vCloud SAML authentication – Automation

Cant say that I did everything by my self in this post, I had a great great help from my college and friend Kasper Hansen. Also gotten a great help from the vExpert community, especially Tom Fojta.

In my last post I found out how to setup vCloud SAML against AzureAD. Now we are gonna look on how to automate each tenant to use the same AzureAD. In these days everybody have either a Microsoft og AzureAD account, so this way its easy to invite them as guest users and this way have controlled access but also ensure that vCloud users have MFA enabled.

We use VRO for the creation of vCloud tenants, in this flow we are now going to introduce a new workflow that will do following. Although the workflow is just a restcall to trigger an event in Azure Automation.

  • Create AzureAD Groups for admin and viewer
  • Post federation metadata to vCloud tenant
  • Post federation groups to vCloud tenant

Enable SAML

Fojta have some very good articles on his blog on the basic setup of SAML to different IDP systems. I also did a piece on it where Azure where the IDP provider.

Because we want to have all organisations linked to the same SAML app in Azure we need to have the same SAML certificate on all organisations. You can only do this with the API, but what the documentation did not say was that the certificate needs to be trusted by the keystore, the java keystore of the cells.

Create a self-signed certificate and make vCloud trust it

These commands will help you create a certificate and a private key in the needed pkcs8 format and certificate in the x509 format.

When you have done the new self-signed certificate you need to import it to each and one of your cells. After import you will need to restart the cells. One of the errors I did here way that I tried to import a .pem where the private key and certificate where combines, that won’t work. Only import the certificate.

Publish federation settings to API

We where having a lot of trial and error in this step, because that vCloud did not trust the certificate. Each time a put where done to the API the log complained. /opt/vmware/vcloud-director/logs/vcloud-container-debug.log it showed “Failed to generate keystore | requestId=<id>,request=PUT.”

Following is a example done in PowerShell, insert your self-signed certificate where it says —–END/BEGIN CERTIFICATE—–

Publish SAML groups to API

Now that the SAML metadata/certificate is uploaded and in place we need to add groups to tenant. You can read more about what groups/users should be imported in my other SAML blog post.

Each tenant have its own role ids, so when doing automation with group import we need to query the vCloud API and get the role ids. There is a specific query API to get data. When using a system account we need to specify a “VCLOUD-TENANT-CONTEXT” in the header of the request. This we we can query a tenant context from a system account.

After we got the role id we can now send up the group together with the role id and this was be able to authenticate based on a SAML group from AzureAD.

Conclusion

Now we have all the pieces for making automation where we can enable a tenant for SAML authentication and afterwards import f.eks. a viewer and admin group. External users will then be invited to the AzureAD, imported into the right group and now they have access to the their tenant. We can help the organisation secure the access to their virtual datacenter with MFA and they will have single sign-on with there own user that originates from their own AzureAD or Microsoft account.

A service library will be made where users can be invited to the tenant organisation. So that when one user have been invited that user will be able to invite its colleagues.

vCloud SAML authentication

vCloud have LDAP, SAML and local users as an option for tenant authentication. In this post, we are looking into SAML integration. With AzureAD.

The cool thing about AzureAD is that you will gain the MFA option out of the box, and when tenants want access we can also invite them from their own AzureAD tenant into the resource AzureAD tenant. This gives flexibility and overview of who has access.

ADFS is also an option, but there you need to keep your own infrastructure with a resource AD/ADFS and furthermore need a 3. party MFA solution.

Process:

  • Setup Enterprise app in desired resource AzureAD
  • Setup claims
  • Set federation entity id for tenant
  • Import vCloud federation metadata to AzureAD
  • Import AzureAD enterprise app federation metadata to vCloud
  • Setup allowed users/groups in vCloud

AzureAD

Let’s get started with Azure AD configuration. Login to your AzureAD portal https://portal.azure.com. Navigate to “Azure Active Directory” > “Enterprise App” and press “New Application”. Choose “Non-gallery application”. Give it the name “vCloud SAML test” and press “Add”. This will take a couple of minutes.

Navigate back to “Enterprise Apps” > “All applications” and choose your newly created App.

For test purpose, add/assign a test user to the app. This is under “Users and groups”. This user will be able to login to the enterprise app with AzureAD.

Now go to “Single Sign-on”. This will now ask for the sign-on method, and here we will choose “SAML”. This will then take us to the SAML setup. The first thing to do is importing the metadata from the cloud.

You will find the metadata by logging in to vCloud, go to the tenant, under “administration” > “federation” tab. Enter the URL for the tenant as a entity id, apply and afterwards download the metadata from the link.

You will find the metadata by logging in to vCloud, go to the tenant, under administration choose the federation tab. Enter the URL for the tenant as a entity id, apply and afterwards download the metadata from the link.

In azureAD “Upload Metadata” and chose the downloaded file from vCloud. This will give AzureAD the knowledge of where to redirect and accept request from.

vCloud can validate a couple of user/group parameters. Vmware documentation. So we will add some claims to Azure AD.

Now we will need to download the AzureAD metadata and import into vCloud. Fetch the data by pressing “Download” to the “Federation Metadata XML”.

Head over to vCloud tenant federation page again. Paste the content from the download metadata file. check the “Use SAML identity” and apply. Now we are almost ready to try it out. But first, head over to “Users” tab in vCloud. We need to add the user/role to whom are allowed to gain vCloud Access.

Here we put in the mail address and role of the user from Azure AD. When the SAML response then returns to vCloud then vCloud can see it been authenticated in Azure AD and that the user is an Org admin.

Next step would be to use groups and roles so that we can put users into groups in Azure AD and that way manage access for the tenant. But after this, we can now head to the tenant URL. We will then be redirected to the Azure AD login page, login and accept to MFA so that we can be redirected to our vCloud tenant.

And voila, we have logged into our vCloud tenant with Azure AD.

Troubleshooting:

When I first started this project I was using a GUID as a vCloud entity id. That meant that I could get it to work with ADFS but not AzureAD. I went full mole on the troubleshooting.

In the end, I intercepted the SAML responses. These are encoded in base64, easy task to decode. And afterwards, I got the XML that either ADFS or AzureAD is sending back. I could then compare them, and I saw som <ds> tags to the cert that wasn’t on in the response from AzureAD. Unfortunately, that was a duck and meant nothing.

By tailing the log from vCloud, tail -f /opt/vmware/vcloud-director/logs/vcloud-container-debug.log, I could get some hints when the SAML auth failed.

org.opensaml.common.SAMLException: Local entity is not the intended audience of the assertion in at least one AudienceRestriction

doing a bit more googling and found out that I should be looking at the <audience> tag from the two SAML responses. And yes, that made some sense.

Azure AD sets the value of this element to the value of Issuer element of the AuthnRequest that initiated the sign-on. To evaluate the Audience value, use the value of the App ID URI that was specified during application registration.
Like the Issuer value, the Audience value must exactly match one of the service principal names that represents the cloud service in Azure AD. However, if the value of the Issuer element is not a URI value, the Audience value in the response is the Issuer value prefixed with spn:.

https://stackoverflow.com/questions/38978298/azuread-jwt-token-audience-claim-prefix-makes-jwt-token-invalid

And that was the problem, spn: prefix when not using a URL as entity id. Changing it to the URL made it work.

Maybe this is obvious to the world, but I didn’t know it, but glad my troubleshooting skills where sufficient 🙂