xref: /freebsd/usr.bin/chpass/util.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
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 #ifndef lint
44 #endif /* not lint */
45 #include <sys/cdefs.h>
46 #include <sys/types.h>
47 
48 #include <ctype.h>
49 #include <stdint.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <time.h>
54 #include <unistd.h>
55 
56 #include "chpass.h"
57 
58 static const char *months[] =
59 	{ "January", "February", "March", "April", "May", "June",
60 	  "July", "August", "September", "October", "November",
61 	  "December", NULL };
62 
63 char *
64 ttoa(time_t tval)
65 {
66 	struct tm *tp;
67 	static char tbuf[50];
68 
69 	if (tval) {
70 		tp = localtime(&tval);
71 		(void)sprintf(tbuf, "%s %d, %d", months[tp->tm_mon],
72 		    tp->tm_mday, tp->tm_year + 1900);
73 	}
74 	else
75 		*tbuf = '\0';
76 	return (tbuf);
77 }
78 
79 int
80 atot(char *p, time_t *store)
81 {
82 	static struct tm *lt;
83 	char *t;
84 	const char **mp;
85 	time_t tval;
86 	int day, month, year;
87 
88 	if (!*p) {
89 		*store = 0;
90 		return (0);
91 	}
92 	if (!lt) {
93 		unsetenv("TZ");
94 		(void)time(&tval);
95 		lt = localtime(&tval);
96 	}
97 	if (!(t = strtok(p, " \t")))
98 		goto bad;
99 	if (isdigit(*t)) {
100 		month = atoi(t);
101 	} else {
102 		for (mp = months;; ++mp) {
103 			if (!*mp)
104 				goto bad;
105 			if (!strncasecmp(*mp, t, 3)) {
106 				month = mp - months + 1;
107 				break;
108 			}
109 		}
110 	}
111 	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
112 		goto bad;
113 	day = atoi(t);
114 	if (!(t = strtok(NULL, " \t,")) || !isdigit(*t))
115 		goto bad;
116 	year = atoi(t);
117 	if (day < 1 || day > 31 || month < 1 || month > 12)
118 		goto bad;
119 	/* Allow two digit years 1969-2068 */
120 	if (year < 69)
121 		year += 2000;
122 	else if (year < 100)
123 		year += 1900;
124 	if (year < 1969)
125 bad:		return (1);
126 	lt->tm_year = year - 1900;
127 	lt->tm_mon = month - 1;
128 	lt->tm_mday = day;
129 	lt->tm_hour = 0;
130 	lt->tm_min = 0;
131 	lt->tm_sec = 0;
132 	lt->tm_isdst = -1;
133 	if ((tval = mktime(lt)) < 0)
134 		return (1);
135 #ifndef __i386__
136 	/*
137 	 * PR227589: The pwd.db and spwd.db files store the change and expire
138 	 * dates as unsigned 32-bit ints which overflow in 2106, so larger
139 	 * values must be rejected until the introduction of a v5 password
140 	 * database.  i386 has 32-bit time_t and so dates beyond y2038 are
141 	 * already rejected by mktime above.
142 	 */
143 	if (tval > UINT32_MAX)
144 		return (1);
145 #endif
146 	*store = tval;
147 	return (0);
148 }
149 
150 int
151 ok_shell(char *name)
152 {
153 	char *p, *sh;
154 
155 	setusershell();
156 	while ((sh = getusershell())) {
157 		if (!strcmp(name, sh)) {
158 			endusershell();
159 			return (1);
160 		}
161 		/* allow just shell name, but use "real" path */
162 		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
163 			endusershell();
164 			return (1);
165 		}
166 	}
167 	endusershell();
168 	return (0);
169 }
170 
171 char *
172 dup_shell(char *name)
173 {
174 	char *p, *sh, *ret;
175 
176 	setusershell();
177 	while ((sh = getusershell())) {
178 		if (!strcmp(name, sh)) {
179 			endusershell();
180 			return (strdup(name));
181 		}
182 		/* allow just shell name, but use "real" path */
183 		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
184 			ret = strdup(sh);
185 			endusershell();
186 			return (ret);
187 		}
188 	}
189 	endusershell();
190 	return (NULL);
191 }
192