Prevent a null pointer dereference in pw userdel when deleting

[pw-darwin.git] / pw / pw_user.c

/*-
 * Copyright (C) 1996
 *      David L. Nugent.  All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT 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 DAVID L. NUGENT 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.
 * 
 */

#ifndef lint
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <sys/param.h>
#include <dirent.h>
#include <paths.h>
#include <termios.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <login_cap.h>
#include <pwd.h>
#include <grp.h>
#include <libutil.h>
#include "pw.h"
#include "bitmap.h"

#define LOGNAMESIZE (MAXLOGNAME-1)

static          char locked_str[] = "*LOCKED*";

static int      print_user(struct passwd * pwd, int pretty, int v7);
static uid_t    pw_uidpolicy(struct userconf * cnf, struct cargs * args);
static uid_t    pw_gidpolicy(struct userconf * cnf, struct cargs * args, char *nam, gid_t prefer);
static time_t   pw_pwdpolicy(struct userconf * cnf, struct cargs * args);
static time_t   pw_exppolicy(struct userconf * cnf, struct cargs * args);
static char    *pw_homepolicy(struct userconf * cnf, struct cargs * args, char const * user);
static char    *pw_shellpolicy(struct userconf * cnf, struct cargs * args, char *newshell);
static char    *pw_password(struct userconf * cnf, struct cargs * args, char const * user);
static char    *shell_path(char const * path, char *shells[], char *sh);
static void     rmat(uid_t uid);
static void     rmopie(char const * name);

/*-
 * -C config      configuration file
 * -q             quiet operation
 * -n name        login name
 * -u uid         user id
 * -c comment     user name/comment
 * -d directory   home directory
 * -e date        account expiry date
 * -p date        password expiry date
 * -g grp         primary group
 * -G grp1,grp2   additional groups
 * -m [ -k dir ]  create and set up home
 * -s shell       name of login shell
 * -o             duplicate uid ok
 * -L class       user class
 * -l name        new login name
 * -h fd          password filehandle
 * -H fd          encrypted password filehandle
 * -F             force print or add
 *   Setting defaults:
 * -D             set user defaults
 * -b dir         default home root dir
 * -e period      default expiry period
 * -p period      default password change period
 * -g group       default group
 * -G             grp1,grp2.. default additional groups
 * -L class       default login class
 * -k dir         default home skeleton
 * -s shell       default shell
 * -w method      default password method
 */

int
pw_user(struct userconf * cnf, int mode, struct cargs * args)
{
        int             rc, edited = 0;
        char           *p = NULL;
        char                                     *passtmp;
        struct carg    *a_name;
        struct carg    *a_uid;
        struct carg    *arg;
        struct passwd  *pwd = NULL;
        struct group   *grp;
        struct stat     st;
        char            line[_PASSWORD_LEN+1];
        FILE           *fp;
        char *dmode_c;
        void *set = NULL;

        static struct passwd fakeuser =
        {
                NULL,
                "*",
                -1,
                -1,
                0,
                "",
                "User &",
                "/nonexistent",
                "/bin/sh",
                0
#if defined(__FreeBSD__)
                ,0
#endif
        };


        /*
         * With M_NEXT, we only need to return the
         * next uid to stdout
         */
        if (mode == M_NEXT)
        {
                uid_t next = pw_uidpolicy(cnf, args);
                if (getarg(args, 'q'))
                        return next;
                printf("%ld:", (long)next);
                pw_group(cnf, mode, args);
                return EXIT_SUCCESS;
        }

        /*
         * We can do all of the common legwork here
         */

        if ((arg = getarg(args, 'b')) != NULL) {
                cnf->home = arg->val;
        }

        if ((arg = getarg(args, 'M')) != NULL) {
                dmode_c = arg->val;
                if ((set = setmode(dmode_c)) == NULL)
                        errx(EX_DATAERR, "invalid directory creation mode '%s'",
                            dmode_c);
                cnf->homemode = getmode(set, _DEF_DIRMODE);
                free(set);
        }

        /*
         * If we'll need to use it or we're updating it,
         * then create the base home directory if necessary
         */
        if (arg != NULL || getarg(args, 'm') != NULL) {
                int     l = strlen(cnf->home);

                if (l > 1 && cnf->home[l-1] == '/')     /* Shave off any trailing path delimiter */
                        cnf->home[--l] = '\0';

                if (l < 2 || *cnf->home != '/')         /* Check for absolute path name */
                        errx(EX_DATAERR, "invalid base directory for home '%s'", cnf->home);

                if (stat(cnf->home, &st) == -1) {
                        char    dbuf[MAXPATHLEN];

                        /*
                         * This is a kludge especially for Joerg :)
                         * If the home directory would be created in the root partition, then
                         * we really create it under /usr which is likely to have more space.
                         * But we create a symlink from cnf->home -> "/usr" -> cnf->home
                         */
                        if (strchr(cnf->home+1, '/') == NULL) {
                                strcpy(dbuf, "/usr");
                                strncat(dbuf, cnf->home, MAXPATHLEN-5);
                                if (mkdir(dbuf, _DEF_DIRMODE) != -1 || errno == EEXIST) {
                                        chown(dbuf, 0, 0);
                                        /*
                                         * Skip first "/" and create symlink:
                                         * /home -> usr/home
                                         */
                                        symlink(dbuf+1, cnf->home);
                                }
                                /* If this falls, fall back to old method */
                        }
                        strlcpy(dbuf, cnf->home, sizeof(dbuf));
                        p = dbuf;
                        if (stat(dbuf, &st) == -1) {
                                while ((p = strchr(++p, '/')) != NULL) {
                                        *p = '\0';
                                        if (stat(dbuf, &st) == -1) {
                                                if (mkdir(dbuf, _DEF_DIRMODE) == -1)
                                                        goto direrr;
                                                chown(dbuf, 0, 0);
                                        } else if (!S_ISDIR(st.st_mode))
                                                errx(EX_OSFILE, "'%s' (root home parent) is not a directory", dbuf);
                                        *p = '/';
                                }
                        }
                        if (stat(dbuf, &st) == -1) {
                                if (mkdir(dbuf, _DEF_DIRMODE) == -1) {
                                direrr: err(EX_OSFILE, "mkdir '%s'", dbuf);
                                }
                                chown(dbuf, 0, 0);
                        }
                } else if (!S_ISDIR(st.st_mode))
                        errx(EX_OSFILE, "root home `%s' is not a directory", cnf->home);
        }

