Basic clarification regarding SAML - saml

I need to implement a SAML based authentication module and I am looking for answers to some basic question related to SAML. I tried searching for answers but couldn't find detailed information.
Resources to be protected is a SaaS based web application. Design I have received require4s building an authentication module using OpenAM, Ping, etc. Any access to web application will get authenticated through authentication system via SAML.
Questions that I have in this regard are:
If I understand correctly, SAML request contains a username. When someone first access web application, application has no information about user, how will it generate an SAML request then?
Once a SAML response is received by application, do subsequent access of web application by user also need to be routed and validated via authentication system?
Web application can interact with other sub-systems via web services or api calls. How can authentication context be passed to those systems.

No, the AuthnRequest does not have to contain a user name. It may, but in most cases it doesn't.
No, once the SAML response is received, the application typically set a cookie to create a local session.
The SAML Assertion can be passed to other services that the application uses. This is a non-trivial setup, but possible.

Related

SAML web server not part of the domain

My web application is running on server(cloud) which is not part of my domain. I want to implement SAML based login to the web application with my domain(Intranet machines).
Is it allowed? If it is, any special configuration needs to be done?
Is it allowed?
yes
If it is, any special configuration needs to be done?
You need to implement/use a SAML Identity Provider.
In general SAML was designed as a Single Sign On technology for web-based applications without the use of cookies. You may only use so called 'front-channel' bindings (like HTTP REDIRECT and HTTP POST) to transmit the SAML messages between the SAML Service Provider and the Identity Provider if the Service Provider can not communicate with the Identity Provider.

verify login+password in Perl via SAML

Is there a possibility to verify login+password in Perl via SAML at an Identity Provider (IdP)? If yes: how?
I am aware that this is not the usual way for SAML to work.
The background to this is that we have 4 different clients for our web application, which is supposed to enable a central password via SAML, which are implemented in completely different technologies.
Our product manager has decided that a SAML connection is too complex for the 4 clients and that authentication should therefore take place centrally in the web application.
The clients transfer login and password to the web application, just like without SSO, and the web application is supposed to verify the access data centrally.
Question 1: Is there a possibility to verify login+password in Perl via SAML at an Identity Provider (IdP)? If yes: how?
Answer:
Definitely No, from the cybersecurity perspective.
Question 2: I am aware that this is not the usual way for SAML to work.
Answer:
Yes. You are correct.
(I) The SAML specification defines three roles: a user, an identity provider (IdP), and a service provider (SP). In the primary use case addressed by SAML, a user requests to access a service or log in to a web application from a service provider. The service provider requests and obtains an authentication assertion from the identity provider. On the basis of this assertion, the service provider can make an access control decision for the user, that is, it can decide whether to allow the user to access the service or log in to a web application.
(II) Before delivering the subject-based assertion to the SP, the IdP may request some information from the user (such as a user name and password) in order to authenticate the user. SAML specifies the content of the assertion that is passed from the IdP to the SP.
(II.a) In SAML, one identity provider may provide SAML assertions to many SPs.
(II.b) Similarly, one SP may rely on and trust assertions from many IdPs. This will be the SAML scenario of your web application if your product manager decided to request all 4 different clients of your web application to develop their own SAML IdP. For example, some social websites allow their users to log in to their web account through identity authentication provided by the third-party IdPs such as Google, Facebook, LinkedIn via OAuth 2 protocol or OpenID Connect protocol/OAuth 2 (instead of SAML).
Question 3: The background to this is that we have 4 different clients for our web application, which is supposed to enable a central password via SAML, which are implemented in completely different technologies.
Answer:
If 4 different clients for your web application are supposed to enable a central password via SAML, they can implement their own SAML IdP in completely different technologies or programming language such as Java, PHP, or Scala.
(I) For example,
We developed our former version of Zero-Password Authentication and Authorization System in Java and leveraged Java-based Shibboleth IdP to provide SAML SSO for enterprise applications.
We developed our current version of Zero-Password Authentication and Authorization System with scalability and high availability in Scala to provide SAML SSO natively for enterprise applications without Shibboleth IdP.
(II) No matter which technology or programming language are used by 4 different clients of your web application to implement their own SAML IdP, their SAML IdP only needs to authenticate their users using a central password data store/repository (such as OpenLDAP or MySQL) locally and then deliver the user info using SAML assertion/SAML response to your web application/SAML service provider. Your web application/SAML service provider just needs to map the user info carried by SAML assertion to a local user info of your web application.
Question 4: Our product manager has decided that a SAML connection is too complex for the 4 clients and that authentication should therefore take place centrally in the web application.
Answer:
If the user identity authentication needs to take place centrally in your web application instead of in the SAML IdP, then 4 different clients do NOT need to implement their own SAML IdP from the cybersecurity perspective.
Instead you just need to create and assign different sub-domain to all 4 different clients, that is, all 4 different clients of your web application access different sub-domain, such as client-org1.your-web-app.com, client-org2.your-web-app.com, client-org3.your-web-app.com, client-org4.your-web-app.com.
Note that different sub-domain of your web application displays the same login webpage. Example #1: client-org1.box.com, client-org2.box.com if your clients also subscribe Box account, or Example #2: client-org1.my.salesforce.com, client-org2.my.salesforce.com if your clients also subscribe Salesforce account.
Question 5: The clients transfer login and password to the web application, just like without SSO, and the web application is supposed to verify the access data centrally.
Answer:
Different sub-domain of your web application displays the same login webpage.
4 different clients of your web application access different sub-domain of your web application, users of 4 different clients submit their login and password to your web application (through different sub-domain URL), just like without SSO, and the data store/repository of your web application is supposed to verify the access data (i.e., login username/password) centrally. Then 4 different clients of your web application do NOT need any SAML IdP.

