What would be the most proper way to send email? - node.js

I'm learning TypeOrm and i'm trying to implement an email verification system after a user creates an account.
Let's say i have two entities, User and EmailVerification. When the user is created, an EmailVerification related to this user is inserted in the database. The next step would be to send an email to this user right after the EmailVerification is created.
But i'm not sure about what typeOrm feature to use to call my email service send function.
I was thinking of two ways to achieve this,
1 - From the transaction as a complementary step after inserting user and emailVericiation in database :
await getManager().transaction(async entityManager => {
await entityManager.save(user);
await entityManager.save(emailVerification);
// send the message directly from the transaction right after the user and emailVerification is created
await emailService.send(message);
})
2 - From an EntitySubscriber right after the creation of the EmailEntity :
#EventSubscriber()
export class EmailVerificationSubscriber implements EntitySubscriberInterface<EmailVerification> {
#AfterInsert()
sendEmail() {
// ... //
// get related user email
// ... //
// then send the message
await emailService.send(message);
}
}
These two ways seems sufficient to me, but i would like to know if there is some kind of best practice for this use case ?
I can provide more informations if needed

It doesn't matter very much which option you choose.
That being said, the email you send is part of a workflow that starts when you insert your emailVerification object. So it makes sense to associate it with that operation.
If you use a similar workflow in future for password recovery, it will become obvious why that makes sense.

Related

REST API - How to implement user specific authorisation?

So I'm currently learning/building a REST API backend server for my web application using NodeJS, ExpressJS, and MySQL as the database. My question is in regards to the best way to implement authorisation to ensure User A does not access or edit the data belonging to another User. Please note that I understand there are a lot of examples for implementation of role based authorisation (ie user groups vs admin groups, etc) but this is not what I'm asking. Instead, how do I authorise a user against the data they are accessing?
It is possible that I'm overthinking this and this is not even necessary; that I should just check whether the data belongs to the user in every SQL query, but I thought I'd ask if there's a middleware or policy architecture that takes care of this, or maybe even authorise through caching.
The only solution I can think of is that every SQL query returns the the user id with the result, then I just create a service that checks every result if the id matches or not. If yes, then proceed. If not rollback the query and return unauthorised error. Is this ok?
I very much appreciate your advice, help, and if you can point me in the right direction.
Many thanks in advance.
Save the userId (or ownerId) in every table, and create a middleware where each db access method requires the userId as a parameter, for example:
readOne(id, userId) {
// implements SELECT * FROM example WHERE id = id AND userId = userId
}
updateOne(id, data, userId) {
// implements UPDATE example SET data = data WHERE id = id AND userId = userId
}
...
For security reasons, never send as a response "Requested data exist by you aren't the owner".
The simplest things usually work best. You wouldn't have to have a special service for checking authorization rights for every entity and you can do it at data access level eg. SELECT * FROM foo WHERE user_id = :currentUser or UPDATE foo SET foo = bar WHERE user_id = :currentUser
It also depends whether you want to notify the user about unallowed access via HTTP401 or not to reveal that such a resource even exists for different user HTTP404.
For HTTP401 the scenario would be:
const entity = loadFromDB(id);
if(entity.userId !== currentUserId) {
res.send(401);
return;
}
... update entity logic ...

Permission for all users to post to a specific feed

I have been attempting to implement stream via react native and seem to be struggling with what looks like a permissions issue in relation to all users being unable to post to another 'entities' feed. My use case is essentially several 'topic' pages, where all users of my app can post to and comment etc. The topic page will also have an owner who can manage the page if needs be, so they too are essentially a 'user.
I've read elsewhere that global write permissions are not enabled by default so may need a member of the stream team to look at this for me if possible.
Here is the code I'm trying to use on the client side:
let user = client.feed('user', "bob");
let activity = {
actor: "bob",
verb: 'post',
object: "Hello world",
foreign_id: 'post:1',
to: ['user:topic-page-1'],
};
user
.addActivity(activity)
.then(data => {
console.log('success');
})
.catch(reason => {
alert(reason);
});
Another small issue I can't seem to get to the bottom of, is even when posting to the same user's timeline, the post username is always displaying as "Unknown" no matter what data I attach. What am I getting wrong here please?
For the actor field to be treated as a user entity, you should use a reference, something like client.currentUser or client.user('bob'). This should fix your post username issue.

