Mutex.GetAccessControl メソッド
定義
重要
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名前付きミューテックスのアクセス制御セキュリティを表す MutexSecurity オブジェクトを取得します。
public:
System::Security::AccessControl::MutexSecurity ^ GetAccessControl();public System.Security.AccessControl.MutexSecurity GetAccessControl ();member this.GetAccessControl : unit -> System.Security.AccessControl.MutexSecurityPublic Function GetAccessControl () As MutexSecurity戻り値
名前付きミューテックスのアクセス制御セキュリティを表す MutexSecurity オブジェクト。
例外
現在の Mutex オブジェクトは名前付きシステム ミューテックスを表していますが、ユーザーに ReadPermissions がありません。
または
現在の Mutex オブジェクトは名前付きシステム ミューテックスを表しており、ReadPermissions で開かれませんでした。
例
次のコード例は、アクセス制御セキュリティを備えた名前付きミューテックスのクロスプロセス動作を示しています。 この例では、 メソッド オーバーロードを OpenExisting(String) 使用して、名前付きミューテックスの存在をテストします。
ミューテックスが存在しない場合は、ミューテックスを使用する権限を現在のユーザーに拒否する初期所有権とアクセス制御セキュリティを使用して作成されますが、ミューテックスに対する読み取りと変更のアクセス許可を付与します。
2 つのコマンド ウィンドウからコンパイルされた例を実行すると、2 番目のコピーは への OpenExisting(String)呼び出しでアクセス違反例外をスローします。 例外がキャッチされ、メソッドオーバーロードをOpenExisting(String, MutexRights)使用して、 メソッドと SetAccessControl メソッドを使用して、アクセス許可の読み取りと変更に必要な権限を持つミューテックスをGetAccessControl開きます。
アクセス許可が変更されると、ミューテックスは、それを入力して解放するために必要な権限で開かれます。 3 番目のコマンド ウィンドウからコンパイルされた例を実行すると、新しいアクセス許可を使用して実行されます。
using namespace System;
using namespace System::Threading;
using namespace System::Security::AccessControl;
using namespace System::Security::Permissions;
public ref class Example
{
public:
[SecurityPermissionAttribute(SecurityAction::Demand,Flags=SecurityPermissionFlag::UnmanagedCode)]
static void Main()
{
String^ mutexName = L"MutexExample4";
Mutex^ m = nullptr;
bool doesNotExist = false;
bool unauthorized = false;
// The value of this variable is set by the mutex
// constructor. It is true if the named system mutex was
// created, and false if the named mutex already existed.
//
bool mutexWasCreated = false;
// Attempt to open the named mutex.
try
{
// Open the mutex with (MutexRights.Synchronize |
// MutexRights.Modify), to enter and release the
// named mutex.
//
m = Mutex::OpenExisting( mutexName );
}
catch ( WaitHandleCannotBeOpenedException^ )
{
Console::WriteLine( L"Mutex does not exist." );
doesNotExist = true;
}
catch ( UnauthorizedAccessException^ ex )
{
Console::WriteLine( L"Unauthorized access: {0}", ex->Message );
unauthorized = true;
}
// There are three cases: (1) The mutex does not exist.
// (2) The mutex exists, but the current user doesn't
// have access. (3) The mutex exists and the user has
// access.
//
if ( doesNotExist )
{
// The mutex does not exist, so create it.
// Create an access control list (ACL) that denies the
// current user the right to enter or release the
// mutex, but allows the right to read and change
// security information for the mutex.
//
String^ user = String::Concat( Environment::UserDomainName, L"\\",
Environment::UserName );
MutexSecurity^ mSec = gcnew MutexSecurity;
MutexAccessRule^ rule = gcnew MutexAccessRule( user,
static_cast<MutexRights>(
MutexRights::Synchronize |
MutexRights::Modify),
AccessControlType::Deny );
mSec->AddAccessRule( rule );
rule = gcnew MutexAccessRule( user,
static_cast<MutexRights>(
MutexRights::ReadPermissions |
MutexRights::ChangePermissions),
AccessControlType::Allow );
mSec->AddAccessRule( rule );
// Create a Mutex object that represents the system
// mutex named by the constant 'mutexName', with
// initial ownership for this thread, and with the
// specified security access. The Boolean value that
// indicates creation of the underlying system object
// is placed in mutexWasCreated.
