AsymmetricAlgorithm 類別

定義

表示抽象基底類別,非對稱演算法的所有實作都必須從它繼承。Represents the abstract base class from which all implementations of asymmetric algorithms must inherit.

public ref class AsymmetricAlgorithm abstract : IDisposable
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class AsymmetricAlgorithm : IDisposable
type AsymmetricAlgorithm = class
    interface IDisposable
Public MustInherit Class AsymmetricAlgorithm
Implements IDisposable
繼承
AsymmetricAlgorithm
衍生
屬性
實作

範例

下列程式碼範例示範如何執行繼承AsymmetricAlgorithm自類別的自訂非對稱演算法。The following code example demonstrates how to implement a custom asymmetric algorithm inherited from the AsymmetricAlgorithm class. 提供了額外的類別,以示範如何使用自訂類別。An additional class is provided to demonstrate how to use the custom class.

#using <System.Xml.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Text;
using namespace System::Security::Cryptography;
using namespace System::Reflection;

[assembly: AssemblyKeyFile("CustomCrypto.snk")];
[assembly: AssemblyVersion("1.0.0.0")];
[assembly: CLSCompliant(true)];
namespace Contoso
{
    // Define a CustomCrypto class that inherits from the AsymmetricAlgorithm
    // class.
    public ref class CustomCrypto :
        public System::Security::Cryptography::AsymmetricAlgorithm
        {
            // Declare local member variables.
        private:
            CspParameters^ cryptoServiceParameters;
            array<KeySizes^>^ customValidKeySizes;

            // Initialize a CustomCrypto with the default key size of 8.
        public:
            CustomCrypto()
            {
                customValidKeySizes = 
                    gcnew array<KeySizes^>{gcnew KeySizes(8, 64, 8)};
                this->KeySize = 8;
            }

            // Initialize a CustomCrypto with the specified key size.
        public:
            CustomCrypto(int keySize)
            {
                customValidKeySizes = 
                    gcnew array<KeySizes^>{gcnew KeySizes(8, 64, 8)};
                this->KeySize = keySize;
            }

            // Accessor function for keySizes member variable.
        public:
            property array<KeySizes^>^ LegalKeySizes
            {
                virtual array<KeySizes^>^ get() override
                {
                    return (array<KeySizes^>^)customValidKeySizes->Clone();
                }
            }

            // Modify the KeySizeValue property inherited from the Asymmetric
            // class. Prior to setting the value, ensure it falls within the
            // range identified in the local keySizes member variable.
        public:
            property int KeySize
            {
                virtual int get() override
                {
                    return KeySizeValue;
                }

                virtual void set(int value) override
                {
                    for (int i = 0; i < customValidKeySizes->Length; i++)
                    {
                        if (customValidKeySizes[i]->SkipSize == 0)
                        {
                            if (customValidKeySizes[i]->MinSize == value)
                            {
                                KeySizeValue = value;
                                return;
                            }
                        }
                        else
                        {
                            for (int j = customValidKeySizes[i]->MinSize;
                                j <= customValidKeySizes[i]->MaxSize;
                                j += customValidKeySizes[i]->SkipSize)
                            {
                                if (j == value)
                                {
                                    KeySizeValue = value;
                                    return;
                                }
                            }
                        }
                    }

                    // If the key does not fall within the range identified
                    // in the keySizes member variable, throw an exception.
                    throw gcnew CryptographicException("Invalid key size.");
                }
            }

            // Initialize the parameters with default values.
        public:
            void InitializeParameters()
            {
                cryptoServiceParameters = gcnew CspParameters();
                cryptoServiceParameters->ProviderName = "Contoso";
                cryptoServiceParameters->KeyContainerName = "SecurityBin1";
                cryptoServiceParameters->KeyNumber = 1;
                cryptoServiceParameters->ProviderType = 2;
            }

            // Parse specified xmlString for values to populate the CspParams
            // Expected XML schema:
            //      <ProviderName></ProviderName>
            //      <KeyContainerName></KeyContainerName>
            //      <KeyNumber></KeyNumber>
            //      <ProviderType></ProviderType>
        public:
            virtual void FromXmlString(String^ xmlString) override 
            {
                if (xmlString != nullptr)
                {
                    XmlDocument^ document = gcnew XmlDocument();
                    document->LoadXml(xmlString);
                    XmlNode^ firstNode = document->FirstChild;
                    XmlNodeList^ nodeList;

                    // Assemble parameters from values in each XML element.
                    cryptoServiceParameters = gcnew CspParameters();

                    // KeyContainerName is optional.
                    nodeList = 
                        document->GetElementsByTagName("KeyContainerName");
                    if (nodeList->Count > 0)
                    {
                        cryptoServiceParameters->KeyContainerName =
                            nodeList->Item(0)->InnerText;
                    }

                    // KeyNumber is optional.
                    nodeList = document->GetElementsByTagName("KeyNumber");
                    if (nodeList->Count > 0)
                    {
                        cryptoServiceParameters->KeyNumber =
                            Int32::Parse(nodeList->Item(0)->InnerText);
                    }

                    // ProviderName is optional.
                    nodeList = document->GetElementsByTagName("ProviderName");
                    if (nodeList->Count > 0)
                    {
                        cryptoServiceParameters->ProviderName =
                            nodeList->Item(0)->InnerText;
                    }

                    // ProviderType is optional.
                    nodeList = document->GetElementsByTagName("ProviderType");
                    if (nodeList->Count > 0)
                    {
                        cryptoServiceParameters->ProviderType =
                            Int32::Parse(nodeList->Item(0)->InnerText);
                    }
                }
                else
                {
                    throw gcnew ArgumentNullException("xmlString");
                }
            }

            // Create an XML string representation of the parameters in the
            // current customCrypto object.
        public:
            virtual String^ ToXmlString(bool includePrivateParameters) override
            {
                String^ keyContainerName = "";
                String^ keyNumber = "";
                String^ providerName = "";
                String^ providerType = "";

                if (cryptoServiceParameters != nullptr)
                {
                    keyContainerName = 
                        cryptoServiceParameters->KeyContainerName;
                    keyNumber = cryptoServiceParameters->KeyNumber.ToString();
                    providerName = cryptoServiceParameters->ProviderName;
                    providerType = 
                        cryptoServiceParameters->ProviderType.ToString();
                }

                StringBuilder^ sb = gcnew StringBuilder();
                sb->Append("<CustomCryptoKeyValue>");

                sb->Append("<KeyContainerName>");
                sb->Append(keyContainerName);
                sb->Append("</KeyContainerName>");

                sb->Append("<KeyNumber>");
                sb->Append(keyNumber);
                sb->Append("</KeyNumber>");

                sb->Append("<ProviderName>");
                sb->Append(providerName);
                sb->Append("</ProviderName>");

                sb->Append("<ProviderType>");
                sb->Append(providerType);
                sb->Append("</ProviderType>");

                sb->Append("</CustomCryptoKeyValue>");
                return(sb->ToString());
            }

            // Return the name for the key exchange algorithm.
        public:
            property String^ KeyExchangeAlgorithm 
            {
                virtual String^ get() override
                {
                    return "RSA-PKCS1-KeyEx";
                }
            }

            // Retrieves the name of the signature alogrithm.
        public:
            property String^ SignatureAlgorithm
            {
                virtual String^ get() override
                {
                    return "http://www.w3.org/2000/09/xmldsig#rsa-sha1";
                }
            }

            // Required member for implementing the AsymmetricAlgorithm class.
        protected:
            virtual ~CustomCrypto()
            {
            }

            // Call the Create method using the CustomCrypto assembly name.
            // The create function attempts to create a CustomCrypto 
            // object using the assembly name. This functionality requires 
            // modification of the machine.config file. Add the following 
            // section to the configuration element and modify the values 
            // of the cryptoClass to reflect what isinstalled 
            // in your machines GAC.
            //        <cryptoClass CustomCrypto="Contoso.CustomCrypto,
            //          CustomCrypto,
            //          Culture=neutral,
            //          PublicKeyToken=fdb9f9c4851028bf,
            //          Version=1.0.1448.27640" />
            //      <nameEntry name="Contoso.CustomCrypto" 
            //         class="CustomCrypto" />
            //      <nameEntry name="CustomCrypto" class="CustomCrypto" />

        public:
            static CustomCrypto^ Create() 
            {
                return Create("CustomCrypto");
            }

