/*      $OpenBSD: pwd_mkdb.c,v 1.62 2024/07/28 19:13:26 millert Exp $   */

/*-
 * Copyright (c) 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Portions Copyright (c) 1994, Jason Downs.  All rights reserved.
 * Portions Copyright (c) 1998, Todd C. Miller.  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.
 * 3. 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/types.h>
#include <sys/stat.h>

#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

#define MINIMUM(a, b)   (((a) < (b)) ? (a) : (b))
#define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))
#define _MAXBSIZE       (64 * 1024)

#define INSECURE        1
#define SECURE          2
#define PERM_INSECURE   (S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)
#define PERM_SECURE     (S_IRUSR|S_IWUSR)

#define FILE_SECURE     0x01
#define FILE_INSECURE   0x02
#define FILE_ORIG       0x04

#define SHADOW_GROUP    "_shadow"

HASHINFO openinfo = {
        4096,           /* bsize */
        32,             /* ffactor */
        256,            /* nelem */
        2048 * 1024,    /* cachesize */
        NULL,           /* hash() */
        0               /* lorder */
};

static char *pname;                             /* password file name */
static char *basedir;                           /* dir holding master.passwd */
static int clean;                               /* what to remove on cleanup */
static int hasyp;                               /* are we running YP? */

void            cleanup(void);
__dead void     fatal(const char *, ...)
                    __attribute__((__format__ (printf, 1, 2)));
__dead void     fatalc(int, const char *, ...)
                    __attribute__((__format__ (printf, 2, 3)));
__dead void     fatalx(const char *, ...)
                    __attribute__((__format__ (printf, 1, 2)));
int             write_old_entry(FILE *, const struct passwd *);

void            cp(char *, char *, mode_t);
void            mv(char *, char *);
int             scan(FILE *, struct passwd *, int *);
void            usage(void);
char            *changedir(char *path, char *dir);
void            db_store(FILE *, FILE *, DB *, DB *,struct passwd *, int, char *, uid_t);

int
main(int argc, char **argv)
{
        DB *dp, *edp;
        DBT data, key;
        FILE *fp, *oldfp = NULL;
        struct stat st;
        struct passwd pwd;
        struct group *grp;
        sigset_t set;
        uid_t olduid;
        gid_t shadow;
        int ch, tfd, makeold, secureonly, flags, checkonly;
        char *username, buf[MAXIMUM(PATH_MAX, LINE_MAX * 2)];

        flags = checkonly = makeold = secureonly = 0;
        username = NULL;
        while ((ch = getopt(argc, argv, "cd:psu:v")) != -1)
                switch (ch) {
                case 'c':                       /* verify only */
                        checkonly = 1;
                        break;
                case 'd':
                        basedir = optarg;
                        if (strlen(basedir) > PATH_MAX - 40)
                                errx(1, "basedir too long");
                        break;
                case 'p':                       /* create V7 "file.orig" */
                        makeold = 1;
                        break;
                case 's':                       /* only update spwd.db */
                        secureonly = 1;
                        break;
                case 'u':                       /* only update this record */
                        username = optarg;
                        if (strlen(username) > _PW_NAME_LEN)
                                errx(1, "username too long");
                        break;
                case 'v':                       /* backward compatible */
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc != 1 || (makeold && secureonly) ||
            (username && (*username == '+' || *username == '-')))
                usage();

        if ((grp = getgrnam(SHADOW_GROUP)) == NULL)
                errx(1, "cannot find `%s' in the group database, aborting",
                    SHADOW_GROUP);
        shadow = grp->gr_gid;

        /*
         * This could be changed to allow the user to interrupt.
         * Probably not worth the effort.
         */
        sigemptyset(&set);
        sigaddset(&set, SIGTSTP);
        sigaddset(&set, SIGHUP);
        sigaddset(&set, SIGINT);
        sigaddset(&set, SIGQUIT);
        sigaddset(&set, SIGTERM);
        (void)sigprocmask(SIG_BLOCK, &set, (sigset_t *)NULL);

