.NET Framework Class Library
RijndaelManaged..::.CreateEncryptor Method (array<Byte>[]()[], array<Byte>[]()[])

Creates a symmetric Rijndael encryptor object with the specified Key and initialization vector (IV).

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)
Syntax

Visual Basic (Declaration)
Public Overrides Function CreateEncryptor ( _
    rgbKey As Byte(), _
    rgbIV As Byte() _
) As ICryptoTransform
Visual Basic (Usage)
Dim instance As RijndaelManaged
Dim rgbKey As Byte()
Dim rgbIV As Byte()
Dim returnValue As ICryptoTransform

returnValue = instance.CreateEncryptor(rgbKey, _
    rgbIV)
C#
public override ICryptoTransform CreateEncryptor(
    byte[] rgbKey,
    byte[] rgbIV
)
Visual C++
public:
virtual ICryptoTransform^ CreateEncryptor(
    array<unsigned char>^ rgbKey, 
    array<unsigned char>^ rgbIV
) override
JScript
public override function CreateEncryptor(
    rgbKey : byte[], 
    rgbIV : byte[]
) : ICryptoTransform

Parameters

rgbKey
Type: array<System..::.Byte>[]()[]
The secret key to be used for the symmetric algorithm. The key size must be 126, 128, or 256 bits.
rgbIV
Type: array<System..::.Byte>[]()[]
The IV to be used for the symmetric algorithm.

Return Value

Type: System.Security.Cryptography..::.ICryptoTransform
A symmetric Rijndael encryptor object.
Exceptions

ExceptionCondition
ArgumentNullException

The rgbKey parameter is nullNothingnullptra null reference (Nothing in Visual Basic).

-or-

The rgbIV parameter is nullNothingnullptra null reference (Nothing in Visual Basic).

CryptographicException

The value of the Mode parameter is not ECB, CBC, or CFB.

Remarks

Use the CreateDecryptor overload with the same signature to decrypt the result of this method.

The rgbkey size must be 126, 128, or 256 bits.

Examples

The following code examples demonstrates how to encrypt a message using the CreateEncryptor method.

Visual Basic
Imports System
Imports System.IO
Imports System.Security.Cryptography



Module RijndaelMemoryExample

    Sub Main()
        Try

            Dim original As String = "Here is some data to encrypt!"

            ' Create a new instance of the RijndaelManaged
            ' class.  This generates a new key and initialization 
            ' vector (IV).
            Dim myRijndael As New RijndaelManaged()

            ' Encrypt the string to an array of bytes.
            Dim encrypted As Byte() = encryptStringToBytes_AES(original, myRijndael.Key, myRijndael.IV)

            ' Decrypt the bytes to a string.
            Dim roundtrip As String = decryptStringFromBytes_AES(encrypted, myRijndael.Key, myRijndael.IV)

            'Display the original data and the decrypted data.
            Console.WriteLine("Original:   {0}", original)
            Console.WriteLine("Round Trip: {0}", roundtrip)

        Catch e As Exception
            Console.WriteLine("Error: {0}", e.Message)
        End Try

    End Sub


    Function encryptStringToBytes_AES(ByVal plainText As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()
        ' Check arguments.
        If plainText Is Nothing OrElse plainText.Length <= 0 Then
            Throw New ArgumentNullException("plainText")
        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("Key")
        End If

        ' Declare the RijndaelManaged object
        ' used to encrypt the data.
        Dim aesAlg As RijndaelManaged = Nothing

        ' Declare the stream used to encrypt to an in memory
        ' array of bytes.
        Dim msEncrypt As MemoryStream = Nothing

        Try
            ' Create a RijndaelManaged object
            ' with the specified key and IV.
            aesAlg = New RijndaelManaged()
            aesAlg.Key = Key
            aesAlg.IV = IV

            ' Create a decrytor to perform the stream transform.
            Dim encryptor As ICryptoTransform = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV)

            ' Create the streams used for encryption.
            msEncrypt = New MemoryStream()
            Using csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
                Using swEncrypt As New StreamWriter(csEncrypt)

                    'Write all data to the stream.
                    swEncrypt.Write(plainText)
                End Using
            End Using