        if ((arg = getarg(args, 'e')) != NULL)
                cnf->expire_days = atoi(arg->val);

        if ((arg = getarg(args, 'y')) != NULL)
                cnf->nispasswd = arg->val;

        if ((arg = getarg(args, 'p')) != NULL && arg->val)
                cnf->password_days = atoi(arg->val);

        if ((arg = getarg(args, 'g')) != NULL) {
                if (!*(p = arg->val))   /* Handle empty group list specially */
                        cnf->default_group = "";
                else {
                        if ((grp = GETGRNAM(p)) == NULL) {
                                if (!isdigit((unsigned char)*p) || (grp = GETGRGID((gid_t) atoi(p))) == NULL)
                                        errx(EX_NOUSER, "group `%s' does not exist", p);
                        }
                        cnf->default_group = newstr(grp->gr_name);
                }
        }
        if ((arg = getarg(args, 'L')) != NULL)
                cnf->default_class = pw_checkname((u_char *)arg->val, 0);

        if ((arg = getarg(args, 'G')) != NULL && arg->val) {
                int i = 0;

                for (p = strtok(arg->val, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
                        if ((grp = GETGRNAM(p)) == NULL) {
                                if (!isdigit((unsigned char)*p) || (grp = GETGRGID((gid_t) atoi(p))) == NULL)
                                        errx(EX_NOUSER, "group `%s' does not exist", p);
                        }
                        if (extendarray(&cnf->groups, &cnf->numgroups, i + 2) != -1)
                                cnf->groups[i++] = newstr(grp->gr_name);
                }
                while (i < cnf->numgroups)
                        cnf->groups[i++] = NULL;
        }

        if ((arg = getarg(args, 'k')) != NULL) {
                if (stat(cnf->dotdir = arg->val, &st) == -1 || !S_ISDIR(st.st_mode))
                        errx(EX_OSFILE, "skeleton `%s' is not a directory or does not exist", cnf->dotdir);
        }

        if ((arg = getarg(args, 's')) != NULL)
                cnf->shell_default = arg->val;

        if ((arg = getarg(args, 'w')) != NULL)
                cnf->default_password = boolean_val(arg->val, cnf->default_password);
        if (mode == M_ADD && getarg(args, 'D')) {
                if (getarg(args, 'n') != NULL)
                        errx(EX_DATAERR, "can't combine `-D' with `-n name'");
                if ((arg = getarg(args, 'u')) != NULL && (p = strtok(arg->val, ", \t")) != NULL) {
                        if ((cnf->min_uid = (uid_t) atoi(p)) == 0)
                                cnf->min_uid = 1000;
                        if ((p = strtok(NULL, " ,\t")) == NULL || (cnf->max_uid = (uid_t) atoi(p)) < cnf->min_uid)
                                cnf->max_uid = 32000;
                }
                if ((arg = getarg(args, 'i')) != NULL && (p = strtok(arg->val, ", \t")) != NULL) {
                        if ((cnf->min_gid = (gid_t) atoi(p)) == 0)
                                cnf->min_gid = 1000;
                        if ((p = strtok(NULL, " ,\t")) == NULL || (cnf->max_gid = (gid_t) atoi(p)) < cnf->min_gid)
                                cnf->max_gid = 32000;
                }

                arg = getarg(args, 'C');
                if (write_userconfig(arg ? arg->val : NULL))
                        return EXIT_SUCCESS;
                warn("config update");
                return EX_IOERR;
        }

        if (mode == M_PRINT && getarg(args, 'a')) {
                int             pretty = getarg(args, 'P') != NULL;
                int             v7 = getarg(args, '7') != NULL;
                SETPWENT();
                while ((pwd = GETPWENT()) != NULL)
                        print_user(pwd, pretty, v7);
                ENDPWENT();
                return EXIT_SUCCESS;
        }

        if ((a_name = getarg(args, 'n')) != NULL)
                pwd = GETPWNAM(pw_checkname((u_char *)a_name->val, 0));
        a_uid = getarg(args, 'u');

        if (a_uid == NULL) {
                if (a_name == NULL)
                        errx(EX_DATAERR, "user name or id required");

                /*
                 * Determine whether 'n' switch is name or uid - we don't
                 * really don't really care which we have, but we need to
                 * know.
                 */
                if (mode != M_ADD && pwd == NULL
                    && strspn(a_name->val, "0123456789") == strlen(a_name->val)
                    && *a_name->val) {
                        (a_uid = a_name)->ch = 'u';
                        a_name = NULL;
                }
        }

        /*
         * Update, delete & print require that the user exists
         */
        if (mode == M_UPDATE || mode == M_DELETE ||
            mode == M_PRINT  || mode == M_LOCK   || mode == M_UNLOCK) {

                if (a_name == NULL && pwd == NULL)      /* Try harder */
                        pwd = GETPWUID(atoi(a_uid->val));

                if (pwd == NULL) {
                        if (mode == M_PRINT && getarg(args, 'F')) {
                                fakeuser.pw_name = a_name ? a_name->val : "nouser";
                                fakeuser.pw_uid = a_uid ? (uid_t) atol(a_uid->val) : -1;
                                return print_user(&fakeuser,
                                                  getarg(args, 'P') != NULL,
                                                  getarg(args, '7') != NULL);
                        }
                        if (a_name == NULL)
                                errx(EX_NOUSER, "no such uid `%s'", a_uid->val);
                        errx(EX_NOUSER, "no such user `%s'", a_name->val);
                }

                if (a_name == NULL)     /* May be needed later */
                        a_name = addarg(args, 'n', newstr(pwd->pw_name));

