Aes Aes Aes Aes Class

Definition

Represents the abstract base class from which all implementations of the Advanced Encryption Standard (AES) must inherit.

public ref class Aes abstract : System::Security::Cryptography::SymmetricAlgorithm
public abstract class Aes : System.Security.Cryptography.SymmetricAlgorithm
type Aes = class
    inherit SymmetricAlgorithm
Public MustInherit Class Aes
Inherits SymmetricAlgorithm
Inheritance
Derived

Examples

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

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

namespace Aes_Example
{
    class AesExample
    {
        public static void Main()
        {
            string original = "Here is some data to encrypt!";

            // Create a new instance of the Aes
            // class.  This generates a new key and initialization 
            // vector (IV).
            using (Aes myAes = Aes.Create())
            {

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

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

                //Display the original data and the decrypted data.
                Console.WriteLine("Original:   {0}", original);
                Console.WriteLine("Round Trip: {0}", roundtrip);
            }
        }
        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("IV");
            byte[] encrypted;
            
            // Create an Aes object
            // with the specified key and IV.
            using (Aes aesAlg = Aes.Create())
            {
                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.
                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_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 Aes object
            // with the specified key and IV.
            using (Aes aesAlg = Aes.Create())
            {
                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;

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



Class AesExample

    Public Shared Sub Main()
        Dim original As String = "Here is some data to encrypt!"

        ' Create a new instance of the Aes
        ' class.  This generates a new key and initialization 
        ' vector (IV).
        Using myAes As Aes = Aes.Create()
            ' Encrypt the string to an array of bytes.
            Dim encrypted As Byte() = EncryptStringToBytes_Aes(original, myAes.Key, myAes.IV)

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

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

    Shared 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("IV")
        End If
        Dim encrypted() As Byte
        
        ' Create an Aes object
        ' with the specified key and IV.
        Using aesAlg As Aes = Aes.Create()

            aesAlg.Key = Key
            aesAlg.IV = IV

            ' Create an encryptor to perform the stream transform.
            Dim encryptor As ICryptoTransform = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.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_Aes

    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 Aes object
        ' with the specified key and IV.
        Using aesAlg As Aes = Aes.Create()
            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 'AesExample

Constructors

Aes() Aes() Aes() Aes()

Initializes a new instance of the Aes class.

Properties

BlockSize BlockSize BlockSize BlockSize

Gets or sets the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSize FeedbackSize FeedbackSize FeedbackSize

Gets or sets the feedback size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
IV IV IV IV

Gets or sets the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Key Key Key Key

Gets or sets the secret key for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeySize KeySize KeySize KeySize

Gets or sets the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizes LegalBlockSizes LegalBlockSizes LegalBlockSizes
LegalKeySizes LegalKeySizes LegalKeySizes LegalKeySizes
Mode Mode Mode Mode

Gets or sets the mode for operation of the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
Padding Padding Padding Padding

Gets or sets the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Methods

Clear() Clear() Clear() Clear()

Releases all resources used by the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
Create() Create() Create() Create()

Creates a cryptographic object that is used to perform the symmetric algorithm.

Create(String) Create(String) Create(String) Create(String)

Creates a cryptographic object that specifies the implementation of AES to use to perform the symmetric algorithm.

CreateDecryptor() CreateDecryptor() CreateDecryptor() CreateDecryptor()

Creates a symmetric decryptor object with the current Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[]) CreateDecryptor(Byte[], Byte[])

When overridden in a derived class, creates a symmetric decryptor object with the specified Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateEncryptor() CreateEncryptor() CreateEncryptor() CreateEncryptor()

Creates a symmetric encryptor object with the current Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[]) CreateEncryptor(Byte[], Byte[])

When overridden in a derived class, creates a symmetric encryptor object with the specified Key property and initialization vector (IV).

(Inherited from SymmetricAlgorithm)
Dispose() Dispose() Dispose() Dispose()

Releases all resources used by the current instance of the SymmetricAlgorithm class.

(Inherited from SymmetricAlgorithm)
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.

(Inherited from SymmetricAlgorithm)
Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GenerateIV() GenerateIV() GenerateIV() GenerateIV()

When overridden in a derived class, generates a random initialization vector (IV) to use for the algorithm.

(Inherited from SymmetricAlgorithm)
GenerateKey() GenerateKey() GenerateKey() GenerateKey()

When overridden in a derived class, generates a random key (Key) to use for the algorithm.

(Inherited from SymmetricAlgorithm)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Returns a string that represents the current object.

(Inherited from Object)
ValidKeySize(Int32) ValidKeySize(Int32) ValidKeySize(Int32) ValidKeySize(Int32)

Determines whether the specified key size is valid for the current algorithm.

(Inherited from SymmetricAlgorithm)

Fields

BlockSizeValue BlockSizeValue BlockSizeValue BlockSizeValue

Represents the block size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
FeedbackSizeValue FeedbackSizeValue FeedbackSizeValue FeedbackSizeValue

Represents the feedback size, in bits, of the cryptographic operation.

(Inherited from SymmetricAlgorithm)
IVValue IVValue IVValue IVValue

Represents the initialization vector (IV) for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeySizeValue KeySizeValue KeySizeValue KeySizeValue

Represents the size, in bits, of the secret key used by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
KeyValue KeyValue KeyValue KeyValue

Represents the secret key for the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalBlockSizesValue LegalBlockSizesValue LegalBlockSizesValue LegalBlockSizesValue

Specifies the block sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
LegalKeySizesValue LegalKeySizesValue LegalKeySizesValue LegalKeySizesValue

Specifies the key sizes, in bits, that are supported by the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
ModeValue ModeValue ModeValue ModeValue

Represents the cipher mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)
PaddingValue PaddingValue PaddingValue PaddingValue

Represents the padding mode used in the symmetric algorithm.

(Inherited from SymmetricAlgorithm)

Explicit Interface Implementations

IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose()

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.

(Inherited from SymmetricAlgorithm)

Applies to