Beginning on October 2nd, 2017, all tests run with Sauce Labs must use a version of Transport Layer Security (TLS) that supports SNI (Server Name Indication). This change will enhance the security of our service and your testing environment.
SNI was introduced around 2008, and all modern versions of TLS support it. For more information check out this Wikipedia article: https://en.wikipedia.org/wiki/Server_Name_Indication
To make sure SNI is available for your tests, you may have to update the openSSL libraries used by your test runners, or your Selenium language bindings. For example, versions of Java below 7.0 do not support SNI.
If SNI support is not enabled by October 2nd, 2017, the Sauce Labs certificate will not be be validated, which will cause Sauce REST API calls to fail. You may see failures for your Test Runners in your console similar to this:
SSL: certificate subject name '
app.saucelabs.com' does not match target host name 'saucelabs.com'
There are several public sites you can use to verify you are using a version of TLS that supports SNI, for example: