AesManaged Class

Provides a managed implementation of the Advanced Encryption Standard (AES) symmetric algorithm.

Inheritance Hierarchy

System.Object
  System.Security.Cryptography.SymmetricAlgorithm
    System.Security.Cryptography.Aes
      System.Security.Cryptography.AesManaged

Namespace:  System.Security.Cryptography
Assembly:  System.Core (in System.Core.dll)

Syntax

'Declaration
Public NotInheritable Class AesManaged _
    Inherits Aes
public sealed class AesManaged : Aes

The AesManaged type exposes the following members.

Constructors

  Name Description
Public methodSupported by Silverlight for Windows Phone AesManaged Initializes a new instance of the AesManaged class.

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Properties

  Name Description
Public propertySupported by Silverlight for Windows Phone BlockSize Gets or sets the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Public propertySupported by Silverlight for Windows Phone IV Gets or sets the initialization vector (IV) to use for the symmetric algorithm. (Overrides SymmetricAlgorithm.IV.)
Public propertySupported by Silverlight for Windows Phone Key Gets or sets the secret key used for the symmetric algorithm. (Overrides SymmetricAlgorithm.Key.)
Public propertySupported by Silverlight for Windows Phone KeySize Gets or sets the size, in bits, of the secret key used for the symmetric algorithm. (Overrides SymmetricAlgorithm.KeySize.)
Public propertySupported by Silverlight for Windows Phone LegalBlockSizes Gets the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public propertySupported by Silverlight for Windows Phone LegalKeySizes Gets the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)

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Methods

  Name Description
Public methodSupported by Silverlight for Windows Phone Clear Releases all resources used by the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm.)
Public methodSupported by Silverlight for Windows Phone CreateDecryptor() Creates a symmetric decryptor object using the current key and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateDecryptor().)
Public methodSupported by Silverlight for Windows Phone CreateDecryptor(array<Byte[], array<Byte[]) Creates a symmetric decryptor object using the specified key and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateDecryptor(array<Byte[], array<Byte[]).)
Public methodSupported by Silverlight for Windows Phone CreateEncryptor() Creates a symmetric encryptor object using the current key and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateEncryptor().)
Public methodSupported by Silverlight for Windows Phone CreateEncryptor(array<Byte[], array<Byte[]) Creates a symmetric encryptor object using the specified key and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateEncryptor(array<Byte[], array<Byte[]).)
Protected methodSupported by Silverlight for Windows Phone Dispose Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources. (Inherited from SymmetricAlgorithm.)
Public methodSupported by Silverlight for Windows Phone Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows Phone Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone GenerateIV Generates a random initialization vector (IV) to use for the symmetric algorithm. (Overrides SymmetricAlgorithm.GenerateIV().)
Public methodSupported by Silverlight for Windows Phone GenerateKey Generates a random key to use for the symmetric algorithm. (Overrides SymmetricAlgorithm.GenerateKey().)
Public methodSupported by Silverlight for Windows Phone GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone GetType Gets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows Phone MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone ToString Returns a string that represents the current object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone ValidKeySize Determines whether the specified key size is valid for the current algorithm. (Inherited from SymmetricAlgorithm.)

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Fields

  Name Description
Protected fieldSupported by Silverlight for Windows Phone BlockSizeValue Represents the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Protected fieldSupported by Silverlight for Windows Phone IVValue Represents the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected fieldSupported by Silverlight for Windows Phone KeySizeValue Represents the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected fieldSupported by Silverlight for Windows Phone KeyValue Represents the secret key for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected fieldSupported by Silverlight for Windows Phone LegalBlockSizesValue Specifies the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected fieldSupported by Silverlight for Windows Phone LegalKeySizesValue Specifies the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)

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Explicit Interface Implementations

  Name Description
Explicit interface implemetationPrivate methodSupported by Silverlight for Windows Phone IDisposable.Dispose Infrastructure. Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources. (Inherited from SymmetricAlgorithm.)

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Remarks

The AES algorithm is essentially the Rijndael symmetric algorithm with a fixed block size and iteration count. This class functions the same way as the .NET Framework RijndaelManaged class but limits blocks to 128 bits and does not allow feedback modes.

The cipher mode is always CBC, and the padding mode is always PKCS7.

