Wrap OpenSSL's random number generator in fc clothing

include/fc/crypto/rand.hpp

@@ -0,0 +1,8 @@
+#pragma once
+
+namespace fc {
+
+  /* provides access to the OpenSSL random number generator */
+  void rand_bytes(char* buf, int count);
+  void rand_pseudo_bytes(char* buf, int count);
+} // namespace fc 

src/crypto/rand.cpp

@@ -0,0 +1,25 @@
+#include <openssl/rand.h>
+#include <fc/crypto/openssl.hpp>
+#include <fc/exception/exception.hpp>
+#include <fc/fwd_impl.hpp>
+
+
+namespace fc {
+
+static int init = init_openssl();
+
+void rand_bytes(char* buf, int count)
+{
+  int result = RAND_bytes((unsigned char*)buf, count);
+  if (result != 1)
+    FC_THROW("Error calling OpenSSL's RAND_bytes(): ${code}", ("code", (uint32_t)ERR_get_error()));
+}
+
+void rand_pseudo_bytes(char* buf, int count)
+{
+  int result = RAND_pseudo_bytes((unsigned char*)buf, count);
+  if (result == -1)
+    FC_THROW("Error calling OpenSSL's RAND_pseudo_bytes(): ${code}", ("code", (uint32_t)ERR_get_error()));
+}
+
+}  // namespace fc