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55 TopicsIndustry-Wide Certificate Changes Impacting Azure App Service Certificates
Executive Summary In early 2026, industry-wide changes mandated by browser applications and the CA/B Forum will affect both how TLS certificates are issued as well as their validity period. The CA/B Forum is a vendor body that establishes standards for securing websites and online communications through SSL/TLS certificates. Azure App Service is aligning with these standards for both App Service Managed Certificates (ASMC, free, DigiCert-issued) and App Service Certificates (ASC, paid, GoDaddy-issued). Most customers will experience no disruption. Action is required only if you pin certificates or use them for client authentication (mTLS). Update: February 17, 2026 We’ve published new Microsoft Learn documentation, Industry-wide certificate changes impacting Azure App Service , which provides more detailed guidance on these compliance-driven changes. The documentation also includes additional information not previously covered in this blog, such as updates to domain validation reuse, along with an expanding FAQ section. The Microsoft Learn documentation now represents the most complete and up-to-date overview of these changes. Going forward, any new details or clarifications will be published there, and we recommend bookmarking the documentation for the latest guidance. Who Should Read This? App Service administrators Security and compliance teams Anyone responsible for certificate management or application security Quick Reference: What’s Changing & What To Do Topic ASMC (Managed, free) ASC (GoDaddy, paid) Required Action New Cert Chain New chain (no action unless pinned) New chain (no action unless pinned) Remove certificate pinning Client Auth EKU Not supported (no action unless cert is used for mTLS) Not supported (no action unless cert is used for mTLS) Transition from mTLS Validity No change (already compliant) Two overlapping certs issued for the full year None (automated) If you do not pin certificates or use them for mTLS, no action is required. Timeline of Key Dates Date Change Action Required Mid-Jan 2026 and after ASMC migrates to new chain ASMC stops supporting client auth EKU Remove certificate pinning if used Transition to alternative authentication if the certificate is used for mTLS Mar 2026 and after ASC validity shortened ASC migrates to new chain ASC stops supporting client auth EKU Remove certificate pinning if used Transition to alternative authentication if the certificate is used for mTLS Actions Checklist For All Users Review your use of App Service certificates. If you do not pin these certificates and do not use them for mTLS, no action is required. If You Pin Certificates (ASMC or ASC) Remove all certificate or chain pinning before their respective key change dates to avoid service disruption. See Best Practices: Certificate Pinning. If You Use Certificates for Client Authentication (mTLS) Switch to an alternative authentication method before their respective key change dates to avoid service disruption, as client authentication EKU will no longer be supported for these certificates. See Sunsetting the client authentication EKU from DigiCert public TLS certificates. See Set Up TLS Mutual Authentication - Azure App Service Details & Rationale Why Are These Changes Happening? These updates are required by major browser programs (e.g., Chrome) and apply to all public CAs. They are designed to enhance security and compliance across the industry. Azure App Service is automating updates to minimize customer impact. What’s Changing? New Certificate Chain Certificates will be issued from a new chain to maintain browser trust. Impact: Remove any certificate pinning to avoid disruption. Removal of Client Authentication EKU Newly issued certificates will not support client authentication EKU. This change aligns with Google Chrome’s root program requirements to enhance security. Impact: If you use these certificates for mTLS, transition to an alternate authentication method. Shortening of Certificate Validity Certificate validity is now limited to a maximum of 200 days. Impact: ASMC is already compliant; ASC will automatically issue two overlapping certificates to cover one year. No billing impact. Frequently Asked Questions (FAQs) Will I lose coverage due to shorter validity? No. For App Service Certificate, App Service will issue two certificates to span the full year you purchased. Is this unique to DigiCert and GoDaddy? No. This is an industry-wide change. Do these changes impact certificates from other CAs? Yes. These changes are an industry-wide change. We recommend you reach out to your certificates’ CA for more information. Do I need to act today? If you do not pin or use these certs for mTLS, no action is required. Glossary ASMC: App Service Managed Certificate (free, DigiCert-issued) ASC: App Service Certificate (paid, GoDaddy-issued) EKU: Extended Key Usage mTLS: Mutual TLS (client certificate authentication) CA/B Forum: Certification Authority/Browser Forum Additional Resources Changes to the Managed TLS Feature Set Up TLS Mutual Authentication Azure App Service Best Practices – Certificate pinning DigiCert Root and Intermediate CA Certificate Updates 2023 Sunsetting the client authentication EKU from DigiCert public TLS certificates Feedback & Support If you have questions or need help, please visit our official support channels or the Microsoft Q&A, where our team and the community can assist you.2.5KViews1like0CommentsBeyond the Desktop: The Future of Development with Microsoft Dev Box and GitHub Codespaces
