Code:
/ DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Shared / MS / Internal / SecurityHelper.cs / 1 / SecurityHelper.cs
/****************************************************************************\
*
* File: SecurityHelper.cs
*
* Purpose: Helper functions that require elevation but are safe to use.
*
* Copyright (C) 2004 by Microsoft Corporation. All rights reserved.
*
\***************************************************************************/
// The SecurityHelper class differs between assemblies and could not actually be
// shared, so it is duplicated across namespaces to prevent name collision.
#if WINDOWS_BASE
namespace MS.Internal.WindowsBase
#elif PRESENTATION_CORE
namespace MS.Internal.PresentationCore
#elif PRESENTATIONFRAMEWORK
namespace MS.Internal.PresentationFramework
#elif PBTCOMPILER
namespace MS.Internal.PresentationBuildTasks
#elif REACHFRAMEWORK
namespace MS.Internal.ReachFramework
#elif DRT
namespace MS.Internal.Drt
#else
#error Class is being used from an unknown assembly.
#endif
{
using System;
using System.Globalization; // CultureInfo
using System.Security;
using System.Security.Permissions;
using System.Net; // WebPermission.
using System.ComponentModel;
using System.Security.Policy;
using System.Runtime.InteropServices;
using Microsoft.Win32;
#if !PBTCOMPILER
using MS.Win32;
using System.IO.Packaging;
#endif
#if WINDOWS_BASE || PRESENTATIONUI
using MS.Internal.Permissions;
#endif
#if PRESENTATION_CORE
using MS.Internal.AppModel;
#endif
#if PRESENTATIONFRAMEWORK_ONLY
using MS.Internal.Permissions ;
using System.Diagnostics;
using System.Windows;
using MS.Internal.Utility; // BindUriHelper
using System.Drawing.Printing; // PrintingPermission
using MS.Internal.AppModel;
#endif
#if REACHFRAMEWORK
using MS.Internal.Utility;
#endif
#if WINDOWS_BASE
[FriendAccessAllowed] // To allow FontCache service to see the WindowsBase variant of this class.
#endif
internal static class SecurityHelper
{
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK
///
/// Critical: This sets critical data
/// TreatAssafe: Setting it to null is ok
///
[SecurityCritical, SecurityTreatAsSafe]
static SecurityHelper()
{
_cachedPermissionSetAppDomain = null;
}
#endif
#if !PBTCOMPILER
internal static bool CheckUnmanagedCodePermission()
{
try
{
SecurityHelper.DemandUnmanagedCode();
}
catch(SecurityException )
{
return false ;
}
return true;
}
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandUnmanagedCode()
{
if(_unmanagedCodePermission == null)
{
_unmanagedCodePermission = new SecurityPermission(SecurityPermissionFlag.UnmanagedCode);
}
_unmanagedCodePermission.Demand();
}
static SecurityPermission _unmanagedCodePermission = null;
#endif // !PRESENTATION_CORE
#if PRESENTATIONFRAMEWORK
///
/// Critical: This code throws an exception if someone sets value to be true and we are in partial trust
/// TreatAsSafe: The only reason we mark this as critical is to track code
///
[SecurityCritical, SecurityTreatAsSafe]
internal static void ThrowExceptionIfSettingTrueInPartialTrust(ref bool value)
{
if (value == true && !SecurityHelper.CheckUnmanagedCodePermission())
{
value = false;
throw new SecurityException(SR.Get(SRID.SecurityExceptionForSettingSandboxExternalToTrue));
}
}
///
/// Check whether the call stack has the permissions needed for WebBrowser.
///
/// Right now we are just checking UIWindowPermission.
///
internal static bool CallerHasUnrestrictedWebBrowserPermission()
{
#if DEBUG
if (DebugAssumePartialTrust())
{
return false;
}
#endif
try
{
SecurityHelper.DemandWebBrowserPermission();
}
catch (SecurityException)
{
return false;
}
return true;
}
///
/// Check to see if we have User initiated navigation permission.
///
/// true if call stack has UserInitiatedNavigation permission
internal static bool CallerHasUserInitiatedNavigationPermission()
{
try
{
CreateUserInitiatedNavigationPermission();
_userInitiatedNavigationPermission.Demand();
}
catch (SecurityException)
{
return false;
}
return true;
}
///
/// Create a UserInitiatedNavigation permission.