//
m = gcnew Mutex( true,mutexName, mutexWasCreated,mSec );
// If the named system mutex was created, it can be
// used by the current instance of this program, even
// though the current user is denied access. The current
// program owns the mutex. Otherwise, exit the program.
//
if ( mutexWasCreated )
{
Console::WriteLine( L"Created the mutex." );
}
else
{
Console::WriteLine( L"Unable to create the mutex." );
return;
}
}
else if ( unauthorized )
{
// Open the mutex to read and change the access control
// security. The access control security defined above
// allows the current user to do this.
//
try
{
m = Mutex::OpenExisting( mutexName,
static_cast<MutexRights>(
MutexRights::ReadPermissions |
MutexRights::ChangePermissions) );
// Get the current ACL. This requires
// MutexRights.ReadPermissions.
MutexSecurity^ mSec = m->GetAccessControl();
String^ user = String::Concat( Environment::UserDomainName,
L"\\", Environment::UserName );
// First, the rule that denied the current user
// the right to enter and release the mutex must
// be removed.
MutexAccessRule^ rule = gcnew MutexAccessRule( user,
static_cast<MutexRights>(
MutexRights::Synchronize |
MutexRights::Modify),
AccessControlType::Deny );
mSec->RemoveAccessRule( rule );
// Now grant the user the correct rights.
//
rule = gcnew MutexAccessRule( user,
static_cast<MutexRights>(
MutexRights::Synchronize |
MutexRights::Modify),
AccessControlType::Allow );
mSec->AddAccessRule( rule );
// Update the ACL. This requires
// MutexRights.ChangePermissions.
m->SetAccessControl( mSec );
Console::WriteLine( L"Updated mutex security." );
// Open the mutex with (MutexRights.Synchronize
// | MutexRights.Modify), the rights required to
// enter and release the mutex.
//
m = Mutex::OpenExisting( mutexName );
}
catch ( UnauthorizedAccessException^ ex )
{
Console::WriteLine(
L"Unable to change permissions: {0}", ex->Message );
return;
}
}
// If this program created the mutex, it already owns
// the mutex.
//
if ( !mutexWasCreated )
{
// Enter the mutex, and hold it until the program
// exits.
//
try
{
Console::WriteLine( L"Wait for the mutex." );
m->WaitOne();
Console::WriteLine( L"Entered the mutex." );
}
catch ( UnauthorizedAccessException^ ex )
{
Console::WriteLine( L"Unauthorized access: {0}",
ex->Message );
}
}
Console::WriteLine( L"Press the Enter key to exit." );
Console::ReadLine();
m->ReleaseMutex();
m->Dispose();
}
};
int main()
{
Example::Main();
}
using System;
using System.Threading;
using System.Security.AccessControl;
internal class Example
{
internal static void Main()
{
const string mutexName = "MutexExample4";
Mutex m = null;
bool doesNotExist = false;
bool unauthorized = false;
// The value of this variable is set by the mutex
// constructor. It is true if the named system mutex was
// created, and false if the named mutex already existed.
//
bool mutexWasCreated = false;
// Attempt to open the named mutex.
try
{
// Open the mutex with (MutexRights.Synchronize |
// MutexRights.Modify), to enter and release the
// named mutex.
//
m = Mutex.OpenExisting(mutexName);
}
catch(WaitHandleCannotBeOpenedException)
{
Console.WriteLine("Mutex does not exist.");
doesNotExist = true;
}
catch(UnauthorizedAccessException ex)
{
Console.WriteLine("Unauthorized access: {0}", ex.Message);
unauthorized = true;
}
// There are three cases: (1) The mutex does not exist.
// (2) The mutex exists, but the current user doesn't
// have access. (3) The mutex exists and the user has
// access.
//
if (doesNotExist)
{
// The mutex does not exist, so create it.
// Create an access control list (ACL) that denies the
// current user the right to enter or release the
// mutex, but allows the right to read and change
// security information for the mutex.
