SetIsclMaxCommunicationBlockLength Method

Summary

Sets the maximum communication block length that can be sent/received by the current entity.

Syntax

C++/CLI

public void SetIsclMaxCommunicationBlockLength( 
   int maxCommunicationBlockLength 
)

public: 
void SetIsclMaxCommunicationBlockLength(  
   int maxCommunicationBlockLength 
)

Parameters

maxCommunicationBlockLength
The maximum communication block length.

Remarks

An ISCL communication block contains a 32-bytes header, followed by data, if data is included. Please note that the size of the ISCL packets is 32 bytes larger than the communication block length, because of the header.

During mutual authentication, the client and server will agree to use the smaller communication block size of the two.

Failure of the method usually occurs if maxCommunicationBlockLength is too small for the maximum standard packet size (168 bytes).

Example

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 SetupISCL(DicomNet net, string authData) 
   { 
      net.SetIsclMutualAuthenticationAlgorithm(DicomIsclMutualAuthenticationMode.ThreePFourW); 
      net.SetIsclMutualAuthenticationKey(1, 11619789628100321); 
      net.SetIsclMutualAuthenticationKey(2, 34217865672122111); 
      net.SetIsclMutualAuthenticationKey(3, 1605935625518899689); 
      net.SetIsclMutualAuthenticationKey(4, 138217077775855676); 
      net.SetIsclMutualAuthenticationKey(5, 9117318694593010212); 
      net.SetIsclMutualAuthenticationKey(6, 3485297985488245687); 
      net.SetIsclMutualAuthenticationKey(7, 1533287511573403981); 
      net.SetIsclMutualAuthenticationKey(8, 5604839976916070822); 
      net.SetIsclIndexForMutualAuthentication(1); 
 
      net.SetIsclDefaultEncryptionMode(DicomIsclEncryptionMethodType.DesCbc); 
      net.SetIsclDefaultSigningMode(DicomIsclSigningMethodType.Md5); 
      net.SetIsclEncryptionKey(1, 8079278526052745737); 
      net.SetIsclEncryptionKey(2, 1312864321990916052); 
      net.SetIsclEncryptionKey(3, 7190959962252002117); 
      net.SetIsclEncryptionKey(4, 3619524191167482890); 
      net.SetIsclEncryptionKey(5, 3466658849848898336); 
      net.SetIsclEncryptionKey(6, 8474124475946342520); 
      net.SetIsclEncryptionKey(7, 7725464453540259890); 
      net.SetIsclEncryptionKey(8, 4320705344832296668); 
      net.SetIsclEncryptionKeyIndex(1); 
 
      net.SetIsclMaxMessageLength(1024000); 
      net.SetIsclMaxCommunicationBlockLength(8129); 
 
      byte[] data = new ASCIIEncoding().GetBytes(authData); 
 
      net.SetIsclAuthenticationData(data, data.GetLength(0)); 
   } 
} 
 
// 
// Secure client (ISCL) 
// 
public class Client : DicomNet 
{ 
   readonly AutoResetEvent waitEvent = new AutoResetEvent(false); 
 
   public Client() 
       : base(null, DicomNetSecurityMode.Iscl) 
   { 
      const string authData = "LEAD client ISCL"; 
 
      Utils.SetupISCL(this, authData); 
   } 
 
   public bool Wait() 
   { 
      WaitReturn ret = Utils.WaitForComplete((2 * 60) * 1000, waitEvent); 
 
      return (ret == WaitReturn.Complete); 
   } 
 
   protected override void OnConnect(DicomExceptionCode error) 
   { 
      waitEvent.Set(); 
   } 
 
   protected override void OnSecureLinkReady(DicomExceptionCode error) 
   { 
      Console.WriteLine("Iscl Peer Encryption is               : {0}", GetIsclPeerEncryption()); 
      Console.WriteLine("Iscl Peer Mac                         : {0}", GetIsclPeerMac()); 
      Console.WriteLine("Iscl Communication Block Length is    : {0}", GetIsclCommunicationBlockLength()); 
      Console.WriteLine("Iscl Index For Encryption             : {0}", GetIsclIndexForEncryption()); 
      Console.WriteLine("Is Iscl Queue Empty                   : {0}", IsIsclQueueEmpty()); 
      Console.WriteLine("Iscl Index For Mutual Authentication  : {0}", GetIsclIndexForMutualAuthentication()); 
      Console.WriteLine("Iscl Status is                        : {0}", GetIsclStatus()); 
      //We can also call  GetIsclPeerAuthenticationData() to Get the Peer Authentication Data 
      waitEvent.Set(); 
   } 
 
   protected override bool GetChallengeIscl(ref long challenge, long parameter) 
   { 
      challenge = 0x0123456789ABCDE1; 
      return true; 
   } 
 
   protected override bool InternalAuthenticateIscl(long challenge, ref long response, long parameter) 
   { 
      response = challenge + 1; 
      return true; 
   } 
 
   protected override bool ExternalAuthenticateIscl(long challenge, long response, long parameter) 
   { 
      if (response == (challenge + 1)) 
         return true; 
 
      return false; 
   } 
 
   protected override void OnReceiveAssociateAccept(DicomAssociate association) 
   { 
      waitEvent.Set(); 
   } 
 
   protected override void OnReceiveReleaseResponse() 
   { 
      waitEvent.Set(); 
   } 
 
   protected override void OnReceiveCEchoResponse(byte presentationID, int messageID, string affectedClass, DicomCommandStatusType status) 
   { 
      Debug.Assert(presentationID == 1, "Presentation id should be 1"); 
      Debug.Assert(messageID == 1, "Message ID should be 1"); 
      Debug.Assert(affectedClass == DicomUidType.VerificationClass, "Affected class should be " + DicomUidType.VerificationClass); 
      waitEvent.Set(); 
   } 
}; 
 
