1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
//! Structs for reading a ZIP archive

use crate::crc32::Crc32Reader;
use crate::compression::CompressionMethod;
use crate::spec;
use crate::result::{ZipResult, ZipError};
use std::io;
use std::io::prelude::*;
use std::collections::HashMap;
use std::borrow::Cow;

use podio::{ReadPodExt, LittleEndian};
use crate::types::{ZipFileData, System, DateTime};
use crate::cp437::FromCp437;

#[cfg(feature = "deflate")]
use flate2::read::DeflateDecoder;

#[cfg(feature = "bzip2")]
use bzip2::read::BzDecoder;

mod ffi {
    pub const S_IFDIR: u32 = 0o0040000;
    pub const S_IFREG: u32 = 0o0100000;
}

/// Wrapper for reading the contents of a ZIP file.
///
/// ```
/// fn doit() -> zip::result::ZipResult<()>
/// {
///     use std::io::prelude::*;
///
///     // For demonstration purposes we read from an empty buffer.
///     // Normally a File object would be used.
///     let buf: &[u8] = &[0u8; 128];
///     let mut reader = std::io::Cursor::new(buf);
///
///     let mut zip = zip::ZipArchive::new(reader)?;
///
///     for i in 0..zip.len()
///     {
///         let mut file = zip.by_index(i).unwrap();
///         println!("Filename: {}", file.name());
///         let first_byte = file.bytes().next().unwrap()?;
///         println!("{}", first_byte);
///     }
///     Ok(())
/// }
///
/// println!("Result: {:?}", doit());
/// ```
#[derive(Clone, Debug)]
pub struct ZipArchive<R: Read + io::Seek>
{
    reader: R,
    files: Vec<ZipFileData>,
    names_map: HashMap<String, usize>,
    offset: u64,
    comment: Vec<u8>,
}

enum ZipFileReader<'a> {
    NoReader,
    Stored(Crc32Reader<io::Take<&'a mut dyn Read>>),
    #[cfg(feature = "deflate")]
    Deflated(Crc32Reader<flate2::read::DeflateDecoder<io::Take<&'a mut dyn Read>>>),
    #[cfg(feature = "bzip2")]
    Bzip2(Crc32Reader<BzDecoder<io::Take<&'a mut dyn Read>>>),
}

/// A struct for reading a zip file
pub struct ZipFile<'a> {
    data: Cow<'a, ZipFileData>,
    reader: ZipFileReader<'a>,
}

fn unsupported_zip_error<T>(detail: &'static str) -> ZipResult<T>
{
    Err(ZipError::UnsupportedArchive(detail))
}


fn make_reader<'a>(
    compression_method: crate::compression::CompressionMethod,
    crc32: u32,
    reader: io::Take<&'a mut dyn io::Read>)
        -> ZipResult<ZipFileReader<'a>> {

    match compression_method {
        CompressionMethod::Stored =>
        {
            Ok(ZipFileReader::Stored(Crc32Reader::new(
                reader,
                crc32)))
        },
        #[cfg(feature = "deflate")]
        CompressionMethod::Deflated =>
        {
            let deflate_reader = DeflateDecoder::new(reader);
            Ok(ZipFileReader::Deflated(Crc32Reader::new(
                deflate_reader,
                crc32)))
        },
        #[cfg(feature = "bzip2")]
        CompressionMethod::Bzip2 =>
        {
            let bzip2_reader = BzDecoder::new(reader);
            Ok(ZipFileReader::Bzip2(Crc32Reader::new(
                bzip2_reader,
                crc32)))
        },
        _ => unsupported_zip_error("Compression method not supported"),
    }
}

impl<R: Read+io::Seek> ZipArchive<R>
{
    /// Get the directory start offset and number of files. This is done in a
    /// separate function to ease the control flow design.
    fn get_directory_counts(reader: &mut R,
                            footer: &spec::CentralDirectoryEnd,
                            cde_start_pos: u64) -> ZipResult<(u64, u64, usize)> {
        // See if there's a ZIP64 footer. The ZIP64 locator if present will
        // have its signature 20 bytes in front of the standard footer. The
        // standard footer, in turn, is 22+N bytes large, where N is the
        // comment length. Therefore:
        let zip64locator = if reader.seek(io::SeekFrom::End(-(20 + 22 + footer.zip_file_comment.len() as i64))).is_ok() {
            match spec::Zip64CentralDirectoryEndLocator::parse(reader) {
                Ok(loc) => Some(loc),
                Err(ZipError::InvalidArchive(_)) => {
                    // No ZIP64 header; that's actually fine. We're done here.
                    None
                },
                Err(e) => {
                    // Yikes, a real problem
                    return Err(e);
                }
            }
        }
        else {
            // Empty Zip files will have nothing else so this error might be fine. If
            // not, we'll find out soon.
            None
        };

