CryptoStream Constructor

Initializes a new instance of the CryptoStream class with a target data stream, the transformation to use, and the mode of the stream.

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

Public Sub New ( _
	stream As Stream, _
	transform As ICryptoTransform, _
	mode As CryptoStreamMode _


Type: System.IO.Stream
The stream on which to perform the cryptographic transformation.
Type: System.Security.Cryptography.ICryptoTransform
The cryptographic transformation that is to be performed on the stream.
Type: System.Security.Cryptography.CryptoStreamMode
One of the enumeration values that specifies whether to read or write the cryptographic stream.


stream is not readable.


stream is not writable.


stream is invalid.

Any object that derives from Stream can be passed into the stream parameter. Any object that implements ICryptoTransform (such as HashAlgorithm) can be passed into the transform parameter.

The following example demonstrates how to use the CryptoStream constructor when you encrypt an isolated storage file. This code example is part of a larger example provided for the AesManaged class.

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)
    End Using
End Using


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

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

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