Add Curve class, and Helios & Selene classes that derive from Curve

src/fcmp/curve_trees.h

@@ -133,9 +133,9 @@ public:
         crypto::derive_key_image_generator(O, I);
 
         return LeafTuple{
-            .O_x = m_c2.ed_25519_point_to_scalar(O),
+            .O_x = fcmp::tower_cycle::ed_25519_point_to_scalar(O),
-            .I_x = m_c2.ed_25519_point_to_scalar(I),
+            .I_x = fcmp::tower_cycle::ed_25519_point_to_scalar(I),
-            .C_x = m_c2.ed_25519_point_to_scalar(C)
+            .C_x = fcmp::tower_cycle::ed_25519_point_to_scalar(C)
         };
     };
 
@@ -265,8 +265,7 @@ private:
         fcmp::tower_cycle::extend_zeroes(curve, new_children.size(), prior_children);
 
         return curve.hash_grow(
-                curve.GENERATORS,
+                curve.m_hash_init_point,
-                curve.HASH_INIT_POINT,
                 0,/*offset*/
                 typename C::Chunk{prior_children.data(), prior_children.size()},
                 new_children
@@ -286,7 +285,6 @@ private:
         fcmp::tower_cycle::extend_zeroes(m_c2, new_children.size(), prior_children);
 
         return m_c2.hash_grow(
-                m_c2.GENERATORS,
                 last_chunk_ptr->last_parent,
                 last_chunk_ptr->child_offset,
                 typename C2::Chunk{prior_children.data(), prior_children.size()},
@@ -333,7 +331,6 @@ private:
         }
 
         return curve.hash_grow(
-                curve.GENERATORS,
                 last_chunk_ptr->last_parent,
                 offset,
                 typename C::Chunk{prior_children.data(), prior_children.size()},
@@ -505,6 +502,7 @@ private:
         }
     }
 
+//member variables
 private:
     const C1 &m_c1;
     const C2 &m_c2;

src/fcmp/tower_cycle.cpp

@@ -26,28 +26,125 @@
 // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#include "string_tools.h"
 #include "tower_cycle.h"
 