        match zip64locator {
            None => {
                // Some zip files have data prepended to them, resulting in the
                // offsets all being too small. Get the amount of error by comparing
                // the actual file position we found the CDE at with the offset
                // recorded in the CDE.
                let archive_offset = cde_start_pos.checked_sub(footer.central_directory_size as u64)
                    .and_then(|x| x.checked_sub(footer.central_directory_offset as u64))
                    .ok_or(ZipError::InvalidArchive("Invalid central directory size or offset"))?;

                let directory_start = footer.central_directory_offset as u64 + archive_offset;
                let number_of_files = footer.number_of_files_on_this_disk as usize;
                return Ok((archive_offset, directory_start, number_of_files));
            },
            Some(locator64) => {
                // If we got here, this is indeed a ZIP64 file.

                if footer.disk_number as u32 != locator64.disk_with_central_directory {
                    return unsupported_zip_error("Support for multi-disk files is not implemented")
                }

                // We need to reassess `archive_offset`. We know where the ZIP64
                // central-directory-end structure *should* be, but unfortunately we
                // don't know how to precisely relate that location to our current
                // actual offset in the file, since there may be junk at its
                // beginning. Therefore we need to perform another search, as in
                // read::CentralDirectoryEnd::find_and_parse, except now we search
                // forward.

                let search_upper_bound = cde_start_pos
                    .checked_sub(60) // minimum size of Zip64CentralDirectoryEnd + Zip64CentralDirectoryEndLocator
                    .ok_or(ZipError::InvalidArchive("File cannot contain ZIP64 central directory end"))?;
                let (footer, archive_offset) = spec::Zip64CentralDirectoryEnd::find_and_parse(
                    reader,
                    locator64.end_of_central_directory_offset,
                    search_upper_bound)?;

                if footer.disk_number != footer.disk_with_central_directory {
                    return unsupported_zip_error("Support for multi-disk files is not implemented")
                }

                let directory_start = footer.central_directory_offset + archive_offset;
                Ok((archive_offset, directory_start, footer.number_of_files as usize))
            },
        }
    }

    /// Opens a Zip archive and parses the central directory
    pub fn new(mut reader: R) -> ZipResult<ZipArchive<R>> {
        let (footer, cde_start_pos) = spec::CentralDirectoryEnd::find_and_parse(&mut reader)?;

        if footer.disk_number != footer.disk_with_central_directory
        {
            return unsupported_zip_error("Support for multi-disk files is not implemented")
        }

        let (archive_offset, directory_start, number_of_files) =
            Self::get_directory_counts(&mut reader, &footer, cde_start_pos)?;

        let mut files = Vec::new();
        let mut names_map = HashMap::new();

        if let Err(_) = reader.seek(io::SeekFrom::Start(directory_start)) {
            return Err(ZipError::InvalidArchive("Could not seek to start of central directory"));
        }

        for _ in 0 .. number_of_files
        {
            let file = central_header_to_zip_file(&mut reader, archive_offset)?;
            names_map.insert(file.file_name.clone(), files.len());
            files.push(file);
        }

        Ok(ZipArchive {
            reader: reader,
            files: files,
            names_map: names_map,
            offset: archive_offset,
            comment: footer.zip_file_comment,
        })
    }

    /// Number of files contained in this zip.
    ///
    /// ```
    /// fn iter() {
    ///     let mut zip = zip::ZipArchive::new(std::io::Cursor::new(vec![])).unwrap();
    ///
    ///     for i in 0..zip.len() {
    ///         let mut file = zip.by_index(i).unwrap();
    ///         // Do something with file i
    ///     }
    /// }
    /// ```
    pub fn len(&self) -> usize
    {
        self.files.len()
    }

    /// Get the offset from the beginning of the underlying reader that this zip begins at, in bytes.
    ///
    /// Normally this value is zero, but if the zip has arbitrary data prepended to it, then this value will be the size
    /// of that prepended data.
    pub fn offset(&self) -> u64 {
        self.offset
    }

    /// Get the comment of the zip archive.
    pub fn comment(&self) -> &[u8] {
        &self.comment
    }