                /*
                 * The M_LOCK and M_UNLOCK functions simply add or remove
                 * a "*LOCKED*" prefix from in front of the password to
                 * prevent it decoding correctly, and therefore prevents
                 * access. Of course, this only prevents access via
                 * password authentication (not ssh, kerberos or any
                 * other method that does not use the UNIX password) but
                 * that is a known limitation.
                 */

                if (mode == M_LOCK) {
                        if (strncmp(pwd->pw_passwd, locked_str, sizeof(locked_str)-1) == 0)
                                errx(EX_DATAERR, "user '%s' is already locked", pwd->pw_name);
                        passtmp = malloc(strlen(pwd->pw_passwd) + sizeof(locked_str));
                        if (passtmp == NULL)    /* disaster */
                                errx(EX_UNAVAILABLE, "out of memory");
                        strcpy(passtmp, locked_str);
                        strcat(passtmp, pwd->pw_passwd);
                        pwd->pw_passwd = passtmp;
                        edited = 1;
                } else if (mode == M_UNLOCK) {
                        if (strncmp(pwd->pw_passwd, locked_str, sizeof(locked_str)-1) != 0)
                                errx(EX_DATAERR, "user '%s' is not locked", pwd->pw_name);
                        pwd->pw_passwd += sizeof(locked_str)-1;
                        edited = 1;
                } else if (mode == M_DELETE) {
                        /*
                         * Handle deletions now
                         */
                        char            file[MAXPATHLEN];
                        char            home[MAXPATHLEN];
                        uid_t           uid = pwd->pw_uid;

                        if (strcmp(pwd->pw_name, "root") == 0)
                                errx(EX_DATAERR, "cannot remove user 'root'");

                        if (!PWALTDIR()) {
                                /*
                                 * Remove opie record from /etc/opiekeys
                                 */

                                rmopie(pwd->pw_name);

                                /*
                                 * Remove crontabs
                                 */
                                snprintf(file, sizeof(file), "/var/cron/tabs/%s", pwd->pw_name);
                                if (access(file, F_OK) == 0) {
                                        sprintf(file, "crontab -u %s -r", pwd->pw_name);
                                        system(file);
                                }
                        }
                        /*
                         * Save these for later, since contents of pwd may be
                         * invalidated by deletion
                         */
                        sprintf(file, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
                        strlcpy(home, pwd->pw_dir, sizeof(home));

                        rc = delpwent(pwd);
                        if (rc == -1)
                                err(EX_IOERR, "user '%s' does not exist", pwd->pw_name);
                        else if (rc != 0) {
                                warn("passwd update");
                                return EX_IOERR;
                        }

                        if (cnf->nispasswd && *cnf->nispasswd=='/') {
                                rc = delnispwent(cnf->nispasswd, a_name->val);
                                if (rc == -1)
                                        warnx("WARNING: user '%s' does not exist in NIS passwd", pwd->pw_name);
                                else if (rc != 0)
                                        warn("WARNING: NIS passwd update");
                                /* non-fatal */
                        }

                        grp = GETGRNAM(a_name->val);
                        if (grp != NULL && *grp->gr_mem == NULL)
                                delgrent(GETGRNAM(a_name->val));
                        SETGRENT();
                        while ((grp = GETGRENT()) != NULL) {
                                int i;
                                char group[MAXLOGNAME];
                                for (i = 0; grp->gr_mem[i] != NULL; i++) {
                                        if (!strcmp(grp->gr_mem[i], a_name->val)) {
                                                while (grp->gr_mem[i] != NULL) {
                                                        grp->gr_mem[i] = grp->gr_mem[i+1];
                                                }       
                                                strlcpy(group, grp->gr_name, MAXLOGNAME);
                                                chggrent(group, grp);
                                        }
                                }
                        }
                        ENDGRENT();

                        pw_log(cnf, mode, W_USER, "%s(%ld) account removed", a_name->val, (long) uid);

                        if (!PWALTDIR()) {
                                /*
                                 * Remove mail file
                                 */
                                remove(file);

                                /*
                                 * Remove at jobs
                                 */
                                if (getpwuid(uid) == NULL)
                                        rmat(uid);

                                /*
                                 * Remove home directory and contents
                                 */
                                if (getarg(args, 'r') != NULL && *home == '/' && getpwuid(uid) == NULL) {
                                        if (stat(home, &st) != -1) {
                                                rm_r(home, uid);
                                                pw_log(cnf, mode, W_USER, "%s(%ld) home '%s' %sremoved",
                                                       a_name->val, (long) uid, home,
                                                       stat(home, &st) == -1 ? "" : "not completely ");
                                        }
                                }
                        }
                        return EXIT_SUCCESS;
                } else if (mode == M_PRINT)
                        return print_user(pwd,
                                          getarg(args, 'P') != NULL,
                                          getarg(args, '7') != NULL);

