AsymmetricAlgorithm Třída

Definice

Představuje abstraktní základní třídu, ze které musí dědit všechny implementace asymetrických algoritmů.

public ref class AsymmetricAlgorithm abstract : IDisposable
public abstract class AsymmetricAlgorithm : IDisposable
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class AsymmetricAlgorithm : IDisposable
type AsymmetricAlgorithm = class
    interface IDisposable
[<System.Runtime.InteropServices.ComVisible(true)>]
type AsymmetricAlgorithm = class
    interface IDisposable
Public MustInherit Class AsymmetricAlgorithm
Implements IDisposable
Dědičnost
AsymmetricAlgorithm
Odvozené
Atributy
Implementuje

Příklady

Následující příklad kódu ukazuje, jak implementovat vlastní asymetrický algoritmus zděděný z AsymmetricAlgorithm třídy. Je k dispozici další třída, která ukazuje, jak používat vlastní třídu.

#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.
            // This example uses the SHA1 algorithm.
            // Due to collision problems with SHA1, Microsoft recommends SHA256 or better.

        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.
        // This example uses the SHA1 algorithm.
        // Due to collision problems with SHA1, Microsoft recommends SHA256 or better.
        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.
        ' This example uses the SHA1 algorithm.
        ' Due to collision problems with SHA1, Microsoft recommends SHA256 or better.
        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.

Tady je další třída, která ukazuje, jak používat vlastní třídu.

#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.

Poznámky

Asymetrické kryptografické algoritmy, označované také jako algoritmy veřejného klíče, vyžadují, aby odesílatel i příjemce udržovali dvojici souvisejících klíčů: privátní klíč a veřejný klíč. Oba klíče jsou pro entitu jedinečné. Veřejný klíč může být zpřístupněn komukoli; tento klíč se používá pro kódování dat odesílaných příjemci. Privátní klíč musí být příjemcem uchovány jako soukromé; tento klíč se používá k dekódování zpráv zakódovaných pomocí veřejného klíče příjemce. Třída RSACryptoServiceProvider je implementace algoritmu veřejného klíče. Podrobné informace o šifrování a algoritmech s veřejným klíčem najdete v části Šifrování veřejného klíče v tématu Kryptografické služby. Informace o použití nástroje Silné jméno (Sn.exe) k vytvoření párů klíčů najdete v tématu Postupy: Vytvoření páru klíčů Public-Private.

K vytvoření digitálních podpisů můžete použít systémy veřejného klíče. Digitální podpisy slouží k ochraně integrity dat. Pokud například chcete použít systém veřejného klíče k digitálnímu podepsání zprávy, použije odesílatel nejprve na zprávu hashovací funkci, aby vytvořil souhrn zpráv. Odesílatel pak zašifruje zprávu digest pomocí privátního klíče odesílatele, aby vytvořil osobní podpis odesílatele. Po přijetí zprávy a podpisu příjemce dešifruje podpis pomocí veřejného klíče odesílatele k obnovení hodnoty hash zprávy a hashuje zprávu pomocí stejného hash algoritmu, který použil odesílatel. Pokud hodnota hash zprávy, kterou příjemce vypočítá, odpovídá hodnotě hash zprávy přijaté od odesílatele, může příjemce předpokládat, že zpráva nebyla během přenosu změněna. Všimněte si, že podpis může ověřit kdokoli, protože veřejný klíč odesílatele je všeobecně známé. Tato technika nezachovává utajení zprávy; Aby zpráva byla tajná, musí být také zašifrovaná.

Rozhraní .NET Framework poskytuje následující třídy, které implementují algoritmy digitálního podpisu: DSACryptoServiceProvider, RSACryptoServiceProvider( ECDsa základní třída) a ECDsaCng.

Obor System.Security.Cryptography názvů poskytuje konkrétní třídy pouze pro RSA a DSA .

Informace o použití algoritmu RSA k šifrování a dešifrování dat XML a vytváření a ověřování digitálních podpisů XML najdete v těchto článcích:

Konstruktory

AsymmetricAlgorithm()

Inicializuje novou instanci AsymmetricAlgorithm třídy.

Pole

KeySizeValue

Představuje velikost v bitech modulu klíče používaného asymetrickým algoritmem.

LegalKeySizesValue

Určuje velikosti klíčů podporované asymetrickým algoritmem.

Vlastnosti

KeyExchangeAlgorithm

Při přepsání v odvozené třídě získá název algoritmu výměny klíčů. V opačném případě vyvolá .NotImplementedException

KeySize

Získá nebo nastaví velikost v bitech modulu klíče používaného asymetrickým algoritmem.

LegalKeySizes

Získá velikosti klíčů, které jsou podporovány asymetrickým algoritmem.

SignatureAlgorithm

Při implementaci v odvozené třídě získá název algoritmu podpisu. V opačném případě vždy vyvolá NotImplementedException.

Metody

Clear()

Uvolní všechny prostředky používané AsymmetricAlgorithm třídou.

Create()
Zastaralé.
Zastaralé.

Vytvoří výchozí kryptografický objekt použitý k provedení asymetrického algoritmu.

Create(String)
Zastaralé.

Vytvoří instanci zadané implementace asymetrického algoritmu.

Dispose()

Uvolní všechny prostředky používané aktuální instancí AsymmetricAlgorithm třídy.

Dispose(Boolean)

Uvolní nespravované prostředky používané AsymmetricAlgorithm třídou a volitelně uvolní spravované prostředky.

Equals(Object)

Určí, zda se zadaný objekt rovná aktuálnímu objektu.

(Zděděno od Object)
ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, PbeParameters)

Exportuje aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na bajtech.

ExportEncryptedPkcs8PrivateKey(ReadOnlySpan<Char>, PbeParameters)

Exportuje aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na znaku.