The modern developer platform has already moved past the desktop. We’re no longer defined by what’s installed on our laptops, instead we look at what tooling we can use to move from idea to production. An organisations developer platform strategy is no longer a nice to have, it sets the ceiling for what’s possible, an organisation can’t iterate it's way to developer nirvana if the foundation itself is brittle. A great developer platform shrinks TTFC (time to first commit), accelerates release velocity, and maybe most importantly, helps alleviate everyday frictions that lead to developer burnout. Very few platforms deliver everything an organization needs from a developer platform in one product. Modern development spans multiple dimensions, local tooling, cloud infrastructure, compliance, security, cross-platform builds, collaboration, and rapid onboarding. The options organizations face are then to either compromise on one or more of these areas or force developers into rigid environments that slow productivity and innovation. This is where Microsoft Dev Box and GitHub Codespaces come into play. On their own, each addresses critical parts of the modern developer platform: Microsoft Dev Box provides a full, managed cloud workstation. Dev Box gives developers a consistent, high-performance environment while letting central IT apply strict governance and control. Internally at Microsoft, we estimate that usage of Dev Box by our development teams delivers savings of 156 hours per year per developer purely on local environment setup and upkeep. We have also seen significant gains in other key SPACE metrics reducing context-switching friction and improving build/test cycles. Although the benefits of Dev Box are clear in the results demonstrated by our customers it is not without its challenges. The biggest challenge often faced by Dev Box customers is its lack of native Linux support. At the time of writing and for the foreseeable future Dev Box does not support native Linux developer workstations. While WSL2 provides partial parity, I know from my own engineering projects it still does not deliver the full experience. This is where GitHub Codespaces comes into this story. GitHub Codespaces delivers instant, Linux-native environments spun up directly from your repository. It’s lightweight, reproducible, and ephemeral ideal for rapid iteration, PR testing, and cross-platform development where you need Linux parity or containerized workflows. Unlike Dev Box, Codespaces can run fully in Linux, giving developers access to native tools, scripts, and runtimes without workarounds. It also removes much of the friction around onboarding: a new developer can open a repository and be coding in minutes, with the exact environment defined by the project’s devcontainer.json. That said, Codespaces isn’t a complete replacement for a full workstation. While it’s perfect for isolated project work or ephemeral testing, it doesn’t provide the persistent, policy-controlled environment that enterprise teams often require for heavier workloads or complex toolchains. Used together, they fill the gaps that neither can cover alone: Dev Box gives the enterprise-grade foundation, while Codespaces provides the agile, cross-platform sandbox. For organizations, this pairing sets a higher ceiling for developer productivity, delivering a truly hybrid, agile and well governed developer platform. Better Together: Dev Box and GitHub Codespaces in action Together, Microsoft Dev Box and GitHub Codespaces deliver a hybrid developer platform that combines consistency, speed, and flexibility. Teams can spin up full, policy-compliant Dev Box workstations preloaded with enterprise tooling, IDEs, and local testing infrastructure, while Codespaces provides ephemeral, Linux-native environments tailored to each project. One of my favourite use cases is having local testing setups like a Docker Swarm cluster, ready to go in either Dev Box or Codespaces. New developers can jump in and start running services or testing microservices immediately, without spending hours on environment setup. Anecdotally, my time to first commit and time to delivering “impact” has been significantly faster on projects where one or both technologies provide local development services out of the box. Switching between Dev Boxes and Codespaces is seamless every environment keeps its own libraries, extensions, and settings intact, so developers can jump between projects without reconfiguring or breaking dependencies. The result is a turnkey, ready-to-code experience that maximizes productivity, reduces friction, and lets teams focus entirely on building, testing, and shipping software. To showcase this value, I thought I would walk through an example scenario. In this scenario I want to simulate a typical modern developer workflow. Let's look at a day in the life of a developer on this hybrid platform building an IOT project using Python and React. Spin up a ready-to-go workstation (Dev Box) for Windows development and heavy builds. Launch a Linux-native Codespace for cross-platform services, ephemeral testing, and PR work. Run "local" testing like a Docker Swarm cluster, database, and message queue ready to go out-of-the-box. Switch seamlessly between environments without losing project-specific configurations, libraries, or extensions. 9:00 AM – Morning Kickoff on Dev Box I start my day on my Microsoft Dev Box, which gives me a fully-configured Windows environment with VS Code, design tools, and Azure integrations. I select my teams project, and the environment is pre-configured for me through the Dev Box catalogue. Fortunately for me, its already provisioned. I could always self service another one using the "New Dev Box" button if I wanted too. I'll connect through the browser but I could use the desktop app too if I wanted to. My Tasks are: Prototype a new dashboard widget for monitoring IoT device temperature. Use GUI-based tools to tweak the UI and preview changes live. Review my Visio Architecture. Join my morning stand up. Write documentation notes and plan API interactions for the backend. In a flash, I have access to my modern work tooling like Teams, I have this projects files already preloaded and all my peripherals are working without additional setup. Only down side was that I did seem to be the only person on my stand up this morning? Why Dev Box first: GUI-heavy tasks are fast and responsive. Dev Box’s environment allows me to use a full desktop. Great for early-stage design, planning, and visual work. Enterprise Apps are ready for me to use out of the box (P.S. It also supports my multi-monitor setup). I use my Dev Box to make a very complicated change to my IoT dashboard. Changing the title from "IoT Dashboard" to "Owain's IoT Dashboard". I preview this change in a browser live. (Time for a coffee after this hardwork). The rest of the dashboard isnt loading as my backend isnt running... yet. 10:30 AM – Switching to Linux Codespaces Once the UI is ready, I push the code to GitHub and spin up a Linux-native GitHub Codespace for backend development. Tasks: Implement FastAPI endpoints to support the new IoT feature. Run the service on my Codespace and debug any errors. Why Codespaces now: Linux-native tools ensure compatibility with the production server. Docker and containerized testing run natively, avoiding WSL translation overhead. The environment is fully reproducible across any device I log in from. 12:30 PM – Midday