/// Separate helper exists to make it easy to change what the permission is.
///
internal static CodeAccessPermission CreateUserInitiatedNavigationPermission()
{
if(_userInitiatedNavigationPermission == null)
{
_userInitiatedNavigationPermission = new UserInitiatedNavigationPermission();
}
return _userInitiatedNavigationPermission;
}
static UserInitiatedNavigationPermission _userInitiatedNavigationPermission = null;
///
/// Demands for permissions needed to construct the PrintDialog in
/// full trust mode and/or access full trust properties from dialog.
///
internal static void DemandPrintDialogPermissions()
{
if(_defaultPrintingPermission == null)
{
_defaultPrintingPermission = new PrintingPermission(PrintingPermissionLevel.DefaultPrinting);
}
_defaultPrintingPermission.Demand();
}
static PrintingPermission _defaultPrintingPermission = null;
///
/// Check to see if we have Reflection permission to create types and access members.
///
/// true if call stack has Reflection permission
internal static bool CallerHasMemberAccessReflectionPermission()
{
try
{
if (_reflectionPermission == null)
{
_reflectionPermission = new ReflectionPermission(ReflectionPermissionFlag.MemberAccess);
}
_reflectionPermission.Demand();
}
catch (SecurityException)
{
return false;
}
return true;
}
static ReflectionPermission _reflectionPermission = null;
///
/// Check to see if the caller is fully trusted.
///
/// true if call stack has unrestricted permission
internal static bool IsFullTrustCaller()
{
try
{
if (_fullTrustPermissionSet == null)
{
_fullTrustPermissionSet = new PermissionSet(PermissionState.Unrestricted);
}
_fullTrustPermissionSet.Demand();
}
catch (SecurityException)
{
return false;
}
return true;
}
static PermissionSet _fullTrustPermissionSet = null;
#endif
#if DEBUG && PRESENTATIONFRAMEWORK
///
/// Debug only code to eliminate first-chance exceptions when debugging.
/// If hosted in browser and a debugger is attached. Assume PT.
///
internal static bool DebugAssumePartialTrust()
{
if ( Debugger.IsAttached &&
Application.Current != null &&
Application.InBrowserHostedApp() == true )
{
return true ;
}
else
return false;
}
#endif
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK
///
/// Return true if the caller has the correct permission set to get a folder
/// path.
///
///
/// This function exists solely as a an optimazation for the debugger scenario
///
///
/// Critical: This code extracts the permission set associated with an appdomain by elevating
/// TreatAsSafe: The information is not exposed
///
[SecurityCritical,SecurityTreatAsSafe]
internal static bool CallerHasPermissionWithAppDomainOptimization(params IPermission[] permissionsToCheck)
{
// in case of passing null return true
if (permissionsToCheck == null)
return true;
PermissionSet psToCheck = new PermissionSet(PermissionState.None);
for ( int i = 0 ; i < permissionsToCheck.Length ; i++ )
{
psToCheck.AddPermission(permissionsToCheck[i]);
}
PermissionSet permissionSetAppDomain = ExtractAppDomainPermissionSet();
if (psToCheck.IsSubsetOf(permissionSetAppDomain))
{
return true;
}
return false;
}
#endif // PRESENTATIONFRAMEWORK
#if PRESENTATION_CORE
///
/// Critical: Elevates to extract the AppDomain BaseDirectory and returns it, which is sensitive information.
///
[SecurityCritical]
internal static Uri GetBaseDirectory(AppDomain domain)
{
Uri appBase = null;
new FileIOPermission(PermissionState.Unrestricted).Assert();// BlessedAssert
try
{
appBase = new Uri(domain.BaseDirectory);
}
finally
{
FileIOPermission.RevertAssert();
}
return( appBase );
}
//This code path is only executed if we are trying to get to http content from https
internal static Uri ExtractUriForClickOnceDeployedApp()
{
// This api returns the location from where an app was deployed. In case of browser hosted apps
// there are no elevations and this information is safe to return.
