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RSAOAEPKeyExchangeDeformatter.DecryptKeyExchange Method

Extracts secret information from the encrypted key exchange data.

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

'Declaration
Public Overrides Function DecryptKeyExchange ( _
	rgbData As Byte() _
) As Byte()

Parameters

rgbData
Type: System.Byte()

The key exchange data within which the secret information is hidden.

Return Value

Type: System.Byte()
The secret information derived from the key exchange data.

ExceptionCondition
CryptographicException

The key exchange data verification has failed.

CryptographicUnexpectedOperationException

The key is missing.

You must specify a key before calling this method.

The following example shows how to use the DecryptKeyExchange method to recreate an exchange key from a message sender. This code example is part of a larger example provided for the RSAPKCS1KeyExchangeDeformatter class.

Public Sub Receive(ByVal iv() As Byte, ByVal encryptedSessionKey() As Byte, ByVal encryptedMessage() As Byte)

    Using aes = New AesCryptoServiceProvider()

        aes.IV = iv

        ' Decrypt the session key 
        Dim keyDeformatter As New RSAOAEPKeyExchangeDeformatter(rsaKey)
        aes.Key = keyDeformatter.DecryptKeyExchange(encryptedSessionKey)

        ' Decrypt the message 
        Using plaintext As New MemoryStream()
            Using cs As New CryptoStream(plaintext, aes.CreateDecryptor(), CryptoStreamMode.Write)
                    cs.Write(encryptedMessage, 0, encryptedMessage.Length)
                    cs.Close()

                    Dim message As String = Encoding.UTF8.GetString(plaintext.ToArray())
                    Console.WriteLine(message)
            End Using 
        End Using 
    End Using 

End Sub 'Receive

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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