Testing & Sync I toggle between Dev Box and Codespaces to test and validate the integration. I do this in my Dev Box Edge browser viewing my codespace (I use my Codespace in a browser through this demo to highlight the difference in environments. In reality I would leverage the VSCode "Remote Explorer" extension and its GitHub Codespace integration to use my Codespace from within my own desktop VSCode but that is personal preference) and I use the same browser to view my frontend preview. I update the environment variable for my frontend that is running locally in my Dev Box and point it at the port running my API locally on my Codespace. In this case it was a web socket connection and HTTPS calls to port 8000. I can make this public by changing the port visibility in my Codespace. https://fluffy-invention-5x5wp656g4xcp6x9-8000.app.github.dev/api/devices wss://fluffy-invention-5x5wp656g4xcp6x9-8000.app.github.dev/ws This allows me to: Preview the frontend widget on Dev Box, connecting to the backend running in Codespaces. Make small frontend adjustments in Dev Box while monitoring backend logs in Codespaces. Commit changes to GitHub, keeping both environments in sync and leveraging my CI/CD for deployment to the next environment. We can see the Dev Box running local frontend and the Codespace running the API connected to each other, making requests and displaying the data in the frontend! Hybrid advantage: Dev Box handles GUI previews comfortably and allows me to live test frontend changes. Codespaces handles production-aligned backend testing and Linux-native tools. Dev Box allows me to view all of my files in one screen with potentially multiple Codespaces running in browser of VS Code Desktop. Due to all of those platform efficiencies I have completed my days goals within an hour or two and now I can spend the rest of my day learning about how to enable my developers to inner source using GitHub CoPilot and MCP (Shameless plug). The bottom line There are some additional considerations when architecting a developer platform for an enterprise such as private networking and security not covered in this post but these are implementation details to deliver the described developer experience. Architecting such a platform is a valuable investment to deliver the developer platform foundations we discussed at the top of the article. While in this demo I have quickly built I was working in a mono repository in real engineering teams it is likely (I hope) that an application is built of many different repositories. The great thing about Dev Box and Codespaces is that this wouldn’t slow down the rapid development I can achieve when using both. My Dev Box would be specific for the project or development team, pre loaded with all the tools I need and potentially some repos too! When I need too I can quickly switch over to Codespaces and work in a clean isolated environment and push my changes. In both cases any changes I want to deliver locally are pushed into GitHub (Or ADO), merged and my CI/CD ensures that my next step, potentially a staging environment or who knows perhaps *Whispering* straight into production is taken care of. Once I’m finished I delete my Codespace and potentially my Dev Box if I am done with the project, knowing I can self service either one of these anytime and be up and running again! Now is there overlap in terms of what can be developed in a Codespace vs what can be developed in Azure Dev Box? Of course, but as organisations prioritise developer experience to ensure release velocity while maintaining organisational standards and governance then providing developers a windows native and Linux native service both of which are primarily charged on the consumption of the compute* is a no brainer. There are also gaps that neither fill at the moment for example Microsoft Dev Box only provides windows compute while GitHub Codespaces only supports VS Code as your chosen IDE. It's not a question of which service do I choose for my developers, these two services are better together! *Changes have been announced to Dev Box pricing. A W365 license is already required today and dev boxes will continue to be managed through Azure. For more information please see: Microsoft Dev Box capabilities are coming to Windows 365 - Microsoft Dev Box | Microsoft Learn1.2KViews2likes0CommentsModernizing Spring Framework Applications with GitHub Copilot App Modernization
Upgrading Spring Framework applications from version 5 to the latest 6.x line (including 6.2+) enables improved performance, enhanced security, alignment with modern Java releases, and full Jakarta namespace compatibility. The transition often introduces breaking API changes, updated module requirements, and dependency shifts. GitHub Copilot app modernization streamlines this upgrade by analyzing your project, generating targeted changes, and guiding you through the migration. Supported Upgrade Path GitHub Copilot app modernization supports: Upgrading Spring Framework to 6.x, including 6.2+ Migrating from javax to jakarta Aligning transitive dependencies and version constraints Updating build plugins and configurations Identifying deprecated or removed APIs Validating dependency updates and surfacing CVE issues These capabilities align with the Microsoft Learn quickstart for upgrading Java projects with GitHub Copilot app modernization. Project Setup Open your Spring Framework project in Visual Studio Code or IntelliJ IDEA with GitHub Copilot app modernization enabled. The tool works with Maven or Gradle projects and evaluates your existing Spring Framework, Java version, imports, and build configurations. Project Analysis When you trigger the upgrade, GitHub Copilot app modernization: Detects the current Spring Framework version Flags javax imports requiring Jakarta migration Identifies incompatible modules, libraries, and plugins Validates JDK compatibility requirements for Spring Framework 6.x Reviews transitive dependencies impacted by the update This analysis provides the foundation for the upgrade plan generated next. Upgrade Plan Generation GitHub Copilot app modernization produces a structured plan including: Updated Spring Framework version (6.x / 6.2+) Replacements for deprecated or removed APIs jakarta namespace updates Updated build plugins and version constraints JDK configuration adjustments You can review the plan, modify version targets, and confirm actions before the tool applies them. Automated Transformations After approval, GitHub Copilot app modernization applies automated changes such as: Updating Spring Framework module coordinates Rewriting imports from javax.