// In case of non browserhosted scenarios this will trigger a demand since we do not assert to get
// this information in the code below
return SiteOfOriginContainer.SiteOfOriginForBrowserApplications;
}
//This code path is only executed if we are trying to get to http content from https
///
/// Critical: Elevates to call code that extracts
/// the deployment code base and is used to make trust decisions
/// Assuming we are accessing http content from an https site it will
/// throw a demand
///
[SecurityCritical]
internal static void BlockCrossDomainForHttpsApps(Uri uri)
{
// if app is HTTPS, no cross domain allowed
Uri appDeploymentUri = ExtractUriForClickOnceDeployedApp();
if (appDeploymentUri != null && appDeploymentUri.Scheme == Uri.UriSchemeHttps)
{
// demand
if (uri.IsUnc || uri.IsFile)
{
(new FileIOPermission(FileIOPermissionAccess.Read, uri.LocalPath)).Demand();
}
else
{
(new WebPermission(NetworkAccess.Connect, BindUriHelper.UriToString(uri))).Demand();
}
}
}
// EnforceUncContentAccessRules implements UNC media & imaging access rules
///
/// Critical - calls MapUrlToZoneWrapper.
/// This is safe to be called by untrusted parties; all it does is demand permissions
/// if a condition for accessing Unc content is not satisfied, but since we want to track
/// its callers, we are not marking this as SecurityTreatAsSafe.
///
[SecurityCritical]
internal static void EnforceUncContentAccessRules(Uri contentUri)
{
// this should be called only for UNC content
Invariant.Assert(contentUri.IsUnc);
// get app zone and scheme
Uri appUri = SecurityHelper.ExtractUriForClickOnceDeployedApp();
if( appUri == null )
{
// we are not in a browser hosted app; we are not in partial trust, so don't block
return;
}
// get app's zone
int appZone = SecurityHelper.MapUrlToZoneWrapper(appUri);
// demand if
// 1) app comes from Internet or a more untrusted zone, or
// 2) app comes from Intranet and scheme is HTTPS
bool isInternetOrLessTrustedApp = (appZone >= MS.Win32.NativeMethods.URLZONE_INTERNET);
bool isIntranetHttpsApp = (appZone == MS.Win32.NativeMethods.URLZONE_INTRANET && appUri.Scheme == Uri.UriSchemeHttps);
if (isInternetOrLessTrustedApp || isIntranetHttpsApp)
{
// demand appropriate permission - we already know that contentUri is Unc
(new FileIOPermission(FileIOPermissionAccess.Read, contentUri.LocalPath)).Demand();
}
}
///
/// Critical: This code elevates to call MapUrlToZone in the form of a SUC
///
[SecurityCritical]
internal static int MapUrlToZoneWrapper(Uri uri)
{
int targetZone = NativeMethods.URLZONE_LOCAL_MACHINE ; // fail securely this is the most priveleged zone
int hr = NativeMethods.S_OK ;
object curSecMgr = null;
hr = UnsafeNativeMethods.CoInternetCreateSecurityManager(
null,
out curSecMgr ,
0 );
if ( NativeMethods.Failed( hr ))
throw new Win32Exception( hr ) ;
UnsafeNativeMethods.IInternetSecurityManager pSec = (UnsafeNativeMethods.IInternetSecurityManager) curSecMgr;
string uriString = BindUriHelper.UriToString( uri ) ;
//
// special case the condition if file is on local machine or UNC to ensure that content with mark of the web
// does not yield with an internet zone result
//
if (uri.IsFile)
{
pSec.MapUrlToZone( uriString, out targetZone, MS.Win32.NativeMethods.MUTZ_NOSAVEDFILECHECK );
}
else
{
pSec.MapUrlToZone( uriString, out targetZone, 0 );
}
//
// This is the condition for Invalid zone
//
if (targetZone < 0)
{
throw new SecurityException( SR.Get(SRID.Invalid_URI) );
}
pSec = null;
curSecMgr = null;
return targetZone;
}
///
/// determines if the current call stack has the serialization formatter
/// permission. This is one of the few CLR checks that doesn't have a
/// bool version - you have to let the check fail and catch the exception.
///
/// Because this is a check *at that point*, you may not cache this value.