                /*
                 * The rest is edit code
                 */
                if ((arg = getarg(args, 'l')) != NULL) {
                        if (strcmp(pwd->pw_name, "root") == 0)
                                errx(EX_DATAERR, "can't rename `root' account");
                        pwd->pw_name = pw_checkname((u_char *)arg->val, 0);
                        edited = 1;
                }

                if ((arg = getarg(args, 'u')) != NULL && isdigit((unsigned char)*arg->val)) {
                        pwd->pw_uid = (uid_t) atol(arg->val);
                        edited = 1;
                        if (pwd->pw_uid != 0 && strcmp(pwd->pw_name, "root") == 0)
                                errx(EX_DATAERR, "can't change uid of `root' account");
                        if (pwd->pw_uid == 0 && strcmp(pwd->pw_name, "root") != 0)
                                warnx("WARNING: account `%s' will have a uid of 0 (superuser access!)", pwd->pw_name);
                }

                if ((arg = getarg(args, 'g')) != NULL && pwd->pw_uid != 0) {    /* Already checked this */
                        gid_t newgid = (gid_t) GETGRNAM(cnf->default_group)->gr_gid;
                        if (newgid != pwd->pw_gid) {
                                edited = 1;
                                pwd->pw_gid = newgid;
                        }
                }

                if ((arg = getarg(args, 'p')) != NULL) {
                        if (*arg->val == '\0' || strcmp(arg->val, "0") == 0) {
                                if (pwd->pw_change != 0) {
                                        pwd->pw_change = 0;
                                        edited = 1;
                                }
                        }
                        else {
                                time_t          now = time(NULL);
                                time_t          expire = parse_date(now, arg->val);

                                if (now == expire)
                                        errx(EX_DATAERR, "invalid password change date `%s'", arg->val);
                                if (pwd->pw_change != expire) {
                                        pwd->pw_change = expire;
                                        edited = 1;
                                }
                        }
                }

                if ((arg = getarg(args, 'e')) != NULL) {
                        if (*arg->val == '\0' || strcmp(arg->val, "0") == 0) {
                                if (pwd->pw_expire != 0) {
                                        pwd->pw_expire = 0;
                                        edited = 1;
                                }
                        }
                        else {
                                time_t          now = time(NULL);
                                time_t          expire = parse_date(now, arg->val);

                                if (now == expire)
                                        errx(EX_DATAERR, "invalid account expiry date `%s'", arg->val);
                                if (pwd->pw_expire != expire) {
                                        pwd->pw_expire = expire;
                                        edited = 1;
                                }
                        }
                }

                if ((arg = getarg(args, 's')) != NULL) {
                        char *shell = shell_path(cnf->shelldir, cnf->shells, arg->val);
                        if (shell == NULL)
                                shell = "";
                        if (strcmp(shell, pwd->pw_shell) != 0) {
                                pwd->pw_shell = shell;
                                edited = 1;
                        }
                }

                if (getarg(args, 'L')) {
                        if (cnf->default_class == NULL)
                                cnf->default_class = "";
                        if (strcmp(pwd->pw_class, cnf->default_class) != 0) {
                                pwd->pw_class = cnf->default_class;
                                edited = 1;
                        }
                }

                if ((arg  = getarg(args, 'd')) != NULL) {
                        if (strcmp(pwd->pw_dir, arg->val))
                                edited = 1;
                        if (stat(pwd->pw_dir = arg->val, &st) == -1) {
                                if (getarg(args, 'm') == NULL && strcmp(pwd->pw_dir, "/nonexistent") != 0)
                                  warnx("WARNING: home `%s' does not exist", pwd->pw_dir);
                        } else if (!S_ISDIR(st.st_mode))
                                warnx("WARNING: home `%s' is not a directory", pwd->pw_dir);
                }

                if ((arg = getarg(args, 'w')) != NULL &&
                    getarg(args, 'h') == NULL && getarg(args, 'H') == NULL) {
                        login_cap_t *lc;

                        lc = login_getpwclass(pwd);
                        if (lc == NULL ||
                            login_setcryptfmt(lc, "md5", NULL) == NULL)
                                warn("setting crypt(3) format");
                        login_close(lc);
                        pwd->pw_passwd = pw_password(cnf, args, pwd->pw_name);
                        edited = 1;
                }

        } else {
                login_cap_t *lc;

                /*
                 * Add code
                 */

                if (a_name == NULL)     /* Required */
                        errx(EX_DATAERR, "login name required");
                else if ((pwd = GETPWNAM(a_name->val)) != NULL) /* Exists */
                        errx(EX_DATAERR, "login name `%s' already exists", a_name->val);

                /*
                 * Now, set up defaults for a new user
                 */
                pwd = &fakeuser;
                pwd->pw_name = a_name->val;
                pwd->pw_class = cnf->default_class ? cnf->default_class : "";
                pwd->pw_uid = pw_uidpolicy(cnf, args);
                pwd->pw_gid = pw_gidpolicy(cnf, args, pwd->pw_name, (gid_t) pwd->pw_uid);
                pwd->pw_change = pw_pwdpolicy(cnf, args);
                pwd->pw_expire = pw_exppolicy(cnf, args);
                pwd->pw_dir = pw_homepolicy(cnf, args, pwd->pw_name);
                pwd->pw_shell = pw_shellpolicy(cnf, args, NULL);
                lc = login_getpwclass(pwd);
                if (lc == NULL || login_setcryptfmt(lc, "md5", NULL) == NULL)
                        warn("setting crypt(3) format");
                login_close(lc);
                pwd->pw_passwd = pw_password(cnf, args, pwd->pw_name);
                edited = 1;

                if (pwd->pw_uid == 0 && strcmp(pwd->pw_name, "root") != 0)
                        warnx("WARNING: new account `%s' has a uid of 0 (superuser access!)", pwd->pw_name);
        }

        /*
         * Shared add/edit code
         */
        if ((arg = getarg(args, 'c')) != NULL) {
                char    *gecos = pw_checkname((u_char *)arg->val, 1);
                if (strcmp(pwd->pw_gecos, gecos) != 0) {
                        pwd->pw_gecos = gecos;
                        edited = 1;
                }
        }

        if ((arg = getarg(args, 'h')) != NULL ||
            (arg = getarg(args, 'H')) != NULL) {
                if (strcmp(arg->val, "-") == 0) {
                        if (!pwd->pw_passwd || *pwd->pw_passwd != '*') {
                                pwd->pw_passwd = "*";   /* No access */
                                edited = 1;
                        }
                } else {
                        int             fd = atoi(arg->val);
                        int             precrypt = (arg->ch == 'H');
                        int             b;
                        int             istty = isatty(fd);
                        struct termios  t;
                        login_cap_t     *lc;