        /* We don't care what the user wants. */
        (void)umask(0);

        if (**argv != '/' && basedir == NULL)
                errx(1, "%s must be specified as an absolute path", *argv);

        if ((pname = strdup(changedir(*argv, basedir))) == NULL)
                err(1, NULL);
        /* Open the original password file */
        if (!(fp = fopen(pname, "r")))
                fatal("%s", pname);

        /* Check only if password database is valid */
        if (checkonly) {
                u_int cnt;

                for (cnt = 1; scan(fp, &pwd, &flags); ++cnt)
                        ;
                exit(0);
        }

        if (fstat(fileno(fp), &st) == -1)
                fatal("%s", pname);

        /* Tweak openinfo values for large passwd files. */
        if (st.st_size > (off_t)100*1024)
                openinfo.cachesize = MINIMUM(st.st_size * 20, (off_t)12*1024*1024);
        /* Estimate number of elements based on a 128-byte average entry. */
        if (st.st_size / 128 * 3 > openinfo.nelem)
                openinfo.nelem = st.st_size / 128 * 3;

        /* If only updating a single record, stash the old uid */
        if (username) {
                dp = dbopen(_PATH_MP_DB, O_RDONLY, 0, DB_HASH, NULL);
                if (dp == NULL)
                        fatal(_PATH_MP_DB);
                buf[0] = _PW_KEYBYNAME;
                strlcpy(buf + 1, username, sizeof(buf) - 1);
                key.data = (u_char *)buf;
                key.size = strlen(buf + 1) + 1;
                if ((dp->get)(dp, &key, &data, 0) == 0) {
                        char *p = (char *)data.data;
                        /* Skip to uid field */
                        while (*p++ != '\0')
                                ;
                        while (*p++ != '\0')
                                ;
                        memcpy(&olduid, p, sizeof(olduid));
                } else
                        olduid = -1;
                (dp->close)(dp);
        }

        /* Open the temporary encrypted password database. */
        (void)snprintf(buf, sizeof(buf), "%s.tmp",
            changedir(_PATH_SMP_DB, basedir));
        if (username) {
                cp(changedir(_PATH_SMP_DB, basedir), buf, PERM_SECURE);
                edp = dbopen(buf,
                    O_RDWR, PERM_SECURE, DB_HASH, &openinfo);
        } else {
                edp = dbopen(buf,
                    O_RDWR|O_CREAT|O_EXCL, PERM_SECURE, DB_HASH, &openinfo);
        }
        if (!edp)
                fatal("%s", buf);
        if (fchown(edp->fd(edp), -1, shadow) != 0)
                warn("%s: unable to set group to %s", _PATH_SMP_DB,
                    SHADOW_GROUP);
        else if (fchmod(edp->fd(edp), PERM_SECURE|S_IRGRP) != 0)
                warn("%s: unable to make group readable", _PATH_SMP_DB);
        clean |= FILE_SECURE;

        if (pledge("stdio rpath wpath cpath getpw fattr flock", NULL) == -1)
                err(1, "pledge");

        /* Open the temporary insecure password database. */
        if (!secureonly) {
                (void)snprintf(buf, sizeof(buf), "%s.tmp",
                    changedir(_PATH_MP_DB, basedir));
                if (username) {
                        cp(changedir(_PATH_MP_DB, basedir), buf, PERM_INSECURE);
                        dp = dbopen(buf, O_RDWR, PERM_INSECURE, DB_HASH,
                            &openinfo);
                } else {
                        dp = dbopen(buf, O_RDWR|O_CREAT|O_EXCL, PERM_INSECURE,
                            DB_HASH, &openinfo);
                }
                if (dp == NULL)
                        fatal("%s", buf);
                clean |= FILE_INSECURE;
        } else
                dp = NULL;

        /*
         * Open file for old password file.  Minor trickiness -- don't want to
         * change the file already existing, since someone (stupidly) might
         * still be using this for permission checking.  So, open it first and
         * fdopen the resulting fd.  The resulting file should be readable by
         * everyone.
         */
        if (makeold) {
                (void)snprintf(buf, sizeof(buf), "%s.orig", pname);
                if ((tfd = open(buf,
                    O_WRONLY|O_CREAT|O_EXCL, PERM_INSECURE)) == -1)
                        fatal("%s", buf);
                if ((oldfp = fdopen(tfd, "w")) == NULL)
                        fatal("%s", buf);
                clean |= FILE_ORIG;
        }

