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




path
The location of the temporary files. This should be the same string that was used in the DicomNet constructor.
mode
The security mode to use when initializing the network structure. This should be the same value that was used in the DicomNet constructor.
openSslContextCreationSettings
A DicomOpenSslContextCreationSettings object that is used to modify the security defaults. This is used only if the parameter mode is DicomNetSecurityeMode.Tls. Pass a null reference (Nothing in Visual Basic) to get the default values.
Changes security options from the defaults.

Syntax

Visual Basic (Declaration) 
Public Sub Initialize( _
   ByVal path As String, _
   ByVal mode As DicomNetSecurityeMode, _
   ByVal openSslContextCreationSettings As DicomOpenSslContextCreationSettings _
) 
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim path As String
Dim mode As DicomNetSecurityeMode
Dim openSslContextCreationSettings As DicomOpenSslContextCreationSettings
 
instance.Initialize(path, mode, openSslContextCreationSettings)
Managed Extensions for C++ 
public: void Initialize( 
   string* path,
   DicomNetSecurityeMode mode,
   DicomOpenSslContextCreationSettings* openSslContextCreationSettings
) 

Parameters

path
The location of the temporary files. This should be the same string that was used in the DicomNet constructor.
mode
The security mode to use when initializing the network structure. This should be the same value that was used in the DicomNet constructor.
openSslContextCreationSettings
A DicomOpenSslContextCreationSettings object that is used to modify the security defaults. This is used only if the parameter mode is DicomNetSecurityeMode.Tls. Pass a null reference (Nothing in Visual Basic) to get the default values.

Example

This is a comprehensive sample that shows how to use DICOM Secure communication using TLS (with more control over the security settings).

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) connection with a client
'
Private Class ServerConnection : Inherits DicomNet

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.Tls, False)

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

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

    Protected Overrides Sub OnAccept(ByVal [error] As DicomExceptionCode)
       Dim serverPEM As String = "C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\server.pem"
       client = New ServerConnection()
       'Require and verify a client certificate.
       'Support SSL version 3 or TLS Version 1 for the handshake.
       'Use trusted certificate authority file to verify the client certificate
       'Verify the client certificate chain to a maximum depth of 2.
       Dim settings As New DicomOpenSslContextCreationSettings(DicomSslMethodType.TlsV1, _
          certificationAuthoritiesFileName, _
          DicomOpenSslVerificationFlags.Peer Or DicomOpenSslVerificationFlags.FailIfNoPeerCertificate, _
          2, _
          DicomOpenSslOptionsFlags.NoSslV2 Or DicomOpenSslOptionsFlags.AllBugWorkarounds)
       'You can use the properties too, to specify the context creation settings.
       settings.MethodType = DicomSslMethodType.SslV23
       settings.CertificationAuthoritiesFileName = certificationAuthoritiesFileName
       settings.VerificationFlags = DicomOpenSslVerificationFlags.Peer Or DicomOpenSslVerificationFlags.FailIfNoPeerCertificate
       settings.Options = DicomOpenSslOptionsFlags.NoSslV2 Or DicomOpenSslOptionsFlags.AllBugWorkarounds

       client.Initialize(Nothing, DicomNetSecurityeMode.Tls, settings)
       client.SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha)
       client.SetTlsClientCertificate(serverPEM, DicomTlsCertificateType.Pem, Nothing)

       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); 
    } 
 
    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) connection with a client 
// 
class ServerConnection : DicomNet 

    public ServerConnection() 
        : base(null, DicomNetSecurityeMode.Tls, false) 
    { 
 
    } 
 
    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) 
    { 
       string serverPEM = @"C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\server.pem"; 
       client = new ServerConnection(); 
       if (client != null) 
       { 
          string certificationAuthoritiesFileName = @"C:\Program Files\LEAD Technologies, Inc\LEADTOOLS 15\Images\CA.pem"; 
          //Require and verify a client certificate. 
          //Support SSL version 3 or TLS Version 1 for the handshake. 
          //Use trusted certificate authority file to verify the client certificate 
          //Verify the client certificate chain to a maximum depth of 2. 
          DicomOpenSslContextCreationSettings settings = new DicomOpenSslContextCreationSettings(DicomSslMethodType.TlsV1,  
             certificationAuthoritiesFileName, 
             DicomOpenSslVerificationFlags.Peer | 
             DicomOpenSslVerificationFlags.FailIfNoPeerCertificate, 
             2, 
             DicomOpenSslOptionsFlags.NoSslV2| 
             DicomOpenSslOptionsFlags.AllBugWorkarounds); 
          //You can use the properties too, to specify the context creation settings. 
          //settings.MethodType = DicomSslMethodType.SslV23; 
          //settings.CertificationAuthoritiesFileName = certificationAuthoritiesFileName; 
          //settings.VerificationFlags =  DicomOpenSslVerificationFlags.Peer | 
          //                              DicomOpenSslVerificationFlags.FailIfNoPeerCertificate; 
          //settings.Options = DicomOpenSslOptionsFlags.NoSslV2| DicomOpenSslOptionsFlags.AllBugWorkarounds; 
          client.Initialize(null, DicomNetSecurityeMode.Tls, settings); 
          client.SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha); 
          client.SetTlsClientCertificate(serverPEM, DicomTlsCertificateType.Pem, null); 
       } 
       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

This method is to be used in conjunction with the DicomNet(string, DicomNetSecurityeMode, bool) constructor when changing security options from the defaults. Note that when using the DicomNet(string, DicomNetSecurityeMode, bool) version of the constructor, in addition to calling Startup, it is also necessary to call Initialize in order to prepare the DicomNet object for use. Use the openSslContextCreationSettings parameter when the security mode is set to DicomNetSecurityeMode.Tls.

Note that the following uses of the DicomNet constructors are functionally equivalent:

  1. 
    DicomNet net = new DicomNet(path, mode);
    
  2. 
    DicomNet net = new DicomNet(path, mode, false);
    net.Initialize(path, mode, null);
    

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