cosmopolitan/libc/str/iszipcdir64.c
Justine Tunney 690be544da Make redbean StoreAsset() work better
- Better UBSAN error messages
- POSIX Advisory Locks polyfills
- Move redbean manual to /.help.txt
- System call memory safety in ASAN mode
- Character classification now does UNICODE
2021-05-14 05:44:37 -07:00

46 lines
2.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or 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 "libc/bits/bits.h"
#include "libc/zip.h"
/**
* Returns true if zip64 end of central directory header seems legit.
*/
bool IsZipCdir64(const uint8_t *p, size_t n, size_t i) {
if (i + kZipCdir64HdrMinSize > n) return false;
if (READ32LE(p + i) != kZipCdir64HdrMagic) return false;
if (i + ZIP_CDIR64_HDRSIZE(p + i) + kZipCdir64LocatorSize > n) {
return false;
}
if (ZIP_LOCATE64_MAGIC(p + i + ZIP_CDIR64_HDRSIZE(p + i)) !=
kZipCdir64LocatorMagic) {
return false;
}
if (ZIP_LOCATE64_OFFSET(p + i + ZIP_CDIR64_HDRSIZE(p + i)) != i) {
return false;
}
if (ZIP_CDIR64_RECORDS(p + i) * kZipCfileHdrMinSize >
ZIP_CDIR64_SIZE(p + i)) {
return false;
}
if (ZIP_CDIR64_OFFSET(p + i) + ZIP_CDIR64_SIZE(p + i) > i) {
return false;
}
return true;
}