summaryrefslogtreecommitdiffstats
path: root/third_party/rust/zip/src/read.rs
blob: dad20c260b27592124ff01a61ebaf234c95570f1 (plain)
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
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
//! Types for reading ZIP archives

#[cfg(feature = "aes-crypto")]
use crate::aes::{AesReader, AesReaderValid};
use crate::compression::CompressionMethod;
use crate::cp437::FromCp437;
use crate::crc32::Crc32Reader;
use crate::result::{InvalidPassword, ZipError, ZipResult};
use crate::spec;
use crate::types::{AesMode, AesVendorVersion, AtomicU64, DateTime, System, ZipFileData};
use crate::zipcrypto::{ZipCryptoReader, ZipCryptoReaderValid, ZipCryptoValidator};
use byteorder::{LittleEndian, ReadBytesExt};
use std::borrow::Cow;
use std::collections::HashMap;
use std::io::{self, prelude::*};
use std::path::{Component, Path};
use std::sync::Arc;

#[cfg(any(
    feature = "deflate",
    feature = "deflate-miniz",
    feature = "deflate-zlib"
))]
use flate2::read::DeflateDecoder;

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

#[cfg(feature = "zstd")]
use zstd::stream::read::Decoder as ZstdDecoder;

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

// Put the struct declaration in a private module to convince rustdoc to display ZipArchive nicely
pub(crate) mod zip_archive {
    /// Extract immutable data from `ZipArchive` to make it cheap to clone
    #[derive(Debug)]
    pub(crate) struct Shared {
        pub(super) files: Vec<super::ZipFileData>,
        pub(super) names_map: super::HashMap<String, usize>,
        pub(super) offset: u64,
        pub(super) comment: Vec<u8>,
    }

    /// ZIP archive reader
    ///
    /// At the moment, this type is cheap to clone if this is the case for the
    /// reader it uses. However, this is not guaranteed by this crate and it may
    /// change in the future.
    ///
    /// ```no_run
    /// use std::io::prelude::*;
    /// fn list_zip_contents(reader: impl Read + Seek) -> zip::result::ZipResult<()> {
    ///     let mut zip = zip::ZipArchive::new(reader)?;
    ///
    ///     for i in 0..zip.len() {
    ///         let mut file = zip.by_index(i)?;
    ///         println!("Filename: {}", file.name());
    ///         std::io::copy(&mut file, &mut std::io::stdout());
    ///     }
    ///
    ///     Ok(())
    /// }
    /// ```
    #[derive(Clone, Debug)]
    pub struct ZipArchive<R> {
        pub(super) reader: R,
        pub(super) shared: super::Arc<Shared>,
    }
}

pub use zip_archive::ZipArchive;
#[allow(clippy::large_enum_variant)]
enum CryptoReader<'a> {
    Plaintext(io::Take<&'a mut dyn Read>),
    ZipCrypto(ZipCryptoReaderValid<io::Take<&'a mut dyn Read>>),
    #[cfg(feature = "aes-crypto")]
    Aes {
        reader: AesReaderValid<io::Take<&'a mut dyn Read>>,
        vendor_version: AesVendorVersion,
    },
}

impl<'a> Read for CryptoReader<'a> {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        match self {
            CryptoReader::Plaintext(r) => r.read(buf),
            CryptoReader::ZipCrypto(r) => r.read(buf),
            #[cfg(feature = "aes-crypto")]
            CryptoReader::Aes { reader: r, .. } => r.read(buf),
        }
    }
}

impl<'a> CryptoReader<'a> {
    /// Consumes this decoder, returning the underlying reader.
    pub fn into_inner(self) -> io::Take<&'a mut dyn Read> {
        match self {
            CryptoReader::Plaintext(r) => r,
            CryptoReader::ZipCrypto(r) => r.into_inner(),
            #[cfg(feature = "aes-crypto")]
            CryptoReader::Aes { reader: r, .. } => r.into_inner(),
        }
    }