Stripe - create / retrieve customer in one call

Is there a stripe API call that we can use to create a user if they don't exist, and retrieve the new user?
say we do this:
export const createCustomer = function (email: string) {
return stripe.customers.create({email});
};
even if the user with that email already exists, it will always create a new customer id. Is there a method that will create a user only if the user email does not exist in stripe?
I just want to avoid a race condition where more than one stripe.customers.create({email}) calls might happen in the same timeframe. For example, we check to see if customer.id exists, and does not, two different server requests could attempt to create a new customer.
Here is the race condition:
const email = 'foo#example.com';
Promise.all([
stripe.customers.retrieve(email).then(function(user){
if(!user){
return stripe.customers.create(email);
}
},
stripe.customers.retrieve(email).then(function(user){
if(!user){
return stripe.customers.create(email);
}
}
])
obviously the race condition is more likely to happen in two different processes or two different server requests, than the same server request, but you get the idea.
No, there is no inbuilt way to do this in Stripe. Stripe does not require that a customer's email address be unique, so you would have to validate it on your side. You can either track your users in your own database and avoid duplicates that way, or you can check with the Stripe API if customers already exist for the given email:
let email = "test#example.com";
let existingCustomers = await stripe.customers.list({email : email});
if(existingCustomers.data.length){
// don't create customer
}else{
let customer = await stripe.customers.create({
email : email
});
}
Indeed it can be solved by validating stripe's customer data retrieval result against stored db.
And then call another API to create afterward.
However for simplicity sake, i agree with #user7898461 & would vouch for retrieveOrCreate customer api :)
As karllekko's comment mentions, Idempotent Keys won't work here because they only last 24 hours.
email isn't a unique field in Stripe; if you want to implement this in your application, you'll need to handle that within your application - i.e., you'll need to store [ email -> Customer ID ]s and do a lookup there to decide if you should create or not.
Assuming you have a user object in your application, then this logic would be better located there anyways, as you'd also want to do this as part of that - and in that case, every user would only have one Stripe Customer, so this would be solved elsewhere.
If your use case is like you don't want to create a customer with the same email twice.
You can use the concept of stripe idempotent request. I used it to avoid duplicate charges for the same order.
You can use customer email as an idempotent key. Stripe handles this at their end. the two request with same idempotent key won't get processed twice.
Also if you want to restrict it for a timeframe the create an idempotent key using customer email and that time frame. It will work.
The API supports idempotency for safely retrying requests without
accidentally performing the same operation twice. For example, if a
request to create a charge fails due to a network connection error,
you can retry the request with the same idempotency key to guarantee
that only a single charge is created.
You can read more about this here. I hope this helps

Getting the user id from a Firestore Trigger in Cloud Functions for Firebase?

