If the certificate wasn't issued by a trusted CA (for example, a self-signed certificate was used), users should upload the issuer's certificate to Application Gateway. For File name, name the certificate file. Most of the browsers are thick clients , so it may work in the new browsers but PRODUCTs like Application Gateway will not be able to trust the cert unless the backend sends the complete chain. privacy statement. OpenSSL> s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts I have created an application gateway with 3 backend nodes, when I set the "Http Listener" with all the 3 nodes certificates, the health probe is green. But if the backend health for all the servers in a backend pool is unhealthy or unknown, you might encounter problems when you try to access when the backend server cert hits AppGW after Server Hello , AppGW tries to check who issued the certificate and it finds that it was issued by Intermediate certificate but then it does not have information about Intermediate cert, like who issued the cert and what is the root certificate of that intermediate certificate. Trusted root certificate is required to allow backend instances in application gateway v2 SKU. You should remove the exported trusted root you added in the App Gateway. If you are not familiar with Cloud Shell, it allows you to access bash or powershell from your browser to run commands within your Azure subscription https://docs.microsoft.com/en-us/azure/cloud-shell/overview. You can use any tool to access the backend server, including a browser using developer tools. Ive recently faced with the dreaded 502 Web Server error when dealing with the App Gateway, my Backend Health was screaming unhealthy Backend server certificate is not whitelisted with Application Gateway. An Azure service that provides a platform-managed, scalable, and highly available application delivery controller as a service. Verify that the response body in the Application Gateway custom probe configuration matches what's configured. Configure that certificate on your backend server. of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. For example, you can configure Application Gateway to accept "unauthorized" as a string to match. d. To check the effective routes and rules for a network adapter, you can use the following PowerShell commands: If you don't find any issues with NSG or UDR, check your backend server for application-related issues that are preventing clients from establishing a TCP session on the ports configured. Version Independent ID: <---> Ensure that you create a default website in the IIS with-in the VM without the SNI enabled and you should not see this error. Set the destination port as anything, and verify the connectivity. b. f. Select Save and verify that you can view the backend as Healthy. @krish-gh actually it was actually what have i tried firstly but sitouiotion was same. Sign in to the machine where your application is hosted. Well occasionally send you account related emails. Cause: End-to-end SSL with Application Gateway v2 requires the backend server's certificate to be verified in order to deem the server Healthy. Or, if Pick hostname from backend HTTP settings is selected in the custom probe, SNI will be set from the host name mentioned in the HTTP settings. d. Check your OS firewall settings to make sure that incoming traffic to the port is allowed. @TravisCragg-MSFT: I have same configuration on different places which were built a while ago and those are perfectly working fine. Solution: Depending on the backend server's response code, you can take the following steps. You can choose to use any other tool that is convenient. But when we have multiple chain certificate and if your backend application/server sends only the leaf the certificate , AppGW will not be able to trust the cert up to the top level domain root. Have a question about this project? The issue was on certificate. After the server starts responding #please-close. Your certificate is successfully exported. For more information about how to extract and upload Trusted Root Certificates in Application Gateway, see Export trusted root certificate (for v2 SKU). Already on GitHub? here is what happens in in Multiple chain certificate. The default route is advertised by an ExpressRoute/VPN connection to a virtual network over BGP. You can find this by running openssl from either windows client or Linux client which is present in the same network/subnet of the backend application. Message: The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. You signed in with another tab or window. In that case, I suggest you to create an Azure Support ticket to take a closer look at internal diagnostics of your app gateway instance considering it's still occurring after troubleshooting. AppGW is a PaaS instance , by default you wont get access to the Applicaiton Gateway. And each pool has 2 servers . Which language's style guidelines should be used when writing code that is supposed to be called from another language? Public domain name resolution might be required in scenarios where Application Gateway must reach out to external domains like OCSP servers or to check the certificates revocation status. