Authentification and security model in client/server aplications - security

I'm developing custom client/server application that requires client to log in with their username and password. The user accounts are not related to Windows/AD accounts in any way. After login, client application will request other services from server system.
My question is what is the best way to implement this? What kind of architecture would fit best here? I guess some kind of ticket/token authentication system needs to be implemented???
Thanks

You may in fact want to implement a system which passes "tickets" along between the different parts (login server, client, app server). This ticket will contain basic information such as the user ID (the username, the row id, etc). This ticket will either be encrypted with a secret key that the authorized servers share, or will be stamped with a hash of the ticket contents salted with a secret key that the servers share. The first way makes it possible for only the authorized servers to create and read the ticket, and the second way makes it possible for the authorized servers to verify that only the authorized servers could have created the ticket but permits anyone to read the ticket. All app servers will check the ticket (by attempting to decrypt it or by verifying that the hash matches) before proceeding with any actions that should be protected. If this is a web app, then cookies are a good place to store the ticket.

You haven't said much about your architecture, other than it is Client/Server, so I am assuming you're using some sort of forms designer like Windows Forms in VS. In these cases I have always used some form of database table authentication, as it is easy, simple to setup, and reasonably secure. You can even set up groups and roles this way, without much fuss.
Table: Users
Fields: UserID PK
Login Text
Password Text
...
Table: Roles
Fields: RoleID PK
Role Text
...
Table: UserRoles
Fields: UserID FK
RoleID FK

Related

How to link logged users to their data, retrieve and update them in MySQL table

This is the my web-app "User Settings" page.
I have simplified it to a minimum to better highlight the problem.
To authenticate users I use Auth0, I wanted to use the sub claim user_id to identify the users inside my MySQL database for update and retrieve user's info. Unfortunately the user_id is different for each provider, for example, if the same user with the same e-mail logs-in via Auth0 he gets a user_id if he does it via google he gets another one.
I thought about using email to link logged user to his info.
The problem is in my API. Before the change it was "localhost: 8080 / api / users /: id"
each time it created a new id and in any case it was impossible to recover the data of the single user. Now that I have replaced "id" with "email" my API has also changed in "localhost: 8080 / api / users /: johnsmith#xxx.com".
Before:
After:
In a few words, the request url on the client side has also changed.
I would like to make sure that the GET and PUT requests are made based on the e-mail of the logged user without going to modify the whole back-end.
Sounds like something is wrong with how you authenticate users. If you have multiple ways to authenticate a user, those methods need to be in a one to many relation with the user. For example each user has a list of auth-methods, and whenever an authentication is made you check your table of authentication methods and find the one user it maps to.
Im not sure if you are doing this yourself or if the framework you are using is handling that, but it sounds like you need to change the model to allow many Auth methods for a single account.
Also you could use email, but that is also an "old" way of uniquely identifying users almost every single person has multiple active email accounts nowadays, so you should also have a one-to-many relation for users to emails. What if the user has different email accounts for their Facebook and Google accounts?
See account linking here: https://auth0.com/docs/users/user-account-linking
It is dangerous to trust that the external providers are truthful about what email belongs to who. What if I open a new account using someone else's email on one of the providers? Then I can log into that users account in your application, which is a pretty big security risk.

Implementing login system in React.JS & Node.JS

I need to implement a login system in MERN stack in which there will be three types of logins.
1. Admin login
2. Student Login
3. Faculty Login
The admin login will have a pre defined username and password (say admin & admin#123 resp.) which can be changed if needed.The faculty and student will only be able to login if the admin adds new student or faculty from his dashboard.The student and faculty username will be the registration number from college and password will be the date of birth.
All the tutorials that i came across are on registration and authentication & since registration is not a part of this project, I'd like to know basically how i should go about with this feature.
I am using mongodb as the database.
You have multiple things going on here:
authentication: accepting and checking a username and password
authorization: once a user has authenticated herself, assigning her the appropriate privilege level (admin, faculty, student in your case).
registration: in your system only the admin can register new users. This is different from some systems, which permit self-registration. Yours does not, according to your requirements.
(Important security tip it's a seriously bad idea to use date of birth for a password. Why? if a cybercreep breaks into your database, he will have a list of names and dates-of-birth. Those are useful for stealing your users' identities. They are also considered personally identifiable information and so they're covered by by GDPR and the California Consumer Privacy Act. But you didn't ask about that.... )
Let's take your requirements one-by-one.
1-authentication. This is a simple username/password scheme. Use the passport module for that, with its local strategy.
2- Authorization. When you look up the user also look up her privilege level (again admin or faculty or student). Passport feeds your user a session cookie so they stay logged in.
Before you display any page or accept any API request or form-post from a user, check the authorization level. If the user is not permitted to use the particular feature, send back a 403 error message rather than showing the page or accepting the form.
3- Registration. You need a form for creating / replacing / updating / deleting users (called a CRUD form). This form must be accessible only to your admin.
By the way, all this happens on your node / express server. Your react client must simply pass along the passport-generated session cookie with every request, so the server can look up the user to retrieve the authorization.
Thinking about your requirements in this structured fashion should help you apply the stuff you learn from various online tutorials.

