granicus.if.org Git - linux-pam/blob - libpam/pam_start.c

   1 /* pam_start.c */
   2
   3 /* Creator Marc Ewing
   4  * Maintained by AGM
   5  *
   6  * $Id$
   7  *
   8  */
   9
  10 #include "pam_private.h"
  11
  12 #include <ctype.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <string.h>
  16 #include <syslog.h>
  17
  18 int pam_start (
  19     const char *service_name,
  20     const char *user,
  21     const struct pam_conv *pam_conversation,
  22     pam_handle_t **pamh)
  23 {
  24     D(("called pam_start: [%s] [%s] [%p] [%p]"
  25        ,service_name, user, pam_conversation, pamh));
  26
  27     if (pamh == NULL) {
  28         _pam_system_log(LOG_CRIT, "pam_start: invalid argument: pamh == NULL");
  29         return (PAM_BUF_ERR);
  30     }
  31
  32     if ((*pamh = calloc(1, sizeof(**pamh))) == NULL) {
  33         _pam_system_log(LOG_CRIT, "pam_start: calloc failed for *pamh");
  34         return (PAM_BUF_ERR);
  35     }
  36
  37     /* All service names should be files below /etc/pam.d and nothing
  38        else. Forbid paths. */
  39     if (strrchr(service_name, '/') != NULL)
  40         service_name = strrchr(service_name, '/') + 1;
  41
  42     /* Mark the caller as the application - permission to do certain
  43        things is limited to a module or an application */
  44
  45     __PAM_TO_APP(*pamh);
  46
  47     if (service_name) {
  48         char *tmp;
  49
  50         if (((*pamh)->service_name = _pam_strdup(service_name)) == NULL) {
  51             _pam_system_log(LOG_CRIT,
  52                             "pam_start: _pam_strdup failed for service name");
  53             _pam_drop(*pamh);
  54             return (PAM_BUF_ERR);
  55         }
  56         for (tmp=(*pamh)->service_name; *tmp; ++tmp)
  57             *tmp = tolower(*tmp);                   /* require lower case */
  58     } else
  59         (*pamh)->service_name = NULL;
  60
  61     if (user) {
  62         if (((*pamh)->user = _pam_strdup(user)) == NULL) {
  63             _pam_system_log(LOG_CRIT,
  64                             "pam_start: _pam_strdup failed for user");
  65             _pam_drop((*pamh)->service_name);
  66             _pam_drop(*pamh);
  67             return (PAM_BUF_ERR);
  68         }
  69     } else
  70         (*pamh)->user = NULL;
  71
  72     (*pamh)->tty = NULL;
  73     (*pamh)->prompt = NULL;              /* prompt for pam_get_user() */
  74     (*pamh)->ruser = NULL;
  75     (*pamh)->rhost = NULL;
  76     (*pamh)->authtok = NULL;
  77     (*pamh)->oldauthtok = NULL;
  78     (*pamh)->fail_delay.delay_fn_ptr = NULL;
  79     (*pamh)->former.choice = PAM_NOT_STACKED;
  80
  81     if (pam_conversation == NULL
  82         || ((*pamh)->pam_conversation = (struct pam_conv *)
  83             malloc(sizeof(struct pam_conv))) == NULL) {
  84         _pam_system_log(LOG_CRIT, "pam_start: malloc failed for pam_conv");
  85         _pam_drop((*pamh)->service_name);
  86         _pam_drop((*pamh)->user);
  87         _pam_drop(*pamh);
  88         return (PAM_BUF_ERR);
  89     } else {
  90         memcpy((*pamh)->pam_conversation, pam_conversation,
  91                sizeof(struct pam_conv));
  92     }
  93
  94     (*pamh)->data = NULL;
  95     if ( _pam_make_env(*pamh) != PAM_SUCCESS ) {
  96         _pam_system_log(LOG_ERR,"pam_start: failed to initialize environment");
  97         _pam_drop((*pamh)->service_name);
  98         _pam_drop((*pamh)->user);
  99         _pam_drop(*pamh);
 100         return PAM_ABORT;
 101     }
 102
 103     _pam_reset_timer(*pamh);         /* initialize timer support */
 104
 105     _pam_start_handlers(*pamh);                   /* cannot fail */
 106
 107     /* According to the SunOS man pages, loading modules and resolving
 108      * symbols happens on the first call from the application. */
 109
 110     if ( _pam_init_handlers(*pamh) != PAM_SUCCESS ) {
 111         _pam_system_log(LOG_ERR, "pam_start: failed to initialize handlers");
 112         _pam_drop_env(*pamh);                 /* purge the environment */
 113         _pam_drop((*pamh)->service_name);
 114         _pam_drop((*pamh)->user);
 115         _pam_drop(*pamh);
 116         return PAM_ABORT;
 117     }
 118
 119     D(("exiting pam_start successfully"));
 120
 121     return PAM_SUCCESS;
 122 }