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 streams used
        ' to encrypt to an in memory
        ' array of bytes.
        Dim msEncrypt As MemoryStream = Nothing
        Dim csEncrypt As CryptoStream = Nothing
        Dim swEncrypt As StreamWriter = Nothing

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

        ' Declare the bytes used to hold the
        ' encrypted data.
        Dim encrypted As Byte() = 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()
            csEncrypt = New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
            swEncrypt = New StreamWriter(csEncrypt)

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

        Finally
            ' Clean things up.
            ' Close the streams.
            If Not (swEncrypt Is Nothing) Then
                swEncrypt.Close()
            End If
            If Not (csEncrypt Is Nothing) Then
                csEncrypt.Close()
            End If
            If Not (msEncrypt Is Nothing) Then
                msEncrypt.Close()
            End If
            ' 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
        ' TDeclare the streams used
        ' to decrypt to an in memory
        ' array of bytes.
        Dim msDecrypt As MemoryStream = Nothing
        Dim csDecrypt As CryptoStream = Nothing
        Dim srDecrypt As StreamReader = Nothing

        ' 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.
            msDecrypt = New MemoryStream(cipherText)
            csDecrypt = New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
            srDecrypt = New 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 Not (srDecrypt Is Nothing) Then
                srDecrypt.Close()
            End If
            If Not (csDecrypt Is Nothing) Then
                csDecrypt.Close()
            End If
            If Not (msDecrypt Is Nothing) Then
                msDecrypt.Close()
            End If
            ' Clear the RijndaelManaged object.
            If Not (aesAlg Is Nothing) Then
                aesAlg.Clear()
            End If
        End Try
        Return plaintext

    End Function
End Module

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 streams used
            // to encrypt to an in memory
            // array of bytes.
            MemoryStream    msEncrypt   = null;
            CryptoStream    csEncrypt   = null;
            StreamWriter    swEncrypt   = null;

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

            // Declare the bytes used to hold the
            // encrypted data.
            byte[]          encrypted   = 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();
                csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);
                swEncrypt = new StreamWriter(csEncrypt);

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

            }
            finally
            {
                // Clean things up.

                // Close the streams.
                if(swEncrypt != null)
                    swEncrypt.Close();
                if (csEncrypt != null)
                    csEncrypt.Close();
                if (msEncrypt != null)
                    msEncrypt.Close();

                // 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");

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

            // 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.
                msDecrypt = new MemoryStream(cipherText);
                csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);
                srDecrypt = new 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 != null)
                    srDecrypt.Close();
                if (csDecrypt != null)
                    csDecrypt.Close();
                if (msDecrypt != null)
                    msDecrypt.Close();

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

            return plaintext;

        }
    }
}

#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->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);

        }
        finally
        {
            // Clean things up.

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