            // Create a CustomCrypto object by calling CrytoConfig's
            // CreateFromName method and casting the type to CustomCrypto.
            // The create function attempts to create a CustomCrypto object 
            // using the assembly name. This functionality requires 
            // modification of the machine.config file. Add the following 
            // section to the configuration element and modify the values 
            // of the cryptoClass to reflect what is installed 
            // in your machines GAC.
            //       <cryptoClass CustomCrypto="Contoso.CustomCrypto,
            //         CustomCrypto,
            //         Culture=neutral,
            //         PublicKeyToken=fdb9f9c4851028bf,
            //         Version=1.0.1448.27640" />
            //     <nameEntry name="Contoso.CustomCrypto" 
            //        class="CustomCrypto" />
            //     <nameEntry name="CustomCrypto" class="CustomCrypto" />

        public:
            static CustomCrypto^ Create(String^ algorithmName) 
            {
                return (CustomCrypto^) 
                    CryptoConfig::CreateFromName(algorithmName);
            }
        };
}
using System;
using System.Xml;
using System.Text;
using System.Security.Cryptography;
using System.Reflection;

[assembly: AssemblyKeyFile("CustomCrypto.snk")]
[assembly: AssemblyVersion("1.0.0.0")]
[assembly: CLSCompliant(true)]
namespace Contoso
{
    // Define a CustomCrypto class that inherits from the AsymmetricAlgorithm
    // class.
    public class CustomCrypto : 
        System.Security.Cryptography.AsymmetricAlgorithm
    {
        // Declare local member variables.
        private CspParameters cspParameters;
        private readonly KeySizes[] keySizes = {new KeySizes(8, 64, 8)};

        // Initialize a CustomCrypto with the default key size of 8.
        public CustomCrypto()
        {
            this.KeySize = 8;
        }

        // Initialize a CustomCrypto with the specified key size.
        public CustomCrypto(int keySize)
        {
            this.KeySize = keySize;
        }

        // Accessor function for keySizes member variable.
        public override KeySizes[] LegalKeySizes 
        { 
            get { return (KeySizes[])keySizes.Clone(); }
        }

        // Modify the KeySizeValue property inherited from the Asymmetric
        // class. Prior to setting the value, ensure it falls within the
        // range identified in the local keySizes member variable.
        public override int KeySize 
        {
            get { return KeySizeValue; }
            set
            {
                for (int i=0; i < keySizes.Length; i++)
                {
                    if (keySizes[i].SkipSize == 0) 
                    {
                        if (keySizes[i].MinSize == value)
                        {
                            KeySizeValue = value;
                            return;
                        }
                    }
                    else
                    {
                        for (int j = keySizes[i].MinSize;
                            j <= keySizes[i].MaxSize;
                            j += keySizes[i].SkipSize)
                        {
                            if (j == value)
                            {
                                KeySizeValue = value;
                                return;
                            }
                        }
                    }
                }

                // If the key does not fall within the range identified 
                // in the keySizes member variable, throw an exception.
                throw new CryptographicException("Invalid key size.");
            }
        }

        // Initialize the parameters with default values.
        public void InitializeParameters()
        {
            cspParameters = new CspParameters();
            cspParameters.ProviderName = "Contoso";
            cspParameters.KeyContainerName = "SecurityBin1";
            cspParameters.KeyNumber = 1;
            cspParameters.ProviderType = 2;
        }

        // Parse specified xmlString for values to populate the CspParams
        // Expected XML schema:
        //      <ProviderName></ProviderName>
        //      <KeyContainerName></KeyContainerName>
        //      <KeyNumber></KeyNumber>
        //      <ProviderType></ProviderType>
        public override void FromXmlString(string xmlString)
        {
            if (xmlString != null)
            {
                XmlDocument doc = new XmlDocument();
                doc.LoadXml(xmlString);
                XmlNode firstNode = doc.FirstChild;
                XmlNodeList nodeList;

                // Assemble parameters from values in each XML element.
                cspParameters = new CspParameters();

                // KeyContainerName is optional.
                nodeList = doc.GetElementsByTagName("KeyContainerName");
                string keyName = nodeList.Item(0).InnerText;
                if (keyName != null) 
                {
                    cspParameters.KeyContainerName = keyName;
                }

                // KeyNumber is optional.
                nodeList = doc.GetElementsByTagName("KeyNumber");
                string keyNumber = nodeList.Item(0).InnerText;
                if (keyNumber != null) 
                {
                    cspParameters.KeyNumber = Int32.Parse(keyNumber);
                }

                // ProviderName is optional.
                nodeList = doc.GetElementsByTagName("ProviderName");
                string providerName = nodeList.Item(0).InnerText;
                if (providerName != null) 
                {
                    cspParameters.ProviderName = providerName;
                }

                // ProviderType is optional.
                nodeList = doc.GetElementsByTagName("ProviderType");
                string providerType = nodeList.Item(0).InnerText;
                if (providerType != null) 
                {
                    cspParameters.ProviderType = Int32.Parse(providerType);
                }
            }
            else
            {
                throw new ArgumentNullException("xmlString");
            }
        }

        // Create an XML string representation of the parameters in the
        // current customCrypto object.
        public override string ToXmlString(bool includePrivateParameters)
        {
            string keyContainerName = "";
            string keyNumber = "";
            string providerName = "";
            string providerType = "";

            if (cspParameters != null)
            {
                keyContainerName = cspParameters.KeyContainerName;
                keyNumber = cspParameters.KeyNumber.ToString();
                providerName = cspParameters.ProviderName;
                providerType = cspParameters.ProviderType.ToString();
            }

            StringBuilder sb = new StringBuilder();
            sb.Append("<CustomCryptoKeyValue>");

            sb.Append("<KeyContainerName>");
            sb.Append(keyContainerName);
            sb.Append("</KeyContainerName>");

            sb.Append("<KeyNumber>");
            sb.Append(keyNumber);
            sb.Append("</KeyNumber>");

            sb.Append("<ProviderName>");
            sb.Append(providerName);
            sb.Append("</ProviderName>");

            sb.Append("<ProviderType>");
            sb.Append(providerType);
            sb.Append("</ProviderType>");

            sb.Append("</CustomCryptoKeyValue>");
            return(sb.ToString());
        }

        // Return the name for the key exchange algorithm.
        public override string KeyExchangeAlgorithm
        {
            get {return "RSA-PKCS1-KeyEx";}
        }

        // Retrieves the name of the signature alogrithm.
        public override string SignatureAlgorithm 
        {
            get {return "http://www.w3.org/2000/09/xmldsig#rsa-sha1";}
        }

        // Required member for implementing the AsymmetricAlgorithm class.
        protected override void Dispose(bool disposing) {}

        // Call the Create method using the CustomCrypto assembly name.
        // The create function attempts to create a CustomCrypto object using
        // the assembly name. This functionality requires modification of the
        // machine.config file. Add the following section to the configuration
        // element and modify the values of the cryptoClass to reflect what is
        // installed in your machines GAC.
        //        <cryptoClass CustomCrypto="Contoso.CustomCrypto, 
        //          CustomCrypto, 
        //          Culture=neutral, 
        //          PublicKeyToken=fdb9f9c4851028bf, 
        //          Version=1.0.1448.27640" />
        //      <nameEntry name="Contoso.CustomCrypto" class="CustomCrypto" />
        //      <nameEntry name="CustomCrypto" class="CustomCrypto" />
        new static public CustomCrypto Create() 
        {
            return Create("CustomCrypto");
        }

        // Create a CustomCrypto object by calling CrytoConfig's
        // CreateFromName method and casting the type to CustomCrypto.
        // The create function attempts to create a CustomCrypto object using
        // the assembly name. This functionality requires modification of the
        // machine.config file. Add the following section to the configuration
        // element and modify the values of the cryptoClass to reflect what is
        // installed in your machines GAC.
        //       <cryptoClass CustomCrypto="Contoso.CustomCrypto, 
        //         CustomCrypto, 
        //         Culture=neutral, 
        //         PublicKeyToken=fdb9f9c4851028bf, 
        //         Version=1.0.1448.27640" />
        //     <nameEntry name="Contoso.CustomCrypto" class="CustomCrypto" />
        //     <nameEntry name="CustomCrypto" class="CustomCrypto" />
        new static public CustomCrypto Create(String algorithmName) 
        {
            return (CustomCrypto) CryptoConfig.CreateFromName(algorithmName);
        }
    }
    class CustomCryptoImpl
    {
        [STAThread]
        static void Main(string[] args)
        {
            // Construct a CustomCrypto object and initialize its
            // CspParameters.
            CustomCrypto customCrypto = new CustomCrypto();
            customCrypto.InitializeParameters();