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Design a site like this with WordPress.com, Troubleshoot backend health issues in Azure Application Gateway | Microsoft Docs. To verify, you can use OpenSSL commands from any client and connect to the backend server by using the configured settings in the Application Gateway probe. Check the document page that's provided in step 3a to learn more about how to create NSG rules. @sajithvasu I would continue to work with the support engineers while they look deeper into your authentication certificate. OpenSSL s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts. This happens when an NSG/UDR/Firewall on the application gateway subnet is blocking traffic on ports 65503-65534 in case of v1 SKU, and ports 65200-65535 in case of the v2 SKU or if the FQDN configured in the backend pool could not be resolved to an IP address. rev2023.5.1.43405. When I use v2 SKU with the option to trust the backend certificate from APIM it works. The error says that Root cert is not whitelisted on the AppGW , but you might have a valid Third party certificate on the backend , and more over if you try to access the backend directly bypassing the Application Gateway you will not see any issues related to certificate in the browser. The following steps help you export the .cer file for your certificate: Use the steps 1 - 8 mentioned in the previous section Export authentication certificate (for v1 SKU) to export the public key from your backend certificate. In this example, you'll use a TLS/SSL certificate for the backend certificate and export its public key to be used as authentication certification. To learn more, see our tips on writing great answers. Now Clients will check the Server certificate and confirm if the certificate is issued by Trusted root or not. The v2 SKU is not an option at the moment due to lack of UDR support. Visual Studio Code How to Change Theme ? when the backend server cert hits AppGW after Server Hello , AppGW tries to check who issued the certificate and it finds that it was issued by Intermediate certificate but then it does not have information about Intermediate cert, like who issued the cert and what is the root certificate of that intermediate certificate. to your account. If the certificate wasn't issued by a trusted CA (for example, a self-signed certificate was used), users should upload the issuer's certificate to Application Gateway. Which ability is most related to insanity: Wisdom, Charisma, Constitution, or Intelligence? I have two listeners and my issue has started on one of them when SSL certificate has been renewed. To learn more visit https://aka.ms/authcertificatemismatch". We have not faced any issues with HTTP sites but we are facing issues with end-to-end SSL. -> Same certificate with private key from applicaton server. This can create problems when uploaded the text from this certificate to Azure. Your email address will not be published. An authentication certificate is required to allow backend instances in Application Gateway v1 SKU. Unfortunately I have to use the v1 for this set-up. Default route advertised by the ExpressRoute/VPN connection to the virtual network over BGP: a. This is the exact thing what we do when import .CER file in the HTTP Settings of the Application Gateway. There is certificate with private key as PFX on listenner settings. During SSL negotiation , Client sends "Client Hello" and Server Responds with "Server Hello" with its Certificate to the Client. Message: Time taken by the backend to respond to application gateway's health probe is more than the timeout threshold in the probe setting. d. If an NSG is configured, search for that NSG resource on the Search tab or under All resources. In this example, requests using TLS1.2 are routed to backend servers in Pool1 using end to end TLS. The application is listeing in port 443. Cause: End-to-end SSL with Application Gateway v2 requires the backend server's certificate to be verified in order to deem the server Healthy. The intermediate certificate(s) should be bundled with server certificate and installed on the backend server. From the properties displayed, find the CN of the certificate and enter the same in the host name field of the http settings. To automate the approach above, within my template I extracted the .cer and .pfx into base64 string using the below PowerShell command: This gave me the ability to upload this into Key Vault, and reference the Secret within my template parameter file, so no credentials or keys are stored in templates, theyre all in Key Vault (all kinds of secure). Do not edit this section. How did you verify the cert? Is "I didn't think it was serious" usually a good defence against "duty to rescue"? If thats not a desired value, you should create a custom probe and associate it with the HTTP settings. I will clean-up some of my older comments to keep it generic to all since the issue has been identified. I have some questions in regards to application gateway and need help with the same : 1)Is that application gateway can be configured with multiple backend pools and each pool can serve a request for different applications ? craigclouditpro your a lifesaver thanks for posting this friend ! The backend certificate can be the same as the TLS/SSL certificate or different for added security. But when we have multiple chain certificate and if your backend application/server sends only the leaf the certificate , AppGW will not be able to trust the cert up to the top level domain root. The exported certificate looks similar to this: If you open the exported certificate using Notepad, you see something similar to this example. The application gateway then tries to connect to the server on the TCP port mentioned in the HTTP settings. Configuration details on Applicaiton Gateway: i am stuck with that issue, i am thinking maybe it can be a bug but can not be sure. Configure that certificate on your backend server. @TravisCragg-MSFT: Any luck? multiple chain certificate and if your backend application/server sends only the leaf the certificate , AppGW . Cause: After the TCP connection has been established and a TLS handshake is done (if TLS is enabled), Application Gateway will send the probe as an HTTP GET request to the backend server. But when we have multiple chain certificate and your backend application is sending the Application Gateway only the leaf the certificate , AppGW will not be able to trust the cert up to the top level domain root. We initially faced an issue with the certificate on the backend server which has since been sorted out by MS Support. Otherwise, it will be marked as Unhealthy with this message. For example: If the server returns any other status code, it will be marked as Unhealthy with this message. @EmreMARTiN , you mentioned your backend certificate is from "Digicert" which is already a well-known trusted CA. An issue with your configuration needs to be ruled out first. 566), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. For the server certificate to be trusted we need the Root certificate in Trusted Root Cert Store , usually if you are having certs issued by Godaddy,Digicert,Vergion like Third party Vendors you dont have to do anything because they are automatically trusted by your client/browser. For details on this Openssl command you can refer toTroubleshoot backend health issues in Azure Application Gateway | Microsoft Docs , Look for the sub topic Trusted root certificate mismatch. Now use steps 2-9 mentioned in the section Export authentication certificate from a backend certificate (for v1 SKU) above to export the trusted root certificate in the Base-64 encoded X.509(.CER) format. I just set it up and cannot get the health probe for HTTPS healthy. However, we need few details. To Answer we need to understand what happens in any SSL/TLS negotiation. Verify that the FQDN entered in the backend pool is correct and that it's a public domain, then try to resolve it from your local machine. Check the backend server's health and whether the services are running. probe setting. In 5e D&D and Grim Hollow, how does the Specter transformation affect a human PC in regards to the 'undead' characteristics and spells? Were you able to reproduce this scenario and check? To do the whitlisting, you will need to export APIM SSL certificate into a Base-64 encoded (CER) format, and apply the exported certificate in (Backend authentication certificates) under the Application Gateway's HTTP settings configured for the APIM. I am using the base64 encoded .CER file without the chain (w/o intermediary and root) at the https setting of the backend settings of application gateway and it is working fine (see image below). You should do this only if the backend has cert which is issued by internal CA, I hope we are clear till now on why we import Authenticate cert in the HTTP settings of the AppGW and when we use the option "Use Well Known CA", But the actual problem arises if you are using a Third party Cert or Internal CA Cert which has Intermediate CA and then Leaf certificate, Most of the orgs for security reasons use Root Cert----> Intermediate Cert ------> Leaf Cert , even Microsoft follows the same for bing , you can check yourself as below, Now lets discuss what exactly is the confusion here if we have multiple Chain Cert, Check this below when you have single chain certificate , then there will be no confusion with appgw , if your root CA is Global trusted just select "Use Trusted Root CA" option in HTTPsettings, If you root CA is Internal CA , then import that Top root cert in .cer format and upload it in the HTTP settings. Application Gateway must be restarted after any modification to the backend server DNS entries to begin to use the new IP addresses. applications. This month for new environment build we started encountering this problem. For example, run the following command: Test-NetConnection -ComputerName www.bing.com -Port 443. Select the setting that has the expired certificate, select, The NSG on the Application Gateway subnet is blocking inbound access to ports 65503-65534 (v1 SKU) or 65200-65535 (v2 SKU) from Internet. Note that this .CER file must match the certificate (PFX) deployed at the backend application. By clicking Sign up for GitHub, you agree to our terms of service and Version Independent ID: d85aa8fe-7270-d073-ea56-d1c0759383b8. Our current setup includes app gateway v1 SKU integrated with app services having custom domain enabled. When calculating CR, what is the damage per turn for a monster with multiple attacks? Message: Body of the backend's HTTP response did not match the If probes are routed through a virtual appliance and modified, the backend resource will display a 200 status code and the Application Gateway health status can display as Unknown. Can you please add reference to relevant Microsoft Docs page you are following? Next hop: Internet. Configure that certificate on your backend server. 10.0.0.4 = IP of backend server (if using DNS ensure it points to backend server and not the public IP of appgw). The current data must be within the valid from and valid to range. Page not found. