openpam_readline.c revision 1.4 
1/*	$NetBSD: openpam_readline.c,v 1.4 2023/06/30 21:46:20 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2004-2011 Dag-Erling Sm��rgrav
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
38#ifdef HAVE_CONFIG_H
39# include "config.h"
40#endif
41
42#include <sys/cdefs.h>
43__RCSID("$NetBSD: openpam_readline.c,v 1.4 2023/06/30 21:46:20 christos Exp $");
44
45#include <stdio.h>
46#include <stdlib.h>
47
48#include <security/pam_appl.h>
49
50#include "openpam_impl.h"
51
52#define MIN_LINE_LENGTH 128
53
54/*
55 * OpenPAM extension
56 *
57 * Read a line from a file.
58 */
59
60char *
61openpam_readline(FILE *f, int *lineno, size_t *lenp)
62{
63	char *line;
64	size_t len, size;
65	int ch;
66
67	line = NULL;
68	if (openpam_straddch(&line, &size, &len, 0) != 0)
69		return (NULL);
70	for (;;) {
71		ch = fgetc(f);
72		/* strip comment */
73		if (ch == '#') {
74			do {
75				ch = fgetc(f);
76			} while (ch != EOF && ch != '\n');
77		}
78		/* eof */
79		if (ch == EOF) {
80			/* done */
81			break;
82		}
83		/* eol */
84		if (ch == '\n') {
85			if (lineno != NULL)
86				++*lineno;
87			/* skip blank lines */
88			if (len == 0)
89				continue;
90			/* continuation */
91			if (line[len - 1] == '\\') {
92				line[--len] = '\0';
93				continue;
94			}
95			/* done */
96			break;
97		}
98		/* anything else */
99		if (openpam_straddch(&line, &size, &len, ch) != 0)
100			goto fail;
101	}
102	if (len == 0)
103		goto fail;
104	if (lenp != NULL)
105		*lenp = len;
106	return (line);
107fail:
108	FREE(line);
109	return (NULL);
110}
111
112/**
113 * DEPRECATED openpam_readlinev
114 *
115 * The =openpam_readline function reads a line from a file, and returns it
116 * in a NUL-terminated buffer allocated with =!malloc.
117 *
118 * The =openpam_readline function performs a certain amount of processing
119 * on the data it reads:
120 *
121 *  - Comments (introduced by a hash sign) are stripped.
122 *
123 *  - Blank lines are ignored.
124 *
125 *  - If a line ends in a backslash, the backslash is stripped and the
126 *    next line is appended.
127 *
128 * If =lineno is not =NULL, the integer variable it points to is
129 * incremented every time a newline character is read.
130 *
131 * If =lenp is not =NULL, the length of the line (not including the
132 * terminating NUL character) is stored in the variable it points to.
133 *
134 * The caller is responsible for releasing the returned buffer by passing
135 * it to =!free.
136 *
137 * >openpam_readlinev
138 * >openpam_readword
139 */
140