 namespace fcmp
 {
 namespace tower_cycle
 {
-
-namespace helios
-{
 //----------------------------------------------------------------------------------------------------------------------
-SeleneScalar Helios::point_to_cycle_scalar(const Helios::Point &point) const
+//----------------------------------------------------------------------------------------------------------------------
+Helios::CycleScalar Helios::point_to_cycle_scalar(const Helios::Point &point) const
 {
     return fcmp_rust::helios_point_to_selene_scalar(point);
-};
+}
 //----------------------------------------------------------------------------------------------------------------------
-} //namespace helios
+Selene::CycleScalar Selene::point_to_cycle_scalar(const Selene::Point &point) const
-//----------------------------------------------------------------------------------------------------------------------
-//----------------------------------------------------------------------------------------------------------------------
-namespace selene
 {
+    return fcmp_rust::selene_point_to_helios_scalar(point);
+}
 //----------------------------------------------------------------------------------------------------------------------
-SeleneScalar Selene::ed_25519_point_to_scalar(const crypto::ec_point &point) const
+Helios::Point Helios::hash_grow(
+    const Helios::Point &existing_hash,
+    const std::size_t offset,
+    const Helios::Chunk &prior_children,
+    const Helios::Chunk &new_children) const
+{
+    return fcmp_rust::hash_grow_helios(
+        m_generators,
+        existing_hash,
+        offset,
+        prior_children,
+        new_children);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Selene::Point Selene::hash_grow(
+    const Selene::Point &existing_hash,
+    const std::size_t offset,
+    const Selene::Chunk &prior_children,
+    const Selene::Chunk &new_children) const
+{
+    return fcmp_rust::hash_grow_selene(
+        m_generators,
+        existing_hash,
+        offset,
+        prior_children,
+        new_children);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Helios::Scalar Helios::clone(const Helios::Scalar &scalar) const
+{
+    return fcmp_rust::clone_helios_scalar(scalar);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Selene::Scalar Selene::clone(const Selene::Scalar &scalar) const
+{
+    return fcmp_rust::clone_selene_scalar(scalar);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Helios::Point Helios::clone(const Helios::Point &point) const
+{
+    return fcmp_rust::clone_helios_point(point);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Selene::Point Selene::clone(const Selene::Point &point) const
+{
+    return fcmp_rust::clone_selene_point(point);
+}
+//----------------------------------------------------------------------------------------------------------------------
+Helios::Scalar Helios::zero_scalar() const
+{
+    return fcmp_rust::helios_zero_scalar();
+}
+//----------------------------------------------------------------------------------------------------------------------
+Selene::Scalar Selene::zero_scalar() const
+{
+    return fcmp_rust::selene_zero_scalar();
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::array<uint8_t, 32UL> Helios::to_bytes(const Helios::Scalar &scalar) const
+{
+    return fcmp_rust::helios_scalar_to_bytes(scalar);
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::array<uint8_t, 32UL> Selene::to_bytes(const Selene::Scalar &scalar) const
+{
+    return fcmp_rust::selene_scalar_to_bytes(scalar);
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::array<uint8_t, 32UL> Helios::to_bytes(const Helios::Point &point) const
+{
+    return fcmp_rust::helios_point_to_bytes(point);
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::array<uint8_t, 32UL> Selene::to_bytes(const Selene::Point &point) const
+{
+    return fcmp_rust::selene_point_to_bytes(point);
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::string Helios::to_string(const typename Helios::Scalar &scalar) const
+{
+    return epee::string_tools::pod_to_hex(this->to_bytes(scalar));
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::string Selene::to_string(const typename Selene::Scalar &scalar) const
+{
+    return epee::string_tools::pod_to_hex(this->to_bytes(scalar));
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::string Helios::to_string(const typename Helios::Point &point) const
+{
+    return epee::string_tools::pod_to_hex(this->to_bytes(point));
+}
+//----------------------------------------------------------------------------------------------------------------------
+std::string Selene::to_string(const typename Selene::Point &point) const
+{
+    return epee::string_tools::pod_to_hex(this->to_bytes(point));
+}
+//----------------------------------------------------------------------------------------------------------------------
+//----------------------------------------------------------------------------------------------------------------------
+SeleneScalar ed_25519_point_to_scalar(const crypto::ec_point &point)
 {
     static_assert(sizeof(RustEd25519Point) == sizeof(crypto::ec_point),
         "expected same size ed25519 point to rust representation");
@@ -56,15 +153,28 @@ SeleneScalar Selene::ed_25519_point_to_scalar(const crypto::ec_point &point) con
     fcmp::tower_cycle::RustEd25519Point rust_point;
     memcpy(&rust_point, &point, sizeof(fcmp::tower_cycle::RustEd25519Point));
     return fcmp_rust::ed25519_point_to_selene_scalar(rust_point);
-};
+}
 //----------------------------------------------------------------------------------------------------------------------
-HeliosScalar Selene::point_to_cycle_scalar(const Selene::Point &point) const
+Helios::Generators random_helios_generators()
 {
-    return fcmp_rust::selene_point_to_helios_scalar(point);
+    return fcmp_rust::random_helios_generators();
-};
+}
 //----------------------------------------------------------------------------------------------------------------------
-} //namespace selene
+Selene::Generators random_selene_generators()
+{
+    return fcmp_rust::random_selene_generators();
+}
+//----------------------------------------------------------------------------------------------------------------------
+Helios::Point random_helios_hash_init_point()
+{
+    return fcmp_rust::random_helios_hash_init_point();
+}
+//----------------------------------------------------------------------------------------------------------------------
+Selene::Point random_selene_hash_init_point()
+{
+    return fcmp_rust::random_selene_hash_init_point();
+}
 //----------------------------------------------------------------------------------------------------------------------
 //----------------------------------------------------------------------------------------------------------------------
-} //namespace curves
+} //namespace tower_cycle
 } //namespace fcmp

src/fcmp/tower_cycle.h

@@ -31,7 +31,6 @@
 #include "crypto/crypto.h"
 #include "fcmp_rust/cxx.h"
 #include "fcmp_rust/fcmp_rust.h"
-#include "string_tools.h"
 