            // Display properties of the current customCrypto object.
            Console.WriteLine("*** CustomCrypto created with default " + 
                "parameters:");
            DisplayProperties(customCrypto);

            // Release all the resources used by this instance of 
            // CustomCrytpo.
            customCrypto.Clear();

            customCrypto = new CustomCrypto(64);
            // Create new parameters and set them by using the FromXmlString
            // method.
            string parameterXml = "<CustomCryptoKeyValue>";
            parameterXml += "<ProviderName>Contoso</ProviderName>";
            parameterXml += "<KeyContainerName>SecurityBin2";
            parameterXml += "</KeyContainerName>";
            parameterXml += "<KeyNumber>1</KeyNumber>";
            parameterXml += "<ProviderType>2</ProviderType>";
            parameterXml += "</CustomCryptoKeyValue>";
            customCrypto.FromXmlString(parameterXml);

            // Display the properties of a customCrypto object created with
            // custom parameters.
            Console.WriteLine("\n*** " + 
                "CustomCrypto created with custom parameters:");
            DisplayProperties(customCrypto);

            // Create an object by using the assembly name.
            try
            {
                CustomCrypto myCryptoA = CustomCrypto.Create("CustomCrypto");
                if (myCryptoA != null)
                {
                    Console.Write("\n*** " + 
                        "Successfully created CustomCrytpo from");
                    Console.WriteLine(" the Create method.");

                    DisplayProperties(myCryptoA);
                }
                else
                {
                    Console.Write("Unable to create CustomCrytpo from ");
                    Console.WriteLine(" the Create method.");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
            
            Console.WriteLine("This sample completed successfully; " +
                "press Enter to exit.");
            Console.ReadLine();
        }
        // Display the properties of the specified CustomCrypto object to the
        // console.
        public static void DisplayProperties(CustomCrypto customCrypto)
        {
            try
            {
                // Retrieve the class description for the customCrypto object.
                string classDescription = customCrypto.ToString();

                Console.WriteLine(classDescription);
                Console.Write("KeyExchangeAlgorithm: ");
                Console.WriteLine(customCrypto.KeyExchangeAlgorithm);
                Console.Write("SignatureAlgorithm: ");
                Console.WriteLine(customCrypto.SignatureAlgorithm);
                Console.WriteLine("KeySize: " + customCrypto.KeySize);
                Console.WriteLine("Parameters described in Xml format:");
                Console.WriteLine(customCrypto.ToXmlString(true));

                // Display the MinSize, MaxSize, and SkipSize properties of 
                // each KeySize item in the local keySizes member variable.
                KeySizes[] legalKeySizes = customCrypto.LegalKeySizes;
                if (legalKeySizes.Length > 0)
                {
                    for (int i=0; i < legalKeySizes.Length; i++)
                    {
                        Console.Write("Keysize" + i + " min, max, step: ");
                        Console.Write(legalKeySizes[i].MinSize + ", ");
                        Console.Write(legalKeySizes[i].MaxSize + ", ");
                        Console.WriteLine(legalKeySizes[i].SkipSize + ", ");
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Caught unexpected exception: " + 
                    ex.ToString());
            }
        }
    }
}
//
// This sample produces the following output:
//
// *** CustomCrypto created with default parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 8
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin1</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8, 
// 
// *** CustomCrypto created with custom parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 64
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin2</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8, 
// Unable to create CustomCrytpo from  the Create method
// This sample completed successfully; press Exit to continue.
Imports System.Xml
Imports System.Text
Imports System.Security.Cryptography
Imports System.Reflection

<Assembly: AssemblyKeyFile("CustomCrypto.snk")> 
<Assembly: AssemblyVersion("1.0.0.0")> 
<Assembly: CLSCompliant(True)> 
Namespace Contoso
    ' Define a vbCustomCrypto class that inherits from the AsymmetricAlgorithm
    ' class.
    Class vbCustomCrypto
        Inherits System.Security.Cryptography.AsymmetricAlgorithm

        ' Declare local member variables.
        Private cspParameters As CspParameters
        Private ReadOnly keySizes() As keySizes = {New keySizes(8, 64, 8)}

        ' Initialize a vbCustomCrypto with the default key size of 8.
        Public Sub New()
            Me.KeySize = 8
        End Sub

        ' Initialize a vbCustomCrypto with the specified key size.
        Public Sub New(ByVal keySize As Integer)
            Me.KeySize = keySize
        End Sub

        ' Modify the KeySizeValue property inherited from the Asymmetric
        ' class. Prior to setting the value, ensure it falls within the
        ' range identified in the local keySizes member variable.
        Public Overrides Property KeySize() As Integer
            Get
                Return KeySizeValue
            End Get
            Set(ByVal Value As Integer)
                For i As Int16 = 0 To keySizes.Length - 1 Step i
                    If (keySizes(i).SkipSize.Equals(0)) Then
                        If (keySizes(i).MinSize.Equals(Value)) Then
                            KeySizeValue = Value
                            Return
                        End If
                    Else
                        For j As Integer = keySizes(i).MinSize _
                            To keySizes(i).MaxSize _
                            Step keySizes(i).SkipSize
                            If (j.Equals(Value)) Then
                                KeySizeValue = Value
                                Return
                            End If
                        Next
                    End If
                Next
                ' If the key does not fall within the range identified 
                ' in the keySizes member variable, throw an exception.
                Throw New CryptographicException("Invalid key size.")
            End Set
        End Property
        ' Accessor function for keySizes member variable.
        public Overrides Readonly Property LegalKeySizes as KeySizes()
            Get
                Return keySizes
            End Get
        End Property
        ' Initialize the parameters with default values.
        Public Sub InitializeParameters()
            cspParameters = New CspParameters
            cspParameters.ProviderName = "Contoso"
            cspParameters.KeyContainerName = "SecurityBin1"
            cspParameters.KeyNumber = 1
            cspParameters.ProviderType = 2
        End Sub

        ' Parse specified xmlString for values to populate the CspParams
        ' Expected XML schema:
        '      <ProviderName></ProviderName>
        '      <KeyContainerName></KeyContainerName>
        '      <KeyNumber></KeyNumber>
        '      <ProviderType></ProviderType>
        Public Overrides Sub FromXmlString(ByVal xmlString As String)
            If Not xmlString Is Nothing Then
                Dim doc As New XmlDocument
                doc.LoadXml(xmlString)
                Dim firstNode As XmlNode = doc.FirstChild
                Dim nodeList As XmlNodeList

                ' Assemble parameters from values in each XML element.
                cspParameters = New CspParameters

                ' KeyContainerName is optional.
                nodeList = doc.GetElementsByTagName("KeyContainerName")
                Dim keyName As String = nodeList.Item(0).InnerText
                If Not keyName Is Nothing Then
                    cspParameters.KeyContainerName = keyName
                End If

                ' KeyNumber is optional.
                nodeList = doc.GetElementsByTagName("KeyNumber")
                Dim keyNumber As String = nodeList.Item(0).InnerText
                If Not keyNumber Is Nothing Then
                    cspParameters.KeyNumber = Int32.Parse(keyNumber)
                End If

                ' ProviderName is optional.
                nodeList = doc.GetElementsByTagName("ProviderName")
                Dim providerName As String = nodeList.Item(0).InnerText
                If Not providerName Is Nothing Then
                    cspParameters.ProviderName = providerName
                End If

                ' ProviderType is optional.
                nodeList = doc.GetElementsByTagName("ProviderType")
                Dim providerType As String = nodeList.Item(0).InnerText
                If Not providerType Is Nothing Then
                    cspParameters.ProviderType = Int32.Parse(providerType)
                End If
            Else
                Throw New ArgumentNullException("xmlString")
            End If
        End Sub

        ' Create an XML string representation of the parameters in the current
        ' vbCustomCrypto object.
        Public Overrides Function ToXmlString( _
            ByVal includePrivateParameters As Boolean) As String

            Dim keyContainerName As String = ""
            Dim keyNumber As String = ""
            Dim providerName As String = ""
            Dim providerType As String = ""

            If Not cspParameters Is Nothing Then
                keyContainerName = cspParameters.KeyContainerName
                keyNumber = cspParameters.KeyNumber.ToString()
                providerName = cspParameters.ProviderName
                providerType = cspParameters.ProviderType.ToString()
            End If

