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