DevComp/zip-rs-wasm
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Danny McClanahan 2024-05-24 08:26:38 -04:00
parent 80ca254569
commit a509efc28a
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GPG key ID: 6105C10F1A199CC7
1 changed files with 17 additions and 15 deletions
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32
src/spec.rs
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@ -305,7 +305,9 @@ impl Zip32CentralDirectoryEnd {
return Err(ZipError::InvalidArchive("Invalid zip header")); return Err(ZipError::InvalidArchive("Invalid zip header"));
} }
let search_upper_bound = 0; // Arbitrary max length we go back to find the zip32 CDE header.
const MAX_HEADER_AND_COMMENT_SIZE: u64 = 66000;
let search_lower_bound = file_length.saturating_sub(MAX_HEADER_AND_COMMENT_SIZE);
const END_WINDOW_SIZE: usize = 512; const END_WINDOW_SIZE: usize = 512;
/* TODO: use static_assertions!() */ /* TODO: use static_assertions!() */
@ -317,7 +319,7 @@ impl Zip32CentralDirectoryEnd {
let mut window_start: u64 = file_length.saturating_sub(END_WINDOW_SIZE as u64); let mut window_start: u64 = file_length.saturating_sub(END_WINDOW_SIZE as u64);
let mut window = [0u8; END_WINDOW_SIZE]; let mut window = [0u8; END_WINDOW_SIZE];
while window_start >= search_upper_bound { while window_start >= search_lower_bound {
/* Go to the start of the window in the file. */ /* Go to the start of the window in the file. */
reader.seek(io::SeekFrom::Start(window_start))?; reader.seek(io::SeekFrom::Start(window_start))?;
@ -344,7 +346,7 @@ impl Zip32CentralDirectoryEnd {
/* We always want to make sure we go allllll the way back to the start of the file if /* We always want to make sure we go allllll the way back to the start of the file if
* we can't find it elsewhere. However, our `while` condition doesn't check that. So we * we can't find it elsewhere. However, our `while` condition doesn't check that. So we
* avoid infinite looping by checking at the end of the loop. */ * avoid infinite looping by checking at the end of the loop. */
if window_start == search_upper_bound { if window_start == search_lower_bound {
break; break;
} }
/* Shift the window by END_WINDOW_SIZE bytes, but make sure to cover matches that /* Shift the window by END_WINDOW_SIZE bytes, but make sure to cover matches that
@ -361,9 +363,9 @@ impl Zip32CentralDirectoryEnd {
* once (unless limited by file_length). */ * once (unless limited by file_length). */
END_WINDOW_SIZE as u64, END_WINDOW_SIZE as u64,
) )
/* This will never go below the value of `search_upper_bound`, so we have a special /* This will never go below the value of `search_lower_bound`, so we have a special
* `if window_start == search_upper_bound` check above. */ * `if window_start == search_lower_bound` check above. */
.max(search_upper_bound); .max(search_lower_bound);
} }
Err(ZipError::InvalidArchive( Err(ZipError::InvalidArchive(
@ -527,7 +529,7 @@ impl Zip64CentralDirectoryEnd {
pub fn find_and_parse<T: Read + Seek>( pub fn find_and_parse<T: Read + Seek>(
reader: &mut T, reader: &mut T,
nominal_offset: u64, search_lower_bound: u64,
search_upper_bound: u64, search_upper_bound: u64,
) -> ZipResult<Vec<(Zip64CentralDirectoryEnd, u64)>> { ) -> ZipResult<Vec<(Zip64CentralDirectoryEnd, u64)>> {
let mut results = Vec::new(); let mut results = Vec::new();
@ -542,9 +544,9 @@ impl Zip64CentralDirectoryEnd {
let mut window_start: u64 = search_upper_bound let mut window_start: u64 = search_upper_bound
.saturating_sub(END_WINDOW_SIZE as u64) .saturating_sub(END_WINDOW_SIZE as u64)
.max(nominal_offset); .max(search_lower_bound);
let mut window = [0u8; END_WINDOW_SIZE]; let mut window = [0u8; END_WINDOW_SIZE];
while window_start >= nominal_offset { while window_start >= search_lower_bound {
reader.seek(io::SeekFrom::Start(window_start))?; reader.seek(io::SeekFrom::Start(window_start))?;
/* Identify how many bytes to read (this may be less than the window size for files /* Identify how many bytes to read (this may be less than the window size for files
@ -566,8 +568,8 @@ impl Zip64CentralDirectoryEnd {
let cde_start_pos = window_start + offset as u64; let cde_start_pos = window_start + offset as u64;
reader.seek(io::SeekFrom::Start(cde_start_pos))?; reader.seek(io::SeekFrom::Start(cde_start_pos))?;
debug_assert!(cde_start_pos >= nominal_offset); debug_assert!(cde_start_pos >= search_lower_bound);
let archive_offset = cde_start_pos - nominal_offset; let archive_offset = cde_start_pos - search_lower_bound;
let cde = Self::parse(reader)?; let cde = Self::parse(reader)?;
results.push((cde, archive_offset)); results.push((cde, archive_offset));
@ -576,7 +578,7 @@ impl Zip64CentralDirectoryEnd {
/* We always want to make sure we go allllll the way back to the start of the file if /* We always want to make sure we go allllll the way back to the start of the file if
* we can't find it elsewhere. However, our `while` condition doesn't check that. So we * we can't find it elsewhere. However, our `while` condition doesn't check that. So we
* avoid infinite looping by checking at the end of the loop. */ * avoid infinite looping by checking at the end of the loop. */
if window_start == nominal_offset { if window_start == search_lower_bound {
break; break;
} }
/* Shift the window by END_WINDOW_SIZE bytes, but make sure to cover matches that /* Shift the window by END_WINDOW_SIZE bytes, but make sure to cover matches that
@ -594,9 +596,9 @@ impl Zip64CentralDirectoryEnd {
* once (unless limited by search_upper_bound). */ * once (unless limited by search_upper_bound). */
END_WINDOW_SIZE as u64, END_WINDOW_SIZE as u64,
) )
/* This will never go below the value of `nominal_offset`, so we have a special /* This will never go below the value of `search_lower_bound`, so we have a special
* `if window_start == nominal_offset` check above. */ * `if window_start == search_lower_bound` check above. */
.max(nominal_offset); .max(search_lower_bound);
} }
if results.is_empty() { if results.is_empty() {