            Dim xmlBuilder As New StringBuilder
            xmlBuilder.Append("<CustomCryptoKeyValue>")

            xmlBuilder.Append("<KeyContainerName>")
            xmlBuilder.Append(keyContainerName)
            xmlBuilder.Append("</KeyContainerName>")

            xmlBuilder.Append("<KeyNumber>")
            xmlBuilder.Append(keyNumber)
            xmlBuilder.Append("</KeyNumber>")

            xmlBuilder.Append("<ProviderName>")
            xmlBuilder.Append(providerName)
            xmlBuilder.Append("</ProviderName>")

            xmlBuilder.Append("<ProviderType>")
            xmlBuilder.Append(providerType)
            xmlBuilder.Append("</ProviderType>")

            xmlBuilder.Append("</CustomCryptoKeyValue>")
            Return (xmlBuilder.ToString())
        End Function

        ' Return the name for the key exchange algorithm.
        Public Overrides ReadOnly Property KeyExchangeAlgorithm() As String
            Get
                Return "RSA-PKCS1-KeyEx"
            End Get
        End Property

        ' Retrieves the name of the signature alogrithm.
        Public Overrides ReadOnly Property SignatureAlgorithm() As String
            Get
                Return "http://www.w3.org/2000/09/xmldsig#rsa-sha1"
            End Get
        End Property

        ' Required member for implementing the AsymmetricAlgorithm class.
        Protected Overrides Sub Dispose(ByVal disposing As Boolean)

        End Sub

        ' The create function attempts to create a vbCustomCrypto object using
        ' the assembly name. This functionality requires modification of the
        ' machine.config file. Add the following section to the configuration
        ' element and modify the values of the cryptoClass to reflect what is
        ' installed in your machines GAC.
        '          <cryptoClass vbCustomCrypto="Contoso.vbCustomCrypto, 
        '            vbCustomCrypto, 
        '            Culture=neutral, 
        '            PublicKeyToken=fdb9f9c4851028bf, 
        '            Version=1.0.1448.27640" />
        '        <nameEntry name="Contoso.vbCustomCrypto" 
        '                   class="vbCustomCrypto" />
        '        <nameEntry name="vbCustomCrypto" class="vbCustomCrypto" />
        Public Shadows Function Create() As vbCustomCrypto
            Return Create("vbCustomCrypto")
        End Function

        ' Create a CustomCrypto object by calling CrytoConfig's
        ' CreateFromName method and casting the type to CustomCrypto.
        ' The create function attempts to create a vbCustomCrypto object using
        ' the assembly name. This functionality requires modification of the
        ' machine.config file. Add the following section to the configuration
        ' element and modify the values of the cryptoClass to reflect what is
        ' installed in your machines GAC.
        '          <cryptoClass vbCustomCrypto="Contoso.vbCustomCrypto, 
        '            vbCustomCrypto, 
        '            Culture=neutral, 
        '            PublicKeyToken=fdb9f9c4851028bf, 
        '            Version=1.0.1448.27640" />
        '        <nameEntry name="Contoso.vbCustomCrypto" 
        '                   class="vbCustomCrypto" />
        '        <nameEntry name="vbCustomCrypto" class="vbCustomCrypto" />
        Public Shadows Function Create( _
            ByVal algorithmName As String) As vbCustomCrypto

            Return CType( _
                CryptoConfig.CreateFromName(algorithmName), _
                vbCustomCrypto)

        End Function
    End Class
    Class Form1
        Inherits System.Windows.Forms.Form

        ' Event handler for Run button.
        Private Sub Button1_Click( _
            ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles Button1.Click

            tbxOutput.Cursor = Cursors.WaitCursor
            tbxOutput.Text = ""

            ' Construct a CustomCrypto object and initialize its
            ' CspParameters.
            Dim customCrypto As New Contoso.vbCustomCrypto
            customCrypto.InitializeParameters()

            ' Display properties of the current vbCustomCrypto object.
            WriteLine("*** CustomCrypto created with default parameters:")
            DisplayProperties(customCrypto)

            ' Release all the resources used by this instance of CustomCrytpo.
            customCrypto.Clear()

            customCrypto = New Contoso.vbCustomCrypto(64)
            ' Create new parameters and set them by using the
            ' FromXmlString method.
            Dim parameterXml As String = "<CustomCryptoKeyValue>"
            parameterXml += "<ProviderName>Contoso</ProviderName>"
            parameterXml += "<KeyContainerName>SecurityBin2"
            parameterXml += "</KeyContainerName>"
            parameterXml += "<KeyNumber>1</KeyNumber>"
            parameterXml += "<ProviderType>2</ProviderType>"
            parameterXml += "</CustomCryptoKeyValue>"
            customCrypto.FromXmlString(parameterXml)

            ' Display the properties of a customCrypto object created with
            ' custom parameters.
            WriteLine(vbCrLf + "*** " + _
                "CustomCrypto created with custom parameters:")
            DisplayProperties(customCrypto)

            ' Create an object by using the assembly name.
            Try
                Dim createdCrypto As Contoso.vbCustomCrypto
                createdCrypto = customCrypto.Create("vbCustomCrypto")

                If (Not createdCrypto Is Nothing) Then
                    Write(vbCrLf + "*** Successfully created vbCustomCrytpo ")
                    WriteLine("from the Create method.")

                    DisplayProperties(createdCrypto)
                Else
                    Write("Unable to create CustomCrytpo from ")
                    WriteLine(" the Create method.")
                End If
            Catch ex As Exception
                WriteLine(ex.ToString())
            End Try

            ' Align interface and conclude application.
            WriteLine("This sample completed successfully;" + _
                " press Exit to continue.")

            ' Reset the cursor.
            tbxOutput.Cursor = Cursors.Default
        End Sub
        ' Display the properties of the specified CustomCrypto object to
        ' the output texbox.
        Public Sub DisplayProperties( _
            ByVal customCrypto As Contoso.vbCustomCrypto)

            Try
                ' Retrieve the class description for the customCrypto object.
                Dim classDescription As String = customCrypto.ToString()

                WriteLine(classDescription)
                WriteLine("KeyExchangeAlgorithm: " + _
                    customCrypto.KeyExchangeAlgorithm)
                WriteLine("SignatureAlgorithm: " + _
                    customCrypto.SignatureAlgorithm)
                WriteLine("KeySize: " + customCrypto.KeySize.ToString())
                WriteLine("Parameters described in Xml format:")
                WriteLine(customCrypto.ToXmlString(True))

                ' Display the MinSize, MaxSize, and SkipSize properties of 
                ' each KeySize item in the local keySizes member variable.
                Dim legalKeySizes() As KeySizes = customCrypto.LegalKeySizes
                If (legalKeySizes.Length > 0) Then
                    For i As Integer = 0 To legalKeySizes.Length - 1 Step 1
                        Write("Keysize" + i.ToString() + " min, max, step: ")
                        Write(legalKeySizes(i).MinSize.ToString() + ", ")
                        Write(legalKeySizes(i).MaxSize.ToString() + ", ")
                        Write(legalKeySizes(i).SkipSize.ToString() + ", ")
                        WriteLine("")
                    Next
                End If
            Catch ex As Exception
                WriteLine("Caught unexpected exception: " + ex.ToString())
            End Try
        End Sub
        ' Write the specified message and carriage return to the output
        ' textbox.
        Private Sub WriteLine(ByVal message As String)
            tbxOutput.AppendText(message + vbCrLf)
        End Sub
        ' Write the specified message to the output textbox.
        Private Sub Write(ByVal message As String)
            tbxOutput.AppendText(message)
        End Sub
        ' Event handler for Exit button.
        Private Sub Button2_Click( _
            ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles Button2.Click

            Application.Exit()
        End Sub


        Public Sub New()
            MyBase.New()

            'This call is required by the Windows Form Designer.
            InitializeComponent()

            'Add any initialization after the InitializeComponent() call

        End Sub

        'Form overrides dispose to clean up the component list.
        Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
            If disposing Then
                If Not (components Is Nothing) Then
                    components.Dispose()
                End If
            End If
            MyBase.Dispose(disposing)
        End Sub

        'Required by the Windows Form Designer
        Private components As System.ComponentModel.IContainer

