SecurityElement Klas

Definitie

public ref class SecurityElement sealed

[System.Serializable]
public sealed class SecurityElement

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class SecurityElement

public sealed class SecurityElement

[<System.Serializable>]
type SecurityElement = class

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type SecurityElement = class

type SecurityElement = class

Public NotInheritable Class SecurityElement

Overname

Object

SecurityElement

Kenmerken

SerializableAttribute ComVisibleAttribute

Voorbeelden

In het volgende voorbeeld ziet u het gebruik van leden van de SecurityElement klasse.

using System;
using System.Security;
using System.Collections;

class SecurityElementMembers
{
    [STAThread]
    static void Main(string[] args)
    {
        SecurityElement xmlRootElement =
            new SecurityElement("RootTag", "XML security tree");

        AddAttribute(xmlRootElement,"creationdate",DateTime.Now.ToString());
        AddChildElement(xmlRootElement,"destroytime",
            DateTime.Now.AddSeconds(1.0).ToString());

        SecurityElement windowsRoleElement =
            new SecurityElement("WindowsMembership.WindowsRole");

        windowsRoleElement.AddAttribute("version","1.00");

        // Add a child element and a creationdate attribute.
        AddChildElement(windowsRoleElement,"BabyElement",
            "This is a child element");
        AddAttribute(windowsRoleElement,"creationdate",
            DateTime.Now.ToString());

        xmlRootElement.AddChild(windowsRoleElement);

        CompareAttributes(xmlRootElement, "creationdate");
        ConvertToHashTable(xmlRootElement);

        DisplaySummary(xmlRootElement);

        // Determine if the security element is too old to keep.
        xmlRootElement = DestroyTree(xmlRootElement);
        if (xmlRootElement != null)
        {
            string elementInXml = xmlRootElement.ToString();
            Console.WriteLine(elementInXml);
        }

        Console.WriteLine("This sample completed successfully; " +
            "press Enter to exit.");
        Console.ReadLine();
    }

    // Add an attribute to the specified security element.
    private static SecurityElement AddAttribute(
        SecurityElement xmlElement,
        string attributeName,
        string attributeValue)
    {
        if (xmlElement != null)
        {
            // Verify that the attribute name and value are valid XML formats.
            if (SecurityElement.IsValidAttributeName(attributeName) &&
                SecurityElement.IsValidAttributeValue(attributeValue))
            {
                // Add the attribute to the security element.
                xmlElement.AddAttribute(attributeName, attributeValue);
            }
        }
        return xmlElement;
    }

    // Add a child element to the specified security element.
    private static SecurityElement AddChildElement(
        SecurityElement parentElement,
        string tagName,
        string tagText)
    {
        if (parentElement != null)
        {
            // Ensure that the tag text is in valid XML format.
            if (!SecurityElement.IsValidText(tagText))
            {
                // Replace invalid text with valid XML text
                // to enforce proper XML formatting.
                tagText = SecurityElement.Escape(tagText);
            }

            // Determine whether the tag is in valid XML format.
            if (SecurityElement.IsValidTag(tagName))
            {
                SecurityElement childElement;
                childElement = parentElement.SearchForChildByTag(tagName);

                if (childElement != null)
                {
                    String elementText;
                    elementText = parentElement.SearchForTextOfTag(tagName);

                    if (!elementText.Equals(tagText))
                    {
                        // Add child element to the parent security element.
                        parentElement.AddChild(
                            new SecurityElement(tagName, tagText));
                    }
                }
                else
                {
                    // Add child element to the parent security element.
                    parentElement.AddChild(
                        new SecurityElement(tagName, tagText));
                }
            }
        }
        return parentElement;
    }

    // Create and display a summary sentence
    // about the specified security element.
    private static void DisplaySummary(SecurityElement xmlElement)
    {
        // Retrieve tag name for the security element.
        string xmlTreeName = xmlElement.Tag.ToString();

        // Retrieve tag text for the security element.
        string xmlTreeDescription = xmlElement.Text;

        // Retrieve value of the creationdate attribute.
        string xmlCreationDate = xmlElement.Attribute("creationdate");

        // Retrieve the number of children under the security element.
        string childrenCount = xmlElement.Children.Count.ToString();

        string outputMessage = "The security XML tree named " + xmlTreeName;
        outputMessage += "(" + xmlTreeDescription + ")";
        outputMessage += " was created on " + xmlCreationDate + " and ";
        outputMessage += "contains " + childrenCount + " child elements.";

