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use super::zip_eocd::ZipEOCD;
use super::zip_error::ZipReadError;
use byteorder::{ReadBytesExt, WriteBytesExt, LE};
use bytesize::ByteSize;
use std::io::prelude::*;
use std::io::SeekFrom;
const CD_MAGIC: [u8; 4] = [0x50, 0x4b, 0x1, 0x2];
pub const DATA_ENCRYPTED_FLAG_BIT: u16 = 0x0001;
pub const DATA_DESCRIPTOR_EXISTS_FLAG_BIT: u16 = 0x0008;
pub const UTF8_FLAG_BIT: u16 = 0x0800;
pub struct ZipCDEntry {
pub version_made_by: u16,
pub version_required_to_extract: u16,
pub general_purpose_flags: u16,
pub compression_method: u16,
pub last_mod_time: u16,
pub last_mod_date: u16,
pub crc32: u32,
pub compressed_size: u32,
pub uncompressed_size: u32,
pub file_name_length: u16,
pub extra_field_length: u16,
pub file_comment_length: u16,
pub disk_number_start: u16,
pub internal_file_attributes: u16,
pub external_file_attributes: u32,
pub local_header_position: u32,
pub file_name_raw: Vec<u8>,
pub extra_field: Vec<u8>,
pub file_comment: Vec<u8>,
pub starting_position_with_signature: u64,
pub starting_position_without_signature: u64,
}
impl ZipCDEntry {
fn empty() -> Self {
return Self {
version_made_by: 0,
version_required_to_extract: 0,
general_purpose_flags: 0,
compression_method: 0,
last_mod_time: 0,
last_mod_date: 0,
crc32: 0,
compressed_size: 0,
uncompressed_size: 0,
file_name_length: 0,
extra_field_length: 0,
file_comment_length: 0,
disk_number_start: 0,
internal_file_attributes: 0,
external_file_attributes: 0,
local_header_position: 0,
file_name_raw: vec![],
extra_field: vec![],
file_comment: vec![],
starting_position_with_signature: 0,
starting_position_without_signature: 0,
};
}
fn read_from_eocd_next_signature<T: ReadBytesExt + std::io::Seek>(
&mut self,
read: &mut T,
) -> Result<(), ZipReadError> {
self.starting_position_without_signature = read.seek(SeekFrom::Current(0))?;
self.starting_position_with_signature =
self.starting_position_without_signature - CD_MAGIC.len() as u64;
self.version_made_by = read.read_u16::<LE>()?;
self.version_required_to_extract = read.read_u16::<LE>()?;
self.general_purpose_flags = read.read_u16::<LE>()?;
self.compression_method = read.read_u16::<LE>()?;
self.last_mod_time = read.read_u16::<LE>()?;
self.last_mod_date = read.read_u16::<LE>()?;
self.crc32 = read.read_u32::<LE>()?;
self.compressed_size = read.read_u32::<LE>()?;
self.uncompressed_size = read.read_u32::<LE>()?;
self.file_name_length = read.read_u16::<LE>()?;
self.extra_field_length = read.read_u16::<LE>()?;
self.file_comment_length = read.read_u16::<LE>()?;
self.disk_number_start = read.read_u16::<LE>()?;
self.internal_file_attributes = read.read_u16::<LE>()?;
self.external_file_attributes = read.read_u32::<LE>()?;
self.local_header_position = read.read_u32::<LE>()?;
self.check_unsupported()?;
let read_file_name_length = read
.take(self.file_name_length as u64)
.read_to_end(&mut self.file_name_raw)?;
if read_file_name_length != self.file_name_length as usize {
return Err(ZipReadError::InvalidZipArchive {
reason: format!(
"file name length is invalid (expected from length value field: {} / got: {})",
self.file_name_length, read_file_name_length
),
});
}
let read_extra_field_length = read
.take(self.extra_field_length as u64)
.read_to_end(&mut self.extra_field)?;
if read_extra_field_length != self.extra_field_length as usize {
return Err(ZipReadError::InvalidZipArchive {
reason: format!(
"extra field length is invalid (expected from length value field: {} / got {}",
self.extra_field_length, read_extra_field_length
),
});
}
let read_file_comment_length = read
.take(self.file_comment_length as u64)
.read_to_end(&mut self.file_comment)?;
