Como acessar um serviço WSE 3.0 com um cliente do WCF

Os clientes do Windows Communication Foundation (WCF) são compatíveis com o nível de conexão com Aprimoramentos de Serviços Web (WSE) 3.0 para serviços do Microsoft .NET quando os clientes do WCF são configurados para usar a versão de agosto de 2004 da especificação WS-Addressing. No entanto, os serviços WSE 3.0 não suportam o protocolo de troca de metadados (MEX), portanto, quando você usa a Ferramenta de utilitário de metadados ServiceModel (Svcutil.exe) para criar uma classe de cliente WCF, as configurações de segurança não são aplicadas a o cliente WCF gerado. Portanto, você deve especificar as configurações de segurança que o serviço WSE 3.0 exige após a geração do cliente WCF.

Você pode aplicar essas configurações de segurança usando uma associação personalizada para levar em conta os requisitos do serviço WSE 3.0 e os requisitos interoperáveis entre um serviço WSE 3.0 e um cliente WCF. Esses requisitos de interoperabilidade incluem o uso acima mencionado da especificação WS-Addressing de agosto de 2004 e a proteção de mensagem padrão WSE 3.0 de SignBeforeEncrypt. A proteção de mensagem padrão para WCF é SignBeforeEncryptAndEncryptSignature. Este tópico detalha como criar uma associação WCF que interopera com um serviço WSE 3.0. O WCF também fornece um exemplo que incorpora essa associação. Para obter mais informações sobre este exemplo, consulte Interoperando com ASMX Web Services.

Para acessar um serviço da Web WSE 3.0 com um cliente WCF

  1. Execute a Ferramenta de utilitário de metadados ServiceModel (Svcutil.exe) para criar um cliente WCF para o serviço Web WSE 3.0.

    Para um serviço Web WSE 3.0, um cliente WCF é criado. Como o WSE 3.0 não oferece suporte ao protocolo MEX, você não pode usar a ferramenta para recuperar os requisitos de segurança do serviço Web. O desenvolvedor do aplicativo deve adicionar as configurações de segurança para o cliente.

    Para obter mais informações sobre como criar um cliente WCF, consulte Como: criar um cliente.

  2. Crie uma classe que represente uma associação que possa se comunicar com os serviços da Web WSE 3.0.

    A classe a seguir faz parte do exemplo interoperação com o WSE:

    1. Crie uma classe que derive da classe Binding.

      O exemplo de código a seguir cria uma classe chamada WseHttpBinding que deriva da classe Binding.

      public class WseHttpBinding : Binding
      {
      
      Public Class WseHttpBinding
          Inherits Binding
      
    2. Adicione propriedades à classe que especificam a declaração pronta para uso do WSE usada pelo serviço WSE, se as chaves derivadas são necessárias, se as sessões seguras são usadas, se as confirmações de assinatura são necessárias e as configurações de proteção de mensagem. No WSE 3.0, uma declaração pronta para uso especifica os requisitos de segurança para um cliente ou serviço da Web — semelhante ao modo de autenticação de uma associação no WCF.

      O exemplo de código a seguir define as propriedades SecurityAssertion, RequireDerivedKeys, EstablishSecurityContext e MessageProtectionOrder que especificam a declaração pronta para uso do WSE, se as chaves derivadas são necessárias, se as sessões seguras são usadas, se as confirmações de assinatura são necessárias e o configurações de proteção de mensagens, respectivamente.

      
      private WseSecurityAssertion assertion;
      public WseSecurityAssertion SecurityAssertion
      {
          get { return assertion; }
          set { assertion = value; }
      }
      
      private bool requireDerivedKeys;
      public bool RequireDerivedKeys
      {
          get { return requireDerivedKeys; }
          set { requireDerivedKeys = value; }
      }
      
      private bool establishSecurityContext;
      public bool EstablishSecurityContext
      {
          get { return establishSecurityContext; }
          set { establishSecurityContext = value; }
      }
      
      private bool requireSignatureConfirmation;
      public bool RequireSignatureConfirmation
      {
          get { return requireSignatureConfirmation; }
          set { requireSignatureConfirmation = value; }
      }
      
      private MessageProtectionOrder messageProtectionOrder;
      public MessageProtectionOrder MessageProtectionOrder
      {
          get { return messageProtectionOrder; }
          set { messageProtectionOrder = value; }
      }
      
