Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Shared / MS / Internal / SecurityHelper.cs / 1407647 / 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.
// [[....], June'09] This duplication seems hardly necessary now. We should continue
// trying to reduce it by pushing things from Framework to Core (whenever it makes sense).
#if WINDOWS_BASE
namespace MS.Internal.WindowsBase
#elif PRESENTATION_CORE
using MS.Internal.PresentationCore;
namespace MS.Internal // Promote the one from PresentationCore as the default to use.
#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;
using System.Windows.Markup;
using System.Diagnostics.CodeAnalysis;
#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;
using MS.Internal.Permissions;
#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 !PBTCOMPILER
internal static bool CheckUnmanagedCodePermission()
{
try
{
SecurityHelper.DemandUnmanagedCode();
}
catch(SecurityException )
{
return false ;
}
return true;
}
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandUnmanagedCode()
{
if(_unmanagedCodePermission == null)
{
_unmanagedCodePermission = new SecurityPermission(SecurityPermissionFlag.UnmanagedCode);
}
_unmanagedCodePermission.Demand();
}
static SecurityPermission _unmanagedCodePermission = null;
#endif // !PBTCOMPILER
#if PRESENTATION_CORE
///
/// Create a UserInitiatedRoutedEvent permission.
/// Separate helper exists to make it easy to change what the permission is.
///
internal static CodeAccessPermission CreateUserInitiatedRoutedEventPermission()
{
if(_userInitiatedRoutedEventPermission == null)
{
_userInitiatedRoutedEventPermission = new UserInitiatedRoutedEventPermission();
}
return _userInitiatedRoutedEventPermission;
}
///
/// Check whether the call stack has the permissions needed for UserInitiated RoutedEvents.
///
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static bool CallerHasUserInitiatedRoutedEventPermission()
{
try
{
CreateUserInitiatedRoutedEventPermission().Demand();
}
catch (SecurityException)
{
return false;
}
return true;
}
static UserInitiatedRoutedEventPermission _userInitiatedRoutedEventPermission = 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));
}
}
internal static void DemandWebBrowserPermission()
{
CachedWebBrowserPermission.Demand();
}
internal static WebBrowserPermission CachedWebBrowserPermission
{
get
{
if (_webBrowserPermission == null)
{
_webBrowserPermission = new WebBrowserPermission(PermissionState.Unrestricted);
}
return _webBrowserPermission;
}
}
static WebBrowserPermission _webBrowserPermission;
///
/// Check whether the call stack has the permissions needed for WebBrowser.
/// Optimization: false is returned if the AppDomain's permission grant does not include the
/// WebBrowserPermission. This preliminary check will defeat an Assert on the callstack, but it
/// avoids the SecurityException in PT when the full WB permission is not granted.
///
internal static bool CallerAndAppDomainHaveUnrestrictedWebBrowserPermission()
{
if (!MS.Internal.SecurityHelper.AppDomainHasPermission(CachedWebBrowserPermission))
return false;
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;
#endif
#if PRESENTATION_CORE
///
/// Check to see if the caller is fully trusted.
///
/// true if call stack has unrestricted permission
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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;
///
/// 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 = AppDomain.CurrentDomain.PermissionSet;
if (psToCheck.IsSubsetOf(permissionSetAppDomain))
{
return true;
}
return false;
}
/// Enables an efficient check for a specific permisison in the AppDomain's permission grant
/// without having to catch a SecurityException in the case the permission is not granted.
///
///
/// Caveat: This is not a generally valid substitute for doing a full Demand. The main cases not
/// covered are:
/// 1) call from PT AppDomain into full-trust one;
/// 2) captured PT callstack (via ExecutionContext) from another thread or context. Our Dispatcher
/// does this.
///
/// Critical: Accesses the Critical AppDomain.PermissionSet, which might contain sensitive information
/// such as file paths.
/// Safe: PT code could get the information exposed by doing a Demand and catching a SecurityException.
///
[SecurityCritical,SecurityTreatAsSafe]
internal static bool AppDomainHasPermission(IPermission permissionToCheck)
{
Invariant.Assert(permissionToCheck != null);
PermissionSet psToCheck = new PermissionSet(PermissionState.None);
psToCheck.AddPermission(permissionToCheck);
return psToCheck.IsSubsetOf(AppDomain.CurrentDomain.PermissionSet);
}
///
/// 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.SiteOfOriginForClickOnceApp;
}
//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;
}
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandFilePathDiscoveryWriteRead()
{
FileIOPermission permobj = new FileIOPermission(PermissionState.None);
permobj.AllFiles = FileIOPermissionAccess.Write|FileIOPermissionAccess.Read |FileIOPermissionAccess.PathDiscovery;
permobj.Demand();
}
///
/// Critical: This extracts permission set for app domain
///
[SecurityCritical]
internal static PermissionSet ExtractAppDomainPermissionSetMinusSiteOfOrigin()
{
PermissionSet permissionSetAppDomain = AppDomain.CurrentDomain.PermissionSet;
// 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 of a permission, although we could remove this and 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 targeting 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());
// Failing on a ReadOnlyPermissionSet here? See Dev10.697110.
