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use crate::result::{ZipError, ZipResult};
use crate::unstable::LittleEndianReadExt;
use core::mem::size_of;
use std::io::Read;
/// Info-ZIP Unicode Path Extra Field (0x7075) or Unicode Comment Extra Field (0x6375), as
/// specified in APPNOTE 4.6.8 and 4.6.9
#[derive(Clone, Debug)]
pub struct UnicodeExtraField {
crc32: u32,
content: Box<[u8]>,
}
impl UnicodeExtraField {
/// Verifies the checksum and returns the content.
pub fn unwrap_valid(self, ascii_field: &[u8]) -> ZipResult<Box<[u8]>> {
let mut crc32 = crc32fast::Hasher::new();
crc32.update(ascii_field);
let actual_crc32 = crc32.finalize();
if self.crc32 != actual_crc32 {
return Err(ZipError::InvalidArchive(
"CRC32 checksum failed on Unicode extra field",
));
}
Ok(self.content)
}
}
impl UnicodeExtraField {
pub(crate) fn try_from_reader<R: Read>(reader: &mut R, len: u16) -> ZipResult<Self> {
// Read and discard version byte
reader.read_exact(&mut [0u8])?;
let crc32 = reader.read_u32_le()?;
let content_len = (len as usize)
.checked_sub(size_of::<u8>() + size_of::<u32>())
.ok_or(ZipError::InvalidArchive("Unicode extra field is too small"))?;
let mut content = vec![0u8; content_len].into_boxed_slice();
reader.read_exact(&mut content)?;
Ok(Self { crc32, content })
}
}