Examples

The following example demonstrates how to encrypt and decrypt an isolated storage file by using the AesManaged class. To build and run this example, create a Silverlight-based application in Visual Studio named AesManaged and replace the MainPage.xaml file and the MainPage.xaml.cs (or MainPage.xaml.vb) file with the following code.

NoteNote:

If the XAML code is not displayed, click the Language Filter arrow at the top of this page, and select the XAML check box.

<UserControl x:Class="AESManaged.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="1024" Height="768">
    <Grid x:Name="LayoutRoot" Background="White" >
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="350" />
            <ColumnDefinition Width="250" />
            <!--<ColumnDefinition Width="250" />-->
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <TextBlock Grid.Row="0"  Grid.Column="0" FontSize="14" Text="Enter data to encrypt"/>
        <TextBlock Grid.Row="1" Grid.Column="0" FontSize="14" Text="Enter password and press Enter to encrypt" />
        <TextBlock Grid.Row="2" Grid.Column="0" FontSize="14" Text="Enter file to decrypt" />
        <TextBlock Grid.Row="3" Grid.Column="0" FontSize="14" Text="Enter password and press Enter to decrypt" />
        <TextBlock Grid.Row="4" Grid.Column="0" FontSize="14" Text="Enter file name to delete" />
        <TextBox x:Name="inputBox" Grid.Row="0" Grid.Column="1" TabIndex="0" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <PasswordBox x:Name="passwordBox" Grid.Row="1" Grid.Column="1" TabIndex ="1" FontSize="12"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBox x:Name="decryptBox" Grid.Row="2" Grid.Column="1" TabIndex="2" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <PasswordBox x:Name="decryptPassWordBox" Grid.Row="3" TabIndex="3" Grid.Column="1" FontSize="12" BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBox x:Name="deleteBox" Grid.Row="4" Grid.Column="1" TabIndex="4" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBlock x:Name="outputBlock" Grid.Row="5" Grid.Column="0" FontSize="12" TextWrapping="Wrap">
        </TextBlock>
    </Grid>
</UserControl>
<UserControl x:Class="AESManaged.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="1024" Height="768">
    <Grid x:Name="LayoutRoot" Background="White" >
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="350" />
            <ColumnDefinition Width="250" />
            <!--<ColumnDefinition Width="250" />-->
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <TextBlock Grid.Row="0"  Grid.Column="0" FontSize="14" Text="Enter data to encrypt"/>
        <TextBlock Grid.Row="1" Grid.Column="0" FontSize="14" Text="Enter password and press Enter to encrypt" />
        <TextBlock Grid.Row="2" Grid.Column="0" FontSize="14" Text="Enter file to decrypt" />
        <TextBlock Grid.Row="3" Grid.Column="0" FontSize="14" Text="Enter password and press Enter to decrypt" />
        <TextBlock Grid.Row="4" Grid.Column="0" FontSize="14" Text="Enter file name to delete" />
        <TextBox x:Name="inputBox" Grid.Row="0" Grid.Column="1" TabIndex="0" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <PasswordBox x:Name="passwordBox" Grid.Row="1" Grid.Column="1" TabIndex ="1" FontSize="12"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBox x:Name="decryptBox" Grid.Row="2" Grid.Column="1" TabIndex="2" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <PasswordBox x:Name="decryptPassWordBox" Grid.Row="3" TabIndex="3" Grid.Column="1" FontSize="12" BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBox x:Name="deleteBox" Grid.Row="4" Grid.Column="1" TabIndex="4" FontSize="12" IsReadOnly="False"  BorderThickness="5" Height="40"  Width="160" HorizontalAlignment="Center" />
        <TextBlock x:Name="outputBlock" Grid.Row="5" Grid.Column="0" FontSize="12" TextWrapping="Wrap">
        </TextBlock>
    </Grid>
</UserControl>
Imports System
Imports System.Windows.Controls
Imports System.Windows.Input
Imports System.IO
Imports System.IO.IsolatedStorage
Imports System.Security.Cryptography
Imports System.Security.Permissions
Imports System.Text



Namespace AESManaged
 Class MainPage
    Inherits UserControl
    Private Shared encryptedFiles As String = ""
    Private Shared store As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForSite()
    Private Const PasswordSalt As String = "PasswordSalt"
    Private Shared intSize As Integer = 4

