DicomTlsCipherSuiteType Enumeration

Summary

Specifies the type of cipher suite used in the TLS security.

Syntax

C++

public enum DicomTlsCipherSuiteType

Public Enum DicomTlsCipherSuiteType

public enum class DicomTlsCipherSuiteType

Members

Value	Member	Description
0	None	No cipher suite has been agreed upon yet.
18	DheRsaWithDesCbcSha	(Deprecated do not use) TLS_RSA_WITH_DES_CBC_SHA
19	DheRsaWith3DesEdeCbcSha	(Deprecated do not use) TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
20	DheRsaAes256Sha	(Deprecated do not use) DHE_RSA_AES_256_SHA (SSL3)
21	RsaWithAes128CbcSha	TLS_RSA_WITH_AES_128_CBC_SHA (TLS 1.0)
22	RsaWith3DesEdeCbcSha	TLS_RSA_WITH_3DES_EDE_CBC_SHA (TLS 1.0)
23	DheRsaWithAes128GcmSha256	TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (TLS 1.2)
24	EcdheRsaWithAes128GcmSha256	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (TLS 1.2)
25	DheRsaWithAes256GcmSha384	TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (TLS 1.2)
26	EcdheRsaWithAes256GcmSha384	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (TLS 1.2)

Remarks

Currently, only the cipher suites listed are supported by LEADTOOLS.

Example

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

using Leadtools; 
using Leadtools.Dicom; 
 
 
[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); 
   } 
 
   public static void SetupTlsContext(DicomNet net, string certName) 
   { 
      string serverCA = Path.Combine(LEAD_VARS.ImagesDir, "ca.pem"); 
 
      if (net != null) 
      { 
         DicomOpenSslContextCreationSettings settings = new DicomOpenSslContextCreationSettings( 
            DicomSslMethodType.SslV23, 
            serverCA, 
            DicomOpenSslVerificationFlags.Peer | DicomOpenSslVerificationFlags.FailIfNoPeerCertificate, 
            2, 
            DicomOpenSslOptionsFlags.NoSslV2 | DicomOpenSslOptionsFlags.AllBugWorkarounds 
            ); 
         net.Initialize(null, DicomNetSecurityMode.Tls, settings); 
         net.SetTlsClientCertificate(certName, DicomTlsCertificateType.Pem, null); 
      } 
   } 
} 
 
//  
// Secure client (TLS)  
//  
class Client : DicomNet 
{ 
   AutoResetEvent waitEvent = new AutoResetEvent(false); 
   string clientPEM = Path.Combine(LEAD_VARS.ImagesDir, "client.pem"); 
 
   public Client() 
      : base(null, DicomNetSecurityMode.Tls) 
   { 
      SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWithDesCbcSha); 
      Utils.SetupTlsContext(this, clientPEM); 
   } 
 
   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 = Path.Combine(LEAD_VARS.ImagesDir, "server.pem"); 
 
   public ServerConnection() 
      : base(null, DicomNetSecurityMode.Tls) 
   { 
      SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha); 
      SetTlsClientCertificate(serverPEM, DicomTlsCertificateType.Pem, null); 
   } 
 
   protected override string OnPrivateKeyPassword(bool encryption) 
   { 
      return "test"; 
   } 
 
   // The OnVerify callback gets called twice, once for each certificate in the certificate chain. 
   protected override int OnVerify(int ok, string certificateString, DicomSecurityCertificateException ex) 
   { 
      string certificateMessageString = "Received Client Certificate:\n" + certificateString; 
 
      // Log that the SCP received the Client Certificate 
      Debug.WriteLine(certificateMessageString); 
 
      if (ex.Code != DicomSecurityCertificateExceptionCode.Success) 
      { 
         string message = string.Format("Error {0}: {1}", ex.Code, ex.Message); 
 
         // Log the error with Client Certificate 
         Debug.WriteLine(message); 
      } 
      return ok; 
   } 
} 
 
class Server : DicomNet 
{ 
   string serverPEM = Path.Combine(LEAD_VARS.ImagesDir, "server.pem"); 
 
   ServerConnection client; 
 
   public Server() 
      : base(null, DicomNetSecurityMode.Tls) 
   { 
      SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha); 
      Utils.SetupTlsContext(this, serverPEM); 
   } 
 
   protected override void OnAccept(DicomExceptionCode error) 
   { 
      client = new ServerConnection(); 
 
      Utils.SetupTlsContext(client, serverPEM); 
 
      Accept(client); 
   } 
 
   protected override string OnPrivateKeyPassword(bool encryption) 
   { 
      return "test"; 
   } 
 
   protected override void Dispose(bool __p1) 
   { 
      client.Dispose(); 
      base.Dispose(__p1); 
   } 
} 
 
public void TLSSecuritySample() 
{ 
   //Assert test to check file exists before running code 
   string clientPEM = Path.Combine(LEAD_VARS.ImagesDir, "ca.pem"); 
   Assert.IsTrue(File.Exists(clientPEM) == true, "Missing file: " + clientPEM); 
 
   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.  
 
