LDicomNet::Initialize

namespace LDicomNet_Initialize_Namespace 
{ 
 
#ifndef CA_CERT_NAME 
#define CA_CERT_NAME      MAKE_IMAGE_PATH(TEXT("CA.pem")) 
#endif 
 
#ifndef SERVER_CERT_NAME 
#define SERVER_CERT_NAME  MAKE_IMAGE_PATH(TEXT("Server.pem")) 
#endif 
 
#ifndef CLIENT_CERT_NAME 
#define CLIENT_CERT_NAME  MAKE_IMAGE_PATH(TEXT("Client.pem")) 
#endif 
 
   // Logs a message 
   // This implementation logs to the console, and the debug window 
   L_VOID LogMessage(TCHAR *szMsg) 
   { 
      wprintf(TEXT("\n")); 
      wprintf(szMsg); 
 
      OutputDebugStringW(TEXT("\n")); 
      OutputDebugStringW(szMsg); 
   } 
 
   L_VOID LogMessage(TCHAR *s, L_INT n) 
   { 
      TCHAR szLog[200] = {0}; 
      wsprintf(szLog, TEXT("%s [%d]"), s, n); 
      LogMessage(szLog); 
   } 
 
   L_INT PrivateKeyPassword(L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag) 
   { 
      UNREFERENCED_PARAMETER(nFlag); 
      LPCTSTR pszMyPassword= TEXT("test"); 
      L_INT nRet = 0; 
      if ((L_INT)_tcslen(pszMyPassword) < nSize) 
      { 
         _tcsncpy_s(pszPassword, nSize, pszMyPassword, nSize);  
         nRet = (L_INT)_tcslen(pszMyPassword); 
      } 
      return nRet; 
   } 
 
   L_VOID SetupTlsContext(LDicomNet *pNet, L_TCHAR *pszCertName) 
   { 
      if (pNet != NULL) 
      { 
         L_SSL_CTX_CREATE ctxCreate; 
         memset(&ctxCreate, 0, sizeof(L_SSL_CTX_CREATE)); 
         ctxCreate.uStructSize   = sizeof(L_SSL_CTX_CREATE); 
         ctxCreate.uFlags        = FLAG_SSL_CTX_CREATE_METHOD_TYPE | FLAG_SSL_CTX_CREATE_VERIFY_MODE |  
            FLAG_SSL_CTX_CREATE_VERIFY_DEPTH | FLAG_SSL_CTX_CREATE_OPTIONS | FLAG_SSL_CTX_CREATE_CAFILE; 
         ctxCreate.nMethodTypeSSL= TYPE_SSLV23_METHOD; 
         ctxCreate.pszCAfile     = CA_CERT_NAME; 
         ctxCreate.uVerifyMode   = L_SSL_VERIFY_PEER | L_SSL_VERIFY_FAIL_IF_NO_PEER_CERT; 
         ctxCreate.nVerifyDepth  = 2; 
         ctxCreate.nOptions      = L_SSL_OP_NO_SSLv2|L_SSL_OP_ALL; 
         ctxCreate.nReserved1    = 0; 
         ctxCreate.nReserved2    = 0; 
         L_INT nRet = pNet->Initialize(NULL, DICOM_SECURE_TLS, &ctxCreate); 
         if (nRet == DICOM_SUCCESS) 
         { 
            L_TCHAR szMsg[200] = {0}; 
            // Assign the server the certificate 
            // Note that SERVER_CERT_NAME contains both the password and an encrypted private key 
            // When loading the private key, the OnPrivateKeyPassword virtual function is called 
            // so that the encryption password "test" can be supplied 
            nRet = pNet->SetServerCertificateTLS (pszCertName, L_TLS_FILETYPE_PEM, NULL); 
            if (nRet == DICOM_SUCCESS) 
               wsprintf(szMsg, TEXT("%s loaded successfully"), pszCertName); 
            else 
               wsprintf(szMsg, TEXT("%s could not be loaded successfully -- error[%d]"), pszCertName, nRet); 
 
