added pvk->pbk circuit

Combined small fixes

calcpedersenbases/calcpedersenbases.js

@@ -1,14 +1,15 @@
 const bn128 = require("snarkjs").bn128;
 const bigInt = require("snarkjs").bigInt;
 const createBlakeHash = require("blake-hash");
-const assert = require("assert");
 const babyJub = require("../src/babyjub");
 
 function getPoint(S) {
     const F = bn128.Fr;
     const h = createBlakeHash("blake256").update(S).digest();
 
-    assert(h.length == 32);
+    if (h.length != 32) {
+        throw new Error("Invalid length")
+    }
 
     let sign = false;
     if (h[31] & 0x80) {
@@ -52,7 +53,9 @@ function generatePoint(S) {
         p = getPoint(S+"_"+sidx);
         idx++;
     }
-    assert(babyJub.inCurve(p), "Point not in curve");
+    if (!babyJub.inCurve(p)){
+        throw new Error("Point not in curve");
+    }
     return p;
 }
 

circuits/babyjub.circom

@@ -17,6 +17,9 @@
     along with circom. If not, see <https://www.gnu.org/licenses/>.
 */
 
+include "bitify.circom";
+include "escalarmulfix.circom";
+
 template BabyAdd() {
     signal input x1;
     signal input y1;
@@ -77,3 +80,27 @@ template BabyCheck() {
 
     a*x2 + y2 === 1 + d*x2*y2;
 }
+
+// Extracts the public key from private key
+template BabyPbk() {
+    signal private input  in;
+    signal         output Ax;
+    signal         output Ay;
+
+    var BASE8 = [
+        17777552123799933955779906779655732241715742912184938656739573121738514868268,
+        2626589144620713026669568689430873010625803728049924121243784502389097019475
+    ];
+
+    component pvkBits = Num2Bits(253);
+    pvkBits.in <== in;
+
+    component mulFix = EscalarMulFix(253, BASE8);
+
+    var i;
+    for (i=0; i<253; i++) {
+        mulFix.e[i] <== pvkBits.out[i];
+    }
+    Ax  <== mulFix.out[0];
+    Ay  <== mulFix.out[1];
+}

index.js

@@ -1,3 +1,4 @@
 exports.smt = require("./src/smt");
 exports.eddsa = require("./src/eddsa");
 exports.mimc7 = require("./src/mimc7");
+exports.babyJub = require("./src/babyjub");

package.json

@@ -1,6 +1,6 @@
 {
   "name": "circomlib",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "description": "Basic circuits library for Circom",
   "main": "index.js",
   "directories": {
@@ -25,7 +25,8 @@
   "license": "GPL-3.0",
   "dependencies": {
     "blake-hash": "^1.1.0",
-    "snarkjs": "0.1.9",
+    "snarkjs": "0.1.11",
+    "typedarray-to-buffer": "^3.1.5",
     "web3": "^1.0.0-beta.36"
   },
   "devDependencies": {

src/eddsa.js

@@ -3,9 +3,7 @@ const bigInt = require("snarkjs").bigInt;
 const babyJub = require("./babyjub");
 const pedersenHash = require("./pedersenHash").hash;
 const mimc7 = require("./mimc7");
-const crypto = require("crypto");
-
-exports.cratePrvKey = cratePrvKey;
+    
 exports.prv2pub= prv2pub;
 exports.sign = sign;
 exports.signMiMC = signMiMC;
@@ -13,12 +11,9 @@ exports.verify = verify;
 exports.verifyMiMC = verifyMiMC;
 exports.packSignature = packSignature;
 exports.unpackSignature = unpackSignature;
+exports.pruneBuffer = pruneBuffer;
 
 
-function cratePrvKey() {
-    return crypto.randomBytes(32);
-}
-
 function pruneBuffer(_buff) {
     const buff = Buffer.from(_buff);
     buff[0] = buff[0] & 0xF8;

src/evmasm.js

@@ -3,8 +3,7 @@
 //
 
 
-const Web3 = require("web3");
-const assert = require("assert");
+const Web3Utils = require("web3-utils");
 
 class Contract {
     constructor() {
@@ -39,7 +38,7 @@ class Contract {
             genLoadedLength = C.code.length;
         }
 
