text: /*	$OpenBSD: pwd_mkdb.c,v 1.53 2015/11/05 15:10:11 semarie 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/param.h>	/* MAXBSIZE */
  #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 <limits.h>
  #include <util.h>
  
  #define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))
  
  #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[MAX(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;
  		case '?':
  		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);
  	if (st.st_size / 128 > openinfo.nelem)
  		openinfo.nelem = st.st_size / 128;
  
  	/* 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 = UID_MAX;
  		(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), (uid_t)-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)) < 0)
  			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, 0)) < 0)
  		fatal("%s", from);
  	if ((to_fd = open(to, O_WRONLY|O_CREAT|O_EXCL, mode)) < 0)
  		fatal("%s", to);
  	while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
  		wcount = write(to_fd, buf, rcount);
  		if (rcount != wcount || wcount == -1)
  			fatal("%s to %s", from, to);
  	}
  	if (rcount < 0)
  		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 == (uid_t)-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 != UID_MAX && 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;
  
  		/* 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 != UID_MAX)
  			fatalx("can't find user in master.passwd");
  	}
  }
  