static void
_zip_check_torrentzip(struct zip *za, const struct zip_cdir *cdir)
{
uLong crc_got, crc_should;
char buf[8+1];
char *end;
if (za->zp == NULL || cdir == NULL)
return;
if (_zip_string_length(cdir->comment) != TORRENT_SIG_LEN+8
|| strncmp((const char *)cdir->comment->raw, TORRENT_SIG, TORRENT_SIG_LEN) != 0)
return;
memcpy(buf, cdir->comment->raw+TORRENT_SIG_LEN, 8);
buf[8] = '\0';
errno = 0;
crc_should = strtoul(buf, &end, 16);
if ((crc_should == UINT_MAX && errno != 0) || (end && *end))
return;
if (_zip_filerange_crc(za->zp, cdir->offset, cdir->size, &crc_got, NULL) < 0)
return;
if (crc_got == crc_should)
za->flags |= ZIP_AFL_TORRENT;
}
static int
write_cdir(struct zip *za, struct zip_cdir *cd, FILE *out)
{
off_t offset;
uLong crc;
char buf[TORRENT_CRC_LEN+1];
if (_zip_cdir_write(cd, out, &za->error) < 0)
return -1;
if (zip_get_archive_flag(za, ZIP_AFL_TORRENT, 0) == 0)
return 0;
/* fix up torrentzip comment */
offset = ftello(out);
if (_zip_filerange_crc(out, cd->offset, cd->size, &crc, &za->error) < 0)
return -1;
snprintf(buf, sizeof(buf), "%08lX", (long)crc);
if (fseeko(out, offset-TORRENT_CRC_LEN, SEEK_SET) < 0) {
_zip_error_set(&za->error, ZIP_ER_SEEK, errno);
return -1;
}
if (fwrite(buf, TORRENT_CRC_LEN, 1, out) != 1) {
_zip_error_set(&za->error, ZIP_ER_WRITE, errno);
return -1;
}
return 0;
}
static int
write_cdir(struct zip *za, const struct zip_filelist *filelist, zip_uint64_t survivors, FILE *out)
{
off_t cd_start, end;
zip_int64_t size;
uLong crc;
char buf[TORRENT_CRC_LEN+1];
cd_start = ftello(out);
if ((size=_zip_cdir_write(za, filelist, survivors, out)) < 0)
return -1;
end = ftello(out);
if (zip_get_archive_flag(za, ZIP_AFL_TORRENT, 0) == 0)
return 0;
/* fix up torrentzip comment */
if (_zip_filerange_crc(out, cd_start, size, &crc, &za->error) < 0)
return -1;
snprintf(buf, sizeof(buf), "%08lX", (long)crc);
if (fseeko(out, end-TORRENT_CRC_LEN, SEEK_SET) < 0) {
_zip_error_set(&za->error, ZIP_ER_SEEK, errno);
return -1;
}
if (fwrite(buf, TORRENT_CRC_LEN, 1, out) != 1) {
_zip_error_set(&za->error, ZIP_ER_WRITE, errno);
return -1;
}
return 0;
}