RSAOAEPKeyExchangeDeformatter Třída

Definice

public ref class RSAOAEPKeyExchangeDeformatter : System::Security::Cryptography::AsymmetricKeyExchangeDeformatter

[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public class RSAOAEPKeyExchangeDeformatter : System.Security.Cryptography.AsymmetricKeyExchangeDeformatter

public class RSAOAEPKeyExchangeDeformatter : System.Security.Cryptography.AsymmetricKeyExchangeDeformatter

[System.Runtime.InteropServices.ComVisible(true)]
public class RSAOAEPKeyExchangeDeformatter : System.Security.Cryptography.AsymmetricKeyExchangeDeformatter

[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
type RSAOAEPKeyExchangeDeformatter = class
    inherit AsymmetricKeyExchangeDeformatter

type RSAOAEPKeyExchangeDeformatter = class
    inherit AsymmetricKeyExchangeDeformatter

[<System.Runtime.InteropServices.ComVisible(true)>]
type RSAOAEPKeyExchangeDeformatter = class
    inherit AsymmetricKeyExchangeDeformatter

Public Class RSAOAEPKeyExchangeDeformatter
Inherits AsymmetricKeyExchangeDeformatter

Dědičnost

Object

AsymmetricKeyExchangeDeformatter

RSAOAEPKeyExchangeDeformatter

Atributy

UnsupportedOSPlatformAttribute ComVisibleAttribute

Příklady

Následující příklad ukazuje, jak použít RSAOAEPKeyExchangeDeformatter třídu k opětovnému vytvoření klíče exchange, který se má použít k dešifrování zprávy.

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

class Alice
{
    public static void Main(string[] args)
    {
        using (Bob bob = new Bob())
        {
            using (RSACryptoServiceProvider rsaKey = new RSACryptoServiceProvider())
            {
                // Get Bob's public key
                rsaKey.ImportCspBlob(bob.key);
                byte[] encryptedSessionKey = null;
                byte[] encryptedMessage = null;
                byte[] iv = null;
                Send(rsaKey, "Secret message", out iv, out encryptedSessionKey, out encryptedMessage);
                bob.Receive(iv, encryptedSessionKey, encryptedMessage);
            }
        }
    }

    private static void Send(RSA key, string secretMessage, out byte[] iv, out byte[] encryptedSessionKey, out byte[] encryptedMessage)
    {
        using (Aes aes = new AesCryptoServiceProvider())
        {
            iv = aes.IV;

            // Encrypt the session key
            RSAOAEPKeyExchangeFormatter keyFormatter = new RSAOAEPKeyExchangeFormatter(key);
            encryptedSessionKey = keyFormatter.CreateKeyExchange(aes.Key, typeof(Aes));

            // Encrypt the message
            using (MemoryStream ciphertext = new MemoryStream())
            using (CryptoStream cs = new CryptoStream(ciphertext, aes.CreateEncryptor(), CryptoStreamMode.Write))
            {
                byte[] plaintextMessage = Encoding.UTF8.GetBytes(secretMessage);
                cs.Write(plaintextMessage, 0, plaintextMessage.Length);
                cs.Close();

                encryptedMessage = ciphertext.ToArray();
            }
        }
    }
}
public class Bob : IDisposable
{
    public byte[] key;
    private RSACryptoServiceProvider rsaKey = new RSACryptoServiceProvider();
    public Bob()
    {
        key = rsaKey.ExportCspBlob(false);
    }
    public void Receive(byte[] iv, byte[] encryptedSessionKey, byte[] encryptedMessage)
    {

        using (Aes aes = new AesCryptoServiceProvider())
        {
            aes.IV = iv;

            // Decrypt the session key
            RSAOAEPKeyExchangeDeformatter keyDeformatter = new RSAOAEPKeyExchangeDeformatter(rsaKey);
            aes.Key = keyDeformatter.DecryptKeyExchange(encryptedSessionKey);

