RijndaelManaged Class (System.Security.Cryptography)

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.NET Framework Class Library
RijndaelManaged Class

Accesses the managed version of the Rijndael algorithm. This class cannot be inherited.

Inheritance Hierarchy

System.Object
  System.Security.Cryptography.SymmetricAlgorithm
    System.Security.Cryptography.Rijndael
      System.Security.Cryptography.RijndaelManaged

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

Visual Basic
<ComVisibleAttribute(True)> _
Public NotInheritable Class RijndaelManaged _
	Inherits Rijndael
C#
[ComVisibleAttribute(true)]
public sealed class RijndaelManaged : Rijndael
Visual C++
[ComVisibleAttribute(true)]
public ref class RijndaelManaged sealed : public Rijndael
F#
[<Sealed>]
[<ComVisibleAttribute(true)>]
type RijndaelManaged =  
    class
        inherit Rijndael
    end

The RijndaelManaged type exposes the following members.

Constructors

  Name Description
Public method RijndaelManaged Initializes a new instance of the RijndaelManaged class.
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Properties

  Name Description
Public property BlockSize Gets or sets the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Public property FeedbackSize Gets or sets the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Public property IV Gets or sets the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property Key Gets or sets the secret key for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property KeySize Gets or sets the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property LegalBlockSizes Gets the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property LegalKeySizes Gets the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property Mode Gets or sets the mode for operation of the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Public property Padding Gets or sets the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
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Methods

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

  Name Description
Protected field BlockSizeValue Represents the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Protected field FeedbackSizeValue Represents the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.)
Protected field IVValue Represents the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field KeySizeValue Represents the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field KeyValue Represents the secret key for the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field LegalBlockSizesValue Specifies the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field LegalKeySizesValue Specifies the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field ModeValue Represents the cipher mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
Protected field PaddingValue Represents the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.)
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Remarks

This algorithm supports key lengths of 128, 192, or 256 bits.

Examples

The following example demonstrates how to encrypt and decrypt sample data using the RijndaelManaged class.

Visual Basic

Imports System
Imports System.IO
Imports System.Security.Cryptography



Class RijndaelExample

    Public Shared 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).
            Using myRijndael As New RijndaelManaged()

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

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

                'Display the original data and the decrypted data.
                Console.WriteLine("Original:   {0}", original)
                Console.WriteLine("Round Trip: {0}", roundtrip)
            End Using
        Catch e As Exception
            Console.WriteLine("Error: {0}", e.Message)
        End Try

    End Sub 'Main

    Shared Function EncryptStringToBytes(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
        Dim encrypted() As Byte
        ' Create an RijndaelManaged object
        ' with the specified key and IV.
        Using rijAlg As New RijndaelManaged()

            rijAlg.Key = Key
            rijAlg.IV = IV

            ' Create a decrytor to perform the stream transform.
            Dim encryptor As ICryptoTransform = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV)
            ' Create the streams used for encryption.
            Using msEncrypt As 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
                    encrypted = msEncrypt.ToArray()
                End Using
            End Using
        End Using

        ' Return the encrypted bytes from the memory stream.
        Return encrypted

    End Function 'EncryptStringToBytes

    Shared Function DecryptStringFromBytes(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 string used to hold
        ' the decrypted text.
        Dim plaintext As String = Nothing

        ' Create an RijndaelManaged object
        ' with the specified key and IV.
        Using rijAlg As New RijndaelManaged
            rijAlg.Key = Key
            rijAlg.IV = IV

            ' Create a decrytor to perform the stream transform.
            Dim decryptor As ICryptoTransform = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.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 
End Class


C#

using System;
using System.IO;
using System.Security.Cryptography;

namespace RijndaelManaged_Example
{
    class RijndaelExample
    {
        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).
                using (RijndaelManaged myRijndael = new RijndaelManaged())
                {
                    // Encrypt the string to an array of bytes.
                    byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV);

                    // Decrypt the bytes to a string.
                    string roundtrip = DecryptStringFromBytes(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(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");
            byte[] encrypted;
            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

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

                // Create the streams used for encryption.
                using (MemoryStream 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);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }


            // Return the encrypted bytes from the memory stream.
            return encrypted;

        }

        static string DecryptStringFromBytes(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 string used to hold
            // the decrypted text.
            string plaintext = null;

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

                // Create a decrytor to perform the stream transform.
                ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.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;

        }
    }
}


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("IV");

        // 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 an encryptor 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("IV");

        // 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;
}


Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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.
See Also

Reference

Other Resources