xref: /openbsd/usr.bin/chpass/edit.c (revision 3bef86f7)
1 /*	$OpenBSD: edit.c,v 1.36 2023/08/11 04:45:05 guenther Exp $	*/
2 /*	$NetBSD: edit.c,v 1.6 1996/05/15 21:50:45 jtc Exp $	*/
3 
4 /*-
5  * Copyright (c) 1990, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/stat.h>
34 
35 #include <ctype.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <paths.h>
40 #include <pwd.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <limits.h>
46 #include <util.h>
47 
48 #include "chpass.h"
49 
50 int
51 edit(char *tempname, struct passwd *pw)
52 {
53 	struct stat begin, end;
54 
55 	for (;;) {
56 		if (lstat(tempname, &begin) == -1 || S_ISLNK(begin.st_mode))
57 			return (EDIT_ERROR);
58 		pw_edit(1, tempname);
59 		if (lstat(tempname, &end) == -1 || S_ISLNK(end.st_mode))
60 			return (EDIT_ERROR);
61 		if (!timespeccmp(&begin.st_mtim, &end.st_mtim, -) &&
62 		    begin.st_size == end.st_size) {
63 			warnx("no changes made");
64 			return (EDIT_NOCHANGE);
65 		}
66 		if (verify(tempname, pw))
67 			break;
68 		pw_prompt();
69 	}
70 	return(EDIT_OK);
71 }
72 
73 /*
74  * display --
75  *	print out the file for the user to edit; strange side-effect:
76  *	set conditional flag if the user gets to edit the shell.
77  */
78 void
79 display(char *tempname, int fd, struct passwd *pw)
80 {
81 	FILE *fp;
82 	char *bp, *p;
83 	char chngstr[256];
84 
85 	if (!(fp = fdopen(fd, "w")))
86 		pw_error(tempname, 1, 1);
87 
88 	(void)fprintf(fp,
89 	    "# Changing user database information for %s.\n", pw->pw_name);
90 	if (!uid) {
91 		(void)fprintf(fp, "Login: %s\n", pw->pw_name);
92 		(void)fprintf(fp, "Encrypted password: %s\n", pw->pw_passwd);
93 		(void)fprintf(fp, "Uid [#]: %u\n", pw->pw_uid);
94 		(void)fprintf(fp, "Gid [# or name]: %u\n", pw->pw_gid);
95 		(void)fprintf(fp, "Change [month day year]: %s\n",
96 		    ttoa(chngstr, sizeof(chngstr), pw->pw_change));
97 		(void)fprintf(fp, "Expire [month day year]: %s\n",
98 		    ttoa(chngstr, sizeof(chngstr), pw->pw_expire));
99 		(void)fprintf(fp, "Class: %s\n", pw->pw_class);
100 		(void)fprintf(fp, "Home directory: %s\n", pw->pw_dir);
101 		(void)fprintf(fp, "Shell: %s\n",
102 		    *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
103 	}
104 	/* Only admin can change "restricted" shells. */
105 	else if (ok_shell(pw->pw_shell, NULL))
106 		/*
107 		 * Make shell a restricted field.  Ugly with a
108 		 * necklace, but there's not much else to do.
