X509_REQ_add1_attr_by_NID
if (!X509_REQ_add1_attr_by_NID(req, nid, chtype,
rv = X509_REQ_add1_attr_by_NID(req, nid, V_ASN1_SEQUENCE, ext, extlen);
int X509_REQ_add1_attr_by_NID(X509_REQ *req,