    /// Returns `true` if the data is encrypted using AE2.
    pub fn is_ae2_encrypted(&self) -> bool {
        #[cfg(feature = "aes-crypto")]
        return matches!(
            self,
            CryptoReader::Aes {
                vendor_version: AesVendorVersion::Ae2,
                ..
            }
        );
        #[cfg(not(feature = "aes-crypto"))]
        false
    }
}

enum ZipFileReader<'a> {
    NoReader,
    Raw(io::Take<&'a mut dyn io::Read>),
    Stored(Crc32Reader<CryptoReader<'a>>),
    #[cfg(any(
        feature = "deflate",
        feature = "deflate-miniz",
        feature = "deflate-zlib"
    ))]
    Deflated(Crc32Reader<flate2::read::DeflateDecoder<CryptoReader<'a>>>),
    #[cfg(feature = "bzip2")]
    Bzip2(Crc32Reader<BzDecoder<CryptoReader<'a>>>),
    #[cfg(feature = "zstd")]
    Zstd(Crc32Reader<ZstdDecoder<'a, io::BufReader<CryptoReader<'a>>>>),
}

impl<'a> Read for ZipFileReader<'a> {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        match self {
            ZipFileReader::NoReader => panic!("ZipFileReader was in an invalid state"),
            ZipFileReader::Raw(r) => r.read(buf),
            ZipFileReader::Stored(r) => r.read(buf),
            #[cfg(any(
                feature = "deflate",
                feature = "deflate-miniz",
                feature = "deflate-zlib"
            ))]
            ZipFileReader::Deflated(r) => r.read(buf),
            #[cfg(feature = "bzip2")]
            ZipFileReader::Bzip2(r) => r.read(buf),
            #[cfg(feature = "zstd")]
            ZipFileReader::Zstd(r) => r.read(buf),
        }
    }
}

impl<'a> ZipFileReader<'a> {
    /// Consumes this decoder, returning the underlying reader.
    pub fn into_inner(self) -> io::Take<&'a mut dyn Read> {
        match self {
            ZipFileReader::NoReader => panic!("ZipFileReader was in an invalid state"),
            ZipFileReader::Raw(r) => r,
            ZipFileReader::Stored(r) => r.into_inner().into_inner(),
            #[cfg(any(
                feature = "deflate",
                feature = "deflate-miniz",
                feature = "deflate-zlib"
            ))]
            ZipFileReader::Deflated(r) => r.into_inner().into_inner().into_inner(),
            #[cfg(feature = "bzip2")]
            ZipFileReader::Bzip2(r) => r.into_inner().into_inner().into_inner(),
            #[cfg(feature = "zstd")]
            ZipFileReader::Zstd(r) => r.into_inner().finish().into_inner().into_inner(),
        }
    }
}

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

fn find_content<'a>(
    data: &ZipFileData,
    reader: &'a mut (impl Read + Seek),
) -> ZipResult<io::Take<&'a mut dyn Read>> {
    // Parse local header
    reader.seek(io::SeekFrom::Start(data.header_start))?;
    let signature = reader.read_u32::<LittleEndian>()?;
    if signature != spec::LOCAL_FILE_HEADER_SIGNATURE {
        return Err(ZipError::InvalidArchive("Invalid local file header"));
    }

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

    reader.seek(io::SeekFrom::Start(data_start))?;
    Ok((reader as &mut dyn Read).take(data.compressed_size))
}

#[allow(clippy::too_many_arguments)]
fn make_crypto_reader<'a>(
    compression_method: crate::compression::CompressionMethod,
    crc32: u32,
    last_modified_time: DateTime,
    using_data_descriptor: bool,
    reader: io::Take<&'a mut dyn io::Read>,
    password: Option<&[u8]>,
    aes_info: Option<(AesMode, AesVendorVersion)>,
    #[cfg(feature = "aes-crypto")] compressed_size: u64,
) -> ZipResult<Result<CryptoReader<'a>, InvalidPassword>> {
    #[allow(deprecated)]
    {
        if let CompressionMethod::Unsupported(_) = compression_method {
            return unsupported_zip_error("Compression method not supported");
        }
    }

