index.js

'use strict'
const AWS = require('aws-sdk');
const model = require('./model/user.js')
const crypto = require('crypto');

exports.handler = function (user, context, callback) {
    console.log(user);
    user = sha512(user);
    console.log(user);
    var dynamodb = new AWS.DynamoDB();
    var dynamoUser = model.User(user);
    console.log("testing this")
    console.log(dynamoUser);
    /*
    dynamodb.putItem(dynamoUser, function(err, data) {
        if (err){
            console.log(err, err.stack); // an error occurred
        context.fail('Failed!')
    }else{
            console.log(data);   
            context.succeed('Success!')
        }

      });
*/
}

var sha512 = function(user){
    var salt = genRandomString(32);
    var hash = crypto.createHmac('sha512', salt); /** Hashing algorithm sha512 */
    hash.update(user.password);
    user.password = hash.digest('hex');
    user.salt = salt;
    return user;
};

var genRandomString = function(length){
    return crypto.randomBytes(Math.ceil(length/2))
            .toString('hex') /** convert to hexadecimal format */
            .slice(0,length);   /** return required number of characters */
};

user.js

class User {
  constructor(user){
  user = user;
  dynamoUser = {
    Item: {
     "password": {
       S: user.password
      }, 
     "email": {
       S: user.email
      }, 
     "salt": {
       S: user.salt
      }, 
      "createdOn": {
        S :getCreatedOn()
       }
    }, 
    ReturnConsumedCapacity: "TOTAL", 
    TableName: "source.user"
   };
  }
}

function getCreatedOn(){
  var now = new Date;
  var utc_timestamp = Date.UTC(now.getUTCFullYear(),now.getUTCMonth(), now.getUTCDate() , 
        now.getUTCHours(), now.getUTCMinutes(), now.getUTCSeconds(), now.getUTCMilliseconds());
        return utc_timestamp.toLocaleString();
}

exports.User = function(user){return new User(user);}