I have 3 microservices that hold particular user information including their sign-in credentials (email + password). If the services are A, B, and C then the user "John" will have his info stored separately in all three of these services' database.
Now, the user info in service A is updated at an earlier point of time, and at that moment it is not predictable whether services B or C will definitely be activated to be used by that particular user. So, there is no point in creating an entry in B and C for "John". But, as "John" activates B or C at a later point of time, the system can only have access to the hashed password.
It is to be noted that the service C requires the password to be stored in encrypted form so that it can be decrypted later. So, merely storing the hashed value in all 3 services is not feasible, neither do we want all 3 of them to have encrypted password.
What is a feasible solution to sync the password between the services by maintaining the requirements?
Your approach implies a lot of problems in addition to the one you already described yourself. I recommend to look into Federated Identity (using OAuth2 and OpenID Connect) which fits for Microservices architectures.
Basically, this means that authentication and credentials handling is performed by a separate highly available and scalable service (usually referred to as identity provider or authorization server) that only does that - handling user credentials, identity and access control - and does it well.
It handles login and issues access tokens which are then sent to your Microservices along with the requests. As each Microservice will trust this identity provider it will be able to verify that the token is valid and was issued by this identity provider (this happens by validating the token with a public key). And the token contains information like user id and information about what actions are allowed with this token.
The identity provider can be a cloud service like Okta, Auth0, Azure AD B2C, etc. (see https://openid.net/developers/certified/#OPServices) or host an identity provider on your own, if you are not able to access cloud services, by using ready-to-use libraries available for your technology stack (https://openid.net/developers/certified/#OPLibs).
So there is no need to store user credentials in each Microservice and sync this information between them. I would consider such an approach as an anti-pattern.
The federated authentication approach also allows to solve other problems such as single-sign-on.
If you are new to that topic it can be a little overwhelming at first but it's something you can't get around if you really want to have all the advantages a Microservices architecture can provide.
This article might help you get started:
https://nordicapis.com/how-to-control-user-identity-within-microservices/
Related
So from what I have read on IdentityServer I should be storing details about the user such as first name and last name inside claims. How would a web application then be able to access the claim information? Since the User Info endpoint requires a valid access token representing the user, I suppose I would need to make an API that could access that returned the profile information of other users? Is this the right way to do it? (use case, web page needs to display contact details that are stored in claims of another user)
Also what would be the way for multiple language profile information be stored and retrieved in the claims? For example a user can have a name/title in multiple languages. I'm thinking of making [LanguageCode]_[ClaimType] (fr_first_name) naming convention and either adding all languages to just the profile IdentityResource or creating separate resources per language.
Your best bet is to set up a project using the IdentityServer4 QuickstartUI example and review that code to better understand how it all works. As of version 4, Identity Server is only focused on the sign-in / sign-out process and the various flows around authentication. They also provide a basic EF-driven persistence model, and they also support the ASP.NET Core Identity persistence model (also EF-driven), but both of those are not meant to be production-ready code.
Basically, persistence of user details is considered your responsibility. That being said, the cookies used for ASP.NET Core authentication greatly restricts how much data you can/should store as claims. The best model is to keep "real" identity provider (IDP) claims as claims, don't add new claims to that list, copy what you need into some other separate user-data table you manage completely, and use the unique claims identifier (almost always "subject id") as the key to your user data. This also makes it easier to migrate a user to another IDP (for example, you'll know user details for "Bob" but he can re-associate his user data away from his Facebook OIDC auth to his Google auth).
Basic persistence isn't too difficult (it's only 12 or 13 SQL statements) but it's a lot more than will fit in a Stackoverflow answer. I blogged about a non-EF approach here -- also not production-ready code (for example, it has ad-hoc SQL to keep things simple), but it should get you started.
Our application (referred to as "XYZ_App" below) is a multi-tenant SaaS application. We are in the process of making it available for Microsoft AppSource as a multi-tenanted "Web app / API" (referred to as "AppSourceXYZ_App" below).
We started our OpenID Connect implementation with endpoints pointing to “common” as per stated in the documentation when multi-tenancy is desired/required.