* to jakarta.* Updating libraries required for Spring Framework 6.x Adjusting plugin versions and build logic Recommending fixes for API changes These transformations rely on OpenRewrite‑based rules to modernize your codebase efficiently. Build Fix Iteration Once changes are applied, the tool compiles your project and automatically responds to failures: Captures compilation errors Suggests targeted fixes Rebuilds iteratively This loop continues until the project compiles with Spring Framework 6.x in place. Security & Behavior Checks GitHub Copilot app modernization performs validation steps after the upgrade: Checks for CVEs in updated dependencies Identifies potential behavior changes introduced during the transition Offers optional fixes to address issues This adds confidence before final verification. Expected Output After a Spring Framework 5 → 6.x upgrade, you can expect: Updated module coordinates for Spring Framework 6.x / 6.2 jakarta‑aligned imports across the codebase Updated dependency versions aligned with the new Spring ecosystem Updated plugins and build tool configurations Modernized test stack (JUnit 5) A summary file detailing versions updated, code edits applied, dependencies changed, and items requiring manual review Developer Responsibilities GitHub Copilot app modernization accelerates framework upgrade mechanics, but developers remain responsible for: Running full test suites Reviewing custom components, filters, and validation logic Revisiting security configurations and reactive vs. servlet designs Checking integration points and application semantics post‑migration The tool handles the mechanical modernization work so you can focus on correctness, runtime behavior, and quality assurance. Learn More For prerequisites, setup steps, and the complete Java upgrade workflow, refer to the Microsoft Learn guide: Upgrade a Java Project with Github Copilot App Modernization Install GitHub Copilot app modernization for VS Code and IntelliJ IDEA183Views0likes0CommentsUpgrade your Java JDK (8, 11, 17, 21, or 25) with GitHub Copilot App Modernization
Developers modernizing Java applications often need to upgrade the Java Development Kit (JDK), update frameworks, align dependencies, or migrate older stacks such as Java EE. GitHub Copilot app modernization dramatically speeds up this process by analyzing your project, identifying upgrade blockers, and generating targeted changes. This post highlights supported upgrade paths and what you can expect when using GitHub Copilot app modernization—optimized for search discoverability rather than deep tutorial content. For complete, authoritative guidance, refer to the official Microsoft Learn quickstart. Supported Upgrade Scenarios GitHub Copilot app modernization supports upgrading: Java Development Kit (JDK) to versions 8, 11, 17, 21, or 25 Spring Boot up to 3.5 Spring Framework up to 6.2+ Java EE → Jakarta EE (up to Jakarta EE 10) JUnit Third‑party dependencies to specified versions Ant → Maven build migrations For the full capabilities list, see the Microsoft Learn quickstart. Prerequisites (VS Code or IntelliJ) To use GitHub Copilot app modernization, you’ll need: GitHub account + GitHub Copilot Free Tier, Pro, Pro+, Business, or Enterprise Visual Studio Code Version 1.101+ GitHub Copilot extension GitHub Copilot app modernization extension Restart after installation IntelliJ IDEA Version 2023.3+ GitHub Copilot plugin 1.5.59+ Restart after installation Recommended: Auto‑approve MCP Tool Annotations under Tools > GitHub Project Requirements Java project using Maven or Gradle Git‑managed Maven access to public Maven Central (if Maven) Gradle wrapper version 5+ Kotlin DSL supported VS Code setting: “Tools enabled” set to true if controlled by your org Selecting a Java Project to Upgrade Open any Java project in: Visual Studio Code IntelliJ IDEA Optional sample projects: Maven: uportal‑messaging Gradle: docraptor‑java Once open, launch GitHub Copilot app modernization using Agent Mode. Running an Upgrade (Example: Java 8 → Java 21) Open GitHub Copilot Chat → Switch to Agent Mode → Run a prompt such as: Upgrade this project to Java 21 You’ll receive: Upgrade Plan JDK version updates Build file changes (Maven/Gradle) Dependency version adjustments Framework upgrade paths, if relevant Automated Transformations GitHub Copilot app modernization applies changes using OpenRewrite‑based transformations. Dynamic Build / Fix Loop The agent iterates: Build Detect failure Fix Retry Until the project builds successfully. Security & Behavior Checks Detects CVEs in upgraded dependencies Flags potential behavior changes Offers optional fixes Final Upgrade Summary Generated as a markdown file containing: Updated JDK level Dependencies changed Code edits made Any remaining CVEs or warnings What You Can Expect in a JDK Upgrade Typical outcomes from upgrading Java 8 → Java 21: Updated build configuration (maven.compiler.release → 21) Removal or replacement of deprecated JDK APIs Updated library versions for Java 21 compatibility Surface warnings for manual review Successfully building project with modern JDK settings GitHub Copilot app modernization accelerates these updates while still leaving space for developer review of runtime or architectural changes. Learn More For the complete, authoritative upgrade workflow—covering setup, capabilities, and the full end‑to‑end process—visit: ➡ Quickstart: Upgrade a Java project with GitHub Copilot app modernization (Microsoft Learn) Install GitHub Copilot app modernization for VS Code and IntelliJ IDEA510Views0likes0CommentsMigrating Application Credentials to Azure Key Vault with GitHub Copilot App Modernization