            LogMessage(szMsg); 
         } 
      } 
   } 
 
   L_VOID DumpTlsInformation(LDicomNet *pNet) 
   { 
      L_CIPHERSUITE ciphersuite; 
      ciphersuite = pNet->GetCiphersuiteTLS(); 
      switch(ciphersuite) 
      { 
      case TLS_DHE_RSA_WITH_DES_CBC_SHA: 
         LogMessage( TEXT("           Secure connected, cipher is TLS_DHE_RSA_WITH_DES_CBC_SHA")); 
         break; 
 
      case TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA: 
         LogMessage( TEXT("           Secure connected, cipher is TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA")); 
         break; 
 
      case TLS_DHE_RSA_AES256_SHA: 
         LogMessage( TEXT("           Secure connected, cipher is TLS_DHE_RSA_AES256_SHA")); 
         break; 
      } 
 
      L_UINT32 nEncryptionAlgorithm = pNet->GetEncryptionAlgorithmTLS(ciphersuite); 
      switch(nEncryptionAlgorithm) 
      { 
      case L_CRYPT_NONE: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_NONE")); 
         break; 
 
      case L_CRYPT_DES: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_DES")); 
         break; 
 
      case L_CRYPT_3DES: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_3DES")); 
         break; 
 
      case L_CRYPT_RC4: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_RC4")); 
         break; 
 
      case L_CRYPT_RC2: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_RC2")); 
         break; 
 
      case L_CRYPT_IDEA: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_IDEA")); 
         break; 
 
      case L_CRYPT_FORTEZZA: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_FORTEZZA")); 
         break; 
 
      case L_CRYPT_AES: 
         LogMessage(TEXT("           Encryption Algorithm: L_CRYPT_AES")); 
         break; 
      } 
 
      L_UINT32 auth = pNet->GetAuthenticationAlgorithmTLS(ciphersuite); 
      switch(auth) 
      { 
      case L_MUTUALAUTH_NONE: 
         LogMessage(TEXT("           Authentication Algorithm: L_MUTUALAUTH_NONE")); 
         break; 
 
      case L_MUTUALAUTH_RSA: 
         LogMessage(TEXT("           Authentication Algorithm: L_MUTUALAUTH_RSA")); 
         break; 
 
      case L_MUTUALAUTH_DSS: 
         LogMessage(TEXT("           Authentication Algorithm: L_MUTUALAUTH_DSS")); 
         break; 
 
      case L_MUTUALAUTH_DH:  
         LogMessage(TEXT("           Authentication Algorithm: L_MUTUALAUTH_DH")); 
         break; 
      } 
 
      L_UINT32 integrity = pNet->GetIntegrityAlgorithmTLS(ciphersuite); 
      switch(integrity) 
      { 
      case L_MAC_NONE: 
         LogMessage(TEXT("           Message Authentication code type: L_MAC_NONE")); 
         break; 
 
      case L_MAC_SHA1: 
         LogMessage(TEXT("           Message Authentication code type: L_MAC_SHA1")); 
         break; 
 
      case L_MAC_MD5: 
         LogMessage(TEXT("           Message Authentication code type: L_MAC_MD5")); 
         break; 
      } 
 
      L_UINT32 keyExchange = pNet->GetKeyExchangeAlgorithmTLS(ciphersuite); 
      switch(keyExchange) 
      { 
      case L_KEYEXCHANGE_NONE: 
         LogMessage(TEXT("           Key Exchange Algorithm: L_KEYEXCHANGE_NONE")); 
         break; 
 
      case L_KEYEXCHANGE_RSA_SIGNED_DHE: 
         LogMessage(TEXT("           Key Exchange Algorithm: L_KEYEXCHANGE_RSA_SIGNED_DHE")); 
         break; 
 
      case L_KEYEXCHANGE_RSA: 
         LogMessage(TEXT("           Key Exchange Algorithm: L_KEYEXCHANGE_RSA")); 
         break; 
 
      case L_KEYEXCHANGE_DH: 
         LogMessage(TEXT("           Key Exchange Algorithm: L_KEYEXCHANGE_DH")); 
         break; 
 
      case L_KEYEXCHANGE_DH_DSS: 
         LogMessage(TEXT("           Key  Exchange Algorithm: L_KEYEXCHANGE_DH_DSS")); 
         break; 
 
      case L_KEYEXCHANGE_FORTEZZA: 
         LogMessage(TEXT("           Key Exchange Algorithm: L_KEYEXCHANGE_FORTEZZA")); 
         break; 
      } 
 
      L_UINT32 uKeyLength = pNet->GetEncryptKeyLengthTLS(ciphersuite); 
      LogMessage(TEXT("           Encrypt Key Length"), uKeyLength); 
 
