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//------------------------------------------------------------------------------
// Microsoft Avalon
// Copyright (c) Microsoft Corporation, 2003
//
// File: BitmapDecoder.cs
//
//------------------------------------------------------------------------------
#pragma warning disable 1634, 1691 // Allow suppression of certain presharp messages
using System;
using System.IO;
using System.IO.Packaging;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Collections.ObjectModel;
using System.Reflection;
using System.Security;
using System.Security.Permissions;
using System.Text.RegularExpressions;
using MS.Internal;
using MS.Internal.AppModel;
using MS.Win32.PresentationCore;
using Microsoft.Win32.SafeHandles;
using System.Diagnostics;
using System.Windows.Media;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Threading;
using System.Windows.Media.Imaging;
using MS.Internal.PresentationCore; // SecurityHelper
using SR=MS.Internal.PresentationCore.SR;
using SRID=MS.Internal.PresentationCore.SRID;
using System.Net;
using System.Net.Cache;
using System.Text;
namespace System.Windows.Media.Imaging
{
#region BitmapDecoder
/// <summary>
/// BitmapDecoder is a container for bitmap frames. Each bitmap frame is an BitmapFrame.
/// Any BitmapFrame it returns are frozen
/// be immutable.
/// </summary>
public abstract class BitmapDecoder : DispatcherObject
{
#region Constructors
/// <SecurityNote>
/// Critical: This code has critical static variables isImageDisabledInitialized
/// TreatAsASafe: The variables are not exposed
/// </SecurityNote>
[SecurityCritical,SecurityTreatAsSafe]
static BitmapDecoder()
{
isImageDisabledInitialized = false;
}
/// <summary>
/// Default constructor
/// </summary>
protected BitmapDecoder()
{
}
/// <summary>
/// Internal constructor
/// </summary>
internal BitmapDecoder(bool isBuiltIn)
{
_isBuiltInDecoder = isBuiltIn;
}
/// <summary>
/// Constructor
/// </summary>
/// <SecurityNote>
/// Critical - access critical resource
/// </SecurityNote>
[SecurityCritical]
internal BitmapDecoder(
Uri bitmapUri,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption,
Guid expectedClsId
)
{
Guid clsId = Guid.Empty;
bool isOriginalWritable = false;
if (bitmapUri == null)
{
throw new ArgumentNullException("bitmapUri");
}
if ((createOptions & BitmapCreateOptions.IgnoreImageCache) != 0)
{
ImagingCache.RemoveFromDecoderCache(bitmapUri);
}
BitmapDecoder decoder = CheckCache(bitmapUri, out clsId);
if (decoder != null)
{
_decoderHandle = decoder.InternalDecoder;
}
else
{
_decoderHandle = SetupDecoderFromUriOrStream(
bitmapUri,
null,
cacheOption,
out clsId,
out isOriginalWritable,
out _uriStream,
out _unmanagedMemoryStream,
out _safeFilehandle
);
if (_uriStream == null)
{
GC.SuppressFinalize(this);
}
}
if (clsId != expectedClsId)
{
throw new FileFormatException(bitmapUri, SR.Get(SRID.Image_CantDealWithUri));
}
_uri = bitmapUri;
_createOptions = createOptions;
_cacheOption = cacheOption;
_syncObject = _decoderHandle;
_isOriginalWritable = isOriginalWritable;
Initialize(decoder);
}
/// <summary>
/// Constructor
/// </summary>
/// <SecurityNote>
/// Critical - access critical resource
/// </SecurityNote>
[SecurityCritical]
internal BitmapDecoder(
Stream bitmapStream,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption,
Guid expectedClsId
)
{
Guid clsId = Guid.Empty;
bool isOriginalWritable = false;
if (bitmapStream == null)
{
throw new ArgumentNullException("bitmapStream");
}
_decoderHandle = SetupDecoderFromUriOrStream(
null,
bitmapStream,
cacheOption,
out clsId,
out isOriginalWritable,
out _uriStream,
out _unmanagedMemoryStream,
out _safeFilehandle
);
if (_uriStream == null)
{
GC.SuppressFinalize(this);
}
if (clsId != Guid.Empty && clsId != expectedClsId)
{
throw new FileFormatException(null, SR.Get(SRID.Image_CantDealWithStream));
}
_stream = bitmapStream;
_createOptions = createOptions;
_cacheOption = cacheOption;
_syncObject = _decoderHandle;
_isOriginalWritable = isOriginalWritable;
Initialize(null);
}
/// <summary>
/// Constructor
/// </summary>
/// <SecurityNote>
/// Critical: strictly speaking because the method uses a SafeFileHandle, which is a SecurityCritical
/// type (in v4). But it also takes other resources as input that untrusted code shouldn't have
/// access to (SafeMILHandle, UnmanagedMemoryStream).
/// </SecurityNote>
[SecurityCritical]
internal BitmapDecoder(
SafeMILHandle decoderHandle,
BitmapDecoder decoder,
Uri baseUri,
Uri uri,
Stream stream,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption,
bool insertInDecoderCache,
bool isOriginalWritable,
Stream uriStream,
UnmanagedMemoryStream unmanagedMemoryStream,
SafeFileHandle safeFilehandle
)
{
_decoderHandle = decoderHandle;
_baseUri = baseUri;
_uri = uri;
_stream = stream;
_createOptions = createOptions;
_cacheOption = cacheOption;
_syncObject = decoderHandle;
_shouldCacheDecoder = insertInDecoderCache;
_isOriginalWritable = isOriginalWritable;
_uriStream = uriStream;
_unmanagedMemoryStream = unmanagedMemoryStream;
_safeFilehandle = safeFilehandle;
if (_uriStream == null)
{
GC.SuppressFinalize(this);
}
Initialize(decoder);
}
/// <summary>
/// Close the stream pointing to the file after this BitmapDecoder is no longer used.
/// It might have been closed before in Initialize if the cache option was OnLoad or
/// on decode if the cache option was OnDemand/Default. In those cases, the finalizer
/// would have been suppressed.
