CAS 6.6.x SAML delegated authN to Okta not working

[Yan Zhou]

 Hi there, 

When CAS is the SAML2 IDP, I am able to run a client app authenticating successfully.  But have trouble when CAS delegates authN to Okta (cas is set up as a SP in Okta)

 Client app runs on localhost:8081,   CAS 6.6.x runs on localhost:8443, delegate to Okta SAML2 IDP.  

Here is my problem, i likely misunderstood how delegated authN should work, but do not know how.

 When go to client:  localhost:8081, redirects to: http://localhost:8081/saml/login?idp=https%3A%2F%2Flocalhost%3A8443%2Fidp

 Redirects to:  https://localhost:8443/cas/idp/profile/SAML2/POST/SSO

 I would expect Okta login page comes up, but I am getting CAS error page that says: page Not found, I did not see any error in cas log.

 

In Okta, i configured my local CAS as a SAML 2.0 application

==================================================

SSO URL:  https://localhost:8443/cas/login

Audience URI:   https://localhost:8443/cas/idp

 

 cas.properties

==============

cas.authn.pac4j.saml[0].keystorePath=file:///C:/apereocas66x/config/casas-samlsp/samlkeystore

                <== i do not see keystore being created, why is this not created?

cas.authn.pac4j.saml[0].keystorePassword=changeit

cas.authn.pac4j.saml[0].keystoreAlias=cas-samlsp

cas.authn.pac4j.saml[0].privateKeyPassword=changeit

cas.authn.pac4j.saml[0].serviceProviderEntityId=http://localhost:8081/saml/metadata

                <== same SP entity ID when CAS was the IDP itself, without delegated authN

cas.authn.pac4j.saml[0].clientName=bootsp2

cas.authn.pac4j.saml[0].forceAuth=false

cas.authn.pac4j.saml[0].passive=false

cas.authn.pac4j.saml[0].maximumAuthenticationLifetime=1209600

cas.authn.pac4j.saml[0].serviceProviderMetadataPath=file:///C:/apereocas66x/config/spmetadata/1005-metadata.xml

                <== same SP meta data when CAS was the IDP itself, without delegated authN

cas.authn.pac4j.saml[0].identityProviderMetadataPath=https://dev-11792448.okta.com/app/exkas4vj25jdUfJEx5d7/sso/saml/metadata

cas.authn.pac4j.saml[0].destinationBinding=urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST

cas.authn.pac4j.saml[0].userNameQualifier=false

 

 

JSON file in service registry

======================

{

  "@class" : "org.apereo.cas.services.CasRegisteredService",

  "serviceId" : "bootsp2",

  "name" : "bootsp2",

  "id" : 1005,

  "description" : "sample",

  "attributeReleasePolicy" : {

    "@class" : "org.apereo.cas.services.ReturnAllowedAttributeReleasePolicy",

    "allowedAttributes" : [ "java.util.ArrayList", [ "name", "first_name", "middle_name" ] ]

  }

}

thanks,

Yan

[Ray Bon]

Yan,

Is it possible that the okta-cas config is incorrect and okta is returning an error response which cas does not understand?

Are you using SAML Tracer to see the exchanges between SPs and IdPs?

If the keystore is not created, you can create it yourself. Or, turn off SAML encryption between SPs and IdPs.

Ray

On Fri, 2023-08-11 at 13:42 -0700, Yan Zhou wrote:

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[Yan Zhou]

i think i am missing something fundamentally, but I do not know what it is.

I first excluded the dependency on cas-server-support-saml-idp because CAS is delegating authN to Okta, I realize the login page does not even come up, nothing shows in SAML Tracer.   Then, I added this dependency, see below.

    implementation "org.apereo.cas:cas-server-support-saml-idp:${project.'cas.version'}"
    implementation "org.apereo.cas:cas-server-support-pac4j-webflow:${project.'cas.version'}"

Now the login page comes up, and I can see authN request coming to CAS, but I do not see how CAS delegates authN.  It seems that something is missing so that CAS is -not- generating SP meta data, which it should. Not sure what I am missing. 

I based on cas.properties from the following documentation, but it is not working, i.e., nothing is being generated by CAS, no error, either. 

in delegated AutN, when client come to CAS, which then delegate to Okta, should /cas/idp/profile/SAML2/POST/SSO be called at all?