      L_UINT32 uMutualAuthKeyLength  = pNet->GetMutualAuthKeyLengthTLS(ciphersuite); 
      LogMessage(TEXT("           Mutual authentication key length"), uMutualAuthKeyLength); 
   } 
 
 
   // ******************************************************************************************* 
   // Client Class  
   // 
   // Class that is used to connect to the server  
   // ******************************************************************************************* 
   class CMyClient : public LDicomNet 
   { 
   public: 
      CMyClient(L_INT32 nMode): LDicomNet(NULL, nMode) 
      { 
         m_waitEvent = CreateEvent( NULL, TRUE, TRUE, TEXT("ClientEvent")); 
         ResetEvent(m_waitEvent); 
 
         this->SetCipherToIndexTLS(0, TLS_DHE_RSA_WITH_DES_CBC_SHA); 
 
         L_CIPHERSUITE ciphersuite; 
         ciphersuite = this->GetCipherFromIndexTLS(0); 
 
         assert(ciphersuite == TLS_DHE_RSA_WITH_DES_CBC_SHA); 
 
         this->SetClientCertificateTLS( MAKE_IMAGE_PATH(TEXT("Client.pem")), L_TLS_FILETYPE_PEM, NULL); 
      } 
 
      ~CMyClient(void) 
      { 
         CloseHandle(m_waitEvent); 
      } 
 
      // Client 
      L_VOID OnConnect                    (L_INT nError); 
      L_VOID OnSecureLinkReady            (L_UINT32 nError); 
      L_VOID OnReceiveAssociateAccept     (LDicomAssociate *pPDU); 
      L_VOID OnReceiveReleaseResponse     (); 
      L_VOID OnReceiveCEchoResponse       (L_UCHAR nPresentationID, L_UINT16 nMessageID, L_TCHAR *pszClass, L_UINT16 nStatus); 
      L_INT  OnPrivateKeyPassword         (L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag); 
      L_INT  OnVerify                     (L_INT ok, L_TCHAR *pszCertificateString, L_INT nError, L_TCHAR *pszErrorString); 
 
      L_BOOL Wait(DWORD timeout = 5000); 
 
   private: 
      HANDLE m_waitEvent; 
   }; 
 
   // Continues dispatching messages until hEvent is signaled, our timeout 
   // Returns TRUE if hEvent is signaled 
   // Returns FALSE if timeout 
   L_BOOL MessageLoop ( 
      HANDLE hEvent, // handles that need to be waited on 
      DWORD timeout  // timeout in milliseconds 
      ) 
   { 
      DWORD dwStart = GetTickCount(); 
      MSG msg = {0}; 
 
      volatile L_BOOL bRunForever = TRUE; 
      while (bRunForever) 
      { 
         if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))  
         { 
            TranslateMessage(&msg); 
            DispatchMessage(&msg); 
         } 
 
         if (WaitForSingleObject(hEvent, 0) == WAIT_OBJECT_0) 
         { 
            ResetEvent(hEvent); 
            return TRUE; 
         } 
 
         DWORD dwCurrent = GetTickCount(); 
         if ((dwCurrent - dwStart) > timeout) 
         { 
            return FALSE; 
         } 
      } 
      return TRUE; 
   } 
 
   L_VOID CMyClient::OnConnect(L_INT nError) 
   { 
      L_TCHAR szMsg[200] = {0}; 
 
      wsprintf(szMsg, TEXT("CMyClient::OnConnect: nError[%d]"), nError);  
      LogMessage(szMsg); 
   } 
 
   L_VOID CMyClient::OnSecureLinkReady(L_UINT32 nError) 
   { 
      UNREFERENCED_PARAMETER(nError); 
      SetEvent(m_waitEvent); 
      L_UINT32 uSecureMode = this->GetSecureMode(); 
      switch(uSecureMode) 
      { 
      case DICOM_SECURE_NONE: 
         LogMessage(TEXT("CMyClient::OnSecureLinkReady: DICOM_SECURE_NONE")); 
         break; 
      case DICOM_SECURE_ISCL: 
         LogMessage(TEXT("CMyClient::OnSecureLinkReady: DICOM_SECURE_ISCL")); 
         break; 
      case DICOM_SECURE_TLS: 
         { 
            LogMessage(TEXT("CMyClient::OnSecureLinkReady: DICOM_SECURE_TLS")); 
 
            if (nError == DICOM_SUCCESS) 
            { 
               DumpTlsInformation(this); 
            } 
            else 
            { 
               L_TCHAR szMsg[200] = {0}; 
               wsprintf(szMsg, TEXT(           "ClientTLS: Secure link error %d"), nError); 
               LogMessage(szMsg); 
            } 
         } 
         break; 
      } 
   } 
 
