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 #include <sys/cdefs.h> 33 __SCCSID("@(#)pw_scan.c 8.3 (Berkeley) 4/2/94"); 34 __FBSDID("$FreeBSD$"); 35 36 /* 37 * This module is used to "verify" password entries by chpass(1) and 38 * pwd_mkdb(8). 39 */ 40 41 #include <sys/param.h> 42 43 #include <err.h> 44 #include <errno.h> 45 #include <pwd.h> 46 #include <string.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 50 #include "pw_scan.h" 51 52 /* 53 * Some software assumes that IDs are short. We should emit warnings 54 * for id's which cannot be stored in a short, but we are more liberal 55 * by default, warning for IDs greater than USHRT_MAX. 56 * 57 * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based 58 * on the existence of PW_SCAN_BIG_IDS in the environment. 59 * 60 * It is believed all baseline system software that can not handle the 61 * normal ID sizes is now gone so pw_big_ids_warning is disabled for now. 62 * But the code has been left in place in case end-users want to re-enable 63 * it and/or for the next time the ID sizes get bigger but pieces of the 64 * system lag behind. 65 */ 66 static int pw_big_ids_warning = 0; 67 68 void 69 __pw_initpwd(struct passwd *pwd) 70 { 71 static char nul[] = ""; 72 73 memset(pwd, 0, sizeof(*pwd)); 74 pwd->pw_uid = (uid_t)-1; /* Considered least likely to lead to */ 75 pwd->pw_gid = (gid_t)-1; /* a security issue. */ 76 pwd->pw_name = nul; 77 pwd->pw_passwd = nul; 78 pwd->pw_class = nul; 79 pwd->pw_gecos = nul; 80 pwd->pw_dir = nul; 81 pwd->pw_shell = nul; 82 } 83 84 int 85 __pw_scan(char *bp, struct passwd *pw, int flags) 86 { 87 uid_t id; 88 int root; 89 char *ep, *p, *sh; 90 unsigned long temp; 91 92 if (pw_big_ids_warning == -1) 93 pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0; 94 95 pw->pw_fields = 0; 96 if (!(pw->pw_name = strsep(&bp, ":"))) /* login */ 97 goto fmt; 98 root = !strcmp(pw->pw_name, "root"); 99 if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0')) 100 pw->pw_fields |= _PWF_NAME; 101 102 if (!(pw->pw_passwd = strsep(&bp, ":"))) /* passwd */ 103 goto fmt; 104 if (pw->pw_passwd[0]) 105 pw->pw_fields |= _PWF_PASSWD; 106 107 if (!(p = strsep(&bp, ":"))) /* uid */ 108 goto fmt; 109 if (p[0]) 110 pw->pw_fields |= _PWF_UID; 111 else { 112 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') { 113 if (flags & _PWSCAN_WARN) 114 warnx("no uid for user %s", pw->pw_name); 115 return (0); 116 } 117 } 118 errno = 0; 119 temp = strtoul(p, &ep, 10); 120 if ((temp == ULONG_MAX && errno == ERANGE) || temp > UID_MAX) { 121 if (flags & _PWSCAN_WARN) 122 warnx("%s > max uid value (%u)", p, UID_MAX); 123 return (0); 124 } 125 id = temp; 126 if (*ep != '\0') { 127 if (flags & _PWSCAN_WARN) 128 warnx("%s uid is incorrect", p); 129 return (0); 130 } 131 if (root && id) { 132 if (flags & _PWSCAN_WARN) 133 warnx("root uid should be 0"); 134 return (0); 135 } 136 if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) { 137 warnx("%s > recommended max uid value (%u)", p, USHRT_MAX); 138 /*return (0);*/ /* THIS SHOULD NOT BE FATAL! */ 139 } 140 pw->pw_uid = id; 141 142 if (!(p = strsep(&bp, ":"))) /* gid */ 143 goto fmt; 144 if (p[0]) 145 pw->pw_fields |= _PWF_GID; 146 else { 147 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') { 148 if (flags & _PWSCAN_WARN) 149 warnx("no gid for user %s", pw->pw_name); 150 return (0); 151 } 152 } 153 errno = 0; 154 temp = strtoul(p, &ep, 10); 155 if ((temp == ULONG_MAX && errno == ERANGE) || temp > GID_MAX) { 156 if (flags & _PWSCAN_WARN) 157 warnx("%s > max gid value (%u)", p, GID_MAX); 158 return (0); 159 } 160 id = temp; 161 if (*ep != '\0') { 162 if (flags & _PWSCAN_WARN) 163 warnx("%s gid is incorrect", p); 164 return (0); 165 } 166 if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) { 167 warnx("%s > recommended max gid value (%u)", p, USHRT_MAX); 168 /* return (0); This should not be fatal! */ 169 } 170 pw->pw_gid = id; 171 172 if (flags & _PWSCAN_MASTER ) { 173 if (!(pw->pw_class = strsep(&bp, ":"))) /* class */ 174 goto fmt; 175 if (pw->pw_class[0]) 176 pw->pw_fields |= _PWF_CLASS; 177 178 if (!(p = strsep(&bp, ":"))) /* change */ 179 goto fmt; 180 if (p[0]) 181 pw->pw_fields |= _PWF_CHANGE; 182 pw->pw_change = atol(p); 183 184 if (!(p = strsep(&bp, ":"))) /* expire */ 185 goto fmt; 186 if (p[0]) 187 pw->pw_fields |= _PWF_EXPIRE; 188 pw->pw_expire = atol(p); 189 } 190 if (!(pw->pw_gecos = strsep(&bp, ":"))) /* gecos */ 191 goto fmt; 192 if (pw->pw_gecos[0]) 193 pw->pw_fields |= _PWF_GECOS; 194 195 if (!(pw->pw_dir = strsep(&bp, ":"))) /* directory */ 196 goto fmt; 197 if (pw->pw_dir[0]) 198 pw->pw_fields |= _PWF_DIR; 199 200 if (!(pw->pw_shell = strsep(&bp, ":"))) /* shell */ 201 goto fmt; 202 203 p = pw->pw_shell; 204 if (root && *p) { /* empty == /bin/sh */ 205 for (setusershell();;) { 206 if (!(sh = getusershell())) { 207 if (flags & _PWSCAN_WARN) 208 warnx("warning, unknown root shell"); 209 break; 210 } 211 if (!strcmp(p, sh)) 212 break; 213 } 214 endusershell(); 215 } 216 if (p[0]) 217 pw->pw_fields |= _PWF_SHELL; 218 219 if ((p = strsep(&bp, ":"))) { /* too many */ 220 fmt: 221 if (flags & _PWSCAN_WARN) 222 warnx("corrupted entry"); 223 return (0); 224 } 225 return (1); 226 } 227