/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1990, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 2002 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * Portions of this software were 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/param.h>
#include <sys/stat.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <pw_scan.h>
#include <libutil.h>

#include "chpass.h"

static int display(const char *tfn, struct passwd *pw);
static struct passwd *verify(const char *tfn, struct passwd *pw);

struct passwd *
edit(const char *tfn, struct passwd *pw)
{
        struct passwd *npw;
        char *line;
        size_t len;

        if (display(tfn, pw) == -1)
                return (NULL);
        for (;;) {
                switch (pw_edit(1)) {
                case -1:
                        return (NULL);
                case 0:
                        return (pw_dup(pw));
                default:
                        break;
                }
                if ((npw = verify(tfn, pw)) != NULL)
                        return (npw);
                free(npw);
                printf("re-edit the password file? ");
                fflush(stdout);
                if ((line = fgetln(stdin, &len)) == NULL) {
                        warn("fgetln()");
                        return (NULL);
                }
                if (len > 0 && (*line == 'N' || *line == 'n'))
                        return (NULL);
        }
}

/*
 * display --
 *      print out the file for the user to edit; strange side-effect:
 *      set conditional flag if the user gets to edit the shell.
 */
static int
display(const char *tfn, struct passwd *pw)
{
        FILE *fp;
        char *bp, *gecos, *p;

        if ((fp = fopen(tfn, "w")) == NULL) {
                warn("%s", tfn);
                return (-1);
        }

        (void)fprintf(fp,
            "#Changing user information for %s.\n", pw->pw_name);
        if (master_mode) {
                (void)fprintf(fp, "Login: %s\n", pw->pw_name);
                (void)fprintf(fp, "Password: %s\n", pw->pw_passwd);
                (void)fprintf(fp, "Uid [#]: %lu\n", (unsigned long)pw->pw_uid);
                (void)fprintf(fp, "Gid [# or name]: %lu\n",
                    (unsigned long)pw->pw_gid);
                (void)fprintf(fp, "Change [month day year]: %s\n",
                    ttoa(pw->pw_change));
                (void)fprintf(fp, "Expire [month day year]: %s\n",
                    ttoa(pw->pw_expire));
                (void)fprintf(fp, "Class: %s\n", pw->pw_class);
                (void)fprintf(fp, "Home directory: %s\n", pw->pw_dir);
                (void)fprintf(fp, "Shell: %s\n",
                    *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
        }
        /* Only admin can change "restricted" shells. */
#if 0
        else if (ok_shell(pw->pw_shell))
                /*
                 * Make shell a restricted field.  Ugly with a
                 * necklace, but there's not much else to do.
                 */
#else
        else if ((!list[E_SHELL].restricted && ok_shell(pw->pw_shell)) ||
            master_mode)
                /*
                 * If change not restrict (table.c) and standard shell
                 *      OR if root, then allow editing of shell.
                 */
#endif
                (void)fprintf(fp, "Shell: %s\n",
                    *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
        else
                list[E_SHELL].restricted = 1;

        if ((bp = gecos = strdup(pw->pw_gecos)) == NULL) {
                warn(NULL);
                fclose(fp);
                return (-1);
        }

        p = strsep(&bp, ",");
        p = strdup(p ? p : "");
        list[E_NAME].save = p;
        if (!list[E_NAME].restricted || master_mode)
          (void)fprintf(fp, "Full Name: %s\n", p);

        p = strsep(&bp, ",");
        p = strdup(p ? p : "");
        list[E_LOCATE].save = p;
        if (!list[E_LOCATE].restricted || master_mode)
          (void)fprintf(fp, "Office Location: %s\n", p);

        p = strsep(&bp, ",");
        p = strdup(p ? p : "");
        list[E_BPHONE].save = p;
        if (!list[E_BPHONE].restricted || master_mode)
          (void)fprintf(fp, "Office Phone: %s\n", p);

        p = strsep(&bp, ",");
        p = strdup(p ? p : "");
        list[E_HPHONE].save = p;
        if (!list[E_HPHONE].restricted || master_mode)
          (void)fprintf(fp, "Home Phone: %s\n", p);

        bp = strdup(bp ? bp : "");
        list[E_OTHER].save = bp;
        if (!list[E_OTHER].restricted || master_mode)
          (void)fprintf(fp, "Other information: %s\n", bp);

        free(gecos);

        (void)fchown(fileno(fp), getuid(), getgid());
        (void)fclose(fp);
        return (0);
}

static struct passwd *
verify(const char *tfn, struct passwd *pw)
{
        struct passwd *npw;
        ENTRY *ep;
        char *buf, *p, *val;
        struct stat sb;
        FILE *fp;
        int line;
        size_t len;

        if ((pw = pw_dup(pw)) == NULL)
                return (NULL);
        if ((fp = fopen(tfn, "r")) == NULL ||
            fstat(fileno(fp), &sb) == -1) {
                warn("%s", tfn);
                free(pw);
                return (NULL);
        }
        if (sb.st_size == 0) {
                warnx("corrupted temporary file");
                fclose(fp);
                free(pw);
                return (NULL);
        }
        val = NULL;
        for (line = 1; (buf = fgetln(fp, &len)) != NULL; ++line) {
                if (*buf == '\0' || *buf == '#')
                        continue;
                while (len > 0 && isspace(buf[len - 1]))
                        --len;
                for (ep = list;; ++ep) {
                        if (!ep->prompt) {
                                warnx("%s: unrecognized field on line %d",
                                    tfn, line);
                                goto bad;
                        }
                        if (ep->len > len)
                                continue;
                        if (strncasecmp(buf, ep->prompt, ep->len) != 0)
                                continue;
                        if (ep->restricted && !master_mode) {
                                warnx("%s: you may not change the %s field",
                                    tfn, ep->prompt);
                                goto bad;
                        }
                        for (p = buf; p < buf + len && *p != ':'; ++p)
                                /* nothing */ ;
                        if (*p != ':') {
                                warnx("%s: line %d corrupted", tfn, line);
                                goto bad;
                        }
                        while (++p < buf + len && isspace(*p))
                                /* nothing */ ;
                        free(val);
                        asprintf(&val, "%.*s", (int)(buf + len - p), p);
                        if (val == NULL)
                                goto bad;
                        if (ep->except && strpbrk(val, ep->except)) {
                                warnx("%s: invalid character in \"%s\" field '%s'",
                                    tfn, ep->prompt, val);
                                goto bad;
                        }
                        if ((ep->func)(val, pw, ep))
                                goto bad;
                        break;
                }
        }
        free(val);
        fclose(fp);

        /* Build the gecos field. */
        len = asprintf(&p, "%s,%s,%s,%s,%s", list[E_NAME].save,
            list[E_LOCATE].save, list[E_BPHONE].save,
            list[E_HPHONE].save, list[E_OTHER].save);
        if (p == NULL) {
                warn("asprintf()");
                free(pw);
                return (NULL);
        }
        while (len > 0 && p[len - 1] == ',')
                p[--len] = '\0';
        pw->pw_gecos = p;
        buf = pw_make(pw);
        free(pw);
        free(p);
        if (buf == NULL) {
                warn("pw_make()");
                return (NULL);
        }
        npw = pw_scan(buf, PWSCAN_WARN|PWSCAN_MASTER);
        free(buf);
        return (npw);
bad:
        free(pw);
        free(val);
        fclose(fp);
        return (NULL);
}