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I will now proceed to close this github issue here since this repo is for MS Docs specifically. After you've figured out the time taken for the application to respond, select the. More info about Internet Explorer and Microsoft Edge, Export trusted root certificate (for v2 SKU), Overview of TLS termination and end to end TLS with Application Gateway, Application Gateway diagnostics and logging. Azure Applicaiton Gateway V2 Certification Issue, https://docs.microsoft.com/en-us/azure/application-gateway/certificates-for-backend-authentication#export-trusted-root-certificate-for-v2-sku, https://docs.microsoft.com/en-us/azure/application-gateway/ssl-overview#end-to-end-tls-with-the-v2-sku, Enabling end to end TLS on Azure Application Gateway, articles/application-gateway/ssl-overview.md, https://docs.microsoft.com/en-us/azure/cloud-shell/overview. In this article I am going to talk about one most common issue "backend certificate not whitelisted" If the output doesnt show the complete chain of the certificate being returned, export the certificate again with the complete chain, including the root certificate. Solution: If you receive this error message, there's a mismatch between the certificate that has been uploaded to Application Gateway and the one that was uploaded to the backend server. Required fields are marked *. If the output doesn't show the complete chain of the certificate being returned, export the certificate again with the complete chain, including the root certificate. The other one which certificate is still valid and does not need renewal is green. Sorry my bad, this is actually now working - I just needed to have the CN in the certificate match with what was set in backend pool. This article describes the symptoms, cause, and resolution for each of the errors shown. Do not edit this section. Hi @TravisCragg-MSFT : Were you able to check this? Now how do we find if my application/backendserver is sending the complete chain to AppGW? This doesn't indicate an error. Find centralized, trusted content and collaborate around the technologies you use most. Application Gateway doesn't provide you any mechanism to create or purchase a TLS/SSL certificate. @sajithvasu My apologies for this taking a long time, but there are some strange issues here(as you have already discovered). OpenSSL s_client -connect 10.0.0.4:443 -servername www.example.com -showcerts. Solution: If you receive this error message, there's a mismatch between the certificate that has been uploaded to Application Gateway and the one that was uploaded to the backend server. I had this same issue. To learn more visit https://aka.ms/authcertificatemismatch" I have some questions in regards to application gateway and need help with the same : For example, check whether the database has any issues that might trigger a delay in response. We should get one Linux machine which is in the same subnet/VNET of the backend application and run the following commands. There is ROOT certificate on httpsettings. I can confirm that it's NOT a general issue or bug of the product. Ensure that you add the correct root certificate to whitelist the backend". This operation can be completed via Azure PowerShell or Azure CLI. To learn more visit - https://aka.ms/UnknownBackendHealth. Choose the destination manually as any internet-routable IP address like 1.1.1.1. Now you may ask why it works when you browse the backend directly through browser. Already on GitHub? You should do this only if the backend has cert which is issued by internal CA, I hope we are clear till now on why we import Authenticate cert in the HTTP settings of the AppGW and when we use the option Use Well Known CA, But the actual problem arises if you are using a Third party Cert or Internal CA Cert which has Intermediate CA and then Leaf certificate, Most of the orgs for security reasons use Root Cert-> Intermediate Cert > Leaf Cert , even Microsoft follows the same for bing , check the screenshot below, Now lets discuss what exactly is the confusion here if we have multiple Chain Cert, When you have single chain certificate , then there will be no confusion with appgw , if your root CA is Global trusted just select Use Trusted Root CA option in HTTPsettings, If you root CA is Internal CA , then import that Top root cert in .cer format and upload it in the HTTP settings. If it is, check the DNS server about why it can't resolve to the IP address of the specified FQDN. Most of the browsers are thick clients , so it may work in the new browsers but reverse proxies like Application Gateway wont behave like our browsers they only trust the certificates if the backend sends the complete chain. Does a password policy with a restriction of repeated characters increase security? If you have properly added the certificate, and the backend pool is pointing to the custom domain (not the azurewebsites.net domain), then your best options are to either try the V2 SKU, or open a support request to troubleshoot further. Cause: When you create a custom probe, you can mark a backend server as Healthy by matching a string from the response body. Azure Tip #10 Load Balancer vs Traffic Manager, Azure Tip #2 Azure Free Subscription without CreditCard for Learning Sandbox, Azure Charts All about Azure news, stats, and Changes, 100 Multiple Choice Questions & Answers on Microsoft Outlook, 100 Multiple Choice Questions & Answers on PowerPoint. The text was updated successfully, but these errors were encountered: @sajithvasu I am not aware of any changes that have been made on the App Gateway side that would make this not work. Cause: Every certificate comes with a validity range, and the HTTPS connection won't be secure unless the server's TLS/SSL certificate is valid. To troubleshoot this issue, check the Details column on the Backend Health tab. Best practices and the latest news on Microsoft FastTrack, The employee experience platform to help people thrive at work, Expand your Azure partner-to-partner network, Bringing IT Pros together through In-Person & Virtual events. Applicaiton works fine on the backend servers with 443 certificate from Digicert. Azure Tip #5 Change Color Theme in Azure Portal, Azure Tip #1 Azure Services offered by Microsoft, Azure Tip #8 Fix Data for certificate is Invalid error, Azure Tip #6 Reset the Microsoft Azure Dashboard. Received response body doesn't contain {string}. @EmreMARTiN , following up to see if the support case resolved your issue. Save the custom probe settings and check whether the backend health shows as Healthy now. Service:<---> Certificates signed by well known CA authorities whose CN matches the host name in the HTTP backend settings do not require any additional step for end to end TLS to work. In each case, if the backend server doesn't respond successfully, Application Gateway marks the server as Unhealthy and stops forwarding requests to the server. Thank you everyone. