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use crate::result::{ZipError, ZipResult};
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use std::io;
use std::io::prelude::*;
pub const LOCAL_FILE_HEADER_SIGNATURE: u32 = 0x04034b50;
pub const CENTRAL_DIRECTORY_HEADER_SIGNATURE: u32 = 0x02014b50;
const CENTRAL_DIRECTORY_END_SIGNATURE: u32 = 0x06054b50;
pub const ZIP64_CENTRAL_DIRECTORY_END_SIGNATURE: u32 = 0x06064b50;
const ZIP64_CENTRAL_DIRECTORY_END_LOCATOR_SIGNATURE: u32 = 0x07064b50;
pub const ZIP64_BYTES_THR: u64 = u32::MAX as u64;
pub const ZIP64_ENTRY_THR: usize = u16::MAX as usize;
pub struct CentralDirectoryEnd {
pub disk_number: u16,
pub disk_with_central_directory: u16,
pub number_of_files_on_this_disk: u16,
pub number_of_files: u16,
pub central_directory_size: u32,
pub central_directory_offset: u32,
pub zip_file_comment: Vec<u8>,
}
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 {
return Err(ZipError::InvalidArchive("Invalid digital signature header"));
}
let disk_number = reader.read_u16::<LittleEndian>()?;
let disk_with_central_directory = reader.read_u16::<LittleEndian>()?;
let number_of_files_on_this_disk = reader.read_u16::<LittleEndian>()?;
let number_of_files = reader.read_u16::<LittleEndian>()?;
let central_directory_size = reader.read_u32::<LittleEndian>()?;
let central_directory_offset = reader.read_u32::<LittleEndian>()?;
let zip_file_comment_length = reader.read_u16::<LittleEndian>()? as usize;
let mut zip_file_comment = vec![0; zip_file_comment_length];
reader.read_exact(&mut zip_file_comment)?;
Ok(CentralDirectoryEnd {
disk_number,
disk_with_central_directory,
number_of_files_on_this_disk,
number_of_files,
central_directory_size,
central_directory_offset,
zip_file_comment,
})
}
pub fn find_and_parse<T: Read + io::Seek>(
reader: &mut T,
) -> ZipResult<(CentralDirectoryEnd, u64)> {
const HEADER_SIZE: u64 = 22;
const BYTES_BETWEEN_MAGIC_AND_COMMENT_SIZE: u64 = HEADER_SIZE - 6;
let file_length = reader.seek(io::SeekFrom::End(0))?;
let search_upper_bound = file_length.saturating_sub(HEADER_SIZE + ::std::u16::MAX as u64);
if file_length < HEADER_SIZE {
return Err(ZipError::InvalidArchive("Invalid zip header"));
}
let mut pos = file_length - HEADER_SIZE;
while pos >= search_upper_bound {
reader.seek(io::SeekFrom::Start(pos))?;
if reader.read_u32::<LittleEndian>()? == CENTRAL_DIRECTORY_END_SIGNATURE {
reader.seek(io::SeekFrom::Current(
BYTES_BETWEEN_MAGIC_AND_COMMENT_SIZE as i64,
))?;
let cde_start_pos = reader.seek(io::SeekFrom::Start(pos))?;
return CentralDirectoryEnd::parse(reader).map(|cde| (cde, cde_start_pos));
}
pos = match pos.checked_sub(1) {
Some(p) => p,
None => break,
};
}
Err(ZipError::InvalidArchive(
"Could not find central directory end",
))
}
pub fn write<T: Write>(&self, writer: &mut T) -> ZipResult<()> {
writer.write_u32::<LittleEndian>(CENTRAL_DIRECTORY_END_SIGNATURE)?;
writer.write_u16::<LittleEndian>(self.disk_number)?;
writer.write_u16::<LittleEndian>(self.disk_with_central_directory)?;
writer.write_u16::<LittleEndian>(self.number_of_files_on_this_disk)?;
writer.write_u16::<LittleEndian>(self.number_of_files)?;
writer.write_u32::<LittleEndian>(self.central_directory_size)?;
writer.write_u32::<LittleEndian>(self.central_directory_offset)?;
writer.write_u16::<LittleEndian>(self.zip_file_comment.len() as u16)?;
writer.write_all(&self.zip_file_comment)?;
Ok(())
}
}
pub struct Zip64CentralDirectoryEndLocator {
pub disk_with_central_directory: u32,
pub end_of_central_directory_offset: u64,
pub number_of_disks: u32,
