Vuejs best practices for defence against interface attacks from editing state variables in browser - vue.js

Given something simple like this:
<Dashboard v-if="$store.getters.ui.user.role == 'staff'/>
<Dashboard v-if="$store.getters.ui.user.role == 'manager'/>
... what is the best practice for defending against someone changing user.role from 'staff' to 'manager' in the browser.
(Of course, data is loaded from the server based on role here, so at best the curious user will see an empty and slightly broken interface, but better if they see nothing at all). Other than obfuscation of the rather obv's user.role=='staff', I can't see any way around it.

There is no way to prevent a user from being able to change the client-side code provided to him. The solution you mentioned is the right approach. Never trust the user with any sensitive data unless verified by your server.
This means that while a user with bad intentions might be able to change his role to "manager" and thereby get access to the dashboard (or even remove the if-statement only rendering the Dashboard conditionally - the code is there), the dashboard he sees cannot contain any sensitive data only supposed to be visible to users with a "manager" role.
The key is not providing the user any data he is not supposed to see in the first place, not obfuscate the data passed in hopes the user won't notice. You are not protecting against the average user but rather somebody who knows how to code and has the intention of breaking your application. Obfuscated code is a small hurdle and not sufficient to prevent attackers from seeing and understanding the underlying logic.

Related

UML: is this use case true for a user authentication?

I'm make a use case for a user authentication for a website, and when the user register a new account the website send a verification email to the user.
Is this use case correct? If not, how can I improve it?
This is the use case I made:
This diagram is syntactically wrong: the dashed lines should be arrows which are either «includes» or «extends» to explain the dependencies between use cases.
Semantically the diagram could be correct (depending on how you decide for the dependencies) with the following remarks:
The actor service must be an external autonomous system and not an internal verification service in the same system.
The use cases shall be independent and have no order between them. Hence, are you sure it’s ok to first login and then register?
Breaking a functionality (e.g. registration) down into smaller ones (e.g. send email) is called "functional decomposition". Although it is not forbidden by UML, it is not recommended by practitioners, as it leads to overly complex diagrams.
The key issue with this diagram is purpose: despite the many bubbles, we still don't know what the goals of the actors are, nor what the purpose of the system is. But this is what use cases should tell us. supposed t. Use case should focus. Login and registration are not really goals: they are just a necessary step to do something more meaningful.
In short, the diagram is correct, but it is also true that it depends on the level of detail you want to go into with the UML diagram. Generally, in the case of login or registration, we tend to represent more in detail. For example credential check, password recovery and other events.

Best way to log usage in VB.NET? (To a server)

I have an application but for security reasons I need to keep track of who uses it. It will be used in my company and the users will be informed that their usage will be tracked. This is because it's dealing with some sensitive information so we need to know who has accessed it.
That said, I don't know how to approach this in a secure way. The simplest way would simply be to write computer name, Ip, etc etc to a text file and upload it to a FTP file server. However for this to be possible, I need to include the authentication details in the code which, if decompiled or otherwise seen would be very dangerous.
So I was wondering if there's any good/decent approaches to doing this in VB.NET?
Thanks.
In my project i used DBManager class where i did all my DB stuff, so to keep track of what users are doing, I wrote an function that fired up every time Data was edited, inserted, deleted etc, or even User has logged in, my function Inserted new data with query (what user has done), username, date, IP and so on...
It's not perfect, but it worked and I think this method is worth to recommend.

REST API responses based on authentication, best practices?