    Public Sub New()
        InitializeComponent()
        AddHandler Me.inputBox.KeyDown, AddressOf inputBox_KeyDown
        AddHandler Me.passwordBox.KeyDown, AddressOf passwordBox_KeyDown
        AddHandler Me.decryptPassWordBox.KeyDown, AddressOf decryptPassWordBox_KeyDown
        AddHandler Me.deleteBox.KeyDown, AddressOf deleteBox_KeyDown

        store.CreateDirectory("MyFiles")

        ' Create subdirectory under MyFiles.
        encryptedFiles = System.IO.Path.Combine("MyFiles", "EncryptedFiles")

        store.CreateDirectory(encryptedFiles)
        ListFiles()
        inputBox.Focus()

    End Sub 'New 
    Private Sub inputBox_KeyDown(ByVal sender As Object, ByVal e As EventArgs)
        If CType(e, System.Windows.Input.KeyEventArgs).Key = Key.Enter Then
            Me.passwordBox.Focus()
        End If

    End Sub 'inputBox_KeyDown    
    Private Sub ListFiles()
        Dim searchpath As String = System.IO.Path.Combine(encryptedFiles, "*.*")
        Dim filesInSubDirs As String() = store.GetFileNames(searchpath)
        Dim sb As New StringBuilder()
        ' List files in MyFiles\EncryptedFiles.
        sb.AppendLine("Files in MyFiles\EncryptedFiles:")
        Dim fileName As String
        For Each fileName In filesInSubDirs
            sb.AppendLine(" - " + fileName)
        Next fileName
        sb.AppendLine()
        outputBlock.Text = sb.ToString()

    End Sub 'ListFiles   
    Private Sub deleteBox_KeyDown(ByVal sender As Object, ByVal e As EventArgs)

        If CType(e, System.Windows.Input.KeyEventArgs).Key = Key.Enter Then
            store.DeleteFile(encryptedFiles + "\" + deleteBox.Text)
            ListFiles()
            Me.passwordBox.Focus()
        End If

    End Sub 'deleteBox_KeyDown       
    Private Sub passwordBox_KeyDown(ByVal sender As Object, ByVal e As EventArgs)
        If CType(e, System.Windows.Input.KeyEventArgs).Key = Key.Enter Then
            Encrypt()
            Me.decryptBox.Focus()
        End If

    End Sub 'passwordBox_KeyDown     
    Private Sub decryptPassWordBox_KeyDown(ByVal sender As Object, ByVal e As EventArgs)
        If CType(e, System.Windows.Input.KeyEventArgs).Key = Key.Enter Then
            outputBlock.Text = Decrypt()
            Me.deleteBox.Focus()
        End If

    End Sub 'decryptPassWordBox_KeyDown   
    Private Function Decrypt() As String
        Dim store As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
        Dim encryptedFiles As String = System.IO.Path.Combine("MyFiles", "EncryptedFiles")
        store.CreateDirectory(encryptedFiles)
        Dim xFilePath As String = System.IO.Path.Combine(encryptedFiles, decryptBox.Text)

        Using isoStore As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
            Using isoStoreStream As IsolatedStorageFileStream = isoStore.OpenFile(xFilePath, FileMode.Open)
                Using aes = New System.Security.Cryptography.AesManaged()
                    Dim deriveBytes As New Rfc2898DeriveBytes(decryptPassWordBox.Password, Encoding.UTF8.GetBytes(PasswordSalt))
                    aes.Key = deriveBytes.GetBytes(128 / 8)
                    ' Get the initialization vector from the encrypted stream
                    aes.IV = ReadByteArray(isoStoreStream)
                    Dim cs As New CryptoStream(isoStoreStream, aes.CreateDecryptor(), CryptoStreamMode.Read)
                    Dim reader As New StreamReader(cs, Encoding.Unicode)
                    Try
                        Dim retval As String
                        retval = reader.ReadToEnd()
                        reader.Dispose()
                        cs.Dispose()
                        Return retval
                    Catch e As Exception
                        Return e.ToString()
                    End Try
                End Using
            End Using
        End Using


