File size: 2,288 Bytes
18a519f | 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 | /*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
using System;
using System.IO;
namespace Microsoft.Unity.VisualStudio.Editor
{
public sealed class Image : IDisposable
{
long position;
Stream stream;
Image(Stream stream)
{
this.stream = stream;
this.position = stream.Position;
this.stream.Position = 0;
}
bool Advance(int length)
{
if (stream.Position + length >= stream.Length)
return false;
stream.Seek(length, SeekOrigin.Current);
return true;
}
bool MoveTo(uint position)
{
if (position >= stream.Length)
return false;
stream.Position = position;
return true;
}
void IDisposable.Dispose()
{
stream.Position = position;
}
ushort ReadUInt16()
{
return (ushort)(stream.ReadByte()
| (stream.ReadByte() << 8));
}
uint ReadUInt32()
{
return (uint)(stream.ReadByte()
| (stream.ReadByte() << 8)
| (stream.ReadByte() << 16)
| (stream.ReadByte() << 24));
}
bool IsManagedAssembly()
{
if (stream.Length < 318)
return false;
if (ReadUInt16() != 0x5a4d)
return false;
if (!Advance(58))
return false;
if (!MoveTo(ReadUInt32()))
return false;
if (ReadUInt32() != 0x00004550)
return false;
if (!Advance(20))
return false;
if (!Advance(ReadUInt16() == 0x20b ? 222 : 206))
return false;
return ReadUInt32() != 0;
}
public static bool IsAssembly(string file)
{
if (file == null)
throw new ArgumentNullException("file");
using (var stream = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.Read))
return IsAssembly(stream);
}
public static bool IsAssembly(Stream stream)
{
if (stream == null)
throw new ArgumentNullException(nameof(stream));
if (!stream.CanRead)
throw new ArgumentException(nameof(stream));
if (!stream.CanSeek)
throw new ArgumentException(nameof(stream));
using (var image = new Image(stream))
return image.IsManagedAssembly();
}
}
}
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