HTTPS Mutual Auth HTTP 400 Response "400 No required SSL certificate was sent"Issue When trying to authenticate with an external API endpoint that uses HTTPS Mutual Authentication you may see a HTTP 400 response 'No required SSL certificate was sent': <html> <head><title>400 No required SSL certificate was sent</title></head> <body> <center><h1>400 Bad Request</h1></center> <center>No required SSL certificate was sent</center> <hr><center>server</center> </body> </html>ReleaseAll ServiceNow releasesCauseA configuration issue in the HTTPS Mutual Auth configuration on the ServiceNow instanceResolutionEnsure that the Keystore you're using contains a public/private keypair. The public key should have been signed by a CA that the other side (the server) trusts for mutual authentication. The private key should have the same passphrase on it as the passphrase used to open the keystore fileExport these two System Property records to XML as a backup, and then delete them:glide.httpclient.protocol.<profile_name>.class = "com.glide.certificates.DBKeyStoreSocketFactory"glide.httpclient.protocol.<profile_name>.port = "<port>"Related LinksSee also: Setting up Mutual Authentication for Web Services: https://support.servicenow.com/kb_view.do?sysparm_article=KB0696002 Mutual Authentication: Overview: https://support.servicenow.com/kb_view.do?sysparm_article=KB0691876 Steps to set up Mutual Authentication: Keys: https://support.servicenow.com/kb_view.do?sysparm_article=KB0696776 Debugging Mutual Authentication: https://support.servicenow.com/kb_view.do?sysparm_article=KB0696599