modern apps
129 TopicsAnnouncing the reliable web app pattern for .NET
Reliable web app pattern is a set of best practices built on the Azure Well-Architected Framework that helps developers successfully migrate web applications to the cloud and set a foundation for future modernization in Azure.55KViews11likes4Comments
March 2024: Exploring open source at Microsoft, and other highlights for developers
Explore some of the open-source projects at Microsoft and resources that will help you start contributing to and managing your own open-source projects. And learn about other news and highlights for developers from around Microsoft.52KViews0likes1CommentBuild next-gen apps with OpenAI and Microsoft Power Platform
Let's discuss how developers can leverage OpenAI's APIs to build next-gen application using Microsoft Power Apps. We will use DALL·E 2 (a new AI system model) to create realistic images and art from a description in natural language.32KViews8likes5CommentsImportant Changes to App Service Managed Certificates: Is Your Certificate Affected?
Overview As part of an upcoming industry-wide change, DigiCert, the Certificate Authority (CA) for Azure App Service Managed Certificates (ASMC), is required to migrate to a new validation platform to meet multi-perspective issuance corroboration (MPIC) requirements. While most certificates will not be impacted by this change, certain site configurations and setups may prevent certificate issuance or renewal starting July 28, 2025. Update December 8, 2025 We’ve published an update in November about how App Service Managed Certificates can now be supported on sites that block public access. This reverses the limitation introduced in July 2025, as mentioned in this blog. Note: This blog post reflects a point-in-time update and will not be revised. For the latest and most accurate details on App Service Managed Certificates, please refer to official documentation or subsequent updates. Learn more about the November 2025 update here: Follow-Up to ‘Important Changes to App Service Managed Certificates’: November 2025 Update. August 5, 2025 We’ve published a Microsoft Learn documentation titled App Service Managed Certificate (ASMC) changes – July 28, 2025 that contains more in-depth mitigation guidance and a growing FAQ section to support the changes outlined in this blog post. While the blog currently contains the most complete overview, the documentation will soon be updated to reflect all blog content. Going forward, any new information or clarifications will be added to the documentation page, so we recommend bookmarking it for the latest guidance. What Will the Change Look Like? For most customers: No disruption. Certificate issuance and renewals will continue as expected for eligible site configurations. For impacted scenarios: Certificate requests will fail (no certificate issued) starting July 28, 2025, if your site configuration is not supported. Existing certificates will remain valid until their expiration (up to six months after last renewal). Impacted Scenarios You will be affected by this change if any of the following apply to your site configurations: Your site is not publicly accessible: Public accessibility to your app is required. If your app is only accessible privately (e.g., requiring a client certificate for access, disabling public network access, using private endpoints or IP restrictions), you will not be able to create or renew a managed certificate. Other site configurations or setup methods not explicitly listed here that restrict public access, such as firewalls, authentication gateways, or any custom access policies, can also impact eligibility for managed certificate issuance or renewal. Action: Ensure your app is accessible from the public internet. However, if you need to limit access to your app, then you must acquire your own SSL certificate and add it to your site. Your site uses Azure Traffic Manager "nested" or "external" endpoints: Only “Azure Endpoints” on Traffic Manager will be supported for certificate creation and renewal. “Nested endpoints” and “External endpoints” will not be supported. Action: Transition to using "Azure Endpoints". However, if you cannot, then you must obtain a different SSL certificate for your domain and add it to your site. Your site relies on *.trafficmanager.net domain: Certificates for *.trafficmanager.net domains will not be supported for creation or renewal. Action: Add a custom domain to your app and point the custom domain to your *.trafficmanager.net domain. After that, secure the custom domain with a new SSL certificate. If none of the above applies, no further action is required. How to Identify Impacted Resources? To assist with the upcoming changes, you can use Azure Resource Graph (ARG) queries to help identify resources that may be affected under each scenario. Please note that these queries are provided as a starting point and may not capture every configuration. Review your environment for any unique setups or custom configurations. Scenario 1: Sites Not Publicly Accessible This ARG query retrieves a list of sites that either have the public network access property disabled or are configured to use client certificates. It then filters for sites that are using App Service Managed Certificates (ASMC) for their custom hostname SSL bindings. These certificates are the ones that could be affected by the upcoming changes. However, please note that this query does not provide complete coverage, as there may be additional configurations impacting public access to your app that are not included here. Ultimately, this query serves as a helpful guide for users, but a thorough review of your environment is recommended. You can copy this query, paste it into Azure Resource Graph Explorer, and then click "Run query" to view the results for your environment. // ARG Query: Identify App Service sites that commonly restrict public access and use ASMC for custom hostname SSL bindings resources | where type == "microsoft.web/sites" // Extract relevant properties for public access and client certificate settings | extend publicNetworkAccess = tolower(tostring(properties.publicNetworkAccess)), clientCertEnabled = tolower(tostring(properties.clientCertEnabled)) // Filter for sites that either have public network access disabled // or have client certificates enabled (both can restrict public access) | where publicNetworkAccess == "disabled" or clientCertEnabled != "false" // Expand the list of SSL bindings for each site | mv-expand hostNameSslState = properties.hostNameSslStates | extend hostName = tostring(hostNameSslState.name), thumbprint = tostring(hostNameSslState.thumbprint) // Only consider custom domains (exclude default *.azurewebsites.net) and sites with an SSL certificate bound | where tolower(hostName) !endswith "azurewebsites.net" and isnotempty(thumbprint) // Select key site properties for output | project siteName = name, siteId = id, siteResourceGroup = resourceGroup, thumbprint, publicNetworkAccess, clientCertEnabled // Join with certificates to find only those using App Service Managed Certificates (ASMC) // ASMCs are identified by the presence of the "canonicalName" property | join kind=inner ( resources | where type == "microsoft.web/certificates" | extend certThumbprint = tostring(properties.thumbprint), canonicalName = tostring(properties.canonicalName) // Only ASMC uses the "canonicalName" property | where isnotempty(canonicalName) | project certName = name, certId = id, certResourceGroup = tostring(properties.resourceGroup), certExpiration = properties.expirationDate, certThumbprint, canonicalName ) on $left.thumbprint == $right.certThumbprint // Final output: sites with restricted public access and using ASMC for custom hostname SSL bindings | project siteName, siteId, siteResourceGroup, publicNetworkAccess, clientCertEnabled, thumbprint, certName, certId, certResourceGroup, certExpiration, canonicalName Scenario 2: Traffic Manager Endpoint Types For this scenario, please manually review your Traffic Manager profile configurations to ensure only “Azure Endpoints” are in use. We recommend inspecting your Traffic Manager profiles directly in the Azure portal or using relevant APIs to confirm your setup and ensure compliance with the new requirements. Scenario 3: Certificates Issued to *.trafficmanager.net Domains This ARG query helps you identify App Service Managed Certificates (ASMC) that were issued to *.trafficmanager.net domains. In addition, it also checks whether any web apps are currently using those certificates for custom domain SSL bindings. You can copy this query, paste it into Azure Resource Graph Explorer, and then click "Run query" to view the results for your environment. // ARG Query: Identify App Service Managed Certificates (ASMC) issued to *.trafficmanager.net domains // Also checks if any web apps are currently using those certificates for custom domain SSL bindings resources | where type == "microsoft.web/certificates" // Extract the certificate thumbprint and canonicalName (ASMCs have a canonicalName property) | extend certThumbprint = tostring(properties.thumbprint), canonicalName = tostring(properties.canonicalName) // Only ASMC uses the "canonicalName" property // Filter for certificates issued to *.trafficmanager.net domains | where canonicalName endswith "trafficmanager.net" // Select key certificate properties for output | project certName = name, certId = id, certResourceGroup = tostring(properties.resourceGroup), certExpiration = properties.expirationDate, certThumbprint, canonicalName // Join with web apps to see if any are using these certificates for SSL bindings | join kind=leftouter ( resources | where type == "microsoft.web/sites" // Expand the list of SSL bindings for each site | mv-expand hostNameSslState = properties.hostNameSslStates | extend hostName = tostring(hostNameSslState.name), thumbprint = tostring(hostNameSslState.thumbprint) // Only consider bindings for *.trafficmanager.net custom domains with a certificate bound | where tolower(hostName) endswith "trafficmanager.net" and isnotempty(thumbprint) // Select key site properties for output | project siteName = name, siteId = id, siteResourceGroup = resourceGroup, thumbprint ) on $left.certThumbprint == $right.thumbprint // Final output: ASMCs for *.trafficmanager.net domains and any web apps using them | project certName, certId, certResourceGroup, certExpiration, canonicalName, siteName, siteId, siteResourceGroup Ongoing Updates We will continue to update this post with any new queries or important changes as they become available. Be sure to check back for the latest information. Note on Comments We hope this information helps you navigate the upcoming changes. To keep this post clear and focused, comments are closed. If you have questions, need help, or want to share tips or alternative detection methods, please visit our official support channels or the Microsoft Q&A, where our team and the community can assist you.26KViews1like1CommentFollow-Up to ‘Important Changes to App Service Managed Certificates’: November 2025 Update
This post provides an update to the Tech Community article ‘Important Changes to App Service Managed Certificates: Is Your Certificate Affected?’ and covers the latest changes introduced since July 2025. With the November 2025 update, ASMC now remains supported even if the site is not publicly accessible, provided all other requirements are met. Details on requirements, exceptions, and validation steps are included below. Background Context to July 2025 Changes As of July 2025, all ASMC certificate issuance and renewals use HTTP token validation. Previously, public access was required because DigiCert needed to access the endpoint https://<hostname>/.well-known/pki-validation/fileauth.txt to verify the token before issuing the certificate. App Service automatically places this token during certificate creation and renewal. If DigiCert cannot access this endpoint, domain ownership validation fails, and the certificate cannot be issued. November 2025 Update Starting November 2025, App Service now allows DigiCert's requests to the https://<hostname>/.well-known/pki-validation/fileauth.txt endpoint, even if the site blocks public access. If there’s a request to create an App Service Managed Certificate (ASMC), App Service places the domain validation token at the validation endpoint. When DigiCert tries to reach the validation endpoint, App Service front ends present the token, and the request terminates at the front end layer. DigiCert's request does not reach the workers running the application. This behavior is now the default for ASMC issuance for initial certificate creation and renewals. Customers do not need to specifically allow DigiCert's IP addresses. Exceptions and Unsupported Scenarios This update addresses most scenarios that restrict public access, including App Service Authentication, disabling public access, IP restrictions, private endpoints, and client certificates. However, a public DNS record is still required. For example, sites using a private endpoint with a custom domain on a private DNS cannot validate domain ownership and obtain a certificate. Even with all validations now relying on HTTP token validation and DigiCert requests being allowed through, certain configurations are still not supported for ASMC: Sites configured as "Nested" or "External" endpoints behind Traffic Manager. Only "Azure" endpoints are supported. Certificates requested for domains ending in *.trafficmanager.net are not supported. Testing Customers can easily test whether their site’s configuration or set-up supports ASMC by attempting to create one for their site. If the initial request succeeds, renewals should also work, provided all requirements are met and the site is not listed in an unsupported scenario.24KViews2likes0Comments
