ecdsa-sig-formatter - npm Package Compare versions

Comparing version 1.0.2 to 1.0.5

package.json

 {
   "name": "ecdsa-sig-formatter",
-  "version": "1.0.2",
+  "version": "1.0.5",
   "description": "Translate ECDSA signatures between ASN.1/DER and JOSE-style concatenation",
   "main": "src/ecdsa-sig-formatter.js",
   "scripts": {
+    "check-style": "eslint .",
+    "pretest": "npm run check-style",
     "test": "istanbul cover --root src _mocha -- spec",
@@ -30,12 +32,15 @@ "report-cov": "cat ./coverage/lcov.info | coveralls"
   "dependencies": {
-    "asn1.js": "^2.0.3",
     "base64-url": "^1.2.1"
   },
   "devDependencies": {
-    "bench": "^0.3.5",
-    "chai": "^3.0.0",
-    "coveralls": "^2.11.2",
-    "istanbul": "^0.3.15",
-    "mocha": "^2.2.5"
+    "bench": "^0.3.6",
+    "chai": "^3.4.1",
+    "coveralls": "^2.11.6",
+    "elliptic": "^6.1.0",
+    "eslint": "^1.10.3",
+    "eslint-config-brightspace": "^0.1.0",
+    "istanbul": "^0.4.2",
+    "jwk-to-pem": "^1.2.4",
+    "mocha": "^2.3.4"
   }
 }

README.md

@@ -61,7 +61,6 @@ # ecdsa-sig-formatter
 
-This repository is configured with [EditorConfig][EditorConfig], [jscs][jscs]
-and [JSHint][JSHint] rules.
+This repository is configured with [EditorConfig][EditorConfig] and
+[ESLint][ESLint] rules.
 
 [EditorConfig]: http://editorconfig.org/
-[jscs]: http://jscs.info/
-[JSHint]: http://jshint.com/
+[ESLint]: http://eslint.org

src/ecdsa-sig-formatter.js

 'use strict';
 
-var asn1 = require('asn1.js'),
-	base64Url = require('base64-url').escape;
+var base64Url = require('base64-url').escape;
 
-var ECDSASigValue = asn1.define('ECDSASigValue', function () {
-	this.seq().obj(
-		this.key('r').int(),
-		this.key('s').int()
-	);
-});
+var getParamBytesForAlg = require('./param-bytes-for-alg');
 
-var seq = 0x10,
-	int = 0x02;
+var MAX_OCTET = 0x80,
+	CLASS_UNIVERSAL = 0,
+	PRIMITIVE_BIT = 0x20,
+	TAG_SEQ = 0x10,
+	TAG_INT = 0x02,
+	ENCODED_TAG_SEQ = (TAG_SEQ | PRIMITIVE_BIT) | (CLASS_UNIVERSAL << 6),
+	ENCODED_TAG_INT = TAG_INT | (CLASS_UNIVERSAL << 6);
 
-function getParamSize (keySize) {
-	var result = ((keySize / 8) | 0) + (keySize % 8 === 0 ? 0 : 1);
-	return result;
-}
-
-var paramBytesForAlg = {
-	ES256: getParamSize(256),
-	ES384: getParamSize(384),
-	ES512: getParamSize(521)
-};
-
-function getParamBytesForAlg (alg) {
-	var paramBytes = paramBytesForAlg[alg];
-	if (paramBytes) {
-		return paramBytes;
-	}
-
-	throw new Error('Unknown algorithm "' + alg + '"');
-}
-
-function bignumToBuf (bn, numBytes) {
-	var buf = new Buffer(bn.toString('hex', numBytes), 'hex');
-	return buf;
-}
-
-function signatureAsBuffer (signature) {
+function signatureAsBuffer(signature) {
 	if (Buffer.isBuffer(signature)) {
-		return new Buffer(signature);
+		return signature;
 	} else if ('string' === typeof signature) {
@@ -55,8 +29,77 @@ return new Buffer(signature, 'base64');
 
-	signature = ECDSASigValue.decode(signature, 'der');
+	// the DER encoded param should at most be the param size, plus a padding
+	// zero, since due to being a signed integer
+	var maxEncodedParamLength = paramBytes + 1;
 
-	var r = bignumToBuf(signature.r, paramBytes);
-	var s = bignumToBuf(signature.s, paramBytes);
+	var inputLength = signature.length;
 
