libinnauth - Routines for writing nnrpd resolvers and authenticators

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

       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 structauth_info or
       structres_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 structres_info
       actually point to instances of structsockaddr_in (or structsockaddr_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.

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

       libinnauth - Routines for writing nnrpd resolvers and authenticators

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

INN 2.7.3                                          2025-05-19                                      libinnauth(3)

           #include "libinnauth.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*);