   L_VOID CMyClient::OnReceiveAssociateAccept  (LDicomAssociate *pPDU) 
   { 
      UNREFERENCED_PARAMETER(pPDU); 
      SetEvent(m_waitEvent); 
      LogMessage(TEXT("CMyClient::OnReceiveAssociateAccept")); 
   } 
    
   L_VOID CMyClient::OnReceiveCEchoResponse(L_UCHAR nPresentationID, L_UINT16 nMessageID, L_TCHAR *pszClass, L_UINT16 nStatus) 
   { 
      SetEvent(m_waitEvent); 
      L_TCHAR szMsg[200] = {0}; 
 
      if (pszClass == NULL) 
      { 
         pszClass = TEXT(""); 
      } 
      wsprintf(szMsg, TEXT("CMyClient::OnReceiveCEchoResponse: \n\tnPresentationID[%d], \n\tnMessageID[%d], \n\tpszClass[%s], \n\tnStatus[%d]"), nPresentationID, nMessageID, pszClass, nStatus);  
      LogMessage(szMsg); 
   } 
 
   L_INT CMyClient::OnPrivateKeyPassword(L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag) 
   { 
      return PrivateKeyPassword(pszPassword, nSize, nFlag); 
   } 
 
   L_INT CMyClient::OnVerify(L_INT ok, L_TCHAR *pszCertificateString, L_INT nError, L_TCHAR *pszErrorString) 
   { 
      L_TCHAR szMsg[200] = { 0 }; 
      wsprintf(szMsg, TEXT("CMyClient::OnVerify:  \n\tok[%d], \n\tnError[%d], \n\tpszErrorString[%s]"), ok, nError, pszErrorString); 
      LogMessage(szMsg); 
 
      LogMessage(TEXT("n\tpszCertificateString:\n\t")); 
      LogMessage(pszCertificateString); 
      return ok; 
   } 
 
   L_VOID CMyClient::OnReceiveReleaseResponse() 
   { 
      SetEvent(m_waitEvent); 
      LogMessage(TEXT("CMyClient::OnReceiveReleaseResponse")); 
   } 
 
   L_BOOL CMyClient::Wait(DWORD timeout) 
   { 
      L_BOOL bRet = MessageLoop(m_waitEvent,  timeout);   
      return bRet; 
   } 
 
   // ******************************************************************************************* 
   // Server Connection Class  
   // 
   // When a client connects, CMyServer creates a new instance of the CMyServerConnection class  
   // and accepts the connection.   
   // ******************************************************************************************* 
   class CMyServerConnection : public LDicomNet 
   { 
   public: 
      CMyServerConnection(L_INT32 nMode): LDicomNet(NULL, nMode) 
      { 
      } 
      ~CMyServerConnection(void) 
      { 
      } 
 
      // Server 
      L_VOID OnReceiveAssociateRequest    (LDicomAssociate *pPDU); 
      L_VOID OnReceiveAssociateReject     (L_UCHAR nResult, L_UCHAR nSource, L_UCHAR nReason); 
      L_VOID OnReceiveCEchoRequest        (L_UCHAR nPresentationID, L_UINT16 nMessageID, L_TCHAR *pszClass); 
      L_VOID OnReceiveReleaseRequest      (); 
      L_INT  OnPrivateKeyPassword         (L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag); 
   }; 
 
   #define SIZEINWORD(p) sizeof(p)/sizeof(L_TCHAR) 
   L_VOID CMyServerConnection::OnReceiveAssociateRequest(LDicomAssociate *pPDU) 
   { 
      LogMessage(TEXT("\tCMyServerConnection::OnReceiveAssociateRequest")); 
 
      //check the version, if not 1, reject it 
      if (pPDU->GetVersion() != 1) 
      { 
         LogMessage(TEXT("\tCMyServerConnection::SendAssociateReject")); 
         SendAssociateReject( 
            PDU_REJECT_RESULT_PERMANENT,  
            PDU_REJECT_SOURCE_USER,  
            PDU_REJECT_REASON_UNKNOWN 
            ); 
      } 
      else 
      {         
         LDicomAssociate DicomAssociate(FALSE); 
 