    let reader = match (password, aes_info) {
        #[cfg(not(feature = "aes-crypto"))]
        (Some(_), Some(_)) => {
            return Err(ZipError::UnsupportedArchive(
                "AES encrypted files cannot be decrypted without the aes-crypto feature.",
            ))
        }
        #[cfg(feature = "aes-crypto")]
        (Some(password), Some((aes_mode, vendor_version))) => {
            match AesReader::new(reader, aes_mode, compressed_size).validate(password)? {
                None => return Ok(Err(InvalidPassword)),
                Some(r) => CryptoReader::Aes {
                    reader: r,
                    vendor_version,
                },
            }
        }
        (Some(password), None) => {
            let validator = if using_data_descriptor {
                ZipCryptoValidator::InfoZipMsdosTime(last_modified_time.timepart())
            } else {
                ZipCryptoValidator::PkzipCrc32(crc32)
            };
            match ZipCryptoReader::new(reader, password).validate(validator)? {
                None => return Ok(Err(InvalidPassword)),
                Some(r) => CryptoReader::ZipCrypto(r),
            }
        }
        (None, Some(_)) => return Ok(Err(InvalidPassword)),
        (None, None) => CryptoReader::Plaintext(reader),
    };
    Ok(Ok(reader))
}

fn make_reader(
    compression_method: CompressionMethod,
    crc32: u32,
    reader: CryptoReader,
) -> ZipFileReader {
    let ae2_encrypted = reader.is_ae2_encrypted();

    match compression_method {
        CompressionMethod::Stored => {
            ZipFileReader::Stored(Crc32Reader::new(reader, crc32, ae2_encrypted))
        }
        #[cfg(any(
            feature = "deflate",
            feature = "deflate-miniz",
            feature = "deflate-zlib"
        ))]
        CompressionMethod::Deflated => {
            let deflate_reader = DeflateDecoder::new(reader);
            ZipFileReader::Deflated(Crc32Reader::new(deflate_reader, crc32, ae2_encrypted))
        }
        #[cfg(feature = "bzip2")]
        CompressionMethod::Bzip2 => {
            let bzip2_reader = BzDecoder::new(reader);
            ZipFileReader::Bzip2(Crc32Reader::new(bzip2_reader, crc32, ae2_encrypted))
        }
        #[cfg(feature = "zstd")]
        CompressionMethod::Zstd => {
            let zstd_reader = ZstdDecoder::new(reader).unwrap();
            ZipFileReader::Zstd(Crc32Reader::new(zstd_reader, crc32, ae2_encrypted))
        }
        _ => panic!("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.
    pub(crate) 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;
                Ok((archive_offset, directory_start, number_of_files))
            }
            Some(locator64) => {
                // If we got here, this is indeed a ZIP64 file.

                if !footer.record_too_small()
                    && 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
                    .checked_add(archive_offset)
                    .ok_or({
                        ZipError::InvalidArchive("Invalid central directory size or offset")
                    })?;

                Ok((
                    archive_offset,
                    directory_start,
                    footer.number_of_files as usize,
                ))
            }
        }
    }

    /// Read a ZIP archive, collecting the files it contains
    ///
    /// This uses the central directory record of the ZIP file, and ignores local file headers
    pub fn new(mut reader: R) -> ZipResult<ZipArchive<R>> {
        let (footer, cde_start_pos) = spec::CentralDirectoryEnd::find_and_parse(&mut reader)?;

        if !footer.record_too_small() && 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)?;

        // If the parsed number of files is greater than the offset then
        // something fishy is going on and we shouldn't trust number_of_files.
        let file_capacity = if number_of_files > cde_start_pos as usize {
            0
        } else {
            number_of_files
        };

        let mut files = Vec::with_capacity(file_capacity);
        let mut names_map = HashMap::with_capacity(file_capacity);

        if reader.seek(io::SeekFrom::Start(directory_start)).is_err() {
            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);
        }

        let shared = Arc::new(zip_archive::Shared {
            files,
            names_map,
            offset: archive_offset,
            comment: footer.zip_file_comment,
        });