}
}
return permissionSetAppDomain;
}
#endif
#if PRESENTATION_CORE
///
/// 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
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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;
///
/// 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;
}
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandAllClipboardPermission()
{
if(_uiPermissionAllClipboard == null)
{
_uiPermissionAllClipboard = new UIPermission(UIPermissionClipboard.AllClipboard);
}
_uiPermissionAllClipboard.Demand();
}
static UIPermission _uiPermissionAllClipboard = null;
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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;
}
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandEnvironmentPermission()
{
if(_unrestrictedEnvironmentPermission == null)
{
_unrestrictedEnvironmentPermission = new EnvironmentPermission(PermissionState.Unrestricted);
}
_unrestrictedEnvironmentPermission.Demand();
}
static EnvironmentPermission _unrestrictedEnvironmentPermission = null;
///
/// 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;
}
}
///
/// 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;
}
#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;
///
/// 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();
}
///
/// SecurityCritical is needed due to Dev10 bug 534574. This is a TEMPORARY WORKAROUND for v4.
/// TAS: Callers are transparent, so we need this too to keep them working.
///
/// Note that the XAML reader relies on being able to call RunClassConstructor() on non-public types.
/// This is considered a security flaw, and a future version of the CLR will likely plug it.
///
[SecurityCritical, SecurityTreatAsSafe]
internal static void RunClassConstructor(Type t)
{
System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(t.TypeHandle);
}
#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
///
/// The LinkDemand on Marshal.SizeOf() was removed in v4.
[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 WINDOWS_BASE || PRESENTATION_CORE
///
/// 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
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandRegistryPermission()
{
if(_unrestrictedRegistryPermission == null)
{
_unrestrictedRegistryPermission = new RegistryPermission(PermissionState.Unrestricted);
}
_unrestrictedRegistryPermission.Demand();
}
static RegistryPermission _unrestrictedRegistryPermission = null;
#endif // PRESENTATION_CORE
#if !PBTCOMPILER
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandUIWindowPermission()
{
if(_allWindowsUIPermission == null)
{
_allWindowsUIPermission = new UIPermission(UIPermissionWindow.AllWindows);
}
_allWindowsUIPermission.Demand();
}
static UIPermission _allWindowsUIPermission = null;
#endif
#if PRESENTATION_CORE
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandInfrastructurePermission()
{
if(_infrastructurePermission == null)
{
_infrastructurePermission = new SecurityPermission( SecurityPermissionFlag.Infrastructure );
}
_infrastructurePermission.Demand();
}
static SecurityPermission _infrastructurePermission = null;
#endif
#if PRESENTATION_CORE || REACHFRAMEWORK
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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.
///
///
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandUnrestrictedUIPermission()
{
if(_unrestrictedUIPermission == null)
{
_unrestrictedUIPermission = new UIPermission(PermissionState.Unrestricted);
}
_unrestrictedUIPermission.Demand();
}
static UIPermission _unrestrictedUIPermission = null;
#endif
#if PRESENTATION_CORE
internal static bool AppDomainGrantedUnrestrictedUIPermission
{
[SecurityCritical]
get
{
if(!_appDomainGrantedUnrestrictedUIPermission.HasValue)
{
_appDomainGrantedUnrestrictedUIPermission = AppDomainHasPermission(new UIPermission(PermissionState.Unrestricted));
}
return _appDomainGrantedUnrestrictedUIPermission.Value;
}
}
[SecurityCritical]
private static bool? _appDomainGrantedUnrestrictedUIPermission;
#endif
#if PRESENTATION_CORE
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandFileIOReadPermission(string fileName)
{
new FileIOPermission(FileIOPermissionAccess.Read, fileName).Demand();
}
#endif
#if NEVER
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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();
}
}
///
/// 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(
IntPtr parentHwnd,
string text,
string title,
System.Windows.MessageBoxButton buttons,
System.Windows.MessageBoxImage image
)
{
(new SecurityPermission(SecurityPermissionFlag.UnmanagedCode)).Assert();
try
{
// NOTE: the last param must always be MessageBoxOptions.None for this to be considered TreatAsSafe
System.Windows.MessageBox.ShowCore(parentHwnd, text, title, buttons, image, MessageBoxResult.None, MessageBoxOptions.None);
}
finally
{
SecurityPermission.RevertAssert();
}
}
#endif
#if PRESENTATION_CORE || REACHFRAMEWORK
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
internal static void DemandMediaAccessPermission(String uri)
{
CodeAccessPermission casPermission= SecurityHelper.CreateMediaAccessPermission(uri);
if(casPermission != null)
{
casPermission.Demand();
}
}
#endif
#if PRESENTATION_CORE || 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*/, TypeConverterHelper.InvariantEnglishUS ) == 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 */,
TypeConverterHelper.InvariantEnglishUS) != 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 ;
}
}
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
[SecuritySafeCritical]
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||REACHFRAMEWORK
#if PRESENTATION_CORE || PRESENTATIONFRAMEWORK || REACHFRAMEWORK
///
/// Critical - Performs a demand. Transparent methods should not be responsible
/// for verifying the security of an operation, and therefore should not demand permissions.
/// Safe - It is safe to perform a demand.
///
///
/// By default none of the plug-in serializer code must succeed for partially trusted callers
///
[SecuritySafeCritical]
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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- CodeGroup.cs
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- Matrix.cs
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- SortDescription.cs
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- XmlSchemaImport.cs
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