         L_TCHAR clientAE[20] = {0}; 
         pPDU->GetCalling(clientAE, 20); 
 
         if (lstrcmp(clientAE, TEXT("LEAD_CLIENT")) != 0) 
         { 
            LogMessage(TEXT("\tCMyServerConnection::SendAssociateReject")); 
            SendAssociateReject( 
               PDU_REJECT_RESULT_PERMANENT,  
               PDU_REJECT_SOURCE_USER,  
               PDU_REJECT_REASON_UNKNOWN 
               ); 
            return; 
         } 
 
         //Copy presentation objects from received 
         //Reply that we only support the first Transfer Syntax from the received hPDU 
         L_TCHAR szTransfer[PDU_MAX_UID_SIZE+1] = {0}; 
         L_TCHAR szAbstract[PDU_MAX_UID_SIZE+1] = {0}; 
         L_INT iPresentationCount = pPDU->GetPresentationCount(); 
         for (L_UCHAR i = 0; i<iPresentationCount; i++) 
         { 
            L_UCHAR nId = pPDU->GetPresentation(i); 
            pPDU->GetTransfer(nId, 0, szTransfer, PDU_MAX_UID_SIZE+1); 
            L_UCHAR nResult = PDU_ACCEPT_RESULT_SUCCESS; 
            pPDU->GetAbstract(nId, szAbstract, PDU_MAX_UID_SIZE+1); 
            DicomAssociate.AddPresentation( nId, nResult, szAbstract); 
            DicomAssociate.AddTransfer( nId, szTransfer); 
         } 
 
         LogMessage(TEXT("\tCMyServerConnection::SendAssociateAccept")); 
         SendAssociateAccept(&DicomAssociate); 
      } 
   } 
 
   L_VOID CMyServerConnection::OnReceiveAssociateReject(L_UCHAR nResult, L_UCHAR nSource, L_UCHAR nReason) 
   { 
      L_TCHAR szMsg[200] = {0}; 
      wsprintf(szMsg, TEXT("\tOnReceiveAssociateReject\nResult[%d]\nSource[%d]\nReason[%d]"), nResult, nSource, nReason); 
      LogMessage(szMsg); 
   } 
 
   L_VOID CMyServerConnection::OnReceiveCEchoRequest(L_UCHAR nPresentationID, L_UINT16 nMessageID, L_TCHAR *pszClass) 
   { 
      LogMessage(TEXT("\tCMyServerConnection::OnReceiveCEchoRequest")); 
 
      LogMessage(TEXT("\tCMyServerConnection::SendCEchoResponse")); 
      SendCEchoResponse(nPresentationID, nMessageID, pszClass, COMMAND_STATUS_SUCCESS); 
   } 
 
   L_VOID CMyServerConnection::OnReceiveReleaseRequest() 
   { 
      LogMessage(TEXT("\tCMyServerConnection::OnReceiveReleaseRequest")); 
      LogMessage(TEXT("\tCMyServerConnection::SendReleaseResponse")); 
      SendReleaseResponse(); 
   } 
 
   L_INT CMyServerConnection::OnPrivateKeyPassword(L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag) 
   { 
      return PrivateKeyPassword(pszPassword, nSize, nFlag); 
   } 
 
 
   // ******************************************************************************************* 
   // Server Class  
   // 
   // Listens for connections 
   // When a client connects, this class creates a CMyServerConnection and accepts the connection 
   // ******************************************************************************************* 
   class CMyServer : public LDicomNet 
   { 
   public: 
      CMyServer(L_INT32 nMode): LDicomNet(NULL, nMode) 
      { 
         m_pServerConnection = NULL; 
      } 
 
      ~CMyServer(void) 
      { 
         if (m_pServerConnection != NULL) 
         { 
            delete m_pServerConnection; 
         } 
      } 
 
      L_VOID OnAccept                     (L_INT nError); 
      L_VOID OnClose                      (L_INT nError, LDicomNet *pServerConnection); 
      L_INT  OnPrivateKeyPassword         (L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag); 
 
      CMyServerConnection *m_pServerConnection; 
   }; 
 
   L_VOID CMyServer::OnAccept(L_INT nError) 
   { 
      LogMessage(TEXT("\tCMyServer::OnAccept")); 
      if (nError != DICOM_SUCCESS) 
      { 
         return; 
      } 
 
      if (m_pServerConnection != NULL) 
      { 
         delete m_pServerConnection; 
         m_pServerConnection = NULL; 
      } 
 
      m_pServerConnection = new CMyServerConnection(DICOM_SECURE_TLS); 
      if (m_pServerConnection == NULL) 
      { 
         return; 
      } 
      SetupTlsContext(m_pServerConnection, SERVER_CERT_NAME); 
 
      nError = LDicomNet::Accept(m_pServerConnection); 
      if (nError != DICOM_SUCCESS) 
      { 
         delete m_pServerConnection; 
         return; 
      } 
   } 
 
