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 <pwd.h>
  48 #include <string.h>
  49 #include <stdlib.h>
  50 #include <unistd.h>
  51
  52 #include "pw_scan.h"
  53
  54 /*
  55  * Some software assumes that IDs are short.  We should emit warnings
  56  * for id's which cannot be stored in a short, but we are more liberal
  57  * by default, warning for IDs greater than USHRT_MAX.
  58  *
  59  * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based
  60  * on the existence of PW_SCAN_BIG_IDS in the environment.
  61  *
  62  * It is believed all baseline system software that can not handle the
  63  * normal ID sizes is now gone so pw_big_ids_warning is disabled for now.
  64  * But the code has been left in place in case end-users want to re-enable
  65  * it and/or for the next time the ID sizes get bigger but pieces of the
  66  * system lag behind.
  67  */
  68 static int      pw_big_ids_warning = 0;
  69
  70 int
  71 __pw_scan(char *bp, struct passwd *pw, int flags)
  72 {
  73         uid_t id;
  74         int root;
  75         char *ep, *p, *sh;
  76         unsigned long temp;
  77
  78         if (pw_big_ids_warning == -1)
  79                 pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0;
  80
  81         pw->pw_fields = 0;
  82         if (!(pw->pw_name = strsep(&bp, ":")))          /* login */
  83                 goto fmt;
  84         root = !strcmp(pw->pw_name, "root");
  85         if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0'))
  86                 pw->pw_fields |= _PWF_NAME;
  87
  88         if (!(pw->pw_passwd = strsep(&bp, ":")))        /* passwd */
  89                 goto fmt;
  90         if (pw->pw_passwd[0])
  91                 pw->pw_fields |= _PWF_PASSWD;
  92
  93         if (!(p = strsep(&bp, ":")))                    /* uid */
  94                 goto fmt;
  95         if (p[0])
  96                 pw->pw_fields |= _PWF_UID;
  97         else {
  98                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
  99                         if (flags & _PWSCAN_WARN)
 100                                 warnx("no uid for user %s", pw->pw_name);
 101                         return (0);
 102                 }
 103         }
 104         errno = 0;
 105         temp = strtoul(p, &ep, 10);
 106         if ((temp == ULONG_MAX && errno == ERANGE) || temp > UID_MAX) {
 107                 if (flags & _PWSCAN_WARN)
 108                         warnx("%s > max uid value (%u)", p, UID_MAX);
 109                 return (0);
 110         }
 111         id = temp;
 112         if (*ep != '\0') {
 113                 if (flags & _PWSCAN_WARN)
 114                         warnx("%s uid is incorrect", p);
 115                 return (0);
 116         }
 117         if (root && id) {
 118                 if (flags & _PWSCAN_WARN)
 119                         warnx("root uid should be 0");
 120                 return (0);
 121         }
 122         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 123                 warnx("%s > recommended max uid value (%u)", p, USHRT_MAX);
 124                 /*return (0);*/ /* THIS SHOULD NOT BE FATAL! */
 125         }
 126         pw->pw_uid = id;
 127
 128         if (!(p = strsep(&bp, ":")))                    /* gid */
 129                 goto fmt;
 130         if (p[0])
 131                 pw->pw_fields |= _PWF_GID;
 132         else {
 133                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
 134                         if (flags & _PWSCAN_WARN)
 135                                 warnx("no gid for user %s", pw->pw_name);
 136                         return (0);
 137                 }
 138         }
 139         errno = 0;
 140         temp = strtoul(p, &ep, 10);
 141         if ((temp == ULONG_MAX && errno == ERANGE) || temp > GID_MAX) {
 142                 if (flags & _PWSCAN_WARN)
 143                         warnx("%s > max gid value (%u)", p, GID_MAX);
 144                 return (0);
 145         }
 146         id = temp;
 147         if (*ep != '\0') {
 148                 if (flags & _PWSCAN_WARN)
 149                         warnx("%s gid is incorrect", p);
 150                 return (0);
 151         }
 152         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 153                 warnx("%s > recommended max gid value (%u)", p, USHRT_MAX);
 154                 /* return (0); This should not be fatal! */
 155         }
 156         pw->pw_gid = id;
 157
 158         if (flags & _PWSCAN_MASTER ) {
 159                 if (!(pw->pw_class = strsep(&bp, ":"))) /* class */
 160                         goto fmt;
 161                 if (pw->pw_class[0])
 162                         pw->pw_fields |= _PWF_CLASS;
 163
 164                 if (!(p = strsep(&bp, ":")))            /* change */
 165                         goto fmt;
 166                 if (p[0])
 167                         pw->pw_fields |= _PWF_CHANGE;
 168                 pw->pw_change = atol(p);
 169
 170                 if (!(p = strsep(&bp, ":")))            /* expire */
 171                         goto fmt;
 172                 if (p[0])
 173                         pw->pw_fields |= _PWF_EXPIRE;
 174                 pw->pw_expire = atol(p);
 175         }
 176         if (!(pw->pw_gecos = strsep(&bp, ":")))         /* gecos */
 177                 goto fmt;
 178         if (pw->pw_gecos[0])
 179                 pw->pw_fields |= _PWF_GECOS;
 180
 181         if (!(pw->pw_dir = strsep(&bp, ":")))           /* directory */
 182                 goto fmt;
 183         if (pw->pw_dir[0])
 184                 pw->pw_fields |= _PWF_DIR;
 185
 186         if (!(pw->pw_shell = strsep(&bp, ":")))         /* shell */
 187                 goto fmt;
 188
 189         p = pw->pw_shell;
 190         if (root && *p) {                               /* empty == /bin/sh */
 191                 for (setusershell();;) {
 192                         if (!(sh = getusershell())) {
 193                                 if (flags & _PWSCAN_WARN)
 194                                         warnx("warning, unknown root shell");
 195                                 break;
 196                         }
 197                         if (!strcmp(p, sh))
 198                                 break;
 199                 }
 200                 endusershell();
 201         }
 202         if (p[0])
 203                 pw->pw_fields |= _PWF_SHELL;
 204
 205         if ((p = strsep(&bp, ":"))) {                   /* too many */
 206 fmt:
 207                 if (flags & _PWSCAN_WARN)
 208                         warnx("corrupted entry");
 209                 return (0);
 210         }
 211         return (1);
 212 }