diff --git a/checks/common.h b/checks/common.h
index e42fa8e44..06cb638ee 100644
--- a/checks/common.h
+++ b/checks/common.h
@@ -78,21 +78,19 @@ class Fixed_Output_RNG : public Botan::RandomNumberGenerator
 
       std::string name() const { return "Fixed_Output_RNG"; }
 
-      void clear() throw() {}
+      void add_entropy_source(Botan::EntropySource* src) { delete src; }
+      void add_entropy(const byte[], u32bit) {};
 
-      void add_randomness(const byte in[], u32bit len) throw()
-         {
-         buf.insert(buf.end(), in, in + len);
-         }
+      void clear() throw() {}
 
-      Fixed_Output_RNG(const Botan::SecureVector<byte>& x)
+      Fixed_Output_RNG(const Botan::SecureVector<byte>& in)
          {
-         add_randomness(x.begin(), x.size());
+         buf.insert(buf.end(), in.begin(), in.begin() + in.size());
          }
-      Fixed_Output_RNG(const std::string& in)
+      Fixed_Output_RNG(const std::string& in_str)
          {
-         Botan::SecureVector<byte> x = decode_hex(in);
-         add_randomness(x.begin(), x.size());
+         Botan::SecureVector<byte> in = decode_hex(in_str);
+         buf.insert(buf.end(), in.begin(), in.begin() + in.size());
          }
 
       Fixed_Output_RNG() {}
diff --git a/include/rng.h b/include/rng.h
index 78edc1554..e09a3e939 100644
--- a/include/rng.h
+++ b/include/rng.h
@@ -35,11 +35,25 @@ class BOTAN_DLL RandomNumberGenerator
 
       byte next_byte();
 
-      virtual void reseed() {};
+      virtual void reseed() {}
+      virtual void add_entropy_source(EntropySource*) = 0;
+      virtual void add_entropy(const byte[], u32bit) = 0;
 
       virtual ~RandomNumberGenerator() {}
    };
 
+/*************************************************
+* Null Random Number Generator                   *
+*************************************************/
+class BOTAN_DLL Null_RNG : public RandomNumberGenerator
+   {
+   public:
+      void randomize(byte[], u32bit) { throw PRNG_Unseeded("Null_RNG"); }
+      bool is_seeded() const { return false; }
+      void add_entropy(const byte[], u32bit) {}
+      void add_entropy_source(EntropySource* es) { delete es; }
+   };
+
 }
 
 #endif
diff --git a/include/x931_rng.h b/include/x931_rng.h
index 2ba39361d..7914b605d 100644
--- a/include/x931_rng.h
+++ b/include/x931_rng.h
@@ -23,6 +23,8 @@ class BOTAN_DLL ANSI_X931_RNG : public RandomNumberGenerator
       std::string name() const;
 
       void reseed();
+      void add_entropy_source(EntropySource*);
+      void add_entropy(const byte[], u32bit);
 
       ANSI_X931_RNG(const std::string&, RandomNumberGenerator*);
       ~ANSI_X931_RNG();
diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index f52208b3d..06bb44bca 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -367,14 +367,6 @@ PK_Verifier_wo_MR::PK_Verifier_wo_MR(const PK_Verifying_wo_MR_Key& k,
 bool PK_Verifier_wo_MR::validate_signature(const MemoryRegion<byte>& msg,
                                            const byte sig[], u32bit sig_len)
    {
-   class Null_RNG : public RandomNumberGenerator
-      {
-      public:
-         void randomize(byte[], u32bit) { throw PRNG_Unseeded("Null_RNG"); }
-         bool is_seeded() const { return false; }
-         void add_randomness(const byte[], u32bit) {}
-      };
-
    Null_RNG rng;
 
    SecureVector<byte> encoded =
diff --git a/src/x931_rng.cpp b/src/x931_rng.cpp
index 68d633df4..8f454dcb8 100644
--- a/src/x931_rng.cpp
+++ b/src/x931_rng.cpp
@@ -70,6 +70,22 @@ void ANSI_X931_RNG::reseed()
    }
 
 /*************************************************
+* Add a entropy source to the underlying PRNG    *
+*************************************************/
+void ANSI_X931_RNG::add_entropy_source(EntropySource* src)
+   {
+   prng->add_entropy_source(src);
+   }
+
+/*************************************************
+* Add some entropy to the underlying PRNG        *
+*************************************************/
+void ANSI_X931_RNG::add_entropy(const byte input[], u32bit length)
+   {
+   prng->add_entropy(input, length);
+   }
+
+/*************************************************
 * Check if the the PRNG is seeded                *
 *************************************************/
 bool ANSI_X931_RNG::is_seeded() const