NAME

       libauth - routines for writing nnrpd resolvers and authenticators

SYNOPSIS

           #include "libauth.h"

           struct res_info {
               struct sockaddr *client;
               struct sockaddr *local;
               char *clienthostname;
           };

           struct auth_info {
               char *username;
               char *password;
           };

           struct auth_info *get_auth_info(FILE *);
           struct res_info  *get_res_info (FILE *);

           void free_auth_info(struct auth_info*);
           void free_res_info (struct res_info*);

DESCRIPTION

       These functions provide a convenient C frontend to the nnrpd external authentication
       interface documented in doc/external-auth.  Use of this library is not required; in
       particular, external resolvers and authenticators written in languages other than C will
       need to implement the necessary functionality themselves.

       The get_auth_info() and get_res_info() functions allocate sufficient memory for a struct
       auth_info or struct res_info and any necessary fields, and return a pointer to the struct
       with the fields filled in from information supplied by nnrpd (the FILE* parameter
       generally should be "stdin").  Both functions return NULL on error.  The caller is
       responsible for deallocating the memory by using the functions below.

       The string fields of both structs are straightforward.  The client and local fields of
       struct res_info actually point to instances of struct sockaddr_in (or struct sockaddr_in6
       if IPv6 support is compiled in).

       The free_auth_info() and free_res_info() functions free the struct passed in as argument
       and all necessary fields.

BUGS

       In many cases, nnrpd provides more information than is normally useful (for example, even
       when calling an authenticator, the resolver information is often provided.)  On the other
       hand, in certain cases it provides less information than might be expected (for example,
       if nnrpd is reading from stdin rather than a socket).  The implementation is capable of
       handling at least the first of these issues, but that functionality is not exposed in the
       interface.

       At present, libauth.h and its implementation are located in authprogs/; perhaps they
       should be moved to include/ and lib/, respectively?

HISTORY

       Written by Jeffrey M. Vinocur <jeff@litech.org> for InterNetNews.

SEE ALSO

       nnrpd(8), readers.conf(5), doc/external-auth