Added a proper private input extractor.

.github/workflows/run_tests.yml

@@ -80,6 +80,7 @@ jobs:
             blueprint_verifiers_placeholder_gate_component_test,
             blueprint_proxy_test
             blueprint_mock_mocked_components_test
+            blueprint_private_input_extractor_test
           ]  # Tests to execute
         include: # Abused to enable proof generation for some tests; add more as needed
           - target: blueprint_algebra_fields_plonk_non_native_logic_ops_test

include/nil/blueprint/private_input_extractor.hpp

@@ -0,0 +1,90 @@
+//---------------------------------------------------------------------------//
+// Copyright (c) 2023 Dmitrii Tabalin <[email protected]>
+//
+// MIT License
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//---------------------------------------------------------------------------//
+
+#ifndef CRYPTO3_BLUEPRINT_PRIVATE_INPUT_EXTRACTOR_HPP
+#define CRYPTO3_BLUEPRINT_PRIVATE_INPUT_EXTRACTOR_HPP
+
+#include <unordered_map>
+#include <unordered_set>
+
+#include <nil/blueprint/blueprint/plonk/assignment.hpp>
+#include <nil/blueprint/blueprint/plonk/circuit.hpp>
+#include <nil/crypto3/zk/snark/arithmetization/plonk/variable.hpp>
+
+namespace nil {
+    namespace blueprint {
+        // So you want to figure out where a variable you pass into the component actually gets assigned to?
+        // Congratulations! You've come to the right place. You can do that in just 5 easy steps!
+        // Note that step 2 and 5 are IMPORTANT, and you SHOULD read them!
+        // Step 1: Instantiate your component.
+        // Step 2: Fill the input variables you want to assign to with distinct variables.
+        //         IMPORTANT: the variables you want to assign to MUST be distinct from all others!
+        //                    They also MUST be outside of the component!
+        //                    ENSURE that they are not the same as the default variable (var(0, 0, false, witness)),
+        //                    (or fill all of the input values)
+        //                    E.g. you could make the variable to have very large witness column number.
+        //                    The variable CANNOT be with the legacy private input index: copy constraints
+        //                    would not generate for it and it would not be found.
+        // Step 3: Call input_assignment_variables with the component, the input and the row at which the component
+        //         is going to be based.
+        // Step 4: The map you got in return maps the variables from instance_input to the variables from the
+        //         component.
+        // Step 5: IMPORTANT! Be sure to check that the variable is in the map before assinging to it.
+        //         In rare situations the variable might turn out to be unused.
+        //         The map would not contain the variable in this case.
+        template<typename BlueprintFieldType, typename ComponentType>
+        std::unordered_map<
+            crypto3::zk::snark::plonk_variable<typename BlueprintFieldType::value_type>,
+            crypto3::zk::snark::plonk_variable<typename BlueprintFieldType::value_type>> input_assignment_variables(
+                const ComponentType &component,
+                const crypto3::zk::snark::plonk_table_description<BlueprintFieldType> &desc,
+                typename ComponentType::input_type instance_input,
+                const std::size_t start_row_index) {
+
+            using constraint_system = crypto3::zk::snark::plonk_constraint_system<BlueprintFieldType>;
+            using var = crypto3::zk::snark::plonk_variable<typename BlueprintFieldType::value_type>;
+
+            circuit<constraint_system> bp;
+            assignment<constraint_system> assignment(desc);
+            generate_copy_constraints(component, bp, assignment, instance_input, start_row_index);
+            auto input_vars = instance_input.all_vars();
+            std::unordered_set<var> input_vars_set(input_vars.begin(), input_vars.end());
+
+            std::unordered_map<var, var> result;
+            for (const auto &copy_constraint : bp.copy_constraints()) {
+                auto &var1 = copy_constraint.first,
+                     &var2 = copy_constraint.second;
+                if (input_vars_set.find(var1) != input_vars_set.end()) {
+                    result[var1] = var2;
+                }
+                if (input_vars_set.find(var2) != input_vars_set.end()) {
+                    result[var2] = var1;
+                }
+            }
+            return result;
+        }
+    }   // namespace blueprint
+}   // namespace nil
+
+#endif   // CRYPTO3_BLUEPRINT_PRIVATE_INPUT_EXTRACTOR_HPP

test/CMakeLists.txt

@@ -56,6 +56,7 @@ set(COMMON_TEST_FILES
     "gate_id"
     "utils/connectedness_check"
     "private_input"
+    "private_input_extractor"
     "proxy"
     "mock/mocked_components"
     )

test/private_input_extractor.cpp

@@ -0,0 +1,74 @@
+//---------------------------------------------------------------------------//
+// Copyright (c) 2023 Dmitrii Tabalin <[email protected]>
+//
+// MIT License
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//---------------------------------------------------------------------------//
+
+#define BOOST_TEST_MODULE blueprint_private_input_extractor_test
+
+#include <boost/test/unit_test.hpp>
+
+#include <nil/crypto3/algebra/fields/arithmetic_params/pallas.hpp>
+
+#include <nil/crypto3/hash/keccak.hpp>
+#include <nil/crypto3/random/algebraic_engine.hpp>
+
+#include <nil/blueprint/blueprint/plonk/assignment.hpp>
+#include <nil/blueprint/blueprint/plonk/circuit.hpp>
+#include <nil/blueprint/components/algebra/fields/plonk/addition.hpp>
+
+#include <nil/blueprint/private_input_extractor.hpp>
+
+#include "test_plonk_component.hpp"
+
+using namespace nil;
+
+
+BOOST_AUTO_TEST_CASE(blueprint_plonk_private_input_test) {
+    using field_type = typename crypto3::algebra::curves::pallas::base_field_type;
+    constexpr std::size_t WitnessColumns = 3;
+    constexpr std::size_t PublicInputColumns = 1;
+    constexpr std::size_t ConstantColumns = 0;
+    constexpr std::size_t SelectorColumns = 1;
+    using ArithmetizationType = crypto3::zk::snark::plonk_constraint_system<field_type>;
+    zk::snark::plonk_table_description<field_type> desc(
+        WitnessColumns, PublicInputColumns, ConstantColumns, SelectorColumns);
+
+    using var = crypto3::zk::snark::plonk_variable<typename field_type::value_type>;
+
+    using component_type = blueprint::components::addition<ArithmetizationType, field_type,
+                                                           nil::blueprint::basic_non_native_policy<field_type>>;
+
+    typename component_type::input_type instance_input = {
+        var(0, 0, false, var::column_type::public_input),
+        var(0, 1, false, var::column_type::public_input)
+    };
+
+    component_type component_instance({0, 1, 2}, {}, {});
+
+    auto unopt = nil::blueprint::input_assignment_variables<field_type, component_type>(
+        component_instance, desc, instance_input, 3);
+    BOOST_ASSERT(unopt.size() == 2);
+    BOOST_ASSERT(unopt.count(instance_input.x) == 1);
+    BOOST_ASSERT(unopt.count(instance_input.y) == 1);
+    BOOST_ASSERT(unopt[instance_input.x] == var(0, 3, false, var::column_type::witness));
+    BOOST_ASSERT(unopt[instance_input.y] == var(1, 3, false, var::column_type::witness));
+}