ecdsa-sig-formatter - npm Package Compare versions

Comparing version 1.0.1 to 1.0.2

package.json

 {
   "name": "ecdsa-sig-formatter",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "Translate ECDSA signatures between ASN.1/DER and JOSE-style concatenation",
@@ -34,2 +34,3 @@ "main": "src/ecdsa-sig-formatter.js",
   "devDependencies": {
+    "bench": "^0.3.5",
     "chai": "^3.0.0",
@@ -36,0 +37,0 @@ "coveralls": "^2.11.2",

src/ecdsa-sig-formatter.js

 'use strict';
 
 var asn1 = require('asn1.js'),
-	BN = asn1.bignum,
 	base64Url = require('base64-url').escape;
@@ -14,2 +13,5 @@
 
+var seq = 0x10,
+	int = 0x02;
+
 function getParamSize (keySize) {
@@ -35,7 +37,2 @@ var result = ((keySize / 8) | 0) + (keySize % 8 === 0 ? 0 : 1);
 
-function bufToBignum (buf) {
-	var bn = new BN(buf, 10, 'be').iabs();
-	return bn;
-}
-
 function bignumToBuf (bn, numBytes) {
@@ -72,2 +69,30 @@ var buf = new Buffer(bn.toString('hex', numBytes), 'hex');
 
+function reduceBuffer (buf) {
+	var padding = 0;
+	for (var n = buf.length; padding < n && buf[padding] === 0;) {
+		++padding;
+	}
+
+	var needsSign = buf[padding] >= 0x80;
+	if (needsSign) {
+		--padding;
+
+		if (padding < 0) {
+			var old = buf;
+			buf = new Buffer(1 + buf.length);
+			buf[0] = 0;
+			old.copy(buf, 1);
+
+			return buf;
+		}
+	}
+
+	if (padding === 0) {
+		return buf;
+	}
+
+	buf = buf.slice(padding);
+	return buf;
+}
+
 function joseToDer(signature, alg) {
@@ -82,12 +107,27 @@ signature = signatureAsBuffer(signature);
 
-	var r = signature.slice(0, paramBytes);
-	r = bufToBignum(r);
-	var s = signature.slice(paramBytes);
-	s = bufToBignum(s);
+	var r = reduceBuffer(signature.slice(0, paramBytes));
+	var s = reduceBuffer(signature.slice(paramBytes));
 
-	signature = ECDSASigValue.encode({
-		r: r,
-		s: s
-	}, 'der');
+	var rsBytes = 1 + 1 + r.length + 1 + 1 + s.length;
 
+	var oneByteLength = rsBytes < 0x80;
+
+	signature = new Buffer((oneByteLength ? 2 : 3) + rsBytes);
+
+	var offset = 0;
+	signature[offset++] = (seq | 0x20) | 0 << 6;
+	if (oneByteLength) {
+		signature[offset++] = rsBytes;
+	} else {
+		signature[offset++] = 0x80 | 1;
+		signature[offset++] = rsBytes & 0xff;
+	}
+	signature[offset++] = int | (0 << 6);
+	signature[offset++] = r.length;
+	r.copy(signature, offset);
+	offset += r.length;
+	signature[offset++] = int | (0 << 6);
+	signature[offset++] = s.length;
+	s.copy(signature, offset);
+
 	return signature;
@@ -94,0 +134,0 @@ }

No alert changes

Improved metrics

Total package byte prevSize

18808

increased by14.82%

Number of package files

6

increased by50%

Lines of code

139

increased by87.84%

Worsened metrics

Dev dependency count

5

increased by25%

No dependency changes