/// </summary>
/// <SecurityNote>
/// Critical - accesses critical resource _uriStream
/// TreatAsSafe - doesn't return the uriStream, just closes it which is safe
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
~BitmapDecoder()
{
//
// Normally _uriStream gets GCed because this BitmapDecoder is the only thing that
// references it, and the stream's finalizer closes it. However, in some cases, other
// objects still have references to the _uriStream, so it won't get GCed because this
// decoder does. One such case is getting the stream from a pack uri that points to
// a resource. In those cases, PackagePart created the streams and is also holding on
// to them. It won't let go unless the stream is closed, but the stream won't close
// unless it's been let go, so the stream is leaked. Closing the stream removes the
// leak.
//
// _uriStream is always created within SetupDecoderFromUriOrStream. Either it's set
// using an out parameter, or it's set in the internal constructor that takes a
// uriStream parameter. That internal constructor is called by the sealed subclasses
// of BitmapDecoder (such as JpegBitmapDecoder), those subclasses are constructed in
// CreateFromUriOrStream, which also gets uriStream from SetupDecoderFromUriOrStream.
//
if (_uriStream != null)
{
_uriStream.Close();
}
}
/// <summary>
/// Create BitmapDecoder from the uri or stream. If both are specified, the uri
/// is chosen.
/// </summary>
/// <SecurityNote>
/// Critical - Unmanaged code will eventually create a COM object, need to secure it
/// Calls one of the XxxBitmapDecoder static internal ctors, which are all SecurityCritical.
/// TreatAsSafe - All inputs verified
/// The inputs of unsafe types that are passed to XxxBitmapDecoder are produced within this method,
/// not taken from outside.
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
internal static BitmapDecoder CreateFromUriOrStream(
Uri baseUri,
Uri uri,
Stream stream,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption,
RequestCachePolicy uriCachePolicy,
bool insertInDecoderCache
)
{
Guid clsId = Guid.Empty;
bool isOriginalWritable = false;
SafeMILHandle decoderHandle = null;
BitmapDecoder cachedDecoder = null;
Uri finalUri = null;
Stream uriStream = null;
UnmanagedMemoryStream unmanagedMemoryStream = null;
SafeFileHandle safeFilehandle = null;
// check to ensure that images are allowed in partial trust
DemandIfImageBlocked();
if (uri != null)
{
finalUri = (baseUri != null) ?
System.Windows.Navigation.BaseUriHelper.GetResolvedUri(baseUri, uri) :
uri;
if (insertInDecoderCache)
{
if ((createOptions & BitmapCreateOptions.IgnoreImageCache) != 0)
{
ImagingCache.RemoveFromDecoderCache(finalUri);
}
cachedDecoder = CheckCache(
finalUri,
out clsId
);
}
}
// try to retrieve the cached decoder
if (cachedDecoder != null)
{
decoderHandle = cachedDecoder.InternalDecoder;
}
else if ((finalUri != null) && (finalUri.IsAbsoluteUri) && (stream == null) &&
((finalUri.Scheme == Uri.UriSchemeHttp) ||
(finalUri.Scheme == Uri.UriSchemeHttps)))
{
return new LateBoundBitmapDecoder(baseUri, uri, stream, createOptions, cacheOption, uriCachePolicy);
}
else if ((stream != null) && (!stream.CanSeek))
{
return new LateBoundBitmapDecoder(baseUri, uri, stream, createOptions, cacheOption, uriCachePolicy);
}
else
{
// Create an unmanaged decoder
decoderHandle = BitmapDecoder.SetupDecoderFromUriOrStream(
finalUri,
stream,
cacheOption,
out clsId,
out isOriginalWritable,
out uriStream,
out unmanagedMemoryStream,
out safeFilehandle
);
}
BitmapDecoder decoder = null;
// Find out the decoder type and wrap it appropriately and return that
if (MILGuidData.GUID_ContainerFormatBmp == clsId)
{
decoder = new BmpBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatGif == clsId)
{
decoder = new GifBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatIco == clsId)
{
decoder = new IconBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatJpeg == clsId)
{
decoder = new JpegBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatPng == clsId)
{
decoder = new PngBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatTiff == clsId)
{
decoder = new TiffBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else if (MILGuidData.GUID_ContainerFormatWmp == clsId)
{
decoder = new WmpBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
else
{
decoder = new UnknownBitmapDecoder(
decoderHandle,
cachedDecoder,
baseUri,
uri,
stream,
createOptions,
cacheOption,
insertInDecoderCache,
isOriginalWritable,
uriStream,
unmanagedMemoryStream,
safeFilehandle
);
}
return decoder;
}
/// <summary>
/// Create a BitmapDecoder from a Uri with the specified BitmapCreateOptions and
/// BitmapCacheOption
/// </summary>
/// <param name="bitmapUri">Uri to decode</param>
/// <param name="createOptions">Bitmap Create Options</param>
/// <param name="cacheOption">Bitmap Caching Option</param>
public static BitmapDecoder Create(
Uri bitmapUri,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption
)
{
return Create(bitmapUri, createOptions, cacheOption, null);
}
/// <summary>
/// Create a BitmapDecoder from a Uri with the specified BitmapCreateOptions and
/// BitmapCacheOption
/// </summary>
/// <param name="bitmapUri">Uri to decode</param>
/// <param name="createOptions">Bitmap Create Options</param>
/// <param name="cacheOption">Bitmap Caching Option</param>
/// <param name="uriCachePolicy">Optional web request cache policy</param>
public static BitmapDecoder Create(
Uri bitmapUri,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption,
RequestCachePolicy uriCachePolicy
)
{
if (bitmapUri == null)
{
throw new ArgumentNullException("bitmapUri");
}
return CreateFromUriOrStream(
null,
bitmapUri,
null,
createOptions,
cacheOption,
uriCachePolicy,
true
);
}
/// <summary>
/// Create a BitmapDecoder from a Stream with the specified BitmapCreateOptions and
/// BitmapCacheOption
/// </summary>
/// <param name="bitmapStream">Stream to decode</param>
/// <param name="createOptions">Bitmap Create Options</param>
/// <param name="cacheOption">Bitmap Caching Option</param>
public static BitmapDecoder Create(
Stream bitmapStream,
BitmapCreateOptions createOptions,
BitmapCacheOption cacheOption
)
{
if (bitmapStream == null)
{
throw new ArgumentNullException("bitmapStream");
}
return CreateFromUriOrStream(
null,
null,
bitmapStream,
createOptions,
cacheOption,
null,
true
);
}
#endregion
#region Properties
/// <summary>
/// If there is an palette, return it.
