1 /*-
2 * Copyright (c) 2012 Dag-Erling Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $OpenPAM: openpam_straddch.c 938 2017-04-30 21:34:42Z des $
30 */
31
32 #ifdef HAVE_CONFIG_H
33 # include "config.h"
34 #endif
35
36 #include <errno.h>
37 #include <stdlib.h>
38
39 #include <security/pam_appl.h>
40
41 #include "openpam_impl.h"
42
43 #define MIN_STR_SIZE 32
44
45 /*
46 * OpenPAM extension
47 *
48 * Add a character to a string, expanding the buffer if needed.
49 */
50
51 int
openpam_straddch(char ** str,size_t * size,size_t * len,int ch)52 openpam_straddch(char **str, size_t *size, size_t *len, int ch)
53 {
54 size_t tmpsize;
55 char *tmpstr;
56
57 if (*str == NULL) {
58 /* initial allocation */
59 tmpsize = MIN_STR_SIZE;
60 if ((tmpstr = malloc(tmpsize)) == NULL) {
61 openpam_log(PAM_LOG_ERROR, "malloc(): %m");
62 errno = ENOMEM;
63 return (-1);
64 }
65 *str = tmpstr;
66 *size = tmpsize;
67 *len = 0;
68 } else if (ch != 0 && *len + 1 >= *size) {
69 /* additional space required */
70 tmpsize = *size * 2;
71 if ((tmpstr = realloc(*str, tmpsize)) == NULL) {
72 openpam_log(PAM_LOG_ERROR, "realloc(): %m");
73 errno = ENOMEM;
74 return (-1);
75 }
76 *size = tmpsize;
77 *str = tmpstr;
78 }
79 if (ch != 0) {
80 (*str)[*len] = ch;
81 ++*len;
82 }
83 (*str)[*len] = '\0';
84 return (0);
85 }
86
87 /**
88 * The =openpam_straddch function appends a character to a dynamically
89 * allocated NUL-terminated buffer, reallocating the buffer as needed.
90 *
91 * The =str argument points to a variable containing either a pointer to
92 * an existing buffer or =NULL.
93 * If the value of the variable pointed to by =str is =NULL, a new buffer
94 * is allocated.
95 *
96 * The =size and =len argument point to variables used to hold the size
97 * of the buffer and the length of the string it contains, respectively.
98 *
99 * The final argument, =ch, is the character that should be appended to
100 * the string. If =ch is 0, nothing is appended, but a new buffer is
101 * still allocated if =str is NULL. This can be used to "bootstrap" the
102 * string.
103 *
104 * If a new buffer is allocated or an existing buffer is reallocated to
105 * make room for the additional character, =str and =size are updated
106 * accordingly.
107 *
108 * The =openpam_straddch function ensures that the buffer is always
109 * NUL-terminated.
110 *
111 * If the =openpam_straddch function is successful, it increments the
112 * integer variable pointed to by =len (unless =ch was 0) and returns 0.
113 * Otherwise, it leaves the variables pointed to by =str, =size and =len
114 * unmodified, sets :errno to =ENOMEM and returns -1.
115 *
116 * AUTHOR DES
117 */
118