lib/libpam/modules/pam_ftpusers/pam_ftpusers.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 2001 Networks Associates Technology, Inc.
   5  * All rights reserved.
   6  *
   7  * This software was developed for the FreeBSD Project by ThinkSec AS and
   8  * NAI Labs, the Security Research Division of Network Associates, Inc.
   9  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
  10  * DARPA CHATS research program.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. The name of the author may not be used to endorse or promote
  21  *    products derived from this software without specific prior written
  22  *    permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $FreeBSD: head/lib/libpam/modules/pam_ftpusers/pam_ftpusers.c 326219 2017-11-26 02:00:33Z pfg $
  37  */
  38
  39 #include <ctype.h>
  40 #include <grp.h>
  41 #include <paths.h>
  42 #include <pwd.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #define PAM_SM_ACCOUNT
  48
  49 #include <security/pam_appl.h>
  50 #include <security/pam_modules.h>
  51 #include <security/pam_mod_misc.h>
  52 #include <security/openpam.h>
  53
  54 PAM_EXTERN int
  55 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
  56     int argc __unused, const char *argv[] __unused)
  57 {
  58         struct passwd *pwd;
  59         struct group *grp;
  60         const char *user;
  61         int pam_err, found, allow;
  62         char *line, *name, **mem;
  63         size_t len, ulen;
  64         FILE *f;
  65
  66         pam_err = pam_get_user(pamh, &user, NULL);
  67         if (pam_err != PAM_SUCCESS)
  68                 return (pam_err);
  69         if (user == NULL || (pwd = getpwnam(user)) == NULL)
  70                 return (PAM_SERVICE_ERR);
  71
  72         found = 0;
  73         ulen = strlen(user);
  74         if ((f = fopen(_PATH_FTPUSERS, "r")) == NULL) {
  75                 PAM_LOG("%s: %m", _PATH_FTPUSERS);
  76                 goto done;
  77         }
  78         while (!found && (line = fgetln(f, &len)) != NULL) {
  79                 if (*line == '#')
  80                         continue;
  81                 while (len > 0 && isspace(line[len - 1]))
  82                         --len;
  83                 if (len == 0)
  84                         continue;
  85                 /* simple case first */
  86                 if (*line != '@') {
  87                         if (len == ulen && strncmp(user, line, len) == 0)
  88                                 found = 1;
  89                         continue;
  90                 }
  91                 /* member of specified group? */
  92                 asprintf(&name, "%.*s", (int)len - 1, line + 1);
  93                 if (name == NULL) {
  94                         fclose(f);
  95                         return (PAM_BUF_ERR);
  96                 }
  97                 grp = getgrnam(name);
  98                 free(name);
  99                 if (grp == NULL)
 100                         continue;
 101                 for (mem = grp->gr_mem; mem && *mem && !found; ++mem)
 102                         if (strcmp(user, *mem) == 0)
 103                                 found = 1;
 104         }
 105  done:
 106         allow = (openpam_get_option(pamh, "disallow") == NULL);
 107         if (found)
 108                 pam_err = allow ? PAM_SUCCESS : PAM_AUTH_ERR;
 109         else
 110                 pam_err = allow ? PAM_AUTH_ERR : PAM_SUCCESS;
 111         if (f != NULL)
 112                 fclose(f);
 113         return (pam_err);
 114 }
 115
 116 PAM_MODULE_ENTRY("pam_ftpusers");