AesCryptoServiceProvider.CreateDecryptor Methode

Definition

Namespace:

System.Security.Cryptography

Assembly:

System.Security.Cryptography.Csp.dll

Assembly:

System.Security.Cryptography.dll

Assembly:

System.Core.dll

Assembly:

netstandard.dll

Erstellt ein symmetrisches AES-Entschlüsselungsobjekt.

Überlädt

CreateDecryptor()	Erstellt ein symmetrisches AES-Entschlüsselungsobjekt mit dem aktuellen Schlüssel und Initialisierungsvektor (IV).
CreateDecryptor(Byte[], Byte[])	Erstellt ein symmetrisches AES-Entschlüsselungsobjekt mit dem angegebenen Schlüssel und Initialisierungsvektor (IV).

CreateDecryptor()

Erstellt ein symmetrisches AES-Entschlüsselungsobjekt mit dem aktuellen Schlüssel und Initialisierungsvektor (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor();

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor ();

[System.Security.SecurityCritical]
public override System.Security.Cryptography.ICryptoTransform CreateDecryptor ();

override this.CreateDecryptor : unit -> System.Security.Cryptography.ICryptoTransform

[<System.Security.SecurityCritical>]
override this.CreateDecryptor : unit -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateDecryptor () As ICryptoTransform

Gibt zurück

ICryptoTransform

Ein symmetrisches AES-Entschlüsselungsobjekt.

Attribute

SecurityCriticalAttribute

Ausnahmen

CryptographicException

Der aktuelle Schlüssel ist ungültig oder fehlt.

CreateDecryptor(Byte[], Byte[])

Erstellt ein symmetrisches AES-Entschlüsselungsobjekt mit dem angegebenen Schlüssel und Initialisierungsvektor (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor(cli::array <System::Byte> ^ rgbKey, cli::array <System::Byte> ^ rgbIV);

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor(cli::array <System::Byte> ^ key, cli::array <System::Byte> ^ iv);

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[]? rgbIV);

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV);

[System.Security.SecurityCritical]
public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] key, byte[] iv);

public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] key, byte[] iv);

override this.CreateDecryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform

[<System.Security.SecurityCritical>]
override this.CreateDecryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform

Public Overrides Function CreateDecryptor (rgbKey As Byte(), rgbIV As Byte()) As ICryptoTransform

Public Overrides Function CreateDecryptor (key As Byte(), iv As Byte()) As ICryptoTransform

Parameter

rgbKeykey

Byte[]

Der geheime Schlüssel, der für den symmetrischen Algorithmus verwendet werden soll.

rgbIViv

Byte[]

Der Initialisierungsvektor, der für den symmetrischen Algorithmus verwendet werden soll.

Gibt zurück

ICryptoTransform

Ein symmetrisches AES-Entschlüsselungsobjekt.

Attribute

SecurityCriticalAttribute

Ausnahmen

ArgumentNullException

key oder iv ist null.

ArgumentException

key ist ungültig.

Beispiele

Im folgenden Beispiel wird gezeigt, wie Sie die AesCryptoServiceProvider.CreateDecryptor Methode verwenden, um eine verschlüsselte Nachricht zu entschlüsseln. Dieses Codebeispiel ist Teil eines größeren Beispiels, das für die AesCryptoServiceProvider Klasse bereitgestellt wird.

static string DecryptStringFromBytes_Aes(byte[] cipherText, byte[] Key, byte[] IV)
{
    // Check arguments.
    if (cipherText == null || cipherText.Length <= 0)
        throw new ArgumentNullException("cipherText");
    if (Key == null || Key.Length <= 0)
        throw new ArgumentNullException("Key");
    if (IV == null || IV.Length <= 0)
        throw new ArgumentNullException("IV");

    // Declare the string used to hold
    // the decrypted text.
    string plaintext = null;

    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
    {
        aesAlg.Key = Key;
        aesAlg.IV = IV;

        // Create a decryptor to perform the stream transform.
        ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

        // Create the streams used for decryption.
        using (MemoryStream msDecrypt = new MemoryStream(cipherText))
        {
            using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
            {
                using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                {

                    // Read the decrypted bytes from the decrypting stream
                    // and place them in a string.
                    plaintext = srDecrypt.ReadToEnd();
                }
            }
        }
    }

    return plaintext;
}

    Shared Function DecryptStringFromBytes_Aes(ByVal cipherText() As Byte,ByVal Key() As Byte, ByVal IV() As Byte) As String
        ' Check arguments.
        If cipherText Is Nothing OrElse cipherText.Length <= 0 Then
            Throw New ArgumentNullException("cipherText")
        End If
        If Key Is Nothing OrElse Key.Length <= 0 Then
            Throw New ArgumentNullException("Key")
        End If
        If IV Is Nothing OrElse IV.Length <= 0 Then
            Throw New ArgumentNullException("IV")
        End If
        ' Declare the string used to hold
        ' the decrypted text.
        Dim plaintext As String = Nothing

        ' Create an AesCryptoServiceProvider object
        ' with the specified key and IV.
        Using aesAlg As New AesCryptoServiceProvider()

            aesAlg.Key = Key
            aesAlg.IV = IV

            ' Create a decryptor to perform the stream transform.
            Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

            ' Create the streams used for decryption.
            Using msDecrypt As New MemoryStream(cipherText)

                Using csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)

                    Using srDecrypt As New StreamReader(csDecrypt)

                        ' Read the decrypted bytes from the decrypting stream
                        ' and place them in a string.
                        plaintext = srDecrypt.ReadToEnd()
                    End Using
                End Using
            End Using
        End Using
        Return plaintext

    End Function 'DecryptStringFromBytes_Aes 
End Class

let decryptStringFromBytes_Aes (cipherText : byte[], key : byte[], iv : byte[]) : string =

    // Check arguments.
    if (isNull cipherText || cipherText.Length <= 0) then nullArg "cipherText"
    if (isNull key || key.Length <= 0) then nullArg "key"
    if (isNull iv || iv.Length <= 0) then nullArg "iv"

    // Create an AesCryptoServiceProvider object
    // with the specified key and IV.
    use aesAlg = new AesCryptoServiceProvider()
    aesAlg.Key <- key
    aesAlg.IV <- iv

    // Create a decryptor to perform the stream transform.
    let decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)

    // Create the streams used for decryption.
    use msDecrypt = new MemoryStream(cipherText)
    use csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
    use srDecrypt = new StreamReader(csDecrypt)

    // Read the decrypted bytes from the decrypting stream
    // and return the resulting string.
    srDecrypt.ReadToEnd()