Storing secrets directly in applications or configuration files increases operational risk. Migrating to Azure Key Vault centralizes secret management, supports rotation, and removes embedded credentials from application code. GitHub Copilot app modernization accelerates this process by identifying credential usage areas and generating changes for Key Vault integration. What This Migration Covers GitHub Copilot app modernization helps with: Detecting secrets hard‑coded in source files, config files, or environment variables. Recommending retrieval patterns using Azure Key Vault SDKs. Updating application code to load secrets from Key Vault. Preparing configuration updates to remove stored credentials. Surfacing dependency, version, and API adjustments required for Key Vault usage. Project Analysis Once the project is opened in Visual Studio Code or IntelliJ IDEA, GitHub Copilot app modernization analyzes: Hard‑coded credentials: passwords, tokens, client secrets, API keys. Legacy configuration patterns using .properties, .yaml, or environment variables. Azure SDK usage and required upgrades for Key Vault integration. Areas requiring secure retrieval or replacement with a managed identity. Migration Plan Generation The tool creates a step‑by‑step migration plan including: Introducing Key Vault client libraries. Mapping existing credential variables to Key Vault secrets. Updating configuration loading logic to retrieve secrets at runtime. Integrating Managed Identity authentication if applicable. Removing unused credential fields from code and configuration. Automated Transformations GitHub Copilot app modernization applies targeted changes: Rewrites code retrieving credentials from files or constants. Generates Key Vault retrieval patterns using SecretClient. Updates build dependencies to current Azure SDK versions. Removes unused configuration entries and environment variables. Build & Fix Iteration The project is rebuilt and validated: Fixes constructor changes related to updated clients. Resolves missing dependency versions. Corrects updated method signatures for Key Vault API calls. Rebuilds until no actionable errors remain. Security & Behavior Checks The tool surfaces: CVEs introduced by new or updated libraries. Behavior changes tied to lazy loading of secrets at runtime. Optional fixes or alternative patterns if Key Vault integration affects existing workflows. Expected Output After modernization: Credentials removed from source and config files. Application retrieves secrets from Azure Key Vault. Updated Azure SDK versions aligned with Key Vault. A summary file detailing code changes, dependency updates, and review items. Developer Responsibilities Developers should: Provision Key Vault resources and assign required access policies. Validate permissions through Managed Identity or service principals. Test application startup, error handling, and rotation scenarios. Review semantic impacts on components relying on early secret loading. Refer to the Microsoft Learn guide on upgrading Java projects with GitHub Copilot app modernization for foundational workflow details. Learn more Predefined tasks for GitHub Copilot app modernization Apply a predefined task Install GitHub Copilot app modernization for VS Code and IntelliJ IDEA312Views0likes0CommentsModernizing Applications by Migrating Code to Use Managed Identity with Copilot App Modernization
Migrating application code to use Managed Identity removes hard‑coded secrets, reduces operational risk, and aligns with modern cloud security practices. Applications authenticate directly with Azure services without storing credentials. GitHub Copilot app modernization streamlines this transition by identifying credential usage patterns, updating code, and aligning dependencies for Managed Identity flows. Supported Migration Steps GitHub Copilot app modernization helps accelerate: Replacing credential‑based authentication with Managed Identity authentication. Updating SDK usage to token‑based flows. Refactoring helper classes that build credential objects. Surfacing libraries or APIs that require alternative authentication approaches. Preparing build configuration changes needed for managed identity integration. Migration Analysis Open the project in Visual Studio Code or IntelliJ IDEA. GitHub Copilot app modernization analyzes: Locations where secrets, usernames, passwords, or connection strings are referenced. Service clients using credential constructors or static credential factories. Environment‑variable‑based authentication workarounds. Dependencies and SDK versions required for Managed Identity authentication. The analysis outlines upgrade blockers and the required changes for cloud‑native authentication. Migration Plan Generation GitHub Copilot app modernization produces a migration plan containing: Replacement of hard‑coded credentials with Managed Identity authentication patterns. Version updates for Azure libraries aligning with Managed Identity support. Adjustments to application configuration to remove unnecessary secrets. Developers can review and adjust before applying. Automated Transformations GitHub Copilot app modernization applies changes: Rewrites code that initializes clients using username/password or connection strings. Introduces Managed Identity‑friendly constructors and token credential patterns. Updates imports, method signatures, and helper utilities. Cleans up configuration files referencing outdated credential flows. Build & Fix Iteration The tool rebuilds the project, identifies issues, and applies targeted fixes: Compilation errors from removed credential classes. Incorrect parameter types or constructors. Dependencies requiring updates for Managed Identity compatibility. Security & Behavior Checks GitHub Copilot app modernization validates: CVEs introduced through dependency updates. Behavior changes caused by new authentication flows. Optional fixes for dependency vulnerabilities. Expected Output A migrated codebase using Managed Identity: Updated authentication logic. Removed credential references. Updated SDKs and dependencies. A summary file listing code edits, dependency changes, and items requiring manual review. Developer Responsibilities Developers should: Validate identity access on Azure resources. Reconfigure role assignments for system‑assigned or user‑assigned managed identities. Test functional behavior across environments. Review integration points dependent on identity scopes and permissions. Learn full upgrade workflows in the Microsoft Learn guide for upgrading Java projects with GitHub Copilot app modernization. Learn more Predefined tasks for GitHub Copilot app modernization Apply a predefined task Install GitHub Copilot app modernization for VS Code and IntelliJ IDEA256Views0likes0CommentsSecure Unique Default Hostnames Now GA for Functions and Logic Apps