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Application Gateway is in an Unhealthy state. Your email address will not be published. If you've already registered, sign in. -verify error:num=19:self signed certificate in certificate chain Cause: After the DNS resolution phase, Application Gateway tries to connect to the backend server on the TCP port that's configured in the HTTP settings. For more information about how to extract and upload Trusted Root Certificates in Application Gateway, see Export trusted root certificate (for v2 SKU). Now Clients will check the Server certificate and confirm if the certificate is issued by Trusted root or not. Azure Tip #3 What is Scale up and Scale Out ? During SSL negotiation , Client sends "Client Hello" and Server Responds with "Server Hello" with its Certificate to the Client. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Expected:{HTTPStatusCode0} Received:{HTTPStatusCode1}. Then, click Next. On the Export File Format page, select Base-64 encoded X.509 (.CER)., and then click Next. If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? The -servername switch is used in shared hosting environments. In this article I am going to talk about one most common issue "backend certificate not whitelisted", If you check the backend health of the application gateway you will see the error like this "The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. Have a question about this project? If there's a custom DNS server configured on the virtual network, verify that the servers can resolve public domains. To allow this access, upload trusted root certificates (for v2 SKU) of the back-end servers to the application gateway. Fast-forward 2022, we are also faced with the same issue and getting the same error "Backend server certificate is not whitelisted with Application Gateway" using Application Gateway v1. site bindings in IIS, server block in NGINX and virtual host in Apache. You should do this only if the backend has cert which is issued by internal CA, I hope we are clear till now on why we import Authenticate cert in the HTTP settings of the AppGW and when we use the option "Use Well Known CA", But the actual problem arises if you are using a Third party Cert or Internal CA Cert which has Intermediate CA and then Leaf certificate, Most of the orgs for security reasons use Root Cert----> Intermediate Cert ------> Leaf Cert , even Microsoft follows the same for bing , check the screenshot below, Now lets discuss what exactly is the confusion here if we have multiple Chain Cert, When you have single chain certificate , then there will be no confusion with appgw , if your root CA is Global trusted just select "Use Trusted Root CA" option in HTTPsettings, If you root CA is Internal CA , then import that Top root cert in .cer format and upload it in the HTTP settings. Now, this is the frustrating partwithin IIS, all of my sites are bound too each specified certificate (sharing a single cert across all the sites wont work for this scenario because of the difference in SSL and URL names), What the MSFT document (https://docs.microsoft.com/en-us/azure/application-gateway/application-gateway-end-to-end-ssl-powershell) fails to tell you, is that you need a Default SITE binding to a certificate, without SNI ticked. This approach is useful in situations where the backend website needs authentication. My issue was due to the root certificate not being presented to appgw, and resulted in the error: "The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. New blog articles in Microsoft Tech Community, Troubleshoot backend health issues in Azure Application Gateway | Microsoft Docs, Set up Granular Delegated Admin Privileges in Microsoft 365 Lighthouse, Data Mapper Patterns: Conditional Mapping, Windows Server Summit 2022: Modernize your Apps with Windows Containers and AKS, Kubernetes External DNS for Azure DNS & AKS, Update: Addressing Karis Law and Ray Baums Act with Microsoft Teams phone system, SSIS Always on AG (Availability Group) and Error Please Create a Master Key, Azure Marketplace new offers January 4, 2023. The Standard and WAF SKU (v1) Server Name Indication (SNI) is set as the FQDN in the backend pool address. Check the backend server's health and whether the services are running. I guess you need a Default SITE binding to a certificate, without SNI ticked. Message: The root certificate of the server certificate used by the backend does not match the trusted root certificate added to the application gateway. PS : Dont forget to upload the CER file to the HTTP settings in ApplicationGateway before you do the Health Check. Most of the best practice documentation involves the V2 SKU and not the V1. For a TLS/SSL certificate to be trusted, the backend server certificate must be issued by a CA that's included in the trusted store of Application Gateway. At the time of writing the Application Gateway doesnt support uploading the Certificates directly into Key Vault, hence extracting the string into .txt and dumping it in Key Vault Secrets. Only HTTP status codes of 200 through 399 are considered healthy. During SSL negotiation , Client sends Client Hello and Server Responds with Server Hello with its Certificate to the Client. How to Restart Windows Explorer Process in Windows 11?