    /// Returns an iterator over all the file and directory names in this archive.
    pub fn file_names(&self) -> impl Iterator<Item = &str> {
        self.names_map.keys().map(|s| s.as_str())
    }

    /// Search for a file entry by name
    pub fn by_name<'a>(&'a mut self, name: &str) -> ZipResult<ZipFile<'a>>
    {
        let index = match self.names_map.get(name) {
            Some(index) => *index,
            None => { return Err(ZipError::FileNotFound); },
        };
        self.by_index(index)
    }

    /// Get a contained file by index
    pub fn by_index<'a>(&'a mut self, file_number: usize) -> ZipResult<ZipFile<'a>>
    {
        if file_number >= self.files.len() { return Err(ZipError::FileNotFound); }
        let ref mut data = self.files[file_number];

        if data.encrypted
        {
            return unsupported_zip_error("Encrypted files are not supported")
        }

        // Parse local header
        self.reader.seek(io::SeekFrom::Start(data.header_start))?;
        let signature = self.reader.read_u32::<LittleEndian>()?;
        if signature != spec::LOCAL_FILE_HEADER_SIGNATURE
        {
            return Err(ZipError::InvalidArchive("Invalid local file header"))
        }

        self.reader.seek(io::SeekFrom::Current(22))?;
        let file_name_length = self.reader.read_u16::<LittleEndian>()? as u64;
        let extra_field_length = self.reader.read_u16::<LittleEndian>()? as u64;
        let magic_and_header = 4 + 22 + 2 + 2;
        data.data_start = data.header_start + magic_and_header + file_name_length + extra_field_length;

        self.reader.seek(io::SeekFrom::Start(data.data_start))?;
        let limit_reader = (self.reader.by_ref() as &mut dyn Read).take(data.compressed_size);

        Ok(ZipFile { reader: make_reader(data.compression_method, data.crc32, limit_reader)?, data: Cow::Borrowed(data) })
    }

    /// Unwrap and return the inner reader object
    ///
    /// The position of the reader is undefined.
    pub fn into_inner(self) -> R
    {
        self.reader
    }
}

fn central_header_to_zip_file<R: Read+io::Seek>(reader: &mut R, archive_offset: u64) -> ZipResult<ZipFileData>
{
    // Parse central header
    let signature = reader.read_u32::<LittleEndian>()?;
    if signature != spec::CENTRAL_DIRECTORY_HEADER_SIGNATURE
    {
        return Err(ZipError::InvalidArchive("Invalid Central Directory header"))
    }

    let version_made_by = reader.read_u16::<LittleEndian>()?;
    let _version_to_extract = reader.read_u16::<LittleEndian>()?;
    let flags = reader.read_u16::<LittleEndian>()?;
    let encrypted = flags & 1 == 1;
    let is_utf8 = flags & (1 << 11) != 0;
    let compression_method = reader.read_u16::<LittleEndian>()?;
    let last_mod_time = reader.read_u16::<LittleEndian>()?;
    let last_mod_date = reader.read_u16::<LittleEndian>()?;
    let crc32 = reader.read_u32::<LittleEndian>()?;
    let compressed_size = reader.read_u32::<LittleEndian>()?;
    let uncompressed_size = reader.read_u32::<LittleEndian>()?;
    let file_name_length = reader.read_u16::<LittleEndian>()? as usize;
    let extra_field_length = reader.read_u16::<LittleEndian>()? as usize;
    let file_comment_length = reader.read_u16::<LittleEndian>()? as usize;
    let _disk_number = reader.read_u16::<LittleEndian>()?;
    let _internal_file_attributes = reader.read_u16::<LittleEndian>()?;
    let external_file_attributes = reader.read_u32::<LittleEndian>()?;
    let offset = reader.read_u32::<LittleEndian>()? as u64;
    let file_name_raw = ReadPodExt::read_exact(reader, file_name_length)?;
    let extra_field = ReadPodExt::read_exact(reader, extra_field_length)?;
    let file_comment_raw  = ReadPodExt::read_exact(reader, file_comment_length)?;

    let file_name = match is_utf8
    {
        true => String::from_utf8_lossy(&*file_name_raw).into_owned(),
        false => file_name_raw.clone().from_cp437(),
    };
    let file_comment = match is_utf8
    {
        true => String::from_utf8_lossy(&*file_comment_raw).into_owned(),
        false => file_comment_raw.from_cp437(),
    };