        Ok(ZipArchive { reader, shared })
    }
    /// Extract a Zip archive into a directory, overwriting files if they
    /// already exist. Paths are sanitized with [`ZipFile::enclosed_name`].
    ///
    /// Extraction is not atomic; If an error is encountered, some of the files
    /// may be left on disk.
    pub fn extract<P: AsRef<Path>>(&mut self, directory: P) -> ZipResult<()> {
        use std::fs;

        for i in 0..self.len() {
            let mut file = self.by_index(i)?;
            let filepath = file
                .enclosed_name()
                .ok_or(ZipError::InvalidArchive("Invalid file path"))?;

            let outpath = directory.as_ref().join(filepath);

            if file.name().ends_with('/') {
                fs::create_dir_all(&outpath)?;
            } else {
                if let Some(p) = outpath.parent() {
                    if !p.exists() {
                        fs::create_dir_all(p)?;
                    }
                }
                let mut outfile = fs::File::create(&outpath)?;
                io::copy(&mut file, &mut outfile)?;
            }
            // Get and Set permissions
            #[cfg(unix)]
            {
                use std::os::unix::fs::PermissionsExt;
                if let Some(mode) = file.unix_mode() {
                    fs::set_permissions(&outpath, fs::Permissions::from_mode(mode))?;
                }
            }
        }
        Ok(())
    }

    /// Number of files contained in this zip.
    pub fn len(&self) -> usize {
        self.shared.files.len()
    }

    /// Whether this zip archive contains no files
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// 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.shared.offset
    }

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

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

    /// Search for a file entry by name, decrypt with given password
    ///
    /// # Warning
    ///
    /// The implementation of the cryptographic algorithms has not
    /// gone through a correctness review, and you should assume it is insecure:
    /// passwords used with this API may be compromised.
    ///
    /// This function sometimes accepts wrong password. This is because the ZIP spec only allows us
    /// to check for a 1/256 chance that the password is correct.
    /// There are many passwords out there that will also pass the validity checks
    /// we are able to perform. This is a weakness of the ZipCrypto algorithm,
    /// due to its fairly primitive approach to cryptography.
    pub fn by_name_decrypt<'a>(
        &'a mut self,
        name: &str,
        password: &[u8],
    ) -> ZipResult<Result<ZipFile<'a>, InvalidPassword>> {
        self.by_name_with_optional_password(name, Some(password))
    }

    /// Search for a file entry by name
    pub fn by_name<'a>(&'a mut self, name: &str) -> ZipResult<ZipFile<'a>> {
        Ok(self.by_name_with_optional_password(name, None)?.unwrap())
    }

    fn by_name_with_optional_password<'a>(
        &'a mut self,
        name: &str,
        password: Option<&[u8]>,
    ) -> ZipResult<Result<ZipFile<'a>, InvalidPassword>> {
        let index = match self.shared.names_map.get(name) {
            Some(index) => *index,
            None => {
                return Err(ZipError::FileNotFound);
            }
        };
        self.by_index_with_optional_password(index, password)
    }

    /// Get a contained file by index, decrypt with given password
    ///
    /// # Warning
    ///
    /// The implementation of the cryptographic algorithms has not
    /// gone through a correctness review, and you should assume it is insecure:
    /// passwords used with this API may be compromised.
    ///
    /// This function sometimes accepts wrong password. This is because the ZIP spec only allows us
    /// to check for a 1/256 chance that the password is correct.
    /// There are many passwords out there that will also pass the validity checks
    /// we are able to perform. This is a weakness of the ZipCrypto algorithm,
    /// due to its fairly primitive approach to cryptography.
    pub fn by_index_decrypt<'a>(
        &'a mut self,
        file_number: usize,
        password: &[u8],
    ) -> ZipResult<Result<ZipFile<'a>, InvalidPassword>> {
        self.by_index_with_optional_password(file_number, Some(password))
    }

    /// Get a contained file by index
    pub fn by_index(&mut self, file_number: usize) -> ZipResult<ZipFile<'_>> {
        Ok(self
            .by_index_with_optional_password(file_number, None)?
            .unwrap())
    }

