DevComp/zip-rs-wasm
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

feat: Detect insufficient Dir record size

Browse source 
- Per zip spec 4.4.1.4 (https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT)
- If a CentralDirectoryEnd record field cannot hold the
  required data, a ZIP64 record must exist and the
  field will be set to -1(0xFFFF || 0xFFFFFFFF)
- Previously these archives were incorrectly detected as multi-disk
This commit is contained in:
Mikael Pettersson 2023-01-30 11:13:01 +01:00
parent 0dcc40bee0
commit 3fc54cf68c
2 changed files with 16 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
src/read.rs
View file

@ -348,7 +348,9 @@ impl<R: Read + io::Seek> ZipArchive<R> {
Some(locator64) => {
// If we got here, this is indeed a ZIP64 file.
if footer.disk_number as u32 != locator64.disk_with_central_directory {
if !footer.record_too_small()
&& footer.disk_number as u32 != locator64.disk_with_central_directory
{
return unsupported_zip_error(
"Support for multi-disk files is not implemented",
);
@ -401,7 +403,7 @@ impl<R: Read + io::Seek> ZipArchive<R> {
pub fn new(mut reader: R) -> ZipResult<ZipArchive<R>> {
let (footer, cde_start_pos) = spec::CentralDirectoryEnd::find_and_parse(&mut reader)?;
if footer.disk_number != footer.disk_with_central_directory {
if !footer.record_too_small() && footer.disk_number != footer.disk_with_central_directory {
return unsupported_zip_error("Support for multi-disk files is not implemented");
}

12
src/spec.rs
View file

@ -23,6 +23,18 @@ pub struct CentralDirectoryEnd {
}
impl CentralDirectoryEnd {
// Per spec 4.4.1.4 - a CentralDirectoryEnd field might be insufficient to hold the
// required data. In this case the file SHOULD contain a ZIP64 format record
// and the field of this record will be set to -1
pub(crate) fn record_too_small(&self) -> bool {
self.disk_number == 0xFFFF
|| self.disk_with_central_directory == 0xFFFF
|| self.number_of_files_on_this_disk == 0xFFFF
|| self.number_of_files == 0xFFFF
|| self.central_directory_size == 0xFFFFFFFF
|| self.central_directory_offset == 0xFFFFFFFF
}
pub fn parse<T: Read>(reader: &mut T) -> ZipResult<CentralDirectoryEnd> {
let magic = reader.read_u32::<LittleEndian>()?;
if magic != CENTRAL_DIRECTORY_END_SIGNATURE {