///
/// true if call stack has the serialization permission
internal static bool CallerHasSerializationPermission()
{
try
{
if(_serializationSecurityPermission == null)
{
_serializationSecurityPermission = new SecurityPermission(SecurityPermissionFlag.SerializationFormatter);
}
_serializationSecurityPermission.Demand();
}
catch (SecurityException)
{
return false;
}
return true;
}
static SecurityPermission _serializationSecurityPermission = null;
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandFilePathDiscoveryWriteRead()
{
FileIOPermission permobj = new FileIOPermission(PermissionState.None);
permobj.AllFiles = FileIOPermissionAccess.Write|FileIOPermissionAccess.Read |FileIOPermissionAccess.PathDiscovery;
permobj.Demand();
}
#endif
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK
///
/// Critical: This extracts permission set for app domain
///
[SecurityCritical]
internal static PermissionSet ExtractAppDomainPermissionSetMinusSiteOfOrigin()
{
// there is an invariant assert for null check in the code code that extracts the app domain
PermissionSet permissionSetAppDomain = ExtractAppDomainPermissionSet();
// Ensure we remove the FileIO read permission to site of origin
// we choose to use unrestricted here because it does not matter
// matter which specific variant of Fileio/Web permission we use
// since we are using an overload to check and remove permission
// that works on type. There is not a way to remove some part
// part of a permission, although we could remove this and add
// add back the delta if the existing permission set had more than the ones
// we care about but it is really the path we are targetting here since
// that is what causes the delta and hence we are removing it all together.
Uri siteOfOrigin = SiteOfOriginContainer.SiteOfOrigin;
CodeAccessPermission siteOfOriginReadPermission = null;
if (siteOfOrigin.Scheme == Uri.UriSchemeFile)
{
siteOfOriginReadPermission = new FileIOPermission(PermissionState.Unrestricted);
}
else if (siteOfOrigin.Scheme == Uri.UriSchemeHttp)
{
siteOfOriginReadPermission = new WebPermission(PermissionState.Unrestricted);
}
if (siteOfOriginReadPermission != null)
{
if (permissionSetAppDomain.GetPermission(siteOfOriginReadPermission.GetType()) != null)
{
permissionSetAppDomain.RemovePermission(siteOfOriginReadPermission.GetType());
}
}
return permissionSetAppDomain;
}
///
/// Critical: This extracts permission set for app domain
///
[SecurityCritical]
internal static PermissionSet ExtractAppDomainPermissionSet()
{
PermissionSet permissionSetAppDomain = null;
//
// Performance optimization to avoid calling Resolve Policy over and over since it is expensive
//
if (_cachedPermissionSetAppDomain != null)
{
return _cachedPermissionSetAppDomain;
}
// There is no deterministic way to get this for all concievble scenarios so what we use
// is a heuristic that first does the most common place scenario which is to look in app trust
// If that fails we go into IsDefaultAppDomain
// If that fails then we go into the condition to check if it we can use evidence
if (AppDomain.CurrentDomain.ApplicationTrust != null) // This could be null in full trust
{
permissionSetAppDomain = AppDomain.CurrentDomain.ApplicationTrust.DefaultGrantSet.PermissionSet;
}
else if (AppDomain.CurrentDomain.IsDefaultAppDomain()) // this is the condition where we use the defualt app domain
{
/*
THIS IS TRUE IN WHIDBEY BUT MIGHT NOT HOLD TRUE GOING FORWARD PLEASE
ENSURE ANY CODE CHANGES HERE ARE REVIEWED BY [....] AND [....] !!!!
ALSO ENSURE THAT WE VALIDATE THIS OVER TIME
*/
permissionSetAppDomain = new PermissionSet(PermissionState.Unrestricted);
}
else
{
Evidence evidence;
(new SecurityPermission(SecurityPermissionFlag.ControlEvidence)).Assert();//BlessedAssert
try
{
evidence = AppDomain.CurrentDomain.Evidence;
}
finally
{
SecurityPermission.RevertAssert();
}
permissionSetAppDomain = SecurityManager.ResolveSystemPolicy(evidence);
}
Invariant.Assert(permissionSetAppDomain != null);
//
// cache this for performance optimization
//
_cachedPermissionSetAppDomain = permissionSetAppDomain;
return permissionSetAppDomain;
}
///
/// Critical: This holds permissionset for appdomain obtained because of an elevation
///
[SecurityCritical]
private static PermissionSet _cachedPermissionSetAppDomain;
///
/// determines if the current call stack has the all clipboard
/// permission. This is one of the few CLR checks that doesn't have a
/// bool version - you have to let the check fail and catch the exception.
///
/// Because this is a check *at that point*, you may not cache this value.