How risky is it to use email for custom sign in?

For a web application, where we need to store and manage users (SSO or openauth or what not is off the table), where we manage important business data, how risky is it to use an email address + password as the sign in?
For the last 15 years or so, encryption and protection techniques have improved, but we continue to use a proprietary user id, akin to using your bank card number for online banking; an id that will not be reused elsewhere. Customers and product owners are pushing to use email address because it is easier to remember.
I am concerned that there are a lot of websites that collect email + password pairs in order to use them to try to hack other sites; presumably asking you to sign up for an account for some humble service or other. What is this activity called?
I'm looking for some article or argument why using email+password for a site with sensitive business/financial information would be dangerous; or why it is not so bad. Again, I realize that provisioning our own accounts is not the ideal thing and am not looking for solutions at outsourcing authentication.
The "risk" of using a single authentication method for signing onto your application is difficult to determine without a risk assessment, and clearly defined system boundaries.
NIST 800-61 and NIST 800-63 gives guidelines on authentication methods for different levels of sensitive systems (in your case, a application). It will give you ideas on how to present your argument, and maybe an alternative solution, i.e., multi-factor authentication if the customer wants to authenticate using an e-mail address. This would mitigate the risk associated with malicious websites which collected e-mail addresses and passwords.
Keep in mind, password policy can also be managed to mitigate the risk behind a single authentication method using an e-mail and a compromised password associated with that e-mail.
All in all, it's not the ID that is important, but the authentication method and policies in place to mitigate the risks.
Using email + password as credentials is the widely accepted method of allowing users to log into sites on the web.
The advantage of using email is that everyone remembers their email address, whereas people will have difficulty in remembering which username or user ID they first signed up with if this is not their email address.
Username should not be considered private. This is the job of the password. Encourage your users to use a password manager such as LastPass where it can generate a 20 character completely random password (128 bits - uncrackable) which is different per site. LastPass will remember the username if this is not their email, so that solves this problem, however not using email can bring other problems such as username enumeration. If any signup function asks for a user to specify their username and you say that it is already in use, an attacker can use this to narrow the list of users in order to prepare for a password guessing attack. If you ask for email as step one of password reminder or signup forms, the system can send an email with a password reset link if already registered, or send an email with a link to the next step in the registration process if not.
In the end it all comes down to the value of the data your application is protecting. Adding two factor authentication is always a good step and can protect against password guessing and password reuse.
SSO or openauth or what not is off the table
Why is the case? Can't you use OAuth with claims based authorisation? You can still secure your application and make sure only the correct business users have access - it would just be that another entity is managing access for you.
I am concerned that there are a lot of websites that collect email + password pairs in order to use them to try to hack other sites; presumably asking you to sign up for an account for some humble service or other. What is this activity called?
Credential harvesting?

Cookie Security

I had a quick question about cookie security that I wanted to run by the stackoverflow community before I got too far into implementing it. This will be my first time implementing user sign-in on a site and I wanted to be extremely cautious about security so-as not to have to worry about accounts being compromised down the line.
Here's my hypothetical security solution:
User signs up for site (through either email registration, login with Facebook, etc.) and is assigned a User ID number. This number is public and can be used to access the profile of the user, refer to them in posts, and so on.
At registration, the user is also assigned a randomly generated ROWID as their information is stored in a database (hosted on Google Fusion Tables). This ROWID number is kept hidden from the user and is never revealed.
The User ID is encrypted against the ROWID number and this number is stored in a cookie on the user's computer. It isn't ever visible to other users and, in theory, this could only be viewed by the user.
This solution would allow for a "secret" key (the ROWID number), a "consumer" key (saved in the cookie), and a public reference ID (the User ID). All of these are, of course, rolled up into a database where the site can quickly access them. Does this sound like a plan that would provide the proper level of security or is there something else that I should consider?
For additional protection against cookie theft through something like XSS, you might want to consider issuing unique cookies per IP address, and then making sure that the cookies are only useable from that IP address.
If you're storing your cookies in the database, things can get complicated, as you now have multiple cookies mapping to the same user.
Here's how to avoid those problems:
Set-Cookie: userName=Alice; authCode=eeba95a4...
Where: authCode=HMAC(ROWID, userName + ipAddr)
When you receive this cookie, look up the user in the database, recompute/verify the authCode in the cookie, using ROWID and ip address of the request. No need to store cookies in the database.
For extra crypto points, throw a salt parameter into the mix:
Set-Cookie: userName=Alice; salt=59843...; authCode=eeba9...
Where: authCode=HMAC(ROWID, userName + ipAddr + salt)
Salt value is generated randomly for every cookie you produce. There's no need to keep it a secret.
This is a good question, and since you have no answers yet I will give it a go. As far as I can see (I'm not a cryptographic expert) this seems reasonable, at least in theory.
I see one problem, that is if a malicious user get the consumer key (and this is not protected in any way) he could try to brute force the ROWID since he already know the User ID. So at least some kind of salt should be added to the User ID before encrypting. Also the "consumer" key ccokie should be passed as secure only, making sure it never travels on an unencrypted connection.
But it all depends on what you are planing to use the different keys for.

