What is the right way to use a database with flutter? - mysql

I have an app which interacts with the database directly with mysql1 library like the example below:
Future FetchData() async {
final connection = await MySqlConnection.connect(ConnectionSettings(
host: 'mysql-hostname.example.com',
port: 3306,
user: 'root',
password: 'root',
db: 'testDB',
));
var results = await connection.query('SELECT * FROM `testTable` WHERE 1');
for (var row in results) {
print('${row[0]}');
}
// Finally, close the connection
await connection.close();
}
I wonder if this is a safe and secure method. Because when I build the app I pack all the information (username, password) about connecting my database in the app. Is this risky so should I use a separate back-end for this kind of tasks?

It is generally safer to put a trusted backend environment between your database and app. But even in this case you will have to ensure that only your app has access to this backend resource.
For example if you use Firebase as backend, there is an AppCheck service available. Although this is relatively new, it can attest your app's authenticity.
If you prefer to do it on your own, you can create a bearer token that your app will add the the requests, preferably in the request's Authorization header, and check it in the backend before accessing protected resources. But then the question remains, where do you store this bearer token safely.
If you want to keep it in your code, you should properly obfuscate the code before uploading it to the app stores. Even in this case it is a good idea to check for rooted or jailbroken devices to prevent misuse, for example check out flutter_jailbreak_detection.
There are also secure storage packages, which can store sensitive data in a safer way. Unlike SharedPreferences, these can mitigate the risks of unauthorited access to your secrets. See flutter_secure_storage for example.

It really depends on the level of security that you are looking for. Are you storing user-generated sensitive information in your database? Then the answer is that you should ideally not store that information in your code nor should you ship your application with that information bundled inside it.
I highly suggest that you start using Firebase for your usage. Firebase is an absolutely fantastic and free product provided by the Google, the same company behind Flutter, and within a few minutes you can build a whole experience that relies on authentication with Firebase and you can safely store user-generated content in Firebase.

Related

Best Practice to Safely Migrate Database in SailsJS App when using Mysql

I have an application developed with SailsJS and mysql. Only a logged in user is meant to be able to create a fresh user. During development stage, I made creation of the first user easy with a simple request to server. That is however not feasible again as I have written some policy codes to prevent such.
module.exports= async function(req, res, proceed){
const adminId = req.param('adminId');
if(!adminId){
return res.status(401).json({status: 401, message: 'Unauthorized access, invalid user'});
}
//let's check if the user has a role as superadmin
const superAdmin = await Admin.findOne({id: adminId, superAdmin: true});
console.log(superAdmin)
if(superAdmin){
return proceed();
}
else{
return res.status(401).json({status: 401, message: "Unauthorized access. You don't have this privilege"})
}
}
Also, Every saved new user has a compulsory createdBy column in mysql database.
I currently want to host the project on production. What best way should I do this. By default, I am supposed to run
sails lift --prod
On production environment and generate the mysql tables. However, I won't be able to login or create an admin user. So what is the best way for me to create a new user?
The "best" way is obviously subjective. Personally I would write a migration to bootstrap the DB with the first production user (you are using migrations, right?).
Some people eschew including DML in their migrations, although in my experience at some point in the long lifetime of an application under development, some type of "data fixup" needs to happen. Doing it as idempotently as possible in a migration has been the easiest and most reliable approach.

Custom service/route creation using feathersjs

I have been reading the documentation for last 2 days. I'm new to feathersjs.
First issue: any link related to feathersjs is not accessible. Such as this.
Giving the following error:
This page isn’t working
legacy.docs.feathersjs.com redirected you too many times.
Hence I'm unable to traceback to similar types or any types of previously asked threads.
Second issue: It's a great framework to start with Real-time applications. But not all real time application just require alone DB access, their might be access required to something like Amazon S3, Microsoft Azure etc. In my case it's the same and it's more like problem with setting up routes.
I have executed the following commands:
feathers generate app
feathers generate service (service name: upload, REST, DB: Mongoose)
feathers generate authentication (username and password)
I have the setup with me, ready but how do I add another custom service?
The granularity of the service starts in the following way (Use case only for upload):
Conventional way of doing it >> router.post('/upload', (req, res, next) =>{});
Assume, I'm sending a file using data form, and some extra param like { storage: "s3"} in the req.
Postman --> POST (Only) to /upload ---> Process request (isStorageExistsInRequest?) --> Then perform the actual upload respectively to the specific Storage in Req and log the details in local db as well --> Send Response (Success or Failure)
Another thread on stack overflow where you have answered with this:
app.use('/Category/ExclusiveContents/:categoryId', {
create(data, params) {
// do complex stuff here
params.categoryId // the id of the category
data // -> additional data from the POST request
}
});
The solution can viewed in this way as well, since featherjs supports micro service approach, It would be great to have sub-routes like:
/upload_s3 -- uploads to s3
/upload_azure -- uploads to azure and so on.
/upload -- main route which is exposed to users. User requests, process request, call the respective sub-route. (Authentication and Auth to be included as well)
How to solve these types of problems using existing setup of feathersjs?
1) This is a deployment issue, Netlify is looking into it. The current documentation is not on the legacy domain though, what you are looking for can be found at docs.feathersjs.com/api/databases/querying.html.
2) A custom service can be added by running feathers generate service and choosing the custom service option. The functionality can then be implemented in src/services/<service-name>/<service-name>.class.js according to the service interface. For file uploads, an example on how to customize the parameters for feathers-blob (which is used in the file uploading guide) can be found in this issue.