    End Function 'Decrypt    
    Private Sub Encrypt()
        Dim store As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
        Dim encryptedFiles As String = System.IO.Path.Combine("MyFiles", "EncryptedFiles")
        store.CreateDirectory(encryptedFiles)
        Dim xFilePath As String = System.IO.Path.Combine(encryptedFiles, "encryptedFile.txt")
        Dim xStream As IsolatedStorageFileStream = store.CreateFile(xFilePath)
        xStream.Close()
        decryptBox.Text = "encryptedFile.txt"
        Using isoStore As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
            Using isoStoreStream As IsolatedStorageFileStream = isoStore.OpenFile(xFilePath, FileMode.Create)
                Using aes = New System.Security.Cryptography.AesManaged()
                    Dim deriveBytes As New Rfc2898DeriveBytes(passwordBox.Password, Encoding.UTF8.GetBytes(PasswordSalt))
                    aes.Key = deriveBytes.GetBytes(128 / 8)
                    If Integer.MaxValue = Int64.MaxValue Then intSize = 8
                    isoStoreStream.Write(BitConverter.GetBytes(aes.IV.Length), 0, intSize)
                    isoStoreStream.Write(aes.IV, 0, aes.IV.Length)
                    Using cs As New CryptoStream(isoStoreStream, aes.CreateEncryptor(), CryptoStreamMode.Write)
                        Dim rawPlaintext As Byte() = Encoding.Unicode.GetBytes(inputBox.Text)
                        cs.Write(rawPlaintext, 0, rawPlaintext.Length)
                        cs.FlushFinalBlock()
                    End Using
                End Using
            End Using
        End Using
        xStream.Close()
        xStream = store.OpenFile(System.IO.Path.Combine(encryptedFiles, "encryptedFile.txt"), FileMode.Open)
        Dim reader As New StreamReader(xStream)
        ' Read the data.
        Me.outputBlock.Text = reader.ReadToEnd()
        reader.Close()
        xStream.Close()

    End Sub 'Encrypt    
    Private Shared Function ReadByteArray(ByVal s As Stream) As Byte()

        If Integer.MaxValue = Int64.MaxValue Then intSize = 8
        Dim rawLength(intSize - 1) As Byte
        If s.Read(rawLength, 0, rawLength.Length) <> rawLength.Length Then
            Throw New SystemException("Stream did not contain properly formatted byte array")
        End If

        Dim buffer(BitConverter.ToInt32(rawLength, 0) - 1) As Byte
        If s.Read(buffer, 0, buffer.Length) <> buffer.Length Then
            Throw New SystemException("Did not read byte array properly")
        End If

        Return buffer
    End Function 'ReadByteArray
 End Class 'Page
End Namespace
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.IO;
using System.IO.IsolatedStorage;
using System.Security.Cryptography;
using System.Security.Permissions;
using System.Text;
namespace AESManaged
{
    public partial class MainPage : UserControl
    {
        private static string encryptedFiles = "";
        private static IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForSite();
        private const string PasswordSalt = "PasswordSalt";
        public MainPage()
        {
            InitializeComponent();
            this.inputBox.KeyDown += new KeyEventHandler(inputBox_KeyDown);
            this.passwordBox.KeyDown += new KeyEventHandler(passwordBox_KeyDown);
            this.decryptPassWordBox.KeyDown += new KeyEventHandler(decryptPassWordBox_KeyDown);
            this.deleteBox.KeyDown += new KeyEventHandler(deleteBox_KeyDown);

            store.CreateDirectory("MyFiles");

            // Create subdirectory under MyFiles.
            encryptedFiles = System.IO.Path.Combine("MyFiles", "EncryptedFiles");

            store.CreateDirectory(encryptedFiles);
            ListFiles();
            inputBox.Focus();
        }
        private void inputBox_KeyDown(object sender, EventArgs e)
        {
            if (((System.Windows.Input.KeyEventArgs)e).Key == Key.Enter)
            {
                this.passwordBox.Focus();
            }
        }
        private void ListFiles()
        {
            string searchpath = System.IO.Path.Combine(encryptedFiles, "*.*");
            string[] filesInSubDirs = store.GetFileNames(searchpath);
            StringBuilder sb = new StringBuilder();
            // List files in MyFiles\EncryptedFiles.
            sb.AppendLine(@"Files in MyFiles\EncryptedFiles:");
            foreach (string fileName in filesInSubDirs)
            {
                sb.AppendLine(" - " + fileName);
            }
            sb.AppendLine();
            outputBlock.Text = sb.ToString();
        }
        private void deleteBox_KeyDown(object sender, EventArgs e)
        {