    // Construct the result
    let mut result = ZipFileData
    {
        system: System::from_u8((version_made_by >> 8) as u8),
        version_made_by: version_made_by as u8,
        encrypted: encrypted,
        compression_method: CompressionMethod::from_u16(compression_method),
        last_modified_time: DateTime::from_msdos(last_mod_date, last_mod_time),
        crc32: crc32,
        compressed_size: compressed_size as u64,
        uncompressed_size: uncompressed_size as u64,
        file_name: file_name,
        file_name_raw: file_name_raw,
        file_comment: file_comment,
        header_start: offset,
        data_start: 0,
        external_attributes: external_file_attributes,
    };

    match parse_extra_field(&mut result, &*extra_field) {
        Ok(..) | Err(ZipError::Io(..)) => {},
        Err(e) => Err(e)?,
    }

    // Account for shifted zip offsets.
    result.header_start += archive_offset;

    Ok(result)
}

fn parse_extra_field(file: &mut ZipFileData, data: &[u8]) -> ZipResult<()>
{
    let mut reader = io::Cursor::new(data);

    while (reader.position() as usize) < data.len()
    {
        let kind = reader.read_u16::<LittleEndian>()?;
        let len = reader.read_u16::<LittleEndian>()?;
        let mut len_left = len as i64;
        match kind
        {
            // Zip64 extended information extra field
            0x0001 => {
                if file.uncompressed_size == 0xFFFFFFFF {
                    file.uncompressed_size = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
                if file.compressed_size == 0xFFFFFFFF {
                    file.compressed_size = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
                if file.header_start == 0xFFFFFFFF {
                    file.header_start = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
                // Unparsed fields:
                // u32: disk start number
            },
            _ => {},
        }

        // We could also check for < 0 to check for errors
        if len_left > 0 {
            reader.seek(io::SeekFrom::Current(len_left))?;
        }
    }
    Ok(())
}

fn get_reader<'a>(reader: &'a mut ZipFileReader<'_>) -> &'a mut dyn Read {
    match *reader {
        ZipFileReader::NoReader => panic!("ZipFileReader was in an invalid state"),
        ZipFileReader::Stored(ref mut r) => r as &mut dyn Read,
        #[cfg(feature = "deflate")]
        ZipFileReader::Deflated(ref mut r) => r as &mut dyn Read,
        #[cfg(feature = "bzip2")]
        ZipFileReader::Bzip2(ref mut r) => r as &mut dyn Read,
    }
}

/// Methods for retrieving information on zip files
impl<'a> ZipFile<'a> {
    fn get_reader(&mut self) -> &mut dyn Read {
        get_reader(&mut self.reader)
    }
    /// Get the version of the file
    pub fn version_made_by(&self) -> (u8, u8) {
        (self.data.version_made_by / 10, self.data.version_made_by % 10)
    }
    /// Get the name of the file
    pub fn name(&self) -> &str {
        &*self.data.file_name
    }
    /// Get the name of the file, in the raw (internal) byte representation.
    pub fn name_raw(&self) -> &[u8] {
        &*self.data.file_name_raw
    }
    /// Get the name of the file in a sanitized form. It truncates the name to the first NULL byte,
    /// removes a leading '/' and removes '..' parts.
    pub fn sanitized_name(&self) -> ::std::path::PathBuf {
        self.data.file_name_sanitized()
    }
    /// Get the comment of the file
    pub fn comment(&self) -> &str {
        &*self.data.file_comment
    }
    /// Get the compression method used to store the file
    pub fn compression(&self) -> CompressionMethod {
        self.data.compression_method
    }
    /// Get the size of the file in the archive
    pub fn compressed_size(&self) -> u64 {
        self.data.compressed_size
    }
    /// Get the size of the file when uncompressed
    pub fn size(&self) -> u64 {
        self.data.uncompressed_size
    }
    /// Get the time the file was last modified
    pub fn last_modified(&self) -> DateTime {
        self.data.last_modified_time
    }
    /// Returns whether the file is actually a directory
    pub fn is_dir(&self) -> bool {
        self.name().chars().rev().next().map_or(false, |c| c == '/' || c == '\\')
    }
    /// Returns whether the file is a regular file
    pub fn is_file(&self) -> bool {
        !self.is_dir()
    }
    /// Get unix mode for the file
    pub fn unix_mode(&self) -> Option<u32> {
        if self.data.external_attributes == 0 {
            return None;
        }