In XYZ_App, we added information in the system to know what AAD instance each XYZ_App tenant is associated with (using the GUID Microsoft assigned to this AAD instance, we are NOT using the "rename-safe.onmicrosoft.com" representation).
When using the “common” endpoints, we had to manually validate the issuer from the JWT to make sure it was the expected one: a user could access XYZ_App requesting access to XYZ_App’s tenant associated with contoso.onmicrosoft.com, get directed to “login.microsoftonline.com/common” to authenticate and then decide to authenticate with a user from another AAD instance (referred to as "anotherAADInstance.onmicrosoft.com" below). In this scenario, even though a user could successfully authenticate on anotherAADInstance.onmicrosoft.com, XYZ_App’s redirect URI must make sure the JWT issuer is the one from contoso.onmicrosoft.com. I’ll refer to this setup as Scenario_1.
With that scenario in mind, we thought about NOT using “common” and customize the requests going to login.microsoftonline.com on the fly; attempting to “jail” requests to be forced to authenticate against a specific AAD instance. We would still need to perform our validation in the redirect URI to make sure the issuer is the appropriate one, but we thought this approach might make our lives easier. I’ll refer to this setup as Scenario_2.
Do you envision Scenario_2 is viable in the long run or is it too short-sighted ? Based on my current knowledge of OpenID Connect, one limitation I can see with Scenario_2 is that it would become problematic to support “broker accounts” into our app.
Explanation of “broker accounts”: in our industry, some external users are allowed access to the system. Let’s say I have a company called “BrokerCo” (with their own brokerco.onmicrosoft.com AAD instance) who has 2 employees: Broker1 and Broker2. BOTH anotherAADInstance and contoso hired Broker1 and Broker2 to get broker services to perform tasks in XYZ_App; requiring XYZApp to grant them access. What is the ideal way for authentication from an OpenID Connect standpoint ? If XYZ_App were to use “login.microsoftonline.com/common” for authentication (like in Scenario_1; as opposed to “jailed” access like in Scenario_2), Broker1 and Broker2 could authenticate with brokerco.onmicrosoft.com (no AAD "External users" for anotherAADInstance nor contoso), but they would then get to redirect URI with an issuer that is different than what XYZ_App’s anotherAADInstance and contoso tenants are configured for... I feel like I’m back to square 1...
Do you have suggestions or pointers to solve this issue ?
Background context:
While playing with OpenID Connect issuers, I got the following error message:
AADSTS50020: User account 'testuser#anotherAADInstance.onmicrosoft.com' from identity provider 'https://sts.windows.net/XXXXXXXX-fake-GUID-9bZZ-XXXXxxxxXXXX/' does not exist in tenant 'XYZ Publisher' and cannot access the application 'YYYYYYYY-fake0-GUID-YYYYyyyyYYYY' in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account.
Thanks in advance !
Your question has multiple layers, trying to address most of them:
AppSource is about trial experiences for new users: this mean that any corporate account around the globe can potentially be an user of your SaaS application - or at least to the trial experience of your application, therefore the first thing you need to think when integrating with AppSource is how easy it has to be for a potential user to experience your app for the first time.
With that in mind, AppSource recommends that the trial of application is build on such a way that allows any user from any organization to sign-in, and therefore a multi-tenant approach for your application is the recommended setup for any application.
The single-tenant approach requires more control on your side, and for a trial experience - it means that the user cannot try your application right away because the operation you have to do on your single-tenant application is to add the user to an Azure Active Directory tenant as a guest user. This guest account will need then to wait receiving an email to accept the invitation to join to this tenant you are adding the user to then sign-in to your application.
Therefore your scenario 1 is the best scenario thinking on a trial experience in general, and also in general require less management (as you'd not need to create/ manage each individual account that needs to access your application as guest users of your Azure AD instance).
However some concerns you listed - that this scenario bringing are valid: Because you are accepting the common endpoint, you are saying basically that any user can sign-in to any tenant to your application, and this may not be desirable. In addition, the scenario you listed that a user can generate a token for any application is also valid, however, you can add additional checks to make this more secure and that any token generated by another authentication is blocked:
You can validate the 'audience' claim to guarantee that the token was issued to your application
You can eventually check the 'tid'/'iss' claims against of a list of tenant Ids in your database to see if that the user's organization is a valid organization in your application -- this would be valid for non-trial users/ organizations.
