According to the relevant standards, the valid range for SM2 private
keys is [1, n-1), where n is the order of the curve generator.
For this reason we cannot reuse the EC validation function as it is, and
we introduce a new internal function `sm2_key_private_check()`.
Partially fixes https://github.com/openssl/openssl/issues/8435
Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/13359)
Use EVP_PKEY_set_alias_type to access
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6443)
