Merge pull request #5 from starkbank/feature/postman-compatibility

Feature/postman compatibility

Author: cdottori-stark

ellipticcurve/ecdsa.js

@@ -9,11 +9,16 @@ const randomInteger = Integer.between;
 const modulo = Integer.modulo;
 
 
-exports.sign = function (message, privateKey, hashfunc=sha256) {
+exports.sign = function (message, privateKey, hashfunc = null, randNum = null) {
+    if (hashfunc == null) {
+        hashfunc = sha256;
+    }
     let hashMessage = hashfunc(message);
     let numberMessage = BinaryAscii.numberFromHex(hashMessage);
     let curve = privateKey.curve;
-    let randNum = randomInteger(BigInt(1), curve.N.minus(1));
+    if (randNum == null) {
+        randNum = randomInteger(BigInt(1), curve.N.minus(1));
+    }
     let randSignPoint = EcdsaMath.multiply(curve.G, randNum, curve.N, curve.A, curve.P);
     let r = modulo(randSignPoint.x, curve.N);
     let s = modulo((numberMessage.add(r.multiply(privateKey.secret)).multiply(EcdsaMath.inv(randNum, curve.N))), curve.N);

test/test.js

@@ -1,10 +1,11 @@
-var assert = require("assert");
+const assert = require("assert");
+const BigInt = require("big-integer");
 
-var Ecdsa = require("../ellipticcurve/ecdsa");
-var PrivateKey = require("../ellipticcurve/privateKey").PrivateKey;
-var PublicKey = require("../ellipticcurve/publicKey").PublicKey;
-var Signature = require("../ellipticcurve/signature").Signature;
-var File = require("../ellipticcurve/utils/file");
+const Ecdsa = require("../ellipticcurve/ecdsa");
+const PrivateKey = require("../ellipticcurve/privateKey").PrivateKey;
+const PublicKey = require("../ellipticcurve/publicKey").PublicKey;
+const Signature = require("../ellipticcurve/signature").Signature;
+const File = require("../ellipticcurve/utils/file");
 
 
 describe("ECDSA test", function() {
@@ -152,4 +153,18 @@ describe("Signature test", function() {
             assert.equal(String(signature1.s), String(signature2.s));
         });
     });
+    describe("#testExternalRandNum()", function () {
+        it("should confirm authenticity and same signature", function () {
+            let privateKey = new PrivateKey();
+            let publicKey = privateKey.publicKey();
+            let message = "This is a message";
+            let signature_1 = Ecdsa.sign(message, privateKey, null, BigInt(123));
+            let signature_2 = Ecdsa.sign(message, privateKey, null, BigInt(123));
+
+            assert.equal(Ecdsa.verify(message, signature_1, publicKey), true);
+            assert.equal(Ecdsa.verify(message, signature_2, publicKey), true);
+            assert.equal(signature_1.r.value, signature_2.r.value);
+            assert.equal(signature_1.s.value, signature_2.s.value);
+        });
+    });
 });