///
/// true if call stack has the all clipboard
internal static bool CallerHasAllClipboardPermission()
{
try
{
SecurityHelper.DemandAllClipboardPermission();
}
catch (SecurityException)
{
return false;
}
return true;
}
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandAllClipboardPermission()
{
if(_uiPermissionAllClipboard == null)
{
_uiPermissionAllClipboard = new UIPermission(UIPermissionClipboard.AllClipboard);
}
_uiPermissionAllClipboard.Demand();
}
static UIPermission _uiPermissionAllClipboard = null;
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandPathDiscovery(string path)
{
new FileIOPermission(FileIOPermissionAccess.PathDiscovery, path).Demand();
}
internal static bool CheckEnvironmentPermission()
{
try
{
SecurityHelper.DemandEnvironmentPermission();
}
catch (SecurityException)
{
return false ;
}
return true;
}
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandEnvironmentPermission()
{
if(_unrestrictedEnvironmentPermission == null)
{
_unrestrictedEnvironmentPermission = new EnvironmentPermission(PermissionState.Unrestricted);
}
_unrestrictedEnvironmentPermission.Demand();
}
static EnvironmentPermission _unrestrictedEnvironmentPermission = null;
#endif // PRESENTATION_CORE || PRESENTATIONFRAMEWORK
#if PRESENTATION_CORE
///
/// Critical: Calls a critical method that returns a permission object.
/// Safe: Demands are safe.
///
[SecurityCritical, SecurityTreatAsSafe]
internal static void DemandUriDiscoveryPermission(Uri uri)
{
CodeAccessPermission permission = CreateUriDiscoveryPermission(uri);
if (permission != null)
permission.Demand();
}
///
/// Critical: Returns a permission object, which can be misused.
///
[SecurityCritical]
internal static CodeAccessPermission CreateUriDiscoveryPermission(Uri uri)
{
// explicitly disallow sub-classed Uris to guard against
// exploits where we "lie" about some of the properties on the Uri.
// and then later change the value returned
// ( e.g. supply a different uri from what checked here)
if (uri.GetType().IsSubclassOf(typeof(Uri)))
{
DemandInfrastructurePermission();
}
if (uri.IsFile)
return new FileIOPermission(FileIOPermissionAccess.PathDiscovery, uri.LocalPath);
// Add appropriate demands for other Uri types here.
return null;
}
///
/// Critical: Returns a permission object, which can be misused.
///
[SecurityCritical]
internal static CodeAccessPermission CreateUriReadPermission(Uri uri)
{
// explicitly disallow sub-classed Uris to guard against
// exploits where we "lie" about some of the properties on the Uri.
// and then later change the value returned
// ( e.g. supply a different uri from what checked here)
if (uri.GetType().IsSubclassOf(typeof(Uri)))
{
DemandInfrastructurePermission();
}
if (uri.IsFile)
return new FileIOPermission(FileIOPermissionAccess.Read, uri.LocalPath);
// Add appropriate demands for other Uri types here.
return null;
}
///
/// Critical: Calls a critical method that returns a permission object.
/// Safe: Demands are safe.
///
[SecurityCritical, SecurityTreatAsSafe]
internal static void DemandUriReadPermission(Uri uri)
{
CodeAccessPermission permission = CreateUriReadPermission(uri);
if (permission != null)
permission.Demand();
}
///
/// Checks whether the caller has path discovery permission for the input path.
///
/// Full path to a file or a directory.
/// true if the caller has the discovery permission, false otherwise.
internal static bool CallerHasPathDiscoveryPermission(string path)
{
try
{
DemandPathDiscovery(path);
return true;
}
catch (SecurityException)
{
return false;
}
}
#endif
#if WINDOWS_BASE
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandRightsManagementPermission()
{
if(_rightsManagementPermission == null)
{
_rightsManagementPermission = new RightsManagementPermission();
}
_rightsManagementPermission.Demand();
}
static RightsManagementPermission _rightsManagementPermission = null;
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandCompoundFileIOPermission()
{
if(_compoundFileIOPermission == null)
{
_compoundFileIOPermission = new CompoundFileIOPermission();
}
_compoundFileIOPermission.Demand();
}
static CompoundFileIOPermission _compoundFileIOPermission = null;
///
/// The permission set required to use encrypted package envelopes
///
internal static PermissionSet EnvelopePermissionSet
{
get
{
if (_envelopePermissionSet == null)
{
_envelopePermissionSet = CreateEnvelopePermissionSet();
}
return _envelopePermissionSet;
}
}
private static PermissionSet _envelopePermissionSet = null;
///
/// Creates a permission set that includes all permissions necessary to
/// use EncryptedPackageEnvelope.