      Public Property SecurityAssertion() As WseSecurityAssertion
      
          Get
      
              Return assertion
      
          End Get
          Set(ByVal value As WseSecurityAssertion)
      
              assertion = value
      
          End Set
      
      End Property
      
      Private m_requireDerivedKeys As Boolean
      Public Property RequireDerivedKeys() As Boolean
      
          Get
      
              Return m_requireDerivedKeys
      
          End Get
          Set(ByVal value As Boolean)
      
              m_requireDerivedKeys = value
      
          End Set
      
      End Property
      
      Private m_establishSecurityContext As Boolean
      Public Property EstablishSecurityContext() As Boolean
      
          Get
      
              Return m_establishSecurityContext
      
          End Get
          Set(ByVal value As Boolean)
      
              m_establishSecurityContext = value
      
          End Set
      
      End Property
      
      Private m_requireSignatureConfirmation As Boolean
      Public Property RequireSignatureConfirmation() As Boolean
      
          Get
      
              Return m_requireSignatureConfirmation
      
          End Get
          Set(ByVal value As Boolean)
      
              m_requireSignatureConfirmation = value
      
          End Set
      
      End Property
      
      Private m_messageProtectionOrder As MessageProtectionOrder
      Public Property MessageProtectionOrder() As MessageProtectionOrder
      
          Get
      
              Return m_messageProtectionOrder
      
          End Get
          Set(ByVal value As MessageProtectionOrder)
      
              m_messageProtectionOrder = value
      
          End Set
      
      End Property
      
    3. Substitua o método CreateBindingElements para definir as propriedades de associação.

      O exemplo de código a seguir especifica as configurações de transporte, codificação de mensagem e proteção de mensagem obtendo os valores das propriedades SecurityAssertion e MessageProtectionOrder.

      public override BindingElementCollection CreateBindingElements()
      {
          //SecurityBindingElement sbe = bec.Find<SecurityBindingElement>();
          BindingElementCollection bec = new BindingElementCollection();
          // By default http transport is used
          SecurityBindingElement securityBinding;
          BindingElement transport;
      