                        if (istty) {
                                if (tcgetattr(fd, &t) == -1)
                                        istty = 0;
                                else {
                                        struct termios  n = t;

                                        /* Disable echo */
                                        n.c_lflag &= ~(ECHO);
                                        tcsetattr(fd, TCSANOW, &n);
                                        printf("%s%spassword for user %s:",
                                             (mode == M_UPDATE) ? "new " : "",
                                             precrypt ? "encrypted " : "",
                                             pwd->pw_name);
                                        fflush(stdout);
                                }
                        }
                        b = read(fd, line, sizeof(line) - 1);
                        if (istty) {    /* Restore state */
                                tcsetattr(fd, TCSANOW, &t);
                                fputc('\n', stdout);
                                fflush(stdout);
                        }
                        if (b < 0) {
                                warn("-%c file descriptor", precrypt ? 'H' :
                                    'h');
                                return EX_IOERR;
                        }
                        line[b] = '\0';
                        if ((p = strpbrk(line, "\r\n")) != NULL)
                                *p = '\0';
                        if (!*line)
                                errx(EX_DATAERR, "empty password read on file descriptor %d", fd);
                        if (precrypt) {
                                if (strchr(line, ':') != NULL)
                                        return EX_DATAERR;
                                pwd->pw_passwd = line;
                        } else {
                                lc = login_getpwclass(pwd);
                                if (lc == NULL ||
                                    login_setcryptfmt(lc, "md5", NULL) == NULL)
                                        warn("setting crypt(3) format");
                                login_close(lc);
                                pwd->pw_passwd = pw_pwcrypt(line);
                        }
                        edited = 1;
                }
        }

        /*
         * Special case: -N only displays & exits
         */
        if (getarg(args, 'N') != NULL)
                return print_user(pwd,
                                  getarg(args, 'P') != NULL,
                                  getarg(args, '7') != NULL);

        if (mode == M_ADD) {
                edited = 1;     /* Always */
                rc = addpwent(pwd);
                if (rc == -1) {
                        warnx("user '%s' already exists", pwd->pw_name);
                        return EX_IOERR;
                } else if (rc != 0) {
                        warn("passwd file update");
                        return EX_IOERR;
                }
                if (cnf->nispasswd && *cnf->nispasswd=='/') {
                        rc = addnispwent(cnf->nispasswd, pwd);
                        if (rc == -1)
                                warnx("User '%s' already exists in NIS passwd", pwd->pw_name);
                        else
                                warn("NIS passwd update");
                        /* NOTE: we treat NIS-only update errors as non-fatal */
                }
        } else if (mode == M_UPDATE || mode == M_LOCK || mode == M_UNLOCK) {
                if (edited) {   /* Only updated this if required */
                        rc = chgpwent(a_name->val, pwd);
                        if (rc == -1) {
                                warnx("user '%s' does not exist (NIS?)", pwd->pw_name);
                                return EX_IOERR;
                        } else if (rc != 0) {
                                warn("passwd file update");
                                return EX_IOERR;
                        }
                        if ( cnf->nispasswd && *cnf->nispasswd=='/') {
                                rc = chgnispwent(cnf->nispasswd, a_name->val, pwd);
                                if (rc == -1)
                                        warn("User '%s' not found in NIS passwd", pwd->pw_name);
                                else
                                        warn("NIS passwd update");
                                /* NOTE: NIS-only update errors are not fatal */
                        }
                }
        }

        /*
         * Ok, user is created or changed - now edit group file
         */

        if (mode == M_ADD || getarg(args, 'G') != NULL) {
                int i;
                for (i = 0; cnf->groups[i] != NULL; i++) {
                        grp = GETGRNAM(cnf->groups[i]);
                        grp = gr_add(grp, pwd->pw_name);
                        /*
                         * grp can only be NULL in 2 cases:
                         * - the new member is already a member
                         * - a problem with memory occurs
                         * in both cases we want to skip now.
                         */
                        if (grp == NULL)
                                continue;
                        chggrent(cnf->groups[i], grp);
                        free(grp);
                }
        }


        /* go get a current version of pwd */
        pwd = GETPWNAM(a_name->val);
        if (pwd == NULL) {
                /* This will fail when we rename, so special case that */
                if (mode == M_UPDATE && (arg = getarg(args, 'l')) != NULL) {
                        a_name->val = arg->val;         /* update new name */
                        pwd = GETPWNAM(a_name->val);    /* refetch renamed rec */
                }
        }
        if (pwd == NULL)        /* can't go on without this */
                errx(EX_NOUSER, "user '%s' disappeared during update", a_name->val);

        grp = GETGRGID(pwd->pw_gid);
        pw_log(cnf, mode, W_USER, "%s(%ld):%s(%ld):%s:%s:%s",
               pwd->pw_name, (long) pwd->pw_uid,
            grp ? grp->gr_name : "unknown", (long) (grp ? grp->gr_gid : -1),
               pwd->pw_gecos, pwd->pw_dir, pwd->pw_shell);

        /*
         * If adding, let's touch and chown the user's mail file. This is not
         * strictly necessary under BSD with a 0755 maildir but it also
         * doesn't hurt anything to create the empty mailfile
         */
        if (mode == M_ADD) {
                if (!PWALTDIR()) {
                        sprintf(line, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
                        close(open(line, O_RDWR | O_CREAT, 0600));      /* Preserve contents &
                                                                         * mtime */
                        chown(line, pwd->pw_uid, pwd->pw_gid);
                }
        }