// 
// Secure server client (ISCL) 
// 
public class ServerConnection : DicomNet 
{ 
   public ServerConnection() 
       : base(null, DicomNetSecurityMode.Iscl) 
   { 
      const string authData = "LEAD ServerConnection ISCL"; 
      Utils.SetupISCL(this, authData); 
   } 
 
   protected override bool GetChallengeIscl(ref long challenge, long parameter) 
   { 
      challenge = 0x0123456789ABCDE1; 
      return true; 
   } 
 
   protected override bool InternalAuthenticateIscl(long challenge, ref long response, long parameter) 
   { 
      response = challenge + 1; 
      return true; 
   } 
 
   protected override bool ExternalAuthenticateIscl(long challenge, long response, long parameter) 
   { 
      if (response == challenge + 1) 
         return true; 
 
      return false; 
   } 
 
   protected override void OnReceiveAssociateRequest(DicomAssociate association) 
   { 
      DicomAssociate retAssociation = new DicomAssociate(false); 
 
      Debug.Assert(association.Called == "ServerTest", "Called AETitle should be ServerTest"); 
      Debug.Assert(association.Calling == "ClientTest", "Calling AETitle should be ClientTest"); 
      Debug.Assert(association.ImplementClass == "1.2.840.114257.1", "Implementation class should be 1.2.840.114257.1"); 
      Debug.Assert(association.ImplementationVersionName == "1", "Implementation version should be 1"); 
      Debug.Assert(association.MaxLength == 0x100000, "Max length should be 0x100000"); 
      Debug.Assert(association.GetAbstract(1) == DicomUidType.VerificationClass, "Presentation index 1 should be " + DicomUidType.VerificationClass); 
      Debug.Assert(association.GetTransfer(1, 0) == DicomUidType.ImplicitVRLittleEndian, "Abstract Syntax (1,0) should be " + DicomUidType.ImplicitVRLittleEndian); 
 
      // 
      // Build our Association Accept 
      // 
      retAssociation.Called = association.Called; 
      retAssociation.Calling = association.Calling; 
      retAssociation.ImplementClass = association.ImplementClass; 
      retAssociation.ImplementationVersionName = association.ImplementationVersionName; 
      for (int x = 0; x < association.PresentationContextCount; x++) 
      { 
         byte id = association.GetPresentationContextID(x); 
         string abSyntax = association.GetAbstract(id); 
         string trSyntax = DicomUidType.ImplicitVRLittleEndian; 
 
         retAssociation.AddPresentationContext(id, 0, abSyntax); 
         if (association.GetTransferCount(id) > 0) 
         { 
            trSyntax = association.GetTransfer(id, 0); 
         } 
 
         retAssociation.AddTransfer(id, trSyntax); 
      } 
      SendAssociateAccept(retAssociation); 
   } 
 
   protected override void OnReceiveReleaseRequest() 
   { 
      SendReleaseResponse(); 
   } 
 
   protected override void OnReceiveCEchoRequest(byte presentationID, int messageID, string affectedClass) 
   { 
      Debug.Assert(presentationID == 1, "Presentation id should be 1"); 
      Debug.Assert(messageID == 1, "Message ID should be 1"); 
      Debug.Assert(affectedClass == DicomUidType.VerificationClass, "Affected class should be " + DicomUidType.VerificationClass); 
 
      SendCEchoResponse(presentationID, messageID, DicomUidType.VerificationClass, DicomCommandStatusType.Success); 
   } 
}; 
 
public class Server : DicomNet 
{ 
   readonly AutoResetEvent waitEvent = new AutoResetEvent(false); 
 
   public Server() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   protected override void OnAccept(DicomExceptionCode error) 
   { 
      ServerConnection client = new ServerConnection(); 
 
      Accept(client); 
   } 
} 
 
public void ISCLSecuritySample() 
{ 
   DicomEngine.Startup(); 
   DicomNet.Startup(); 
 
   using (Server server = new Server()) 
   { 
      using (Client client = new Client()) 
      { 
         server.Listen("127.0.0.1", 106, 1); // start server 
         client.Connect("", 1006, "127.0.0.1", 106); // connect to secure 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"); 
         } 
 
         // If secure link is established you can now do your regular 
         // dicom communications. 
 
         // 
         // Send associate request 
         // 
         DicomAssociate associate = new DicomAssociate(true); 
 
         associate.Called = "ServerTest"; 
         associate.Calling = "ClientTest"; 
         associate.ImplementClass = "1.2.840.114257.1"; 
         associate.ImplementationVersionName = "1"; 
         associate.MaxLength = 0x100000; 
         associate.AddPresentationContext(1, 0, DicomUidType.VerificationClass); 
         associate.AddTransfer(1, DicomUidType.ImplicitVRLittleEndian); 
         client.SendAssociateRequest(associate); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendAssociateRequest timed out"); 
         } 
 
         // 
         // Send Echo Request 
         // 
         byte pid = client.Association.FindAbstract(DicomUidType.VerificationClass); 
 
         client.SendCEchoRequest(pid, 1, DicomUidType.VerificationClass); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendCEchoRequest timed out"); 
         } 
 
         // 
         // SendReleaseRequest 
         // 
         client.SendReleaseRequest(); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendReleaseRequest timed out"); 
         } 
 
         client.CloseForced(true); 
      } 
      server.CloseForced(true); 
   } 
 
   DicomEngine.Shutdown(); 
   DicomNet.Shutdown(); 
}