        'NOTE: The following procedure is required by the Windows Form 
        'Designer. It can be modified using the Windows Form Designer. 
        'Do not modify it using the code editor.
        Friend WithEvents Panel2 As System.Windows.Forms.Panel
        Friend WithEvents Panel1 As System.Windows.Forms.Panel
        Friend WithEvents Button1 As System.Windows.Forms.Button
        Friend WithEvents Button2 As System.Windows.Forms.Button
        Friend WithEvents tbxOutput As System.Windows.Forms.RichTextBox
        <System.Diagnostics.DebuggerStepThrough()> _
        Private Sub InitializeComponent()
            Me.Panel2 = New System.Windows.Forms.Panel
            Me.Button1 = New System.Windows.Forms.Button
            Me.Button2 = New System.Windows.Forms.Button
            Me.Panel1 = New System.Windows.Forms.Panel
            Me.tbxOutput = New System.Windows.Forms.RichTextBox
            Me.Panel2.SuspendLayout()
            Me.Panel1.SuspendLayout()
            Me.SuspendLayout()
            '
            'Panel2
            '
            Me.Panel2.Controls.Add(Me.Button1)
            Me.Panel2.Controls.Add(Me.Button2)
            Me.Panel2.Dock = System.Windows.Forms.DockStyle.Bottom
            Me.Panel2.DockPadding.All = 20
            Me.Panel2.Location = New System.Drawing.Point(0, 320)
            Me.Panel2.Name = "Panel2"
            Me.Panel2.Size = New System.Drawing.Size(616, 64)
            Me.Panel2.TabIndex = 1
            '
            'Button1
            '
            Me.Button1.Dock = System.Windows.Forms.DockStyle.Right
            Me.Button1.Font = New System.Drawing.Font( _
                "Microsoft Sans Serif", _
                9.0!, _
                System.Drawing.FontStyle.Regular, _
                System.Drawing.GraphicsUnit.Point, _
                CType(0, Byte))
            Me.Button1.Location = New System.Drawing.Point(446, 20)
            Me.Button1.Name = "Button1"
            Me.Button1.Size = New System.Drawing.Size(75, 24)
            Me.Button1.TabIndex = 2
            Me.Button1.Text = "&Run"
            '
            'Button2
            '
            Me.Button2.Dock = System.Windows.Forms.DockStyle.Right
            Me.Button2.Font = New System.Drawing.Font( _
                "Microsoft Sans Serif", _
                9.0!, _
                System.Drawing.FontStyle.Regular, _
                System.Drawing.GraphicsUnit.Point, _
                CType(0, Byte))
            Me.Button2.Location = New System.Drawing.Point(521, 20)
            Me.Button2.Name = "Button2"
            Me.Button2.Size = New System.Drawing.Size(75, 24)
            Me.Button2.TabIndex = 3
            Me.Button2.Text = "E&xit"
            '
            'Panel1
            '
            Me.Panel1.Controls.Add(Me.tbxOutput)
            Me.Panel1.Dock = System.Windows.Forms.DockStyle.Fill
            Me.Panel1.DockPadding.All = 20
            Me.Panel1.Location = New System.Drawing.Point(0, 0)
            Me.Panel1.Name = "Panel1"
            Me.Panel1.Size = New System.Drawing.Size(616, 320)
            Me.Panel1.TabIndex = 2
            '
            'tbxOutput
            '
            Me.tbxOutput.AccessibleDescription = _
                "Displays output from application."
            Me.tbxOutput.AccessibleName = "Output textbox."
            Me.tbxOutput.Dock = System.Windows.Forms.DockStyle.Fill
            Me.tbxOutput.Location = New System.Drawing.Point(20, 20)
            Me.tbxOutput.Name = "tbxOutput"
            Me.tbxOutput.Size = New System.Drawing.Size(576, 280)
            Me.tbxOutput.TabIndex = 1
            Me.tbxOutput.Text = "Click the Run button to run the application."
            '
            'Form1
            '
            Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15)
            Me.ClientSize = New System.Drawing.Size(616, 384)
            Me.Controls.Add(Me.Panel1)
            Me.Controls.Add(Me.Panel2)
            Me.Name = "Form1"
            Me.Text = "AsymmetricAlgorithm"
            Me.Panel2.ResumeLayout(False)
            Me.Panel1.ResumeLayout(False)
            Me.ResumeLayout(False)

        End Sub

    End Class
End Namespace
'
' This sample produces the following output:
'
' *** CustomCrypto created with default parameters:
' Contoso.vbCustomCrypto
' KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
' SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
' KeySize: 8
' Parameters described in Xml format:
' <CustomCryptoKeyValue><KeyContainerName>SecurityBin1</KeyContainerName>
' <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
' <ProviderType>2</ProviderType></CustomCryptoKeyValue>
' Keysize0 min, max, step: 8, 64, 8, 
' 
' *** CustomCrypto created with custom parameters:
' Contoso.vbCustomCrypto
' KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
' SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
' KeySize: 64
' Parameters described in Xml format:
' <CustomCryptoKeyValue><KeyContainerName>SecurityBin2</KeyContainerName>
' <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
' <ProviderType>2</ProviderType></CustomCryptoKeyValue>
' Keysize0 min, max, step: 8, 64, 8, 
' Unable to create CustomCrytpo from  the Create method
' This sample completed successfully; press Enter to exit.

以下是另一個示範如何使用自訂類別的類別。Here's an additional class that demonstrates how to use the custom class.

#using <System.Xml.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Xml;
using namespace System::Text;
using namespace System::Security::Cryptography;

// Display the properties of the specified CustomCrypto object to the
// console.
static void DisplayProperties(Contoso::CustomCrypto^ customCryptoAlgorithm)
{
    // Retrieve the class description for the customCrypto object.
    String^ classDescription = customCryptoAlgorithm->ToString();

    Console::WriteLine(classDescription);
    Console::WriteLine("KeyExchangeAlgorithm: {0}",
        customCryptoAlgorithm->KeyExchangeAlgorithm);
    Console::WriteLine("SignatureAlgorithm: {0}",
        customCryptoAlgorithm->SignatureAlgorithm);
    Console::WriteLine("KeySize: {0}",
        customCryptoAlgorithm->KeySize);
    Console::WriteLine("Parameters described in Xml format:");
    Console::WriteLine(customCryptoAlgorithm->ToXmlString(true));

    // Display the MinSize, MaxSize, and SkipSize properties of
    // each KeySize item in the local keySizes member variable.
    array<KeySizes^>^ legalKeySizes = customCryptoAlgorithm->LegalKeySizes;
    for (int i = 0; i < legalKeySizes->Length; i++)
    {
        Console::WriteLine(
            "Keysize{0} min, max, step: {1}, {2}, {3}, ", i,
            legalKeySizes[i]->MinSize,
            legalKeySizes[i]->MaxSize,
            legalKeySizes[i]->SkipSize);
    }
}

[STAThread]
int main()
{
    // Construct a CustomCrypto object and initialize its
    // CspParameters.
    Contoso::CustomCrypto^ customCryptoAlgorithm = gcnew Contoso::CustomCrypto();
    customCryptoAlgorithm->InitializeParameters();

    // Display properties of the current customCrypto object.
    Console::WriteLine(
        "*** CustomCrypto created with default parameters:");
    DisplayProperties(customCryptoAlgorithm);

    // Release all the resources used by this instance of
    // CustomCrypto.
    customCryptoAlgorithm->Clear();

    customCryptoAlgorithm = gcnew Contoso::CustomCrypto(64);
    // Create new parameters and set them by using the FromXmlString
    // method.
    String^ parameterXml = "<CustomCryptoKeyValue>" +
        "<ProviderName>Contoso</ProviderName>" +
        "<KeyContainerName>SecurityBin2</KeyContainerName>" +
        "<KeyNumber>1</KeyNumber>" +
        "<ProviderType>2</ProviderType>" +
        "</CustomCryptoKeyValue>";
    customCryptoAlgorithm->FromXmlString(parameterXml);

    // Display the properties of a customCrypto object created with
    // custom parameters.
    Console::WriteLine(
        "{0}*** CustomCrypto created with custom parameters:", Environment::NewLine);
    DisplayProperties(customCryptoAlgorithm);

    // Create an object by using the assembly name.
    Contoso::CustomCrypto^ cryptoFromAssembly =
        Contoso::CustomCrypto::Create("CustomCrypto");
    if (cryptoFromAssembly != nullptr)
    {
        Console::WriteLine("{0}*** Successfully created " +
            "CustomCrypto from the Create method.", Environment::NewLine);
        DisplayProperties(cryptoFromAssembly);
    }
    else
    {
        Console::WriteLine("Unable to create CustomCrypto from " +
            "the Create method.");
    }

