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 30 #ifdef HAVE_CONFIG_H 31 # include "config.h" 32 #endif 33 34 #include <errno.h> 35 #include <stdlib.h> 36 37 #include <security/pam_appl.h> 38 39 #include "openpam_impl.h" 40 41 #define MIN_STR_SIZE 32 42 43 /* 44 * OpenPAM extension 45 * 46 * Add a character to a string, expanding the buffer if needed. 47 */ 48 49 int 50 openpam_straddch(char **str, size_t *size, size_t *len, int ch) 51 { 52 size_t tmpsize; 53 char *tmpstr; 54 55 if (*str == NULL) { 56 /* initial allocation */ 57 tmpsize = MIN_STR_SIZE; 58 if ((tmpstr = malloc(tmpsize)) == NULL) { 59 errno = ENOMEM; 60 return (-1); 61 } 62 *str = tmpstr; 63 *size = tmpsize; 64 *len = 0; 65 } else if (ch != 0 && *len + 1 >= *size) { 66 /* additional space required */ 67 tmpsize = *size * 2; 68 if ((tmpstr = realloc(*str, tmpsize)) == NULL) { 69 errno = ENOMEM; 70 return (-1); 71 } 72 *size = tmpsize; 73 *str = tmpstr; 74 } 75 if (ch != 0) { 76 (*str)[*len] = ch; 77 ++*len; 78 } 79 (*str)[*len] = '\0'; 80 return (0); 81 } 82 83 /** 84 * The =openpam_straddch function appends a character to a dynamically 85 * allocated NUL-terminated buffer, reallocating the buffer as needed. 86 * 87 * The =str argument points to a variable containing either a pointer to 88 * an existing buffer or =NULL. 89 * If the value of the variable pointed to by =str is =NULL, a new buffer 90 * is allocated. 91 * 92 * The =size and =len argument point to variables used to hold the size 93 * of the buffer and the length of the string it contains, respectively. 94 * 95 * The final argument, =ch, is the character that should be appended to 96 * the string. If =ch is 0, nothing is appended, but a new buffer is 97 * still allocated if =str is NULL. This can be used to "bootstrap" the 98 * string. 99 * 100 * If a new buffer is allocated or an existing buffer is reallocated to 101 * make room for the additional character, =str and =size are updated 102 * accordingly. 103 * 104 * The =openpam_straddch function ensures that the buffer is always 105 * NUL-terminated. 106 * 107 * If the =openpam_straddch function is successful, it increments the 108 * integer variable pointed to by =len (unless =ch was 0) and returns 0. 109 * Otherwise, it leaves the variables pointed to by =str, =size and =len 110 * unmodified, sets :errno to =ENOMEM and returns -1. 111 * 112 * AUTHOR DES 113 */ 114