        Console.WriteLine(outputMessage);
    }

    // Compare the first two occurrences of an attribute
    // in the specified security element.
    private static void CompareAttributes(
        SecurityElement xmlElement, string attributeName)
    {
        // Create a hash table containing the security element's attributes.
        Hashtable attributeKeys = xmlElement.Attributes;
        string attributeValue = attributeKeys[attributeName].ToString();

        foreach(SecurityElement xmlChild in xmlElement.Children)
        {
            if (attributeValue.Equals(xmlChild.Attribute(attributeName)))
            {
                // The security elements were created at the exact same time.
            }
        }
    }

    // Convert the contents of the specified security element
    // to hash codes stored in a hash table.
    private static void ConvertToHashTable(SecurityElement xmlElement)
    {
        // Create a hash table to hold hash codes of the security elements.
        Hashtable xmlAsHash = new Hashtable();
        int rootIndex = xmlElement.GetHashCode();
        xmlAsHash.Add(rootIndex, "root");

        int parentNum = 0;

        foreach(SecurityElement xmlParent in xmlElement.Children)
        {
            parentNum++;
            xmlAsHash.Add(xmlParent.GetHashCode(), "parent" + parentNum);
            if ((xmlParent.Children != null) &&
                (xmlParent.Children.Count > 0))
            {
                int childNum = 0;
                foreach(SecurityElement xmlChild in xmlParent.Children)
                {
                    childNum++;
                    xmlAsHash.Add(xmlChild.GetHashCode(), "child" + childNum);
                }
            }
        }
    }

    // Delete the specified security element if the current time is past
    // the time stored in the destroytime tag.
    private static SecurityElement DestroyTree(SecurityElement xmlElement)
    {
        SecurityElement localXmlElement = xmlElement;
        SecurityElement destroyElement =
            localXmlElement.SearchForChildByTag("destroytime");

        // Verify that a destroytime tag exists.
        if (localXmlElement.SearchForChildByTag("destroytime") != null)
        {
            // Retrieve the destroytime text to get the time
            // the tree can be destroyed.
            string storedDestroyTime =
                localXmlElement.SearchForTextOfTag("destroytime");

            DateTime destroyTime = DateTime.Parse(storedDestroyTime);
            if (DateTime.Now > destroyTime)
            {
                localXmlElement = null;
                Console.WriteLine("The XML security tree has been deleted.");
            }
        }

        // Verify that xmlElement is of type SecurityElement.
        if (xmlElement.GetType().Equals(
            typeof(System.Security.SecurityElement)))
        {
            // Determine whether the localXmlElement object
            // differs from xmlElement.
            if (xmlElement.Equals(localXmlElement))
            {
                // Verify that the tags, attributes and children of the
                // two security elements are identical.
                if (xmlElement.Equal(localXmlElement))
                {
                    // Return the original security element.
                    return xmlElement;
                }
            }
        }

        // Return the modified security element.
        return localXmlElement;
    }
}
//
// This sample produces the following output:
//
// The security XML tree named RootTag(XML security tree)
// was created on 2/23/2004 1:23:00 PM and contains 2 child elements.
//<RootTag creationdate="2/23/2004 1:23:00 PM">XML security tree
//   <destroytime>2/23/2004 1:23:01 PM</destroytime>
//   <WindowsMembership.WindowsRole version="1.00"
//                                  creationdate="2/23/2004 1:23:00 PM">
//      <BabyElement>This is a child element.</BabyElement>
//
//This sample completed successfully; press Exit to continue.

Imports System.Security
Imports System.Collections



Class SecurityElementMembers

    <STAThread()> _
    Shared Sub Main(ByVal args() As String)
        Dim xmlRootElement As New SecurityElement("RootTag", "XML security tree")
        AddAttribute(xmlRootElement, "creationdate", DateTime.Now.ToString())
        AddChildElement(xmlRootElement, "destroytime", DateTime.Now.AddSeconds(1.0).ToString())

        Dim windowsRoleElement As New SecurityElement("WindowsMembership.WindowsRole")
        windowsRoleElement.AddAttribute("version", "1.00")
        ' Add a child element and a creationdate attribute.
        AddChildElement(windowsRoleElement, "BabyElement", "This is a child element")
        AddAttribute(windowsRoleElement, "creationdate", DateTime.Now.ToString())

        xmlRootElement.AddChild(windowsRoleElement)
        CompareAttributes(xmlRootElement, "creationdate")
        ConvertToHashTable(xmlRootElement)

        DisplaySummary(xmlRootElement)

