ECDSA implementation

package.json

@@ -27,6 +27,7 @@
   },
   "dependencies": {
     "ecc-jsbn": "0.0.1",
+    "ecc-qj": "git+https://github.com/rynomad/ecc.git",
     "node-forge": "^0.6.20",
     "polyfill-promise": "^4.0.1",
     "sjcl": "^1.0.3"

src/node/algorithms/ECDSA.js

@@ -0,0 +1,66 @@
+var Algorithm = require("./abstract")("ECDSA")
+  , ECC       = require("./shared/ECC")
+  , forge     = require("node-forge")
+  , types     = Algorithm.types
+  , public    = types.public.usage
+  , private   = types.private.usage;
+
+ECC(Algorithm);
+
+Algorithm.checkParams = checkParams;
+
+public.verify = createVerify;
+private.sign  = createSign;
+
+module.exports = Algorithm;
+
+function checkParams(format, algorithm, usages) {
+}
+
+function createSign(key, alg1) {
+  return function ECDSA_SIGN(alg, buf) {
+    var forgehashKey = alg.hash.name.replace(/-/g, '').toLowerCase();
+    var md = forge.md[forgehashKey].create();
+    md.update(buf.toString("binary"));
+    var digest = md.digest().toHex();
+    var signature = key.sign(new Buffer(digest, 'hex'));
+    // Signature is DER encoded, remove it.
+    var decodedSignature = forge.asn1.fromDer(signature.toString("binary"));
+    // We take only the last 32 bytes because values could be padded with 0 at the beginning.
+    return Buffer.concat([
+      new Buffer(decodedSignature.value[0].value, 'binary').slice(-32),
+      new Buffer(decodedSignature.value[1].value, 'binary').slice(-32)
+    ]);
+  };
+}
+
+function pad(buffer) {
+  if (buffer[0] & 0x80) {
+    // If the value starts with 1, we prepend a 0 to assure it is interpreted as a positive number.
+    return Buffer.concat([new Buffer([0]), buffer])
+  }
+  else {
+    return buffer;
+  }
+}
+
+function createVerify(key, alg1){
+  return function ECDSA_VERIFY(alg, buf, sig) {
+    var forgehashKey = alg.hash.name.replace(/-/g, '').toLowerCase();
+    var md = forge.md[forgehashKey].create();
+    md.update(buf.toString("binary"));
+    var digest = md.digest().getBytes();
+    var sigPart1 = pad(sig.slice(0, 32));
+    var sigPart2 = pad(sig.slice(32, 64));
+    var asn1 = forge.asn1;
+    var integer1 = sigPart1.toString("binary");
+    var integer2 = sigPart2.toString("binary");
+    var derSignature = asn1.toDer(asn1.create(asn1.Class.UNIVERSAL, asn1.Type.SEQUENCE, true, [
+      asn1.create(asn1.Class.UNIVERSAL, asn1.Type.INTEGER, false, integer1),
+      asn1.create(asn1.Class.UNIVERSAL, asn1.Type.INTEGER, false, integer2)
+    ])).getBytes();
+    return key.verifySignature(new Buffer(digest, 'binary'), new Buffer(derSignature, 'binary'));
+  }
+}
+
+module.exports = Algorithm;

src/node/algorithms/index.js

@@ -5,3 +5,4 @@ exports["RSASSA-PKCS1-v1_5"] = require("./RSASSA-PKCS1-v1_5");
 exports["HMAC"] = require("./HMAC")
 exports["AES-GCM"] = require("./AES-GCM")
 exports["ECDH"] = require("./ECDH")
+exports["ECDSA"] = require("./ECDSA")

src/node/algorithms/shared/ECC.js

@@ -1,5 +1,7 @@
 var ecc        = require("./ecc.node.js")
   , spkiECCPad = new Buffer("3059301306072a8648ce3d020106082a8648ce3d030107034200","hex");
+  , pkcsPad1   = new Buffer("308187020100301306072A8648CE3D020106082A8648CE3D030107046D306B0201010420", "hex")
+  , pkcsPad2   = new Buffer("A144034200", "hex");
 
 function getCurveKey(namedCurve){
   return ("sec" + namedCurve.replace(/-/g, '').toLowerCase() + "r1");
@@ -28,6 +30,19 @@ function raw_import(publicBytes, alg){
   return new ecc.ECKey(curve, publicBytes, true);
 }
 
+function pkcs8_import(privateBytes, algorithm) {
+  var curvekey = getCurveKey(algorithm.namedCurve)
+    , curve = ecc.ECCurves[curvekey];
+
+  curve.legacy = true;
+
+  return new ecc.ECKey(curve, privateBytes.slice(pkcsPad1.length, pkcsPad1.length + 32), false);
+}
+
+function pkcs8_export(Key) {
+  return Buffer.concat([pkcsPad1, Key.PrivateKey, pkcsPad2, raw_export(Key)]);
+}
+
 function generate(alg){
   var curvekey = getCurveKey(alg.namedCurve)
     , curve = ecc.ECCurves[curvekey];
@@ -40,7 +55,8 @@ function generate(alg){
 function ECC(Algorithm){
   var formats = Algorithm.formats
     , raw     = formats.raw
-    , spki    = formats.spki;
+    , spki    = formats.spki
+    , pkcs8   = formats.pkcs8;
 
   // attach common generator
   Algorithm.generate = generate;
@@ -52,6 +68,9 @@ function ECC(Algorithm){
   spki.import = spki_import;
   spki.export = spki_export;
 
+  pkcs8.import = pkcs8_import;
+  pkcs8.export = pkcs8_export;
+
   return;
 }