void silc_hmac_make_with_key(SilcHmac hmac, unsigned char *data,
                                 SilcUInt32 data_len,
                                 unsigned char *key, SilcUInt32 key_len,
                                 unsigned char *return_hash,
                                 SilcUInt32 *return_len);

    Same as the silc_hmac_make but takes the key for the HMAC as
    argument.  If this is used the key that may have been set by calling
    silc_hmac_set_key is ignored.