We are pleased to announce that Secure Unique Default Hostnames are now generally available (GA) for Azure Functions and Logic Apps (Standard). This expands the security model previously available for Web Apps to the entire App Service ecosystem and provides customers with stronger, more secure, and standardized hostname behavior across all workloads. Why This Feature Matters Historically, App Service resources have used default hostname format such as: <SiteName>.azurewebsites.net While straightforward, this pattern introduced potential security risks, particularly in scenarios where DNS records were left behind after deleting a resource. In those situations, a different user could create a new resource with the same name and unintentionally receive traffic or bindings associated with the old DNS configuration, creating opportunities for issues such as subdomain takeover. Secure Unique Default Hostnames address this by assigning a unique, randomized, region‑scoped hostname to each resource, for example: <SiteName>-<Hash>.<Region>.azurewebsites.net This change ensures that: No other customer can recreate the same default hostname. Apps inherently avoid risks associated with dangling DNS entries. Customers gain a more secure, reliable baseline behavior across App Service. Adopting this model now helps organizations prepare for the long‑term direction of the platform while improving security posture today. What’s New: GA Support for Functions and Logic Apps With this release, both Azure Functions and Logic Apps (Standard) fully support the Secure Unique Default Hostname capability. This brings these services in line with Web Apps and ensures customers across all App Service workloads benefit from the same secure and consistent default hostname model. Azure CLI Support The Azure CLI for Web Apps and Function Apps now includes support for the “--domain-name-scope” parameter. This allows customers to explicitly specify the scope used when generating a unique default hostname during resource creation. Examples: az webapp create --domain-name-scope {NoReuse, ResourceGroupReuse, SubscriptionReuse, TenantReuse} az functionapp create --domain-name-scope {NoReuse, ResourceGroupReuse, SubscriptionReuse, TenantReuse} Including this parameter ensures that deployments consistently use the intended hostname scope and helps teams prepare their automation and provisioning workflows for the secure unique default hostname model. Why Customers Should Adopt This Now While existing resources will continue to function normally, customers are strongly encouraged to adopt Secure Unique Default Hostnames for all new deployments. Early adoption provides several important benefits: A significantly stronger security posture. Protection against dangling DNS and subdomain takeover scenarios. Consistent default hostname behavior as the platform evolves. Alignment with recommended deployment practices and modern DNS hygiene. This feature represents the current best practice for hostname management on App Service and adopting it now helps ensure that new deployments follow the most secure and consistent model available. Recommended Next Steps Enable Secure Unique Default Hostnames for all new Web Apps, Function Apps, and Logic Apps. Update automation and CLI scripts to include the --domain-name-scope parameter when creating new resources. Begin updating internal documentation and operational processes to reflect the new hostname pattern. Additional Resources For readers who want to explore the technical background and earlier announcements in more detail, the following articles offer deeper coverage of unique default hostnames: Public Preview: Creating Web App with a Unique Default Hostname This article introduces the foundational concepts behind unique default hostnames. It explains why the feature was created, how the hostname format works, and provides examples and guidance for enabling the feature when creating new resources. Secure Unique Default Hostnames: GA on App Service Web Apps and Public Preview on Functions This article provides the initial GA announcement for Web Apps and early preview details for Functions. It covers the security benefits, recommended usage patterns, and guidance on how to handle existing resources that were created without unique default hostnames. Conclusion Secure Unique Default Hostnames now provide a more secure and consistent default hostname model across Web Apps, Function Apps, and Logic Apps. This enhancement reduces DNS‑related risks and strengthens application security, and organizations are encouraged to adopt this feature as the standard for new deployments.620Views0likes0CommentsSearch Less, Build More: Inner Sourcing with GitHub Copilot and ADO MCP Server
Developers burn cycles context‑switching: opening five repos to find a logging example, searching a wiki for a data masking rule, scrolling chat history for the latest pipeline pattern. Organisations that I speak to are often on the path of transformational platform engineering projects but always have the fear or doubt of "what if my engineers don't use these resources". While projects like Backstage still play a pivotal role in inner sourcing and discoverability I also empathise with developers who would argue "How would I even know in the first place, which modules have or haven't been created for reuse". In this blog we explore how we can ensure organisational standards and developer satisfaction without any heavy lifting on either side, no custom model training, no rewriting or relocating of repositories and no stagnant local data. Using GitHub Copilot + Azure DevOps MCP server (with the free `code_search` extension) we turn the IDE into an organizational knowledge interface. Instead of guessing or re‑implementing, engineers can start scaffolding projects or solving issues as they would normally (hopefully using Copilot) and without extra prompting. GitHub Copilot can lean into organisational standards and ensure recommendations are made with code snippets directly generated from existing examples. What Is the Azure DevOps MCP Server + code_search Extension? MCP (Model Context Protocol) is an open standard that lets agents (like GitHub Copilot) pull in structured, on-demand context from external systems. MCP servers contain natural language explanations of the tools that the agent can utilise allowing dynamic decision making of when to implement certain toolsets over others. The Azure DevOps MCP Server is the ADO Product Team's implementation of that standard. It exposes your ADO environment in a way Copilot can consume. Out of the box it gives you access to: Projects – list and navigate across projects in your organization. Repositories – browse repos, branches, and files. Work items – surface user stories, bugs, or acceptance criteria. Wiki's – pull policies, standards, and documentation. This means Copilot can ground its answers in live ADO content, instead of hallucinating or relying only on what’s in the current editor window. The ADO server runs locally from your own machine to ensure that all sensitive project