Move preprocession tools to tools

package.json

@@ -4,7 +4,8 @@
   "description": "Javascript library to work with circomlibç",
   "main": "index.js",
   "scripts": {
-    "test": "mocha"
+    "test": "mocha",
+    "poseidonOptimizeConstants": "node tools/poseidon_optimize_constants.js"
   },
   "repository": {
     "type": "git",

tools/calcpedersenbases.js

@@ -0,0 +1,83 @@
+const bn128 = require("snarkjs").bn128;
+const bigInt = require("snarkjs").bigInt;
+const createBlakeHash = require("blake-hash");
+const babyJub = require("../src/babyjub");
+
+function getPoint(S) {
+    const F = bn128.Fr;
+    const h = createBlakeHash("blake256").update(S).digest();
+
+    if (h.length != 32) {
+        throw new Error("Invalid length")
+    }
+
+    let sign = false;
+    if (h[31] & 0x80) {
+        h[31] = h[31] & 0x7F;
+        sign = true;
+    }
+
+    let y = bigInt(0);
+    for (let i=0; i<32; i++) {
+        y = y.shl(8);
+        y = y.add(bigInt(h[i]));
+    }
+
+    const a = bigInt("168700");
+    const d = bigInt("168696");
+
+    const y2 = F.square(y);
+
+    let x = F.sqrt(F.div(
+        F.sub(F.one, y2),
+        F.sub(a, F.mul(d, y2))));
+
+    if (x == null) return null;
+
+    if (sign) x = F.neg(x);
+
+    const p = [bn128.Fr.affine(x), bn128.Fr.affine(y)];
+
+    const p8 = babyJub.mulPointEscalar(p, 8);
+
+    return p8;
+}
+
+
+function generatePoint(S) {
+    let p= null;
+    let idx = 0;
+    while (p==null) {
+        let sidx = "" + idx;
+        while (sidx.length<16) sidx = "0"+sidx;
+        p = getPoint(S+"_"+sidx);
+        idx++;
+    }
+    if (!babyJub.inCurve(p)){
+        throw new Error("Point not in curve");
+    }
+    return p;
+}
+
+
+
+
+
+const g = [
+    bigInt("5299619240641551281634865583518297030282874472190772894086521144482721001553"),
+    bigInt("16950150798460657717958625567821834550301663161624707787222815936182638968203")];
+
+// Sanity check
+if (!babyJub.inCurve(g)) {
+    throw new Error("Generator not In curve -> Some thing goes wrong...");
+}
+
+for (let i=0; i<25; i++) {
+    let S = "" +i;
+    while (S.length<16) S = "0"+S;
+    const P = generatePoint("Iden3_PedersenGenerator_"+S);
+    console.log(`[${P[0].toString()}, ${P[1].toString()}]`);
+}
+
+
+

tools/poseidon_optimize_constants.js

@@ -25,7 +25,7 @@ function stringifyBigInts(o) {
     }
 }
 
-const { C, M } = unstringifyBigInts(require("./poseidon_constants.json"));
+const { C, M } = unstringifyBigInts(require("../src/poseidon_constants.json"));
 
 const N_ROUNDS_F = 8;
 const N_ROUNDS_P = [56, 57, 56, 60, 60, 63, 64, 63, 60, 66, 60, 65, 70, 60, 64, 68];
@@ -290,7 +290,7 @@ async function run() {
 
     opt = stringifyBigInts(opt);
 
-    fs.writeFileSync(path.join(__dirname, "poseidon_constants_opt.json"), JSON.stringify(opt, null, 1), "utf8");
+    fs.writeFileSync(path.join(__dirname, "..", "src", "poseidon_constants_opt.json"), JSON.stringify(opt, null, 1), "utf8");
 }
 
 run().then(()=> {