From e1ae7d3be6faa710b3a711ed317cfe45d90f28bc Mon Sep 17 00:00:00 2001 From: "Ali H. Fardan" Date: Sun, 21 Aug 2016 00:00:23 +0300 Subject: added bounds checking via secure strl*() routines --- strlcat.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 strlcat.h (limited to 'strlcat.h') diff --git a/strlcat.h b/strlcat.h new file mode 100644 index 0000000..2596420 --- /dev/null +++ b/strlcat.h @@ -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 + * + * 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 +#include + +/* + * 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 */ +} -- cgit v1.2.3