Pass SAML response from a Web App to the REST API for authentication?

We have a Web App using REST API. The REST API is based on Loopback and uses it's built-in token-based authentication. For the Web App we use forms based authentication over HTTPS, so the user has to enter his username and password which we then use to get access token from the REST API via POST /users/login endpoint.
One of our customers asked us to support single sign-on (SSO) authentication through SAML 2.0 and AD FS.
We configured our Web App as a service provider (Relying Party in AD FS) and managed to support SSO for it. The changeling part is the authentication between Web App and the REST API. The idea right now is to configure both Web App and the REST API as the same Relying Party and add new POST /users/saml-login endpoint to the REST API, so the Web App can send a SAML response to that end point and get an access token based on the claims specified in the SAML response. Everything else should work as it used to work before. Here is the flow I imagine:
Web App generates SAML request and redirects a user to the IdP login page
After a successful login the user is redirected back to the Web App with the SAML Response
Web App acts as a proxy and redirects the SAML Response to the REST API endpoint (POST /users/saml-login) where it is validated
If the SAML response is valid the API returns an access token based on the claims
Web App uses access token for further communication with the REST API same as before
Here is the question: Is it OK to implement SAML-based SSO this way? Do you see any issues or security considerations with this approach? Are there any alternatives?
I have read a lot of articles on the web and questions here on StackOverflow about how to use SAML & REST API together:
Propagate SAML Assertion Response/Security Context to downstream Services/Apps
REST API authentication with SAML
SAML and back-end REST service authentication
Attacking SSO: Common SAML Vulnerabilities and Ways to Find Them
None of them really helped me to confirm or reject the idea described above.
That sounds like a reasonable approach. I can't think of any security issues.
You're simply re-posting the SAML response internally within your application for processing. As long as you then perform the various security checks on the SAML response and assertion within your REST API, there shouldn't be any issues.

Configure Okta to handle SAML authentication on behalf of our non-saml web app?

Our company maintains a Web App composed of a front-end and a back-end in (Node.js), and we support the standard username/password login authentication. A couple of our partners have requested we support SAML SSO, so their end-users can access our web app through a link on their respective portals without the need to login again.
Question: Do we need to turn our app into a full-fledged service provider (SP) by implementing a SAML sdk/library in our front-end and back-end?
Or is it possible to use a 3rd party authentication provider like Okta to handle the SAML nitty-gritty behind the scenes and then redirect the end user to our app, with possibly a token (JWT?) so we can retrieve the user info from Okta?
I've read everything I could find on Okta's site, and here, and couldn't find a definitive answer, either yes it's possible (with example) or no you can't do that.
Like you already mentioned in your question, there are 2 possible ways to do it.
Update your application to support SAML login flow with your app as SP, in which case you will not need to use any 3rd party auth provider
If you don't want to get into the SAML nitty-gritty, you can use a 3rd party provider like Okta as an intermediary that will consume the SAML responses from the IdP (used by your external customers) and then convert that assertion into an Open ID token (JWT). In this case, Okta will act as an IdP (Authorization server) to your web app and generate ID tokens.
Your app will then need to implement the Open ID connect login flow.
You can refer to http://developer.okta.com/code/javascript/okta_sign-in_widget_ref for this.

How do I integrate my web app with One Drive so that users don't have to log in twice?

We want to deeply integrate OneDrive with our web app in order to handle document and storage data. However, we want the users not to log in twice. I'm not sure whether this is possible, but I've been reading about SSO and SAML and it seems like it's the way to go.
Is it possible, and if so, is Single Sign On the way to go?
Single Sign-On (SSO) is a great solution for user experience when web applications are hosted on different domains. SAML as a standard was developed for cross domain authentication to solve this use case. You will need an Identity Provider (IdP) server that handles authentication of users to your web application and then the IdP Server issues SAML assertions to your web application and OneDrive. Your application in this architecture will be a Service Provider (SP) that will consume SAML assertions, as well as OneDrive is a SP that consumes SAML assertions. There are a number of SSO/Federation vendors that provide the IdP Server.
As far as implementation, once you have chosen and installed the IdP Server, you will need to implement your web application to consume the SAML assertion and configure the IdP Server as a connection. OneDrive will simply be a configuration as it already supports SAML and WS-Federation.
In addition to SAML as a protocol, there are other standards with respect to SSO/Federation such as OpenID Connect (OIDC) and OAuth2. When choosing a IdP Server solution you may want to look at these other protocols that can solve additional use cases. SAML works well for web applications and the use case you have described. OIDC and OAuth2 are better suited for secure APIs and native mobile applications.
Another consideration when looking at an IdP Server is how authentication is to be performed. Options for authentication could be using Kerberos/IWA if all clients are on a common domain, or authentication using a Login Form. You may also want to look at MFA support when looking at an IdP Server as part of the SSO solution.