What I have right now?
I have a working SP-initiated flow where users can authenticate against their IDP. If they return after some time and click on SP-initiated authentication link, IDP lets them bypass entering credentials.
Question
Why does IDP decide to allow the user to jump over entering credentials? I have discovered if I delete my cookies this does not happen. Is this then IDP set cookie and IDP controlled session? Can I control this via SAML Request?
Can I enforce IDP to always ask for credentials by setting a FOO SAML Request flag? Is this even possible?
Most of the times the point of introducing SAML-based federated SSO is that users don't have to enter their credentials over and over again. So not having to type their credentials is a feature of the IDP.
But the behavior is completely up to the IDP who controls how and when the user authenticates. The SP can ask for forced authentication but it is still the IDP that decides if that request is honored (by following the spec).
An IDP may skip asking for credentials explicitly if the user has logged in explicitly within a short timeframe before the current authentication request. That's still relatively secure and convenient for the user.
you can force IdP to always prompt user for re-authentication by passing ForceAuthn=true attribute in authentication request.
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
Is it possible to force user to re-enter credentials in a SAML IDP after he has successfully login. This is part of the e-signature workflow where we want user to re-authenticate himself before continuing.
I am using keyCloak as IDP and to achieve this, in my SAML request I set ForceAuthn to true. Even though the flag is set to true, the IDP never asks user to provide credentials again. I believe its happening because there's a valid cookie available in the request.
The other option is to disable the Cookie "Authentication Flow" as shown in the image below (setting the first row in the grid as disabled), in which case the user has to provide credentials always.
So, Is it possible to keep Cookie "Authentication Flow" not disabled and yet force the user to provide credentials?
In SAML, is it possible to force the user to go through idp's login process everytime even when the user has an active idp session?
To make a concrete example here:
Let's call my application "SP"
I use SSOCirecle as idp and I use POST and redirect (SP initiated).
To test, I will first login to SSOCircle to get an active idp session. Then when I try going to SP, I should be redirected to idp.
Normally, since I already have an active idp session, the idp will see "oh, you already being authenticated before, you can go directly to SP!"
But I don't want that, I want idp to force the user to enter credential everytime, maybe by either (I guess)
ignore active idp session
don't create an idp session
I want to knwo whether this is doable.
Yes, the SP can send a flag ForceAuthn to the Idp in the AuthnRequest to require a new authentication instead of reusing an existing session.
As always with SAML2, you can't expect all Idps to support everything. Yyou have to test if your Idp supports the ForceAuthn flag.
I started with Service Provider based SSO for SAML. Since the user had to enter his email before proceeding with the login, a state variable was initiated and passed on to the SSO. It comes back through the callback URL and hence was check again for the sanity purpose. It protected against CSRF attacks.
Now IdP initiated SSO doesn't allow me to set state variable at all. Login starts at Identity Provider and only an auth token is provided to the app. I do not know which user is authenticating from the beginning. If I remove the state variable check, it could trigger a CSRF attack as well.
I am also using omniauth in rails which makes state variable a compulsory param and SSO provider is auth0.
What is the way to attach state variable to IdP initiated SSO solutions?
The de-facto standard value of the RelayState parameter in IDP-init-SSO SAML flows is the URL that you want to send the user to after successful validation of the SAML assertion at the SP. That would work for the vast majority of SAML deployments out there.
However, that mechanism indeed does not protect against CSRF attacks this is why the spec is silent on the value of RelayState in IDP-init-SSO and leaves it open to agree on mechanisms between IDP and SP to prevent CSRF through the value of that parameter. One such mechanism would be to use a signed value in the RelayState but as said, nothing is standardized and it would thus depend on a bi-lateral agreement between IDP and SP which does not scale.
In summary: send the value of the URL that you want the user to go to as the RelayState value in the "unsolicited" SAML Response that you send to the SP. How you get the IDP's SAML stack to do that is implementation specific. For Auth0 you can read on this at: https://auth0.com/docs/protocols/saml/saml-configuration#idp-initiated-sso, and in your case it would look like:
https://{accountname}.auth0.com/samlp/YOUR_CLIENT_ID?RelayState=http://FINAL_DESTINATION_URL
I am implementing a SSO using SimpleSAMLPhp Service Provider.
I provided my metadata to remote Shibboleth Identity Provider and was provided a test account.
When a user visits a specific page on my SP, they get redirected to the IdP, login, and are redirected back to my web site with a bunch of IdP provided attributes. This part works.
This part I am struggling with.
If the user authenticates with the same IdP through a different Service Provider and then visits my page, how do I know they are already authenticated? Currently I am being asked to login again.
Is there a configuration value somewhere that lets me do this? Or am I using the wrong method? This is what I am doing.
$as = new SimpleSAML_Auth_Simple({REMOTE_AUTHSOURCE});
$as->requireAuth(); // this redirects to remote IdP login
$attributes = $as->getAttributes();
Thanks.
There are two separate authentication sessions to consider. One session is in you app and the other is at the IdP. The requireAuth method can tell if the user already has an authenticated session in your application, and will return immediately in that case.
There is no way for you to tell if a browser has a session at the IdP. You just call requireAuth whichs send the user there and if the IdP decides the user's session is still valid it will respond without prompting for login.
Are you saying that the user has a valid session at the IdP and they are being re-prompted to authenticate when you send the user there? That could be due to IdP policy, or if your app was sending something like 'forceAuth' in its AuthnRequest.