///
/// The appropriate permission set
private static PermissionSet CreateEnvelopePermissionSet()
{
PermissionSet permissionSet = new PermissionSet(PermissionState.None);
permissionSet.AddPermission(new RightsManagementPermission());
permissionSet.AddPermission(new CompoundFileIOPermission());
return permissionSet;
}
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandPathDiscovery(string path)
{
FileIOPermission permobj = new FileIOPermission(PermissionState.None);
permobj.AddPathList(FileIOPermissionAccess.PathDiscovery, path);
permobj.Demand();
}
#endif // WINDOWS_BASE
#if WINDOWS_BASE || DRT || PBTCOMPILER || PRESENTATIONFRAMEWORK
///
/// Critical: This calls into Marshal.SizeOf which has a link demand
/// TreatAsSafe: Determining size is deemed as a safe operation
///
[SecurityCritical,SecurityTreatAsSafe]
internal static int SizeOf(Type t)
{
return Marshal.SizeOf(t);
}
#endif
#if WINDOWS_BASE || DRT
///
/// Critical: This calls into Marshal.SizeOf which has a link demand
/// TreatAsSafe: Determining size is deemed as a safe operation
///
[SecurityCritical,SecurityTreatAsSafe]
internal static int SizeOf(Object o)
{
return Marshal.SizeOf(o);
}
#endif
#if PRESENTATION_CORE
///
/// Critical: This calls into Marshal.GetHRForException which has a link demand
/// TreatAsSafe: Getting an HRESULT is deemed as a safe operation
///
[SecurityCritical,SecurityTreatAsSafe]
internal static int GetHRForException(Exception e)
{
return Marshal.GetHRForException(e);
}
///
/// Critical: This calls into SafeHandle.get_IsInvalid which has a link demand
/// TreatAsSafe: Finding out if a handle is valid is deemed as a safe operation
///
[SecurityCritical,SecurityTreatAsSafe]
internal static bool SafeHandleIsInvalid(SafeHandle sh)
{
return sh.IsInvalid;
}
#endif
#if PRESENTATIONFRAMEWORK || WINDOWS_BASE
///
/// Critical: This calls into Marshal.ThrowExceptionForHR which has a link demand
/// TreatAsSafe: Throwing an exception is deemed as a safe operation (throwing exceptions is allowed in Partial Trust)
///
[SecurityCritical,SecurityTreatAsSafe]
internal static void ThrowExceptionForHR(int hr)
{
Marshal.ThrowExceptionForHR(hr);
}
#endif
#if PRESENTATION_CORE
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandRegistryPermission()
{
if(_unrestrictedRegistryPermission == null)
{
_unrestrictedRegistryPermission = new RegistryPermission(PermissionState.Unrestricted);
}
_unrestrictedRegistryPermission.Demand();
}
static RegistryPermission _unrestrictedRegistryPermission = null;
#endif // PRESENTATION_CORE
#if !PBTCOMPILER
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandUIWindowPermission()
{
if(_allWindowsUIPermission == null)
{
_allWindowsUIPermission = new UIPermission(UIPermissionWindow.AllWindows);
}
_allWindowsUIPermission.Demand();
}
static UIPermission _allWindowsUIPermission = null;
#endif
#if PRESENTATIONFRAMEWORK || PRESENTATION_CORE
///
/// Demand infrastructure permission.
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandInfrastructurePermission()
{
if(_infrastructurePermission == null)
{
_infrastructurePermission = new SecurityPermission( SecurityPermissionFlag.Infrastructure );
}
_infrastructurePermission.Demand();
}
static SecurityPermission _infrastructurePermission = null;
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandWebBrowserPermission()
{
if(_webBrowserPermission == null)
{
_webBrowserPermission = new WebBrowserPermission(PermissionState.Unrestricted);
}
_webBrowserPermission.Demand();
}
static WebBrowserPermission _webBrowserPermission = null;
#endif
#if PRESENTATION_CORE || REACHFRAMEWORK
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandMediaPermission(MediaPermissionAudio audioPermissionToDemand,
MediaPermissionVideo videoPermissionToDemand,
MediaPermissionImage imagePermissionToDemand)
{
// Demand the appropriate permission
(new MediaPermission(audioPermissionToDemand,
videoPermissionToDemand,
imagePermissionToDemand )).Demand();
}
///
/// Check whether the call stack has the permissions needed for safe media.