if read_file_comment_length != self.file_comment_length as usize {
return Err(ZipReadError::InvalidZipArchive {
reason: format!(
"file comment length is invalid (expected from length value field: {} / got {}",
self.file_comment_length, read_file_comment_length
),
});
}
return Ok(());
}
pub fn set_utf8_encoded_flag(&mut self) {
self.general_purpose_flags |= UTF8_FLAG_BIT;
}
pub fn set_file_name_from_slice(&mut self, name: &Vec<u8>) {
self.file_name_length = name.len() as u16;
self.file_name_raw.clone_from(name);
}
pub fn set_file_coment_from_slice(&mut self, comment: &Vec<u8>) {
self.file_comment_length = comment.len() as u16;
self.file_comment.clone_from(comment);
}
pub fn is_encoded_in_utf8(&self) -> bool {
return (UTF8_FLAG_BIT & self.general_purpose_flags) != 0;
}
pub fn is_encrypted_data(&self) -> bool {
return (DATA_ENCRYPTED_FLAG_BIT & self.general_purpose_flags) != 0;
}
pub fn check_unsupported(&self) -> Result<(), ZipReadError> {
if self.disk_number_start != 0 {
return Err(ZipReadError::UnsupportedZipArchive {
reason: "it is one of splitted arvhives".to_string(),
});
}
if self.is_encrypted_data() {
return Err(ZipReadError::UnsupportedZipArchive {
reason: "encrypted data is not supported".to_string(),
});
}
return Ok(());
}
pub fn write<T: WriteBytesExt>(&self, write: &mut T) -> std::io::Result<u64> {
write.write_all(&CD_MAGIC)?;
write.write_u16::<LE>(self.version_made_by)?;
write.write_u16::<LE>(self.version_required_to_extract)?;
write.write_u16::<LE>(self.general_purpose_flags)?;
write.write_u16::<LE>(self.compression_method)?;
write.write_u16::<LE>(self.last_mod_time)?;
write.write_u16::<LE>(self.last_mod_date)?;
write.write_u32::<LE>(self.crc32)?;
write.write_u32::<LE>(self.compressed_size)?;
write.write_u32::<LE>(self.uncompressed_size)?;
write.write_u16::<LE>(self.file_name_length)?;
write.write_u16::<LE>(self.extra_field_length)?;
write.write_u16::<LE>(self.file_comment_length)?;
write.write_u16::<LE>(self.disk_number_start)?;
write.write_u16::<LE>(self.internal_file_attributes)?;
write.write_u32::<LE>(self.external_file_attributes)?;
write.write_u32::<LE>(self.local_header_position)?;
write.write_all(self.file_name_raw.as_slice())?;
write.write_all(self.extra_field.as_slice())?;
write.write_all(self.file_comment.as_slice())?;
return Ok(46
+ self.file_name_length as u64
+ self.extra_field_length as u64
+ self.file_comment_length as u64);
}
fn read_and_generate_from_signature<T: ReadBytesExt + std::io::Seek>(
read: &mut T,
) -> Result<Self, ZipReadError> {
let mut signature_candidate: [u8; 4] = [0; 4];
let start_pos = read.seek(SeekFrom::Current(0))?;
read.read_exact(&mut signature_candidate)?;
if signature_candidate != CD_MAGIC {
return Err(ZipReadError::InvalidZipArchive {
reason: format!(
"assumed central directry signature doesn't appear at position {}",
start_pos
),
});
}
let mut result = Self::empty();
result.read_from_eocd_next_signature(read)?;
return Ok(result);
}
pub fn all_from_eocd<T: ReadBytesExt + std::io::Seek>(
mut read: &mut T,
eocd: &ZipEOCD,
) -> Result<Vec<Self>, ZipReadError> {
read.seek(SeekFrom::Start(eocd.cd_starting_position as u64))?;
let mut result: Vec<Self> = vec![];
for _ in 0..eocd.n_cd_entries {
result.push(Self::read_and_generate_from_signature(&mut read)?);
}
let end_pos = read.seek(SeekFrom::Current(0))?;
if end_pos != eocd.starting_position_with_signature {
return Err(ZipReadError::UnsupportedZipArchive {
reason: format!("there are extra data ({}) between central directory and end of central directory", ByteSize::b(eocd.starting_position_with_signature - end_pos))
});
}
return Ok(result);
}
}