Home | History | Annotate | Line # | Download | only in libpam 
      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 Smrgrav
      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 
     60 char *
     61 openpam_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);
    107 fail:
    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