///
///
internal static bool CallerHasMediaPermission(MediaPermissionAudio audioPermissionToDemand,
MediaPermissionVideo videoPermissionToDemand,
MediaPermissionImage imagePermissionToDemand)
{
try
{
(new MediaPermission(audioPermissionToDemand,videoPermissionToDemand,imagePermissionToDemand)).Demand();
return true;
}
catch(SecurityException)
{
return false;
}
}
#endif
// don't include this in the compiler - avoid compiler changes when we can.
#if !PBTCOMPILER
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandUnrestrictedUIPermission()
{
if(_unrestrictedUIPermission == null)
{
_unrestrictedUIPermission = new UIPermission(PermissionState.Unrestricted);
}
_unrestrictedUIPermission.Demand();
}
static UIPermission _unrestrictedUIPermission = null;
#endif
#if PRESENTATION_CORE
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandFileIOReadPermission(string fileName)
{
new FileIOPermission(FileIOPermissionAccess.Read, fileName).Demand();
}
#endif
#if NEVER
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandFileDialogSavePermission()
{
if(_fileDialogSavePermission == null)
{
_fileDialogSavePermission = new FileDialogPermission(FileDialogPermissionAccess.Save);
}
_fileDialogSavePermission.Demand();
}
static FileDialogPermission _fileDialogSavePermission = null;
#endif
#if PRESENTATIONFRAMEWORK
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandUnrestrictedFileIOPermission()
{
if(_unrestrictedFileIOPermission == null)
{
_unrestrictedFileIOPermission = new FileIOPermission(PermissionState.Unrestricted);
}
_unrestrictedFileIOPermission.Demand();
}
static FileIOPermission _unrestrictedFileIOPermission = null;
///
/// Not marked Critical: demands do not constitute security critical code
///
internal static void DemandFileDialogOpenPermission()
{
if(_fileDialogOpenPermission == null)
{
_fileDialogOpenPermission = new FileDialogPermission(FileDialogPermissionAccess.Open);
}
_fileDialogOpenPermission.Demand();
}
static FileDialogPermission _fileDialogOpenPermission = null;
///
/// A helper method to do the necessary work to display a standard MessageBox. This method performs
/// and necessary elevations to make the dialog work as well.
///
///
/// Critical - Elevates for unmanaged code permissions to display a messagebox (internally, it calls
/// MessageBox WIN32 API).
/// TreatAsSafe - The MessageBox API takes a static strings and known enums as input. There is nothing
/// unsafe with the dialog and it is not spoofable from Avalon as it is a Win32 window.
///
[SecurityCritical, SecurityTreatAsSafe]
internal
static
void
ShowMessageBoxHelper(
System.Windows.Window parent,
string text,
string title,
System.Windows.MessageBoxButton buttons,
System.Windows.MessageBoxImage image
)
{
(new SecurityPermission(SecurityPermissionFlag.UnmanagedCode)).Assert();
try
{
// if we have a known parent window set, let's use it when alerting the user.
if (parent != null)
{
System.Windows.MessageBox.Show(parent, text, title, buttons, image);
}
else
{
System.Windows.MessageBox.Show(text, title, buttons, image);
}
}
finally
{
SecurityPermission.RevertAssert();
}
}
#endif
#if PRESENTATION_CORE || REACHFRAMEWORK
///
/// Demands do not constitute criticality
///
internal static void DemandMediaAccessPermission(String uri)
{
CodeAccessPermission casPermission= SecurityHelper.CreateMediaAccessPermission(uri);
if(casPermission != null)
{
casPermission.Demand();
}
}
#endif
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK || REACHFRAMEWORK
///
/// Creating a permission set is a safe operation
///
internal
static
CodeAccessPermission
CreateMediaAccessPermission(String uri)
{
CodeAccessPermission codeAccessPermission = null;
if (uri != null)
{
// do a Case invariant dotnet culture specific string compare
if (String.Compare(SafeSecurityHelper.IMAGE, uri, true/*Ignore case*/, CultureInfo.GetCultureInfo(SafeSecurityHelper.DOTNETCULTURE)) == 0)
{
codeAccessPermission = new MediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.AllImage);
}
else
{
// we allow access to pack: bits so assuming scheme is not pack: we demand
if (String.Compare((System.Windows.Navigation.BaseUriHelper.GetResolvedUri(System.Windows.Navigation.BaseUriHelper.BaseUri, new Uri(uri, UriKind.RelativeOrAbsolute))).Scheme,
PackUriHelper.UriSchemePack, true /* ignore case */,
CultureInfo.GetCultureInfo(SafeSecurityHelper.DOTNETCULTURE)) != 0)
{
// Creating a URI is fine it is going the other way that is risky
if(!SecurityHelper.CallerHasWebPermission(new Uri(uri,UriKind.RelativeOrAbsolute)))
{
codeAccessPermission = new MediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.AllImage);
}
}
}
}
else
{
codeAccessPermission = new MediaPermission(MediaPermissionAudio.NoAudio,
MediaPermissionVideo.NoVideo,
MediaPermissionImage.AllImage);
}
return codeAccessPermission;
}
///
/// Check caller has web-permission. for a given Uri.