        /*
         * The databases actually contain three copies of the original data.
         * Each password file entry is converted into a rough approximation
         * of a ``struct passwd'', with the strings placed inline.  This
         * object is then stored as the data for three separate keys.  The
         * first key * is the pw_name field prepended by the _PW_KEYBYNAME
         * character.  The second key is the pw_uid field prepended by the
         * _PW_KEYBYUID character.  The third key is the line number in the
         * original file prepended by the _PW_KEYBYNUM character.  (The special
         * characters are prepended to ensure that the keys do not collide.)
         *
         * If we see something go by that looks like YP, we save a special
         * pointer record, which if YP is enabled in the C lib, will speed
         * things up.
         */

        /*
         * Write the .db files.
         * We do this three times, one per key type (for getpw{nam,uid,ent}).
         * The first time through we also check for YP, issue warnings
         * and save the V7 format passwd file if necessary.
         */
        db_store(fp, oldfp, edp, dp, &pwd, _PW_KEYBYNAME, username, olduid);
        db_store(fp, oldfp, edp, dp, &pwd, _PW_KEYBYUID, username, olduid);
        db_store(fp, oldfp, edp, dp, &pwd, _PW_KEYBYNUM, username, olduid);

        /* Store YP token, if needed. */
        if (hasyp && !username) {
                key.data = (u_char *)_PW_YPTOKEN;
                key.size = strlen(_PW_YPTOKEN);
                data.data = (u_char *)NULL;
                data.size = 0;

                if ((edp->put)(edp, &key, &data, R_NOOVERWRITE) == -1)
                        fatal("put");

                if (dp && (dp->put)(dp, &key, &data, R_NOOVERWRITE) == -1)
                        fatal("put");
        }

        if ((edp->close)(edp))
                fatal("close edp");
        if (dp && (dp->close)(dp))
                fatal("close dp");
        if (makeold) {
                if (fclose(oldfp) == EOF)
                        fatal("close old");
        }

        /* Set master.passwd permissions, in case caller forgot. */
        (void)fchmod(fileno(fp), S_IRUSR|S_IWUSR);
        if (fclose(fp) != 0)
                fatal("fclose");

        /* Install as the real password files. */
        if (!secureonly) {
                (void)snprintf(buf, sizeof(buf), "%s.tmp",
                    changedir(_PATH_MP_DB, basedir));
                mv(buf, changedir(_PATH_MP_DB, basedir));
        }
        (void)snprintf(buf, sizeof(buf), "%s.tmp",
            changedir(_PATH_SMP_DB, basedir));
        mv(buf, changedir(_PATH_SMP_DB, basedir));
        if (makeold) {
                (void)snprintf(buf, sizeof(buf), "%s.orig", pname);
                mv(buf, changedir(_PATH_PASSWD, basedir));
        }

        /*
         * Move the master password LAST -- chpass(1), passwd(1) and vipw(8)
         * all use flock(2) on it to block other incarnations of themselves.
         * The rename means that everything is unlocked, as the original file
         * can no longer be accessed.
         */
        mv(pname, changedir(_PATH_MASTERPASSWD, basedir));
        exit(0);
}

int
scan(FILE *fp, struct passwd *pw, int *flags)
{
        static int lcnt;
        static char line[LINE_MAX];
        char *p;

        if (fgets(line, sizeof(line), fp) == NULL)
                return (0);
        ++lcnt;
        /*
         * ``... if I swallow anything evil, put your fingers down my
         * throat...''
         *      -- The Who
         */
        p = line;
        if (*p != '\0' && *(p += strlen(line) - 1) != '\n') {
                warnx("line too long");
                goto fmt;
        }
        *p = '\0';
        *flags = 0;
        if (!pw_scan(line, pw, flags)) {
                warnx("at line #%d", lcnt);
fmt:            fatalc(EFTYPE, "%s", pname);
        }

