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GetTlsEncryptionKeyLength Method
See Also  Example
Leadtools.Dicom Namespace > DicomNet Class : GetTlsEncryptionKeyLength Method




cipher
The cipher suite for which to get the length of the encryption key.
Returns the effective length, in bits, of the encryption key associated with the specified cipher suite (56 for DES, etc.).

Syntax

Visual Basic (Declaration) 
Public Function GetTlsEncryptionKeyLength( _
   ByVal cipher As DicomTlsCipherSuiteType _
) As Integer
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim cipher As DicomTlsCipherSuiteType
Dim value As Integer
 
value = instance.GetTlsEncryptionKeyLength(cipher)
C# 
public int GetTlsEncryptionKeyLength( 
   DicomTlsCipherSuiteType cipher
)
Managed Extensions for C++ 
public: int GetTlsEncryptionKeyLength( 
   DicomTlsCipherSuiteType cipher
)
C++/CLI 
public:
int GetTlsEncryptionKeyLength( 
   DicomTlsCipherSuiteType cipher
)

Parameters

cipher
The cipher suite for which to get the length of the encryption key.

Return Value

The effective length of the encryption key associated with the specified cipher suite.

Example

This is a comprehensive sample that shows how to use DICOM Secure communication using TLS.

Visual BasicCopy Code
<StructLayout(LayoutKind.Sequential)> _
Public Structure MSG
    Public hwnd As IntPtr
    Public message As UInteger
    Public wParam As IntPtr
    Public lParam As IntPtr
    Public time As UInteger
    Public p As System.Drawing.Point
End Structure
Public Enum WaitReturn
    Complete
    Timeout
End Enum

Private Class Utils
    <DllImport("user32.dll")> _
    Shared Function PeekMessage(<System.Runtime.InteropServices.Out()> ByRef lpMsg As MSG, ByVal hWnd As IntPtr, ByVal wMsgFilterMin As UInteger, ByVal wMsgFilterMax As UInteger, ByVal wRemoveMsg As UInteger) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    <DllImport("user32.dll")> _
    Shared Function TranslateMessage(ByRef lpMsg As MSG) As Boolean
    End Function
    <DllImport("user32.dll")> _
    Shared Function DispatchMessage(ByRef lpmsg As MSG) As IntPtr
    End Function

    Private Const PM_REMOVE As UInteger = 1

    Public Shared Function WaitForComplete(ByVal mill As Double, ByVal wh As WaitHandle) As WaitReturn
        Dim goal As TimeSpan = New TimeSpan(DateTime.Now.AddMilliseconds(mill).Ticks)

        Do
            Dim msg As MSG = New MSG()

            If PeekMessage(msg, IntPtr.Zero, 0, 0, PM_REMOVE) Then
                TranslateMessage(msg)
                DispatchMessage(msg)
            End If

            If wh.WaitOne(New TimeSpan(0, 0, 0), False) Then
                Return WaitReturn.Complete
            End If

            If goal.CompareTo(New TimeSpan(DateTime.Now.Ticks)) < 0 Then
                Return WaitReturn.Timeout
            End If

        Loop While True
    End Function
End Class

'
' Secure client (TLS)
'
Private Class Client : Inherits DicomNet
    Private waitEvent As AutoResetEvent = New AutoResetEvent(False)
    Private clientPEM As String = "C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\client.pem"

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.Tls)
        SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWithDesCbcSha)
        SetTlsClientCertificate(clientPEM, DicomTlsCertificateType.Pem, Nothing)

       'Over here we can get detailed information about the Cipher Suite
       ' Can also call GetTlsCipherSuiteByIndex
       Dim cipherSuite As DicomTlsCipherSuiteType
       cipherSuite = GetTlsCipherSuite()
       'Returns DicomTlsEncryptionMethodType
       Console.WriteLine("Encryption Algorithm is : {0}", GetTlsEncryptionAlgorithm(cipherSuite))
       'Returns DicomTlsAuthenticationMethodType
       Console.WriteLine("Authentication Algorithm is : {0}", GetTlsAuthenticationAlgorithm(cipherSuite))
       'Returns DicomTlsMacMethodType
       Console.WriteLine("Integrity Algorithm is : {0}", GetTlsIntegrityAlgorithm(cipherSuite))
       'Returns DicomTlsExchangeMethodType
       Console.WriteLine("Key Exchange Algorithm is : {0}", GetTlsKeyExchangeAlgorithm(cipherSuite))
       Console.WriteLine("Encryption Key Length is : {0}", GetTlsEncryptionKeyLength(cipherSuite))
       Console.WriteLine("Mutual Authentication Key Length is : {0}", GetTlsMutualAuthenticationKeyLength(cipherSuite))