    /// Get a contained file by index without decompressing it
    pub fn by_index_raw(&mut self, file_number: usize) -> ZipResult<ZipFile<'_>> {
        let reader = &mut self.reader;
        self.shared
            .files
            .get(file_number)
            .ok_or(ZipError::FileNotFound)
            .and_then(move |data| {
                Ok(ZipFile {
                    crypto_reader: None,
                    reader: ZipFileReader::Raw(find_content(data, reader)?),
                    data: Cow::Borrowed(data),
                })
            })
    }

    fn by_index_with_optional_password<'a>(
        &'a mut self,
        file_number: usize,
        mut password: Option<&[u8]>,
    ) -> ZipResult<Result<ZipFile<'a>, InvalidPassword>> {
        let data = self
            .shared
            .files
            .get(file_number)
            .ok_or(ZipError::FileNotFound)?;

        match (password, data.encrypted) {
            (None, true) => return Err(ZipError::UnsupportedArchive(ZipError::PASSWORD_REQUIRED)),
            (Some(_), false) => password = None, //Password supplied, but none needed! Discard.
            _ => {}
        }
        let limit_reader = find_content(data, &mut self.reader)?;

        match make_crypto_reader(
            data.compression_method,
            data.crc32,
            data.last_modified_time,
            data.using_data_descriptor,
            limit_reader,
            password,
            data.aes_mode,
            #[cfg(feature = "aes-crypto")]
            data.compressed_size,
        ) {
            Ok(Ok(crypto_reader)) => Ok(Ok(ZipFile {
                crypto_reader: Some(crypto_reader),
                reader: ZipFileReader::NoReader,
                data: Cow::Borrowed(data),
            })),
            Err(e) => Err(e),
            Ok(Err(e)) => Ok(Err(e)),
        }
    }

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

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

/// Parse a central directory entry to collect the information for the file.
pub(crate) fn central_header_to_zip_file<R: Read + io::Seek>(
    reader: &mut R,
    archive_offset: u64,
) -> ZipResult<ZipFileData> {
    let central_header_start = reader.stream_position()?;
    // 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 using_data_descriptor = flags & (1 << 3) != 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 mut file_name_raw = vec![0; file_name_length];
    reader.read_exact(&mut file_name_raw)?;
    let mut extra_field = vec![0; extra_field_length];
    reader.read_exact(&mut extra_field)?;
    let mut file_comment_raw = vec![0; file_comment_length];
    reader.read_exact(&mut file_comment_raw)?;

    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,
        using_data_descriptor,
        compression_method: {
            #[allow(deprecated)]
            CompressionMethod::from_u16(compression_method)
        },
        compression_level: None,
        last_modified_time: DateTime::from_msdos(last_mod_date, last_mod_time),
        crc32,
        compressed_size: compressed_size as u64,
        uncompressed_size: uncompressed_size as u64,
        file_name,
        file_name_raw,
        extra_field,
        file_comment,
        header_start: offset,
        central_header_start,
        data_start: AtomicU64::new(0),
        external_attributes: external_file_attributes,
        large_file: false,
        aes_mode: None,
    };

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

    let aes_enabled = result.compression_method == CompressionMethod::AES;
    if aes_enabled && result.aes_mode.is_none() {
        return Err(ZipError::InvalidArchive(
            "AES encryption without AES extra data field",
        ));
    }

    // Account for shifted zip offsets.
    result.header_start = result
        .header_start
        .checked_add(archive_offset)
        .ok_or(ZipError::InvalidArchive("Archive header is too large"))?;

    Ok(result)
}

fn parse_extra_field(file: &mut ZipFileData) -> ZipResult<()> {
    let mut reader = io::Cursor::new(&file.extra_field);

    while (reader.position() as usize) < file.extra_field.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 == spec::ZIP64_BYTES_THR {
                    file.large_file = true;
                    file.uncompressed_size = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
                if file.compressed_size == spec::ZIP64_BYTES_THR {
                    file.large_file = true;
                    file.compressed_size = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
                if file.header_start == spec::ZIP64_BYTES_THR {
                    file.header_start = reader.read_u64::<LittleEndian>()?;
                    len_left -= 8;
                }
            }
            0x9901 => {
                // AES
                if len != 7 {
                    return Err(ZipError::UnsupportedArchive(
                        "AES extra data field has an unsupported length",
                    ));
                }
                let vendor_version = reader.read_u16::<LittleEndian>()?;
                let vendor_id = reader.read_u16::<LittleEndian>()?;
                let aes_mode = reader.read_u8()?;
                let compression_method = reader.read_u16::<LittleEndian>()?;

