//create custom json serialization format
var JsonFormatter = {
	stringify: function (cipherParams) {
		// create json object with ciphertext
		var jsonObj = {
			ct: cipherParams.ciphertext.toString(CryptoJS.enc.Base64)
		};
		
		// optionally add iv and salt
		if (cipherParams.iv) {
			jsonObj.iv = cipherParams.iv.toString();
		}
		
		if (cipherParams.salt) {
			jsonObj.s = cipherParams.salt.toString();
		}

		// stringify json object
		return JSON.stringify(jsonObj)
	},

	parse: function (jsonStr) {
		// parse json string
		var jsonObj = JSON.parse(jsonStr);
		
		// extract ciphertext from json object, and create cipher params object
		var cipherParams = CryptoJS.lib.CipherParams.create({
			ciphertext: CryptoJS.enc.Base64.parse(jsonObj.ct)
		});
		
		// optionally extract iv and salt
		if (jsonObj.iv) {
			cipherParams.iv = CryptoJS.enc.Hex.parse(jsonObj.iv);
		}
            
		if (jsonObj.s) {
			cipherParams.salt = CryptoJS.enc.Hex.parse(jsonObj.s);
		}
		
		return cipherParams;
	}
};