        /*
         * Let's create and populate the user's home directory. Note
         * that this also `works' for editing users if -m is used, but
         * existing files will *not* be overwritten.
         */
        if (!PWALTDIR() && getarg(args, 'm') != NULL && pwd->pw_dir && *pwd->pw_dir == '/' && pwd->pw_dir[1]) {
                copymkdir(pwd->pw_dir, cnf->dotdir, cnf->homemode, pwd->pw_uid, pwd->pw_gid);
                pw_log(cnf, mode, W_USER, "%s(%ld) home %s made",
                       pwd->pw_name, (long) pwd->pw_uid, pwd->pw_dir);
        }


        /*
         * Finally, send mail to the new user as well, if we are asked to
         */
        if (mode == M_ADD && !PWALTDIR() && cnf->newmail && *cnf->newmail && (fp = fopen(cnf->newmail, "r")) != NULL) {
                FILE           *pfp = popen(_PATH_SENDMAIL " -t", "w");
                
                if (pfp == NULL)
                        warn("sendmail");
                else {
                        fprintf(pfp, "From: root\n" "To: %s\n" "Subject: Welcome!\n\n", pwd->pw_name);
                        while (fgets(line, sizeof(line), fp) != NULL) {
                                /* Do substitutions? */
                                fputs(line, pfp);
                        }
                        pclose(pfp);
                        pw_log(cnf, mode, W_USER, "%s(%ld) new user mail sent",
                            pwd->pw_name, (long) pwd->pw_uid);
                }
                fclose(fp);
        }

        return EXIT_SUCCESS;
}


static          uid_t
pw_uidpolicy(struct userconf * cnf, struct cargs * args)
{
        struct passwd  *pwd;
        uid_t           uid = (uid_t) - 1;
        struct carg    *a_uid = getarg(args, 'u');

        /*
         * Check the given uid, if any
         */
        if (a_uid != NULL) {
                uid = (uid_t) atol(a_uid->val);

                if ((pwd = GETPWUID(uid)) != NULL && getarg(args, 'o') == NULL)
                        errx(EX_DATAERR, "uid `%ld' has already been allocated", (long) pwd->pw_uid);
        } else {
                struct bitmap   bm;

                /*
                 * We need to allocate the next available uid under one of
                 * two policies a) Grab the first unused uid b) Grab the
                 * highest possible unused uid
                 */
                if (cnf->min_uid >= cnf->max_uid) {     /* Sanity
                                                         * claus^H^H^H^Hheck */
                        cnf->min_uid = 1000;
                        cnf->max_uid = 32000;
                }
                bm = bm_alloc(cnf->max_uid - cnf->min_uid + 1);

                /*
                 * Now, let's fill the bitmap from the password file
                 */
                SETPWENT();
                while ((pwd = GETPWENT()) != NULL)
                        if (pwd->pw_uid >= (uid_t) cnf->min_uid && pwd->pw_uid <= (uid_t) cnf->max_uid)
                                bm_setbit(&bm, pwd->pw_uid - cnf->min_uid);
                ENDPWENT();

                /*
                 * Then apply the policy, with fallback to reuse if necessary
                 */
                if (cnf->reuse_uids || (uid = (uid_t) (bm_lastset(&bm) + cnf->min_uid + 1)) > cnf->max_uid)
                        uid = (uid_t) (bm_firstunset(&bm) + cnf->min_uid);

                /*
                 * Another sanity check
                 */
                if (uid < cnf->min_uid || uid > cnf->max_uid)
                        errx(EX_SOFTWARE, "unable to allocate a new uid - range fully used");
                bm_dealloc(&bm);
        }
        return uid;
}


static          uid_t
pw_gidpolicy(struct userconf * cnf, struct cargs * args, char *nam, gid_t prefer)
{
        struct group   *grp;
        gid_t           gid = (uid_t) - 1;
        struct carg    *a_gid = getarg(args, 'g');

        /*
         * If no arg given, see if default can help out
         */
        if (a_gid == NULL && cnf->default_group && *cnf->default_group)
                a_gid = addarg(args, 'g', cnf->default_group);

        /*
         * Check the given gid, if any
         */
        SETGRENT();
        if (a_gid != NULL) {
                if ((grp = GETGRNAM(a_gid->val)) == NULL) {
                        gid = (gid_t) atol(a_gid->val);
                        if ((gid == 0 && !isdigit((unsigned char)*a_gid->val)) || (grp = GETGRGID(gid)) == NULL)
                                errx(EX_NOUSER, "group `%s' is not defined", a_gid->val);
                }
                gid = grp->gr_gid;
        } else if ((grp = GETGRNAM(nam)) != NULL && grp->gr_mem[0] == NULL) {
                gid = grp->gr_gid;  /* Already created? Use it anyway... */
        } else {
                struct cargs    grpargs;
                char            tmp[32];

                LIST_INIT(&grpargs);
                addarg(&grpargs, 'n', nam);