/// Otherwise, return null.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// PublicOK - Getting palette data is OK
/// </SecurityNote>
public virtual BitmapPalette Palette
{
[SecurityCritical]
get
{
VerifyAccess();
EnsureBuiltInDecoder();
if (!_isPaletteCached)
{
SafeMILHandle /* IWICBitmapPalette */ paletteHandle = BitmapPalette.CreateInternalPalette();
lock (_syncObject)
{
int hr = UnsafeNativeMethods.WICBitmapDecoder.CopyPalette(
_decoderHandle,
paletteHandle
);
if (hr != (int)WinCodecErrors.WINCODEC_ERR_PALETTEUNAVAILABLE)
{
HRESULT.Check(hr);
_palette = new BitmapPalette(paletteHandle);
}
}
_isPaletteCached = true;
}
return _palette;
}
}
/// <summary>
/// If there is an embedded color profile, return it.
/// Otherwise, return null.
/// </summary>
public virtual ReadOnlyCollection<ColorContext> ColorContexts
{
get
{
VerifyAccess();
return InternalColorContexts;
}
}
/// <summary>
/// If there is a global thumbnail, return it.
/// Otherwise, return null. The returned source is frozen.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// PublicOK - Getting thumbnail data is OK
/// </SecurityNote>
public virtual BitmapSource Thumbnail
{
[SecurityCritical ]
get
{
VerifyAccess();
EnsureBuiltInDecoder();
if (!_isThumbnailCached)
{
IntPtr /* IWICBitmapSource */ thumbnail = IntPtr.Zero;
// Check if there is embedded thumbnail or not
lock (_syncObject)
{
int hr = UnsafeNativeMethods.WICBitmapDecoder.GetThumbnail(
_decoderHandle,
out thumbnail
);
if (hr != (int)WinCodecErrors.WINCODEC_ERR_CODECNOTHUMBNAIL)
{
HRESULT.Check(hr);
}
}
if (thumbnail != IntPtr.Zero)
{
BitmapSourceSafeMILHandle thumbHandle = new BitmapSourceSafeMILHandle(thumbnail);
SafeMILHandle unmanagedPalette = BitmapPalette.CreateInternalPalette();
BitmapPalette palette = null;
int hr = UnsafeNativeMethods.WICBitmapSource.CopyPalette(
thumbHandle,
unmanagedPalette
);
if (hr == HRESULT.S_OK)
{
palette = new BitmapPalette(unmanagedPalette);
}
_thumbnail = new UnmanagedBitmapWrapper(
BitmapSource.CreateCachedBitmap(
null,
thumbHandle,
BitmapCreateOptions.PreservePixelFormat,
_cacheOption,
palette
));
_thumbnail.Freeze();
}
_isThumbnailCached = true;
}
return _thumbnail;
}
}
/// <summary>
/// If there is a global metadata, return it.
/// Otherwise, return null. The returned source is frozen.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// Public -
/// Getting metadata for images from site of origin or bundled with the application is OK
/// Getting metatdat for images from cross domain servers triggers a demand for site of origin.
/// </SecurityNote>
public virtual BitmapMetadata Metadata
{
[SecurityCritical]
get
{
VerifyAccess();
EnsureBuiltInDecoder();
// Demand Site Of origin on the URI if it passes then this information is ok to expose
CheckIfSiteOfOrigin();
if (!_isMetadataCached)
{
IntPtr /* IWICMetadataQueryReader */ metadata = IntPtr.Zero;
lock (_syncObject)
{
int hr = UnsafeNativeMethods.WICBitmapDecoder.GetMetadataQueryReader(
_decoderHandle,
out metadata
);
if (hr != (int)WinCodecErrors.WINCODEC_ERR_UNSUPPORTEDOPERATION)
{
HRESULT.Check(hr);
}
}
if (metadata != IntPtr.Zero)
{
SafeMILHandle metadataHandle = new SafeMILHandle(metadata);
_metadata = new BitmapMetadata(metadataHandle, true, IsMetadataFixedSize, _syncObject);
_metadata.Freeze();
}
_isMetadataCached = true;
}
return _metadata;
}
}
/// <summary>
/// The info that identifies this codec.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// PublicOK - Getting codecinfo data is OK
/// </SecurityNote>
public virtual BitmapCodecInfo CodecInfo
{
[SecurityCritical]
get
{
VerifyAccess();
EnsureBuiltInDecoder();
// There should always be a codec info.
if (_codecInfo == null)
{
SafeMILHandle /* IWICBitmapDecoderInfo */ codecInfoHandle = new SafeMILHandle();
HRESULT.Check(UnsafeNativeMethods.WICBitmapDecoder.GetDecoderInfo(
_decoderHandle,
out codecInfoHandle
));
_codecInfo = new BitmapCodecInfoInternal(codecInfoHandle);
}
return _codecInfo;
}
}
/// <summary>
/// Access to the individual frames. All BitmapFrames are frozen.
/// </summary>
public virtual ReadOnlyCollection<BitmapFrame> Frames
{
get
{
VerifyAccess();
EnsureBuiltInDecoder();
if (_frames == null)
{
SetupFrames(null, null);
}
if (_readOnlyFrames == null)
{
_readOnlyFrames = new ReadOnlyCollection<BitmapFrame>(_frames);
}
return _readOnlyFrames;
}
}
/// <summary>
/// If there is a global preview image, return it.