                if vendor_id != 0x4541 {
                    return Err(ZipError::InvalidArchive("Invalid AES vendor"));
                }
                let vendor_version = match vendor_version {
                    0x0001 => AesVendorVersion::Ae1,
                    0x0002 => AesVendorVersion::Ae2,
                    _ => return Err(ZipError::InvalidArchive("Invalid AES vendor version")),
                };
                match aes_mode {
                    0x01 => file.aes_mode = Some((AesMode::Aes128, vendor_version)),
                    0x02 => file.aes_mode = Some((AesMode::Aes192, vendor_version)),
                    0x03 => file.aes_mode = Some((AesMode::Aes256, vendor_version)),
                    _ => return Err(ZipError::InvalidArchive("Invalid AES encryption strength")),
                };
                file.compression_method = {
                    #[allow(deprecated)]
                    CompressionMethod::from_u16(compression_method)
                };
            }
            _ => {
                // Other fields are ignored
            }
        }

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

/// Methods for retrieving information on zip files
impl<'a> ZipFile<'a> {
    fn get_reader(&mut self) -> &mut ZipFileReader<'a> {
        if let ZipFileReader::NoReader = self.reader {
            let data = &self.data;
            let crypto_reader = self.crypto_reader.take().expect("Invalid reader state");
            self.reader = make_reader(data.compression_method, data.crc32, crypto_reader)
        }
        &mut self.reader
    }

    pub(crate) fn get_raw_reader(&mut self) -> &mut dyn Read {
        if let ZipFileReader::NoReader = self.reader {
            let crypto_reader = self.crypto_reader.take().expect("Invalid reader state");
            self.reader = ZipFileReader::Raw(crypto_reader.into_inner())
        }
        &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
    ///
    /// # Warnings
    ///
    /// It is dangerous to use this name directly when extracting an archive.
    /// It may contain an absolute path (`/etc/shadow`), or break out of the
    /// current directory (`../runtime`). Carelessly writing to these paths
    /// allows an attacker to craft a ZIP archive that will overwrite critical
    /// files.
    ///
    /// You can use the [`ZipFile::enclosed_name`] method to validate the name
    /// as a safe path.
    pub fn name(&self) -> &str {
        &self.data.file_name
    }

    /// Get the name of the file, in the raw (internal) byte representation.
    ///
    /// The encoding of this data is currently undefined.
    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.
    #[deprecated(
        since = "0.5.7",
        note = "by stripping `..`s from the path, the meaning of paths can change.
                `mangled_name` can be used if this behaviour is desirable"
    )]
    pub fn sanitized_name(&self) -> ::std::path::PathBuf {
        self.mangled_name()
    }

    /// Rewrite the path, ignoring any path components with special meaning.
    ///
    /// - Absolute paths are made relative
    /// - [`ParentDir`]s are ignored
    /// - Truncates the filename at a NULL byte
    ///
    /// This is appropriate if you need to be able to extract *something* from
    /// any archive, but will easily misrepresent trivial paths like
    /// `foo/../bar` as `foo/bar` (instead of `bar`). Because of this,
    /// [`ZipFile::enclosed_name`] is the better option in most scenarios.
    ///
    /// [`ParentDir`]: `Component::ParentDir`
    pub fn mangled_name(&self) -> ::std::path::PathBuf {
        self.data.file_name_sanitized()
    }

    /// Ensure the file path is safe to use as a [`Path`].
    ///
    /// - It can't contain NULL bytes
    /// - It can't resolve to a path outside the current directory
    ///   > `foo/../bar` is fine, `foo/../../bar` is not.
    /// - It can't be an absolute path
    ///
    /// This will read well-formed ZIP files correctly, and is resistant
    /// to path-based exploits. It is recommended over
    /// [`ZipFile::mangled_name`].
    pub fn enclosed_name(&self) -> Option<&Path> {
        if self.data.file_name.contains('\0') {
            return None;
        }
        let path = Path::new(&self.data.file_name);
        let mut depth = 0usize;
        for component in path.components() {
            match component {
                Component::Prefix(_) | Component::RootDir => return None,
                Component::ParentDir => depth = depth.checked_sub(1)?,
                Component::Normal(_) => depth += 1,
                Component::CurDir => (),
            }
        }
        Some(path)
    }