In the example bellow, is there a way to get the user id (uid) of the user who wrote to 'offers/{offerId}'? I tried to do as described here but it doesn't work in Firestore.
exports.onNewOffer = functions.firestore
.document('offers/{offerId}')
.onCreate(event => {
...
});
I was struggling on this for a while and finally contacted the firebase Support:
The event.auth.uid is undefined in the event object for firestore database triggers. (It works for the realtime Database Triggers)
When I console.log(event) I can’t find any auth in the output.
The official support answer:
Sorry the auth is not yet added in the Firestore SDK. We have it listed in the next features.
Keep an eye out on our release notes for any further updates.
I hope this saves someone a few hours.
UPDATE:
The issue has been closed and the feature will never be implemeted:
Hi there again everyone - another update. It has been decided that unfortunately native support for context.auth for Firestore triggers will not be implemented due to technical constraints. However, there is a different solution in the works that hopefully will satisfy your use case, but I cannot share details. On this forum we generally keep open only issues that can be solved inside the functions SDK itself - I've kept this one open since it seemed important and I wanted to provide some updates on the internal bugs tracking this work. Now that a decision has been reached, I'm going to close this out. Thanks again for everyone's patience and I'm sorry I don't have better news. Please use the workaround referenced in here.
Summary of how I solved this / a workable solution:
On client
Add logged in/current user's uid (e.g. as creatorId) to entity they're creating. Access this uid by storing the firebase.auth().onAuthStateChanged() User object in your app state.
In Firebase Firestore/Database
Add a Security Rule to create to validate that the client-supplied creatorId value is the same as the authenticated user's uid; Now you know the client isn't spoofing the creatorId and can trust this value elsewhere.
e.g.
match /entity/{entityId} {
allow create: if madeBySelf();
}
function madeBySelf() {
return request.auth.uid == request.resource.data.creatorId;
}
In Firebase Functions
Add an onCreate trigger to your created entity type to use the client-supplied, and now validated, creatorId to look up the creating user's profile info, and associate/append this info to the new entity doc.
This can be accomplished by:
Creating a users collection and individual user documents when new accounts are created, and populating the new user doc with app-useful fields (e.g. displayName). This is required because the fields exposed by the Firebase Authentication system are insufficient for consumer app uses (e.g., displayName and avatarURL are not exposed) so you can't just rely on looking up the creating user's info that way.
e.g. (using ES6)
import * as functions from 'firebase-functions'
import * as admin from 'firebase-admin'
const APP = admin.initializeApp()
export const createUserRecord = functions.auth.user()
.onCreate(async (userRecord, context) => {
const userDoc = {
id: userRecord.uid,
displayName: userRecord.displayName || "No Name",
avatarURL: userRecord.photoURL || '',
}
return APP.firestore().collection('users').doc(userRecord.uid).set(userDoc)
})
Now that you have a validated creatorId value, and useful user objects, add an onCreate trigger to your entity type (or all your created entities) to look up the creating user's info and append it to the created object.
export const addCreatorToDatabaseEntry = functions.firestore
.document('<your entity type here>/{entityId}')
.onCreate(async (snapshot, context) => {
const userDoc = await APP.firestore().collection('users').doc(snapshot.data().creatorId).get()
return snapshot.ref.set({ creator: userDoc.data() }, { merge: true })
})
This clearly leads to a lot of duplicated user info data throughout your system -- and there's a bit of clean up you can do ('creatorId` is duplicated on the created entity in the above implementation) -- but now it's super easy to show who created what throughout your app, and appears to be 'the Firebase way'.
Hope this helps. I've found Firebase to be super amazing in some ways, and make some normally easy things (like this) harder than they 'should' be; on balance though am a major fan.
The documentation states clearly that the context.auth param is only available in the Realtime Database.
This field is only populated for Realtime Database triggers and
Callable functions. For an unauthenticated user, this field is null.
For Firebase admin users and event types that do not provide user
information, this field does not exist.
Personally I realized that I had the userId already in the path of my data.
export const onCreate = functions.firestore.document('docs/{userId}/docs/{docId}')
.onCreate((snapshot, context) => {
const userId = context.params.userId;
Until this is added to firestore functions a workaround is to add the user_id as a field when creating a document then deleting after. You can then grab it in the function onCreate then after you use it for what you need it for, while still in the function, just delete the field from that document.
As already suggested above, the workaround will be to add a user_id field with the data itself and then read it on the server.
The drawback with this approach will be a security loophole. As we are not verifying the user id on the server, any other user will be able to impersonate other users by sending their id with the data.
For security critical applications, the solution for this will be to use security rules to verify that the correct user_id has been sent with the data
allow write: if resource.data.user_id == request.auth.uid;
You could add your data via Callable function, from which you can access current user id:
exports.addNewOffer = functions.https.onCall(async (data, context) => {
const uid = context.auth.uid
const writeResult = await admin.firestore().collection('offers').add({ ... })
...
return { id: writeResult.id, ... }
})
What is about snap._fieldsProto.uid.stringValue
Example:
exports.hello = functions.firestore.document('hello/{worldId}').onCreate((snap, context) => {
console.log(snap._fieldsProto.uid.stringValue)
});
This should do the trick:
exports.newMessage = functions.firestore
.document('groups/messages/{messageId}')
.onCreate((snap, context) => {
var fromId = snap.data().fromId;
You can get the current signed-in user tokenId by calling getIdToken() on the User: https://firebase.google.com/docs/reference/functions/functions.auth.UserInfo