Sync indexedDB with mysql database

I am about to develop an application where employees go to service repair machines at customer premises. They need to fill up a service card using a tablet or any other mobile device.
In case of no Internet connection, I am thinking about using HTML5 offline storage, mainly IndexedDB to store the service card (web form) data locally, and do a sync at the office where Internet exists. The sync is with a MySQL database.
So the question: is it possible to sync indexedDB with mysql? I have never worked with indexedDB, I am only doing research and saw it is a potential.
Web SQL is deprecated. Otherwise, it could have been the closer solution.
Any other alternatives in case the above is difficult or outside the standard?
Your opinions are highly appreciated.
Thanks.
This is definitly do able. I am only just starting to learn indexeddb the last couple of days. This is how I would see it working tho. Sorry dont have code to give you.
Website knows its in offline mode somehow
Clicking submit form saves the data into indexeddb
Later laptop or whatever is back online or on intranet and can now talk to main server sends all indexeddb rows to server to be stored in mysql via an ajax call.
indexeddb is cleared
repeat
A little bit late, but i hope it helps.
This is posible, am not sure if is the best choice. I can tell you that am building a webapp where I have a mysql database and the app must work offline and keep trace of the data. I try using indexedDB and it was very confusing for me so I implemented DexieJs, a minimalistic and straight forward API to comunicate with indexedDB in an easy way.
Now the app is working online then if it goes down the internet, it works offline until it gets internet back and then upload the data to the mysql database. One of the solutions i read to save the data was to store in a TEXT field the json object been passed to JSON.stringify(), and once you need the data back JSON.parse().
This was my motivation to build the app in that way and also that we couldn't change of database :
IndexedDB Tutorial
Sync IndexedDB with MySQL
Connect node to mysql
[Update for 2021]
For anyone reading this, I can recommend to check out AceBase.
AceBase is a realtime database that enables easy storage and synchronization between browser and server databases. It uses IndexedDB in the browser, and its own binary db format or SQL Server / SQLite storage on the server side. MySQL storage is also on the roadmap. Offline edits are synced upon reconnecting and clients are notified of remote database changes in realtime through a websocket (FAST!).
On top of this, AceBase has a unique feature called "live data proxies" that allow you to have all changes to in-memory objects to be persisted and synced to local and server databases, so you can forget about database coding altogether, and program as if you're only using local objects. No matter if you're online or offline.
The following example shows how to create a local IndexedDB database in the browser, how to connect to a remote database server that syncs with the local database, and how to create a live data proxy that eliminates further database coding altogether.
const { AceBaseClient } = require('acebase-client');
const { AceBase } = require('acebase');
// Create local database with IndexedDB storage:
const cacheDb = AceBase.WithIndexedDB('mydb-local');
// Connect to server database, use local db for offline storage:
const db = new AceBaseClient({ dbname: 'mydb', host: 'db.myproject.com', port: 443, https: true, cache: { db: cacheDb } });
// Wait for remote database to be connected, or ready to use when offline:
db.ready(async () => {
// Create live data proxy for a chat:
const emptyChat = { title: 'New chat', messages: {} };
const proxy = await db.ref('chats/chatid1').proxy(emptyChat); // Use emptyChat if chat node doesn't exist
// Get object reference containing live data:
const chat = proxy.value;
// Update chat's properties to save to local database,
// sync to server AND all other clients monitoring this chat in realtime:
chat.title = `Changing the title`;
chat.messages.push({
from: 'ewout',
sent: new Date(),
text: `Sending a message that is stored in the database and synced automatically was never this easy!` +
`This message might have been sent while we were offline. Who knows!`
});
// To monitor realtime changes to the chat:
chat.onChanged((val, prev, isRemoteChange, context) => {
if (val.title !== prev.title) {
console.log(`Chat title changed to ${val.title} by ${isRemoteChange ? 'us' : 'someone else'}`);
}
});
});
For more examples and documentation, see AceBase realtime database engine at npmjs.com

How to do authentication in node.js that I can use from my website?