More information in this article.
About scenario '2' and broker accounts:
This scenario could be interpreted in two different ways:
Broker accounts are guest accounts of a customers' Azure AD tenant
Broker accounts are third party accounts but are not actually added as a user of anotherAADInstance or contoso AD
If your case is '1' then you're right: if your application needs to authenticate guest users that belong to another Azure AD tenant, then common endpoint could not be used directly.
If your case is '2' then what you'd need to do is to continue using the common endpoint and somewhat after the user is authenticated ask them to choose the company. I am describing this on generic terms without fully understanding this scenario. Perhaps this is not simple as you want the remote company to control this and not the user - so some additional complexities may need to be handled here.
A note is that if your scenario is scenario 1. - in theory - you can still use an hybrid approach, where you'd ask user to type the username inside the application and the company that they want to sign-in, then check if you need to validate the user against common or tenant-id endpoint, preparing the request and then sending a login_hint argument when authenticating. More information here
What's the best practice or the common way of keeping (or not keeping) Evernote users in your application's database?
Should I create my own membership system and create a connection to Evernote accounts?
Should I store Evernote user data (or only part of it) in my own app and let the user log in only with Evernote?
Summary: you must protect their data but how you protect it is up to you. Use the integer edam_userId to identify data.
I think the API License agreement covers protection in the terms:
you agree that when using the API you will not, directly or indirectly, take or enable another to take any of the following actions:...
1.8.4 circumvent or modify any Keys or other security mechanism employed by Evernote or the API;
If you cache people's data and your server-based app lacks security to prevent people looking at other's data, then I think you're pretty clearly violating that clause. I think it's quite elegantly written!
Couple that with the responsibility clause 1.2
You are fully responsible for all activities that occur using your Keys, regardless of whether such activities are undertaken by you or a third party.
So if you don't protect someone's cached data and another user is able to get at it, you're explicitly liable.
Having cleared up the question of your obligations to (as you'd expect) protect people's data, the question is how do you store it?
Clause 4.3 covers identifiers pretty directly although it's a bit out of date now that we are all forced to use oAuth - there are no passwords ever entered into anything other a web view. However, mobile or desktop client apps must provide a mechanism for the user to log out, which must completely remove the username and password from your application and its persistent storage.
For a web app, you can't even save the username: If your Application runs as an Internet service on a multi-user server, you must not ask for, view, store or cache the sign-in name or password of Evernote user accounts.
The good news is that you can rely on the edam_userId value which comes back to you in the oAuth token credentials response, as discussed here.
When you look at the Data Model, you can see the unique id under the User and going into the User struct, see the reassuring definition The unique numeric identifier for the account, which will not change for the lifetime of the account.
Thinking about the consequences, as you can't get the user id until you have logged into the service, if you want to provide a local login for people you will have to link your local credentials to the user id. That may irk some people if they have to enter a username twice but can't be helped.
You can allow users to log-in via OAuth. Here's a guide on how that process works.
But you'll probably also want to store a minimal amount of user data, at least a unique identifier, in your database so you can do things like create relationships between the user and their notebooks and tags. Refer to the Evernote data model for those relationships. If you're using rails, this will also help you take advantage of rails conventions.
I am looking for a way for two Google Apps applications to talk to each other and share data between each other. I have the following scenario:
Application A logs user in using Google Apps login
Application B logs user in using Google Apps login
then these applications need to communicate directly to each other (server-to-server) using some APIs
The question is: how do these applications verify that the other one is logged in with the same user to Google? I would imagine something like:
- Application A gets some 'token' from Google and sends it to Application B
- Application B verifies that this token is valid for the same Google account as it is logged in with
Is there a way to accomplish that via Google Federated Login? I am talking about Hybrid protocol here.
Here's a simple way to do it:
You keep everything keyed to the user's Google userid on both applications.
You share the data using HTTP requests that contain the userid.
