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added bounds checking via secure strl*() routines

This commit is contained in:
Ali H. Fardan 2016-08-21 00:00:23 +03:00
parent 5c86bbd67f
commit e1ae7d3be6
3 changed files with 125 additions and 14 deletions

View file

@ -24,6 +24,12 @@
#include <unistd.h> #include <unistd.h>
#include <X11/Xlib.h> #include <X11/Xlib.h>
#undef strlcat
#undef strlcpy
#include "strlcat.h"
#include "strlcpy.h"
/* statusbar configuration type and struct */ /* statusbar configuration type and struct */
typedef char *(*op_fun) (const char *); typedef char *(*op_fun) (const char *);
struct arg { struct arg {
@ -101,16 +107,16 @@ battery_perc(const char *battery)
FILE *fp; FILE *fp;
/* generate battery nowfile path */ /* generate battery nowfile path */
strcat(batterynowfile, batterypath); strlcat(batterynowfile, batterypath, sizeof(batterynowfile));
strcat(batterynowfile, battery); strlcat(batterynowfile, battery, sizeof(batterynowfile));
strcat(batterynowfile, "/"); strlcat(batterynowfile, "/", sizeof(batterynowfile));
strcat(batterynowfile, batterynow); strlcat(batterynowfile, batterynow, sizeof(batterynowfile));
/* generate battery fullfile path */ /* generate battery fullfile path */
strcat(batteryfullfile, batterypath); strlcat(batteryfullfile, batterypath, sizeof(batteryfullfile));
strcat(batteryfullfile, battery); strlcat(batteryfullfile, battery, sizeof(batteryfullfile));
strcat(batteryfullfile, "/"); strlcat(batteryfullfile, "/", sizeof(batteryfullfile));
strcat(batteryfullfile, batteryfull); strlcat(batteryfullfile, batteryfull, sizeof(batteryfullfile));
/* open battery now file */ /* open battery now file */
if (!(fp = fopen(batterynowfile, "r"))) { if (!(fp = fopen(batterynowfile, "r"))) {
@ -688,9 +694,9 @@ wifi_perc(const char *wificard)
/* generate the path name */ /* generate the path name */
memset(path, 0, sizeof path); memset(path, 0, sizeof path);
strcat(path, "/sys/class/net/"); strlcat(path, "/sys/class/net/", sizeof(path));
strcat(path, wificard); strlcat(path, wificard, sizeof(path));
strcat(path, "/operstate"); strlcat(path, "/operstate", sizeof(path));
/* open wifi file */ /* open wifi file */
if(!(fp = fopen(path, "r"))) { if(!(fp = fopen(path, "r"))) {
@ -716,8 +722,8 @@ wifi_perc(const char *wificard)
} }
/* extract the signal strength */ /* extract the signal strength */
strcpy(needle, wificard); strlcpy(needle, wificard, sizeof(needle));
strcat(needle, ":"); strlcat(needle, ":", sizeof(needle));
fgets(buf, bufsize, fp); fgets(buf, bufsize, fp);
fgets(buf, bufsize, fp); fgets(buf, bufsize, fp);
fgets(buf, bufsize, fp); fgets(buf, bufsize, fp);
@ -794,7 +800,7 @@ main(void)
element = smprintf(unknowntext); element = smprintf(unknowntext);
fprintf(stderr, "Failed to format output.\n"); fprintf(stderr, "Failed to format output.\n");
} }
strcat(status_string, element); strlcat(status_string, element, sizeof(status_string));
free(res); free(res);
free(element); free(element);
} }

55
strlcat.h Normal file
View file

@ -0,0 +1,55 @@
/* $OpenBSD: strlcat.c,v 1.16 2015/08/31 02:53:57 guenther Exp $ */
/*
* Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <string.h>
/*
* Appends src to string dst of size dsize (unlike strncat, dsize is the
* full size of dst, not space left). At most dsize-1 characters
* will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
* Returns strlen(src) + MIN(dsize, strlen(initial dst)).
* If retval >= dsize, truncation occurred.
*/
size_t
strlcat(char *dst, const char *src, size_t dsize)
{
const char *odst = dst;
const char *osrc = src;
size_t n = dsize;
size_t dlen;
/* Find the end of dst and adjust bytes left but don't go past end. */
while (n-- != 0 && *dst != '\0')
dst++;
dlen = dst - odst;
n = dsize - dlen;
if (n-- == 0)
return(dlen + strlen(src));
while (*src != '\0') {
if (n != 0) {
*dst++ = *src;
n--;
}
src++;
}
*dst = '\0';
return(dlen + (src - osrc)); /* count does not include NUL */
}

50
strlcpy.h Normal file
View file

@ -0,0 +1,50 @@
/* $OpenBSD: strlcpy.c,v 1.13 2015/08/31 02:53:57 guenther Exp $ */
/*
* Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <string.h>
/*
* Copy string src to buffer dst of size dsize. At most dsize-1
* chars will be copied. Always NUL terminates (unless dsize == 0).
* Returns strlen(src); if retval >= dsize, truncation occurred.
*/
size_t
strlcpy(char *dst, const char *src, size_t dsize)
{
const char *osrc = src;
size_t nleft = dsize;
/* Copy as many bytes as will fit. */
if (nleft != 0) {
while (--nleft != 0) {
if ((*dst++ = *src++) == '\0')
break;
}
}
/* Not enough room in dst, add NUL and traverse rest of src. */
if (nleft == 0) {
if (dsize != 0)
*dst = '\0'; /* NUL-terminate dst */
while (*src++)
;
}
return(src - osrc - 1); /* count does not include NUL */
}