AesManaged.CreateDecryptor Metoda

  • Reference

Definice

Obor názvů:
System.Security.Cryptography
Sestavení:
System.Security.Cryptography.Algorithms.dll
Sestavení:
System.Security.Cryptography.dll
Sestavení:
System.Core.dll
Sestavení:
netstandard.dll

Vytvoří symetrický dešifrovací objekt.

Přetížení

CreateDecryptor()

Vytvoří symetrický dešifrovací objekt pomocí aktuálního klíče a inicializačního vektoru (IV).
CreateDecryptor(Byte[], Byte[])

Vytvoří symetrický dešifrovací objekt pomocí zadaného klíče a inicializačního vektoru (IV).

CreateDecryptor()

Vytvoří symetrický dešifrovací objekt pomocí aktuálního klíče a inicializačního vektoru (IV).

public:
 override System::Security::Cryptography::ICryptoTransform ^ CreateDecryptor();
public override System.Security.Cryptography.ICryptoTransform CreateDecryptor ();
override this.CreateDecryptor : unit -> System.Security.Cryptography.ICryptoTransform
Public Overrides Function CreateDecryptor () As ICryptoTransform

Návraty

ICryptoTransform

Symetrický dešifrovací objekt.

Platí pro

CreateDecryptor(Byte[], Byte[])

Vytvoří symetrický dešifrovací objekt pomocí zadaného klíče a inicializačního vektoru (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);
public override System.Security.Cryptography.ICryptoTransform CreateDecryptor (byte[] key, byte[] iv);
override this.CreateDecryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransform
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

Parametry

rgbKeykey
Byte[]

Tajný klíč, který se má použít pro symetrický algoritmus.

rgbIViv
Byte[]

Vektor inicializace, který se má použít pro symetrický algoritmus.

Návraty

ICryptoTransform

Symetrický dešifrovací objekt.

Výjimky

ArgumentNullException

key nebo iv je null.

ArgumentException

Formát key je neplatný.

Příklady

Následující příklad ukazuje, jak použít metodu AesManaged.CreateDecryptor k dešifrování šifrované zprávy. Tento příklad kódu je součástí většího příkladu zadaného AesManaged pro třídu.

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 AesManaged object
    // with the specified key and IV.
    using (AesManaged aesAlg = new AesManaged())
    {
        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 AesManaged object
        ' with the specified key and IV.
        Using aesAlg As New AesManaged
            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 AesManaged object
    // with the specified key and IV.
    use aesAlg = new AesManaged()
    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()

Platí pro