libc/gen/pw_scan.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 static char sccsid[] = "@(#)pw_scan.c   8.3 (Berkeley) 4/2/94";
  34 #endif /* LIBC_SCCS and not lint */
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 /*
  39  * This module is used to "verify" password entries by chpass(1) and
  40  * pwd_mkdb(8).
  41  */
  42
  43 #include <sys/param.h>
  44
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <pwd.h>
  49 #include <stdio.h>
  50 #include <string.h>
  51 #include <stdlib.h>
  52 #include <unistd.h>
  53
  54 #include "pw_scan.h"
  55
  56 /*
  57  * Some software assumes that IDs are short.  We should emit warnings
  58  * for id's which cannot be stored in a short, but we are more liberal
  59  * by default, warning for IDs greater than USHRT_MAX.
  60  *
  61  * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based
  62  * on the existence of PW_SCAN_BIG_IDS in the environment.
  63  *
  64  * It is believed all baseline system software that can not handle the
  65  * normal ID sizes is now gone so pw_big_ids_warning is disabled for now.
  66  * But the code has been left in place in case end-users want to re-enable
  67  * it and/or for the next time the ID sizes get bigger but pieces of the
  68  * system lag behind.
  69  */
  70 static int      pw_big_ids_warning = 0;
  71
  72 int
  73 __pw_scan(char *bp, struct passwd *pw, int flags)
  74 {
  75         uid_t id;
  76         int root;
  77         char *ep, *p, *sh;
  78         unsigned long temp;
  79
  80         if (pw_big_ids_warning == -1)
  81                 pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0;
  82
  83         pw->pw_fields = 0;
  84         if (!(pw->pw_name = strsep(&bp, ":")))          /* login */
  85                 goto fmt;
  86         root = !strcmp(pw->pw_name, "root");
  87         if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0'))
  88                 pw->pw_fields |= _PWF_NAME;
  89
  90         if (!(pw->pw_passwd = strsep(&bp, ":")))        /* passwd */
  91                 goto fmt;
  92         if (pw->pw_passwd[0])
  93                 pw->pw_fields |= _PWF_PASSWD;
  94
  95         if (!(p = strsep(&bp, ":")))                    /* uid */
  96                 goto fmt;
  97         if (p[0])
  98                 pw->pw_fields |= _PWF_UID;
  99         else {
 100                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
 101                         if (flags & _PWSCAN_WARN)
 102                                 warnx("no uid for user %s", pw->pw_name);
 103                         return (0);
 104                 }
 105         }
 106         errno = 0;
 107         temp = strtoul(p, &ep, 10);
 108         if ((temp == ULONG_MAX && errno == ERANGE) || temp > UID_MAX) {
 109                 if (flags & _PWSCAN_WARN)
 110                         warnx("%s > max uid value (%u)", p, UID_MAX);
 111                 return (0);
 112         }
 113         id = temp;
 114         if (*ep != '\0') {
 115                 if (flags & _PWSCAN_WARN)
 116                         warnx("%s uid is incorrect", p);
 117                 return (0);
 118         }
 119         if (root && id) {
 120                 if (flags & _PWSCAN_WARN)
 121                         warnx("root uid should be 0");
 122                 return (0);
 123         }
 124         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 125                 warnx("%s > recommended max uid value (%u)", p, USHRT_MAX);
 126                 /*return (0);*/ /* THIS SHOULD NOT BE FATAL! */
 127         }
 128         pw->pw_uid = id;
 129
 130         if (!(p = strsep(&bp, ":")))                    /* gid */
 131                 goto fmt;
 132         if (p[0])
 133                 pw->pw_fields |= _PWF_GID;
 134         else {
 135                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
 136                         if (flags & _PWSCAN_WARN)
 137                                 warnx("no gid for user %s", pw->pw_name);
 138                         return (0);
 139                 }
 140         }
 141         errno = 0;
 142         temp = strtoul(p, &ep, 10);
 143         if ((temp == ULONG_MAX && errno == ERANGE) || temp > GID_MAX) {
 144                 if (flags & _PWSCAN_WARN)
 145                         warnx("%s > max gid value (%u)", p, GID_MAX);
 146                 return (0);
 147         }
 148         id = temp;
 149         if (*ep != '\0') {
 150                 if (flags & _PWSCAN_WARN)
 151                         warnx("%s gid is incorrect", p);
 152                 return (0);
 153         }
 154         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 155                 warnx("%s > recommended max gid value (%u)", p, USHRT_MAX);
 156                 /* return (0); This should not be fatal! */
 157         }
 158         pw->pw_gid = id;
 159
 160         if (flags & _PWSCAN_MASTER ) {
 161                 if (!(pw->pw_class = strsep(&bp, ":"))) /* class */
 162                         goto fmt;
 163                 if (pw->pw_class[0])
 164                         pw->pw_fields |= _PWF_CLASS;
 165
 166                 if (!(p = strsep(&bp, ":")))            /* change */
 167                         goto fmt;
 168                 if (p[0])
 169                         pw->pw_fields |= _PWF_CHANGE;
 170                 pw->pw_change = atol(p);
 171
 172                 if (!(p = strsep(&bp, ":")))            /* expire */
 173                         goto fmt;
 174                 if (p[0])
 175                         pw->pw_fields |= _PWF_EXPIRE;
 176                 pw->pw_expire = atol(p);
 177         }
 178         if (!(pw->pw_gecos = strsep(&bp, ":")))         /* gecos */
 179                 goto fmt;
 180         if (pw->pw_gecos[0])
 181                 pw->pw_fields |= _PWF_GECOS;
 182
 183         if (!(pw->pw_dir = strsep(&bp, ":")))           /* directory */
 184                 goto fmt;
 185         if (pw->pw_dir[0])
 186                 pw->pw_fields |= _PWF_DIR;
 187
 188         if (!(pw->pw_shell = strsep(&bp, ":")))         /* shell */
 189                 goto fmt;
 190
 191         p = pw->pw_shell;
 192         if (root && *p) {                               /* empty == /bin/sh */
 193                 for (setusershell();;) {
 194                         if (!(sh = getusershell())) {
 195                                 if (flags & _PWSCAN_WARN)
 196                                         warnx("warning, unknown root shell");
 197                                 break;
 198                         }
 199                         if (!strcmp(p, sh))
 200                                 break;
 201                 }
 202                 endusershell();
 203         }
 204         if (p[0])
 205                 pw->pw_fields |= _PWF_SHELL;
 206
 207         if ((p = strsep(&bp, ":"))) {                   /* too many */
 208 fmt:
 209                 if (flags & _PWSCAN_WARN)
 210                         warnx("corrupted entry");
 211                 return (0);
 212         }
 213         return (1);
 214 }