I want a Node.js service to authenticate the user of my website. How can I do this?
I want to implement Everyauth authentication using the simple password method, not OpenID.
I tried https://github.com/jimpick/everyauth-example-password and it works.
I want to use the database to store. This script does not use a database. I have used MySQL in past so I prefer that but I am ok with anything else as well such as MongoDB.
I just want to add database to my script. Please help.
You only need to modify .authenticate method. Since connecting to database is (or should be) an asynchronous operation, then you need to add promise object (see everyauth documentation).
Assuming you have some ORM with user data corresponding to user object with username and password attributes (in my example I'll use mongoose engine), this is how it may look:
.authenticate( function (login, password) {
var promise = this.Promise(); /* setup promise object */
/* asynchrnously connect to DB and retrieve the data for authentication */
db.find({ username:login }, function(err, user) {
if (err)
return promise.fulfill([err]);
if ((!user) || (user.password != password))
return promise.fulfill(['Incorrect username or password!']);
promise.fulfill(user);
});
return promise; /* return promise object */
})
I didn't test it, but according to the documentation it should work. Remember that errors are supposed to be held in array.
By the way: if you are using only the password method, then there is no need to, you know, use a cannon against a fly. :) Writing your own (not necessarly perfect, but working) authentication mechanism is really simple and if you don't know how to do this you should learn it. It will benefit in the future, because authentication and security in general are very important in every web app.

How can I let users register my product online?

I've a MySql database hosted in my web site, with a table named UsrLic
Where any one wants to buy my software must register and enter his/her Generated Machine Key (+ username, email ...etc).
So my question is:
I want to automate this process from my software, how this Process will be?
Should I connect and update my database directly from my software ( and this means I must save all my database connection parameters in it * my database username , password , server * and then use ADO or MyDac to connect to this database ? and if yes how secure is this process ?
or any other suggestions .
I recommend creating an API on your web site in PHP and calling the API from Delphi.
That way, the database is only available to your web server and not to the client application, ever. In fact, you should run your database on localhost or with a private IP so that only machines on the same physical network can reach it.
I have implemented this and am implementing it again as we speak.
PHP
Create a new file named register_config.php. In this file, setup your MySQL connection information.
Create a file named register.php. In this file, put your registration functions. From this file, include 'register_config.php'. You will pass parameters to the functions you create here, and they will do the reading and writing to your database.
Create a file named register_api.php. From this file, include 'register.php'. Here, you will process POST or GET variables that are sent from your client application, call functions in register.php, and return results back to the client, all via HTTP.
You will have to research connecting to and querying a MySQL database. The W3Schools tutorials will have you doing this very quickly.
For example:
Your Delphi program calls https://mysite/register_api.php with Post() and sends the following values:
name=Marcus
email=marcus#gmail.com
Here's how the beginning of register_api.php might look:
// Our actual database and registration functions are in this library
include 'register.php';
// These are the name value pairs sent via POST from the client
$name = $_POST['name'];
$email = $_POST['email'];
// Sanitize and validate the input here...
// Register them in the DB by calling my function in register.php
if registerBuyer($name, $email) {
// Let them know we succeeded
echo "OK";
} else {
// Let them know we failed
echo "ERROR";
}
Delphi
Use Indy's TIdHTTP component and its Post() or Get() method to post data to register_api.php on the website.
You will get the response back in text from your API.
Keep it simple.
Security
All validation should be done on the server (API). The server must be the gatekeeper.
Sanitize all input to the API from the user (the client) before you call any functions, especially queries.
If you are using shared web hosting, make sure that register.php and register_config.php are not world readable.
If you are passing sensitive information, and it sounds like you are, you should call the registration API function from Delphi over HTTPS. HTTPS provides end to end protection so that nobody can sniff the data being sent off the wire.
Simply hookup a TIdSSLIOHandlerSocketOpenSSL component to your TIdHTTP component, and you're good to go, minus any certificate verification.
Use the SSL component's OnVerifyPeer event to write your own certificate verification method. This is important. If you don't verify the server side certificate, other sites can impersonate you with DNS poisoning and collect the data from your users instead of you. Though this is important, don't let this hold you up since it requires a bit more understanding. Add this in a future version.
Why don't you use e.g. share*it? They also handle the buying process (i don't see how you would do this for yourself..) and let you create a reg key through a delphi app.