RSAOAEPKeyExchangeFormatter Clase

Definición

public ref class RSAOAEPKeyExchangeFormatter : System::Security::Cryptography::AsymmetricKeyExchangeFormatter

public class RSAOAEPKeyExchangeFormatter : System.Security.Cryptography.AsymmetricKeyExchangeFormatter

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

[System.Runtime.InteropServices.ComVisible(true)]
public class RSAOAEPKeyExchangeFormatter : System.Security.Cryptography.AsymmetricKeyExchangeFormatter

type RSAOAEPKeyExchangeFormatter = class
    inherit AsymmetricKeyExchangeFormatter

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

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

Public Class RSAOAEPKeyExchangeFormatter
Inherits AsymmetricKeyExchangeFormatter

Herencia

Object

AsymmetricKeyExchangeFormatter

RSAOAEPKeyExchangeFormatter

Atributos

UnsupportedOSPlatformAttribute ComVisibleAttribute

Ejemplos

En el ejemplo siguiente se muestra cómo usar la RSAOAEPKeyExchangeFormatter clase para crear una clave de intercambio para un destinatario del mensaje.

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

Comentarios

El intercambio de claves permite a un remitente crear información secreta, por ejemplo, datos aleatorios que se pueden usar como clave en un algoritmo de cifrado simétrico y usar el cifrado para enviarlo al destinatario previsto.

Use RSAOAEPKeyExchangeDeformatter para recibir el intercambio de claves y extraer la información secreta de ella.

Consulte también

• Servicios criptográficos