X509_STORE_CTX_set_flags
X509_STORE_CTX_set_flags(xsc, X509_V_FLAG_CHECK_SS_SIGNATURE);
void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags);
X509_STORE_CTX_set_flags(xs_ctx,
X509_STORE_CTX_set_flags(ctx, tls1_suiteb(s));