To prevent leaking of the userids (forbidden by the account API) and to verify the messages really come from the other application, you encrypt the requests with a symmetric cipher such as AES or Blowfish or whatever you like. Both applications have the same key embedded.
You could public key cryptography. With just two applications, it's not worth it in my opinion. If you start having more apps, public key makes sense.
The fine print: encryption does not guarantee integrity or origin without additional measures. You need to take precautions against playback, for example by incorporating a time-stamp or sequence number. You need to take precautions against tampering, e.g. with a checksum. Make sure to use CBC and good initialization vectors. Keep the key secret.
user.user_id() is always the same across all the apps for the same user. So you can simply compare values returned by user.user_id(). Is this what you are looking for?
Note: Every user has the same user ID
for all App Engine applications. If
your app uses the user ID in public
data, such as by including it in a URL
parameter, you should use a hash
algorithm with a "salt" value added to
obscure the ID. Exposing raw IDs could
allow someone to associate a user's
activity in one app with that in
another, or get the user's email
address by coercing the user to sign
in to another app.
From docs
I am creating a web app that will use OpenID logins and OAuth tokens with Youtube. I am currently storing the OpenID identity and OAuth token/token secret in plain text in the database.
Is it inappropriate to store these values as plain text? I could use a one-way encryption for the OpenID identifier but I don't know if that is necessary. For the OAuth tokens, I would need to use a two-way encryption as my app relies on getting the session token for some uses.
Is it necessary to encrypt the OpenID identity? Could someone use it to gain access to a user's account?
First, there is a registered application that has consumer_key and consumer_secret.
When users authenticate and "allow" your registered application, you get back:
an access_token that is considered the user's "password" and would allow JUST YOUR application to act on the user's behalf.
So, getting just the user's access_token from your database won't help much if they don't also have the consumer_key and consumer_secret for complete access.
The service provider compares all 4 parameters on request. It would be smart to encrypt these 4 parameters before storage and decrypt them before response.
This is just when you need to update or make changes to the user's resource owner on behalf of a user. To keep a user logged-in on your site, use sessions.
The OAuth Token and Secret should both obviously be kept safe in your database, but you can't store them using 1 way encryption the same way you would for a password. The reason being is that you need the token and secret to be able to sign the request.
This would also be the case if you are running an OAuth server, you still need the original token/secret to verify the request.
If you want to you could still encrypt them using a 2 way encryption algorithm such as AES to offer security in case your database or database backups get compromised.
There's two schools of thought here.
The first argument is that: you should treat OAuth tokens like passwords. If anyone were to access your database, obtain all the OpenID/OAuth pairs and run an man-in-the-middle attack, they could impersonate any user on your site.
The second argument is this: by the time someone has access to your database and sufficient access to your network to run an man-in-the-middle attack, you're hosed anyway.
I'd personally err on the side of caution and just encrypt them; it's a standard practice for passwords, so you might as well give yourself just that little extra peace of mind.
Meanwhile, Google has this advice:
"Tokens should be treated as securely as any other sensitive information stored on the server."
source: http://code.google.com/apis/accounts/docs/OAuth.html
And some random guy on the web has specific implementation advice:
If they’re on a regular disk file, protect them using filesystem
permissions, make sure that they’re
encrypted, and hide the password well
If they’re in a database, encrypt the fields, store the key
well, and protect access to the
database itself carefully. *
If they’re in LDAP, do the same.
archived post (original post URL, now a dead link)
OpenID URL shouldn't be encrypted because this is your "open id" literally, everyone should know the value. Besides, the URL needs to be an index in the database and it's always problematic to encrypt the index in the database.
OAuth token/secret should be secret and encryption may improve security if you have to store the token long term. In our OAuth consumer application, token/secret is only stored in session for a short while and we choose not to encrypt them. I think that's secure enough. If someone can peek into our session storage, they probably have our encryption key also.
Yes, these should be symmetrically encrypted (say, AES-256 in CBC mode) at rest in a database. A simple way to encrypt these tokens is using SecureDB's Encryption as a Service RESTful APIs.
Disclosure: I work at SecureDB.