Syntax
#define FN_OID_GET_ATTR1(FN_NAME, TYPE_T, TYPE_NAME, ATTR1_TYPE, ATTR1) \
int FN_NAME( const mbedtls_asn1_buf *oid, ATTR1_TYPE * ATTR1 ) \
{ \
const TYPE_T *data = oid_ ## TYPE_NAME ## _from_asn1( oid ); \
if( data == NULL ) return( MBEDTLS_ERR_OID_NOT_FOUND ); \
*ATTR1 = data->ATTR1; \
return( 0 ); \
}