 #include <string>
 
@@ -41,119 +40,162 @@ namespace tower_cycle
 {
 //----------------------------------------------------------------------------------------------------------------------
 //----------------------------------------------------------------------------------------------------------------------
+// Rust types
+//----------------------------------------------------------------------------------------------------------------------
 using RustEd25519Point = std::array<uint8_t, 32UL>;
 
 // Need to forward declare Scalar types for point_to_cycle_scalar below
 using SeleneScalar = rust::Box<fcmp_rust::SeleneScalar>;
 using HeliosScalar = rust::Box<fcmp_rust::HeliosScalar>;
 //----------------------------------------------------------------------------------------------------------------------
-//----------------------------------------------------------------------------------------------------------------------
+struct HeliosT final
-namespace helios
 {
+    using Generators  = rust::Box<fcmp_rust::HeliosGenerators>;
+    using Scalar      = HeliosScalar;
+    using Point       = rust::Box<fcmp_rust::HeliosPoint>;
+    using Chunk       = rust::Slice<const Scalar>;
+    using CycleScalar = SeleneScalar;
+};
 //----------------------------------------------------------------------------------------------------------------------
-//----------------------------------------------------------------------------------------------------------------------
+struct SeleneT final
-// TODO: Curve classes that inherit from a parent
-static struct Helios final
 {
-    using Generators = rust::Box<fcmp_rust::HeliosGenerators>;
+    using Generators  = rust::Box<fcmp_rust::SeleneGenerators>;
-    using Scalar     = HeliosScalar;
+    using Scalar      = SeleneScalar;
-    using Point      = rust::Box<fcmp_rust::HeliosPoint>;
+    using Point       = rust::Box<fcmp_rust::SelenePoint>;
-    using Chunk      = rust::Slice<const Scalar>;
+    using Chunk       = rust::Slice<const Scalar>;
+    using CycleScalar = HeliosScalar;
+};
+//----------------------------------------------------------------------------------------------------------------------
+//----------------------------------------------------------------------------------------------------------------------
+// Parent curve class that curves in a curve cycle must implement
+//----------------------------------------------------------------------------------------------------------------------
+template<typename C>
+class Curve
+{
+//constructor
+public:
+    Curve(const typename C::Generators &generators, const typename C::Point &hash_init_point):
+        m_generators{generators},
+        m_hash_init_point{hash_init_point}
+    {};
 
-    // TODO: static constants
+//member functions
-    const Generators GENERATORS = fcmp_rust::random_helios_generators();
+public:
-    const Point HASH_INIT_POINT = fcmp_rust::random_helios_hash_init_point();
+    // Read the x-coordinate from this curve's point to get this curve's cycle scalar
+    virtual typename C::CycleScalar point_to_cycle_scalar(const typename C::Point &point) const = 0;
 