/// Otherwise, return null. The returned source is frozen.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// PublicOK - Getting preview data is OK
/// </SecurityNote>
public virtual BitmapSource Preview
{
[SecurityCritical]
get
{
VerifyAccess();
EnsureBuiltInDecoder();
if (!_isPreviewCached)
{
IntPtr /* IWICBitmapSource */ preview = IntPtr.Zero;
lock (_syncObject)
{
// Check if there is embedded preview or not
int hr = UnsafeNativeMethods.WICBitmapDecoder.GetPreview(
_decoderHandle,
out preview
);
if (hr != (int)WinCodecErrors.WINCODEC_ERR_UNSUPPORTEDOPERATION)
{
HRESULT.Check(hr);
}
}
if (preview != IntPtr.Zero)
{
BitmapSourceSafeMILHandle previewHandle = new BitmapSourceSafeMILHandle(preview);
SafeMILHandle unmanagedPalette = BitmapPalette.CreateInternalPalette();
BitmapPalette palette = null;
int hr = UnsafeNativeMethods.WICBitmapSource.CopyPalette(
previewHandle,
unmanagedPalette
);
if (hr == HRESULT.S_OK)
{
palette = new BitmapPalette(unmanagedPalette);
}
_preview = new UnmanagedBitmapWrapper(
BitmapSource.CreateCachedBitmap(
null,
previewHandle,
BitmapCreateOptions.PreservePixelFormat,
_cacheOption,
palette
));
_preview.Freeze();
}
_isPreviewCached = true;
}
return _preview;
}
}
/// <summary>
/// Returns true if the decoder is downloading content
/// </summary>
public virtual bool IsDownloading
{
get
{
VerifyAccess();
EnsureBuiltInDecoder();
return false;
}
}
/// <summary>
/// Raised when decoder has completed downloading content
/// May not be raised for all content.
/// </summary>
public virtual event EventHandler DownloadCompleted
{
add
{
VerifyAccess();
EnsureBuiltInDecoder();
_downloadEvent.AddEvent(value);
}
remove
{
VerifyAccess();
EnsureBuiltInDecoder();
_downloadEvent.RemoveEvent(value);
}
}
/// <summary>
/// Raised when download has progressed
/// May not be raised for all content.
/// </summary>
public virtual event EventHandler<DownloadProgressEventArgs> DownloadProgress
{
add
{
VerifyAccess();
EnsureBuiltInDecoder();
_progressEvent.AddEvent(value);
}
remove
{
VerifyAccess();
EnsureBuiltInDecoder();
_progressEvent.RemoveEvent(value);
}
}
/// <summary>
/// Raised when download has failed
/// May not be raised for all content.
/// </summary>
public virtual event EventHandler<ExceptionEventArgs> DownloadFailed
{
add
{
VerifyAccess();
EnsureBuiltInDecoder();
_failedEvent.AddEvent(value);
}
remove
{
VerifyAccess();
EnsureBuiltInDecoder();
_failedEvent.RemoveEvent(value);
}
}
#endregion
#region Public Properties
/// <summary>
/// Create an in-place bitmap metadata writer.
/// </summary>
public virtual InPlaceBitmapMetadataWriter CreateInPlaceBitmapMetadataWriter()
{
VerifyAccess();
EnsureBuiltInDecoder();
CheckOriginalWritable();
// Demand Site Of origin on the URI if it passes then this information is ok to expose
CheckIfSiteOfOrigin();
return InPlaceBitmapMetadataWriter.CreateFromDecoder(_decoderHandle, _syncObject);
}
#endregion
#region ToString
/// <summary>
/// ToString
/// </summary>
public override string ToString()
{
VerifyAccess();
if (!_isBuiltInDecoder)
{
return base.ToString();
}
if (_uri != null)
{
if (_baseUri != null)
{
Uri uri = new Uri(_baseUri, _uri);
return BindUriHelper.UriToString(uri);
}
else
{
return BindUriHelper.UriToString(_uri);
}
}
else
{
return SafeSecurityHelper.IMAGE;
}
}
#endregion
#region Internal Properties
/// <summary>
/// Internal Decoder
/// </summary>
internal SafeMILHandle InternalDecoder
{
get
{
return _decoderHandle;
}
}
/// <summary>
/// Returns whether metadata is fixed size or not.
/// </summary>
internal virtual bool IsMetadataFixedSize
{
get
{
return false;
}
}
/// <summary>
/// Synchronization Object. Any unmanaged PInvoke/call that requires synchronization
/// must lock on the sync object. This object must be internal or private so as not
/// to be publicly lockable.
/// </summary>
internal object SyncObject
{
get
{
Debug.Assert(_syncObject != null);
return _syncObject;
}
}
/// <summary>
/// Used as a delegate in InternalColorContexts to get the unmanaged IWICColorContexts
/// </summary>
/// <SecurityNote>
/// Critical - Calls critical, unmanaged method
/// </SecurityNote>
[SecurityCritical]
private int GetColorContexts(ref uint numContexts, IntPtr[] colorContextPtrs)
{
Invariant.Assert(colorContextPtrs == null || numContexts <= colorContextPtrs.Length);
return UnsafeNativeMethods.WICBitmapDecoder.GetColorContexts(_decoderHandle, numContexts, colorContextPtrs, out numContexts);
}
/// <summary>
/// If there is an embedded color profile, return it.
/// Otherwise, return null.
/// </summary>
/// <SecurityNote>
/// Critical - Access unmanaged code, codecs
/// TreatAsSafe - We are exposing specific, non-sensitive data that came from
/// a Uri or a bitmap. If the profile data came from a Uri, the
/// WebRequest we did to get it demandend the appropriate
/// permission and we did not expose the request or response. If it came
/// from a bitmap, it may be cross-domain, but the restricted
/// nature of the data combined with the fact that it has been
/// inspected by WCS which is hardened against malicious data
/// makes this OK.