        match self.data.system {
            System::Unix => {
                Some(self.data.external_attributes >> 16)
            },
            System::Dos => {
                // Interpret MSDOS directory bit
                let mut mode = if 0x10 == (self.data.external_attributes & 0x10) {
                    ffi::S_IFDIR | 0o0775
                } else {
                    ffi::S_IFREG | 0o0664
                };
                if 0x01 == (self.data.external_attributes & 0x01) {
                    // Read-only bit; strip write permissions
                    mode &= 0o0555;
                }
                Some(mode)
            },
            _ => None,
        }
    }
    /// Get the CRC32 hash of the original file
    pub fn crc32(&self) -> u32 {
        self.data.crc32
    }

    /// Get the starting offset of the data of the compressed file
    pub fn data_start(&self) -> u64 {
        self.data.data_start
    }
}

impl<'a> Read for ZipFile<'a> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         self.get_reader().read(buf)
     }
}

impl<'a> Drop for ZipFile<'a> {
    fn drop(&mut self) {
        // self.data is Owned, this reader is constructed by a streaming reader.
        // In this case, we want to exhaust the reader so that the next file is accessible.
        if let Cow::Owned(_) = self.data {
            let mut buffer = [0; 1<<16];

            // Get the inner `Take` reader so all decompression and CRC calculation is skipped.
            let innerreader = ::std::mem::replace(&mut self.reader, ZipFileReader::NoReader);
            let mut reader = match innerreader {
                ZipFileReader::NoReader => panic!("ZipFileReader was in an invalid state"),
                ZipFileReader::Stored(crcreader) => crcreader.into_inner(),
                #[cfg(feature = "deflate")]
                ZipFileReader::Deflated(crcreader) => crcreader.into_inner().into_inner(),
                #[cfg(feature = "bzip2")]
                ZipFileReader::Bzip2(crcreader) => crcreader.into_inner().into_inner(),
            };

            loop {
                match reader.read(&mut buffer) {
                    Ok(0) => break,
                    Ok(_) => (),
                    Err(e) => panic!("Could not consume all of the output of the current ZipFile: {:?}", e),
                }
            }
        }
    }
}

/// Read ZipFile structures from a non-seekable reader.
///
/// This is an alternative method to read a zip file. If possible, use the ZipArchive functions
/// as some information will be missing when reading this manner.
///
/// Reads a file header from the start of the stream. Will return `Ok(Some(..))` if a file is
/// present at the start of the stream. Returns `Ok(None)` if the start of the central directory
/// is encountered. No more files should be read after this.
///
/// The Drop implementation of ZipFile ensures that the reader will be correctly positioned after
/// the structure is done.
///
/// Missing fields are:
/// * `comment`: set to an empty string
/// * `data_start`: set to 0
/// * `external_attributes`: `unix_mode()`: will return None
pub fn read_zipfile_from_stream<'a, R: io::Read>(reader: &'a mut R) -> ZipResult<Option<ZipFile<'_>>> {
    let signature = reader.read_u32::<LittleEndian>()?;

    match signature {
        spec::LOCAL_FILE_HEADER_SIGNATURE => (),
        spec::CENTRAL_DIRECTORY_HEADER_SIGNATURE => return Ok(None),
        _ => return Err(ZipError::InvalidArchive("Invalid local file header")),
    }

    let version_made_by = reader.read_u16::<LittleEndian>()?;
    let flags = reader.read_u16::<LittleEndian>()?;
    let encrypted = flags & 1 == 1;
    let is_utf8 = flags & (1 << 11) != 0;
    let using_data_descriptor = flags & (1 << 3) != 0;
    let compression_method = CompressionMethod::from_u16(reader.read_u16::<LittleEndian>()?);
    let last_mod_time = reader.read_u16::<LittleEndian>()?;
    let last_mod_date = reader.read_u16::<LittleEndian>()?;
    let crc32 = reader.read_u32::<LittleEndian>()?;
    let compressed_size = reader.read_u32::<LittleEndian>()?;
    let uncompressed_size = reader.read_u32::<LittleEndian>()?;
    let file_name_length = reader.read_u16::<LittleEndian>()? as usize;
    let extra_field_length = reader.read_u16::<LittleEndian>()? as usize;

    let file_name_raw = ReadPodExt::read_exact(reader, file_name_length)?;
    let extra_field = ReadPodExt::read_exact(reader, extra_field_length)?;