                /*
                 * We need to auto-create a group with the user's name. We
                 * can send all the appropriate output to our sister routine
                 * bit first see if we can create a group with gid==uid so we
                 * can keep the user and group ids in sync. We purposely do
                 * NOT check the gid range if we can force the sync. If the
                 * user's name dups an existing group, then the group add
                 * function will happily handle that case for us and exit.
                 */
                if (GETGRGID(prefer) == NULL) {
                        sprintf(tmp, "%lu", (unsigned long) prefer);
                        addarg(&grpargs, 'g', tmp);
                }
                if (getarg(args, 'N'))
                {
                        addarg(&grpargs, 'N', NULL);
                        addarg(&grpargs, 'q', NULL);
                        gid = pw_group(cnf, M_NEXT, &grpargs);
                }
                else
                {
                        pw_group(cnf, M_ADD, &grpargs);
                        if ((grp = GETGRNAM(nam)) != NULL)
                                gid = grp->gr_gid;
                }
                a_gid = LIST_FIRST(&grpargs);
                while (a_gid != NULL) {
                        struct carg    *t = LIST_NEXT(a_gid, list);
                        LIST_REMOVE(a_gid, list);
                        a_gid = t;
                }
        }
        ENDGRENT();
        return gid;
}


static          time_t
pw_pwdpolicy(struct userconf * cnf, struct cargs * args)
{
        time_t          result = 0;
        time_t          now = time(NULL);
        struct carg    *arg = getarg(args, 'p');

        if (arg != NULL) {
                if ((result = parse_date(now, arg->val)) == now)
                        errx(EX_DATAERR, "invalid date/time `%s'", arg->val);
        } else if (cnf->password_days > 0)
                result = now + ((long) cnf->password_days * 86400L);
        return result;
}


static          time_t
pw_exppolicy(struct userconf * cnf, struct cargs * args)
{
        time_t          result = 0;
        time_t          now = time(NULL);
        struct carg    *arg = getarg(args, 'e');

        if (arg != NULL) {
                if ((result = parse_date(now, arg->val)) == now)
                        errx(EX_DATAERR, "invalid date/time `%s'", arg->val);
        } else if (cnf->expire_days > 0)
                result = now + ((long) cnf->expire_days * 86400L);
        return result;
}


static char    *
pw_homepolicy(struct userconf * cnf, struct cargs * args, char const * user)
{
        struct carg    *arg = getarg(args, 'd');

        if (arg)
                return arg->val;
        else {
                static char     home[128];

                if (cnf->home == NULL || *cnf->home == '\0')
                        errx(EX_CONFIG, "no base home directory set");
                sprintf(home, "%s/%s", cnf->home, user);
                return home;
        }
}

static char    *
shell_path(char const * path, char *shells[], char *sh)
{
        if (sh != NULL && (*sh == '/' || *sh == '\0'))
                return sh;      /* specified full path or forced none */
        else {
                char           *p;
                char            paths[_UC_MAXLINE];

                /*
                 * We need to search paths
                 */
                strlcpy(paths, path, sizeof(paths));
                for (p = strtok(paths, ": \t\r\n"); p != NULL; p = strtok(NULL, ": \t\r\n")) {
                        int             i;
                        static char     shellpath[256];

                        if (sh != NULL) {
                                sprintf(shellpath, "%s/%s", p, sh);
                                if (access(shellpath, X_OK) == 0)
                                        return shellpath;
                        } else
                                for (i = 0; i < _UC_MAXSHELLS && shells[i] != NULL; i++) {
                                        sprintf(shellpath, "%s/%s", p, shells[i]);
                                        if (access(shellpath, X_OK) == 0)
                                                return shellpath;
                                }
                }
                if (sh == NULL)
                        errx(EX_OSFILE, "can't find shell `%s' in shell paths", sh);
                errx(EX_CONFIG, "no default shell available or defined");
                return NULL;
        }
}


static char    *
pw_shellpolicy(struct userconf * cnf, struct cargs * args, char *newshell)
{
        char           *sh = newshell;
        struct carg    *arg = getarg(args, 's');

        if (newshell == NULL && arg != NULL)
                sh = arg->val;
        return shell_path(cnf->shelldir, cnf->shells, sh ? sh : cnf->shell_default);
}

#define SALTSIZE        32

static char const chars[] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ./";

char           *
pw_pwcrypt(char *password)
{
        int             i;
        char            salt[SALTSIZE + 1];
        char            *cryptpw;

        static char     buf[256];

        /*
         * Calculate a salt value
         */
        for (i = 0; i < SALTSIZE; i++)
                salt[i] = chars[arc4random_uniform(sizeof(chars) - 1)];
        salt[SALTSIZE] = '\0';

        cryptpw = crypt(password, salt);
        if (cryptpw == NULL)
                errx(EX_CONFIG, "crypt(3) failure");
        return strcpy(buf, cryptpw);
}


static char    *
pw_password(struct userconf * cnf, struct cargs * args, char const * user)
{
        int             i, l;
        char            pwbuf[32];

        switch (cnf->default_password) {
        case -1:                /* Random password */
                l = (arc4random() % 8 + 8);     /* 8 - 16 chars */
                for (i = 0; i < l; i++)
                        pwbuf[i] = chars[arc4random_uniform(sizeof(chars)-1)];
                pwbuf[i] = '\0';

                /*
                 * We give this information back to the user
                 */
                if (getarg(args, 'h') == NULL && getarg(args, 'H') == NULL &&
                    getarg(args, 'N') == NULL) {
                        if (isatty(STDOUT_FILENO))
                                printf("Password for '%s' is: ", user);
                        printf("%s\n", pwbuf);
                        fflush(stdout);
                }
                break;

        case -2:                /* No password at all! */
                return "";

        case 0:         /* No login - default */
        default:
                return "*";

        case 1:         /* user's name */
                strlcpy(pwbuf, user, sizeof(pwbuf));
                break;
        }
        return pw_pwcrypt(pwbuf);
}


static int
print_user(struct passwd * pwd, int pretty, int v7)
{
        if (!pretty) {
                char            *buf;

                if (!v7)
                        pwd->pw_passwd = (pwd->pw_passwd == NULL) ? "" : "*";

                buf = v7 ? pw_make_v7(pwd) : pw_make(pwd);
                printf("%s\n", buf);
                free(buf);
        } else {
                int             j;
                char           *p;
                struct group   *grp = GETGRGID(pwd->pw_gid);
                char            uname[60] = "User &", office[60] = "[None]",
                                wphone[60] = "[None]", hphone[60] = "[None]";
                char            acexpire[32] = "[None]", pwexpire[32] = "[None]";
                struct tm *    tptr;

                if ((p = strtok(pwd->pw_gecos, ",")) != NULL) {
                        strlcpy(uname, p, sizeof(uname));
                        if ((p = strtok(NULL, ",")) != NULL) {
                                strlcpy(office, p, sizeof(office));
                                if ((p = strtok(NULL, ",")) != NULL) {
                                        strlcpy(wphone, p, sizeof(wphone));
                                        if ((p = strtok(NULL, "")) != NULL) {
                                                strlcpy(hphone, p,
                                                    sizeof(hphone));
                                        }
                                }
                        }
                }
                /*
                 * Handle '&' in gecos field
                 */
                if ((p = strchr(uname, '&')) != NULL) {
                        int             l = strlen(pwd->pw_name);
                        int             m = strlen(p);