            if (((System.Windows.Input.KeyEventArgs)e).Key == Key.Enter)
            {
                store.DeleteFile(encryptedFiles + "\\" + deleteBox.Text);
                ListFiles();
                this.passwordBox.Focus();
            }
        }
        private void passwordBox_KeyDown(object sender, EventArgs e)
        {
            if (((System.Windows.Input.KeyEventArgs)e).Key == Key.Enter)
            {
                Encrypt();
                this.decryptBox.Focus();
            }

        }
        private void decryptPassWordBox_KeyDown(object sender, EventArgs e)
        {
            if (((System.Windows.Input.KeyEventArgs)e).Key == Key.Enter)
            {
                outputBlock.Text = Decrypt();
                this.deleteBox.Focus();
            }
        }
        private string Decrypt()
        {
            IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication();
            string encryptedFiles = System.IO.Path.Combine("MyFiles", "EncryptedFiles");
            store.CreateDirectory(encryptedFiles);
            string xFilePath = System.IO.Path.Combine(encryptedFiles, decryptBox.Text);

            using (IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication())
            using (IsolatedStorageFileStream isoStoreStream = isoStore.OpenFile(xFilePath, FileMode.Open))
            {
                using (Aes aes = new AesManaged())
                {
                    Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(decryptPassWordBox.Password, Encoding.UTF8.GetBytes(PasswordSalt));
                    aes.Key = deriveBytes.GetBytes(128 / 8);
                    // Get the initialization vector from the encrypted stream
                    aes.IV = ReadByteArray(isoStoreStream);
                    CryptoStream cs = new CryptoStream(isoStoreStream, aes.CreateDecryptor(), CryptoStreamMode.Read);
                    StreamReader reader = new StreamReader(cs, Encoding.Unicode);
                    try
                    {
                        string retval = reader.ReadToEnd();
                        reader.Dispose();
                        cs.Dispose();
                        return retval;
                    }
                    catch (Exception e)
                    {
                        return e.ToString();
                    }

                }
            }
        }
        private void Encrypt()
        {
            IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication();
            string encryptedFiles = System.IO.Path.Combine("MyFiles", "EncryptedFiles");
            store.CreateDirectory(encryptedFiles);
            string xFilePath = System.IO.Path.Combine(encryptedFiles, "encryptedFile.txt");
            IsolatedStorageFileStream xStream = store.CreateFile(xFilePath);
            xStream.Close();
            decryptBox.Text = "encryptedFile.txt";
            using (IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication())
            using (IsolatedStorageFileStream isoStoreStream = isoStore.OpenFile(xFilePath, FileMode.Create))
            {
                using (Aes aes = new AesManaged())
                {
                    Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(passwordBox.Password, Encoding.UTF8.GetBytes(PasswordSalt));
                    aes.Key = deriveBytes.GetBytes(128 / 8);
                    isoStoreStream.Write(BitConverter.GetBytes(aes.IV.Length), 0, sizeof(int));
                    isoStoreStream.Write(aes.IV, 0, aes.IV.Length);

                    using (CryptoStream cs = new CryptoStream(isoStoreStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
                    {
                        byte[] rawPlaintext = Encoding.Unicode.GetBytes(inputBox.Text);
                        cs.Write(rawPlaintext, 0, rawPlaintext.Length);
                        cs.FlushFinalBlock();
                    }
                }
            }
            xStream.Close();
            xStream =
                store.OpenFile(System.IO.Path.Combine(encryptedFiles, "encryptedFile.txt"), FileMode.Open);
            StreamReader reader = new StreamReader(xStream);
            // Read the data.
            this.outputBlock.Text = reader.ReadToEnd();
            reader.Close();
            xStream.Close();
        }
        private static byte[] ReadByteArray(Stream s)
        {
            byte[] rawLength = new byte[sizeof(int)];
            if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
            {
                throw new SystemException("Stream did not contain properly formatted byte array");
            }

            byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
            if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
            {
                throw new SystemException("Did not read byte array properly");
            }

            return buffer;
        }

    }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.