How do you support a web app with hashed or encrypted passwords?

When supporting a new web app in an enterprise environment, it is often necessary to log in as a specific user in order to diagnose a real or perceived problem they are having. Two opposing issues apply here:
Best practice is to use hashed or encrypted passwords, not clear text. Sometimes, there is a third-party SSO (single sign-on) in the middle. There is no way to retrieve the user's password. Unless the user provides it (not encouraged), there is no way to log in as that user.
Many web app's have personalization and complex authorization. Different users have different roles (admin, manager, user) with different permissions. Sometimes users can only see their data -- their customers or tasks. Some users have read-only access, while others can edit. So, each user's view of the web app is unique.
Assume that in an enterprise environment, it isn't feasible to go to the user's desk, or to connect directly to their machine.
How do you handle this situation?
Edit: I want to reiterate that in a large financial institution or typical Fortune 500 company with hundreds of thousands of employees all of the country, and around the world, it is not possible for a mere developer in some IT unit to be able to directly access a user's machine. Some of those are public-facing web apps used by customers (such as online banking and stock trading). And, many of those are intranet applications rely on Active Directory or an SSO, meaning that user credentials are the same for many applications. I do thank you all for your suggestions; some may be highly useful in other kinds of environments.
A number of these ideas inconvenience the user, either by forcing them to change their password, or by occupying their desktop for your debugging session.
Markc's idea is the best: augment your authentication logic to allow superusers to log in as a particular user by supplying not the user's credentials, but the user's name plus their superuser credentials.
I've done it like this in the past (pseudo-ish python):
if is_user_authenticated(username, userpassword):
login the user
else if ':' in userpassword:
supername, superpassword = userpassword.split(':')
if is_superuser_authenticated(supername, superpassword):
login the user
In other words, if the username and password don't authenticate, if the password has a colon, then it's actually the admin username and admin password joined by a colon, so login as the username if they are the right admin username and password.
This means you can login as the user without knowing their secrets, and without inconveniencing them.
For our web applications we use a process that for lack of a better term is defined as 'hijacking' a user's account.
Basically, administrators can 'hijack' a user's account with a simple button click. In the code, you simply use a unique identifier (user id works in a less secure environment) that then establishes the necessary credentials in the session so that they can then work within that user's profile. For a more secure environment you could use a unique hash for each user.
In order to ensure that this hijack method is secure, it always first verifies that the request is being made by an authenticated administrator with the appropriate rights. Because of this it becomes necessary for either the administrator's session to be hijacked or for their authentication credentials to be captured in order for someone to ever exploit the hijack function within the application.
I had 4 ideas. While I was typing 3 of them were already suggested (so I upvoted them)
Variant on idea 3 - impersonation:
To make this as "identical as possible" to a normal login with minimal code changes, you might add the ability to impersonate directly at login by supplying Admin credentials plus an alternate username, e.g. login as Admin:user, adminpassword. The system would treat this exactly as logging in as user with userpassword.
Idea 4: Can you access the password store? If so, temporarily replace the user's hash with the hash of a known password. (the passwords are often stored online in a database. A SQL Query tool can do the swaps )
An administrator should be able to change a user's password. Change the password for the user to something you know. You can then log in as that user.
Tell the user to reset his/her password after you are done debugging.
Usually by some sort of remote control software that can be used to view their desktop. If they're on a Windows terminal server, then the built in admin tools can be used for that. Otherwise I'd use something like VNC across an internal network, or an external service like LogMeIn (http://www.logmein.com/).
Could you have a testing environment where there is a regular cut of live data copied to (obviously sanitised to meet any security or data protection issues). A user similar in setup to the one having trouble could be used to troubleshoot or indeed the very user if this is allowed.
Use a remote desktop client as mentioned in other answers, but again this may not be practical for you. If you have these rights within the domain, I have heard of error handling even doing a screenscrape and including this in logs! but this sounds a little odd to me.
Could you have an admin tool to clone a user into a demo account?
The solution we have used in our web apps is to have the authN/authZ return the desired user as the effective user. We do this by having an admin feature to setup a masquerade, and then when we ask for the currently logged in user (current_user), we handle the masquerade:
def current_user_with_effective_user
if masked?
current_user_without_effective_user.masquerade_as
else
current_user_without_effective_user
end
end
alias_method_chain, :current_user, :effective_user

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