    let file_name = match is_utf8
    {
        true => String::from_utf8_lossy(&*file_name_raw).into_owned(),
        false => file_name_raw.clone().from_cp437(),
    };

    let mut result = ZipFileData
    {
        system: System::from_u8((version_made_by >> 8) as u8),
        version_made_by: version_made_by as u8,
        encrypted: encrypted,
        compression_method: compression_method,
        last_modified_time: DateTime::from_msdos(last_mod_date, last_mod_time),
        crc32: crc32,
        compressed_size: compressed_size as u64,
        uncompressed_size: uncompressed_size as u64,
        file_name: file_name,
        file_name_raw: file_name_raw,
        file_comment: String::new(),  // file comment is only available in the central directory
        // header_start and data start are not available, but also don't matter, since seeking is
        // not available.
        header_start: 0,
        data_start: 0,
        // The external_attributes field is only available in the central directory.
        // We set this to zero, which should be valid as the docs state 'If input came
        // from standard input, this field is set to zero.'
        external_attributes: 0,
    };

    match parse_extra_field(&mut result, &extra_field) {
        Ok(..) | Err(ZipError::Io(..)) => {},
        Err(e) => Err(e)?,
    }

    if encrypted {
        return unsupported_zip_error("Encrypted files are not supported")
    }
    if using_data_descriptor {
        return unsupported_zip_error("The file length is not available in the local header");
    }

    let limit_reader = (reader as &'a mut dyn io::Read).take(result.compressed_size as u64);

    let result_crc32 = result.crc32;
    let result_compression_method = result.compression_method;
    Ok(Some(ZipFile {
        data: Cow::Owned(result),
        reader: make_reader(result_compression_method, result_crc32, limit_reader)?
    }))
}

#[cfg(test)]
mod test {
    #[test]
    fn invalid_offset() {
        use std::io;
        use super::ZipArchive;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/invalid_offset.zip"));
        let reader = ZipArchive::new(io::Cursor::new(v));
        assert!(reader.is_err());
    }

    #[test]
    fn zip64_with_leading_junk() {
        use std::io;
        use super::ZipArchive;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/zip64_demo.zip"));
        let reader = ZipArchive::new(io::Cursor::new(v)).unwrap();
        assert!(reader.len() == 1);
    }

    #[test]
    fn zip_comment() {
        use std::io;
        use super::ZipArchive;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/mimetype.zip"));
        let reader = ZipArchive::new(io::Cursor::new(v)).unwrap();
        assert!(reader.comment() == b"zip-rs");
    }

    #[test]
    fn zip_read_streaming() {
        use std::io;
        use super::read_zipfile_from_stream;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/mimetype.zip"));
        let mut reader = io::Cursor::new(v);
        loop {
            match read_zipfile_from_stream(&mut reader).unwrap() {
                None => break,
                _ => (),
            }
        }
    }

    #[test]
    fn zip_clone() {
        use std::io::{self, Read};
        use super::ZipArchive;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/mimetype.zip"));
        let mut reader1 = ZipArchive::new(io::Cursor::new(v)).unwrap();
        let mut reader2 = reader1.clone();

        let mut file1 = reader1.by_index(0).unwrap();
        let mut file2 = reader2.by_index(0).unwrap();

        let t = file1.last_modified();
        assert_eq!((t.year(), t.month(), t.day(), t.hour(), t.minute(), t.second()), (1980, 1, 1, 0, 0, 0));

        let mut buf1 = [0; 5];
        let mut buf2 = [0; 5];
        let mut buf3 = [0; 5];
        let mut buf4 = [0; 5];

        file1.read(&mut buf1).unwrap();
        file2.read(&mut buf2).unwrap();
        file1.read(&mut buf3).unwrap();
        file2.read(&mut buf4).unwrap();

        assert_eq!(buf1, buf2);
        assert_eq!(buf3, buf4);
        assert!(buf1 != buf3);
    }

    #[test]
    fn file_and_dir_predicates() {
        use super::ZipArchive;
        use std::io;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/files_and_dirs.zip"));
        let mut zip = ZipArchive::new(io::Cursor::new(v)).unwrap();

        for i in 0..zip.len() {
            let zip_file = zip.by_index(i).unwrap();
            let full_name = zip_file.sanitized_name();
            let file_name = full_name.file_name().unwrap().to_str().unwrap();
            assert!(
                (file_name.starts_with("dir") && zip_file.is_dir())
                    || (file_name.starts_with("file") && zip_file.is_file())
            );
        }
    }
}