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