X509_LOOKUP_add_dir
if (X509_LOOKUP_add_dir(lookup, CApath, X509_FILETYPE_PEM) <= 0) {
X509_LOOKUP_add_dir(lookup, NULL, X509_FILETYPE_DEFAULT);
if (X509_LOOKUP_add_dir(lookup, CApath, X509_FILETYPE_PEM) <= 0) {
X509_LOOKUP_add_dir(lookup, NULL, X509_FILETYPE_DEFAULT);
|| X509_LOOKUP_add_dir(lookup, path, X509_FILETYPE_PEM) <= 0)
X509_LOOKUP_add_dir(lookup, NULL, X509_FILETYPE_DEFAULT);