| var crypto = require("crypto"); |
| var BigInteger = require("jsbn").BigInteger; |
| var ECPointFp = require("./lib/ec.js").ECPointFp; |
| exports.ECCurves = require("./lib/sec.js"); |
| |
| // zero prepad |
| function unstupid(hex,len) |
| { |
| return (hex.length >= len) ? hex : unstupid("0"+hex,len); |
| } |
| |
| exports.ECKey = function(curve, key, isPublic) |
| { |
| var priv; |
| var c = curve(); |
| var n = c.getN(); |
| var bytes = Math.floor(n.bitLength()/8); |
| |
| if(key) |
| { |
| if(isPublic) |
| { |
| var curve = c.getCurve(); |
| // var x = key.slice(1,bytes+1); // skip the 04 for uncompressed format |
| // var y = key.slice(bytes+1); |
| // this.P = new ECPointFp(curve, |
| // curve.fromBigInteger(new BigInteger(x.toString("hex"), 16)), |
| // curve.fromBigInteger(new BigInteger(y.toString("hex"), 16))); |
| this.P = curve.decodePointHex(key.toString("hex")); |
| }else{ |
| if(key.length != bytes) return false; |
| priv = new BigInteger(key.toString("hex"), 16); |
| } |
| }else{ |
| var n1 = n.subtract(BigInteger.ONE); |
| var r = new BigInteger(crypto.randomBytes(n.bitLength())); |
| priv = r.mod(n1).add(BigInteger.ONE); |
| this.P = c.getG().multiply(priv); |
| } |
| if(this.P) |
| { |
| // var pubhex = unstupid(this.P.getX().toBigInteger().toString(16),bytes*2)+unstupid(this.P.getY().toBigInteger().toString(16),bytes*2); |
| // this.PublicKey = new Buffer("04"+pubhex,"hex"); |
| this.PublicKey = new Buffer(c.getCurve().encodeCompressedPointHex(this.P),"hex"); |
| } |
| if(priv) |
| { |
| this.PrivateKey = new Buffer(unstupid(priv.toString(16),bytes*2),"hex"); |
| this.deriveSharedSecret = function(key) |
| { |
| if(!key || !key.P) return false; |
| var S = key.P.multiply(priv); |
| return new Buffer(unstupid(S.getX().toBigInteger().toString(16),bytes*2),"hex"); |
| } |
| } |
| } |
| |