feat: laying out a new recursion constraint for honk

barretenberg/acir_tests/reset_acir_tests.sh

@@ -0,0 +1,7 @@
+cd ~/aztec-packages/noir/noir-repo
+cargo clean
+noirup -p .
+cd test_programs && ./rebuild.sh
+
+cd ~/aztec-packages/barretenberg/acir_tests
+rm -rf acir_tests

barretenberg/cpp/src/barretenberg/dsl/acir_format/acir_format.cpp

@@ -118,6 +118,7 @@ void build_constraints(Builder& builder, AcirFormat const& constraint_system, bo
         create_bigint_to_le_bytes_constraint(builder, constraint, dsl_bigints);
     }
 
+    // RecursionConstraint
     // TODO(https://github.com/AztecProtocol/barretenberg/issues/817): disable these for UGH for now since we're not yet
     // dealing with proper recursion
     if constexpr (IsGoblinUltraBuilder<Builder>) {
@@ -206,6 +207,120 @@ void build_constraints(Builder& builder, AcirFormat const& constraint_system, bo
             builder.set_recursive_proof(proof_output_witness_indices);
         }
     }
+
+    // HonkRecursionConstraint
+    // TODO(https://github.com/AztecProtocol/barretenberg/issues/817): disable these for UGH for now since we're not yet
+    // dealing with proper recursion
+    if constexpr (IsGoblinUltraBuilder<Builder>) {
+        if (!constraint_system.honk_recursion_constraints.empty()) {
+            info("WARNING: this circuit contains honk_recursion_constraints!");
+        }
+    } else {
+        // These are set and modified whenever we encounter a recursion opcode
+        //
+        // These should not be set by the caller
+        // TODO(maxim): Check if this is always the case. ie I won't receive a proof that will set the first
+        // TODO(maxim): input_aggregation_object to be non-zero.
+        // TODO(maxim): if not, we can add input_aggregation_object to the proof too for all recursive proofs
+        // TODO(maxim): This might be the case for proof trees where the proofs are created on different machines
+        std::array<uint32_t, HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE> current_aggregation_object = {
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+        };
+
+        // Get the size of proof with no public inputs prepended to it
+        // This is used while processing recursion constraints to determine whether
+        // the proof we are verifying contains a recursive proof itself
+        auto proof_size_no_pub_inputs = recursion_honk_proof_size_without_public_inputs();
+
+        // Add recursion constraints
+        for (auto constraint : constraint_system.honk_recursion_constraints) {
+            // A proof passed into the constraint should be stripped of its public inputs, except in the case where a
+            // proof contains an aggregation object itself. We refer to this as the `nested_aggregation_object`. The
+            // verifier circuit requires that the indices to a nested proof aggregation state are a circuit constant.
+            // The user tells us they how they want these constants set by keeping the nested aggregation object
+            // attached to the proof as public inputs. As this is the only object that can prepended to the proof if the
+            // proof is above the expected size (with public inputs stripped)
+            std::array<uint32_t, HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE> nested_aggregation_object = {};
+            // If the proof has public inputs attached to it, we should handle setting the nested aggregation object
+            // The public inputs attached to a proof should match the aggregation object in size
+            if (constraint.proof.size() - proof_size_no_pub_inputs !=
+                HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE) {
+                auto error_string = format(
+                    "Public inputs are always stripped from proofs unless we have a recursive proof.\n"
+                    "Thus, public inputs attached to a proof must match the recursive aggregation object in size "
+                    "which is ",
+                    HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE);
+                throw_or_abort(error_string);
+            }
+            for (size_t i = 0; i < HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE; ++i) {
+                // Set the nested aggregation object indices to the current size of the public inputs
+                // This way we know that the nested aggregation object indices will always be the last
+                // indices of the public inputs
+                nested_aggregation_object[i] = static_cast<uint32_t>(constraint.public_inputs.size());
+                // Attach the nested aggregation object to the end of the public inputs to fill in
+                // the slot where the nested aggregation object index will point into
+                constraint.public_inputs.emplace_back(constraint.proof[i]);
+            }
+            // Remove the aggregation object so that they can be handled as normal public inputs
+            // in they way taht the recursion constraint expects
+            constraint.proof.erase(constraint.proof.begin(),
+                                   constraint.proof.begin() +
+                                       static_cast<std::ptrdiff_t>(HonkRecursionConstraint::AGGREGATION_OBJECT_SIZE));
+            current_aggregation_object = create_honk_recursion_constraints(builder,
+                                                                           constraint,
+                                                                           current_aggregation_object,
+                                                                           nested_aggregation_object,
+                                                                           has_valid_witness_assignments);
+        }
+
+        // Now that the circuit has been completely built, we add the output aggregation as public
+        // inputs.
+        if (!constraint_system.honk_recursion_constraints.empty()) {
+
+            // First add the output aggregation object as public inputs
+            // Set the indices as public inputs because they are no longer being
+            // created in ACIR
+            for (const auto& idx : current_aggregation_object) {
+                builder.set_public_input(idx);
+            }
+
+            // Make sure the verification key records the public input indices of the
+            // final recursion output.
+            std::vector<uint32_t> proof_output_witness_indices(current_aggregation_object.begin(),
+                                                               current_aggregation_object.end());
+            builder.set_recursive_proof(proof_output_witness_indices);
+        } else if (builder.is_recursive_circuit) { // Set a default aggregation object if we don't have one.
+            // TODO(https://github.com/AztecProtocol/barretenberg/issues/911): These are pairing points extracted from
+            // a valid proof. This is a workaround because we can't represent the point at infinity in biggroup yet.
+            fq x0("0x031e97a575e9d05a107acb64952ecab75c020998797da7842ab5d6d1986846cf");
+            fq y0("0x178cbf4206471d722669117f9758a4c410db10a01750aebb5666547acf8bd5a4");
+
+            fq x1("0x0f94656a2ca489889939f81e9c74027fd51009034b3357f0e91b8a11e7842c38");
+            fq y1("0x1b52c2020d7464a0c80c0da527a08193fe27776f50224bd6fb128b46c1ddb67f");
+            std::vector<fq> aggregation_object_fq_values = { x0, y0, x1, y1 };
+            size_t agg_obj_indices_idx = 0;
+            for (fq val : aggregation_object_fq_values) {
+                const uint256_t x = val;
+                std::array<bb::fr, fq_ct::NUM_LIMBS> val_limbs = {
+                    x.slice(0, fq_ct::NUM_LIMB_BITS),
+                    x.slice(fq_ct::NUM_LIMB_BITS, fq_ct::NUM_LIMB_BITS * 2),
+                    x.slice(fq_ct::NUM_LIMB_BITS * 2, fq_ct::NUM_LIMB_BITS * 3),
+                    x.slice(fq_ct::NUM_LIMB_BITS * 3, bb::stdlib::field_conversion::TOTAL_BITS)
+                };
+                for (size_t i = 0; i < fq_ct::NUM_LIMBS; ++i) {
+                    uint32_t idx = builder.add_variable(val_limbs[i]);
+                    builder.set_public_input(idx);
+                    current_aggregation_object[agg_obj_indices_idx] = idx;
+                    agg_obj_indices_idx++;
+                }
+            }
+            // Make sure the verification key records the public input indices of the
+            // final recursion output.
+            std::vector<uint32_t> proof_output_witness_indices(current_aggregation_object.begin(),
+                                                               current_aggregation_object.end());
+            builder.set_recursive_proof(proof_output_witness_indices);
+        }
+    }
 }
 