}
impl Zip64CentralDirectoryEndLocator {
pub fn parse<T: Read>(reader: &mut T) -> ZipResult<Zip64CentralDirectoryEndLocator> {
let magic = reader.read_u32::<LittleEndian>()?;
if magic != ZIP64_CENTRAL_DIRECTORY_END_LOCATOR_SIGNATURE {
return Err(ZipError::InvalidArchive(
"Invalid zip64 locator digital signature header",
));
}
let disk_with_central_directory = reader.read_u32::<LittleEndian>()?;
let end_of_central_directory_offset = reader.read_u64::<LittleEndian>()?;
let number_of_disks = reader.read_u32::<LittleEndian>()?;
Ok(Zip64CentralDirectoryEndLocator {
disk_with_central_directory,
end_of_central_directory_offset,
number_of_disks,
})
}
pub fn write<T: Write>(&self, writer: &mut T) -> ZipResult<()> {
writer.write_u32::<LittleEndian>(ZIP64_CENTRAL_DIRECTORY_END_LOCATOR_SIGNATURE)?;
writer.write_u32::<LittleEndian>(self.disk_with_central_directory)?;
writer.write_u64::<LittleEndian>(self.end_of_central_directory_offset)?;
writer.write_u32::<LittleEndian>(self.number_of_disks)?;
Ok(())
}
}
pub struct Zip64CentralDirectoryEnd {
pub version_made_by: u16,
pub version_needed_to_extract: u16,
pub disk_number: u32,
pub disk_with_central_directory: u32,
pub number_of_files_on_this_disk: u64,
pub number_of_files: u64,
pub central_directory_size: u64,
pub central_directory_offset: u64,
//pub extensible_data_sector: Vec<u8>, <-- We don't do anything with this at the moment.
}
impl Zip64CentralDirectoryEnd {
pub fn find_and_parse<T: Read + io::Seek>(
reader: &mut T,
nominal_offset: u64,
search_upper_bound: u64,
) -> ZipResult<(Zip64CentralDirectoryEnd, u64)> {
let mut pos = nominal_offset;
while pos <= search_upper_bound {
reader.seek(io::SeekFrom::Start(pos))?;
if reader.read_u32::<LittleEndian>()? == ZIP64_CENTRAL_DIRECTORY_END_SIGNATURE {
let archive_offset = pos - nominal_offset;
let _record_size = reader.read_u64::<LittleEndian>()?;
// We would use this value if we did anything with the "zip64 extensible data sector".
let version_made_by = reader.read_u16::<LittleEndian>()?;
let version_needed_to_extract = reader.read_u16::<LittleEndian>()?;
let disk_number = reader.read_u32::<LittleEndian>()?;
let disk_with_central_directory = reader.read_u32::<LittleEndian>()?;
let number_of_files_on_this_disk = reader.read_u64::<LittleEndian>()?;
let number_of_files = reader.read_u64::<LittleEndian>()?;
let central_directory_size = reader.read_u64::<LittleEndian>()?;
let central_directory_offset = reader.read_u64::<LittleEndian>()?;
return Ok((
Zip64CentralDirectoryEnd {
version_made_by,
version_needed_to_extract,
disk_number,
disk_with_central_directory,
number_of_files_on_this_disk,
number_of_files,
central_directory_size,
central_directory_offset,
},
archive_offset,
));
}
pos += 1;
}
Err(ZipError::InvalidArchive(
"Could not find ZIP64 central directory end",
))
}
pub fn write<T: Write>(&self, writer: &mut T) -> ZipResult<()> {
writer.write_u32::<LittleEndian>(ZIP64_CENTRAL_DIRECTORY_END_SIGNATURE)?;
writer.write_u64::<LittleEndian>(44)?; // record size
writer.write_u16::<LittleEndian>(self.version_made_by)?;
writer.write_u16::<LittleEndian>(self.version_needed_to_extract)?;
writer.write_u32::<LittleEndian>(self.disk_number)?;
writer.write_u32::<LittleEndian>(self.disk_with_central_directory)?;
writer.write_u64::<LittleEndian>(self.number_of_files_on_this_disk)?;
writer.write_u64::<LittleEndian>(self.number_of_files)?;
writer.write_u64::<LittleEndian>(self.central_directory_size)?;
writer.write_u64::<LittleEndian>(self.central_directory_offset)?;
Ok(())
}
}