I have an API with endpoint GET /users/{id} which returns a User object. The User object can contain sensitive fields such as cardLast4, cardBrand, etc.
{
firstName: ...,
lastName: ...,
cardLast4: ...,
cardBrand: ...
}
If the user calls that endpoint with their own ID, all fields should be visible. However, if it is someone elses ID then cardLast4 and cardBrand should be hidden.
I want to know what are the best practices here for designing my response. I see three options:
Option 1. Two DTOs, one with all fields and one without the hidden fields:
// OtherUserDTO
{
firstName: ...,
lastName: ..., // cardLast4 and cardBrand hidden
}
I can see this becoming out of hand with DTOs based on role, what if now I have UserDTOForAdminRole, UserDTOForAccountingRole, etc... It looks like it quickly gets out of hand with the number of potential DTOs.
Option 2. One response object being the User, but null out the values that the user should not be able to see.
{
firstName: ...,
lastName: ...,
cardLast4: null, // hidden
cardBrand: null // hidden
}
Option 3. Create another endpoint such as /payment-methods?userId={userId} even though PaymentMethod is not an entity in my database. This will now require 2 api calls to get all the data. If the userId is not their own, it will return 403 forbidden.
{
cardLast4: ...,
cardBrand: ...
}
What are the best practices here?
You're gonna get different opinions about this, but I feel that doing a GET request on some endpoint, and getting a different shape of data depending on the authorization status can be confusing.
So I would be tempted, if it's reasonable to do this, to expose the privileged data via a secondary endpoint. Either by just exposing the private properties there, or by having 2 distinct endpoints, one with the unprivileged data and a second that repeats the data + the new private properties.
I tend to go for option 1 here, because an API endpoint is not just a means to get data. The URI is an identity, so I would want /users/123 to mean the same thing everywhere, and have a second /users/123/secret-properties
I have an API with endpoint GET /users/{id} which returns a User object.
In general, it may help to reframe your thinking -- resources in REST are generalizations of documents (think "web pages"), not generalizations of objects. "HTTP is an application protocol whose application domain is the transfer of documents over a network" -- Jim Webber, 2011
If the user calls that endpoint with their own ID, all fields should be visible. However, if it is someone elses ID then cardLast4 and cardBrand should be hidden.
Big picture view: in HTTP, you've got a bit of tension between privacy (only show documents with sensitive information to people allowed access) and caching (save bandwidth and server pressure by using copies of documents to satisfy more than one request).
Cache is an important architectural constraint in the REST architectural style; that's the bit that puts the "web scale" in the world wide web.
OK, good news first -- HTTP has special rules for caching web requests with Authorization headers. Unless you deliberately opt-in to allowing the responses to be re-used, you don't have to worry the caching.
Treating the two different views as two different documents, with different identifiers, makes almost everything easier -- the public documents are available to the public, the sensitive documents are locked down, operators looking at traffic in the log can distinguish the two different views because the logged identifier is different, and so on.
The thing that isn't easier: the case where someone is editing (POST/PUT/PATCH) one document and expecting to see the changes appear in the other. Cache-invalidation is one of the two hard problems in computer science. HTTP doesn't have a general purpose mechanism that allows the origin server to mark arbitrary documents for invalidation - successful unsafe requests will invalidate the effective-target-uri, the Location, the Content-Location, and that's it... and all three of those values have other important uses, making them more challenging to game.
Documents with different absolute-uri are different documents, and those documents, once copied from the origin server, can get out of sync.
This is the option I would normally choose - a client looking at cached copies of a document isn't seeing changes made by the server
OK, you decide that you don't like those trade offs. Can we do it with just one resource identifier? You immediately lose some clarity in your general purpose logs, but perhaps a bespoke logging system will get you past that.
You probably also have to dump public caching at this point. The only general purpose header that changes between the user allowed to look at the sensitive information and the user who isn't? That's the authorization header, and there's no "Vary" mechanism on authorization.
You've also got something of a challenge for the user who is making changes to the sensitive copy, but wants to now review the public copy (to make sure nothing leaked? or to make sure that the publicly visible changes took hold?)
There's no general purpose header for "show me the public version", so either you need to use a non standard header (which general purpose components will ignore), or you need to try standardizing something and then driving adoption by the implementors of general purpose components. It's doable (PATCH happened, after all) but it's a lot of work.
The other trick you can try is to play games with Content-Type and the Accept header -- perhaps clients use something normal for the public version (ex application/json), and a specialized type for the sensitive version (application/prs.example-sensitive+json).
That would allow the origin server to use the Vary header to indicate that the response is only suitable if the same accept headers are used.
Once again, general purpose components aren't going to know about your bespoke content-type, and are never going to ask for it.
The standardization route really isn't going to help you here, because the thing you really need is that clients discriminate between the two modes, where general purpose components today are trying to use that channel to advertise all of the standardized representations that they can handle.
I don't think this actually gets you anywhere that you can't fake more easily with a bespoke header.
REST leans heavily into the idea of using readily standardizable forms; if you think this is a general problem that could potentially apply to all resources in the world, then a header is the right way to go. So a reasonable approach would be to try a custom header, and get a bunch of experience with it, then try writing something up and getting everybody to buy in.
If you want something that just works with the out of the box web that we have today, use two different URI and move on to solving important problems.