/// </SecurityNote>
internal ReadOnlyCollection<ColorContext> InternalColorContexts
{
[SecurityCritical, SecurityTreatAsSafe]
get
{
EnsureBuiltInDecoder();
if (!_isColorContextCached)
{
lock (_syncObject)
{
IList<ColorContext> colorContextList = ColorContext.GetColorContextsHelper(GetColorContexts);
if (colorContextList != null)
{
_readOnlycolorContexts = new ReadOnlyCollection<ColorContext>(colorContextList);
}
_isColorContextCached = true;
}
}
return _readOnlycolorContexts;
}
}
/// <summary>
/// Checks whether the underlying source is writable (useful for in-place metadata editing)
/// </summary>
internal void CheckOriginalWritable()
{
if (!_isOriginalWritable)
{
throw new System.InvalidOperationException(SR.Get(SRID.Image_OriginalStreamReadOnly));
}
}
#endregion
#region Internal/Private Methods
/// <SecurityNote>
/// Critical: This sets and accesses critical members isImageDisabledInitialized,isImageDisabled
/// TreatAsSafe: This code does not expose the variables and is not influenced by external paramaters that do not
/// require unmanaged code access permission to set
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
private static void DemandIfImageBlocked()
{
if(!isImageDisabledInitialized)
{
// a performance optimization to ensure we hit the registry only once in the lifetime of the application
isImageDisabled = new SecurityCriticalDataForSet<bool>(SafeSecurityHelper.IsFeatureDisabled(SafeSecurityHelper.KeyToRead.MediaImageDisable));
isImageDisabledInitialized = true;
}
if (isImageDisabled.Value)
{
// in case the registry key is '1' then demand MediaPermissionImage.AllImage - not granted in Partial Trust
SecurityHelper.DemandMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.AllImage);
}
else
{
// Images are enabled. Then, demand permissions for safe imaging - granted in Partial Trust by default
SecurityHelper.DemandMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.SafeImage);
}
}
/// <SecurityNote>
/// Critical - Unmanaged code will eventually create a COM object, need to secure it
/// </SecurityNote>
[SecurityCritical]
internal static SafeMILHandle SetupDecoderFromUriOrStream(
Uri uri,
Stream stream,
BitmapCacheOption cacheOption,
out Guid clsId,
out bool isOriginalWritable,
out Stream uriStream,
out UnmanagedMemoryStream unmanagedMemoryStream,
out SafeFileHandle safeFilehandle
)
{
SafeMILHandle decoderHandle;
IntPtr decoder = IntPtr.Zero;
System.IO.Stream bitmapStream = null;
string mimeType = String.Empty;
// check to ensure that images are allowed in partial trust NOP in full trust
DemandIfImageBlocked();
unmanagedMemoryStream = null;
safeFilehandle = null;
isOriginalWritable = false;
uriStream = null;
if ((uri != null) && (stream != null))
{
// In this case we expect the Uri to be http(s)
Debug.Assert((uri.Scheme == Uri.UriSchemeHttp) || (uri.Scheme == Uri.UriSchemeHttps));
Debug.Assert(stream.CanSeek);
}
// Uri
if (uri != null)
{
if (uri.IsAbsoluteUri)
{
// In this case we first check to see if the consumer has media permissions for
// safe media (Site of Origin + Cross domain)
SecurityHelper.DemandMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.SiteOfOriginImage) ;
// This code path executes only for pack web requests
if (String.Compare(uri.Scheme, PackUriHelper.UriSchemePack, StringComparison.OrdinalIgnoreCase) == 0)
{
WebResponse response = WpfWebRequestHelper.CreateRequestAndGetResponse(uri);
mimeType = response.ContentType;
bitmapStream = response.GetResponseStream();
uriStream = bitmapStream;
}
}
if ((bitmapStream == null) || (bitmapStream == System.IO.Stream.Null))
{
// We didn't get a stream from the pack web request, so we have
// to try to create one ourselves.
if (uri.IsAbsoluteUri)
{
// The Uri class can't tell if it is a file unless it
// has an absolute path.
int targetZone = SecurityHelper.MapUrlToZoneWrapper(uri);
if (targetZone == MS.Win32.NativeMethods.URLZONE_LOCAL_MACHINE)
{
if (uri.IsFile)
{
// FileStream does a demand for us, so no need to do a demand
bitmapStream = new System.IO.FileStream(uri.LocalPath, FileMode.Open, FileAccess.Read, FileShare.Read);
}
}
else // Any other zone
{
// UNC path for a file which is not http
if (uri.IsFile && uri.IsUnc) // for UNC
{
bitmapStream = ProcessUncFiles(uri);
}
else if (uri.Scheme == Uri.UriSchemeHttp) // for http
{
bitmapStream = ProcessHttpFiles(uri,stream);
}
else if (uri.Scheme == Uri.UriSchemeHttps) // for https
{
bitmapStream = ProcessHttpsFiles(uri,stream);
}
else
{
// The Uri is a custom Uri. Try to grab the stream from its WebResponse.
bitmapStream = WpfWebRequestHelper.CreateRequestAndGetResponseStream(uri);
}
}
}
else
{
#pragma warning disable 6518
// We don't have an absolute URI, so we don't necessarily know
// if it is a file, but we'll have to assume it is and try to
// create a stream from the original string.
bitmapStream = new System.IO.FileStream(uri.OriginalString, FileMode.Open, FileAccess.Read, FileShare.Read);
#pragma warning restore 6518
}
uriStream = bitmapStream;
}
}
// We need to use the stream created from the Uri.
if (bitmapStream != null)
{
stream = bitmapStream;
}
else
{
// Note whether the original stream is writable.
isOriginalWritable = stream.CanSeek && stream.CanWrite;
}
// Make sure we always use a seekable stream to avoid problems with http Uris etc.
stream = GetSeekableStream(stream);
if (stream is UnmanagedMemoryStream)
{
unmanagedMemoryStream = stream as UnmanagedMemoryStream;
}
IntPtr comStream = IntPtr.Zero;
if (stream is System.IO.FileStream)
{
System.IO.FileStream filestream = stream as System.IO.FileStream;
try
{
safeFilehandle = filestream.SafeFileHandle;
}
catch
{
// If Filestream doesn't support SafeHandle then revert to old code path.
safeFilehandle = null;
}
}
try
{
Guid vendorMicrosoft = new Guid(MILGuidData.GUID_VendorMicrosoft);
UInt32 metadataFlags = (uint)WICMetadataCacheOptions.WICMetadataCacheOnDemand;
if (cacheOption == BitmapCacheOption.OnLoad)
{
metadataFlags = (uint)WICMetadataCacheOptions.WICMetadataCacheOnLoad;
}
// We have a SafeHandle.