-    // Helios point x-coordinates are Selene scalars
+    virtual typename C::Point hash_grow(
-    SeleneScalar point_to_cycle_scalar(const Point &point) const;
+        const typename C::Point &existing_hash,
+        const std::size_t offset,
+        const typename C::Chunk &prior_children,
+        const typename C::Chunk &new_children) const = 0;
+
+    virtual typename C::Scalar clone(const typename C::Scalar &scalar) const = 0;
+    virtual typename C::Point clone(const typename C::Point &point) const = 0;
+
+    virtual typename C::Scalar zero_scalar() const = 0;
+
+    virtual std::array<uint8_t, 32UL> to_bytes(const typename C::Scalar &scalar) const = 0;
+    virtual std::array<uint8_t, 32UL> to_bytes(const typename C::Point &point) const = 0;
+
+    virtual std::string to_string(const typename C::Scalar &scalar) const = 0;
+    virtual std::string to_string(const typename C::Point &point) const = 0;
+
+//member variables
+public:
+    // TODO: make these static constants
+    const typename C::Generators &m_generators;
+    const typename C::Point &m_hash_init_point;
+};
+//----------------------------------------------------------------------------------------------------------------------
+class Helios final : public Curve<HeliosT>
+{
+//typedefs
+public:
+    using Generators  = HeliosT::Generators;
+    using Scalar      = HeliosT::Scalar;
+    using Point       = HeliosT::Point;
+    using Chunk       = HeliosT::Chunk;
+    using CycleScalar = HeliosT::CycleScalar;
+
+//constructor
+public:
+    Helios(const Generators &generators, const Point &hash_init_point)
+    : Curve<HeliosT>(generators, hash_init_point)
+    {};
+
+//member functions
+public:
+    CycleScalar point_to_cycle_scalar(const Point &point) const override;
 
     Point hash_grow(
-        const Generators &generators,
         const Point &existing_hash,
         const std::size_t offset,
         const Chunk &prior_children,
-        const Chunk &new_children) const
+        const Chunk &new_children) const override;
-    {
-        return fcmp_rust::hash_grow_helios(
-            generators,
-            existing_hash,
-            offset,
-            prior_children,
-            new_children);
-    }
 
-    Scalar clone(const Scalar &scalar) const { return fcmp_rust::clone_helios_scalar(scalar); }
+    Scalar clone(const Scalar &scalar) const override;
-    Point clone(const Point &point) const { return fcmp_rust::clone_helios_point(point); }
+    Point clone(const Point &point) const override;
 
-    Scalar zero_scalar() const { return fcmp_rust::helios_zero_scalar(); }
+    Scalar zero_scalar() const override;
 
-    std::array<uint8_t, 32UL> to_bytes(const Scalar &scalar) const
+    std::array<uint8_t, 32UL> to_bytes(const Scalar &scalar) const override;
-        { return fcmp_rust::helios_scalar_to_bytes(scalar); }
+    std::array<uint8_t, 32UL> to_bytes(const Point &point) const override;
-    std::array<uint8_t, 32UL> to_bytes(const Point &point) const
-        { return fcmp_rust::helios_point_to_bytes(point); }
 
-    std::string to_string(const Scalar &scalar) const
+    std::string to_string(const Scalar &scalar) const override;
-        { return epee::string_tools::pod_to_hex(to_bytes(scalar)); }
+    std::string to_string(const Point &point) const override;
-    std::string to_string(const Point &point) const
+};
-        { return epee::string_tools::pod_to_hex(to_bytes(point)); }
-} HELIOS;
-}//namespace helios
 //----------------------------------------------------------------------------------------------------------------------
-//----------------------------------------------------------------------------------------------------------------------
+class Selene final : public Curve<SeleneT>
-namespace selene
 {
-//----------------------------------------------------------------------------------------------------------------------
+//typedefs
-//----------------------------------------------------------------------------------------------------------------------
+public:
-static struct Selene final
+    using Generators  = SeleneT::Generators;
-{
+    using Scalar      = SeleneT::Scalar;
-    using Generators = rust::Box<fcmp_rust::SeleneGenerators>;
+    using Point       = SeleneT::Point;
-    using Scalar     = SeleneScalar;
+    using Chunk       = SeleneT::Chunk;
-    using Point      = rust::Box<fcmp_rust::SelenePoint>;
+    using CycleScalar = SeleneT::CycleScalar;
-    using Chunk      = rust::Slice<const Scalar>;
 