   L_VOID CMyServer::OnClose(L_INT nError, LDicomNet *pServerConnection) 
   { 
      UNREFERENCED_PARAMETER(nError); 
      LogMessage(TEXT("\tCMyServer::OnClose")); 
      if (m_pServerConnection == pServerConnection) 
      { 
         m_pServerConnection = NULL; 
      } 
      delete (CMyServerConnection *)pServerConnection; 
   } 
 
   L_INT CMyServer::OnPrivateKeyPassword(L_TCHAR *pszPassword, L_INT nSize, L_INT nFlag) 
   { 
      return PrivateKeyPassword(pszPassword, nSize, nFlag); 
   } 
 
   // ******************************************************************************************* 
   // Sample starts here  
   // ******************************************************************************************* 
   #define WaitForProcessing() \ 
   { \ 
      if (!client.Wait()) \ 
      { \ 
         LogMessage(TEXT("Timeout: client.Connect")); \ 
         nRet = DICOM_ERROR_NET_TIME_OUT; \ 
         goto Cleanup; \ 
      } \ 
   }  
 
   L_INT LDicomNet_InitializeExample() 
   { 
      LogMessage(TEXT("\n\n *** Initialize ***")); 
 
      L_TCHAR *pszServerAddress = TEXT("127.0.0.1"); 
      L_UINT uServerPort = 105; 
      L_INT nRet = DICOM_SUCCESS; 
 
      LDicomNet::StartUp(); 
 
      CMyClient client(DICOM_SECURE_TLS); 
      CMyServer server(DICOM_SECURE_TLS); 
 
      SetupTlsContext(&client, CLIENT_CERT_NAME); 
      SetupTlsContext(&server, SERVER_CERT_NAME); 
      
      LogMessage(TEXT("\tCMyServer::Listen")); 
      nRet = server.Listen(pszServerAddress, uServerPort, 5); 
 
      LogMessage(TEXT("CMyClient::Connect")); 
      client.Connect(NULL, 0, pszServerAddress, uServerPort); 
      if (!client.Wait(2000)) 
      { 
         if (!client.IsConnected()) 
         { 
            LogMessage(TEXT("Timeout: client.Connect"));  
            nRet = DICOM_ERROR_NET_TIME_OUT; 
            goto Cleanup; 
         } 
      } 
 
      if (nRet == DICOM_SUCCESS) 
      { 
         //create the Associate Class as Request 
         LDicomAssociate dicomAssociateRequest(TRUE); 
         dicomAssociateRequest.Default(); 
 
         // Send A-Associate-RQ message 
         dicomAssociateRequest.SetCalled(TEXT("LEAD_SERVER")); 
         dicomAssociateRequest.SetCalling(TEXT("LEAD_CLIENT")); 
 
         LogMessage(TEXT("CMyClient::SendAssociateRequest")); 
         nRet = client.SendAssociateRequest(&dicomAssociateRequest); 
         if (!client.Wait(5000)) 
         { 
            LogMessage(TEXT("Timeout: client.Connect"));  
            nRet = DICOM_ERROR_NET_TIME_OUT; 
            goto Cleanup; 
         } 
      } 
 
      L_UCHAR nPresentationID = client.GetAssociate()->FindAbstract(UID_VERIFICATION_CLASS); 
      L_UINT16 uUniqueID = 99; 
 
      LogMessage(TEXT("CMyClient::SendCEchoRequest")); 
      client.SendCEchoRequest( nPresentationID, uUniqueID, UID_VERIFICATION_CLASS); 
      WaitForProcessing(); 
 
 
      LogMessage(TEXT("CMyClient::SendReleaseRequest")); 
      client.SendReleaseRequest(); 
      WaitForProcessing(); 
 
Cleanup: 
      LogMessage(TEXT("CMyClient::Close")); 
      client.Close(); 
      client.Wait(1000); 
 
      LogMessage(TEXT("\tCMyServer::Close")); 
      server.Close(); 
 
      LDicomNet::ShutDown(); 
 
      return nRet; 
   } 
 
}