if (safeFilehandle != null)
{
using (FactoryMaker myFactory = new FactoryMaker())
{
HRESULT.Check(UnsafeNativeMethods.WICImagingFactory.CreateDecoderFromFileHandle(
myFactory.ImagingFactoryPtr,
safeFilehandle,
ref vendorMicrosoft,
metadataFlags,
out decoder
));
}
}
else
{
comStream = BitmapDecoder.GetIStreamFromStream(ref stream);
using (FactoryMaker myFactory = new FactoryMaker())
{
// This does an add-ref on the comStream
HRESULT.Check(UnsafeNativeMethods.WICImagingFactory.CreateDecoderFromStream(
myFactory.ImagingFactoryPtr,
comStream,
ref vendorMicrosoft,
metadataFlags,
out decoder
));
}
}
Debug.Assert(decoder != IntPtr.Zero);
decoderHandle = new SafeMILHandle(decoder);
}
catch
{
#pragma warning disable 6500
decoderHandle = null;
throw;
#pragma warning restore 6500
}
finally
{
UnsafeNativeMethods.MILUnknown.ReleaseInterface(ref comStream);
}
string decoderMimeTypes;
clsId = GetCLSIDFromDecoder(decoderHandle, out decoderMimeTypes);
// If the mime type of the file does not match the associated decoder,
// and if we are in a Partial trust scenario, throw!
if ((mimeType != String.Empty) &&
(decoderMimeTypes.IndexOf(mimeType, StringComparison.OrdinalIgnoreCase) == -1))
{
try
{
SecurityHelper.DemandUnmanagedCode();
}
catch(SecurityException)
{
throw new ArgumentException(SR.Get(SRID.Image_ContentTypeDoesNotMatchDecoder));
}
}
return decoderHandle;
}
/// <SecurityNote>
/// Critical: performs an assert for WebPermission potentially outside the site of origin.
/// </SecurityNote>
[SecurityCritical]
private static Stream ProcessHttpsFiles(Uri uri, Stream stream)
{
Stream bitmapStream = stream;
// This is the condition where the Bitmap has already been downloaded
// or the stream is not seekable
// using async dowload in that case simply return the original stream
// else you download the stream
if (bitmapStream == null || !bitmapStream.CanSeek)
{
WebRequest request = null;
// Block XDomain from apps deployed over HTTPS (For HTTP, LMZ and UNC apps, is ok to access images through HTTPS)
SecurityHelper.BlockCrossDomainForHttpsApps(uri);
// now, we can Assert permissions because we ensured that only apps deployed through non-HTTPS can access XDomain images
(new WebPermission(NetworkAccess.Connect, BindUriHelper.UriToString(uri))).Assert(); // BlessedAssert
try
{
request = WpfWebRequestHelper.CreateRequest(uri);
}
finally
{
WebPermission.RevertAssert();
}
bitmapStream = WpfWebRequestHelper.GetResponseStream(request);
}
return bitmapStream;
}
/// <SecurityNote>
/// Critical: This code elevates and extracts a bitmap stream
/// </SecurityNote>
[SecurityCritical]
private static Stream ProcessHttpFiles(Uri uri, Stream stream)
{
WebRequest request = null;
Stream bitmapStream = stream;
SecurityHelper.BlockCrossDomainForHttpsApps(uri);
// Download only if this content is not already downloaded or stream is not seekable
if (bitmapStream == null || !bitmapStream.CanSeek)
{
// In this case we first check to see if the consumer has media permissions for
// safe media (Site of Origin + Cross domain), if it
// does we assert and run the code that requires the assert
bool fElevate = false;
if (SecurityHelper.CallerHasMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.SafeImage))
{
fElevate = true;
}
if (fElevate)
{
(new WebPermission(NetworkAccess.Connect, BindUriHelper.UriToString(uri))).Assert(); // BlessedAssert
}
try
{
request = WpfWebRequestHelper.CreateRequest(uri);
}
finally
{
if (fElevate)
{
WebPermission.RevertAssert();
}
}
// Download only if this content is not already downloaded or stream is not seekable
bitmapStream = WpfWebRequestHelper.GetResponseStream(request);
}
return bitmapStream;
}
/// <SecurityNote>
/// Critical: This code elevates and extracts a bitmap stream
/// </SecurityNote>
[SecurityCritical]
private static Stream ProcessUncFiles(Uri uri)
{
Stream bitmapStream = null;
// perform checks for UNC content
SecurityHelper.EnforceUncContentAccessRules(uri);
// In this case we first check to see if the consumer has media permissions for
// safe media (Site of Origin + Cross domain), if it
// does then we assert else we run the code without the assert
bool fElevate = false;
if (SecurityHelper.CallerHasMediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.SafeImage))
{
fElevate = true;
}
if(fElevate)
{
// since the code above ensures that safe image permission is granted we
// can now do an assert to allow cross domain web request
(new FileIOPermission(FileIOPermissionAccess.Read, uri.LocalPath)).Assert(); // BlessedAssert
}
try
{
// FileStream does a demand for us, so no need to do a demand
bitmapStream = new System.IO.FileStream(uri.LocalPath, FileMode.Open, FileAccess.Read, FileShare.Read);
}
finally
{
if(fElevate)
{
FileIOPermission.RevertAssert();
}
}
return bitmapStream;
}
/// <SecurityNote>
/// Critical: This code is used to check and grant access to pixel data and metadata.
/// TreatAsSafe: This code does not elevate
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
void CheckIfSiteOfOrigin()
{
string uri = null;
if (CanConvertToString())
{
// This call returns the URI either as an absolute URI which the user
// passed in, in the first place or as the string "image"
// we only allow this code to succeed in the case of Uri and if it is site of
// origin or pack:. In all other conditions we fail
uri = ToString();
}
SecurityHelper.DemandMediaAccessPermission(uri);
}
/// Returns the decoder's CLSID
/// <SecurityNote>
/// Critical - access unmanaged code to retrieve CLSID.