         //Now we can get detailed information about the Cipher Suite   
         DicomTlsCipherSuiteType cipherSuite = client.GetTlsCipherSuite();// Can also call GetTlsCipherSuiteByIndex   
 
         Debug.WriteLine("Encryption Algorithm is : {0}", client.GetTlsEncryptionAlgorithm(cipherSuite)); 
         Debug.WriteLine("Authentication Algorithm is : {0}", client.GetTlsAuthenticationAlgorithm(cipherSuite)); 
         Debug.WriteLine("Integrity Algorithm is : {0}", client.GetTlsIntegrityAlgorithm(cipherSuite)); 
         Debug.WriteLine("Key Exchange Algorithm is : {0}", client.GetTlsKeyExchangeAlgorithm(cipherSuite)); 
         Debug.WriteLine("Encryption Key Length is : {0}", client.GetTlsEncryptionKeyLength(cipherSuite)); 
         Debug.WriteLine("Mutual Authentication Key Length is : {0}", client.GetTlsMutualAuthenticationKeyLength(cipherSuite)); 
 
         // Continue with normal dicom communication  
 
         client.CloseForced(true); 
      } 
      server.CloseForced(true); 
   } 
 
   DicomEngine.Shutdown(); 
   DicomNet.Shutdown(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Dicom 
 
<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 
 
   Public Shared Sub SetupTlsContext(ByVal net As DicomNet, ByVal certName As String) 
      Dim serverCA As String = Path.Combine(LEAD_VARS.ImagesDir, "ca.pem") 
 
      If net IsNot Nothing Then 
         Dim settings As New DicomOpenSslContextCreationSettings(DicomSslMethodType.SslV23, serverCA, DicomOpenSslVerificationFlags.Peer Or DicomOpenSslVerificationFlags.FailIfNoPeerCertificate, 2, DicomOpenSslOptionsFlags.NoSslV2 Or DicomOpenSslOptionsFlags.AllBugWorkarounds) 
         net.Initialize(Nothing, DicomNetSecurityMode.Tls, settings) 
         net.SetTlsClientCertificate(certName, DicomTlsCertificateType.Pem, Nothing) 
      End If 
   End Sub 
End Class 
 
'  
' Secure client (TLS)  
'  
Private Class Client : Inherits DicomNet 
   Private waitEvent As AutoResetEvent = New AutoResetEvent(False) 
   Private clientPEM As String = Path.Combine(LEAD_VARS.ImagesDir, "client.pem") 
 
   Public Sub New() 
      MyBase.New(Nothing, DicomNetSecurityMode.Tls) 
      SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWithDesCbcSha) 
      Utils.SetupTlsContext(Me, clientPEM) 
   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 = Path.Combine(LEAD_VARS.ImagesDir, "server.pem") 
 
   Public Sub New() 
      MyBase.New(Nothing, DicomNetSecurityMode.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 serverPEM As String = Path.Combine(LEAD_VARS.ImagesDir, "server.pem") 
 
   Private client As ServerConnection 
 
   Public Sub New() 
      MyBase.New(Nothing, DicomNetSecurityMode.Tls) 
      SetTlsCipherSuiteByIndex(0, DicomTlsCipherSuiteType.DheRsaWith3DesEdeCbcSha) 
      Utils.SetupTlsContext(Me, serverPEM) 
   End Sub 
 
   Protected Overrides Sub OnAccept(ByVal [error] As DicomExceptionCode) 
      client = New ServerConnection() 
 
      Utils.SetupTlsContext(client, serverPEM) 
 
      Accept(client) 
   End Sub 
 
   Protected Overrides Function OnPrivateKeyPassword(ByVal encryption As Boolean) As String 
      Return "test" 
   End Function 
 
   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.  
 
            'Now we can get detailed information about the Cipher Suite   
            Dim cipherSuite As DicomTlsCipherSuiteType = client.GetTlsCipherSuite() ' Can also call GetTlsCipherSuiteByIndex 
 
            Debug.WriteLine("Encryption Algorithm is : {0}", client.GetTlsEncryptionAlgorithm(cipherSuite)) 
            Debug.WriteLine("Authentication Algorithm is : {0}", client.GetTlsAuthenticationAlgorithm(cipherSuite)) 
            Debug.WriteLine("Integrity Algorithm is : {0}", client.GetTlsIntegrityAlgorithm(cipherSuite)) 
            Debug.WriteLine("Key Exchange Algorithm is : {0}", client.GetTlsKeyExchangeAlgorithm(cipherSuite)) 
            Debug.WriteLine("Encryption Key Length is : {0}", client.GetTlsEncryptionKeyLength(cipherSuite)) 
            Debug.WriteLine("Mutual Authentication Key Length is : {0}", client.GetTlsMutualAuthenticationKeyLength(cipherSuite)) 
 
            ' Continue with normal dicom communication  
 
            client.CloseForced(True) 
         End Using 
         server.CloseForced(True) 
      End Using 
 
      DicomEngine.Shutdown() 
      DicomNet.Shutdown() 
   End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class