_krb5_internal_hmac
ret = _krb5_internal_hmac(context, c, tmp, sizeof(tmp), 0, &ksign, result);
ret = _krb5_internal_hmac(NULL, c, t, sizeof(t), 0, key, &k1_c);
ret = _krb5_internal_hmac(NULL, c, cdata + 16, len - 16, 0, &ke, &cksum);
ret = _krb5_internal_hmac(NULL, c, data, 16, 0, &ke, &k3_c);
ret = _krb5_internal_hmac(NULL, c, t, sizeof(t), 0, key, &k1_c);
ret = _krb5_internal_hmac(NULL, c, cdata, 16, 0, &ke, &k3_c);
ret = _krb5_internal_hmac(NULL, c, cdata + 16, len - 16, 0, &ke, &cksum);
ret = _krb5_internal_hmac(context, c, signature, sizeof(signature),
ret = _krb5_internal_hmac(context, c, data, len, usage, &kd, result);
ret = _krb5_internal_hmac(context, c, data, len, usage, key, &res);
_krb5_internal_hmac (