        Finally
            ' Clear the RijndaelManaged object.
            If Not (aesAlg Is Nothing) Then
                aesAlg.Clear()
            End If
        End Try
        ' Return the encrypted bytes from the memory stream.
        Return msEncrypt.ToArray()

    End Function


    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("Key")
        End If

        ' Declare the RijndaelManaged object
        ' used to decrypt the data.
        Dim aesAlg As RijndaelManaged = Nothing

        ' Declare the string used to hold
        ' the decrypted text.
        Dim plaintext As String = Nothing

        Try
            ' Create a RijndaelManaged object
            ' with the specified key and IV.
            aesAlg = New RijndaelManaged()
            aesAlg.Key = Key
            aesAlg.IV = IV

            ' Create a decrytor 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

        Finally

            ' Clear the RijndaelManaged object.
            If Not (aesAlg Is Nothing) Then
                aesAlg.Clear()
            End If
        End Try
        Return plaintext

    End Function
End Module
C#
using System;
using System.IO;
using System.Security.Cryptography;

namespace RijndaelManaged_Examples
{
    class RijndaelMemoryExample
    {
        public static void Main()
        {
            try
            {

                string original = "Here is some data to encrypt!";

                // Create a new instance of the RijndaelManaged
                // class.  This generates a new key and initialization 
                // vector (IV).
                RijndaelManaged myRijndael = new RijndaelManaged();

                // Encrypt the string to an array of bytes.
                byte[] encrypted = encryptStringToBytes_AES(original, myRijndael.Key, myRijndael.IV);

                // Decrypt the bytes to a string.
                string roundtrip = decryptStringFromBytes_AES(encrypted, myRijndael.Key, myRijndael.IV);

                //Display the original data and the decrypted data.
                Console.WriteLine("Original:   {0}", original);
                Console.WriteLine("Round Trip: {0}", roundtrip);

            }
            catch (Exception e)
            {
                Console.WriteLine("Error: {0}", e.Message);
            }
        }

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

            // Declare the stream used to encrypt to an in memory
            // array of bytes.
            MemoryStream msEncrypt = null;

            // Declare the RijndaelManaged object
            // used to encrypt the data.
            RijndaelManaged aesAlg = null;

            try
            {
                // Create a RijndaelManaged object
                // with the specified key and IV.
                aesAlg = new RijndaelManaged();
                aesAlg.Key = Key;
                aesAlg.IV = IV;

                // Create a decrytor to perform the stream transform.
                ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

                // Create the streams used for encryption.
                msEncrypt = new MemoryStream();
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {

                        //Write all data to the stream.
                        swEncrypt.Write(plainText);
                    }
                }

            }
            finally
            {

                // Clear the RijndaelManaged object.
                if (aesAlg != null)
                    aesAlg.Clear();
            }

            // Return the encrypted bytes from the memory stream.
            return msEncrypt.ToArray();

        }

        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("Key");

            // Declare the RijndaelManaged object
            // used to decrypt the data.
            RijndaelManaged aesAlg = null;

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

            try
            {
                // Create a RijndaelManaged object
                // with the specified key and IV.
                aesAlg = new RijndaelManaged();
                aesAlg.Key = Key;
                aesAlg.IV = IV;

                // Create a decrytor 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();
                    }
                }

            }
            finally
            {

                // Clear the RijndaelManaged object.
                if (aesAlg != null)
                    aesAlg.Clear();
            }

            return plaintext;

        }
    }
}
Visual C++
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Security::Cryptography;


class RijndaelMemoryExample
{
 public:
    static array<Byte> ^ encryptStringToBytes_AES(String^ plainText, array<Byte> ^ Key, array<Byte> ^ IV)
    {
        // Check arguments.
        if (!plainText || plainText->Length <= 0)
            throw gcnew ArgumentNullException("plainText");
        if (!Key || Key->Length <= 0)
            throw gcnew ArgumentNullException("Key");
        if (!IV  || IV->Length <= 0)
            throw gcnew ArgumentNullException("Key");

        // Declare the streams used
        // to encrypt to an in memory
        // array of bytes.
        MemoryStream ^   msEncrypt;
        CryptoStream ^   csEncrypt;
        StreamWriter ^   swEncrypt;