/// </SecurityNote>
[SecurityCritical]
private static Guid GetCLSIDFromDecoder(SafeMILHandle decoderHandle, out string decoderMimeTypes)
{
Guid clsId;
// Get the decoder info
SafeMILHandle decoderInfo = new SafeMILHandle();
HRESULT.Check(UnsafeNativeMethods.WICBitmapDecoder.GetDecoderInfo(
decoderHandle,
out decoderInfo
));
// Get CLSID for the decoder
HRESULT.Check(UnsafeNativeMethods.WICBitmapCodecInfo.GetContainerFormat(decoderInfo, out clsId));
StringBuilder mimeTypes = null;
UInt32 length = 0;
// Find the length of the string needed
HRESULT.Check(UnsafeNativeMethods.WICBitmapCodecInfo.GetMimeTypes(
decoderInfo,
0,
mimeTypes,
out length
));
// get the string back
if (length > 0)
{
mimeTypes = new StringBuilder((int)length);
HRESULT.Check(UnsafeNativeMethods.WICBitmapCodecInfo.GetMimeTypes(
decoderInfo,
length,
mimeTypes,
out length
));
}
if (mimeTypes != null)
{
decoderMimeTypes = mimeTypes.ToString();
}
else
{
decoderMimeTypes = String.Empty;
}
return clsId;
}
/// Return a seekable stream if the current one is not seekable
private static System.IO.Stream GetSeekableStream(System.IO.Stream bitmapStream)
{
// MIL codecs require the source stream to be seekable. But if
// the source stream is an internet stream, it is not seekable.
// The data is probably not in the stream yet.
if (bitmapStream.CanSeek)
{
return bitmapStream;
}
// If the source is not seekable, we have to download the
// stream into a memory stream before we can decode it.
// ISSUE-2002/10/03--minliu: later on, if we can make MIL
// support progressive JPEG etc., we should take out the
// hack here and pass the network stream (CConectStream)
// directly to the unmanaged code
System.IO.MemoryStream memStream =
new System.IO.MemoryStream();
byte[] buffer = new byte[1024];
int read;
// Read all the bytes and write it to a memory stream
//
do
{
read = bitmapStream.Read(buffer, 0, 1024);
if (read <= 0)
{
break;
}
memStream.Write(buffer, 0, read);
} while (true);
// Reset the memory stream pointer back to the begining
memStream.Seek(0, System.IO.SeekOrigin.Begin);
// Use the new stream
return memStream;
}
/// Check the cache to see if decoder already exists
/// <SecurityNote>
/// Critical - Eventually calls code that calls unmanaged code.
/// TreatAsSafe - Only checks imaging cache to see object exists
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
private static BitmapDecoder CheckCache(
Uri uri,
out Guid clsId
)
{
clsId = Guid.Empty;
string mimeTypes;
if (uri != null)
{
WeakReference weakRef = ImagingCache.CheckDecoderCache(uri) as WeakReference;
if (weakRef != null)
{
BitmapDecoder bitmapDecoder = weakRef.Target as BitmapDecoder;
if ((bitmapDecoder != null) && bitmapDecoder.CheckAccess())
{
lock (bitmapDecoder.SyncObject)
{
clsId = GetCLSIDFromDecoder(bitmapDecoder.InternalDecoder, out mimeTypes);
return bitmapDecoder;
}
}
// Remove from the cache if bitmapDecoder is already been collected
if (bitmapDecoder == null)
{
ImagingCache.RemoveFromDecoderCache(uri);
}
}
}
return null;
}
/// <summary>
/// Initialize the codec.
/// </summary>
/// <SecurityNote>
/// Critical - Will eventually create a COM object, need to secure it
/// </SecurityNote>
[SecurityCritical]
private void Initialize(BitmapDecoder decoder)
{
_isBuiltInDecoder = true;
if (decoder != null)
{
SetupFrames(decoder, null);
//
// We need to keep the strong reference to the cached decoder for a few reasons:
//
// The application may release the original cached decoder and then keep a
// reference to this decoder only, in which case, the cache can be collected.
// This will cause a few undesirable results:
// 1. The application may choose to decode the same URI again in which case
// we will not retrieve it from the cache even though we have a copy already
// decoded.
// 2. The original cached decoder holds onto the file stream indirectly which if
// collected can cause bad behavior if the entire decoder is not loaded into
// memory.
//
_cachedDecoder = decoder;
}
else if ((_createOptions & BitmapCreateOptions.DelayCreation) == 0 && _cacheOption == BitmapCacheOption.OnLoad)
{
SetupFrames(null, null);
// Its ok to close the stream since the frames are not delay created and caching is immediate
CloseStream();
}
if ((_uri != null) && (decoder == null) && _shouldCacheDecoder)
{
// Add this decoder to the decoder cache
ImagingCache.AddToDecoderCache(
(_baseUri == null) ? _uri : new Uri(_baseUri, _uri),
new WeakReference(this)
);
}
}
/// <summary>
/// Closes the stream if its non-null
/// </summary>
/// <SecurityNote>
/// Critical - accesses critical resource _uriStream
/// TreatAsSafe - doesn't return the uriStream, just closes it which is safe
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
internal void CloseStream()
{
if (_uriStream != null)
{
_uriStream.Close();
_uriStream = null;
// The finalizer closes _uriStream, we already closed it so there's no need to run
// the finalizer anymore.
GC.SuppressFinalize(this);
}
}
/// <summary>
/// Sets up the frames collection.
/// Also, ensures that the frame collection for this decoder
/// will contain the same underlying frames as the collection
/// passed in. This is called by the LateBoundBitmapDecoder
/// </summary>
/// <SecurityNote>
/// Critical - access unmanaged code
/// TreatAsSafe - only access number of frames in the bitmap, a safe operation
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
internal void SetupFrames(BitmapDecoder decoder, ReadOnlyCollection<BitmapFrame> frames)
{
uint numFrames = 1;
HRESULT.Check(UnsafeNativeMethods.WICBitmapDecoder.GetFrameCount(_decoderHandle, out numFrames));
_frames = new List<BitmapFrame>((int)numFrames);
// initialize the list of frames to null.