-    // TODO: static constants
+//constructor
-    const Generators GENERATORS = fcmp_rust::random_selene_generators();
+public:
-    const Point HASH_INIT_POINT = fcmp_rust::random_selene_hash_init_point();
+    Selene(const Generators &generators, const Point &hash_init_point)
+    : Curve<SeleneT>(generators, hash_init_point)
+    {};
 
-    // Ed25519 point x-coordinates are Selene scalars
+//member functions
-    SeleneScalar ed_25519_point_to_scalar(const crypto::ec_point &point) const;
+public:
-
+    CycleScalar point_to_cycle_scalar(const Point &point) const override;
-    // Selene point x-coordinates are Helios scalars
-    HeliosScalar point_to_cycle_scalar(const Point &point) const;
 
     Point hash_grow(
-        const Generators &generators,
         const Point &existing_hash,
         const std::size_t offset,
         const Chunk &prior_children,
-        const Chunk &new_children) const
+        const Chunk &new_children) const override;
-    {
-        return fcmp_rust::hash_grow_selene(
-            generators,
-            existing_hash,
-            offset,
-            prior_children,
-            new_children);
-    };
 
-    Scalar clone(const Scalar &scalar) const { return fcmp_rust::clone_selene_scalar(scalar); }
+    Scalar clone(const Scalar &scalar) const override;
-    Point clone(const Point &point) const { return fcmp_rust::clone_selene_point(point); }
+    Point clone(const Point &point) const override;
 
-    Scalar zero_scalar() const { return fcmp_rust::selene_zero_scalar(); }
+    Scalar zero_scalar() const override;
 
-    std::array<uint8_t, 32UL> to_bytes(const Scalar &scalar) const
+    std::array<uint8_t, 32UL> to_bytes(const Scalar &scalar) const override;
-        { return fcmp_rust::selene_scalar_to_bytes(scalar); }
+    std::array<uint8_t, 32UL> to_bytes(const Point &point) const override;
-    std::array<uint8_t, 32UL> to_bytes(const Point &point) const
-        { return fcmp_rust::selene_point_to_bytes(point); }
 
-    std::string to_string(const Scalar &scalar) const
+    std::string to_string(const Scalar &scalar) const override;
-        { return epee::string_tools::pod_to_hex(to_bytes(scalar)); }
+    std::string to_string(const Point &point) const override;
-    std::string to_string(const Point &point) const
+};
-        { return epee::string_tools::pod_to_hex(to_bytes(point)); }
-} SELENE;
-}// namespace selene
 //----------------------------------------------------------------------------------------------------------------------
 //----------------------------------------------------------------------------------------------------------------------
+// Ed25519 point x-coordinates are Selene scalars
+SeleneScalar ed_25519_point_to_scalar(const crypto::ec_point &point);
+//----------------------------------------------------------------------------------------------------------------------
+// TODO: use static constants and get rid of the below functions
+Helios::Generators random_helios_generators();
+Selene::Generators random_selene_generators();
+Helios::Point random_helios_hash_init_point();
+Selene::Point random_selene_hash_init_point();
+//----------------------------------------------------------------------------------------------------------------------
+//----------------------------------------------------------------------------------------------------------------------
+// TODO: implement in cpp file
 template <typename C>
 static void extend_zeroes(const C &curve,
     const std::size_t num_zeroes,
@@ -165,6 +207,7 @@ static void extend_zeroes(const C &curve,
         zeroes_inout.emplace_back(curve.zero_scalar());
 }
 //----------------------------------------------------------------------------------------------------------------------
+// TODO: move impl into cpp
 template <typename C_POINTS, typename C_SCALARS>
 static void extend_scalars_from_cycle_points(const C_POINTS &curve,
     const std::vector<typename C_POINTS::Point> &points,

