find_sig_alg
find_sig_alg(const heim_oid *oid);
md = find_sig_alg(&alg->algorithm);
md = find_sig_alg(&alg->algorithm);
md = find_sig_alg(&alg->algorithm);
md = find_sig_alg(&alg->algorithm);
md = find_sig_alg(key->signature_alg);
sig = find_sig_alg(&sig_alg->algorithm);
static const SIGALG_LOOKUP *find_sig_alg(SSL_CONNECTION *s, X509 *x, EVP_PKEY *pkey);
if (find_sig_alg(s, x, pk) != NULL)
lu = find_sig_alg(s, NULL, NULL);