// We'll fill it as it's used (pay for play).
for (int i = 0; i < (int)numFrames; i++)
{
if (i > 0 && _cacheOption != BitmapCacheOption.OnLoad)
{
_createOptions |= BitmapCreateOptions.DelayCreation;
}
BitmapFrameDecode bfd = null;
if ((frames != null) && (frames.Count == (i + 1)))
{
// If we already have a frames collection, get the BitmapFrame from it
bfd = frames[i] as BitmapFrameDecode;
bfd.UpdateDecoder(this);
}
else if (decoder == null)
{
// All frames should be frozen.
bfd = new BitmapFrameDecode(
i,
_createOptions,
_cacheOption,
this
);
bfd.Freeze();
}
else
{
// if we are creating from an existing cache, use the frames
// already stored in that cache
// All frames should be frozen.
bfd = new BitmapFrameDecode(
i,
_createOptions,
_cacheOption,
decoder.Frames[i] as BitmapFrameDecode
);
bfd.Freeze();
}
_frames.Add(bfd);
}
}
/// <summary>
/// Checks if the decoder is builtin. If not, throw exception
/// </summary>
private void EnsureBuiltInDecoder()
{
if (!_isBuiltInDecoder)
{
throw new NotImplementedException();
}
}
/// <summary>
/// Note, we must hold onto a reference to the managed stream
/// as long as we are using the unmanaged stream in the decoder.
/// This method may create a new managed stream.
///
[SecurityCritical]
private static IntPtr GetIStreamFromStream(ref System.IO.Stream bitmapStream)
{
IntPtr comStream = IntPtr.Zero;
// ensure the stream is seekable
bool seekable = bitmapStream.CanSeek;
if (bitmapStream is UnmanagedMemoryStream)
{
UnmanagedMemoryStream memoryStream = bitmapStream as UnmanagedMemoryStream;
IntPtr bufferPtr = IntPtr.Zero;
int length = 0;
unsafe
{
bufferPtr = (IntPtr) memoryStream.PositionPointer;
length = (int) memoryStream.Length;
}
if (bufferPtr != IntPtr.Zero)
{
comStream = StreamAsIStream.IStreamFrom(bufferPtr, length);
}
}
else
{
comStream = StreamAsIStream.IStreamFrom(bitmapStream);
if (comStream == IntPtr.Zero)
{
throw new System.InvalidOperationException(
SR.Get(SRID.Image_CantDealWithStream));
}
// If the stream is not seekable, we must create a
// seekable one for the decoder.
if (!seekable || ((!bitmapStream.CanWrite) && (bitmapStream.Length <= 1048576)))
{
IntPtr memoryStream = StreamAsIStream.IStreamMemoryFrom(comStream);
if (memoryStream != IntPtr.Zero)
{
// we don't need the original stream anymore
UnsafeNativeMethods.MILUnknown.ReleaseInterface(ref comStream);
bitmapStream = System.IO.Stream.Null;
return memoryStream;
}
else if (!seekable)
{
throw new System.InvalidOperationException(
SR.Get(SRID.Image_CantDealWithStream));
}
}
}
if (comStream == IntPtr.Zero)
{
throw new System.InvalidOperationException(
SR.Get(SRID.Image_CantDealWithStream));
}
return comStream;
}
/// Returns whether decoder can be converted to a string
internal bool CanConvertToString()
{
return (_uri != null);
}
#endregion
#region Internal Abstract
/// "Seals" the object
internal abstract void SealObject();
#endregion
#region Data Members
/// check to see if implementation is internal
private bool _isBuiltInDecoder;
/// Internal Decoder
private SafeMILHandle _decoderHandle;
/// flag to see if decoder should be inserted in the cache
private bool _shouldCacheDecoder = true;
/// flag to see if decoder should be inserted in the cache
private bool _isOriginalWritable = false;
/// If the palette is already cached
private bool _isPaletteCached;
/// Palette
private BitmapPalette _palette = null;
/// If the ColorContext is already cached
private bool _isColorContextCached = false;
/// ColorContexts collection
internal ReadOnlyCollection<ColorContext> _readOnlycolorContexts;
/// If the thumbnail is already cached
private bool _isThumbnailCached;
/// <summary>
/// Metadata
/// </summary>
/// <SecurityNote>
/// Critical - Access only granted if SiteOfOrigin demanded.
/// </SecurityNote>
[SecurityCritical]
private BitmapMetadata _metadata;
/// If the metadata is already cached
private bool _isMetadataCached;
/// Thumbnail
private BitmapSource _thumbnail = null;
/// CodecInfo
private BitmapCodecInfo _codecInfo;
/// If the preview is already cached
private bool _isPreviewCached;
/// Preview
private BitmapSource _preview = null;
/// Frames collection
internal List<BitmapFrame> _frames;
/// Frames collection
internal ReadOnlyCollection<BitmapFrame> _readOnlyFrames;
/// Stream
internal Stream _stream;
/// Uri
internal Uri _uri;
/// Base Uri, only stored internally. Not used for serialization
internal Uri _baseUri;
/// Uri Stream -- this is the stream that was created from the passed in Uri
/// <SecurityNote>
/// Critical: Obtained under elevation
/// </SecurityNote>
[SecurityCritical]
internal Stream _uriStream;
/// CreateOptions
internal BitmapCreateOptions _createOptions;
/// CacheOption
internal BitmapCacheOption _cacheOption;
/// Event helper for download completed event
internal UniqueEventHelper _downloadEvent = new UniqueEventHelper();
/// Event helper for download progress event
internal UniqueEventHelper<DownloadProgressEventArgs> _progressEvent = new UniqueEventHelper<DownloadProgressEventArgs>();
/// Event helper for download failed event
internal UniqueEventHelper<ExceptionEventArgs> _failedEvent = new UniqueEventHelper<ExceptionEventArgs>();
/// SyncObject
private object _syncObject = new Object();
// this is data that we cache as a performance optimization. It is ok to do so since we do not want to
// handle this key change in the lifetime of this app.
private static SecurityCriticalDataForSet<bool> isImageDisabled;
/// <SecurityNote>
/// Critical: This variable guards against reinitialization of the cached registry value
/// </SecurityNote>
[SecurityCritical]
private static bool isImageDisabledInitialized;
// For UnmanagedMemoryStream we want to make sure that buffer
// its pointing to is not getting release until decoder is alive
private UnmanagedMemoryStream _unmanagedMemoryStream;
/// <SecurityNote>
/// Critical: This variable guards against closing of the filehandle
/// which gets passed to unmanaged decoder.
/// </SecurityNote>
[SecurityCritical]
private SafeFileHandle _safeFilehandle;
private BitmapDecoder _cachedDecoder;
#endregion
}
#endregion // BitmapDecoder
}
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