Forum Discussion
Failed authentication with SAML Certificate
I have verified the expiration date. The certificate is neither near expiration nor it has expired.
I am not testing immediately, but even after a few hours, I have to re-upload the certificate to my service provider, then I am able to authenticate the user.
If using multiple environments (e.g., testing, staging, production), ensure that all environments are using the same certificate, miss match certificates in different environments can cause unexpected login failures.
I have checked the sign-in logs and none of the logs indicate the InvalidSignature or CertificateRevoked issue.
Narrowing down the list of possible solutions. Do we have more suggestions/recommendations?
Check if your Service Provider (SP) automatically fetches metadata updates from Azure AD or requires manual refreshes. Some SPs require manual updates for any changes, including certificate renewals.
Try updating the metadata XML file in your SP settings after the initial SAML configuration to ensure there’s no caching or synchronization delay.
Did this ? In Azure AD, under Enterprise Application > Single sign-on settings, check if you have the option to enable Certificate Rollover.
Some Service Providers cache metadata or certificates. If the SP is caching the certificate, it may not be picking up changes immediately. Clear the SP’s cache, or if your SP supports a “refresh” or “reload” metadata feature, use it to ensure the latest Azure AD certificate is being recognized.
Go to Azure AD > Enterprise Applications > Your Application > Single sign-on > SAML-based Sign-on and verify if there are multiple certificates listed (e.g., primary and secondary).
If SAML assertions are encrypted, ensure that both the encryption and signing certificates are up-to-date and correctly configured. Sometimes mismatches occur between the two, causing authentication issues.
Please also double-check that the signing certificate matches the encryption expectations of your SP, and update the SP with both certificates if needed.
Also if you have access to logs on the SP side, enable detailed SAML logs. This could reveal whether the issue is related to certificate validation, metadata synchronization, or another problem.
Also Look for specific errors or timeouts in the SP logs around the certificate validation steps. Errors such as cert_not_valid, unable_to_retrieve_metadata, or signing_cert_mismatch can provide clues.
If Possible: Set up a temporary test instance of your application (or use a testing environment) and apply the same SAML settings. This will help isolate whether the issue is specific to the current SP configuration or an underlying Azure AD sync issue. If the test environment does not face the same issue, this suggests a configuration or caching problem specific to your SP environment.
Also recheck Azure AD Synchronization/Latency Issues.
If this problem persists, you might consider automating the certificate re-upload process as a temporary workaround using Azure AD APIs or scripts (similar to the PowerShell script provided earlier).
By scheduling this update periodically (e.g., weekly or monthly), you can avoid frequent manual interventions while investigating the underlying issue.
But if these steps don’t provide a resolution, I recommended to open a support ticket with Microsoft for a deeper investigation.