openpam_readline.c revision 236099 
1/*-
2 * Copyright (c) 2003 Networks Associates Technology, Inc.
3 * Copyright (c) 2004-2011 Dag-Erling Sm��rgrav
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by ThinkSec AS and
7 * Network Associates Laboratories, the Security Research Division of
8 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9 * ("CBOSS"), as part of the DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * $Id: openpam_readline.c 596 2012-04-14 14:52:40Z des $
36 */
37
38#ifdef HAVE_CONFIG_H
39# include "config.h"
40#endif
41
42#include <ctype.h>
43#include <stdio.h>
44#include <stdlib.h>
45
46#include <security/pam_appl.h>
47
48#include "openpam_impl.h"
49
50#define MIN_LINE_LENGTH 128
51
52/*
53 * OpenPAM extension
54 *
55 * Read a line from a file.
56 */
57
58char *
59openpam_readline(FILE *f, int *lineno, size_t *lenp)
60{
61	char *line;
62	size_t len, size;
63	int ch;
64
65	if ((line = malloc(size = MIN_LINE_LENGTH)) == NULL) {
66		openpam_log(PAM_LOG_ERROR, "malloc(): %m");
67		return (NULL);
68	}
69	len = 0;
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	openpam_log(PAM_LOG_LIBDEBUG, "returning '%s'", line);
107	return (line);
108fail:
109	FREE(line);
110	return (NULL);
111}
112
113/**
114 * DEPRECATED openpam_readlinev
115 *
116 * The =openpam_readline function reads a line from a file, and returns it
117 * in a NUL-terminated buffer allocated with =!malloc.
118 *
119 * The =openpam_readline function performs a certain amount of processing
120 * on the data it reads:
121 *
122 *  - Comments (introduced by a hash sign) are stripped.
123 *
124 *  - Blank lines are ignored.
125 *
126 *  - If a line ends in a backslash, the backslash is stripped and the
127 *    next line is appended.
128 *
129 * If =lineno is not =NULL, the integer variable it points to is
130 * incremented every time a newline character is read.
131 *
132 * If =lenp is not =NULL, the length of the line (not including the
133 * terminating NUL character) is stored in the variable it points to.
134 *
135 * The caller is responsible for releasing the returned buffer by passing
136 * it to =!free.
137 *
138 * >openpam_readlinev
139 * >openpam_readword
140 */
141