ecdsa.js

var BN = require('bn.js');
var EC = require('elliptic').ec;

var ec = new EC('secp256k1');

// Create key pair from secret
var key = ec.keyFromPrivate('00000000000000000000000000000000000000000000000000000000000000A5');
console.log('PRIVATE: ' + key.getPrivate('hex'));
console.log('PUBLIC: ' + key.getPublic('hex'));
console.log('ADDRESS: ' + '16NzBsb7vAboEfdbdsnno4Dfc5xuMECL85'); // http://gobittest.appspot.com/Address

// Sign the message's hash (input must be an array, or a hex-string)
var msgHash = '0000000000000000000000000000000000000000000000000000000000000076';
var signOptions = {
	k: function(iter) {
		return new BN('0000000000000000000000000000000000000000000000000000000000000042', 16);
	}
};
var signature = key.sign(msgHash, signOptions);
console.log(signature);
console.log(signature.toDER('hex'));

// signature in DER format
var signature = '30450220079264c4b4bfcd7fe3a7b7b92b6c439f3a5b3abcd29189bf7b54d781ff03d722022100ec24497f28b8b80d4c8824853a220de6342addca559231c7b42d633c77e62e4c';
console.log(key.verify(msgHash, signature));