xref: /freebsd/lib/libc/gen/pw_scan.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)pw_scan.c	8.3 (Berkeley) 4/2/94";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
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 <fcntl.h>
46 #include <pwd.h>
47 #include <stdio.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 }
213