    End Sub

    Public Function Wait() As Boolean
        Dim ret As WaitReturn

        ret = Utils.WaitForComplete((5 * 60) * 1000, waitEvent)

        Return (ret = WaitReturn.Complete)
    End Function

    Protected Overrides Sub OnConnect(ByVal [error] As DicomExceptionCode)
        waitEvent.Set()
    End Sub

    Protected Overrides Function OnPrivateKeyPassword(ByVal encryption As Boolean) As String
        Return "test"
    End Function

    Protected Overrides Sub OnSecureLinkReady(ByVal [error] As DicomExceptionCode)
        waitEvent.Set()
    End Sub
End Class

'
' Secure server (TLS)
'
Private Class ServerConnection : Inherits DicomNet

    Private serverPEM As String = "C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\server.pem"

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.Tls)
        SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha)
        SetTlsClientCertificate(serverPEM, DicomTlsCertificateType.Pem, Nothing)
    End Sub

    Protected Overrides Function OnPrivateKeyPassword(ByVal encryption As Boolean) As String
        Return "test"
    End Function
End Class

Private Class Server : Inherits DicomNet
    Private client As ServerConnection

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.None)
    End Sub

    Protected Overrides Sub OnAccept(ByVal [error] As DicomExceptionCode)
        client = New ServerConnection()

        Accept(client)
    End Sub

    Protected Overloads Overrides Sub Dispose(ByVal __p1 As Boolean)
        client.Dispose()
        MyBase.Dispose(__p1)
    End Sub
End Class



Public Sub TLSSecuritySample()
    DicomEngine.Startup()
    DicomNet.Startup()

    Using server As Server = New Server()
        Using client As Client = New Client()
            server.Listen("127.0.0.1", 104, 1) ' start server
            client.Connect(Nothing, 1000, "127.0.0.1", 104) ' connect to server
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("Connection timed out")
            End If

            Debug.Assert(client.IsConnected(), "Client not connected")

            '
            ' Wait for authenication
            '
            If (Not client.Wait()) Then
                Debug.Fail("Connection timed out waiting for authenication")
            End If

            ' Once two computers have negotiated the ciphersuite, and have
            ' authenticated each other, they can begin transferring
            ' messages and data between them.

            ' Continue with normal dicom communication

            client.CloseForced(True)
        End Using
        server.CloseForced(True)
    End Using

    DicomEngine.Shutdown()
    DicomNet.Shutdown()
End Sub
C#Copy Code
[StructLayout(LayoutKind.Sequential)] 
public struct MSG 
{ 
    public IntPtr hwnd; 
    public uint message; 
    public IntPtr wParam; 
    public IntPtr lParam; 
    public uint time; 
    public System.Drawing.Point p; 
} 
public enum WaitReturn 
{ 
    Complete, 
    Timeout, 
} 
 
class Utils 
{ 
    [DllImport("user32.dll")] 
    [return: MarshalAs(UnmanagedType.Bool)] 
    static extern bool PeekMessage(out MSG lpMsg, IntPtr hWnd, 
                                   uint wMsgFilterMin, uint wMsgFilterMax, 
                                   uint wRemoveMsg); 
 
    [DllImport("user32.dll")] 
    static extern bool TranslateMessage([In] ref MSG lpMsg); 
    [DllImport("user32.dll")] 
    static extern IntPtr DispatchMessage([In] ref MSG lpmsg); 
 
    const uint PM_REMOVE = 1; 
 
    public static WaitReturn WaitForComplete(double mill, WaitHandle wh) 
    { 
        TimeSpan goal = new TimeSpan(DateTime.Now.AddMilliseconds(mill).Ticks); 
 
        do 
        { 
            MSG msg = new MSG(); 
 
            if (PeekMessage(out msg, IntPtr.Zero, 0, 0, PM_REMOVE)) 
            { 
                TranslateMessage(ref msg); 
                DispatchMessage(ref msg); 
            } 
 
            if (wh.WaitOne(new TimeSpan(0, 0, 0), false)) 
            { 
                return WaitReturn.Complete; 
            } 
 
            if (goal.CompareTo(new TimeSpan(DateTime.Now.Ticks)) < 0) 
            { 
                return WaitReturn.Timeout; 
            } 
 