# Settings required for CAS SP metadata generation process # The keystore will be automatically generated by CAS with # keys required for the metadata generation and/or exchange. # # cas.authn.pac4j.saml[0].keystorePassword= # cas.authn.pac4j.saml[0].privateKeyPassword= # cas.authn.pac4j.saml[0].keystorePath= # The entityID assigned to CAS acting as the SP # cas.authn.pac4j.saml[0].serviceProviderEntityId= # Path to the auto-generated CAS SP metadata # cas.authn.pac4j.saml[0].serviceProviderMetadataPath= # cas.authn.pac4j.saml[0].maximumAuthenticationLifetime= # Path/URL to delegated IdP metadata # cas.authn.pac4j.saml[0].identityProviderMetadataPath=

[Ray Bon]

Yan,

I was browsing the docs and 

cas.authn.pac4j.saml[0].serviceProviderMetadataPath

cas.authn.pac4j.saml[0].serviceProviderEntityId

are for cas as a service provider metadata, not the destination application.

https://apereo.github.io/cas/6.6.x/integration/Delegate-Authentication-SAML.html

Ray

[Yan Zhou]

Thanks Ray,   making some progress, I now see the SP Meta data and keystore being generated.

for delegated AuthN, here is the SAML request from my client app, it goes to CAS, the authN request seems correct.

<saml2p:AuthnRequest xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" AssertionConsumerServiceURL="http://localhost:8081/saml/SSO" Destination="https://localhost:8443/cas/idp/profile/SAML2/POST/SSO"

................... > <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">http://localhost:8081/saml/metadata</saml2:Issuer>

But then I run into error in CAS,  it is stilling loading IDP functionality and tries to find the client in service registry, this is where I do not understand how SAML delegated authN works different from CAS as IDP itself.

this is my service definition as CAS documentation says.

{
  "@class" : "org.apereo.cas.services.CasRegisteredService",
  "serviceId" : "bootsp2",
  "name" : "bootsp2",
  "id" : 1005,
  "description" : "sample",
  "attributeReleasePolicy" : {
    "@class" : "org.apereo.cas.services.ReturnAllowedAttributeReleasePolicy",
    "allowedAttributes" : [ "java.util.ArrayList", [ "name", "first_name", "middle_name" ] ]
  }
}

2023-08-15 09:30:23,875 WARN [https-jsse-nio-8443-exec-9] [org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController] - <[http://localhost:8081/saml/metadata] is not found in the registry or service access is denied.>
2023-08-15 09:30:23,875 WARN [https-jsse-nio-8443-exec-9] [org.apereo.cas.util.function.FunctionUtils] - <screen.service.error.message>
org.apereo.cas.services.UnauthorizedServiceException: screen.service.error.message
        at org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController.verifySamlRegisteredService(AbstractSamlIdPProfileHandlerController.java:172) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController.verifySamlAuthenticationRequest(AbstractSamlIdPProfileHandlerController.java:490) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController.initiateAuthenticationRequest(AbstractSamlIdPProfileHandlerController.java:315) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController.lambda$handleSsoPostProfileRequest$4(AbstractSamlIdPProfileHandlerController.java:652) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.util.function.FunctionUtils.lambda$doAndHandle$9(FunctionUtils.java:330) ~[cas-server-core-util-api-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.support.saml.web.idp.profile.AbstractSamlIdPProfileHandlerController.handleSsoPostProfileRequest(AbstractSamlIdPProfileHandlerController.java:653) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at org.apereo.cas.support.saml.web.idp.profile.sso.SSOSamlIdPPostProfileHandlerController.handleSaml2ProfileSsoPostRequest(SSOSamlIdPPostProfileHandlerController.java:74) ~[cas-server-support-saml-idp-web-6.6.9.jar!/:6.6.9]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]

[Yan Zhou]

on my client side where it loads IDP xml, what should SSO URL be, when CAS delegates SAML authN to Okta?

 

<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://localhost:8443/cas/idp/profile/SAML2/POST/SSO"/>

- this results in error on CAS, it tries to load from service registry, matching SAML Service, which is not the case in delegated authN

OR

<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://localhost:8443/cas/login?client_name=bootsp2"/>

- this matches in error on CAS, 

2023-08-15 10:30:16,666 ERROR [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager] - <Delegated client identifier cannot be located in the authentication request [https://localhost:8443/cas/login?client_name=bootsp2]>
2023-08-15 10:30:16,667 ERROR [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.actions.DelegatedClientAuthenticationAction] - <
DefaultDelegatedClientAuthenticationWebflowManager.java:retrieveSessionTicketViaClientId:236
DefaultDelegatedClientAuthenticationWebflowManager.java:retrieve:84
DelegatedClientAuthenticationAction.java:restoreAuthenticationRequestInContext:285
>
2023-08-15 10:30:16,667 WARN [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.actions.DelegatedClientAuthenticationAction] - <>
org.apereo.cas.services.UnauthorizedServiceException:
at org.apereo.cas.web.flow.actions.DelegatedClientAuthenticationAction.restoreAuthenticationRequestInContext(DelegatedClientAuthenticationAction.java:292) ~[cas-server-support-pac4j-webflow-6.6.9.jar!/:6.6.9]
at org.apereo.cas.web.flow.actions.DelegatedClientAuthenticationAction.populateContextWithService(DelegatedClientAuthenticationAction.java:205) ~[cas-server-support-pac4j-webflow-6.6.9.jar!/:6.6.9]
at

