From 00378bc6f2b782af32a249082d1806ee13850ab0 Mon Sep 17 00:00:00 2001
From: Chris Hennick <hennickc@amazon.com>
Date: Tue, 23 Apr 2024 12:07:30 -0700
Subject: [PATCH] fix: Alignment was previously handled incorrectly (#33)
---
src/read.rs | 2 +-
src/write.rs | 33 ++++++++++++++++++++++-----------
2 files changed, 23 insertions(+), 12 deletions(-)
diff --git a/src/read.rs b/src/read.rs
index dac4df58..fdebcad9 100644
--- a/src/read.rs
+++ b/src/read.rs
@@ -1447,7 +1447,7 @@ mod test {
v.extend_from_slice(include_bytes!("../tests/data/deflate64_issue_25.zip"));
ZipArchive::new(Cursor::new(v)).expect_err("Invalid file");
}
-
+
#[test]
fn test_read_with_data_descriptor() {
let mut v = Vec::new();
diff --git a/src/write.rs b/src/write.rs
index 5d85d5ad..aaa6b3a5 100644
--- a/src/write.rs
+++ b/src/write.rs
@@ -761,25 +761,36 @@ impl<W: Write + Seek> ZipWriter<W> {
let mut header_end = writer.stream_position()?;
if options.alignment > 1 {
let align = options.alignment as u64;
- if header_end % align != 0 {
- let pad_length = (align - (header_end + 4) % align) % align;
- if pad_length + extra_field_length as u64 > u16::MAX as u64 {
+ let unaligned_header_bytes = header_end % align;
+ if unaligned_header_bytes != 0 {
+ let pad_length = (align - unaligned_header_bytes) as usize;
+ let Some(new_extra_field_length) =
+ (pad_length as u16).checked_add(extra_field_length)
+ else {
let _ = self.abort_file();
return Err(InvalidArchive(
"Extra data field would be larger than allowed after aligning",
));
+ };
+ if pad_length >= 4 {
+ // Add an extra field to the extra_data
+ let pad_body = vec![0; pad_length - 4];
+ writer.write_all(b"za").map_err(ZipError::from)?; // 0x617a
+ writer
+ .write_u16::<LittleEndian>(pad_body.len() as u16)
+ .map_err(ZipError::from)?;
+ writer.write_all(&pad_body).map_err(ZipError::from)?;
+ } else {
+ // extra_data padding is too small for an extra field header, so pad with
+ // zeroes
+ let pad = vec![0; pad_length];
+ writer.write_all(&pad).map_err(ZipError::from)?;
}
- let pad = vec![0; pad_length as usize];
- writer.write_all(b"za").map_err(ZipError::from)?; // 0x617a
- writer
- .write_u16::<LittleEndian>(pad.len() as u16)
- .map_err(ZipError::from)?;
- writer.write_all(&pad).map_err(ZipError::from)?;
header_end = writer.stream_position()?;
// Update extra field length in local file header.
writer.seek(SeekFrom::Start(file.header_start + 28))?;
- writer.write_u16::<LittleEndian>(pad_length as u16 + extra_field_length)?;
+ writer.write_u16::<LittleEndian>(new_extra_field_length)?;
writer.seek(SeekFrom::Start(header_end))?;
debug_assert_eq!(header_end % align, 0);
}
@@ -2210,7 +2221,7 @@ mod test {
writer.finish()?;
Ok(())
}
-
+
#[test]
fn test_alignment() {
let page_size = 4096;