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
|
using System;
using System.IO;
using SharpCompress.Common.Zip.Headers;
using SharpCompress.IO;
#if !PORTABLE
using System.Linq;
#endif
namespace SharpCompress.Common.Zip
{
internal class ZipHeaderFactory
{
internal const uint ENTRY_HEADER_BYTES = 0x04034b50;
internal const uint POST_DATA_DESCRIPTOR = 0x08074b50;
internal const uint DIRECTORY_START_HEADER_BYTES = 0x02014b50;
internal const uint DIRECTORY_END_HEADER_BYTES = 0x06054b50;
internal const uint DIGITAL_SIGNATURE = 0x05054b50;
internal const uint SPLIT_ARCHIVE_HEADER_BYTES = 0x30304b50;
private const uint ZIP64_END_OF_CENTRAL_DIRECTORY = 0x06064b50;
private const uint ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR = 0x07064b50;
protected LocalEntryHeader lastEntryHeader;
private string password;
private StreamingMode mode;
protected ZipHeaderFactory(StreamingMode mode, string password)
{
this.mode = mode;
this.password = password;
}
protected ZipHeader ReadHeader(uint headerBytes, BinaryReader reader)
{
switch (headerBytes)
{
case ENTRY_HEADER_BYTES:
{
var entryHeader = new LocalEntryHeader();
entryHeader.Read(reader);
LoadHeader(entryHeader, reader.BaseStream);
lastEntryHeader = entryHeader;
return entryHeader;
}
case DIRECTORY_START_HEADER_BYTES:
{
var entry = new DirectoryEntryHeader();
entry.Read(reader);
return entry;
}
case POST_DATA_DESCRIPTOR:
{
if (FlagUtility.HasFlag(lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
{
lastEntryHeader.Crc = reader.ReadUInt32();
lastEntryHeader.CompressedSize = reader.ReadUInt32();
lastEntryHeader.UncompressedSize = reader.ReadUInt32();
}
else
{
reader.ReadUInt32();
reader.ReadUInt32();
reader.ReadUInt32();
}
return null;
}
case DIGITAL_SIGNATURE:
return null;
case DIRECTORY_END_HEADER_BYTES:
{
var entry = new DirectoryEndHeader();
entry.Read(reader);
return entry;
}
case SPLIT_ARCHIVE_HEADER_BYTES:
{
return new SplitHeader();
}
case ZIP64_END_OF_CENTRAL_DIRECTORY:
case ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR:
{
var entry = new IgnoreHeader(ZipHeaderType.Ignore);
entry.Read(reader);
return entry;
}
default:
throw new NotSupportedException("Unknown header: " + headerBytes);
}
}
internal static bool IsHeader(uint headerBytes)
{
switch (headerBytes)
{
case ENTRY_HEADER_BYTES:
case DIRECTORY_START_HEADER_BYTES:
case POST_DATA_DESCRIPTOR:
case DIGITAL_SIGNATURE:
case DIRECTORY_END_HEADER_BYTES:
case SPLIT_ARCHIVE_HEADER_BYTES:
case ZIP64_END_OF_CENTRAL_DIRECTORY:
case ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR:
return true;
default:
return false;
}
}
private void LoadHeader(ZipFileEntry entryHeader, Stream stream)
{
if (FlagUtility.HasFlag(entryHeader.Flags, HeaderFlags.Encrypted))
{
if (!entryHeader.IsDirectory &&
entryHeader.CompressedSize == 0 &&
FlagUtility.HasFlag(entryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
{
throw new NotSupportedException(
"SharpCompress cannot currently read non-seekable Zip Streams with encrypted data that has been written in a non-seekable manner.");
}
if (password == null)
{
throw new CryptographicException("No password supplied for encrypted zip.");
}
if (entryHeader.CompressionMethod != ZipCompressionMethod.WinzipAes)
{
byte[] buffer = new byte[12];
stream.Read(buffer, 0, 12);
entryHeader.PkwareTraditionalEncryptionData = PkwareTraditionalEncryptionData.ForRead(password,
entryHeader,
buffer);
entryHeader.CompressedSize -= 12;
}
else
{
#if PORTABLE || NETFX_CORE
throw new NotSupportedException("Cannot decrypt Winzip AES with Silverlight or WP7.");
#else
var data = entryHeader.Extra.Where(x => x.Type == ExtraDataType.WinZipAes).SingleOrDefault();
WinzipAesKeySize keySize = (WinzipAesKeySize) data.DataBytes[4];
byte[] salt = new byte[WinzipAesEncryptionData.KeyLengthInBytes(keySize)/2];
byte[] passwordVerifyValue = new byte[2];
stream.Read(salt, 0, salt.Length);
stream.Read(passwordVerifyValue, 0, 2);
entryHeader.WinzipAesEncryptionData = new WinzipAesEncryptionData(keySize, salt, passwordVerifyValue,
password);
entryHeader.CompressedSize -= (uint) (salt.Length + 2);
#endif
}
}
if (entryHeader.IsDirectory)
{
return;
}
//if (FlagUtility.HasFlag(entryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
//{
// entryHeader.PackedStream = new ReadOnlySubStream(stream);
//}
//else
//{
switch (mode)
{
case StreamingMode.Seekable:
{
entryHeader.DataStartPosition = stream.Position;
stream.Position += entryHeader.CompressedSize;
}
break;
case StreamingMode.Streaming:
{
entryHeader.PackedStream = stream;
}
break;
default:
{
throw new InvalidFormatException("Invalid StreamingMode");
}
}
//}
}
}
}
|