 /**

barretenberg/cpp/src/barretenberg/dsl/acir_format/acir_format.hpp

@@ -9,6 +9,7 @@
 #include "ec_operations.hpp"
 #include "ecdsa_secp256k1.hpp"
 #include "ecdsa_secp256r1.hpp"
+#include "honk_recursion_constraint.hpp"
 #include "keccak_constraint.hpp"
 #include "logic_constraint.hpp"
 #include "multi_scalar_mul.hpp"
@@ -54,6 +55,7 @@ struct AcirFormat {
     std::vector<MultiScalarMul> multi_scalar_mul_constraints;
     std::vector<EcAdd> ec_add_constraints;
     std::vector<RecursionConstraint> recursion_constraints;
+    std::vector<HonkRecursionConstraint> honk_recursion_constraints;
     std::vector<BigIntFromLeBytes> bigint_from_le_bytes_constraints;
     std::vector<BigIntToLeBytes> bigint_to_le_bytes_constraints;
     std::vector<BigIntOperation> bigint_operations;
@@ -89,6 +91,7 @@ struct AcirFormat {
                    multi_scalar_mul_constraints,
                    ec_add_constraints,
                    recursion_constraints,
+                   honk_recursion_constraints,
                    poly_triple_constraints,
                    block_constraints,
                    bigint_from_le_bytes_constraints,