        ' Determine if the security element is too old to keep.
        xmlRootElement = DestroyTree(xmlRootElement)
        If Not (xmlRootElement Is Nothing) Then
            Dim elementInXml As String = xmlRootElement.ToString()
            Console.WriteLine(elementInXml)
        End If

        Console.WriteLine("This sample completed successfully; " + "press Enter to exit.")
        Console.ReadLine()

    End Sub


    ' Add an attribute to the specified security element.
    Private Shared Function AddAttribute(ByVal xmlElement As SecurityElement, ByVal attributeName As String, ByVal attributeValue As String) As SecurityElement
        If Not (xmlElement Is Nothing) Then
            ' Verify that the attribute name and value are valid XML formats.
            If SecurityElement.IsValidAttributeName(attributeName) AndAlso SecurityElement.IsValidAttributeValue(attributeValue) Then
                ' Add the attribute to the security element.
                xmlElement.AddAttribute(attributeName, attributeValue)
            End If
        End If
        Return xmlElement

    End Function 'AddAttribute


    ' Add a child element to the specified security element.
    Private Shared Function AddChildElement(ByVal parentElement As SecurityElement, ByVal tagName As String, ByVal tagText As String) As SecurityElement
        If Not (parentElement Is Nothing) Then
            ' Ensure that the tag text is in valid XML format.
            If Not SecurityElement.IsValidText(tagText) Then
                ' Replace invalid text with valid XML text 
                ' to enforce proper XML formatting.
                tagText = SecurityElement.Escape(tagText)
            End If

            ' Determine whether the tag is in valid XML format.
            If SecurityElement.IsValidTag(tagName) Then
                Dim childElement As SecurityElement
                childElement = parentElement.SearchForChildByTag(tagName)
                If Not (childElement Is Nothing) Then
                    Dim elementText As String
                    elementText = parentElement.SearchForTextOfTag(tagName)
                    If Not elementText.Equals(tagText) Then
                        ' Add child element to the parent security element.
                        parentElement.AddChild(New SecurityElement(tagName, tagText))
                    End If
                Else
                    ' Add child element to the parent security element.
                    parentElement.AddChild(New SecurityElement(tagName, tagText))
                End If
            End If
        End If
        Return parentElement

    End Function 'AddChildElement


    ' Create and display a summary sentence 
    ' about the specified security element.
    Private Shared Sub DisplaySummary(ByVal xmlElement As SecurityElement)
        ' Retrieve tag name for the security element.
        Dim xmlTreeName As String = xmlElement.Tag.ToString()
        ' Retrieve tag text for the security element.
        Dim xmlTreeDescription As String = xmlElement.Text
        ' Retrieve value of the creationdate attribute.
        Dim xmlCreationDate As String = xmlElement.Attribute("creationdate")
        ' Retrieve the number of children under the security element.
        Dim childrenCount As String = xmlElement.Children.Count.ToString()
        Dim outputMessage As String = "The security XML tree named " + xmlTreeName
        outputMessage += "(" + xmlTreeDescription + ")"
        outputMessage += " was created on " + xmlCreationDate + " and "
        outputMessage += "contains " + childrenCount + " child elements."

        Console.WriteLine(outputMessage)

    End Sub


    ' Compare the first two occurrences of an attribute 
    ' in the specified security element.
    Private Shared Sub CompareAttributes(ByVal xmlElement As SecurityElement, ByVal attributeName As String)
        ' Create a hash table containing the security element's attributes.
        Dim attributeKeys As Hashtable = xmlElement.Attributes
        Dim attributeValue As String = attributeKeys(attributeName).ToString()
        Dim xmlChild As SecurityElement
        For Each xmlChild In xmlElement.Children
            If attributeValue.Equals(xmlChild.Attribute(attributeName)) Then
            End If
        Next xmlChild
        ' The security elements were created at the exact same time.
    End Sub


    ' Convert the contents of the specified security element 
    ' to hash codes stored in a hash table.
    Private Shared Sub ConvertToHashTable(ByVal xmlElement As SecurityElement)
        ' Create a hash table to hold hash codes of the security elements.
        Dim xmlAsHash As New Hashtable()
        Dim rootIndex As Integer = xmlElement.GetHashCode()
        xmlAsHash.Add(rootIndex, "root")
        Dim parentNum As Integer = 0

