RSAOAEPKeyExchangeDeformatter クラス

定義

OAEP (Optimal Asymmetric Encryption Padding) キー交換データの暗号化を解除します。Decrypts Optimal Asymmetric Encryption Padding (OAEP) key exchange data.

public ref class RSAOAEPKeyExchangeDeformatter : System::Security::Cryptography::AsymmetricKeyExchangeDeformatter
[System.Runtime.InteropServices.ComVisible(true)]
public class RSAOAEPKeyExchangeDeformatter : System.Security.Cryptography.AsymmetricKeyExchangeDeformatter
type RSAOAEPKeyExchangeDeformatter = class
    inherit AsymmetricKeyExchangeDeformatter
Public Class RSAOAEPKeyExchangeDeformatter
Inherits AsymmetricKeyExchangeDeformatter
継承
RSAOAEPKeyExchangeDeformatter
属性

次の例は、クラスを使用RSAOAEPKeyExchangeDeformatterして、メッセージの復号化に使用する交換キーを再作成する方法を示しています。The following example shows how to use the RSAOAEPKeyExchangeDeformatter class to recreate an exchange key to be used to decrypt a message.

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

注釈

キー交換を使用すると、送信者は、対称暗号化アルゴリズムでキーとして使用できるランダムなデータなどのシークレット情報を作成し、暗号化を使用して目的の受信者に送信することができます。Key exchange allows a sender to create secret information, for example, random data that can be used as a key in a symmetric encryption algorithm, and use encryption to send it to the intended recipient.

RSAアルゴリズムを使用してキー交換メッセージを作成するには、を使用RSAOAEPKeyExchangeFormatterします。Use RSAOAEPKeyExchangeFormatter to create the key exchange message with the RSA algorithm.

注意事項

キー交換を成功させるには、操作の詳細情報を慎重に実行する必要があるため、提供されている基本的な機能から独自のキー交換メソッドを作成しないことを強くお勧めします。It is highly recommended that you not attempt to create your own key exchange method from the basic functionality provided, because many details of the operation must be performed carefully in order for the key exchange to be successful.

コンストラクター

RSAOAEPKeyExchangeDeformatter()

RSAOAEPKeyExchangeDeformatter クラスの新しいインスタンスを初期化します。Initializes a new instance of the RSAOAEPKeyExchangeDeformatter class.

RSAOAEPKeyExchangeDeformatter(AsymmetricAlgorithm)

指定したキーで、RSAOAEPKeyExchangeDeformatter クラスの新しいインスタンスを初期化します。Initializes a new instance of the RSAOAEPKeyExchangeDeformatter class with the specified key.

プロパティ

Parameters

OAEP (Optimal Asymmetric Encryption Padding) キー交換のパラメーターを取得します。Gets the parameters for the Optimal Asymmetric Encryption Padding (OAEP) key exchange.

メソッド

DecryptKeyExchange(Byte[])

暗号化されたキー交換データから秘密情報を抽出します。Extracts secret information from the encrypted key exchange data.

Equals(Object)

指定されたオブジェクトが現在のオブジェクトと等しいかどうかを判定します。Determines whether the specified object is equal to the current object.

(継承元 Object)
GetHashCode()

既定のハッシュ関数として機能します。Serves as the default hash function.

(継承元 Object)
GetType()

現在のインスタンスの Type を取得します。Gets the Type of the current instance.

(継承元 Object)
MemberwiseClone()

現在の Object の簡易コピーを作成します。Creates a shallow copy of the current Object.

(継承元 Object)
SetKey(AsymmetricAlgorithm)

秘密情報の暗号化解除に使用する秘密キーを設定します。Sets the private key to use for decrypting the secret information.

ToString()

現在のオブジェクトを表す string を返します。Returns a string that represents the current object.

(継承元 Object)

適用対象

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