unit_tests: add ge_triple_scalarmult_base_vartime test

tests/unit_tests/multiexp.cpp

@@ -252,3 +252,65 @@ TEST(multiexp, pippenger_cached)
     ASSERT_TRUE(basic(data) == pippenger(data, cache));
   }
 }
+
+TEST(multiexp, scalarmult_triple)
+{
+  std::vector<rct::MultiexpData> data;
+  ge_p2 p2;
+  rct::key res;
+  ge_p3 Gp3;
+
+  ge_frombytes_vartime(&Gp3, rct::G.bytes);
+
+  static const rct::key scalars[] = {
+    rct::Z,
+    rct::I,
+    rct::L,
+    rct::EIGHT,
+    rct::INV_EIGHT,
+  };
+  static const ge_p3 points[] = {
+    ge_p3_identity,
+    ge_p3_H,
+    Gp3,
+  };
+  ge_dsmp ppre[sizeof(points) / sizeof(points[0])];
+
+  for (size_t i = 0; i < sizeof(points) / sizeof(points[0]); ++i)
+    ge_dsm_precomp(ppre[i], &points[i]);
+
+  data.resize(3);
+  for (const rct::key &x: scalars)
+  {
+    data[0].scalar = x;
+    for (const rct::key &y: scalars)
+    {
+      data[1].scalar = y;
+      for (const rct::key &z: scalars)
+      {
+        data[2].scalar = z;
+        for (size_t i = 0; i < sizeof(points) / sizeof(points[0]); ++i)
+        {
+          data[1].point = points[i];
+          for (size_t j = 0; j < sizeof(points) / sizeof(points[0]); ++j)
+          {
+            data[0].point = Gp3;
+            data[2].point = points[j];
+
+            ge_triple_scalarmult_base_vartime(&p2, data[0].scalar.bytes, data[1].scalar.bytes, ppre[i], data[2].scalar.bytes, ppre[j]);
+            ge_tobytes(res.bytes, &p2);
+            ASSERT_TRUE(basic(data) == res);
+
+            for (size_t k = 0; k < sizeof(points) / sizeof(points[0]); ++k)
+            {
+              data[0].point = points[k];
+              ge_triple_scalarmult_precomp_vartime(&p2, data[0].scalar.bytes, ppre[k], data[1].scalar.bytes, ppre[i], data[2].scalar.bytes, ppre[j]);
+              ge_tobytes(res.bytes, &p2);
+              ASSERT_TRUE(basic(data) == res);
+            }
+          }
+        }
+      }
+    }
+  }
+}