tests/unit_tests/curve_trees.cpp

@@ -365,10 +365,9 @@ bool CurveTreesUnitTest::validate_tree(const CurveTreesUnitTest::Tree &tree)
         m_curve_trees.m_leaf_layer_chunk_width);
 }
 //----------------------------------------------------------------------------------------------------------------------
-//----------------------------------------------------------------------------------------------------------------------
 // Logging helpers
 //----------------------------------------------------------------------------------------------------------------------
-static void log_last_chunks(const CurveTreesV1::LastChunks &last_chunks)
+void CurveTreesUnitTest::log_last_chunks(const CurveTreesV1::LastChunks &last_chunks)
 {
     const auto &c1_last_chunks = last_chunks.c1_last_chunks;
     const auto &c2_last_chunks = last_chunks.c2_last_chunks;
@@ -388,8 +387,8 @@ static void log_last_chunks(const CurveTreesV1::LastChunks &last_chunks)
             const CurveTreesV1::LastChunkData<Selene> &last_chunk = c2_last_chunks[c2_idx];
 
             MDEBUG("child_offset: "         << last_chunk.child_offset
-                << " , last_child: "        << fcmp::tower_cycle::selene::SELENE.to_string(last_chunk.last_child)
+                << " , last_child: "        << m_curve_trees.m_c2.to_string(last_chunk.last_child)
-                << " , last_parent: "       << fcmp::tower_cycle::selene::SELENE.to_string(last_chunk.last_parent)
+                << " , last_parent: "       << m_curve_trees.m_c2.to_string(last_chunk.last_parent)
                 << " , child_layer_size: "  << last_chunk.child_layer_size
                 << " , parent_layer_size: " << last_chunk.parent_layer_size);
 
@@ -402,8 +401,8 @@ static void log_last_chunks(const CurveTreesV1::LastChunks &last_chunks)
             const CurveTreesV1::LastChunkData<Helios> &last_chunk = c1_last_chunks[c1_idx];
 
             MDEBUG("child_offset: "         << last_chunk.child_offset
-                << " , last_child: "        << fcmp::tower_cycle::helios::HELIOS.to_string(last_chunk.last_child)
+                << " , last_child: "        << m_curve_trees.m_c1.to_string(last_chunk.last_child)
-                << " , last_parent: "       << fcmp::tower_cycle::helios::HELIOS.to_string(last_chunk.last_parent)
+                << " , last_parent: "       << m_curve_trees.m_c1.to_string(last_chunk.last_parent)
                 << " , child_layer_size: "  << last_chunk.child_layer_size
                 << " , parent_layer_size: " << last_chunk.parent_layer_size);
 
@@ -414,7 +413,7 @@ static void log_last_chunks(const CurveTreesV1::LastChunks &last_chunks)
     }
 }
 //----------------------------------------------------------------------------------------------------------------------
-static void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension)
+void CurveTreesUnitTest::log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension)
 {
     const auto &c1_extensions = tree_extension.c1_layer_extensions;
     const auto &c2_extensions = tree_extension.c2_layer_extensions;
@@ -427,9 +426,9 @@ static void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension
     {
         const auto &leaf = tree_extension.leaves.tuples[i];
 
-        const auto O_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.O_x);
+        const auto O_x = m_curve_trees.m_c2.to_string(leaf.O_x);
-        const auto I_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.I_x);
+        const auto I_x = m_curve_trees.m_c2.to_string(leaf.I_x);
-        const auto C_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.C_x);
+        const auto C_x = m_curve_trees.m_c2.to_string(leaf.C_x);
 
         MDEBUG("Leaf idx " << ((i*CurveTreesV1::LEAF_TUPLE_SIZE) + tree_extension.leaves.start_idx)
             << " : { O_x: " << O_x << " , I_x: " << I_x << " , C_x: " << C_x << " }");
@@ -449,7 +448,7 @@ static void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension
 
             for (std::size_t j = 0; j < c2_layer.hashes.size(); ++j)
                 MDEBUG("Hash idx: " << (j + c2_layer.start_idx) << " , hash: "
-                    << fcmp::tower_cycle::selene::SELENE.to_string(c2_layer.hashes[j]));
+                    << m_curve_trees.m_c2.to_string(c2_layer.hashes[j]));
 
