feat(dsl)!: add hash index to pedersen constraint (#436)

* feat(noir): add hash index to pedersen constraint * feat: added pedesen with hash_index in header
AztecProtocol · May 30, 2023 · e0b8804 · e0b8804
1 parent e916f0e
commit e0b8804
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Showing 4 changed files with 20 additions and 1 deletion.
diff --git a/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind.cpp b/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind.cpp
@@ -72,6 +72,18 @@ WASM_EXPORT void pedersen_plookup_commit(uint8_t const* inputs_buffer, uint8_t*
     write(output, pedersen_hash);
 }
 
+WASM_EXPORT void pedersen_plookup_commit_with_hash_index(uint8_t const* inputs_buffer,
+                                                         uint8_t* output,
+                                                         uint32_t hash_index)
+{
+    std::vector<grumpkin::fq> to_compress;
+    read(inputs_buffer, to_compress);
+    grumpkin::g1::affine_element pedersen_hash =
+        crypto::pedersen_commitment::lookup::commit_native(to_compress, hash_index);
+
+    write(output, pedersen_hash);
+}
+
 WASM_EXPORT void pedersen__buffer_to_field(uint8_t const* data, size_t length, uint8_t* r)
 {
     std::vector<uint8_t> to_compress(data, data + length);

diff --git a/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind.hpp b/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind.hpp
@@ -19,6 +19,9 @@ WASM_EXPORT void pedersen__compress_with_hash_index(uint8_t const* inputs_buffer
 
 WASM_EXPORT void pedersen__commit(uint8_t const* inputs_buffer, uint8_t* output);
 WASM_EXPORT void pedersen_plookup_commit(uint8_t const* inputs_buffer, uint8_t* output);
+WASM_EXPORT void pedersen_plookup_commit_with_hash_index(uint8_t const* inputs_buffer,
+                                                         uint8_t* output,
+                                                         uint32_t hash_index);
 
 WASM_EXPORT void pedersen__buffer_to_field(uint8_t const* data, size_t length, uint8_t* r);
 }
diff --git a/cpp/src/barretenberg/dsl/acir_format/pedersen.cpp b/cpp/src/barretenberg/dsl/acir_format/pedersen.cpp
@@ -15,7 +15,7 @@ void create_pedersen_constraint(Composer& composer, const PedersenConstraint& in
     }
 
     // TODO: Does Noir need additive homomorphic Pedersen hash? If so, using plookup version won't help.
-    auto point = stdlib::pedersen_plookup_commitment<Composer>::commit(scalars);
+    auto point = stdlib::pedersen_plookup_commitment<Composer>::commit(scalars, input.hash_index);
 
     composer.assert_equal(point.x.witness_index, input.result_x);
     composer.assert_equal(point.y.witness_index, input.result_y);

diff --git a/cpp/src/barretenberg/dsl/acir_format/pedersen.hpp b/cpp/src/barretenberg/dsl/acir_format/pedersen.hpp
@@ -7,6 +7,8 @@ namespace acir_format {
 // P = xG + bH
 struct PedersenConstraint {
     std::vector<uint32_t> scalars;
+    uint32_t hash_index;
+
     uint32_t result_x;
     uint32_t result_y;
 
@@ -19,6 +21,7 @@ template <typename B> inline void read(B& buf, PedersenConstraint& constraint)
 {
     using serialize::read;
     read(buf, constraint.scalars);
+    read(buf, constraint.hash_index);
     read(buf, constraint.result_x);
     read(buf, constraint.result_y);
 }
@@ -27,6 +30,7 @@ template <typename B> inline void write(B& buf, PedersenConstraint const& constr
 {
     using serialize::write;
     write(buf, constraint.scalars);
+    write(buf, constraint.hash_index);
     write(buf, constraint.result_x);
     write(buf, constraint.result_y);
 }