This function clears the cache of provider key references, and is used
in evp_keymgmt_export_to_provider() when the internal key is dirty, as
well as by EVP_PKEY_free_it().
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9312)
This function is used to transport private key materia from whatever
is already attached to the EVP_PKEY to the new provider, using key
data export and import functionality.
If a legacy lower level key has been assigned to the EVP_PKEY, we use
its data to create a provider side key, and thereby have a bridge
between old style public key types and the EVP_PKEY on providers.
If successful, this function returns a reference to the appropriate
provider side data for the key.
This can be used by any operation that wants to use this key.
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9312)
