private static extern int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX ctx, EVP_PKEY_type keyType, EVP_PKEY_Ctrl_OP optype, EVP_PKEY_Ctrl_Command cmd, int p1, IntPtr p2);
private static extern EVP_PKEY_CTX EVP_PKEY_CTX_new_id(EVP_PKEY_type id, IntPtr e);
internal static extern EVP_PKEY_CTX EVP_PKEY_CTX_new_id(EVP_PKEY_type id, IntPtr e);
private static extern int EVP_PKEY_assign(EVP_PKEY pkey, EVP_PKEY_type keyType, EC_KEY key);
internal static extern int EVP_PKEY_assign(EVP_PKEY pkey, EVP_PKEY_type keyType, IntPtr key);
internal static extern unsafe int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX ctx, EVP_PKEY_type keyType, EVP_PKEY_Ctrl_OP optype, EVP_PKEY_Ctrl_Command cmd, int p1, void *p2);