        return (1);
}

void
cp(char *from, char *to, mode_t mode)
{
        static char buf[_MAXBSIZE];
        int from_fd, rcount, to_fd, wcount;

        if ((from_fd = open(from, O_RDONLY)) == -1)
                fatal("%s", from);
        if ((to_fd = open(to, O_WRONLY|O_CREAT|O_EXCL, mode)) == -1)
                fatal("%s", to);
        while ((rcount = read(from_fd, buf, sizeof buf)) > 0) {
                wcount = write(to_fd, buf, rcount);
                if (rcount != wcount || wcount == -1)
                        fatal("%s to %s", from, to);
        }
        if (rcount == -1)
                fatal("%s to %s", from, to);
        close(to_fd);
        close(from_fd);
}

void
mv(char *from, char *to)
{
        if (rename(from, to))
                fatal("%s to %s", from, to);
}

void
fatal(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vwarn(fmt, ap);
        va_end(ap);
        cleanup();
        exit(EXIT_FAILURE);
}

void
fatalc(int code, const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vwarnc(code, fmt, ap);
        va_end(ap);
        cleanup();
        exit(EXIT_FAILURE);
}

void
fatalx(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vwarnx(fmt, ap);
        va_end(ap);
        cleanup();
        exit(EXIT_FAILURE);
}

void
cleanup(void)
{
        char buf[PATH_MAX];

        if (clean & FILE_ORIG) {
                (void)snprintf(buf, sizeof(buf), "%s.orig", pname);
                (void)unlink(buf);
        }
        if (clean & FILE_SECURE) {
                (void)snprintf(buf, sizeof(buf), "%s.tmp",
                    changedir(_PATH_SMP_DB, basedir));
                (void)unlink(buf);
        }
        if (clean & FILE_INSECURE) {
                (void)snprintf(buf, sizeof(buf), "%s.tmp",
                    changedir(_PATH_MP_DB, basedir));
                (void)unlink(buf);
        }
}

void
usage(void)
{
        (void)fprintf(stderr,
            "usage: pwd_mkdb [-c] [-p | -s] [-d directory] [-u username] file\n");
        exit(EXIT_FAILURE);
}

char *
changedir(char *path, char *dir)
{
        static char fixed[PATH_MAX];
        char *p;

        if (!dir)
                return (path);

        if ((p = strrchr(path, '/')) != NULL)
                path = p + 1;
        snprintf(fixed, sizeof(fixed), "%s/%s", dir, path);
        return (fixed);
}

int
write_old_entry(FILE *to, const struct passwd *pw)
{
        char gidstr[16], uidstr[16];

        if (to == NULL)
                return (0);

        /* Preserve gid/uid -1 */
        if (pw->pw_gid == (gid_t)-1)
                strlcpy(gidstr, "-1", sizeof(gidstr));
        else
                snprintf(gidstr, sizeof(gidstr), "%u", (u_int)pw->pw_gid);

        if (pw->pw_uid == -1)
                strlcpy(uidstr, "-1", sizeof(uidstr));
        else
                snprintf(uidstr, sizeof(uidstr), "%u", (u_int)pw->pw_uid);

        return (fprintf(to, "%s:*:%s:%s:%s:%s:%s\n", pw->pw_name, uidstr,
            gidstr, pw->pw_gecos, pw->pw_dir, pw->pw_shell));
}

void
db_store(FILE *fp, FILE *oldfp, DB *edp, DB *dp, struct passwd *pw,
         int keytype, char *username, uid_t olduid)
{
        char *p, *t, buf[LINE_MAX * 2], tbuf[_PW_BUF_LEN];
        int flags = 0, dbmode, found = 0;
        static int firsttime = 1;
        DBT data, key;
        size_t len;
        u_int cnt;

        /* If given a username just add that record to the existing db. */
        dbmode = username ? 0 : R_NOOVERWRITE;

        rewind(fp);
        data.data = (u_char *)buf;
        key.data = (u_char *)tbuf;
        for (cnt = 1; scan(fp, pw, &flags); ++cnt) {

                if (firsttime) {
                        /* Look like YP? */
                        if ((pw->pw_name[0] == '+') || (pw->pw_name[0] == '-'))
                                hasyp++;

