Monitoring Updates to the Twilio REST API Security Settings.Our normal REST API endpoint already supports the strong cipher suites, so you can immediately cut over your production traffic once the changes are verified in your environment. Once you’ve made the necessary changes, verify your upgraded system can connect successfully to the same test endpoint on port 8443 from your production environment, using the same testing procedures. You’ll need to consult with your network administrator if you suspect that is the issue.Įvery environment is different, so we recommend you consult your software package documentation and IT support staff or vendor to thoroughly investigate and upgrade the affected components. In rare cases, you may have a network proxy or firewall that does not support or is not configured correctly for strong cipher suites connections. Note: The Twilio Helper Libraries themselves do not need to be upgraded, but the underlying dependencies that the libraries rely on may need to be updated to a newer version. In other cases, you need to update the underlying application server components used by your HTTP client or helper library (e.g. In most cases, you simply need to upgrade your operating system’s SSL libraries to their latest version. There are a number of components involved in connecting to our REST API that may need to be upgraded or reconfigured to use strong cipher suites: Use Fiddler or similar HTTP debugging tool to view the underlying exception details.

* For the legacy Twilio C#/.NET Helper Library (4.x and lower), failures return as a null response object when there is a low level exception such as SSL negotiation failure. If you can reach from a browser, your network is not blocking traffic.

Tip:Be sure your network allows outbound HTTPS traffic on port 8443 when running the tests.

Connection forcibly closed by the remote host.

These are some common error messages that may indicate your system does not support the security changes:

Notice: Twilio projects can only use the following cipher suites to connect to our API:

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