xref: /freebsd/contrib/openpam/lib/libpam/openpam_readline.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * Copyright (c) 2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2011 Dag-Erling Smørgrav
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 
36 #ifdef HAVE_CONFIG_H
37 # include "config.h"
38 #endif
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 
43 #include <security/pam_appl.h>
44 
45 #include "openpam_impl.h"
46 
47 #define MIN_LINE_LENGTH 128
48 
49 /*
50  * OpenPAM extension
51  *
52  * Read a line from a file.
53  */
54 
55 char *
56 openpam_readline(FILE *f, int *lineno, size_t *lenp)
57 {
58 	char *line;
59 	size_t len, size;
60 	int ch;
61 
62 	line = NULL;
63 	if (openpam_straddch(&line, &size, &len, 0) != 0)
64 		return (NULL);
65 	for (;;) {
66 		ch = fgetc(f);
67 		/* strip comment */
68 		if (ch == '#') {
69 			do {
70 				ch = fgetc(f);
71 			} while (ch != EOF && ch != '\n');
72 		}
73 		/* eof */
74 		if (ch == EOF) {
75 			/* done */
76 			break;
77 		}
78 		/* eol */
79 		if (ch == '\n') {
80 			if (lineno != NULL)
81 				++*lineno;
82 			/* skip blank lines */
83 			if (len == 0)
84 				continue;
85 			/* continuation */
86 			if (line[len - 1] == '\\') {
87 				line[--len] = '\0';
88 				continue;
89 			}
90 			/* done */
91 			break;
92 		}
93 		/* anything else */
94 		if (openpam_straddch(&line, &size, &len, ch) != 0)
95 			goto fail;
96 	}
97 	if (len == 0)
98 		goto fail;
99 	if (lenp != NULL)
100 		*lenp = len;
101 	return (line);
102 fail:
103 	FREE(line);
104 	return (NULL);
105 }
106 
107 /**
108  * DEPRECATED openpam_readlinev
109  *
110  * The =openpam_readline function reads a line from a file, and returns it
111  * in a NUL-terminated buffer allocated with =!malloc.
112  *
113  * The =openpam_readline function performs a certain amount of processing
114  * on the data it reads:
115  *
116  *  - Comments (introduced by a hash sign) are stripped.
117  *
118  *  - Blank lines are ignored.
119  *
120  *  - If a line ends in a backslash, the backslash is stripped and the
121  *    next line is appended.
122  *
123  * If =lineno is not =NULL, the integer variable it points to is
124  * incremented every time a newline character is read.
125  *
126  * If =lenp is not =NULL, the length of the line (not including the
127  * terminating NUL character) is stored in the variable it points to.
128  *
129  * The caller is responsible for releasing the returned buffer by passing
130  * it to =!free.
131  *
132  * >openpam_readlinev
133  * >openpam_readword
134  */
135