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

//
// This sample produces the following output:
//
// *** CustomCrypto created with default parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 8
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin1</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8,
//
// *** CustomCrypto created with custom parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 64
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin2</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8,
// Unable to create CustomCrypto from the Create method
// This sample completed successfully; press Enter to exit.
    class CustomCryptoImpl
    {
        [STAThread]
        static void Main(string[] args)
        {
            // Construct a CustomCrypto object and initialize its
            // CspParameters.
            CustomCrypto customCrypto = new CustomCrypto();
            customCrypto.InitializeParameters();

            // Display properties of the current customCrypto object.
            Console.WriteLine("*** CustomCrypto created with default " + 
                "parameters:");
            DisplayProperties(customCrypto);

            // Release all the resources used by this instance of 
            // CustomCrytpo.
            customCrypto.Clear();

            customCrypto = new CustomCrypto(64);
            // Create new parameters and set them by using the FromXmlString
            // method.
            string parameterXml = "<CustomCryptoKeyValue>";
            parameterXml += "<ProviderName>Contoso</ProviderName>";
            parameterXml += "<KeyContainerName>SecurityBin2";
            parameterXml += "</KeyContainerName>";
            parameterXml += "<KeyNumber>1</KeyNumber>";
            parameterXml += "<ProviderType>2</ProviderType>";
            parameterXml += "</CustomCryptoKeyValue>";
            customCrypto.FromXmlString(parameterXml);

            // Display the properties of a customCrypto object created with
            // custom parameters.
            Console.WriteLine("\n*** " + 
                "CustomCrypto created with custom parameters:");
            DisplayProperties(customCrypto);

            // Create an object by using the assembly name.
            try
            {
                CustomCrypto myCryptoA = CustomCrypto.Create("CustomCrypto");
                if (myCryptoA != null)
                {
                    Console.Write("\n*** " + 
                        "Successfully created CustomCrytpo from");
                    Console.WriteLine(" the Create method.");

                    DisplayProperties(myCryptoA);
                }
                else
                {
                    Console.Write("Unable to create CustomCrytpo from ");
                    Console.WriteLine(" the Create method.");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
            
            Console.WriteLine("This sample completed successfully; " +
                "press Enter to exit.");
            Console.ReadLine();
        }
        // Display the properties of the specified CustomCrypto object to the
        // console.
        public static void DisplayProperties(CustomCrypto customCrypto)
        {
            try
            {
                // Retrieve the class description for the customCrypto object.
                string classDescription = customCrypto.ToString();

                Console.WriteLine(classDescription);
                Console.Write("KeyExchangeAlgorithm: ");
                Console.WriteLine(customCrypto.KeyExchangeAlgorithm);
                Console.Write("SignatureAlgorithm: ");
                Console.WriteLine(customCrypto.SignatureAlgorithm);
                Console.WriteLine("KeySize: " + customCrypto.KeySize);
                Console.WriteLine("Parameters described in Xml format:");
                Console.WriteLine(customCrypto.ToXmlString(true));

                // Display the MinSize, MaxSize, and SkipSize properties of 
                // each KeySize item in the local keySizes member variable.
                KeySizes[] legalKeySizes = customCrypto.LegalKeySizes;
                if (legalKeySizes.Length > 0)
                {
                    for (int i=0; i < legalKeySizes.Length; i++)
                    {
                        Console.Write("Keysize" + i + " min, max, step: ");
                        Console.Write(legalKeySizes[i].MinSize + ", ");
                        Console.Write(legalKeySizes[i].MaxSize + ", ");
                        Console.WriteLine(legalKeySizes[i].SkipSize + ", ");
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Caught unexpected exception: " + 
                    ex.ToString());
            }
        }
    }
}
//
// This sample produces the following output:
//
// *** CustomCrypto created with default parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 8
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin1</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8, 
// 
// *** CustomCrypto created with custom parameters:
// Contoso.vbCustomCrypto
// KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
// SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
// KeySize: 64
// Parameters described in Xml format:
// <CustomCryptoKeyValue><KeyContainerName>SecurityBin2</KeyContainerName>
// <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
// <ProviderType>2</ProviderType></CustomCryptoKeyValue>
// Keysize0 min, max, step: 8, 64, 8, 
// Unable to create CustomCrytpo from  the Create method
// This sample completed successfully; press Exit to continue.
    Class Form1
        Inherits System.Windows.Forms.Form

        ' Event handler for Run button.
        Private Sub Button1_Click( _
            ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles Button1.Click

            tbxOutput.Cursor = Cursors.WaitCursor
            tbxOutput.Text = ""

            ' Construct a CustomCrypto object and initialize its
            ' CspParameters.
            Dim customCrypto As New Contoso.vbCustomCrypto
            customCrypto.InitializeParameters()

            ' Display properties of the current vbCustomCrypto object.
            WriteLine("*** CustomCrypto created with default parameters:")
            DisplayProperties(customCrypto)

            ' Release all the resources used by this instance of CustomCrytpo.
            customCrypto.Clear()

            customCrypto = New Contoso.vbCustomCrypto(64)
            ' Create new parameters and set them by using the
            ' FromXmlString method.
            Dim parameterXml As String = "<CustomCryptoKeyValue>"
            parameterXml += "<ProviderName>Contoso</ProviderName>"
            parameterXml += "<KeyContainerName>SecurityBin2"
            parameterXml += "</KeyContainerName>"
            parameterXml += "<KeyNumber>1</KeyNumber>"
            parameterXml += "<ProviderType>2</ProviderType>"
            parameterXml += "</CustomCryptoKeyValue>"
            customCrypto.FromXmlString(parameterXml)

            ' Display the properties of a customCrypto object created with
            ' custom parameters.
            WriteLine(vbCrLf + "*** " + _
                "CustomCrypto created with custom parameters:")
            DisplayProperties(customCrypto)

            ' Create an object by using the assembly name.
            Try
                Dim createdCrypto As Contoso.vbCustomCrypto
                createdCrypto = customCrypto.Create("vbCustomCrypto")

                If (Not createdCrypto Is Nothing) Then
                    Write(vbCrLf + "*** Successfully created vbCustomCrytpo ")
                    WriteLine("from the Create method.")

                    DisplayProperties(createdCrypto)
                Else
                    Write("Unable to create CustomCrytpo from ")
                    WriteLine(" the Create method.")
                End If
            Catch ex As Exception
                WriteLine(ex.ToString())
            End Try

            ' Align interface and conclude application.
            WriteLine("This sample completed successfully;" + _
                " press Exit to continue.")

            ' Reset the cursor.
            tbxOutput.Cursor = Cursors.Default
        End Sub
        ' Display the properties of the specified CustomCrypto object to
        ' the output texbox.
        Public Sub DisplayProperties( _
            ByVal customCrypto As Contoso.vbCustomCrypto)

            Try
                ' Retrieve the class description for the customCrypto object.
                Dim classDescription As String = customCrypto.ToString()

                WriteLine(classDescription)
                WriteLine("KeyExchangeAlgorithm: " + _
                    customCrypto.KeyExchangeAlgorithm)
                WriteLine("SignatureAlgorithm: " + _
                    customCrypto.SignatureAlgorithm)
                WriteLine("KeySize: " + customCrypto.KeySize.ToString())
                WriteLine("Parameters described in Xml format:")
                WriteLine(customCrypto.ToXmlString(True))

                ' Display the MinSize, MaxSize, and SkipSize properties of 
                ' each KeySize item in the local keySizes member variable.
                Dim legalKeySizes() As KeySizes = customCrypto.LegalKeySizes
                If (legalKeySizes.Length > 0) Then
                    For i As Integer = 0 To legalKeySizes.Length - 1 Step 1
                        Write("Keysize" + i.ToString() + " min, max, step: ")
                        Write(legalKeySizes(i).MinSize.ToString() + ", ")
                        Write(legalKeySizes(i).MaxSize.ToString() + ", ")
                        Write(legalKeySizes(i).SkipSize.ToString() + ", ")
                        WriteLine("")
                    Next
                End If
            Catch ex As Exception
                WriteLine("Caught unexpected exception: " + ex.ToString())
            End Try
        End Sub
        ' Write the specified message and carriage return to the output
        ' textbox.
        Private Sub WriteLine(ByVal message As String)
            tbxOutput.AppendText(message + vbCrLf)
        End Sub
        ' Write the specified message to the output textbox.
        Private Sub Write(ByVal message As String)
            tbxOutput.AppendText(message)
        End Sub
        ' Event handler for Exit button.
        Private Sub Button2_Click( _
            ByVal sender As System.Object, _
            ByVal e As System.EventArgs) Handles Button2.Click