barretenberg/cpp/src/barretenberg/dsl/acir_format/acir_format.test.cpp

@@ -52,6 +52,7 @@ TEST_F(AcirFormatTests, TestASingleConstraintNoPubInputs)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -170,6 +171,7 @@ TEST_F(AcirFormatTests, TestLogicGateFromNoirCircuit)
                                   .multi_scalar_mul_constraints = {},
                                   .ec_add_constraints = {},
                                   .recursion_constraints = {},
+                                  .honk_recursion_constraints = {},
                                   .bigint_from_le_bytes_constraints = {},
                                   .bigint_to_le_bytes_constraints = {},
                                   .bigint_operations = {},
@@ -240,6 +242,7 @@ TEST_F(AcirFormatTests, TestSchnorrVerifyPass)
                                   .multi_scalar_mul_constraints = {},
                                   .ec_add_constraints = {},
                                   .recursion_constraints = {},
+                                  .honk_recursion_constraints = {},
                                   .bigint_from_le_bytes_constraints = {},
                                   .bigint_to_le_bytes_constraints = {},
                                   .bigint_operations = {},
@@ -337,6 +340,7 @@ TEST_F(AcirFormatTests, TestSchnorrVerifySmallRange)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -453,6 +457,7 @@ TEST_F(AcirFormatTests, TestVarKeccak)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -502,6 +507,7 @@ TEST_F(AcirFormatTests, TestKeccakPermutation)
                                   .multi_scalar_mul_constraints = {},
                                   .ec_add_constraints = {},
                                   .recursion_constraints = {},
+                                  .honk_recursion_constraints = {},
                                   .bigint_from_le_bytes_constraints = {},
                                   .bigint_to_le_bytes_constraints = {},
                                   .bigint_operations = {},

barretenberg/cpp/src/barretenberg/dsl/acir_format/bigint_constraint.test.cpp

@@ -189,6 +189,7 @@ TEST_F(BigIntTests, TestBigIntConstraintMultiple)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -259,6 +260,7 @@ TEST_F(BigIntTests, TestBigIntConstraintSimple)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = { from_le_bytes_constraint_bigint1 },
         .bigint_to_le_bytes_constraints = { result2_to_le_bytes },
         .bigint_operations = { add_constraint },
@@ -314,6 +316,7 @@ TEST_F(BigIntTests, TestBigIntConstraintReuse)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -373,6 +376,7 @@ TEST_F(BigIntTests, TestBigIntConstraintReuse2)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -453,6 +457,7 @@ TEST_F(BigIntTests, TestBigIntDIV)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = { from_le_bytes_constraint_bigint1, from_le_bytes_constraint_bigint2 },
         .bigint_to_le_bytes_constraints = { result3_to_le_bytes },
         .bigint_operations = { div_constraint },

barretenberg/cpp/src/barretenberg/dsl/acir_format/block_constraint.test.cpp

@@ -131,6 +131,7 @@ TEST_F(UltraPlonkRAM, TestBlockConstraint)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},

barretenberg/cpp/src/barretenberg/dsl/acir_format/ec_operations.test.cpp

@@ -76,6 +76,7 @@ TEST_F(EcOperations, TestECOperations)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = { ec_add_constraint },
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},

barretenberg/cpp/src/barretenberg/dsl/acir_format/ecdsa_secp256k1.test.cpp

@@ -111,6 +111,7 @@ TEST_F(ECDSASecp256k1, TestECDSAConstraintSucceed)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -162,6 +163,7 @@ TEST_F(ECDSASecp256k1, TestECDSACompilesForVerifier)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -208,6 +210,7 @@ TEST_F(ECDSASecp256k1, TestECDSAConstraintFail)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},

barretenberg/cpp/src/barretenberg/dsl/acir_format/ecdsa_secp256r1.test.cpp

@@ -145,6 +145,7 @@ TEST(ECDSASecp256r1, test_hardcoded)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -198,6 +199,7 @@ TEST(ECDSASecp256r1, TestECDSAConstraintSucceed)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -249,6 +251,7 @@ TEST(ECDSASecp256r1, TestECDSACompilesForVerifier)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},
@@ -295,6 +298,7 @@ TEST(ECDSASecp256r1, TestECDSAConstraintFail)
         .multi_scalar_mul_constraints = {},
         .ec_add_constraints = {},
         .recursion_constraints = {},
+        .honk_recursion_constraints = {},
         .bigint_from_le_bytes_constraints = {},
         .bigint_to_le_bytes_constraints = {},
         .bigint_operations = {},