        // Declare the RijndaelManaged object
        // used to encrypt the data.
        RijndaelManaged ^ aesAlg;

        try
        {
            // Create a RijndaelManaged object
            // with the specified key and IV.
            aesAlg = gcnew RijndaelManaged();
            aesAlg->Padding = PaddingMode::PKCS7;
            aesAlg->Key = Key;
            aesAlg->IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform ^ encryptor = aesAlg->CreateEncryptor(aesAlg->Key, aesAlg->IV);

            // Create the streams used for encryption.
            msEncrypt = gcnew MemoryStream();
            csEncrypt = gcnew CryptoStream(msEncrypt, encryptor, CryptoStreamMode::Write);
            swEncrypt = gcnew StreamWriter(csEncrypt);

            //Write all data to the stream.
            swEncrypt->Write(plainText);
            swEncrypt->Flush();
            csEncrypt->FlushFinalBlock();
            msEncrypt->Flush();

        }
        finally
        {
            // Clean things up.

            // Close the streams.
            if(swEncrypt)
                swEncrypt->Close();
            if (csEncrypt)
                csEncrypt->Close();


            // Clear the RijndaelManaged object.
            if (aesAlg)
                aesAlg->Clear();
        }

        // Return the encrypted bytes from the memory stream.
        return msEncrypt->ToArray();

    }

    static String ^ decryptStringFromBytes_AES(array<Byte> ^ cipherText, array<Byte> ^ Key, array<Byte> ^ IV)
    {
        // Check arguments.
        if (!cipherText || cipherText->Length <= 0)
            throw gcnew ArgumentNullException("cipherText");
        if (!Key || Key->Length <= 0)
            throw gcnew ArgumentNullException("Key");
        if (!IV || IV->Length <= 0)
            throw gcnew ArgumentNullException("Key");

        // TDeclare the streams used
        // to decrypt to an in memory
        // array of bytes.
        MemoryStream   ^ msDecrypt;
        CryptoStream   ^ csDecrypt;
        StreamReader   ^ srDecrypt;

        // Declare the RijndaelManaged object
        // used to decrypt the data.
        RijndaelManaged ^ aesAlg;

        // Declare the string used to hold
        // the decrypted text.
        String ^ plaintext;

        try
        {
            // Create a RijndaelManaged object
            // with the specified key and IV.
            aesAlg = gcnew RijndaelManaged();
            aesAlg->Padding = PaddingMode::PKCS7;
            aesAlg->Key = Key;
            aesAlg->IV = IV;

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

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

            // Read the decrypted bytes from the decrypting stream
            // and place them in a string.
            plaintext = srDecrypt->ReadToEnd();
        }
        finally
        {
            // Clean things up.

            // Close the streams.
            if (srDecrypt)
                srDecrypt->Close();
            if (csDecrypt)
                csDecrypt->Close();
            if (msDecrypt)
                msDecrypt->Close();

            // Clear the RijndaelManaged object.
            if (aesAlg)
                aesAlg->Clear();
        }

        return plaintext;

    }

};

int main()
{
    try
    {

        String ^ original = "Here is some data to encrypt!";

        // Create a new instance of the RijndaelManaged
        // class.  This generates a new key and initialization
        // vector (IV).
        RijndaelManaged ^ myRijndael = gcnew RijndaelManaged();

        // Encrypt the string to an array of bytes.
        array<Byte> ^ encrypted = RijndaelMemoryExample::encryptStringToBytes_AES(original, myRijndael->Key, myRijndael->IV);

        // Decrypt the bytes to a string.
        String ^ roundtrip = RijndaelMemoryExample::decryptStringFromBytes_AES(encrypted, myRijndael->Key, myRijndael->IV);

        //Display the original data and the decrypted data.
        Console::WriteLine("Original:   {0}", original);
        Console::WriteLine("Round Trip: {0}", roundtrip);

    }
    catch (Exception ^ e)
    {
        Console::WriteLine("Error: {0}", e->Message);
    }

    return 0;
}

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0
See Also

Reference

Other Resources

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