    /// 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 bytes, in the archive
    pub fn compressed_size(&self) -> u64 {
        self.data.compressed_size
    }

    /// Get the size of the file, in bytes, 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 MS-DOS 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 extra data of the zip header for this file
    pub fn extra_data(&self) -> &[u8] {
        &self.data.extra_field
    }

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

    /// Get the starting offset of the zip header for this file
    pub fn header_start(&self) -> u64 {
        self.data.header_start
    }
    /// Get the starting offset of the zip header in the central directory for this file
    pub fn central_header_start(&self) -> u64 {
        self.data.central_header_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 decryption, decompression and CRC calculation is skipped.
            let mut reader: std::io::Take<&mut dyn std::io::Read> = match &mut self.reader {
                ZipFileReader::NoReader => {
                    let innerreader = ::std::mem::replace(&mut self.crypto_reader, None);
                    innerreader.expect("Invalid reader state").into_inner()
                }
                reader => {
                    let innerreader = ::std::mem::replace(reader, ZipFileReader::NoReader);
                    innerreader.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;
    #[allow(deprecated)]
    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 mut file_name_raw = vec![0; file_name_length];
    reader.read_exact(&mut file_name_raw)?;
    let mut extra_field = vec![0; extra_field_length];
    reader.read_exact(&mut extra_field)?;

    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,
        using_data_descriptor,
        compression_method,
        compression_level: None,
        last_modified_time: DateTime::from_msdos(last_mod_date, last_mod_time),
        crc32,
        compressed_size: compressed_size as u64,
        uncompressed_size: uncompressed_size as u64,
        file_name,
        file_name_raw,
        extra_field,
        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: AtomicU64::new(0),
        central_header_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,
        large_file: false,
        aes_mode: None,
    };

    match parse_extra_field(&mut result) {
        Ok(..) | Err(ZipError::Io(..)) => {}
        Err(e) => return 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);

    let result_crc32 = result.crc32;
    let result_compression_method = result.compression_method;
    let crypto_reader = make_crypto_reader(
        result_compression_method,
        result_crc32,
        result.last_modified_time,
        result.using_data_descriptor,
        limit_reader,
        None,
        None,
        #[cfg(feature = "aes-crypto")]
        result.compressed_size,
    )?
    .unwrap();

    Ok(Some(ZipFile {
        data: Cow::Owned(result),
        crypto_reader: None,
        reader: make_reader(result_compression_method, result_crc32, crypto_reader),
    }))
}

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

        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 invalid_offset2() {
        use super::ZipArchive;
        use std::io;

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/invalid_offset2.zip"));
        let reader = ZipArchive::new(io::Cursor::new(v));
        assert!(reader.is_err());
    }

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

        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_eq!(reader.len(), 1);
    }

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

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/mimetype.zip"));
        let mut reader = ZipArchive::new(io::Cursor::new(v)).unwrap();
        assert_eq!(reader.comment(), b"");
        assert_eq!(reader.by_index(0).unwrap().central_header_start(), 77);
    }

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

        let mut v = Vec::new();
        v.extend_from_slice(include_bytes!("../tests/data/mimetype.zip"));
        let mut reader = io::Cursor::new(v);
        loop {
            if read_zipfile_from_stream(&mut reader).unwrap().is_none() {
                break;
            }
        }
    }

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

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

        assert_eq!(buf1, buf2);
        assert_eq!(buf3, buf4);
        assert_ne!(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.enclosed_name().unwrap();
            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())
            );
        }
    }

    /// test case to ensure we don't preemptively over allocate based on the
    /// declared number of files in the CDE of an invalid zip when the number of
    /// files declared is more than the alleged offset in the CDE
    #[test]
    fn invalid_cde_number_of_files_allocation_smaller_offset() {
        use super::ZipArchive;
        use std::io;

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

    /// test case to ensure we don't preemptively over allocate based on the
    /// declared number of files in the CDE of an invalid zip when the number of
    /// files declared is less than the alleged offset in the CDE
    #[test]
    fn invalid_cde_number_of_files_allocation_greater_offset() {
        use super::ZipArchive;
        use std::io;

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