        } while (true); 
    } 
} 
 
// 
// Secure client (TLS) 
// 
class Client : DicomNet 
{ 
    AutoResetEvent waitEvent = new AutoResetEvent(false); 
    string clientPEM = @"C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\client.pem"; 
 
    public Client() 
        : base(null, DicomNetSecurityeMode.Tls) 
    { 
       SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWithDesCbcSha); 
       SetTlsClientCertificate(clientPEM,DicomTlsCertificateType.Pem, null); 
 
       //Over here we can get detailed information about the Cipher Suite 
       DicomTlsCipherSuiteType cipherSuite = GetTlsCipherSuite();// Can also call GetTlsCipherSuiteByIndex 
       //Returns DicomTlsEncryptionMethodType 
       Console.WriteLine("Encryption Algorithm is : {0}", GetTlsEncryptionAlgorithm(cipherSuite)); 
       //Returns DicomTlsAuthenticationMethodType 
       Console.WriteLine("Authentication Algorithm is : {0}", GetTlsAuthenticationAlgorithm(cipherSuite)); 
       //Returns DicomTlsMacMethodType 
       Console.WriteLine("Integrity Algorithm is : {0}", GetTlsIntegrityAlgorithm(cipherSuite)); 
       //Returns DicomTlsExchangeMethodType 
       Console.WriteLine("Key Exchange Algorithm is : {0}", GetTlsKeyExchangeAlgorithm(cipherSuite)); 
       Console.WriteLine("Encryption Key Length is : {0}", GetTlsEncryptionKeyLength(cipherSuite)); 
       Console.WriteLine("Mutual Authentication Key Length is : {0}", GetTlsMutualAuthenticationKeyLength(cipherSuite)); 
    } 
 
    public bool Wait() 
    { 
        WaitReturn ret; 
 
        ret = Utils.WaitForComplete((5 * 60) * 1000, waitEvent); 
 
        return (ret == WaitReturn.Complete); 
    } 
 
    protected override void OnConnect(DicomExceptionCode error) 
    { 
        waitEvent.Set(); 
    } 
 
    protected override string OnPrivateKeyPassword(bool encryption) 
    { 
        return "test"; 
    } 
 
    protected override void OnSecureLinkReady(DicomExceptionCode error) 
    { 
        waitEvent.Set(); 
    } 
} 
 
// 
// Secure server (TLS) 
// 
class ServerConnection : DicomNet 
{ 
 
    string serverPEM = @"C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\server.pem"; 
 
    public ServerConnection() 
        : base(null, DicomNetSecurityeMode.Tls) 
    { 
       SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha); 
       SetTlsClientCertificate(serverPEM, DicomTlsCertificateType.Pem, null); 
    } 
 
    protected override string OnPrivateKeyPassword(bool encryption) 
    { 
        return "test"; 
    } 
} 
 
class Server : DicomNet 
{ 
    ServerConnection client; 
 
    public Server() 
        : base(null, DicomNetSecurityeMode.None) 
    { 
    } 
 
    protected override void OnAccept(DicomExceptionCode error) 
    { 
        client = new ServerConnection(); 
 
        Accept(client); 
    } 
 
    protected override void Dispose(bool __p1) 
    { 
        client.Dispose(); 
        base.Dispose(__p1); 
    } 
} 
 
 
public void TLSSecuritySample() 
{ 
    DicomEngine.Startup(); 
    DicomNet.Startup(); 
 
    using (Server server = new Server()) 
    { 
        using (Client client = new Client()) 
        { 
            server.Listen("127.0.0.1", 104, 1); // start server 
            client.Connect(null, 1000, "127.0.0.1", 104); // connect to server 
            if (!client.Wait()) // wait for connection to finish 
            { 
                Debug.Fail("Connection timed out"); 
            } 
 
            Debug.Assert(client.IsConnected(), "Client not connected"); 
 
            // 
            // Wait for authenication 
            // 
            if (!client.Wait()) 
            { 
                Debug.Fail("Connection timed out waiting for authenication"); 
            } 
 
            // Once two computers have negotiated the ciphersuite, and have  
            // authenticated each other, they can begin transferring  
            // messages and data between them. 
 
            // Continue with normal dicom communication 
 
            client.CloseForced(true); 
        } 
        server.CloseForced(true); 
    } 
 
    DicomEngine.Shutdown(); 
    DicomNet.Shutdown(); 
}

Remarks

There are differences between the size of the key and the effective length. The security of a key is given by the effective length, not by the size (a DES key has 8 bytes, just like a DES40 key, but the first has 56 bits effective, and the second only 40).

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

Leadtools.Dicom requires a Medical toolkit license and unlock key. For more information, refer to: Raster Pro/Document/Medical Features