I have a scenario where I have four to five web based application, which needs to have a common centralized authentication system, in this case how feasible is the SAML based approach i.e each time user want to access any of these web application the user is redirected to SAML server which in return redirects to the IDP, or is their some better solution for such architecture as I am new to the this domain
What you describe is exactly what SAML is designed to solve.
The user is normally only redirected to the SAML Identity Provider (Idp) on the first access to an application (a service provider (SP)). When the user is successfully authenticated by the Idp, the SP sets a cookie in the user's browser to handle authentication of subsequent requests.
Related
I have two service providers set up with one IdP and users are required to be authenticated twice to access both services at the same time. From my point of view, this is not "SSO" and I am thinking that there might have been settings done incorrectly and I would like to see if the community here can provide me with directions and/or possible solutions.
Just a thought - the behaviour for the authentication on each service looks valid as I understand that IdP is required to send signed SAML assertions to the providers in order to access the services. However, because I only have one IdP, can I not be authenticated just once and be able to access all the services?
Any suggestion is appreciated. Thanks.
Typically in this scenario the user would authenticate once to the IdP when the first SP SSO's to it. There would be no authentication at the IdP when the second SP SSO's to it as there's already an authentication session at the IdP for the user.
However, there might be use cases where you want the user to be authenticated at the IdP even if they already have an authentication session. The SP can set the ForceAuthn flag in the SAML authn request sent to the IdP. This requests that the IdP authenticates the user regardless of whether or not they already have an authentication session.
ADFS also has a configuration option for relying parties (SPs) to always require authentication. Take a look at the AlwaysRequireAuthentication flag.
https://learn.microsoft.com/en-us/powershell/module/adfs/set-adfsrelyingpartytrust?view=windowsserver2022-ps
I am implementing front-channel SAML 2.0 SSO golang Service Provider, with Okta as my Identity Provider (this is just a POC and should eventually work with any IdP).
Implementing the sign on process was straightforward with saml2 package. I've created the login endpoint that redirects to the SAML application login URL at the intended IdP, as well as the POST callback endpoint which is properly receiving the SAML assertion and is able to validate it. After that a session with a random cookie is created with the same TTL as the Identity Provider session TTL. So far everything works well (I haven't implemented Single Sign-Out yet, but I'm planning to).
However, when some time passes and the session expires, I'd like to renew it only if the user is still logged in with the Idp and hasn't been removed from the SAML Application. I would like to avoid redirecting the user to perform SSO again with IdP, because it would mean that if they are still logged in, they would be redirected back to the home page of my application. I wasn't able to find great sources on my options to go about it online.
Questions:
1.1 One solution that comes to mind is storing the requested URL in the RelayState parameter, whenever the session has expired, then redirect the user to the IdP SSO URL. When the redirect returns to the SAML callback POST endpoint, check the RelayState parameter and if set, redirect back to that (original) URL. That means that for users that use the system continuously, I would have to request Assertions very often. Does that make sense?
1.2 A second solution that comes to mind is to implement a back-channel of communicating directly from my SP to the IdP. That would allow me to verify a user is still logged in 'behind the users back'. If that's a sound idea:
a. Do I need to have dedicated code for each IdP?
b. Do I need to load an API key to the IdP which would allow secure communication?
c. Do I need to upload a public certificate to the IdP that would be able to verify that my SP signed the requests?
Will using the Assertion to get an OAuth 2.0 Access Token help me in achieving this?
I've chosen SAML 2.0 for now, since the environment is an enterprise oriented one and I thought it fits well with it based on what I read. Would using OpenID Connect instead help achieve my goals easier and fit well with enterprise oriented products?
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.
Let's say we have a service provider app called A hosted on tomcat, a user clicks a link to the SP A. SP A sees no token is provided so it redirects the user to the IdP for authentication (with a SAML Authn request provided by some means). The IdP then redirects the user to some common login page where credentials are provided, assuming that these credentials are correct the IdP creates a SAML response with a token and some assertions about the subject, and sends it back to SP A. SP A sees this and allows the user access into the application. Great!
I have a few questions though
How is the authorisation request/response sent, I understand there is a redirect binding and a POST binding where the SAMLResponse and request are encoded either as a query param, or sent as an XHTML form in case of a POST binding. But I'm not sure which is used where?
A service provider is the thing providing a service, so Office 365 or Sales force for example. Is each one a separate service provider? I ask as I watched a video where the guy said the service provider was the thing that hosted these services, so I'm not sure of the correct answer here?
How is the token stored on the client side? So for example I am now authenticated against SP A, the user then tries to use SP B from the same machine/browser window, how does SP B and the IdP know that the user has already authenticated and therefore doesn't need to re-authenticate. I.e. the SSO aspect of it.
Does SP B need to be hosted on the same tomcat instance for this to work?
I dedicated significant time to get SSO working for me. The most helpful document was this specification
The answers below are based on this experience:
Redirect or Post binding is used depending on a respective HTTP request header. The Post binding is recommended since it does not imply restrictions on data volume transferred.
A Service Provider in this context is anything that clients request. There may be many of them, participating in the same SSO scheme.
The service providers must be SSO-aware, which includes handling of the authentication response data. Usually you don't have to implement the protocol - there are ready-made frameworks that your SP can utilize.
Service Providers may reside on different servers.
From my own experience:
You choose your own SAMLBinding (redirect or post) depending on what your idp and sp supports. This binding type will be used both for the 1st step (SP -> Idp) and 2nd step (IdP -> SP). If you have some running environment, open your browser devtools and look at network tab to see what happens. It's just a way to send data from browser to SP/IdP.
Both Office 365 and Salesforce.com are cloud services, right? Let's take Office 365. it means that beyond "end-user" services (like Word, Excel) there is some technical SSO service which are common to the platform. It can be viewed as lower (or technical) service layers, I think that what you speaker meant.
The SAML token is stored by you SP application inside your browser, either hidden inside web page, cookie or web storage. It depends on how your SP is implemented.
SAML response can be validate by each SP based on shared private key, so it will decrypt the token using this key and be able to grant user without the help of IdP redirection.
Tomcat have some extension to support SAML. But SAML is designed to work without being on the same instance, as the opposite as basic JSESSIONID cookies.
So you have several instances, of course.
Method 1
Browser is directed to Service provider. Service provider checks whether there is any cookie set, If no then it redirects browser to Identity provider and Identity provider(IdP) validates user and redirect a ID to Service Provider(SP). SP takes that ID and set it as session cookie in browser and redirects user to service. Next time, if user asks for service again in same session the SP checks for cookie and redirects directly to service.
Method 2
Browser is directed to Service provider. Service provider redirects to IdP. IdP checks for its cookie and if cookie is not present,IdP authenticates user and set session cookie in browser. Redirects positive response to SP. SP redirects user to service. Next time user asks for the service within the session, Browser is directed to Service provider. Service provider redirects to IdP.IdP checks for its cookie and if it is present,it sends positive response to SP.
I am pretty sure that Guanxi implementation of Shibboleth (SAML2 profile) and almost sure that Shibboleth itself can be simplified to your "method 1".
You better check some of existing SAML2 profile implementations.
I don't believe either of those are valid SAML implementations. Usually in SAML identity information is communicated in a HTTP POST or through SOAP web service (see: http://en.wikipedia.org/wiki/Security_Assertion_Markup_Language#SAML_2.0_bindings). Cookies are not used to 'authenticate' a user.
We have a web application that uses SAML 2.0 XML communicated in a HTTP POST to authenticate the user. Our customer's employees go through the identity provider on their side of the firewall to access our application.