plonk: in transcript_hasher removed the private buffer variable as an…

… input parameter to the constructor. only the object has access to the buffer now. addresses PR #61 comment #61 (comment)
clearmatics · Oct 26, 2022 · d001bd3 · d001bd3
1 parent c6396cf
commit d001bd3
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Showing 3 changed files with 8 additions and 12 deletions.
diff --git a/libsnark/zk_proof_systems/plonk/srs.hpp b/libsnark/zk_proof_systems/plonk/srs.hpp
@@ -254,7 +254,7 @@ template<typename ppT> class transcript_hasher
 
 public:
     // constructor
-    transcript_hasher(std::vector<uint8_t> &buffer);
+    transcript_hasher();
 
     void add_element(const libff::Fr<ppT> &element);
     void add_element(const libff::G1<ppT> &element);

diff --git a/libsnark/zk_proof_systems/plonk/srs.tcc b/libsnark/zk_proof_systems/plonk/srs.tcc
@@ -73,10 +73,10 @@ plonk_keypair<ppT>::plonk_keypair(
 }
 
 // transcript_hasher constructor
-template<typename ppT>
-transcript_hasher<ppT>::transcript_hasher(std::vector<uint8_t> &buffer)
-    : buffer(std::move(buffer))
+template<typename ppT> transcript_hasher<ppT>::transcript_hasher()
 {
+    // initialize to empty vector
+    this->buffer.clear();
     // test array containing the expected hash values of the communication
     // transcript i.e. the communication challenges (in this order): beta,
     // gamma, alpha, zeta, nu, u WARNING! specific to curve BLS12-381

diff --git a/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp b/libsnark/zk_proof_systems/plonk/tests/test_plonk.cpp
@@ -490,8 +490,7 @@ template<typename ppT> void test_plonk_prover_rounds()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // Prover Round 0 (initialization)
     round_zero_out_t<ppT> round_zero_out = plonk_prover<ppT>::round_zero(srs);
@@ -692,8 +691,7 @@ template<typename ppT> void test_plonk_prover()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;
@@ -970,8 +968,7 @@ template<typename ppT> void test_plonk_verifier_steps()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;
@@ -1075,8 +1072,7 @@ template<typename ppT> void test_plonk_verifier()
     srs<ppT> srs = plonk_srs_derive_from_usrs<ppT>(usrs, circuit);
 
     // initialize hasher
-    std::vector<uint8_t> buffer;
-    transcript_hasher<ppT> hasher(buffer);
+    transcript_hasher<ppT> hasher;
 
     // initialize prover
     plonk_prover<ppT> prover;