RE: CAS 5 SAML2 Azure AD delegated authentication

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Dickison, Lynn E

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Aug 7, 2018, 9:53:27 AM8/7/18
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I saw on another posting that someone else was trying to do delegated authentication using ADFS.  They were able to get it to work using CAS 5.2, but it didn’t work with CAS 5.3.  Since ADFS and Azure AD are both Microsoft products, I decided to try out delegated authentication to Azure AD using CAS 5.2.  Lo and behold, IT WORKED!  CAS 5.2 produces a SAML authentication request that Azure AD considers valid.  Here is the comparison of the two:

 

This one is from CAS 5.3.2, which DOES NOT work Azure AD SAML authentication:

 

<?xml version="1.0" encoding="UTF-8"?>

<saml2p:AuthnRequest

        AssertionConsumerServiceURL="https://xxxxxxxx.yyyyyyyyyyyyy.edu:8443/cas/login?client_name=SAML2Client0"

        AttributeConsumingServiceIndex="0"

        Destination="https://login.microsoftonline.com/cad830e4-554f-4361-bae5-c865233fb77f/saml2"

        ForceAuthn="false"

 ID="_2nqagio59j7csvzqzu0mynfr4tsbfqzhnlleupl"

        IsPassive="false"

        IssueInstant="2018-08-02T21:50:33.174Z"

        ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"

        ProviderName="pac4j-saml"

        Version="2.0"

        xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol">

    <saml2:Issuer

            Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity"

            NameQualifier="https://xxxxxxxx.yyyyyyyyyyyyy.edu"

            xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">

        https://xxxxxxxx.yyyyyyyyyyyyy.edu

    </saml2:Issuer>

</saml2p:AuthnRequest

 

This one is from CAS 5.2.6, and DOES work with Azure AD SAML authentication:

 

<?xml version="1.0" encoding="UTF-8"?>

<saml2p:AuthnRequest

        AssertionConsumerServiceURL="https://xxxxxxxx.yyyyyyyyyyyyy.edu:8443/cas/login?client_name=SAML2Client"

        AttributeConsumingServiceIndex="0"

        Destination="https://login.microsoftonline.com/cad830e4-554f-4361-bae5-c865233fb77f/saml2"

        ForceAuthn="false"

        ID="_3r88plxbege1ozzotobvkeqihy3x2jrk4sok94r"

        IsPassive="false"

        IssueInstant="2018-08-06T21:19:34.731Z"

        ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"

        ProviderName="pac4j-saml"

        Version="2.0"

        xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol">

    <saml2:Issuer

            xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">

        https:// xxxxxxxx.yyyyyyyyyyyyy.edu

    </saml2:Issuer>

</saml2p:AuthnRequest>

 

The highlighted lines are the only ones I noticed that were different in the format of the CAS 5.3.2 vs. CAS 5.2.6 SAML authentication requests.

 

Can anyone tell me if there is a configuration setting that I can change in CAS 5.2.3 that will make this work successfully?

 

Lynn Dickison

Missouri State University

 

 

 

From: cas-...@apereo.org <cas-...@apereo.org> On Behalf Of Dickison, Lynn E
Sent: Thursday, August 2, 2018 5:07 PM
To: cas-...@apereo.org
Subject: [cas-user] CAS 5 SAML2 delegated authentication

 

I’m trying to set up CAS 5.3.2 so that it delegates authentication to Azure AD via SAML2.  I’ve seen documentation on how to delegate authentication to an external SAML2 IdP, and I’ve read the tutorial (https://apereo.github.io/2017/03/22/cas51-delauthn-tutorial/).  The tutorial showed how to set it up with Okta as the IdP, and I’m assuming that works.  However, Azure AD gives me an error message that the authentication request is not a valid SAML2 protocol message.

