SilcBool silc_idcache_find_by_id(SilcIDCache cache, void *id,
                                     SilcList *ret_list);

    Find ID Cache entry by ID.  This may return multiple entries.
    The entires are returned into the `ret_list' SilcList context.
    Returns TRUE if entry was found.

    If this function is used to find Client ID (SilcClientID), only the
    hash portion of the Client ID is compared.  Use the function
    silc_idcache_find_by_id_one to find exact match for Client ID (full
    ID is compared and not only the hash).

    Comparing only the hash portion of Client ID allows searching of
    Client ID's by nickname, because the hash is based on the nickname.
    As nicknames are not unique, multiple entries may be found.