//
string user = Environment.UserDomainName + "\\"
+ Environment.UserName;
var mSec = new MutexSecurity();
MutexAccessRule rule = new MutexAccessRule(user,
MutexRights.Synchronize | MutexRights.Modify,
AccessControlType.Deny);
mSec.AddAccessRule(rule);
rule = new MutexAccessRule(user,
MutexRights.ReadPermissions | MutexRights.ChangePermissions,
AccessControlType.Allow);
mSec.AddAccessRule(rule);
// Create a Mutex object that represents the system
// mutex named by the constant 'mutexName', with
// initial ownership for this thread, and with the
// specified security access. The Boolean value that
// indicates creation of the underlying system object
// is placed in mutexWasCreated.
//
m = new Mutex(true, mutexName, out mutexWasCreated, mSec);
// If the named system mutex was created, it can be
// used by the current instance of this program, even
// though the current user is denied access. The current
// program owns the mutex. Otherwise, exit the program.
//
if (mutexWasCreated)
{
Console.WriteLine("Created the mutex.");
}
else
{
Console.WriteLine("Unable to create the mutex.");
return;
}
}
else if (unauthorized)
{
// Open the mutex to read and change the access control
// security. The access control security defined above
// allows the current user to do this.
//
try
{
m = Mutex.OpenExisting(mutexName,
MutexRights.ReadPermissions | MutexRights.ChangePermissions);
// Get the current ACL. This requires
// MutexRights.ReadPermissions.
MutexSecurity mSec = m.GetAccessControl();
string user = Environment.UserDomainName + "\\"
+ Environment.UserName;
// First, the rule that denied the current user
// the right to enter and release the mutex must
// be removed.
MutexAccessRule rule = new MutexAccessRule(user,
MutexRights.Synchronize | MutexRights.Modify,
AccessControlType.Deny);
mSec.RemoveAccessRule(rule);
// Now grant the user the correct rights.
//
rule = new MutexAccessRule(user,
MutexRights.Synchronize | MutexRights.Modify,
AccessControlType.Allow);
mSec.AddAccessRule(rule);
// Update the ACL. This requires
// MutexRights.ChangePermissions.
m.SetAccessControl(mSec);
Console.WriteLine("Updated mutex security.");
// Open the mutex with (MutexRights.Synchronize
// | MutexRights.Modify), the rights required to
// enter and release the mutex.
//
m = Mutex.OpenExisting(mutexName);
}
catch(UnauthorizedAccessException ex)
{
Console.WriteLine("Unable to change permissions: {0}",
ex.Message);
return;
}
}
// If this program created the mutex, it already owns
// the mutex.
//
if (!mutexWasCreated)
{
// Enter the mutex, and hold it until the program
// exits.
//
try
{
Console.WriteLine("Wait for the mutex.");
m.WaitOne();
Console.WriteLine("Entered the mutex.");
}
catch(UnauthorizedAccessException ex)
{
Console.WriteLine("Unauthorized access: {0}", ex.Message);
}
}
Console.WriteLine("Press the Enter key to exit.");
Console.ReadLine();
m.ReleaseMutex();
m.Dispose();
}
}
Imports System.Threading
Imports System.Security.AccessControl
Friend Class Example
<MTAThread> _
Friend Shared Sub Main()
Const mutexName As String = "MutexExample4"
Dim m As Mutex = Nothing
Dim doesNotExist as Boolean = False
Dim unauthorized As Boolean = False
' The value of this variable is set by the mutex
' constructor. It is True if the named system mutex was
' created, and False if the named mutex already existed.
'
Dim mutexWasCreated As Boolean
' Attempt to open the named mutex.
Try
' Open the mutex with (MutexRights.Synchronize Or
' MutexRights.Modify), to enter and release the
' named mutex.
'
m = Mutex.OpenExisting(mutexName)
Catch ex As WaitHandleCannotBeOpenedException
Console.WriteLine("Mutex does not exist.")
doesNotExist = True
Catch ex As UnauthorizedAccessException
Console.WriteLine("Unauthorized access: {0}", ex.Message)
unauthorized = True
End Try
' There are three cases: (1) The mutex does not exist.
