Static CRYPTO_PROVIDER

pub static CRYPTO_PROVIDER: NuCryptoProvider

Global NuCryptoProvider instance.

When the rustls-tls feature is active, call CRYPTO_PROVIDER.default() or
CRYPTO_PROVIDER.set(...) once at startup to pick the CryptoProvider that rustls will use.

Later TLS code gets the provider using get.
If no provider was set or the closure returned an error, get returns a ShellError.