In IdentityServer4, how do you securely store the ReturnUrl?

I am developing an identity server 4 dotnet core application so this is as much as a dotnet question than and IDS4 question. One example of state I need to maintain between pages (login, signup etc...) is the returnUrl. The application I'm migrating from used to store it in a session variable but, as I understand, unless I run a persistent session strategy, this won't scale well.
So currently, I'm passing it around as a field in each View Model used by each view so it can be returned. Is this a sound approach? I'll be needing other fields to be passed around as well so I'm wondering whether this is a secure and logical way to do it.
So currently, I'm passing it around as a field in each View Model used by each view so it can be returned. Is this a sound approach?
Yes, how you choose to pass it around is up to you, I choose this same approach. You could use TempData, Sessions or even localStorage as an alternative. I think having it in the models (view models) is a good approach because you are explicitly specifying where you want the return url to exist, otherwise it might persist in context that you wouldn't want.
Now the security question because obviously you might be able to see the return url in the browser address field.
As part of Identity Server 4 setup you specify which return url's you are allowed to redirect back to, so I don't think there is any harm in having the users see the redirect url.
Something to consider is what if the user would share the url to someone else in the middle of the authentication process, would they be able to resume from that part of the process that the initial user has stopped? is this something you want in your app?
If you mean reliably instead of securely, write tests which will provide you with confidence that your code works.

writing SEO-friendly pages that can be toggled public or private

our application wants to be able to create static, searchable pages based on user profile information, which would be linkable to other public profiles.
I am looking at LinkedIn as an example...it seems like they actually auto-generate the page to be a static file that is indexable and searchable.
Can someone suggest how we would do this? I am thinking there would need to be a cron job that runs and writes a the path and file name.
The user may want to keep the whole page private, in which case I imagine it would need to delete it.
There's alot of sub-requirements but that's the general concept and wanted to start getting ideas and feedback.
Thanks.
You can do without the cron job if you generate the static pages in real time whenever the profile information is created/updated or whenever user changed the setting to keep info public/private. This way you are not constantly looping through all users, and do not depend on another component (your cron job) to be running.
One alternative would be to adopt an explicit RESTful information architecture so that a profile resource ("page") is addressable with a permanent URL. The resulting resource could be a static page. Or not. That would be an implementation detail invisible to the search engine crawler and any web browser accessing the resource.
umnik700's answer is fairly dead-on if you're not considering issues related to authentication or who gets to see what. Consider the difference between the profiles you see when you're logged into Facebook versus those same profiles' publicly facing, searchable counterparts. Even MySpace, with a lot less consideration for search engine privacy, has viewability that is dependent on your relationship to the other person, defaulting, for private profiles, to "This profile has been set to private by the user" or something to that extent.
If you're looking to suddenly scale out a social tool where individuals are eliciting their personal information, I would suggest umnik700's answer (dynamically generate the content, but not the URLs, for public versions of the profile) with the following corollary: you need to be able to support privacy preferences varying from extremely strict to completely open, and default to a version that at least errs on the stricter, more private version of the profile. If you're just now pushing out searchable personal content when there never was any way to find it outside the site before, it's important not to abuse information given under different pretenses.
I know this probably requires maybe more scalability and added functionality than you were hoping this project would take, but to do otherwise could be most likely taken as a violation of your user base's tacit trust. Anyway, the best strategy to do this will probably require you to lean on your database more anyway, so it might be time to rework it a bit--including adding some privacy preferences.