             ++c2_idx;
         }
@@ -462,7 +461,7 @@ static void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension
 
             for (std::size_t j = 0; j < c1_layer.hashes.size(); ++j)
                 MDEBUG("Hash idx: " << (j + c1_layer.start_idx) << " , hash: "
-                    << fcmp::tower_cycle::helios::HELIOS.to_string(c1_layer.hashes[j]));
+                    << m_curve_trees.m_c1.to_string(c1_layer.hashes[j]));
 
             ++c1_idx;
         }
@@ -471,7 +470,7 @@ static void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension
     }
 }
 //----------------------------------------------------------------------------------------------------------------------
-static void log_tree(const CurveTreesUnitTest::Tree &tree)
+void CurveTreesUnitTest::log_tree(const CurveTreesUnitTest::Tree &tree)
 {
     MDEBUG("Tree has " << tree.leaves.size() << " leaves, "
         << tree.c1_layers.size() << " helios layers, " <<  tree.c2_layers.size() << " selene layers");
@@ -480,9 +479,9 @@ static void log_tree(const CurveTreesUnitTest::Tree &tree)
     {
         const auto &leaf = tree.leaves[i];
 
-        const auto O_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.O_x);
+        const auto O_x = m_curve_trees.m_c2.to_string(leaf.O_x);
-        const auto I_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.I_x);
+        const auto I_x = m_curve_trees.m_c2.to_string(leaf.I_x);
-        const auto C_x = fcmp::tower_cycle::selene::SELENE.to_string(leaf.C_x);
+        const auto C_x = m_curve_trees.m_c2.to_string(leaf.C_x);
 
         MDEBUG("Leaf idx " << i << " : { O_x: " << O_x << " , I_x: " << I_x << " , C_x: " << C_x << " }");
     }
@@ -500,7 +499,7 @@ static void log_tree(const CurveTreesUnitTest::Tree &tree)
             MDEBUG("Selene layer size: " << c2_layer.size() << " , tree layer: " << i);
 
             for (std::size_t j = 0; j < c2_layer.size(); ++j)
-                MDEBUG("Hash idx: " << j << " , hash: " << fcmp::tower_cycle::selene::SELENE.to_string(c2_layer[j]));
+                MDEBUG("Hash idx: " << j << " , hash: " << m_curve_trees.m_c2.to_string(c2_layer[j]));
 
             ++c2_idx;
         }
@@ -512,7 +511,7 @@ static void log_tree(const CurveTreesUnitTest::Tree &tree)
             MDEBUG("Helios layer size: " << c1_layer.size() << " , tree layer: " << i);
 
             for (std::size_t j = 0; j < c1_layer.size(); ++j)
-                MDEBUG("Hash idx: " << j << " , hash: " << fcmp::tower_cycle::helios::HELIOS.to_string(c1_layer[j]));
+                MDEBUG("Hash idx: " << j << " , hash: " << m_curve_trees.m_c1.to_string(c1_layer[j]));
 
             ++c1_idx;
         }
@@ -524,7 +523,7 @@ static void log_tree(const CurveTreesUnitTest::Tree &tree)
 //----------------------------------------------------------------------------------------------------------------------
 // Test helpers
 //----------------------------------------------------------------------------------------------------------------------
-static const CurveTreesV1::Leaves generate_leaves(const CurveTreesV1 &curve_trees, const std::size_t num_leaves)
+static const CurveTreesV1::Leaves generate_random_leaves(const CurveTreesV1 &curve_trees, const std::size_t num_leaves)
 {
     std::vector<CurveTreesV1::LeafTuple> tuples;
     tuples.reserve(num_leaves);
@@ -553,17 +552,25 @@ static void grow_tree_test(CurveTreesV1 &curve_trees,
     const std::size_t num_leaves,
     CurveTreesUnitTest::Tree &tree_inout)
 {
+    // Get the last chunk from each layer in the tree; empty if tree is empty
     const auto last_chunks = curve_trees_accessor.get_last_chunks(tree_inout);
-    log_last_chunks(last_chunks);
 