' (2) The mutex exists, but the current user doesn't
' have access. (3) The mutex exists and the user has
' access.
'
If doesNotExist Then
' The mutex does not exist, so create it.
' Create an access control list (ACL) that denies the
' current user the right to enter or release the
' mutex, but allows the right to read and change
' security information for the mutex.
'
Dim user As String = Environment.UserDomainName _
& "\" & Environment.UserName
Dim mSec As New MutexSecurity()
Dim rule As New MutexAccessRule(user, _
MutexRights.Synchronize Or MutexRights.Modify, _
AccessControlType.Deny)
mSec.AddAccessRule(rule)
rule = New MutexAccessRule(user, _
MutexRights.ReadPermissions Or _
MutexRights.ChangePermissions, _
AccessControlType.Allow)
mSec.AddAccessRule(rule)
' Create a Mutex object that represents the system
' mutex named by the constant 'mutexName', with
' initial ownership for this thread, and with the
' specified security access. The Boolean value that
' indicates creation of the underlying system object
' is placed in mutexWasCreated.
'
m = New Mutex(True, mutexName, mutexWasCreated, mSec)
' If the named system mutex was created, it can be
' used by the current instance of this program, even
' though the current user is denied access. The current
' program owns the mutex. Otherwise, exit the program.
'
If mutexWasCreated Then
Console.WriteLine("Created the mutex.")
Else
Console.WriteLine("Unable to create the mutex.")
Return
End If
ElseIf unauthorized Then
' Open the mutex to read and change the access control
' security. The access control security defined above
' allows the current user to do this.
'
Try
m = Mutex.OpenExisting(mutexName, _
MutexRights.ReadPermissions Or _
MutexRights.ChangePermissions)
' Get the current ACL. This requires
' MutexRights.ReadPermissions.
Dim mSec As MutexSecurity = m.GetAccessControl()
Dim user As String = Environment.UserDomainName _
& "\" & Environment.UserName
' First, the rule that denied the current user
' the right to enter and release the mutex must
' be removed.
Dim rule As New MutexAccessRule(user, _
MutexRights.Synchronize Or MutexRights.Modify, _
AccessControlType.Deny)
mSec.RemoveAccessRule(rule)
' Now grant the user the correct rights.
'
rule = New MutexAccessRule(user, _
MutexRights.Synchronize Or MutexRights.Modify, _
AccessControlType.Allow)
mSec.AddAccessRule(rule)
' Update the ACL. This requires
' MutexRights.ChangePermissions.
m.SetAccessControl(mSec)
Console.WriteLine("Updated mutex security.")
' Open the mutex with (MutexRights.Synchronize
' Or MutexRights.Modify), the rights required to
' enter and release the mutex.
'
m = Mutex.OpenExisting(mutexName)
Catch ex As UnauthorizedAccessException
Console.WriteLine("Unable to change permissions: {0}", _
ex.Message)
Return
End Try
End If
' If this program created the mutex, it already owns
' the mutex.
'
If Not mutexWasCreated Then
' Enter the mutex, and hold it until the program
' exits.
'
Try
Console.WriteLine("Wait for the mutex.")
m.WaitOne()
Console.WriteLine("Entered the mutex.")
Catch ex As UnauthorizedAccessException
Console.WriteLine("Unauthorized access: {0}", _
ex.Message)
End Try
End If
Console.WriteLine("Press the Enter key to exit.")
Console.ReadLine()
m.ReleaseMutex()
m.Dispose()
End Sub
End Class
注釈
メソッドはGetAccessControl、次のフラグの組み合わせを使用して (ビットごとの OR 操作を使用して結合)、、AccessControlSections.Owner、および AccessControlSections.Groupのアクセス許可AccessControlSections.Accessを検索します。
ユーザーはこのメソッドを呼び出す必要 MutexRights.ReadPermissions があり、ミューテックスは で MutexRights.ReadPermissions開かれている必要があります。
Note
.NET Core と .NET 5 以降では、同等のメソッドは です GetAccessControl。
適用対象
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