xref: /freebsd/usr.bin/chpass/field.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 2002 Networks Associates Technology, Inc.
7  * All rights reserved.
8  *
9  * Portions of this software were developed for the FreeBSD Project by
10  * ThinkSec AS and NAI Labs, the Security Research Division of Network
11  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
12  * ("CBOSS"), as part of the DARPA CHATS research program.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Berkeley and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  */
42 
43 #include <sys/param.h>
44 #include <sys/stat.h>
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <grp.h>
50 #include <paths.h>
51 #include <pwd.h>
52 #include <stdlib.h>
53 #include <string.h>
54 
55 #include "chpass.h"
56 
57 /* ARGSUSED */
58 int
59 p_login(char *p, struct passwd *pw, ENTRY *ep __unused)
60 {
61 	if (!*p) {
62 		warnx("empty login field");
63 		return (-1);
64 	}
65 	if (*p == '-') {
66 		warnx("login names may not begin with a hyphen");
67 		return (-1);
68 	}
69 	if (!(pw->pw_name = strdup(p))) {
70 		warnx("can't save entry");
71 		return (-1);
72 	}
73 	if (strchr(p, '.'))
74 		warnx("\'.\' is dangerous in a login name");
75 	for (; *p; ++p)
76 		if (isupper(*p)) {
77 			warnx("upper-case letters are dangerous in a login name");
78 			break;
79 		}
80 	return (0);
81 }
82 
83 /* ARGSUSED */
84 int
85 p_passwd(char *p, struct passwd *pw, ENTRY *ep __unused)
86 {
87 	if (!(pw->pw_passwd = strdup(p))) {
88 		warnx("can't save password entry");
89 		return (-1);
90 	}
91 
92 	return (0);
93 }
94 
95 /* ARGSUSED */
96 int
97 p_uid(char *p, struct passwd *pw, ENTRY *ep __unused)
98 {
99 	uid_t id;
100 	char *np;
101 
102 	if (!*p) {
103 		warnx("empty uid field");
104 		return (-1);
105 	}
106 	if (!isdigit(*p)) {
107 		warnx("illegal uid");
108 		return (-1);
109 	}
110 	errno = 0;
111 	id = strtoul(p, &np, 10);
112 	if (*np || (id == (uid_t)ULONG_MAX && errno == ERANGE)) {
113 		warnx("illegal uid");
114 		return (-1);
115 	}
116 	pw->pw_uid = id;
117 	return (0);
118 }
119 
120 /* ARGSUSED */
121 int
122 p_gid(char *p, struct passwd *pw, ENTRY *ep __unused)
123 {
124 	struct group *gr;
125 	gid_t id;
126 	char *np;
127 
128 	if (!*p) {
129 		warnx("empty gid field");
130 		return (-1);
131 	}
132 	if (!isdigit(*p)) {
133 		if (!(gr = getgrnam(p))) {
134 			warnx("unknown group %s", p);
135 			return (-1);
136 		}
137 		pw->pw_gid = gr->gr_gid;
138 		return (0);
139 	}
140 	errno = 0;
141 	id = strtoul(p, &np, 10);
142 	if (*np || (id == (uid_t)ULONG_MAX && errno == ERANGE)) {
143 		warnx("illegal gid");
144 		return (-1);
145 	}
146 	pw->pw_gid = id;
147 	return (0);
148 }
149 
150 /* ARGSUSED */
151 int
152 p_class(char *p, struct passwd *pw, ENTRY *ep __unused)
153 {
154 	if (!(pw->pw_class = strdup(p))) {
155 		warnx("can't save entry");
156 		return (-1);
157 	}
158 
159 	return (0);
160 }
161 
162 /* ARGSUSED */
163 int
164 p_change(char *p, struct passwd *pw, ENTRY *ep __unused)
165 {
166 	if (!atot(p, &pw->pw_change))
167 		return (0);
168 	warnx("illegal date for change field");
169 	return (-1);
170 }
171 
172 /* ARGSUSED */
173 int
174 p_expire(char *p, struct passwd *pw, ENTRY *ep __unused)
175 {
176 	if (!atot(p, &pw->pw_expire))
177 		return (0);
178 	warnx("illegal date for expire field");
179 	return (-1);
180 }
181 
182 /* ARGSUSED */
183 int
184 p_gecos(char *p, struct passwd *pw __unused, ENTRY *ep)
185 {
186 	if (!(ep->save = strdup(p))) {
187 		warnx("can't save entry");
188 		return (-1);
189 	}
190 	return (0);
191 }
192 
193 /* ARGSUSED */
194 int
195 p_hdir(char *p, struct passwd *pw, ENTRY *ep __unused)
196 {
197 	if (!*p) {
198 		warnx("empty home directory field");
199 		return (-1);
200 	}
201 	if (!(pw->pw_dir = strdup(p))) {
202 		warnx("can't save entry");
203 		return (-1);
204 	}
205 	return (0);
206 }
207 
208 /* ARGSUSED */
209 int
210 p_shell(char *p, struct passwd *pw, ENTRY *ep __unused)
211 {
212 	struct stat sbuf;
213 
214 	if (!*p) {
215 		pw->pw_shell = strdup(_PATH_BSHELL);
216 		return (0);
217 	}
218 	/* only admin can change from or to "restricted" shells */
219 	if (!master_mode && pw->pw_shell && !ok_shell(pw->pw_shell)) {
220 		warnx("%s: current shell non-standard", pw->pw_shell);
221 		return (-1);
222 	}
223 	if (!ok_shell(p)) {
224 		if (!master_mode) {
225 			warnx("%s: non-standard shell", p);
226 			return (-1);
227 		}
228 		pw->pw_shell = strdup(p);
229 	}
230 	else
231 		pw->pw_shell = dup_shell(p);
232 	if (!pw->pw_shell) {
233 		warnx("can't save entry");
234 		return (-1);
235 	}
236 	if (stat(pw->pw_shell, &sbuf) < 0) {
237 		if (errno == ENOENT)
238 			warnx("WARNING: shell '%s' does not exist",
239 			    pw->pw_shell);
240 		else
241 			warn("WARNING: can't stat shell '%s'",  pw->pw_shell);
242 		return (0);
243 	}
244 	if (!S_ISREG(sbuf.st_mode)) {
245 		warnx("WARNING: shell '%s' is not a regular file",
246 			pw->pw_shell);
247 		return (0);
248 	}
249 	if ((sbuf.st_mode & (S_IXOTH | S_IXGRP | S_IXUSR)) == 0) {
250 		warnx("WARNING: shell '%s' is not executable", pw->pw_shell);
251 		return (0);
252 	}
253 	return (0);
254 }
255