MongoDB, insert many only if no match - mongodb

I'm making a token system along with a payment rule.
I need an idempotent rule that will generate some token for user (One for each token he bought)
So i have the following token
{
_id?: ObjectId;
owner: ObjectId;
type: string;
origin: {
paymentIntentId: string;
date: Date;
}
}
It can exists multiple tokens for one paymentIntentId but if multiple call try to create token for the same token (let's say 4) for one paymentIntentId that already own token, i would like to prevent or do a no-op.
How can i proceed ?
I'm having concurrency issue with prevent me to first query then update because the A check appears before the B insert.
Best regards

Related

Web Push API - alternatives for saving VAPID Private key in Database

I am currently working on the implementation of push notifications. To do this, the web push api requires the subscription object which contains the public as well as the private key. Additionally the subscription needs to be stored in a database for later use.
#################
#Subscription Object
#################
endpoint: { type: String, unique: true},
keys: {
p256dh: {type: String},
auth: {type: String}
},
#################
#Sending the Notification
#################
webpush.sendNotification(subscription, payload).catch(console.log);
Personally, I am not sure if I should save the private key in the database.
Is there a better approach to this?
Or is it actually safe to store this information in this format?

Is there a way to setup a field-level authorisation on FaunaDB + GraphQL?

I'm having troubles finding a way to hide user emails from everyone, except the owner (user has access to only his email). Is there a way to hide a certain document field, for a certain roles?
Here is an example I found that creates a role with dynamic access to the whole User collection:
CreateRole({
name: "tier1_role",
membership: {
resource: Collection("User"),
predicate: Query(
Lambda("userRef",
// User attribute based rule:
// It grants access only if the User has TIER1 role.
// If so, further rules specified in the privileges
// section are applied next.
Equals(Select(["data", "role"], Get(Var("userRef"))), "TIER1")
)
)
},
privileges: [
{
// Note: 'allUsers' Index is used to retrieve the
// documents from the File collection. Therefore,
// read access to the Index is required here as well.
resource: Index("allUsers"),
actions: { read: true }
}
]
})
I tried to change it a bit, but I wasn't able to set up field-level access.
Let's say I'd set up FaunaDB with GraphQL schema below.
enum UserRole {
TIER1
}
type User {
email: String! #unique
username: String! #unique
role: UserRole!
}
type Query {
allUsers: [User!]
}
type Mutation {
addUsers(new_users: [UserInput]): [User]
#resolver(name: "add_users", paginated: false)
}
How do create a FaunaDB role in such a way that all of the users (except the current one) in resulting array from allUsers query, will not have email field?
I could break User collection into two: one is public, the other is accessible to a document owner, but this sounds wrong.
I'm new to the noSQL concept, so maybe I'm looking at this problem from the wrong perspective?
it's a request that came up a few times. You probably want to do this straight in FaunaDB's ABAC role system but although it provides row-level security, hiding a specific field is currently not provided yet. The feedback has been logged though, we will look into it.
The current way to do this is to split out Users from Accounts and fetch Users instead of Accounts. It would be useful to have something like hidden fields though in the future.
If you think of it, in this case, it does make sense to split authentication information from User information. You never know that you might offer another way to authentication in the future. I still recall from the Phoenix Framework book that they do it there was well and considered it a good practice.
You could also make a thin wrapper using Apollo in a serverless function and filter out these fields when you pass through the results. There is a guide that explains how to build such a thin Apollo middleware that just delegates to FaunaDB https://www.gatlin.io/blog/post/social-login-with-faunadb-and-auth0

How to hide properties on Azure Mobile Service responses?

I have a Mobile Service with Model classes and DTO classes. I mapped these using Fluent API and got it to work to perform CRUD operations, but I have a problem with the JSON responses returned in some instances.
Take for example a User entity with user name and password. To register a user I have my PostUserDTO method like this:
// POST tables/UserDTO
public async Task<IHttpActionResult> PostUserDTO(UserDTO item)
{
string hashString = PasswordHash.CreateHash(item.Password);
item.Password = hashString;
UserDTO current = await InsertAsync(item);
current.Password = "";
return CreatedAtRoute("Tables", new { id = current.Id }, current);
}
On the method I read the password property sent from the client and then proceed to hash it with a salt, replace the value in the object sent and save it to the database, then I proceed to empty the password so the hashed result isn't returned.
In this case the best practice would be to omit the password property from the response, this also should happen when retrieving all of the users in the table, I only want to return specific information, some information generated by my server should stay out from the response.
How can I select or alter the information from the responses? Do I have to create other DTOs for every kind of response I desire?

