xref: /netbsd-src/external/bsd/openpam/dist/lib/libpam/openpam_readline.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: openpam_readline.c,v 1.3 2017/05/06 19:50:09 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003 Networks Associates Technology, Inc.
5  * Copyright (c) 2004-2011 Dag-Erling Smørgrav
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by ThinkSec AS and
9  * Network Associates Laboratories, the Security Research Division of
10  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
11  * ("CBOSS"), as part of the DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The name of the author may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * $OpenPAM: openpam_readline.c 938 2017-04-30 21:34:42Z des $
38  */
39 
40 #ifdef HAVE_CONFIG_H
41 # include "config.h"
42 #endif
43 
44 #include <sys/cdefs.h>
45 __RCSID("$NetBSD: openpam_readline.c,v 1.3 2017/05/06 19:50:09 christos Exp $");
46 
47 #include <stdio.h>
48 #include <stdlib.h>
49 
50 #include <security/pam_appl.h>
51 
52 #include "openpam_impl.h"
53 
54 #define MIN_LINE_LENGTH 128
55 
56 /*
57  * OpenPAM extension
58  *
59  * Read a line from a file.
60  */
61 
62 char *
63 openpam_readline(FILE *f, int *lineno, size_t *lenp)
64 {
65 	char *line;
66 	size_t len, size;
67 	int ch;
68 
69 	line = NULL;
70 	if (openpam_straddch(&line, &size, &len, 0) != 0)
71 		return (NULL);
72 	for (;;) {
73 		ch = fgetc(f);
74 		/* strip comment */
75 		if (ch == '#') {
76 			do {
77 				ch = fgetc(f);
78 			} while (ch != EOF && ch != '\n');
79 		}
80 		/* eof */
81 		if (ch == EOF) {
82 			/* done */
83 			break;
84 		}
85 		/* eol */
86 		if (ch == '\n') {
87 			if (lineno != NULL)
88 				++*lineno;
89 			/* skip blank lines */
90 			if (len == 0)
91 				continue;
92 			/* continuation */
93 			if (line[len - 1] == '\\') {
94 				line[--len] = '\0';
95 				continue;
96 			}
97 			/* done */
98 			break;
99 		}
100 		/* anything else */
101 		if (openpam_straddch(&line, &size, &len, ch) != 0)
102 			goto fail;
103 	}
104 	if (len == 0)
105 		goto fail;
106 	if (lenp != NULL)
107 		*lenp = len;
108 	return (line);
109 fail:
110 	FREE(line);
111 	return (NULL);
112 }
113 
114 /**
115  * DEPRECATED openpam_readlinev
116  *
117  * The =openpam_readline function reads a line from a file, and returns it
118  * in a NUL-terminated buffer allocated with =!malloc.
119  *
120  * The =openpam_readline function performs a certain amount of processing
121  * on the data it reads:
122  *
123  *  - Comments (introduced by a hash sign) are stripped.
124  *
125  *  - Blank lines are ignored.
126  *
127  *  - If a line ends in a backslash, the backslash is stripped and the
128  *    next line is appended.
129  *
130  * If =lineno is not =NULL, the integer variable it points to is
131  * incremented every time a newline character is read.
132  *
133  * If =lenp is not =NULL, the length of the line (not including the
134  * terminating NUL character) is stored in the variable it points to.
135  *
136  * The caller is responsible for releasing the returned buffer by passing
137  * it to =!free.
138  *
139  * >openpam_readlinev
140  * >openpam_readword
141  */
142