1/* $NetBSD: openpam_straddch.c,v 1.4 2023/06/30 21:46:20 christos Exp $ */ 2 3/*- 4 * Copyright (c) 2012 Dag-Erling Sm��rgrav 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#ifdef HAVE_CONFIG_H 33# include "config.h" 34#endif 35 36#include <sys/cdefs.h> 37__RCSID("$NetBSD: openpam_straddch.c,v 1.4 2023/06/30 21:46:20 christos Exp $"); 38 39#include <errno.h> 40#include <stdlib.h> 41 42#include <security/pam_appl.h> 43 44#include "openpam_impl.h" 45 46#define MIN_STR_SIZE 32 47 48/* 49 * OpenPAM extension 50 * 51 * Add a character to a string, expanding the buffer if needed. 52 */ 53 54int 55openpam_straddch(char **str, size_t *size, size_t *len, int ch) 56{ 57 size_t tmpsize; 58 char *tmpstr; 59 60 if (*str == NULL) { 61 /* initial allocation */ 62 tmpsize = MIN_STR_SIZE; 63 if ((tmpstr = malloc(tmpsize)) == NULL) { 64 errno = ENOMEM; 65 return (-1); 66 } 67 *str = tmpstr; 68 *size = tmpsize; 69 *len = 0; 70 } else if (ch != 0 && *len + 1 >= *size) { 71 /* additional space required */ 72 tmpsize = *size * 2; 73 if ((tmpstr = realloc(*str, tmpsize)) == NULL) { 74 errno = ENOMEM; 75 return (-1); 76 } 77 *size = tmpsize; 78 *str = tmpstr; 79 } 80 if (ch != 0) { 81 (*str)[*len] = (char)ch; 82 ++*len; 83 } 84 (*str)[*len] = '\0'; 85 return (0); 86} 87 88/** 89 * The =openpam_straddch function appends a character to a dynamically 90 * allocated NUL-terminated buffer, reallocating the buffer as needed. 91 * 92 * The =str argument points to a variable containing either a pointer to 93 * an existing buffer or =NULL. 94 * If the value of the variable pointed to by =str is =NULL, a new buffer 95 * is allocated. 96 * 97 * The =size and =len argument point to variables used to hold the size 98 * of the buffer and the length of the string it contains, respectively. 99 * 100 * The final argument, =ch, is the character that should be appended to 101 * the string. If =ch is 0, nothing is appended, but a new buffer is 102 * still allocated if =str is NULL. This can be used to "bootstrap" the 103 * string. 104 * 105 * If a new buffer is allocated or an existing buffer is reallocated to 106 * make room for the additional character, =str and =size are updated 107 * accordingly. 108 * 109 * The =openpam_straddch function ensures that the buffer is always 110 * NUL-terminated. 111 * 112 * If the =openpam_straddch function is successful, it increments the 113 * integer variable pointed to by =len (unless =ch was 0) and returns 0. 114 * Otherwise, it leaves the variables pointed to by =str, =size and =len 115 * unmodified, sets :errno to =ENOMEM and returns -1. 116 * 117 * AUTHOR DES 118 */ 119