        Dim xmlParent As SecurityElement
        For Each xmlParent In xmlElement.Children
            parentNum += 1
            xmlAsHash.Add(xmlParent.GetHashCode(), "parent" + parentNum.ToString())
            If Not (xmlParent.Children Is Nothing) AndAlso xmlParent.Children.Count > 0 Then
                Dim childNum As Integer = 0
                Dim xmlChild As SecurityElement
                For Each xmlChild In xmlParent.Children
                    childNum += 1
                    xmlAsHash.Add(xmlChild.GetHashCode(), "child" + childNum.ToString())
                Next xmlChild
            End If
        Next xmlParent

    End Sub


    ' Delete the specified security element if the current time is past
    ' the time stored in the destroytime tag.
    Private Shared Function DestroyTree(ByVal xmlElement As SecurityElement) As SecurityElement
        Dim localXmlElement As SecurityElement = xmlElement
        Dim destroyElement As SecurityElement = localXmlElement.SearchForChildByTag("destroytime")

        ' Verify that a destroytime tag exists.
        If Not (localXmlElement.SearchForChildByTag("destroytime") Is Nothing) Then
            ' Retrieve the destroytime text to get the time 
            ' the tree can be destroyed.
            Dim storedDestroyTime As String = localXmlElement.SearchForTextOfTag("destroytime")
            Dim destroyTime As DateTime = DateTime.Parse(storedDestroyTime)
            If DateTime.Now > destroyTime Then
                localXmlElement = Nothing
                Console.WriteLine("The XML security tree has been deleted.")
            End If
        End If

        ' Verify that xmlElement is of type SecurityElement.
        If xmlElement.GetType().Equals(GetType(System.Security.SecurityElement)) Then
            ' Determine whether the localXmlElement object 
            ' differs from xmlElement.
            If xmlElement.Equals(localXmlElement) Then
                ' Verify that the tags, attributes and children of the
                ' two security elements are identical.
                If xmlElement.Equal(localXmlElement) Then
                    ' Return the original security element.
                    Return xmlElement
                End If
            End If
        End If

        ' Return the modified security element.
        Return localXmlElement

    End Function 'DestroyTree
End Class
'
' This sample produces the following output:
' 
' The security XML tree named RootTag(XML security tree) 
' was created on 2/23/2004 1:23:00 PM and contains 2 child elements.
'<RootTag creationdate="2/23/2004 1:23:00 PM">XML security tree
'   <destroytime>2/23/2004 1:23:01 PM</destroytime>
'   <WindowsMembership.WindowsRole version="1.00"
'                                  creationdate="2/23/2004 1:23:00 PM">
'      <BabyElement>This is a child element.</BabyElement>
'
'This sample completed successfully; press Exit to continue.

Opmerkingen

Deze klasse is bedoeld als een lichtgewicht implementatie van een eenvoudig XML-objectmodel voor gebruik in het beveiligingssysteem en niet voor gebruik als een algemeen XML-objectmodel. In deze documentatie wordt ervan uitgegaan dat u basiskennis van XML hebt.

Het eenvoudige XML-objectmodel voor een element bestaat uit de volgende onderdelen:

• De tag is de elementnaam.

• De kenmerken zijn nul of meer naam-waardekenmerkparen op het element.

• De onderliggende elementen zijn nul of meer elementen genest binnen <tag> en </tag>.

Het wordt sterk aangeraden dat xml-weergave op basis van kenmerken wordt gebruikt om beveiligingselementen en hun waarden uit te drukken. Dit betekent dat eigenschappen van een element worden uitgedrukt als kenmerken en eigenschapswaarden worden uitgedrukt als kenmerkwaarden. Vermijd het nesten van tekst in tags. Voor elke <tag>text</tag> weergave is een weergave van het type <tag value="text"/> meestal beschikbaar. Het gebruik van deze op kenmerken gebaseerde XML-weergave verhoogt de leesbaarheid en maakt eenvoudige WMI-overdracht van de resulterende XML-serialisatie mogelijk.

Een kenmerknaam moet één teken of langer zijn en mag niet zijn null. Als op elementen gebaseerde waardeweergave wordt gebruikt, worden elementen met een tekenreeks die in het formulier wordt null weergegeven. Anders wordt tekst gescheiden door de <tag> en </tag> tokens.<tag/> Beide formulieren kunnen worden gecombineerd met kenmerken, die worden weergegeven als ze aanwezig zijn.

De tags, kenmerken en tekst van elementen, indien aanwezig, zijn altijd hoofdlettergevoelig. Het XML-formulier bevat waar nodig aanhalingstekens en escapes. Tekenreekswaarden die tekens bevatten die ongeldig zijn voor gebruik in XML-resultaten in een ArgumentException. Deze regels zijn van toepassing op alle eigenschappen en methoden.