information remains within your secure network boundary. This also means that existing permissions on ADO objects such as Projects or Repositories are respected. Wiki search tooling available out of the box with ADO MCP server is very useful however if I am honest I have seen these wiki's go unused with documentation being stored elsewhere either inside the repository or in a project management tool. This means any tool that needs to implement code requires the ability to accurately search the code stored in the repositories themself. That is where the code_search extension enablement in ADO is so important. Most organisations have this enabled already however it is worth noting that this pre-requisite is the real unlock of cross-repo search. This allows for Copilot to: Query for symbols, snippets, or keywords across all repos. Retrieve usage examples from code, not just docs. Locate standards (like logging wrappers or retry policies) wherever they live. Back every recommendation with specific source lines. In short: MCP connects Copilot to Azure DevOps. code_search makes that connection powerful by turning it into a discovery engine. What is the relevance of Copilot Instructions? One of the less obvious but most powerful features of GitHub Copilot is its ability to follow instructions files. Copilot automatically looks for these files and uses them as a “playbook” for how it should behave. There are different types of instructions you can provide: Organisational instructions – apply across your entire workspace, regardless of which repo you’re in. Repo-specific instructions – scoped to a particular repository, useful when one project has unique standards or patterns. Personal instructions – smaller overrides layered on top of global rules when a local exception applies. (Stored in .github/copilot-instructions.md) In this solution, I’m using a single personal instructions file. It tells Copilot: When to search (e.g., always query repos and wikis before answering a standards question). Where to look (Azure DevOps repos, wikis, and with code_search, the code itself). How to answer (responses must cite the repo/file/line or wiki page; if no source is found, say so). How to resolve conflicts (prefer dated wiki entries over older README fragments). As a small example, a section of a Copilot instruction file could look like this: # GitHub Copilot Instructions for Azure DevOps MCP Integration This project uses Azure DevOps with MCP server integration to provide organizational context awareness. Always check to see if the Azure DevOps MCP server has a tool relevant to the user's request. ## Core Principles ### 1. Azure DevOps Integration - **Always prioritize Azure DevOps MCP tools** when users ask about: - Work items, stories, bugs, tasks - Pull requests and code reviews - Build pipelines and deployments - Repository operations and branch management - Wiki pages and documentation - Test plans and test cases - Project and team information ### 2. Organizational Context Awareness - Before suggesting solutions, **check existing organizational patterns** by: - Searching code across repositories for similar implementations - Referencing established coding standards and frameworks - Looking for existing shared libraries and utilities - Checking architectural decision records (ADRs) in wikis ### 3. Cross-Repository Intelligence - When providing code suggestions: - **Search for existing patterns** in other repositories first - **Reference shared libraries** and common utilities - **Maintain consistency** with organizational standards - **Suggest reusable components** when appropriate ## Tool Usage Guidelines ### Work Items and Project Management When users mention bugs, features, tasks, or project planning: ``` ✅ Use: wit_my_work_items, wit_create_work_item, wit_update_work_item ✅ Use: wit_list_backlogs, wit_get_work_items_for_iteration ✅ Use: work_list_team_iterations, core_list_projects The result... To test this I created 3 ADO Projects each with between 1-2 repositories. The repositories were light with only ReadMe's inside containing descriptions of the "repo" and some code snippets examples for usage. I have then created a brand-new workspace with no context apart from a Copilot instructions document (which could be part of a repo scaffold or organisation wide) which tells Copilot to search code and the wikis across all ADO projects in my demo environment. It returns guidance and standards from all available repo's and starts to use it to formulate its response. In the screenshot I have highlighted some key parts with red boxes. The first being a section of the readme that Copilot has identified in its response, that part also highlighted within CoPilot chat response. I have highlighted the rather generic prompt I used to get this response at the bottom of that window too. Above I have highlighted Copilot using the MCP server tooling searching through projects, repo's and code. Finally the largest box highlights the instructions given to Copilot on how to search and how easily these could be optimised or changed depending on the requirements and organisational coding standards. How did I implement this? Implementation is actually incredibly simple. As mentioned I created multiple projects and repositories within my ADO Organisation in order to test cross-project & cross-repo discovery. I then did the following: Enable code_search - in your Azure DevOps organization (Marketplace → install extension). Login to Azure - Use the AZ CLI to authenticate to Azure with "az login". Create vscode/mcp.json file - Snippet is provided below, the organisation name should be changed to your organisations name. Start and enable your MCP server - In the mcp.json file you should see a "Start" button. Using the snippet below you will be prompted to add your organisation name. Ensure your Copilot agent has access to the server under "tools" too. View this setup guide for full setup instructions (azure-devops-mcp/docs/GETTINGSTARTED.md at main · microsoft/azure-devops-mcp) Create a Copilot Instructions file - with a search-first directive. I have inserted the full version used in this demo at the bottom of the article. Experiment with Prompts – Start generic (“How do we secure APIs?”). Review the output and tools used and then tailor your instructions. Considerations While this is a great approach I do still have some considerations when going to production. Latency - Using MCP tooling on every request will add some latency to developer requests. We can look at optimizing usage through copilot instructions to better identify when Copilot should or shouldn't use the ADO MCP server. Complex Projects and Repositories - While I have demonstrated cross project and cross repository retrieval my demo environment does not truly simulate an enterprise ADO environment. Performance should be tested and closely monitored as organisational complexity increases. Public Preview - The ADO MCP server is moving quickly but is currently still public preview. We have demonstrated in this article how quickly we can make our Azure DevOps content discoverable. While their are considerations moving forward this showcases a direction towards agentic inner sourcing. Feel free to comment below how you think this approach could be extended or augmented for other use cases! Resources MCP Server Config (/.vscode/mcp.json) { "inputs": [ { "id": "ado_org", "type": "promptString", "description": "Azure DevOps organization name (e.g. 