preauthcustom.c

   1 /*
   2 ** Copyright 1998 - 2000 Double Precision, Inc.  See COPYING for
   3 ** distribution information.
   4 */
   5
   6 #if HAVE_CONFIG_H
   7 #include "courier_auth_config.h"
   8 #endif
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <errno.h>
  13 #include <pwd.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17
  18 #include        "auth.h"
  19 #include        "authcustom.h"
  20 #include        "courierauthdebug.h"
  21
  22
  23 int auth_custom_pre(const char *userid, const char *service,
  24         int (*callback)(struct authinfo *, void *),
  25                         void *arg)
  26 {
  27         return (authcustomcommon(userid, 0, callback, arg));
  28 }
  29
  30 static int do_auth_custom(const char *, struct authinfo *);
  31
  32 int authcustomcommon(const char *user, const char *pass,
  33         int (*callback)(struct authinfo *, void *),
  34                         void *arg)
  35 {
  36         struct authinfo auth;
  37         int rc;
  38
  39         memset(&auth, 0, sizeof(auth));
  40
  41         rc=do_auth_custom(user, &auth);
  42
  43         if (rc)
  44                 return (rc);
  45
  46         if (pass == 0)
  47                 return (0);     /* Just get the authentication info */
  48
  49         if (auth.clearpasswd)
  50         {
  51                 if (strcmp(pass, auth.clearpasswd))
  52                         return (-1);
  53         }
  54         else
  55         {
  56                 const char *p=auth.passwd;
  57
  58                 if (!p || authcheckpassword(pass, p))
  59                         return (-1);
  60         }
  61
  62         auth.clearpasswd=pass;
  63         return ((*callback)(&auth, arg));
  64 }
  65
  66 static int do_auth_custom(const char *userid, struct authinfo *authinfo)
  67 {
  68         /*
  69         ** Insert custom authentication code here.  This code must obtain
  70         ** authentication information for account 'userid'.
  71         **
  72         ** If you need to link with specific external libraries (-lnsl_s,
  73         ** et al), you'll just have to bite the bullet, install automake
  74         ** and autoconf, then set authcustom.libsdep and authcustom_LDADD
  75         ** in Makefile.am
  76         */
  77
  78         /*
  79         ** If userid does not exist, return (-1).
  80         */
  81
  82         DPRINTF("authcustom: nothing implemented in do_auth_custom()");
  83         return (-1);
  84
  85         /*
  86         ** If there is some kind of a system problem, that is you are
  87         ** unable to check whether userid is valid (the back end database
  88         ** is down, or something) return (1).
  89         */
  90
  91         /*
  92         ** Otherwise, initialize the authinfo structure, and return (0).
  93         **
  94         ** NOTES: this function can be called repeated within a single
  95         ** process, in certain contexts.  Do not simply dynamically
  96         ** allocate memory for all the character strings, each time, because
  97         ** the caller WILL NOT free the memory of any dynamically allocated
  98         ** strings.  If you keep dynamically allocating memory, each time,
  99         ** you're going to get a memory leak, somewhere, and YOU'LL FUCK
 100         ** YOURSELF.  What you should do is either use a static buffer,
 101         ** or dynamically allocate some memory, and free that memory on
 102         ** the next function call.
 103         **
 104         ** Additionally:
 105         **
 106         ** If you open any files, you MUST set FD_CLOEXEC bit on any
 107         ** file descriptor you create (open files, sockets, whatnot).
 108         **
 109         ** Someone else might do a fork and an exec, so you need to make
 110         ** sure things get cleaned up, in that event.
 111         **
 112         ** Fields in the auth structure:
 113         **
 114         ** sysusername - REQUIRED - user name, should simply be userid,
 115         **                          unless you know what you're doing.
 116         ** sysuserid - REQUIRED - pointer to the user's uid_t (yes, it's
 117         **                        a pointer).
 118         ** sysgroupid - REQUIRED - gid_t, the group ID of the user.
 119         **
 120         ** homedir - REQUIRED - home directory.
 121         **
 122         ** address - REQUIRED - the 'identity' of the authenticated user,
 123         **                      the e-mail address.  It is acceptable to set
 124         **                      this field also to userid, if you can't think
 125         **                      of anything better to do.
 126         **
 127         ** fullname - OPTIONAL - user's full name.
 128         **
 129         ** maildir - OPTIONAL - user's primary maildir ($HOME/Maildir default)
 130         **
 131         ** quota - OPTIONAL - user's maildir quota (see a README somewhere)
 132         **
 133         ** passwd, clearpasswd - one of these fields must be initialized,
 134         **                       either one is ok.  Initialize clearpasswd
 135         **                       if you store cleartext passwords.  If you
 136         **                       store crypted passwords, initialize passwd.
 137         */
 138 }
 139
 140 void authcustomclose()
 141 {
 142         /*
 143         ** Place any cleanup here.
 144         */
 145 }