            Application.Exit()
        End Sub


        Public Sub New()
            MyBase.New()

            'This call is required by the Windows Form Designer.
            InitializeComponent()

            'Add any initialization after the InitializeComponent() call

        End Sub

        'Form overrides dispose to clean up the component list.
        Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
            If disposing Then
                If Not (components Is Nothing) Then
                    components.Dispose()
                End If
            End If
            MyBase.Dispose(disposing)
        End Sub

        'Required by the Windows Form Designer
        Private components As System.ComponentModel.IContainer

        'NOTE: The following procedure is required by the Windows Form 
        'Designer. It can be modified using the Windows Form Designer. 
        'Do not modify it using the code editor.
        Friend WithEvents Panel2 As System.Windows.Forms.Panel
        Friend WithEvents Panel1 As System.Windows.Forms.Panel
        Friend WithEvents Button1 As System.Windows.Forms.Button
        Friend WithEvents Button2 As System.Windows.Forms.Button
        Friend WithEvents tbxOutput As System.Windows.Forms.RichTextBox
        <System.Diagnostics.DebuggerStepThrough()> _
        Private Sub InitializeComponent()
            Me.Panel2 = New System.Windows.Forms.Panel
            Me.Button1 = New System.Windows.Forms.Button
            Me.Button2 = New System.Windows.Forms.Button
            Me.Panel1 = New System.Windows.Forms.Panel
            Me.tbxOutput = New System.Windows.Forms.RichTextBox
            Me.Panel2.SuspendLayout()
            Me.Panel1.SuspendLayout()
            Me.SuspendLayout()
            '
            'Panel2
            '
            Me.Panel2.Controls.Add(Me.Button1)
            Me.Panel2.Controls.Add(Me.Button2)
            Me.Panel2.Dock = System.Windows.Forms.DockStyle.Bottom
            Me.Panel2.DockPadding.All = 20
            Me.Panel2.Location = New System.Drawing.Point(0, 320)
            Me.Panel2.Name = "Panel2"
            Me.Panel2.Size = New System.Drawing.Size(616, 64)
            Me.Panel2.TabIndex = 1
            '
            'Button1
            '
            Me.Button1.Dock = System.Windows.Forms.DockStyle.Right
            Me.Button1.Font = New System.Drawing.Font( _
                "Microsoft Sans Serif", _
                9.0!, _
                System.Drawing.FontStyle.Regular, _
                System.Drawing.GraphicsUnit.Point, _
                CType(0, Byte))
            Me.Button1.Location = New System.Drawing.Point(446, 20)
            Me.Button1.Name = "Button1"
            Me.Button1.Size = New System.Drawing.Size(75, 24)
            Me.Button1.TabIndex = 2
            Me.Button1.Text = "&Run"
            '
            'Button2
            '
            Me.Button2.Dock = System.Windows.Forms.DockStyle.Right
            Me.Button2.Font = New System.Drawing.Font( _
                "Microsoft Sans Serif", _
                9.0!, _
                System.Drawing.FontStyle.Regular, _
                System.Drawing.GraphicsUnit.Point, _
                CType(0, Byte))
            Me.Button2.Location = New System.Drawing.Point(521, 20)
            Me.Button2.Name = "Button2"
            Me.Button2.Size = New System.Drawing.Size(75, 24)
            Me.Button2.TabIndex = 3
            Me.Button2.Text = "E&xit"
            '
            'Panel1
            '
            Me.Panel1.Controls.Add(Me.tbxOutput)
            Me.Panel1.Dock = System.Windows.Forms.DockStyle.Fill
            Me.Panel1.DockPadding.All = 20
            Me.Panel1.Location = New System.Drawing.Point(0, 0)
            Me.Panel1.Name = "Panel1"
            Me.Panel1.Size = New System.Drawing.Size(616, 320)
            Me.Panel1.TabIndex = 2
            '
            'tbxOutput
            '
            Me.tbxOutput.AccessibleDescription = _
                "Displays output from application."
            Me.tbxOutput.AccessibleName = "Output textbox."
            Me.tbxOutput.Dock = System.Windows.Forms.DockStyle.Fill
            Me.tbxOutput.Location = New System.Drawing.Point(20, 20)
            Me.tbxOutput.Name = "tbxOutput"
            Me.tbxOutput.Size = New System.Drawing.Size(576, 280)
            Me.tbxOutput.TabIndex = 1
            Me.tbxOutput.Text = "Click the Run button to run the application."
            '
            'Form1
            '
            Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15)
            Me.ClientSize = New System.Drawing.Size(616, 384)
            Me.Controls.Add(Me.Panel1)
            Me.Controls.Add(Me.Panel2)
            Me.Name = "Form1"
            Me.Text = "AsymmetricAlgorithm"
            Me.Panel2.ResumeLayout(False)
            Me.Panel1.ResumeLayout(False)
            Me.ResumeLayout(False)

        End Sub

    End Class
End Namespace
'
' This sample produces the following output:
'
' *** CustomCrypto created with default parameters:
' Contoso.vbCustomCrypto
' KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
' SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
' KeySize: 8
' Parameters described in Xml format:
' <CustomCryptoKeyValue><KeyContainerName>SecurityBin1</KeyContainerName>
' <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
' <ProviderType>2</ProviderType></CustomCryptoKeyValue>
' Keysize0 min, max, step: 8, 64, 8, 
' 
' *** CustomCrypto created with custom parameters:
' Contoso.vbCustomCrypto
' KeyExchangeAlgorithm: RSA-PKCS1-KeyEx
' SignatureAlgorithm: http://www.w3.org/2000/09/xmldsig#rsa-sha1
' KeySize: 64
' Parameters described in Xml format:
' <CustomCryptoKeyValue><KeyContainerName>SecurityBin2</KeyContainerName>
' <KeyNumber>1</KeyNumber><ProviderName>Contoso</ProviderName>
' <ProviderType>2</ProviderType></CustomCryptoKeyValue>
' Keysize0 min, max, step: 8, 64, 8, 
' Unable to create CustomCrytpo from  the Create method
' This sample completed successfully; press Enter to exit.

備註

非對稱式密碼編譯演算法(也稱為公開金鑰演算法)要求傳送者和接收者都必須維護一組相關的金鑰:私密金鑰和公開金鑰。Asymmetric cryptographic algorithms, also known as public-key algorithms, require that both sender and receiver maintain a pair of related keys: a private key and a public key. 這兩個金鑰組實體而言是唯一的。Both keys are unique to the entity. 公開金鑰可供任何人使用;這個金鑰是用來編碼傳送至接收者的資料。The public key can be made available to anyone; this key is used for encoding data that is sent to a receiver. 私用金鑰必須由接收者保密;這個金鑰是用來解碼使用接收者的公開金鑰編碼的訊息。The private key must be kept private by the receiver; this key is used for decoding messages encoded using the receiver's public key. RSACryptoServiceProvider類別是公用金鑰演算法的執行。The RSACryptoServiceProvider class is an implementation of a public-key algorithm. 如需公開金鑰加密和演算法的深入討論,請參閱密碼編譯服務中的「公開金鑰加密」一節。For an in-depth discussion of public-key encryption and algorithms, see the "Public-Key Encryption" section in Cryptographic Services. 如需如何使用強式名稱工具(sn.exe)建立金鑰組的詳細資訊,請參閱如何:建立公開/私密金鑰組For information about how to use the Strong Name tool (Sn.exe) to create key pairs, see How to: Create a Public-Private Key Pair.

