X509KeyUsageExtension 类

定义

定义 X.509 证书中所包含的密钥的用法。 此类不能被继承。

public ref class X509KeyUsageExtension sealed : System::Security::Cryptography::X509Certificates::X509Extension
public sealed class X509KeyUsageExtension : System.Security.Cryptography.X509Certificates.X509Extension
type X509KeyUsageExtension = class
    inherit X509Extension
Public NotInheritable Class X509KeyUsageExtension
Inherits X509Extension
继承
X509KeyUsageExtension

示例

下面的代码示例演示如何打开用户的个人证书存储,并显示有关存储中每个证书的信息。 此示例使用 X509KeyUsageExtension 类显示信息。

#using <System.dll>
#using <system.security.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::X509Certificates;
int main()
{
   try
   {
      X509Store^ store = gcnew X509Store( L"MY",StoreLocation::CurrentUser );
      store->Open( static_cast<OpenFlags>(OpenFlags::ReadOnly | OpenFlags::OpenExistingOnly) );
      X509Certificate2Collection^ collection = dynamic_cast<X509Certificate2Collection^>(store->Certificates);
      for ( int i = 0; i < collection->Count; i++ )
      {
         System::Collections::IEnumerator^ myEnum = collection[ i ]->Extensions->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            X509Extension^ extension = safe_cast<X509Extension^>(myEnum->Current);
            Console::WriteLine( L"{0}({1})", extension->Oid->FriendlyName, extension->Oid->Value );
            if ( extension->Oid->FriendlyName == L"Key Usage" )
            {
               X509KeyUsageExtension^ ext = dynamic_cast<X509KeyUsageExtension^>(extension);
               Console::WriteLine( ext->KeyUsages );
            }
            if ( extension->Oid->FriendlyName == L"Basic Constraints" )
            {
               X509BasicConstraintsExtension^ ext = dynamic_cast<X509BasicConstraintsExtension^>(extension);
               Console::WriteLine( ext->CertificateAuthority );
               Console::WriteLine( ext->HasPathLengthConstraint );
               Console::WriteLine( ext->PathLengthConstraint );
            }
            if ( extension->Oid->FriendlyName == L"Subject Key Identifier" )
            {
               X509SubjectKeyIdentifierExtension^ ext = dynamic_cast<X509SubjectKeyIdentifierExtension^>(extension);
               Console::WriteLine( ext->SubjectKeyIdentifier );
            }
            if ( extension->Oid->FriendlyName == L"Enhanced Key Usage" )
            {
               X509EnhancedKeyUsageExtension^ ext = dynamic_cast<X509EnhancedKeyUsageExtension^>(extension);
               OidCollection^ oids = ext->EnhancedKeyUsages;
               System::Collections::IEnumerator^ myEnum1 = oids->GetEnumerator();
               while ( myEnum1->MoveNext() )
               {
                  Oid^ oid = safe_cast<Oid^>(myEnum1->Current);
                  Console::WriteLine( L"{0}({1})", oid->FriendlyName, oid->Value );
               }
            }
         }

      }
      store->Close();
   }
   catch ( CryptographicException^ ) 
   {
      Console::WriteLine( L"Information could not be written out for this certificate." );
   }

}
using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

public class CertSelect
{
    public static void Main()
    {
        try
        {
            X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
            store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);

            X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
            for (int i = 0; i < collection.Count; i++)
            {
                foreach (X509Extension extension in collection[i].Extensions)
                {
                    Console.WriteLine(extension.Oid.FriendlyName + "(" + extension.Oid.Value + ")");

                    if (extension.Oid.FriendlyName == "Key Usage")
                    {
                        X509KeyUsageExtension ext = (X509KeyUsageExtension)extension;
                        Console.WriteLine(ext.KeyUsages);
                    }

                    if (extension.Oid.FriendlyName == "Basic Constraints")
                    {
                        X509BasicConstraintsExtension ext = (X509BasicConstraintsExtension)extension;
                        Console.WriteLine(ext.CertificateAuthority);
                        Console.WriteLine(ext.HasPathLengthConstraint);
                        Console.WriteLine(ext.PathLengthConstraint);
                    }

                    if (extension.Oid.FriendlyName == "Subject Key Identifier")
                    {
                        X509SubjectKeyIdentifierExtension ext = (X509SubjectKeyIdentifierExtension)extension;
                        Console.WriteLine(ext.SubjectKeyIdentifier);
                    }

