container: root: src: add bitcoin plugin support

- Adds bitcoin plugin support to `Random` specialization/implementation
  * Currently only supports one of bitcoin's RNG's (`FastRandomContext`)

container/src/root/src/internal/impl/random.hh

@@ -19,6 +19,7 @@
 //! \author Aaron Fiore (Founder, Evergreen Crypto LLC)
 //! \note File intended to be loaded into ROOT.cern framework / Cling interpreter
 //! \since docker-finance 1.0.0
+//! \todo C++20 refactor
 
 #ifndef CONTAINER_SRC_ROOT_SRC_INTERNAL_IMPL_RANDOM_HH_
 #define CONTAINER_SRC_ROOT_SRC_INTERNAL_IMPL_RANDOM_HH_
@@ -259,6 +260,69 @@ class Random : public common::RandomImpl<libsodium::Random>
 };
 }  // namespace libsodium
 
+#ifdef __DFI_PLUGIN_BITCOIN__
+//! \namespace dfi::crypto::impl::bitcoin
+//! \since docker-finance 1.1.0
+namespace bitcoin
+{
+//! \concept dfi::crypto::impl::bitcoin::RType
+//! \brief Random number type
+//! \details Requirements include that "interface" specialization
+//!   has not changed and that given type is supported by bitcoin.
+//! \since docker-finance 1.1.0
+template <typename t_random>
+concept RType =
+    ::dfi::internal::type::is_real_integral<t_random>::value
+    && (std::same_as<t_random, uint32_t> || std::same_as<t_random, uint64_t>);
+
+//! \brief Implements Random API with bitcoin
+//! \ingroup cpp_API_impl
+//! \since docker-finance 1.1.0
+//! \todo span/bytes
+//! \todo reseed
+//! \todo insecure RNG option
+class Random : public common::RandomImpl<bitcoin::Random>
+{
+ public:
+  Random() = default;
+  ~Random() = default;
+
+  Random(const Random&) = delete;
+  Random& operator=(const Random&) = delete;
+
+  Random(Random&&) = delete;
+  Random& operator=(Random&&) = delete;
+
+ private:
+  //! \brief Implements random number generator
+  template <RType t_random>
+  t_random generate_impl()
+  {
+    if constexpr (std::same_as<t_random, uint32_t>)
+      {
+        return m_ctx.rand32();
+      }
+    else if constexpr (std::same_as<t_random, uint64_t>)
+      {
+        return m_ctx.rand64();
+      }
+  }
+
+ public:
+  //! \brief Generate random number
+  template <RType t_random>
+  t_random generate()
+  {
+    return this->generate_impl<t_random>();
+  }
+
+ private:
+  //! \warning Bitcoin's RNG is not thread-safe (but dfi's CRTP provides external locks, by default)
+  ::FastRandomContext m_ctx;
+};
+}  // namespace bitcoin
+#endif
+
 }  // namespace impl
 }  // namespace crypto
 }  // namespace dfi

container/src/root/src/random.hh

@@ -118,6 +118,20 @@ namespace libsodium
 using Random = ::dfi::crypto::common::Random<impl::libsodium::Random>;
 }  // namespace libsodium
 
+#ifdef __DFI_PLUGIN_BITCOIN__
+//! \namespace dfi::crypto::bitcoin
+//! \brief Public-facing API namespace (bitcoin)
+//! \since docker-finance 1.1.0
+namespace bitcoin
+{
+//! \brief bitcoin Random API specialization ("interface" / implementation)
+//! \note For public consumption
+//! \ingroup cpp_API
+//! \since docker-finance 1.1.0
+using Random = ::dfi::crypto::common::Random<impl::bitcoin::Random>;
+}  // namespace bitcoin
+#endif
+
 }  // namespace crypto
 }  // namespace dfi