When running the sas-admin CLI tool against a Viya server on https you may get the following response:

Password> Login failed due to an error with the security certificate. The certificate is signed by an unknown authority. Run with the '--verbose' global option to see additional details.

There is a quick workaround to this, and it can be found when running ./sas-admin help:

GLOBAL OPTIONS:
--colors-enabled Enables or disables ANSI colored output. [$SAS_CLI_COLOR]
--help, -h Shows help.
--insecure, -k Allows connections to TLS sites without validating the server certificates.
--locale "en" Specifies a locale to use. [$LC_ALL, $LANG]
--log-file Specifies the file to write log events to. [$SAS_LOG_FILE]
--output Specifies output format - text, json, fulljson. [$SAS_OUTPUT]
--profile, -p "Default" Specifies a named profile to use. [$SAS_CLI_PROFILE]
--quiet, -q Quiets spurious output, data only.
--sas-endpoint Sets the URL to the SAS services. [$SAS_SERVICES_ENDPOINT]
--verbose Shows detailed processing information and output.
--version, -v Prints the version.

That's right, you can use the -k option to connect, eg as follows:

./sas-admin -k auth login

Happy sassing!