-        return Web3.utils.bytesToHex(C.code.concat(this.code));
+        return Web3Utils.bytesToHex(C.code.concat(this.code));
     }
 
     stop() { this.code.push(0x00); }
@@ -141,7 +140,9 @@ class Contract {
     msize()  { this.code.push(0x59); }
     gas()  { this.code.push(0x5a); }
     label(name)  {
-        assert(typeof this.labels[name] == "undefined", "Label already defined");
+        if (typeof this.labels[name] != "undefined") {
+            throw new Error("Label already defined");
+        }
         this.labels[name] = this.code.length;
         this.code.push(0x5b);
 
@@ -149,21 +150,24 @@ class Contract {
     }
 
     push(data) {
-        const d = Web3.utils.hexToBytes(Web3.utils.toHex(data));
-        assert(d.length>0);
-        assert(d.length<=32);
+        const d = Web3Utils.hexToBytes(Web3Utils.toHex(data));
+        if (d.length == 0 || d.length > 32) {
+            throw new Error("Assertion failed");
+        }
         this.code = this.code.concat([0x5F + d.length], d);
     }
 
     dup(n) {
-        assert(n>=0);
-        assert(n<16);
+        if (n < 0 || n >= 16) {
+            throw new Error("Assertion failed");
+        }
         this.code.push(0x80 + n);
     }
 
     swap(n) {
-        assert(n>=1);
-        assert(n<=16);
+        if (n < 1 || n > 16) {
+            throw new Error("Assertion failed");
+        }
         this.code.push(0x8f + n);
     }
 

src/mimc7.js

@@ -1,6 +1,6 @@
 const bn128 = require("snarkjs").bn128;
 const bigInt = require("snarkjs").bigInt;
-const Web3 = require("web3");
+const Web3Utils = require("web3-utils");
 const F = bn128.Fr;
 
 const SEED = "mimc";
@@ -8,8 +8,8 @@ const NROUNDS = 91;
 
 exports.getIV = (seed) => {
     if (typeof seed === "undefined") seed = SEED;
-    const c = Web3.utils.keccak256(seed+"_iv");
-    const cn = bigInt(Web3.utils.toBN(c).toString());
+    const c = Web3Utils.keccak256(seed+"_iv");
+    const cn = bigInt(Web3Utils.toBN(c).toString());
     const iv = cn.mod(F.q);
     return iv;
 };
@@ -18,13 +18,13 @@ exports.getConstants = (seed, nRounds) => {
     if (typeof seed === "undefined") seed = SEED;
     if (typeof nRounds === "undefined") nRounds = NROUNDS;
     const cts = new Array(nRounds);
-    let c = Web3.utils.keccak256(SEED);
+    let c = Web3Utils.keccak256(SEED);
     for (let i=1; i<nRounds; i++) {
-        c = Web3.utils.keccak256(c);
+        c = Web3Utils.keccak256(c);
 
-        const n1 = Web3.utils.toBN(c).mod(Web3.utils.toBN(F.q.toString()));
-        const c2 = Web3.utils.padLeft(Web3.utils.toHex(n1), 64);
-        cts[i] = bigInt(Web3.utils.toBN(c2).toString());
+        const n1 = Web3Utils.toBN(c).mod(Web3Utils.toBN(F.q.toString()));
+        const c2 = Web3Utils.padLeft(Web3Utils.toHex(n1), 64);
+        cts[i] = bigInt(Web3Utils.toBN(c2).toString());
     }
     cts[0] = bigInt(0);
     return cts;

src/mimc_gencontract.js

@@ -2,13 +2,13 @@
 // License: LGPL-3.0+
 //
 
-const Web3 = require("web3");
+const Web3Utils = require("web3-utils");
 
 const Contract = require("./evmasm");
 
 function createCode(seed, n) {
 
-    let ci = Web3.utils.keccak256(seed);
+    let ci = Web3Utils.keccak256(seed);
 
     const C = new Contract();
 
@@ -51,7 +51,7 @@ function createCode(seed, n) {
     C.mulmod();         // r=t^7 k q
 
     for (let i=0; i<n-1; i++) {
-        ci = Web3.utils.keccak256(ci);
+        ci = Web3Utils.keccak256(ci);
         C.dup(2);       // q r k q
         C.dup(0);       // q q r k q
         C.dup(0);       // q q q r k q

src/pedersenHash.js

@@ -1,7 +1,6 @@
 const bn128 = require("snarkjs").bn128;
 const bigInt = require("snarkjs").bigInt;
 const babyJub = require("./babyjub");
-const assert = require("assert");
 const createBlakeHash = require("blake-hash");
 
 const GENPOINT_PREFIX = "PedersenGenerator";
@@ -73,7 +72,9 @@ function getBasePoint(pointIdx) {
 
     const p8 = babyJub.mulPointEscalar(p, 8);
 
-    assert(babyJub.inSubgroup(p8), "Point not in curve");
+    if (!babyJub.inSubgroup(p8)) {
+        throw new Error("Point not in curve");
+    }
 
     bases[pointIdx] = p8;
     return p8;

test/babyjub.js

@@ -3,10 +3,12 @@ const path = require("path");
 const snarkjs = require("snarkjs");
 const compiler = require("circom");
 
+const createBlakeHash = require("blake-hash");
+const eddsa = require("../src/eddsa.js");
+
 const assert = chai.assert;
 
-const bigInt = require("big-integer");
-
+const bigInt = require("snarkjs").bigInt;
 
 describe("Baby Jub test", function () {
     let circuitAdd;
@@ -22,6 +24,11 @@ describe("Baby Jub test", function () {
         const cirDefTest = await compiler(path.join(__dirname, "circuits", "babycheck_test.circom"));
         circuitTest = new snarkjs.Circuit(cirDefTest);
         console.log("NConstrains BabyTest: " + circuitTest.nConstraints);
+
+        const cirDefPbk = await compiler(path.join(__dirname, "circuits", "babypbk_test.circom"));
+        circuitPbk = new snarkjs.Circuit(cirDefPbk);
+        console.log("NConstrains BabyPbk: " + circuitPbk.nConstraints);
+
     });
 
     it("Should add point (0,1) and (0,1)", async () => {
@@ -97,4 +104,22 @@ describe("Baby Jub test", function () {
         }
     });
 
+    it("Should extract the public key from the private one", async () => {    
+
+        const rawpvk = Buffer.from("0001020304050607080900010203040506070809000102030405060708090021", "hex");
+        const pvk    = eddsa.pruneBuffer(createBlakeHash("blake512").update(rawpvk).digest().slice(0,32));
+        const S      = bigInt.leBuff2int(pvk).shr(3);
+
+        const A      = eddsa.prv2pub(rawpvk);
+
+        const input = {
+            in : S,
+            Ax : A[0],
+            Ay : A[1]
+        }
+
+        const w = circuitPbk.calculateWitness(input);
+        assert(circuitPbk.checkWitness(w));
+    });
+
 });

test/circuits/babypbk_test.circom

@@ -0,0 +1,3 @@
+include "../../circuits/babyjub.circom";
+
+component main = BabyPbk();

test/eddsa.js

@@ -2,6 +2,7 @@ const chai = require("chai");
 const path = require("path");
 const snarkjs = require("snarkjs");
 const compiler = require("circom");
+// const crypto = require("crypto");
 
 const eddsa = require("../src/eddsa.js");
 const babyJub = require("../src/babyjub.js");
@@ -45,7 +46,7 @@ describe("EdDSA test", function () {
     it("Sign a single 10 bytes from 0 to 9", async () => {
         const msg = Buffer.from("00010203040506070809", "hex");
 
-//        const prvKey = eddsa.cratePrvKey();
+//        const prvKey = crypto.randomBytes(32);
 
         const prvKey = Buffer.from("0001020304050607080900010203040506070809000102030405060708090001", "hex");