///
internal static bool CallerHasWebPermission( Uri uri )
{
try
{
SecurityHelper.DemandWebPermission(uri);
return true;
}
catch ( SecurityException )
{
return false ;
}
}
internal static void DemandWebPermission( Uri uri )
{
// We do this first as a security measure since the call below
// checks for derivatives. Please note we need to extract the
// string to call into WebPermission anyways, the only thing that
// doing this early gains us is a defense in depth measure. The call
// is required nevertheless.
string finalUri = BindUriHelper.UriToString( uri );
if (uri.IsFile)
{
// If the scheme is file: demand file io
string toOpen = uri.LocalPath;
(new FileIOPermission(FileIOPermissionAccess.Read, toOpen)).Demand();
}
else
{
// else demand web permissions
new WebPermission(NetworkAccess.Connect, finalUri).Demand();
}
}
#endif //PRESENTATIONCORE||PRESENTATIONFRAMEWORK||REACHFRAMEWORK
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK || REACHFRAMEWORK
///
/// Demands do not constitute criticality
///
///
/// By default none of the plug-in serializer code must succeed for partially trusted callers
///
internal static void DemandPlugInSerializerPermissions()
{
if(_plugInSerializerPermissions == null)
{
_plugInSerializerPermissions = new PermissionSet(PermissionState.Unrestricted);
}
_plugInSerializerPermissions.Demand();
}
static PermissionSet _plugInSerializerPermissions = null;
#endif //PRESENTATIONFRAMEWORK
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK || WINDOWS_BASE
///
/// This method has security implications: Mime\ContentTypes\Uri schemes types are served in a case-insensitive fashion; they MUST be compared that way
///
internal static bool AreStringTypesEqual(string m1, string m2)
{
return (String.Compare(m1, m2, StringComparison.OrdinalIgnoreCase) == 0);
}
#endif //PRESENTATION_CORE || PRESENTATIONFRAMEWORK || WINDOWS_BASE
#if WINDOWS_BASE
///
/// Read and return a registry value.
///
/// Critical - Asserts registry permission on the caller-provided key.
///
///
[SecurityCritical]
static internal object ReadRegistryValue( RegistryKey baseRegistryKey, string keyName, string valueName )
{
object value = null;
new RegistryPermission(RegistryPermissionAccess.Read, baseRegistryKey.Name + @"\" + keyName).Assert();
try
{
RegistryKey key = baseRegistryKey.OpenSubKey(keyName);
if (key != null)
{
using( key )
{
value = key.GetValue(valueName);
}
}
}
finally
{
RegistryPermission.RevertAssert();
}
return value;
}
#endif // WINDOWS_BASE
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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- Matrix3DValueSerializer.cs
- TypeConverters.cs
- DataControlFieldCell.cs
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- ImageConverter.cs
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- mediaeventshelper.cs
- DiagnosticTrace.cs
- WaitHandleCannotBeOpenedException.cs
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- QuerySettings.cs
- TextTreeObjectNode.cs
- EntityObject.cs
- TextSpan.cs
- ZipIOCentralDirectoryBlock.cs
- ParserExtension.cs
- RequestQueue.cs
- StatusBarPanelClickEvent.cs
- TreeSet.cs
- DispatcherHookEventArgs.cs
- WaitForChangedResult.cs
- ScaleTransform.cs
- RequestCachePolicy.cs
- RectAnimationUsingKeyFrames.cs
- validationstate.cs
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