 

Here is the configuration I have in the cas.properties file:

 

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

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

cas.authn.pac4j.saml[0].keystorePath=file:/etc/cas/saml/samlKeystore.jks

cas.authn.pac4j.saml[0].keystoreAlias=********

 

cas.authn.pac4j.saml[0].serviceProviderEntityId=https://xxxxxxxx.yyyyyyyyyyyyy.edu

cas.authn.pac4j.saml[0].serviceProviderMetadataPath=file:/etc/cas/saml/xxxxxxxx.xml

 

# Path/URL to delegated IdP metadata

cas.authn.pac4j.saml[0].identityProviderMetadataPath=file:/etc/cas/saml/AzureADCAS.xml

 

 

Here is an example authentication request that Microsoft says is valid in their documentation:

 

<samlp:AuthnRequest

        xmlns="urn:oasis:names:tc:SAML:2.0:metadata"

        ID="id6c1c178c166d486687be4aaf5e482730"

        Version="2.0" IssueInstant="2013-03-18T03:28:54.1839884Z"

        xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">

    <Issuer xmlns="urn:oasis:names:tc:SAML:2.0:assertion">https://www.contoso.com</Issuer>

</samlp:AuthnRequest>

 

 

Here is an authentication request generated by CAS via pac4j:

 

<?xml version="1.0" encoding="UTF-8"?>

<saml2p:AuthnRequest

        AssertionConsumerServiceURL="https://xxxxxxxx.yyyyyyyyyyyyy.edu:8443/cas/login?client_name=SAML2Client0"

        AttributeConsumingServiceIndex="0"

        Destination="https://login.microsoftonline.com/cad830e4-554f-4361-bae5-c865233fb77f/saml2"

        ForceAuthn="false" ID="_2nqagio59j7csvzqzu0mynfr4tsbfqzhnlleupl"

        IsPassive="false"

        IssueInstant="2018-08-02T21:50:33.174Z"

        ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"

        ProviderName="pac4j-saml"

        Version="2.0"

        xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol">

    <saml2:Issuer

            Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity"

            NameQualifier="https://xxxxxxxx.yyyyyyyyyyyyy.edu"

            xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">

        https://xxxxxxxx.yyyyyyyyyyyyy.edu

    </saml2:Issuer>

</saml2p:AuthnRequest>

 

Here is the error message I’m getting from Azure:

 

Request Id: 75ca32eb-47cb-426a-992d-ee70fc6a1b00

Correlation Id: 996cb2e6-b6b3-4077-abaa-a76e2578255a

Timestamp: 2018-08-02T21:50:33Z

Message: AADSTS75005: The request is not a valid Saml2 protocol message.

Advanced diagnostics: Enable

If you plan on getting support for an issue, turn this on and try to reproduce the error. This will collect additional information that will help troubleshoot the issue.

 

Root cause: Azure AD doesn’t support the SAML request sent by the application for Single sign-on. Some common issues are:​​

·         Missing required fields in the SAML request​​

·         SAML request encoded method​

 

 

If anyone has been able to get SAML2 delegated authentication working with Azure AD as the IdP, or if you know why it won’t work, I would appreciate any information you can supply.

 

 

Lynn Dickison
Senior Enterprise Systems Administrator
Computer Services

Missouri State University
901 S. National Ave.
Springfield, MO 65897
Phone: 417-836-4515 | Fax: 417-836-3192
lynndi...@missouristate.edu | www.missouristate.edu

Missouri State University: Make Your Missouri Statement

 

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Dmitriy Kopylenko

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Aug 7, 2018, 11:53:22 AM8/7/18
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You could try cas.authn.pac4j.saml[0].useNameQualifier=false

Best,
D.
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Dickison, Lynn E

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Aug 7, 2018, 3:59:00 PM8/7/18
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That’s a good idea, but cas.authn.pac4j.saml[0].useNameQualifier=false isn’t a valid configuration option in CAS 5.3.2.  When I put that into the cas.properties file, CAS doesn’t start.

 

Lynn Dickison

Dmitriy Kopylenko

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Aug 8, 2018, 9:02:58 AM8/8/18
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