'contoso')" } ], "servers": { "ado": { "type": "stdio", "command": "npx", "args": ["-y", "@azure-devops/mcp", "${input:ado_org}"] } } } Copilot Instructions (/.github/copilot-instructions.md) # GitHub Copilot Instructions for Azure DevOps MCP Integration This project uses Azure DevOps with MCP server integration to provide organizational context awareness. Always check to see if the Azure DevOps MCP server has a tool relevant to the user's request. ## Core Principles ### 1. Azure DevOps Integration - **Always prioritize Azure DevOps MCP tools** when users ask about: - Work items, stories, bugs, tasks - Pull requests and code reviews - Build pipelines and deployments - Repository operations and branch management - Wiki pages and documentation - Test plans and test cases - Project and team information ### 2. Organizational Context Awareness - Before suggesting solutions, **check existing organizational patterns** by: - Searching code across repositories for similar implementations - Referencing established coding standards and frameworks - Looking for existing shared libraries and utilities - Checking architectural decision records (ADRs) in wikis ### 3. Cross-Repository Intelligence - When providing code suggestions: - **Search for existing patterns** in other repositories first - **Reference shared libraries** and common utilities - **Maintain consistency** with organizational standards - **Suggest reusable components** when appropriate ## Tool Usage Guidelines ### Work Items and Project Management When users mention bugs, features, tasks, or project planning: ``` ✅ Use: wit_my_work_items, wit_create_work_item, wit_update_work_item ✅ Use: wit_list_backlogs, wit_get_work_items_for_iteration ✅ Use: work_list_team_iterations, core_list_projects ``` ### Code and Repository Operations When users ask about code, branches, or pull requests: ``` ✅ Use: repo_list_repos_by_project, repo_list_pull_requests_by_repo ✅ Use: repo_list_branches_by_repo, repo_search_commits ✅ Use: search_code for finding patterns across repositories ``` ### Documentation and Knowledge Sharing When users need documentation or want to create/update docs: ``` ✅ Use: wiki_list_wikis, wiki_get_page_content, wiki_create_or_update_page ✅ Use: search_wiki for finding existing documentation ``` ### Build and Deployment When users ask about builds, deployments, or CI/CD: ``` ✅ Use: pipelines_get_builds, pipelines_get_build_definitions ✅ Use: pipelines_run_pipeline, pipelines_get_build_status ``` ## Response Patterns ### 1. Discovery First Before providing solutions, always discover organizational context: ``` "Let me first check what patterns exist in your organization..." → Search code, check repositories, review existing work items ``` ### 2. Reference Organizational Standards When suggesting code or approaches: ``` "Based on patterns I found in your [RepositoryName] repository..." "Following your organization's standard approach seen in..." "This aligns with the pattern established in [TeamName]'s implementation..." ``` ### 3. Actionable Integration Always offer to create or update Azure DevOps artifacts: ``` "I can create a work item for this enhancement..." "Should I update the wiki page with this new pattern?" "Let me link this to the current iteration..." ``` ## Specific Scenarios ### New Feature Development 1. **Search existing repositories** for similar features 2. **Check architectural patterns** and shared libraries 3. **Review related work items** and planning documents 4. **Suggest implementation** based on organizational standards 5. **Offer to create work items** and documentation ### Bug Investigation 1. **Search for similar issues** across repositories and work items 2. **Check related builds** and recent changes 3. **Review test results** and failure patterns 4. **Provide solution** based on organizational practices 5. **Offer to create/update** bug work items and documentation ### Code Review and Standards 1. **Compare against organizational patterns** found in other repositories 2. **Reference coding standards** from wiki documentation 3. **Suggest improvements** based on established practices 4. **Check for reusable components** that could be leveraged ### Documentation Requests 1. **Search existing wikis** for related content 2. **Check for ADRs** and technical documentation 3. **Reference patterns** from similar projects 4. **Offer to create/update** wiki pages with findings ## Error Handling If Azure DevOps MCP tools are not available or fail: 1. **Inform the user** about the limitation 2. **Provide alternative approaches** using available information 3. **Suggest manual steps** for Azure DevOps integration 4. **Offer to help** with configuration if needed ## Best Practices ### Always Do: - ✅ Search organizational context before suggesting solutions - ✅ Reference existing patterns and standards - ✅ Offer to create/update Azure DevOps artifacts - ✅ Maintain consistency with organizational practices - ✅ Provide actionable next steps ### Never Do: - ❌ Suggest solutions without checking organizational context - ❌ Ignore existing patterns and implementations - ❌ Provide generic advice when specific organizational context is available - ❌ Forget to offer Azure DevOps integration opportunities --- **Remember: The goal is to provide intelligent, context-aware assistance that leverages the full organizational knowledge base available through Azure DevOps while maintaining development efficiency and consistency.**1.5KViews1like3CommentsImportant 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.25KViews1like1CommentFollow-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.12KViews1like0Comments