                        memmove(p + l, p + 1, m);
                        memmove(p, pwd->pw_name, l);
                        *p = (char) toupper((unsigned char)*p);
                }
                if (pwd->pw_expire > (time_t)0 && (tptr = localtime(&pwd->pw_expire)) != NULL)
                        strftime(acexpire, sizeof acexpire, "%c", tptr);
                if (pwd->pw_change > (time_t)0 && (tptr = localtime(&pwd->pw_change)) != NULL)
                        strftime(pwexpire, sizeof pwexpire, "%c", tptr);
                printf("Login Name: %-15s   #%-12ld Group: %-15s   #%ld\n"
                       " Full Name: %s\n"
                       "      Home: %-26.26s      Class: %s\n"
                       "     Shell: %-26.26s     Office: %s\n"
                       "Work Phone: %-26.26s Home Phone: %s\n"
                       "Acc Expire: %-26.26s Pwd Expire: %s\n",
                       pwd->pw_name, (long) pwd->pw_uid,
                       grp ? grp->gr_name : "(invalid)", (long) pwd->pw_gid,
                       uname, pwd->pw_dir, pwd->pw_class,
                       pwd->pw_shell, office, wphone, hphone,
                       acexpire, pwexpire);
                SETGRENT();
                j = 0;
                while ((grp=GETGRENT()) != NULL)
                {
                        int     i = 0;
                        while (grp->gr_mem[i] != NULL)
                        {
                                if (strcmp(grp->gr_mem[i], pwd->pw_name)==0)
                                {
                                        printf(j++ == 0 ? "    Groups: %s" : ",%s", grp->gr_name);
                                        break;
                                }
                                ++i;
                        }
                }
                ENDGRENT();
                printf("%s", j ? "\n" : "");
        }
        return EXIT_SUCCESS;
}

char    *
pw_checkname(u_char *name, int gecos)
{
        char showch[8];
        u_char const *badchars, *ch, *showtype;
        int reject;

        ch = name;
        reject = 0;
        if (gecos) {
                /* See if the name is valid as a gecos (comment) field. */
                badchars = ":!@";
                showtype = "gecos field";
        } else {
                /* See if the name is valid as a userid or group. */
                badchars = " ,\t:+&#%$^()!@~*?<>=|\\/\"";
                showtype = "userid/group name";
                /* Userids and groups can not have a leading '-'. */
                if (*ch == '-')
                        reject = 1;
        }
        if (!reject) {
                while (*ch) {
                        if (strchr(badchars, *ch) != NULL || *ch < ' ' ||
                            *ch == 127) {
                                reject = 1;
                                break;
                        }
                        /* 8-bit characters are only allowed in GECOS fields */
                        if (!gecos && (*ch & 0x80)) {
                                reject = 1;
                                break;
                        }
                        ch++;
                }
        }
        /*
         * A `$' is allowed as the final character for userids and groups,
         * mainly for the benefit of samba.
         */
        if (reject && !gecos) {
                if (*ch == '$' && *(ch + 1) == '\0') {
                        reject = 0;
                        ch++;
                }
        }
        if (reject) {
                snprintf(showch, sizeof(showch), (*ch >= ' ' && *ch < 127)
                    ? "`%c'" : "0x%02x", *ch);
                errx(EX_DATAERR, "invalid character %s at position %td in %s",
                    showch, (ch - name), showtype);
        }
        if (!gecos && (ch - name) > LOGNAMESIZE)
                errx(EX_DATAERR, "name too long `%s' (max is %d)", name,
                    LOGNAMESIZE);
        return (char *)name;
}


static void
rmat(uid_t uid)
{
        DIR            *d = opendir("/var/at/jobs");

        if (d != NULL) {
                struct dirent  *e;

                while ((e = readdir(d)) != NULL) {
                        struct stat     st;

                        if (strncmp(e->d_name, ".lock", 5) != 0 &&
                            stat(e->d_name, &st) == 0 &&
                            !S_ISDIR(st.st_mode) &&
                            st.st_uid == uid) {
                                char            tmp[MAXPATHLEN];

                                sprintf(tmp, "/usr/bin/atrm %s", e->d_name);
                                system(tmp);
                        }
                }
                closedir(d);
        }
}

static void
rmopie(char const * name)
{
        static const char etcopie[] = "/etc/opiekeys";
        FILE   *fp = fopen(etcopie, "r+");

        if (fp != NULL) {
                char    tmp[1024];
                off_t   atofs = 0;
                int     length = strlen(name);

                while (fgets(tmp, sizeof tmp, fp) != NULL) {
                        if (strncmp(name, tmp, length) == 0 && tmp[length]==' ') {
                                if (fseek(fp, atofs, SEEK_SET) == 0) {
                                        fwrite("#", 1, 1, fp);  /* Comment username out */
                                }
                                break;
                        }
                        atofs = ftell(fp);
                }
                /*
                 * If we got an error of any sort, don't update!
                 */
                fclose(fp);
        }
}