busybox/archival/libarchive/unsafe_prefix.c
Denys Vlasenko 8c06bc6ba1 unzip: prevent attacks via malicious filenames
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-02-10 01:30:43 +01:00

37 lines
631 B
C

/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "bb_archive.h"
const char* FAST_FUNC strip_unsafe_prefix(const char *str)
{
const char *cp = str;
while (1) {
char *cp2;
if (*cp == '/') {
cp++;
continue;
}
if (strncmp(cp, "/../"+1, 3) == 0) {
cp += 3;
continue;
}
cp2 = strstr(cp, "/../");
if (!cp2)
break;
cp = cp2 + 4;
}
if (cp != str) {
static smallint warned = 0;
if (!warned) {
warned = 1;
bb_error_msg("removing leading '%.*s' from member names",
(int)(cp - str), str);
}
}
return cp;
}