REST API Endpoint for changing email with multi-step procedure and changing password

I need help for creating the REST endpoints. There are couple of activities :
To change the email there are 3 URL requests required:
/changeemail : Here one time password (OTP) is sent to the user's mobile
/users/email : the user sends the one time password from previous step and system sends the email to the new user to click on the email activate link
/activateemail : user clicks on the link in the new email inbox and server updates the new email
To change password :
/users/password (PATCH) : user submits old password and new password and system accordingly updates the new password
Similarly, there are other endpoints to change profile (field include bday, firstname and last name)
after reading online I believe my system as only users as the resource --> so to update the attributes I was thinking of using a single PATCH for change email and change password and along with that something like operation field so the above two features will look like :
For changing email :
operation : 'sendOTPForEmailChange'
operation : 'sendEmailActivationLink'
operation : 'activateEmail'
For changing password :
operation : 'changePassword'
and I will have only one endpoint for all the above operations that is (in nodejs) :
app.patch('/users', function (req, res) {
// depending upon the operation I delegate it to the respective method
if (req.body.operation === 'sendOTPForEmailChange') {
callMethodA();
} else if (req.body.operation === 'sendEmailActivationLink') {
callMethodB();
} else if (req.body.operation === 'activateEmail') {
callMethodC();
} else if (req.body.operation === 'changePassword') {
callMethodC();
} else sendReplyError();
});
Does this sound a good idea ? If not, someone can help me form the endpoints for changeemail and changepassword.
Answer :
I finally settled for using PATCH with operation field in the HTTP Request Body to indicate what operation has to be performed.
Since I was only modifying a single field of the resource I used the PATCH method.
Also, I wanted to avoid using Verbs in the URI so using 'operation' field looked better.
Some references I used in making this decision :
Wilts answer link here
Mark Nottingham' blog link article
and finally JSON MERGE PATCH link RFC
You should make the links that define the particular resource, avoid using PATCH and adding all the logic in one link keep things simple and use separation of concern in the API
like this
1- /users/otp with HTTP Verb: GET -> to get OTP for any perpose
2- /users/password/otp with HTTP Verb: POST -> to verify OTP for password and sending link via email
3- /users/activate with HTTP Verb: POST to activate the user
4- /users/password with HTTP Verb: PUT to update users password
Hashing Security is a must read, IMHO, should you ever want to implement your own user account system.
Two-factor identification should always be considered, at least as an opt-in feature. How would you integrate it into your login scheme ?
What about identity federation ? Can your user leverage their social accounts to use your app ?
A quick look at Google yielded this and this, as well as this.
Unless you have an excellent reason to do it yourself, I'd spend time integrating a solution that is backed by a strong community for the utility aspects of the project, and focus my time on implementing the business value for your customers.
NB: my text was too long for the comments
Mostly agree with Ghulam's reply, separation of concerns is key. I suggest slightly different endpoints as following:
1. POST /users/otp -> as we are creating a new OTP which should be returned with 200 response.
2. POST /users/email -> to link new email, request to include OTP for verification.
3. PUT /users/email -> to activate the email.
4. PUT /users/password -> to update users password.

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