-	signature = Buffer.concat([r, s], r.length + s.length);
+	var offset = 0;
+	if (signature[offset++] !== ENCODED_TAG_SEQ) {
+		throw new Error('Could not find expected "seq"');
+	}
+
+	var seqLength = signature[offset++];
+	if (seqLength === (MAX_OCTET | 1)) {
+		seqLength = signature[offset++];
+	}
+
+	if (inputLength - offset < seqLength) {
+		throw new Error('"seq" specified length of "' + seqLength + '", only "' + (inputLength - offset) + '" remaining');
+	}
+
+	if (signature[offset++] !== ENCODED_TAG_INT) {
+		throw new Error('Could not find expected "int" for "r"');
+	}
+
+	var rLength = signature[offset++];
+
+	if (inputLength - offset - 2 < rLength) {
+		throw new Error('"r" specified length of "' + rLength + '", only "' + (inputLength - offset - 2) + '" available');
+	}
+
+	if (maxEncodedParamLength < rLength) {
+		throw new Error('"r" specified length of "' + rLength + '", max of "' + maxEncodedParamLength + '" is acceptable');
+	}
+
+	var r = signature.slice(offset, offset + rLength);
+	offset += r.length;
+
+	if (signature[offset++] !== ENCODED_TAG_INT) {
+		throw new Error('Could not find expected "int" for "s"');
+	}
+
+	var sLength = signature[offset++];
+
+	if (inputLength - offset !== sLength) {
+		throw new Error('"s" specified length of "' + sLength + '", expected "' + (inputLength - offset) + '"');
+	}
+
+	if (maxEncodedParamLength < sLength) {
+		throw new Error('"s" specified length of "' + sLength + '", max of "' + maxEncodedParamLength + '" is acceptable');
+	}
+
+	var s = signature.slice(offset);
+	offset += s.length;
+
+	if (offset !== inputLength) {
+		throw new Error('Expected to consume entire buffer, but "' + (inputLength - offset) + '" bytes remain');
+	}
+
+	var rPadding = paramBytes - r.length,
+		sPadding = paramBytes - s.length;
+
+	signature = new Buffer(rPadding + r.length + sPadding + s.length);
+
+	for (offset = 0; offset < rPadding; ++offset) {
+		signature[offset] = 0;
+	}
+	r.copy(signature, offset, Math.max(-rPadding, 0));
+
+	offset = paramBytes;
+
+	for (var o = offset; offset < o + sPadding; ++offset) {
+		signature[offset] = 0;
+	}
+	s.copy(signature, offset, Math.max(-sPadding, 0));
+
 	signature = signature.toString('base64');
@@ -68,3 +111,3 @@ signature = base64Url(signature);
 
-function reduceBuffer (buf) {
+function reduceBuffer(buf) {
 	var padding = 0;
@@ -75,3 +118,3 @@ for (var n = buf.length; padding < n && buf[padding] === 0;) {
 
-	var needsSign = buf[padding] >= 0x80;
+	var needsSign = buf[padding] >= MAX_OCTET;
 	if (needsSign) {
@@ -112,19 +155,24 @@ --padding;
 
-	var oneByteLength = rsBytes < 0x80;
+	var shortLength = rsBytes < MAX_OCTET;
 
-	signature = new Buffer((oneByteLength ? 2 : 3) + rsBytes);
+	signature = new Buffer((shortLength ? 2 : 3) + rsBytes);
 
 	var offset = 0;
-	signature[offset++] = (seq | 0x20) | 0 << 6;
-	if (oneByteLength) {
+	signature[offset++] = ENCODED_TAG_SEQ;
+	if (shortLength) {
+		// Bit 8 has value "0"
+		// bits 7-1 give the length.
 		signature[offset++] = rsBytes;
 	} else {
-		signature[offset++] = 0x80 | 1;
+		// Bit 8 of first octet has value "1"
+		// bits 7-1 give the number of additional length octets.
+		signature[offset++] = MAX_OCTET	| 1;
+		// length, base 256
 		signature[offset++] = rsBytes & 0xff;
 	}
-	signature[offset++] = int | (0 << 6);
+	signature[offset++] = ENCODED_TAG_INT;
 	signature[offset++] = r.length;
 	r.copy(signature, offset);
 	offset += r.length;
-	signature[offset++] = int | (0 << 6);
+	signature[offset++] = ENCODED_TAG_INT;
 	signature[offset++] = s.length;
@@ -131,0 +179,0 @@ s.copy(signature, offset);

No alert changes

Improved metrics

Total package byte prevSize

19617

increased by4.3%

Dependency count

1

decreased by-50%

Lines of code

157

increased by12.95%

Worsened metrics

Dev dependency count

9

increased by80%

Number of package files

5

decreased by-16.67%

Number of lines in readme file

66

decreased by-1.49%

Dependency changes

• - Removedasn1.js@^2.0.3

• - Removedasn1.js@2.2.1(transitive)

• - Removedbn.js@2.2.0(transitive)

• - Removedinherits@2.0.4(transitive)

• - Removedminimalistic-assert@1.0.1(transitive)