[Yan Zhou]

It is finally working after debug Source code, I am so grateful with open source,  here is the key.

thanks Ray!

on CAS side, the generated sp-metadata.xml says:          

        <md:Extensions xmlns:init="urn:oasis:names:tc:SAML:profiles:SSO:request-init">
            <init:RequestInitiator Binding="urn:oasis:names:tc:SAML:profiles:SSO:request-init" Location="https://localhost:8443/cas/login?client_name=bootsp2"/>
        </md:Extensions>

But, on my client, where I specify IDP XML, it needs to use CAS_CLIENT_ID, as opposed to client_name,    Does anyone know why?

<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://localhost:8443/cas/login?CAS_CLIENT_ID=bootsp2"/>
<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="https://localhost:8443/cas/login?CAS_CLIENT_ID=bootsp2"/>

here is CAS client definition json.

=============================

{
  "@class" : "org.apereo.cas.services.CasRegisteredService",
  "serviceId" : "^(https?|imaps)://.*",

  "name" : "bootsp2",
  "id" : 1005,
  "description" : "sample",
  "attributeReleasePolicy" : {
    "@class" : "org.apereo.cas.services.ReturnAllowedAttributeReleasePolicy",
    "allowedAttributes" : [ "java.util.ArrayList", [ "name", "first_name", "middle_name" ] ]
  }
}

SSO URL, if I use:  https://localhost:8443/cas/login?client_name=bootsp2,   got this error (it cannot find the matching, i have to use CAS_CLIENT_ID as parameter name, then it will work.).

2023-08-15 11:25:01,951 DEBUG [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager] - <Client identifier could not found in request parameters. Looking at relay-state for the SAML2 client>
2023-08-15 11:25:01,951 DEBUG [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager] - <Located delegated client identifier []>
2023-08-15 11:25:01,952 ERROR [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager] - <Delegated client identifier cannot be located in the authentication request [https://localhost:8443/cas/login?client_name=bootsp2]>
2023-08-15 11:25:01,955 ERROR [https-jsse-nio-8443-exec-4] [org.apereo.cas.web.flow.actions.DelegatedClientAuthenticationAction] - <>
org.apereo.cas.services.UnauthorizedServiceException:
at org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager.retrieveSessionTicketViaClientId(DefaultDelegatedClientAuthenticationWebflowManager.java:236) ~[cas-server-support-pac4j-core-6.6.9.jar!/:6.6.9]
at org.apereo.cas.web.flow.DefaultDelegatedClientAuthenticationWebflowManager.retrieve(DefaultDelegatedClientAuthenticationWebflowManager.java:84) ~[cas-server-support-pac4j-core-6.6.9.jar!/:6.6.9]
at 

DefaultDelegatedClientAuthenticationWebflowManager: it is looking for CAS_CLIENT_ID_SESSION_KEY in request parameter.

===================================================

protected String getDelegatedClientId(final WebContext webContext, final Client client) {
var clientId = webContext.getRequestParameter(PARAMETER_CLIENT_ID)
.map(String::valueOf).orElse(StringUtils.EMPTY);
if (StringUtils.isBlank(clientId)) {
if (client instanceof SAML2Client) {
LOGGER.debug("Client identifier could not found in request parameters. Looking at relay-state for the SAML2 client");
clientId = webContext.getRequestParameter(SamlProtocolConstants.PARAMETER_SAML_RELAY_STATE)
.map(String::valueOf).orElse(StringUtils.EMPTY);
}
}

clientId = getDelegatedClientIdFromSessionStore(webContext, client, clientId, OAuth20Client.class, OAUTH20_CLIENT_ID_SESSION_KEY);
clientId = getDelegatedClientIdFromSessionStore(webContext, client, clientId, OidcClient.class, OIDC_CLIENT_ID_SESSION_KEY);
clientId = getDelegatedClientIdFromSessionStore(webContext, client, clientId, OAuth10Client.class, OAUTH10_CLIENT_ID_SESSION_KEY);
clientId = getDelegatedClientIdFromSessionStore(webContext, client, clientId, CasClient.class, CAS_CLIENT_ID_SESSION_KEY);

LOGGER.debug("Located delegated client identifier [{}]", clientId);
return clientId;
}

If you know whether I missed anything, I would love to know.  I still do not understand why I cannot just use client_name in SSO URL parameter on client side.

thanks,

Yan