Leadtools.Dicom Requires Medical product license | Send comments on this topic. | Back to Introduction - All Topics | Help Version 16.5.9.25
SetTlsCipherSuiteByIndex Method
See Also  Example
Leadtools.Dicom Namespace > DicomNet Class : SetTlsCipherSuiteByIndex Method



index
The position in an array for which to set the specified cipher suite. The cipher suites in this array are those known by the client and should be ordered by preference.
cipher
The cipher suite to set at the specified index. For a list of possible values, refer to the DicomTlsCipherSuiteType enumeration.
index
The position in an array for which to set the specified cipher suite. The cipher suites in this array are those known by the client and should be ordered by preference.
cipher
The cipher suite to set at the specified index. For a list of possible values, refer to the DicomTlsCipherSuiteType enumeration.
Sets the cipher suite for the specified index.

Syntax

Visual Basic (Declaration) 
Public Sub SetTlsCipherSuiteByIndex( _
   ByVal index As Integer, _
   ByVal cipher As DicomTlsCipherSuiteType _
)
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim index As Integer
Dim cipher As DicomTlsCipherSuiteType
 
instance.SetTlsCipherSuiteByIndex(index, cipher)
C# 
public void SetTlsCipherSuiteByIndex( 
   int index,
   DicomTlsCipherSuiteType cipher
)
C++/CLI 
public:
void SetTlsCipherSuiteByIndex( 
   int index,
   DicomTlsCipherSuiteType cipher
)

Parameters

index
The position in an array for which to set the specified cipher suite. The cipher suites in this array are those known by the client and should be ordered by preference.
cipher
The cipher suite to set at the specified index. For a list of possible values, refer to the DicomTlsCipherSuiteType enumeration.

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 = LeadtoolsExamples.Common.ImagesPath.Path + "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 = LeadtoolsExamples.Common.ImagesPath.Path + "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 = LeadtoolsExamples.Common.ImagesPath.Path + "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 = LeadtoolsExamples.Common.ImagesPath.Path + "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

The server chooses the first cipher suite proposed by the client, which it can understand. If the client puts the cipher suites with reduced security first, then a cipher suite with reduced security will most likely be selected by the server.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also

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