                        /* Warn about potentially unsafe uid/gid overrides. */
                        if (pw->pw_name[0] == '+') {
                                if (!(flags & _PASSWORD_NOUID) && !pw->pw_uid)
                                        warnx("line %d: superuser override in "
                                            "YP inclusion", cnt);
                                if (!(flags & _PASSWORD_NOGID) && !pw->pw_gid)
                                        warnx("line %d: wheel override in "
                                            "YP inclusion", cnt);
                        }

                        /* Create V7 format password file entry. */
                        if (write_old_entry(oldfp, pw) == -1)
                                fatal("write old");
                }

                /* Are we updating a specific record? */
                if (username) {
                        if (strcmp(username, pw->pw_name) != 0)
                                continue;
                        found = 1;
                        /* If the uid changed, remove the old record by uid. */
                        if (olduid != -1 && olduid != pw->pw_uid) {
                                tbuf[0] = _PW_KEYBYUID;
                                memcpy(tbuf + 1, &olduid, sizeof(olduid));
                                key.size = sizeof(olduid) + 1;
                                (edp->del)(edp, &key, 0);
                                if (dp)
                                        (dp->del)(dp, &key, 0);
                        }
                        /* XXX - should check to see if line number changed. */
                }

                /* Build the key. */
                tbuf[0] = keytype;
                switch (keytype) {
                case _PW_KEYBYNUM:
                        memmove(tbuf + 1, &cnt, sizeof(cnt));
                        key.size = sizeof(cnt) + 1;
                        break;

                case _PW_KEYBYNAME:
                        len = strlen(pw->pw_name);
                        memmove(tbuf + 1, pw->pw_name, len);
                        key.size = len + 1;
                        break;

                case _PW_KEYBYUID:
                        memmove(tbuf + 1, &pw->pw_uid, sizeof(pw->pw_uid));
                        key.size = sizeof(pw->pw_uid) + 1;
                        break;
                }

#define COMPACT(e)      t = e; while ((*p++ = *t++));
                /* Create the secure record. */
                p = buf;
                COMPACT(pw->pw_name);
                COMPACT(pw->pw_passwd);
                memmove(p, &pw->pw_uid, sizeof(uid_t));
                p += sizeof(uid_t);
                memmove(p, &pw->pw_gid, sizeof(gid_t));
                p += sizeof(gid_t);
                memmove(p, &pw->pw_change, sizeof(time_t));
                p += sizeof(time_t);
                COMPACT(pw->pw_class);
                COMPACT(pw->pw_gecos);
                COMPACT(pw->pw_dir);
                COMPACT(pw->pw_shell);
                memmove(p, &pw->pw_expire, sizeof(time_t));
                p += sizeof(time_t);
                memmove(p, &flags, sizeof(int));
                p += sizeof(int);
                data.size = p - buf;

                /* getpwent() does not support entries > _PW_BUF_LEN. */
                if (data.size > _PW_BUF_LEN)
                        fatalx("%s: entry too large", pw->pw_name);

                /* Write the secure record. */
                if ((edp->put)(edp, &key, &data, dbmode) == -1)
                        fatal("put");

                if (dp == NULL)
                        continue;

                /* Star out password to make insecure record. */
                p = buf + strlen(pw->pw_name) + 1;      /* skip pw_name */
                len = strlen(pw->pw_passwd);
                explicit_bzero(p, len);                 /* zero pw_passwd */
                t = p + len + 1;                        /* skip pw_passwd */
                if (len != 0)
                        *p++ = '*';
                *p++ = '\0';
                memmove(p, t, data.size - (t - buf));
                data.size -= len - 1;

                /* Write the insecure record. */
                if ((dp->put)(dp, &key, &data, dbmode) == -1)
                        fatal("put");
        }
        if (firsttime) {
                firsttime = 0;
                if (username && !found && olduid != -1)
                        fatalx("can't find user in master.passwd");
        }
}