                    if (extension.Oid.FriendlyName == "Enhanced Key Usage")
                    {
                        X509EnhancedKeyUsageExtension ext = (X509EnhancedKeyUsageExtension)extension;
                        OidCollection oids = ext.EnhancedKeyUsages;
                        foreach (Oid oid in oids)
                        {
                            Console.WriteLine(oid.FriendlyName + "(" + oid.Value + ")");
                        }
                    }
                }
            }
            store.Close();
        }
        catch (CryptographicException)
        {
            Console.WriteLine("Information could not be written out for this certificate.");
        }
    }
}
Imports System.Security.Cryptography
Imports System.Security.Cryptography.X509Certificates



Module CertSelect

    Sub Main()
        Try
            Dim store As New X509Store("MY", StoreLocation.CurrentUser)
            store.Open(OpenFlags.ReadOnly Or OpenFlags.OpenExistingOnly)

            Dim collection As X509Certificate2Collection = CType(store.Certificates, X509Certificate2Collection)
            For i As Integer = 0 To collection.Count - 1
                Dim extension As X509Extension
                For Each extension In collection(i).Extensions
                    Console.WriteLine(extension.Oid.FriendlyName + "(" + extension.Oid.Value + ")")


                    If extension.Oid.FriendlyName = "Key Usage" Then
                        Dim ext As X509KeyUsageExtension = CType(extension, X509KeyUsageExtension)
                        Console.WriteLine(ext.KeyUsages)
                    End If

                    If extension.Oid.FriendlyName = "Basic Constraints" Then
                        Dim ext As X509BasicConstraintsExtension = CType(extension, X509BasicConstraintsExtension)
                        Console.WriteLine(ext.CertificateAuthority)
                        Console.WriteLine(ext.HasPathLengthConstraint)
                        Console.WriteLine(ext.PathLengthConstraint)
                    End If

                    If extension.Oid.FriendlyName = "Subject Key Identifier" Then
                        Dim ext As X509SubjectKeyIdentifierExtension = CType(extension, X509SubjectKeyIdentifierExtension)
                        Console.WriteLine(ext.SubjectKeyIdentifier)
                    End If

                    If extension.Oid.FriendlyName = "Enhanced Key Usage" Then
                        Dim ext As X509EnhancedKeyUsageExtension = CType(extension, X509EnhancedKeyUsageExtension)
                        Dim oids As OidCollection = ext.EnhancedKeyUsages
                        Dim oid As Oid
                        For Each oid In oids
                            Console.WriteLine(oid.FriendlyName + "(" + oid.Value + ")")
                        Next oid
                    End If
                Next extension
            Next i
            store.Close()
        Catch
            Console.WriteLine("Information could not be written out for this certificate.")
        End Try

    End Sub
End Module

注解

X509KeyUsageExtension 类使用枚举中的 X509KeyUsageFlags 标志来定义或确定密钥用法。

构造函数

X509KeyUsageExtension()

初始化 X509KeyUsageExtension 类的新实例。

X509KeyUsageExtension(AsnEncodedData, Boolean)

使用 X509KeyUsageExtension 对象和一个标识扩展是否重要的值初始化 AsnEncodedData 类的新实例。

X509KeyUsageExtension(X509KeyUsageFlags, Boolean)

使用指定的 X509KeyUsageExtension 值和一个标识扩展是否重要的值初始化 X509KeyUsageFlags 类的新实例。

属性

Critical

获取一个指示扩展是否必不可少的布尔值。

(继承自 X509Extension)
KeyUsages

获取与证书关联的密钥用法标志。

Oid

获取或设置 Oid 对象的 AsnEncodedData 值。

(继承自 AsnEncodedData)
RawData

获取或设置以字节数组表示的 Abstract Syntax Notation One (ASN.1) 编码数据。

(继承自 AsnEncodedData)

方法

CopyFrom(AsnEncodedData)

使用 AsnEncodedData 对象初始化 X509KeyUsageExtension 类的新实例。

Equals(Object)

确定指定对象是否等于当前对象。

(继承自 Object)
Format(Boolean)

将 Abstract Syntax Notation One (ASN.1) 编码数据的格式化版本作为字符串返回。

(继承自 AsnEncodedData)
GetHashCode()

作为默认哈希函数。

(继承自 Object)
GetType()

获取当前实例的 Type

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。

(继承自 Object)
ToString()

返回表示当前对象的字符串。

(继承自 Object)

适用于