+    curve_trees_accessor.log_last_chunks(last_chunks);
+
+    // Get a tree extension object to the existing tree using randomly generated leaves
+    // - The tree extension includes all elements we'll need to add to the existing tree when adding the new leaves
     const auto tree_extension = curve_trees.get_tree_extension(
         last_chunks,
-        generate_leaves(curve_trees, num_leaves));
+        generate_random_leaves(curve_trees, num_leaves));
-    log_tree_extension(tree_extension);
 
+    curve_trees_accessor.log_tree_extension(tree_extension);
+
+    // Use the tree extension to extend the existing tree
     curve_trees_accessor.extend_tree(tree_extension, tree_inout);
-    log_tree(tree_inout);
 
+    curve_trees_accessor.log_tree(tree_inout);
+
+    // Validate tree structure and all hashes
     ASSERT_TRUE(curve_trees_accessor.validate_tree(tree_inout));
 }
 //----------------------------------------------------------------------------------------------------------------------
@@ -572,13 +579,23 @@ static void grow_tree_test(CurveTreesV1 &curve_trees,
 //----------------------------------------------------------------------------------------------------------------------
 TEST(curve_trees, grow_tree)
 {
+    // TODO: use static constant generators and hash init points
+    const Helios::Generators HELIOS_GENERATORS = fcmp::tower_cycle::random_helios_generators();
+    const Selene::Generators SELENE_GENERATORS = fcmp::tower_cycle::random_selene_generators();
+
+    const Helios::Point HELIOS_HASH_INIT_POINT = fcmp::tower_cycle::random_helios_hash_init_point();
+    const Selene::Point SELENE_HASH_INIT_POINT = fcmp::tower_cycle::random_selene_hash_init_point();
+
+    Helios helios(HELIOS_GENERATORS, HELIOS_HASH_INIT_POINT);
+    Selene selene(SELENE_GENERATORS, SELENE_HASH_INIT_POINT);
+
     // TODO: test varying widths
     const std::size_t HELIOS_CHUNK_WIDTH = 5;
     const std::size_t SELENE_CHUNK_WIDTH = 5;
 
     auto curve_trees = CurveTreesV1(
-        fcmp::tower_cycle::helios::HELIOS,
+        helios,
-        fcmp::tower_cycle::selene::SELENE,
+        selene,
         HELIOS_CHUNK_WIDTH,
         SELENE_CHUNK_WIDTH);
 

tests/unit_tests/curve_trees.h

@@ -32,8 +32,8 @@
 #include "fcmp/tower_cycle.h"
 #include "misc_log_ex.h"
 
-using Helios = fcmp::tower_cycle::helios::Helios;
+using Helios = fcmp::tower_cycle::Helios;
-using Selene = fcmp::tower_cycle::selene::Selene;
+using Selene = fcmp::tower_cycle::Selene;
 
 // TODO: make this the instantiation in curve_trees.h/.cpp
 using CurveTreesV1 = fcmp::CurveTrees<Helios, Selene>;
@@ -67,6 +67,11 @@ public:
     // Validate the in-memory tree by re-hashing every layer, starting from root and working down to leaf layer
     bool validate_tree(const Tree &tree);
 
+    // logging helpers
+    void log_last_chunks(const CurveTreesV1::LastChunks &last_chunks);
+    void log_tree_extension(const CurveTreesV1::TreeExtension &tree_extension);
+    void log_tree(const CurveTreesUnitTest::Tree &tree);
+
 //private member functions
 private:
     template<typename C_PARENT>