            // Decrypt the message
            using (MemoryStream plaintext = new MemoryStream())
            using (CryptoStream cs = new CryptoStream(plaintext, aes.CreateDecryptor(), CryptoStreamMode.Write))
            {
                cs.Write(encryptedMessage, 0, encryptedMessage.Length);
                cs.Close();

                string message = Encoding.UTF8.GetString(plaintext.ToArray());
                Console.WriteLine(message);
            }
        }
    }
    public void Dispose()
    {
        rsaKey.Dispose();
    }
}

Imports System.IO
Imports System.Security.Cryptography
Imports System.Text




Class Alice

    Public Shared Sub Main(ByVal args() As String)
        Using bob As New Bob()
            Using rsaKey As New RSACryptoServiceProvider()
                    ' Get Bob's public key
                    rsaKey.ImportCspBlob(bob.key)
                    Dim encryptedSessionKey As Byte() = Nothing
                    Dim encryptedMessage As Byte() = Nothing
                    Dim iv As Byte() = Nothing
                    Send(rsaKey, "Secret message", iv, encryptedSessionKey, encryptedMessage)
                    bob.Receive(iv, encryptedSessionKey, encryptedMessage)
            End Using
        End Using

    End Sub


    Private Shared Sub Send(ByVal key As RSA, ByVal secretMessage As String, ByRef iv() As Byte, ByRef encryptedSessionKey() As Byte, ByRef encryptedMessage() As Byte)
        Using aes = New AesCryptoServiceProvider()

            iv = aes.IV

            ' Encrypt the session key
            Dim keyFormatter As New RSAOAEPKeyExchangeFormatter(key)
            encryptedSessionKey = keyFormatter.CreateKeyExchange(aes.Key, GetType(Aes))

            ' Encrypt the message
            Using ciphertext As New MemoryStream()
                Using cs As New CryptoStream(ciphertext, aes.CreateEncryptor(), CryptoStreamMode.Write)
                    Dim plaintextMessage As Byte() = Encoding.UTF8.GetBytes(secretMessage)
                    cs.Write(plaintextMessage, 0, plaintextMessage.Length)
                    cs.Close()

                    encryptedMessage = ciphertext.ToArray()
                End Using
            End Using
        End Using

    End Sub
End Class

Public Class Bob
    Implements IDisposable
    Public key() As Byte
    Private rsaKey As New RSACryptoServiceProvider()

    Public Sub New()
        key = rsaKey.ExportCspBlob(False)

    End Sub

    Public Sub Receive(ByVal iv() As Byte, ByVal encryptedSessionKey() As Byte, ByVal encryptedMessage() As Byte)

        Using aes = New AesCryptoServiceProvider()

            aes.IV = iv

            ' Decrypt the session key
            Dim keyDeformatter As New RSAOAEPKeyExchangeDeformatter(rsaKey)
            aes.Key = keyDeformatter.DecryptKeyExchange(encryptedSessionKey)

            ' Decrypt the message
            Using plaintext As New MemoryStream()
                Using cs As New CryptoStream(plaintext, aes.CreateDecryptor(), CryptoStreamMode.Write)
                        cs.Write(encryptedMessage, 0, encryptedMessage.Length)
                        cs.Close()

                        Dim message As String = Encoding.UTF8.GetString(plaintext.ToArray())
                        Console.WriteLine(message)
                End Using
            End Using
        End Using

    End Sub
    Public Overloads Sub Dispose() Implements IDisposable.Dispose
        rsaKey.Dispose()
    End Sub
End Class

Poznámky

Výměna klíčů umožňuje odesílateli vytvořit tajné informace, například náhodná data, která lze použít jako klíč v algoritmu symetrického šifrování, a pomocí šifrování je odeslat zamýšlenému příjemci.

Slouží RSAOAEPKeyExchangeFormatter k vytvoření zprávy výměny klíčů s algoritmem RSA .

Konstruktory

Vlastnosti

Metody

Platí pro

Viz také

• Šifrovací služby