From 9fdb56b44c433691f893de87f484641b24ab25c5 Mon Sep 17 00:00:00 2001
From: Gui Iribarren <gui@altermundi.net>
Date: Wed, 29 Nov 2023 14:11:47 +0100
Subject: [PATCH] parametrize circuit PublicSignals (WIP, not yet working)

---
 crypto/zk/circuit/config.go | 12 ++++++++++++
 crypto/zk/utils.go          | 13 +------------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/crypto/zk/circuit/config.go b/crypto/zk/circuit/config.go
index 26af960fd..1f2d51fa9 100644
--- a/crypto/zk/circuit/config.go
+++ b/crypto/zk/circuit/config.go
@@ -37,6 +37,8 @@ type ZkCircuitConfig struct {
 	// FilenameWasm defines the name of the file of the circuit wasm compiled
 	// version
 	WasmFilename string `json:"wasmFilename"` // circuit.wasm
+	// PublicSignals maps public signal indexes to their contents
+	PublicSignals map[int]string
 	// maxCensusSize contains a precomputed max size of a census for the
 	// circuit, which is defined by the expresion:
 	//   maxCensusSize = 2^circuitLevels
@@ -106,6 +108,16 @@ var CircuitsConfigurations = map[string]*ZkCircuitConfig{
 		VerificationKeyFilename: "census_verification_key.json",
 		WasmHash:                hexToBytes("0xc98133cf4d84ced677549e0d848739f4e80ddf78af678cbc8b95377247a92773"),
 		WasmFilename:            "census.wasm",
+		PublicSignals: map[int]string{
+			0: electionId[0],
+			1: electionId[1],
+			2: nullifier,
+			3: voteWeight,
+			4: voteHash[0],
+			5: voteHash[1],
+			6: sikRoot,
+			7: censusRoot,
+		},
 	},
 }
 
diff --git a/crypto/zk/utils.go b/crypto/zk/utils.go
index e70ec1615..4773a8c27 100644
--- a/crypto/zk/utils.go
+++ b/crypto/zk/utils.go
@@ -18,16 +18,6 @@ import (
 // 		A: [3]bigint,
 // 		B: [3][2]bigint,
 // 		C: [3]bigint,
-// 		PublicSignals: [8]bigint{
-//			0: electionId[0],
-// 			1: electionId[1],
-// 			2: nullifier,
-// 			3: voteHash[0],
-// 			4: voteHash[1],
-// 			5: sikRoot,
-// 			6: censusRoot
-// 			7: voteWeight,
-//		}
 // 	}
 
 // Default length of each proof parameters
@@ -36,7 +26,6 @@ const (
 	proofBLen    = 6 // flatted
 	proofBEncLen = 3 // matrix
 	proofCLen    = 3
-	publicSigLen = 8
 )
 
 // bn254BaseField contains the Base Field of the twisted Edwards curve, whose
@@ -88,7 +77,7 @@ func ProverProofToProtobufZKProof(p *prover.Proof, electionId, sikRoot,
 
 	// if public signals are provided, check their format
 	proof.PublicInputs = p.PubSignals
-	if p.PubSignals != nil && len(p.PubSignals) != publicSigLen {
+	if p.PubSignals != nil && len(p.PubSignals) != len(app.TransactionHandler.ZkCircuit().Config.PublicSignals) { // of course this won't work because app is totally out of scope of zk package
 		return nil, fmt.Errorf("wrong ZkSnark prover public signals format")
 	}
 	// if not, check if the rest of the arguments are provided and try to