xref: /freebsd/usr.bin/chpass/util.c (revision fd45b686f9d92f583366c75b22c04c7ee49709c0)
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/types.h>
44 
45 #include <ctype.h>
46 #include <stdint.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <time.h>
51 #include <unistd.h>
52 
53 #include "chpass.h"
54 
55 static const char *months[] =
56 	{ "January", "February", "March", "April", "May", "June",
57 	  "July", "August", "September", "October", "November",
58 	  "December", NULL };
59 
60 char *
61 ttoa(time_t tval)
62 {
63 	struct tm *tp;
64 	static char tbuf[50];
65 
66 	if (tval) {
67 		tp = localtime(&tval);
68 		(void)sprintf(tbuf, "%s %d, %d", months[tp->tm_mon],
69 		    tp->tm_mday, tp->tm_year + 1900);
70 	}
71 	else
72 		*tbuf = '\0';
73 	return (tbuf);
74 }
75 
76 int
77 atot(char *p, time_t *store)
78 {
79 	static struct tm *lt;
80 	char *t;
81 	const char **mp;
82 	time_t tval;
83 	int day, month, year;
84 
85 	if (!*p) {
86 		*store = 0;
87 		return (0);
88 	}
89 	if (!lt) {
90 		unsetenv("TZ");
91 		(void)time(&tval);
92 		lt = localtime(&tval);
93 	}
94 	if (!(t = strtok(p, " \t")))
95 		goto bad;
96 	if (isdigit(*t)) {
97 		month = atoi(t);
98 	} else {
99 		for (mp = months;; ++mp) {
100 			if (!*mp)
101 				goto bad;
102 			if (!strncasecmp(*mp, t, 3)) {
103 				month = mp - months + 1;
104 				break;
105 			}
106 		}
107 	}
108 	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
109 		goto bad;
110 	day = atoi(t);
111 	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
112 		goto bad;
113 	year = atoi(t);
114 	if (day < 1 || day > 31 || month < 1 || month > 12)
115 		goto bad;
116 	/* Allow two digit years 1969-2068 */
117 	if (year < 69)
118 		year += 2000;
119 	else if (year < 100)
120 		year += 1900;
121 	if (year < 1969)
122 bad:		return (1);
123 	lt->tm_year = year - 1900;
124 	lt->tm_mon = month - 1;
125 	lt->tm_mday = day;
126 	lt->tm_hour = 0;
127 	lt->tm_min = 0;
128 	lt->tm_sec = 0;
129 	lt->tm_isdst = -1;
130 	if ((tval = mktime(lt)) < 0)
131 		return (1);
132 #ifndef __i386__
133 	/*
134 	 * PR227589: The pwd.db and spwd.db files store the change and expire
135 	 * dates as unsigned 32-bit ints which overflow in 2106, so larger
136 	 * values must be rejected until the introduction of a v5 password
137 	 * database.  i386 has 32-bit time_t and so dates beyond y2038 are
138 	 * already rejected by mktime above.
139 	 */
140 	if (tval > UINT32_MAX)
141 		return (1);
142 #endif
143 	*store = tval;
144 	return (0);
145 }
146 
147 int
148 ok_shell(char *name)
149 {
150 	char *p, *sh;
151 
152 	setusershell();
153 	while ((sh = getusershell())) {
154 		if (!strcmp(name, sh)) {
155 			endusershell();
156 			return (1);
157 		}
158 		/* allow just shell name, but use "real" path */
159 		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
160 			endusershell();
161 			return (1);
162 		}
163 	}
164 	endusershell();
165 	return (0);
166 }
167 
168 char *
169 dup_shell(char *name)
170 {
171 	char *p, *sh, *ret;
172 
173 	setusershell();
174 	while ((sh = getusershell())) {
175 		if (!strcmp(name, sh)) {
176 			endusershell();
177 			return (strdup(name));
178 		}
179 		/* allow just shell name, but use "real" path */
180 		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
181 			ret = strdup(sh);
182 			endusershell();
183 			return (ret);
184 		}
185 	}
186 	endusershell();
187 	return (NULL);
188 }
189