109 		 */
110 		(void)fprintf(fp, "Shell: %s\n",
111 		    *pw->pw_shell ? pw->pw_shell : _PATH_BSHELL);
112 	else
113 		list[E_SHELL].restricted = 1;
114 	bp = pw->pw_gecos;
115 	p = strsep(&bp, ",");
116 	(void)fprintf(fp, "Full Name: %s\n", p ? p : "");
117 	p = strsep(&bp, ",");
118 	(void)fprintf(fp, "Office Location: %s\n", p ? p : "");
119 	p = strsep(&bp, ",");
120 	(void)fprintf(fp, "Office Phone: %s\n", p ? p : "");
121 	p = strsep(&bp, ",");
122 	(void)fprintf(fp, "Home Phone: %s\n", p ? p : "");
123 
124 	(void)fchown(fd, getuid(), getgid());
125 	(void)fclose(fp);
126 }
127 
128 int
129 verify(char *tempname, struct passwd *pw)
130 {
131 	unsigned int line;
132 	size_t alen;
133 	static char buf[LINE_MAX];
134 	struct stat sb;
135 	char *p, *q;
136 	ENTRY *ep;
137 	FILE *fp;
138 	int fd;
139 
140 	if ((fd = open(tempname, O_RDONLY|O_NOFOLLOW)) == -1 ||
141 	    (fp = fdopen(fd, "r")) == NULL)
142 		pw_error(tempname, 1, 1);
143 	if (fstat(fd, &sb))
144 		pw_error(tempname, 1, 1);
145 	if (sb.st_size == 0 || sb.st_nlink != 1 || sb.st_uid != uid) {
146 		warnx("corrupted temporary file");
147 		goto bad;
148 	}
149 	line = 0;
150 	while (fgets(buf, sizeof(buf), fp)) {
151 		line++;
152 		if (!buf[0] || buf[0] == '#')
153 			continue;
154 		if ((p = strchr(buf, '\n')) != NULL)
155 			*p = '\0';
156 		else if (!feof(fp)) {
157 			warnx("line %u too long", line);
158 			goto bad;
159 		}
160 		for (ep = list;; ++ep) {
161 			if (!ep->prompt) {
162 				warnx("unrecognized field on line %u", line);
163 				goto bad;
164 			}
165 			if (!strncasecmp(buf, ep->prompt, ep->len)) {
166 				if (ep->restricted && uid) {
167 					warnx(
168 					    "you may not change the %s field",
169 						ep->prompt);
170 					goto bad;
171 				}
172 				if (!(p = strchr(buf, ':'))) {
173 					warnx("line %u corrupted", line);
174 					goto bad;
175 				}
176 				while (isspace((unsigned char)*++p))
177 					;
178 				for (q = p; isprint((unsigned char)*q); q++) {
179 					if (ep->except && strchr(ep->except,*q))
180 						break;
181 				}
182 				if (*q) {
183 					warnx(
184 				   "illegal character in the \"%s\" field",
185 					    ep->prompt);
186 					goto bad;
187 				}
188 				if ((ep->func)(p, pw, ep)) {
189 bad:					(void)fclose(fp);
190 					return (0);
191 				}
192 				break;
193 			}
194 		}
195 	}
196 	(void)fclose(fp);
197 
198 	if (list[E_NAME].save == NULL)
199 		list[E_NAME].save = "";
200 	if (list[E_BPHONE].save == NULL)
201 		list[E_BPHONE].save = "";
202 	if (list[E_HPHONE].save == NULL)
203 		list[E_HPHONE].save = "";
204 	if (list[E_LOCATE].save == NULL)
205 		list[E_LOCATE].save = "";
206 
207 	/* Build the gecos field. */
208 	for (alen = 0, p = list[E_NAME].save; *p; p++)
209 		if (*p == '&')
210 			alen = alen + strlen(pw->pw_name) - 1;
211 	if (asprintf(&p, "%s,%s,%s,%s", list[E_NAME].save,
212 	    list[E_LOCATE].save, list[E_BPHONE].save, list[E_HPHONE].save) == -1)
213 		err(1, NULL);
214 	pw->pw_gecos = p;
215 
216 	if (snprintf(buf, sizeof(buf),
217 	    "%s:%s:%u:%u:%s:%ld:%ld:%s:%s:%s",
218 	    pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, pw->pw_class,
219 	    (long)pw->pw_change, (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir,
220 	    pw->pw_shell) >= 1023 ||
221 	    strlen(buf) + alen >= 1023) {
222 		warnx("entries too long");
223 		free(p);
224 		return (0);
225 	}
226 	free(p);
227 
228 	return (pw_scan(buf, pw, NULL));
229 }
230