@deftypefun {int} {gnutls_sign_algorithm_get_requested} (gnutls_session_t @var{session}, size_t @var{indx}, gnutls_sign_algorithm_t * @var{algo}) @var{session}: is a @code{gnutls_session_t} type. @var{indx}: is an index of the signature algorithm to return @var{algo}: the returned certificate type will be stored there Returns the signature algorithm specified by index that was requested by the peer. If the specified index has no data available this function returns @code{GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE} . If the negotiated TLS version does not support signature algorithms then @code{GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE} will be returned even for the first index. The first index is 0. This function is useful in the certificate callback functions to assist in selecting the correct certificate. @strong{Returns:} On success, @code{GNUTLS_E_SUCCESS} (0) is returned, otherwise an error code is returned. @strong{Since:} 2.10.0 @end deftypefun