In a RESTful system, how to make request to a unique server api that doesn't have an id

Now my system has some api that doesn't have an unique id, so how to make request from ember data.
Because find method needs an id, but i don't have it.
Current, my solution is use pure AJAX call to fetch this kind of data.
So is there have any better solution to make this happen.
I guess you should be using DS.RESTSerializer, if so you could specific custom primaryKey for each Model or global to your app.
For Global App.
App.ApplicationSerializer = DS.RESTSerializer({
primaryKey: 'customId'
});
If your behavior is for a couple model, you do the same for those models.
App.MyModel = DS.Model.extend({
name: DS.attrs('string')
});
App.MyModelSeriliazer = App.ApplicationSerializer.extend({
primaryKey: 'customId'
});
EmberJS would map this customId to id in ember-data.

Resource level authorization in RESTful service

Let /users/{id} be a resource url in RESTful service.
Basic authentication is enabled and only authenticated users are allowed to access the url.
Example Scenario:
User_1 & User_2 are authenticated users with userId 1 & 2.
Since both are authenticated, both of them are having access to,
/users/1
/users/2
But the expectation is User_1 should have access to /users/1 and not to /users/2 or other userId.
Question:
How to do resource level authorization in RESTful services?
Note: I am implementing RESTful using Jax-RS (with Apache CXF implementation), helpful if you could explain with Jax-RS.
-Barath
Edit:
As Donal mentioned, I am not looking for role based authorization rather resource level authorization.
To give an example, lets say /users/{id}/photos/{photoId} be another resource url. User_1 should be given access to the photos belong to him only. If photoId of 2 belonging to user_2, then we should give http_404 error code for user_1 when a request /users/1/photos/2 is requested.[Since User_1 is also authenticated user he can invoke /users/2/photos/2, so we must identify the user id based on authentication parameters than via resource url]
Only solution I can think of is, include the unique id which determines the authorization in each query like,
Instead of SELECT * FROM PHOTO_TBL WHERE PHOTO_ID=2;
use SELECT * FROM PHOTO_TBL, USER_TBL WHERE PHOTO_ID=2 AND USER_ID=1 AND USER_ID=PHOTO_ID;
with this resources are delivering data that belongs to specific user. [There should be a mechanism to prevent the modification of the unique id in client side which is used to decide on authorization(userId in this case), since all requests are STATELESS request]
Caveat: Each and every query should be intelligent enough to understand the security concerns and include extra join. This is a bad design to tie up security logic to every business function.
I am yet to look into Spring security and how it can be used in this use case.
I would recommend not having the user id in the url (as if it's being 'limited' by a Basic Auth header then you may as well just have it 'specified' by the Basic auth header). This will reduce the risk of introducing a Direct Object Reference Vulnerability - https://www.owasp.org/index.php/Top_10_2010-A4-Insecure_Direct_Object_References)
In this case you could have one of the following urls:
/users/CURRENT
/me
As photos is a sub resource then you could just create the photos with a "sequence number" within the user. In a sql database this would mean having a "compound key" across both user and photo columns.
/users/CURRENT/photo/{user_photo_seq}
/me/photo/{user_photo_seq}
Your SQL would then look something like:
SELECT * FROM PHOTO_TBL WHERE USER_ID=<BasicAuthUsername> AND PHOTO_ID=<path param value>;
A good explanation of "Basic Auth Headers":
http://en.wikipedia.org/wiki/Basic_access_authentication
JAX-RS specifies sub-resource where instead of handling request in a method, processing is delegated to other object - sub-resource.
Using sub-resources it's enought to take care of the root resource and nested ones will be secured as well.
In the example you can see UserResource and all it's sub-resources available only to authorized user.
#Path("/user/{userId}")
public class UserResource {
private final String userId;
public UserResource(#PathParam("userId") String userId, #Context SecurityContext securityContext) {
this.userId = userId;
boolean authorized = /* authorization code */;
if (!authorized) { throw new WebApplicationException(Status.UNAUTHORIZED); }
}
#Path("photo")
public PhotoResource getPhotoResource() {
return new PhotoResource(userId);
}
}
public class PhotoResource {
private final String userId;
public PhotoResource(String userId) {
this.userId = userId;
}
#GET
public Response listAll() { /* ... */ }
#GET
#Path("{photoId}")
public Response present() { /* ... */ }
}