Aes Class

 
System_CAPS_noteNote

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

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


Public MustInherit Class Aes
	Inherits SymmetricAlgorithm

NameDescription
System_CAPS_protmethodAes()

Initializes a new instance of the Aes class.

NameDescription
System_CAPS_pubpropertyBlockSize

Gets or sets the block size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyFeedbackSize

Gets or sets the feedback size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyIV

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

System_CAPS_pubpropertyKey

Gets or sets the secret key for the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyKeySize

Gets or sets the size, in bits, of the secret key used by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyLegalBlockSizes

Gets the block sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyLegalKeySizes

Gets the key sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyMode

Gets or sets the mode for operation of the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyPadding

Gets or sets the padding mode used in the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

NameDescription
System_CAPS_pubmethodClear()

Releases all resources used by the SymmetricAlgorithm class.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodSystem_CAPS_staticCreate()

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

System_CAPS_pubmethodSystem_CAPS_staticCreate(String)

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

System_CAPS_pubmethodCreateDecryptor()

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

System_CAPS_pubmethodCreateDecryptor(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.)

System_CAPS_pubmethodCreateEncryptor()

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

System_CAPS_pubmethodCreateEncryptor(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.)

System_CAPS_pubmethodDispose()

Releases all resources used by the current instance of the SymmetricAlgorithm class.(Inherited from SymmetricAlgorithm.)

System_CAPS_protmethodDispose(Boolean)

Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGenerateIV()

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

System_CAPS_pubmethodGenerateKey()

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

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodValidKeySize(Int32)

Determines whether the specified key size is valid for the current algorithm.(Inherited from SymmetricAlgorithm.)

NameDescription
System_CAPS_protfieldBlockSizeValue

Represents the block size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldFeedbackSizeValue

Represents the feedback size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldIVValue

Represents the initialization vector (IV) for the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldKeySizeValue

Represents the size, in bits, of the secret key used by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldKeyValue

Represents the secret key for the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldLegalBlockSizesValue

Specifies the block sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldLegalKeySizesValue

Specifies the key sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldModeValue

Represents the cipher mode used in the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_protfieldPaddingValue

Represents the padding mode used in the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

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

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



Class AesExample

    Public Shared Sub Main()
        Try

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

    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 a decrytor 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 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
        End Using

        Return plaintext

    End Function 'DecryptStringFromBytes_Aes 
End Class 'AesExample

.NET Framework
Available since 3.5
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0

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

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