/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by ThinkSec AS and
 * NAI Labs, the Security Research Division of Network Associates, Inc.
 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
 * DARPA CHATS research program.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include <ctype.h>
#include <grp.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PAM_SM_ACCOUNT

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
#include <security/openpam.h>

PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
    int argc __unused, const char *argv[] __unused)
{
        struct passwd *pwd;
        struct group *grp;
        const char *user;
        int pam_err, found, allow;
        char *line, *name, **mem;
        size_t len, ulen;
        FILE *f;

        pam_err = pam_get_user(pamh, &user, NULL);
        if (pam_err != PAM_SUCCESS)
                return (pam_err);
        if (user == NULL || (pwd = getpwnam(user)) == NULL)
                return (PAM_SERVICE_ERR);

        found = 0;
        ulen = strlen(user);
        if ((f = fopen(_PATH_FTPUSERS, "r")) == NULL) {
                PAM_LOG("%s: %m", _PATH_FTPUSERS);
                goto done;
        }
        while (!found && (line = fgetln(f, &len)) != NULL) {
                if (*line == '#')
                        continue;
                while (len > 0 && isspace(line[len - 1]))
                        --len;
                if (len == 0)
                        continue;
                /* simple case first */
                if (*line != '@') {
                        if (len == ulen && strncmp(user, line, len) == 0)
                                found = 1;
                        continue;
                }
                /* member of specified group? */
                asprintf(&name, "%.*s", (int)len - 1, line + 1);
                if (name == NULL) {
                        fclose(f);
                        return (PAM_BUF_ERR);
                }
                grp = getgrnam(name);
                free(name);
                if (grp == NULL)
                        continue;
                for (mem = grp->gr_mem; mem && *mem && !found; ++mem)
                        if (strcmp(user, *mem) == 0)
                                found = 1;
        }
 done:
        allow = (openpam_get_option(pamh, "disallow") == NULL);
        if (found)
                pam_err = allow ? PAM_SUCCESS : PAM_AUTH_ERR;
        else
                pam_err = allow ? PAM_AUTH_ERR : PAM_SUCCESS;
        if (f != NULL)
                fclose(f);
        return (pam_err);
}

PAM_MODULE_ENTRY("pam_ftpusers");