use 35 rounds for poseidon hash, update poseidon constants from sage script for 35 rounds

(cherry picked from commit afb4eff954c6a43f3b30c0792459416a26f1cf3f)

circuits/poseidon.circom

@@ -43,10 +43,9 @@ template Poseidon(nInputs) {
     // Using recommended parameters from whitepaper https://eprint.iacr.org/2019/458.pdf (table 2, table 8)
     // Generated by https://extgit.iaik.tugraz.at/krypto/hadeshash/-/blob/master/code/calc_round_numbers.py
     // And rounded up to nearest integer that divides by t
-    var N_ROUNDS_P[8] = [56, 57, 56, 60, 60, 63, 64, 63];
     var t = nInputs + 1;
     var nRoundsF = 8;
-    var nRoundsP = N_ROUNDS_P[t - 2];
+    var nRoundsP = 35;
     var C[t*(nRoundsF + nRoundsP)] = POSEIDON_C(t);
     var M[t][t] = POSEIDON_M(t);
 

src/poseidon.js

@@ -14,22 +14,21 @@ const { C, M } = unstringifyBigInts(require("./poseidon_constants.json"));
 // Generated by https://extgit.iaik.tugraz.at/krypto/hadeshash/-/blob/master/code/calc_round_numbers.py
 // And rounded up to nearest integer that divides by t
 const N_ROUNDS_F = 8;
-const N_ROUNDS_P = [56, 57, 56, 60, 60, 63, 64, 63];
+const N_ROUNDS_P = 35;
 
 const pow5 = a => F.mul(a, F.square(F.square(a, a)));
 
 function poseidon(inputs) {
     assert(inputs.length > 0);
-    assert(inputs.length < N_ROUNDS_P.length - 1);
+    assert(inputs.length < 5);
 
     const t = inputs.length + 1;
     const nRoundsF = N_ROUNDS_F;
-    const nRoundsP = N_ROUNDS_P[t - 2];
+    const nRoundsP = N_ROUNDS_P;
 
     let state = [...inputs.map(a => F.e(a)), F.zero];
     for (let r = 0; r < nRoundsF + nRoundsP; r++) {
-        state = state.map((a, i) => F.add(a, C[t - 2][r * t + i]));
+        state = state.map((a, i) => F.add(a, BigInt(C[t - 2][r * t + i])));
-
         if (r < nRoundsF / 2 || r >= nRoundsF / 2 + nRoundsP) {
             state = state.map(a => pow5(a));
         } else {
@@ -39,7 +38,7 @@ function poseidon(inputs) {
         // no matrix multiplication in the last round
         if (r < nRoundsF + nRoundsP - 1) {
             state = state.map((_, i) =>
-                state.reduce((acc, a, j) => F.add(acc, F.mul(M[t - 2][j][i], a)), F.zero)
+                state.reduce((acc, a, j) => F.add(acc, F.mul(BigInt(M[t - 2][j][i]), a)), F.zero)
             );
         }
     }

src/poseidon_gencontract.js

@@ -9,9 +9,12 @@ const Web3Utils = require("web3-utils");
 const { C:K, M } = unstringifyBigInts(require("./poseidon_constants.json"));
 
 const N_ROUNDS_F = 8;
-const N_ROUNDS_P = [56, 57, 56, 60, 60, 63, 64, 63];
+const N_ROUNDS_P = 35;
 
 function toHex256(a) {
+    if (typeof a === "string" && a.startsWith("0x")) {
+        return a;
+    }
     let S = a.toString(16);
     while (S.length < 64) S="0"+S;
     return "0x" + S;
@@ -19,10 +22,10 @@ function toHex256(a) {
 
 function createCode(nInputs) {
 
-    if (( nInputs<1) || (nInputs>8)) throw new Error("Invalid number of inputs. Must be 1<=nInputs<=8");
+    if (( nInputs<1) || (nInputs>4)) throw new Error("Invalid number of inputs. Must be 1<=nInputs<=8");
     const t = nInputs + 1;
     const nRoundsF = N_ROUNDS_F;
-    const nRoundsP = N_ROUNDS_P[t - 2];
+    const nRoundsP = N_ROUNDS_P;
 
     const C = new Contract();