ExportEncryptedPkcs8PrivateKeyPem(ReadOnlySpan<Byte>, PbeParameters)

Exportuje aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na bajtech s kódováním PEM.

ExportEncryptedPkcs8PrivateKeyPem(ReadOnlySpan<Char>, PbeParameters)

Exportuje aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na znaku s kódováním PEM.

ExportPkcs8PrivateKey()

Exportuje aktuální klíč ve formátu PKCS#8 PrivateKeyInfo.

ExportPkcs8PrivateKeyPem()

Exportuje aktuální klíč ve formátu PKCS#8 PrivateKeyInfo s kódováním PEM.

ExportSubjectPublicKeyInfo()

Exportuje část veřejného klíče aktuálního klíče ve formátu X.509 SubjectPublicKeyInfo.

ExportSubjectPublicKeyInfoPem()

Exportuje část veřejného klíče aktuálního klíče ve formátu X.509 SubjectPublicKeyInfo s kódováním PEM.

FromXmlString(String)

Při přepsání v odvozené třídě rekonstruuje AsymmetricAlgorithm objekt z řetězce XML. V opačném případě vyvolá NotImplementedException.

GetHashCode()

Slouží jako výchozí hashovací funkce.

(Zděděno od Object)
GetType()

Získá aktuální Type instanci.

(Zděděno od Object)
ImportEncryptedPkcs8PrivateKey(ReadOnlySpan<Byte>, ReadOnlySpan<Byte>, Int32)

Při přepsání v odvozené třídě importuje veřejný/privátní klíčpair ze struktury PKCS#8 EncryptedPrivateKeyInfo po dešifrování heslem založeným na bajtech a nahradí klíče pro tento objekt.

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

Při přepsání v odvozené třídě importuje veřejný/privátní klíčpair ze struktury PKCS#8 EncryptedPrivateKeyInfo po dešifrování heslem založeným na znaku a nahradí klíče pro tento objekt.

ImportFromEncryptedPem(ReadOnlySpan<Char>, ReadOnlySpan<Byte>)

Při přepsání v odvozené třídě importuje šifrovaný klíč RFC 7468 S KÓDOVÁNÍM PEM a nahradí klíče pro tento objekt.

ImportFromEncryptedPem(ReadOnlySpan<Char>, ReadOnlySpan<Char>)

Při přepsání v odvozené třídě importuje šifrovaný klíč RFC 7468 S KÓDOVÁNÍM PEM a nahradí klíče pro tento objekt.

ImportFromPem(ReadOnlySpan<Char>)

Při přepsání v odvozené třídě importuje textově zakódovaný klíč RFC 7468 a nahradí klíče pro tento objekt.

ImportPkcs8PrivateKey(ReadOnlySpan<Byte>, Int32)

Při přepsání v odvozené třídě importuje veřejný/privátní klíčpair ze struktury PKCS#8 PrivateKeyInfo po dešifrování a nahradí klíče pro tento objekt.

ImportSubjectPublicKeyInfo(ReadOnlySpan<Byte>, Int32)

Při přepsání v odvozené třídě importuje veřejný klíč ze struktury X.509 SubjectPublicKeyInfo po dešifrování a nahradí klíče pro tento objekt.

MemberwiseClone()

Vytvoří mělkou kopii aktuálního Objectsouboru .

(Zděděno od Object)
ToString()

Vrátí řetězec, který představuje aktuální objekt.

(Zděděno od Object)
ToXmlString(Boolean)

Při přepsání v odvozené třídě vytvoří a vrátí řetězcovou reprezentaci XML aktuálního AsymmetricAlgorithm objektu. V opačném případě vyvolá NotImplementedException.

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

Při přepsání v odvozené třídě se pokusí exportovat aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo do poskytnuté vyrovnávací paměti pomocí hesla založeného na bajtech.

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

Při přepsání v odvozené třídě se pokusí exportovat aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo do zadané vyrovnávací paměti pomocí hesla založeného na znaku.

TryExportEncryptedPkcs8PrivateKeyPem(ReadOnlySpan<Byte>, PbeParameters, Span<Char>, Int32)

Pokusí se exportovat aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na bajtech s kódováním PEM.

TryExportEncryptedPkcs8PrivateKeyPem(ReadOnlySpan<Char>, PbeParameters, Span<Char>, Int32)

Exportuje aktuální klíč ve formátu PKCS#8 EncryptedPrivateKeyInfo s heslem založeným na znaku s kódováním PEM.

TryExportPkcs8PrivateKey(Span<Byte>, Int32)

Při přepsání v odvozené třídě se pokusí exportovat aktuální klíč ve formátu PKCS#8 PrivateKeyInfo do poskytnuté vyrovnávací paměti.

TryExportPkcs8PrivateKeyPem(Span<Char>, Int32)

Pokusí se exportovat aktuální klíč ve formátu PKCS#8 PrivateKeyInfo s kódováním PEM do poskytnuté vyrovnávací paměti.

TryExportSubjectPublicKeyInfo(Span<Byte>, Int32)

Při přepsání v odvozené třídě se pokusí exportovat aktuální klíč ve formátu X.509 SubjectPublicKeyInfo do poskytnuté vyrovnávací paměti.

TryExportSubjectPublicKeyInfoPem(Span<Char>, Int32)

Pokusí se exportovat aktuální klíč ve formátu X.509 SubjectPublicKeyInfo s kódováním PEM do poskytnuté vyrovnávací paměti.

Explicitní implementace rozhraní

IDisposable.Dispose()

Toto rozhraní API podporuje produktovou infrastrukturu a není určené k použití přímo z uživatelského kódu.

Popis tohoto člena najdete v tématu Dispose().

Platí pro

Viz také