您可以使用公用金鑰系統來形成數位簽章。You can use public-key systems to form digital signatures. 數位簽章是用來協助保護資料的完整性。Digital signatures are used to help to protect the integrity of data. 例如,若要使用公開金鑰系統來數位簽署訊息,寄件者會先將雜湊函式套用至訊息,以建立訊息摘要。For example, to use a public-key system to digitally sign a message, the sender first applies a hash function to the message to create a message digest. 接著,傳送者會使用寄件者的私密金鑰來加密訊息摘要,以建立寄件者的個人簽章。The sender then encrypts the message digest with the sender's private key to create the sender's personal signature. 接收訊息和簽章時,接收者會使用寄件者的公開金鑰來解密簽名碼,以復原訊息摘要,並使用傳送者所使用的相同雜湊演算法來雜湊訊息。Upon receiving the message and signature, the receiver decrypts the signature using the sender's public key to recover the message digest and hashes the message using the same hash algorithm that the sender used. 如果接收者所計算的訊息摘要符合從傳送者接收的訊息摘要,則接收者可以假設訊息在傳輸過程中未遭到變更。If the message digest that the receiver computes matches the message digest received from the sender, the receiver can assume that the message was not altered while in transit. 請注意,任何人都可以驗證簽章,因為寄件者的公開金鑰是常見的知識。Note that anyone can verify a signature, because the sender's public key is common knowledge. 這項技術不會保留訊息的秘密;若要讓訊息成為秘密,也必須加密。This technique does not retain the secrecy of the message; for the message to be secret, it must also be encrypted.

.NET Framework 提供下列實作為數位簽章演算法的類別DSACryptoServiceProvider:、 RSACryptoServiceProviderECDsa (基類)和ECDsaCngThe .NET Framework provides the following classes that implement digital signature algorithms: DSACryptoServiceProvider, RSACryptoServiceProvider, ECDsa (base class), and ECDsaCng.

命名空間只會針對和RSA DSA提供具體的類別。 System.Security.CryptographyThe System.Security.Cryptography namespace provides concrete classes for RSA and DSA only.

若要瞭解如何使用 RSA 演算法來加密和解密 XML 資料,以及建立和驗證 XML 數位簽章,請參閱下列文章:To learn how to use the RSA algorithm to encrypt and decrypt XML data, and create and verify XML digital signatures, see these articles:

建構函式

AsymmetricAlgorithm()

初始化 AsymmetricAlgorithm 類別的新執行個體。Initializes a new instance of the AsymmetricAlgorithm class.

欄位

KeySizeValue

表示非對稱演算法使用的金鑰模數大小,以位元為單位。Represents the size, in bits, of the key modulus used by the asymmetric algorithm.

LegalKeySizesValue

指定非對稱演算法所支援的金鑰大小。Specifies the key sizes that are supported by the asymmetric algorithm.

屬性

KeyExchangeAlgorithm

在衍生類別中覆寫時,取得金鑰交換演算法的名稱。When overridden in a derived class, gets the name of the key exchange algorithm. 否則,擲回 NotImplementedExceptionOtherwise, throws an NotImplementedException.

KeySize

取得或設定非對稱演算法使用的金鑰模數大小,以位元為單位。Gets or sets the size, in bits, of the key modulus used by the asymmetric algorithm.

LegalKeySizes

取得非對稱演算法所支援的金鑰大小。Gets the key sizes that are supported by the asymmetric algorithm.

SignatureAlgorithm

在衍生類別中實作時,取得簽章演算法的名稱。When implemented in a derived class, gets the name of the signature algorithm. 否則,一律擲回 NotImplementedExceptionOtherwise, always throws a NotImplementedException.

方法

Clear()

釋放 AsymmetricAlgorithm 類別所使用的所有資源。Releases all resources used by the AsymmetricAlgorithm class.

Create()

建立用來執行非對稱演算法的預設密碼編譯物件。Creates a default cryptographic object used to perform the asymmetric algorithm.

Create(String)

建立非對稱演算法之指定實作的執行個體。Creates an instance of the specified implementation of an asymmetric algorithm.

Dispose()

釋放 AsymmetricAlgorithm 類別目前的執行個體所使用的全部資源。Releases all resources used by the current instance of the AsymmetricAlgorithm class.

Dispose(Boolean)

釋放 AsymmetricAlgorithm 類別所使用的 Unmanaged 資源,並選擇性地釋放 Managed 資源。Releases the unmanaged resources used by the AsymmetricAlgorithm class and optionally releases the managed resources.

Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

(繼承來源 Object)
ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters)

使用位元組型密碼以 PKCS#8 EncryptedPrivateKeyInfo 格式匯出目前金鑰。Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a byte-based password.

ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters)

使用 Char 型密碼以 PKCS#8 EncryptedPrivateKeyInfo 格式匯出目前金鑰。Exports the current key in the PKCS#8 EncryptedPrivateKeyInfo format with a char-based password.

ExportPkcs8PrivateKey()

以 PKCS#8 PrivateKeyInfo 格式匯出目前金鑰。Exports the current key in the PKCS#8 PrivateKeyInfo format.

ExportSubjectPublicKeyInfo()

以 X.509 SubjectPublicKeyInfo 格式匯出目前金鑰的公開金鑰部分。Exports the public-key portion of the current key in the X.509 SubjectPublicKeyInfo format.

FromXmlString(String)

在衍生類別中覆寫時,從 XML 字串重新建構 AsymmetricAlgorithm 物件。When overridden in a derived class, reconstructs an AsymmetricAlgorithm object from an XML string. 否則,擲回 NotImplementedExceptionOtherwise, throws a NotImplementedException.

GetHashCode()

做為預設雜湊函式。Serves as the default hash function.

(繼承來源 Object)
GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(繼承來源 Object)
ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Int32)

當在衍生類別中受到覆寫時,於使用位元組型密碼解密之後,從 PKCS#8 EncryptedPrivateKeyInfo 結構匯入公開/私密金鑰組,以取代這個物件的金鑰。When overridden in a derived class, imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a byte-based password, replacing the keys for this object.

ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, ReadOnlySpan<Byte>, Int32)

當在衍生類別中受到覆寫時,於使用字元型密碼解密之後,從 PKCS#8 EncryptedPrivateKeyInfo 結構匯入公開/私密金鑰組,以取代這個物件的金鑰。When overridden in a derived class, imports the public/private keypair from a PKCS#8 EncryptedPrivateKeyInfo structure after decrypting with a char-based password, replacing the keys for this object.

ImportPkcs8PrivateKey(ReadOnlySpan<Byte>, Int32)

當在衍生類別中受到覆寫時,於解密後從 PKCS#8 PrivateKeyInfo 結構匯入公開/私密金鑰組,以取代這個物件的金鑰。When overriden in a derived class, imports the public/private keypair from a PKCS#8 PrivateKeyInfo structure after decryption, replacing the keys for this object.

ImportSubjectPublicKeyInfo(ReadOnlySpan<Byte>, Int32)

當在衍生類別中受到覆寫時,於解密後從 X.509 SubjectPublicKeyInfo 結構匯入公開金鑰,以取代這個物件的金鑰。When overriden in a derived class, imports the public key from an X.509 SubjectPublicKeyInfo structure after decryption, replacing the keys for this object.

MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(繼承來源 Object)
ToXmlString(Boolean)

在衍生類別中覆寫時,建立並傳回目前 AsymmetricAlgorithm 物件的 XML 字串表示。When overridden in a derived class, creates and returns an XML string representation of the current AsymmetricAlgorithm object. 否則,擲回 NotImplementedExceptionOtherwise, throws a NotImplementedException.

TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters, Span<Byte>, Int32)

當在衍生類別中受到覆寫時,使用位元組型密碼嘗試以 PKCS#8 EncryptedPrivateKeyInfo 格式將目前的金鑰匯出至提供的緩衝區。When overridden in a derived class, attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a byte-based password.

TryExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters, Span<Byte>, Int32)

當在衍生類別中受到覆寫時,使用字元型密碼嘗試以 PKCS#8 EncryptedPrivateKeyInfo 格式將目前的金鑰匯出至提供的緩衝區。When overriden in a derived class, attempts to export the current key in the PKCS#8 EncryptedPrivateKeyInfo format into a provided buffer, using a char-based password.

TryExportPkcs8PrivateKey(Span<Byte>, Int32)

當在衍生類別中受到覆寫時,嘗試以 PKCS#8 PrivateKeyInfo 格式將目前的金鑰匯出至提供的緩衝區。When overridden in a derived class, attempts to export the current key in the PKCS#8 PrivateKeyInfo format into a provided buffer.

TryExportSubjectPublicKeyInfo(Span<Byte>, Int32)

當在衍生類別中受到覆寫時,嘗試以 X.509 SubjectPublicKeyInfo 格式將目前的金鑰匯出至提供的緩衝區。When overridden in a derived class, attempts to export the current key in the X.509 SubjectPublicKeyInfo format into a provided buffer.

明確介面實作

IDisposable.Dispose()

如需這個成員的說明,請參閱 Dispose()For a description of this member, see Dispose().

適用於

另請參閱