          switch (assertion)
          {
              case WseSecurityAssertion.UsernameOverTransport:
                  transport = new HttpsTransportBindingElement();
                  securityBinding = (TransportSecurityBindingElement)SecurityBindingElement.CreateUserNameOverTransportBindingElement();
                  if (establishSecurityContext == true)
                      throw new InvalidOperationException("Secure Conversation is not supported for this Security Assertion Type");
                  if (requireSignatureConfirmation == true)
                      throw new InvalidOperationException("Signature Confirmation is not supported for this Security Assertion Type");
                  break;
              case WseSecurityAssertion.MutualCertificate10:
                  transport = new HttpTransportBindingElement();
                  securityBinding = SecurityBindingElement.CreateMutualCertificateBindingElement(MessageSecurityVersion.WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10);
                  if (requireSignatureConfirmation == true)
                      throw new InvalidOperationException("Signature Confirmation is not supported for this Security Assertion Type");
                  ((AsymmetricSecurityBindingElement)securityBinding).MessageProtectionOrder = messageProtectionOrder;
                  break;
              case WseSecurityAssertion.UsernameForCertificate:
                  transport = new HttpTransportBindingElement();
                  securityBinding = (SymmetricSecurityBindingElement)SecurityBindingElement.CreateUserNameForCertificateBindingElement();
                  // We want signatureconfirmation on the bootstrap process
                  // either for the application messages or for the RST/RSTR
                  ((SymmetricSecurityBindingElement)securityBinding).RequireSignatureConfirmation = requireSignatureConfirmation;
                  ((SymmetricSecurityBindingElement)securityBinding).MessageProtectionOrder = messageProtectionOrder;
                  break;
              case WseSecurityAssertion.AnonymousForCertificate:
                  transport = new HttpTransportBindingElement();
                  securityBinding = (SymmetricSecurityBindingElement)SecurityBindingElement.CreateAnonymousForCertificateBindingElement();
                  ((SymmetricSecurityBindingElement)securityBinding).RequireSignatureConfirmation = requireSignatureConfirmation;
                  ((SymmetricSecurityBindingElement)securityBinding).MessageProtectionOrder = messageProtectionOrder;
                  break;
              case WseSecurityAssertion.MutualCertificate11:
                  transport = new HttpTransportBindingElement();
                  securityBinding = SecurityBindingElement.CreateMutualCertificateBindingElement(MessageSecurityVersion.WSSecurity11WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11);
                  ((SymmetricSecurityBindingElement)securityBinding).RequireSignatureConfirmation = requireSignatureConfirmation;
                  ((SymmetricSecurityBindingElement)securityBinding).MessageProtectionOrder = messageProtectionOrder;
                  break;
              case WseSecurityAssertion.Kerberos:
                  transport = new HttpTransportBindingElement();
                  securityBinding = (SymmetricSecurityBindingElement)SecurityBindingElement.CreateKerberosBindingElement();
                  ((SymmetricSecurityBindingElement)securityBinding).RequireSignatureConfirmation = requireSignatureConfirmation;
                  ((SymmetricSecurityBindingElement)securityBinding).MessageProtectionOrder = messageProtectionOrder;
                  break;
              default:
                  throw new NotSupportedException("This supplied Wse security assertion is not supported");
          }
          //Set defaults for the security binding
          securityBinding.IncludeTimestamp = true;
      
          // Derived Keys
          // set the preference for derived keys before creating SecureConversationBindingElement
          securityBinding.SetKeyDerivation(requireDerivedKeys);
      
          //Secure Conversation
          if (establishSecurityContext == true)
          {
              SymmetricSecurityBindingElement secureconversation =
                      (SymmetricSecurityBindingElement)SymmetricSecurityBindingElement.CreateSecureConversationBindingElement(
                                                  securityBinding, false);
              // This is the default
              //secureconversation.DefaultProtectionLevel = ProtectionLevel.EncryptAndSign;
      
              //Set defaults for the secure conversation binding
              secureconversation.DefaultAlgorithmSuite = SecurityAlgorithmSuite.Basic256;
              // We do not want signature confirmation on the application level messages
              // when secure conversation is enabled.
              secureconversation.RequireSignatureConfirmation = false;
              secureconversation.MessageProtectionOrder = messageProtectionOrder;
              secureconversation.SetKeyDerivation(requireDerivedKeys);
              securityBinding = secureconversation;
          }
      
          // Add the security binding to the binding collection
          bec.Add(securityBinding);
      
          // Add the message encoder.
          TextMessageEncodingBindingElement textelement = new TextMessageEncodingBindingElement();
          textelement.MessageVersion = MessageVersion.Soap11WSAddressingAugust2004;
          //These are the defaults required for WSE
          //textelement.MessageVersion = MessageVersion.Soap11Addressing1;
          //textelement.WriteEncoding = System.Text.Encoding.UTF8;
          bec.Add(textelement);
      
          // Add the transport
          bec.Add(transport);
      
          // return the binding elements
          return bec;
      }
      
      Public Overloads Overrides Function CreateBindingElements() As BindingElementCollection
      
          'SecurityBindingElement sbe = bec.Find<SecurityBindingElement>();
          Dim bec As New BindingElementCollection()
          ' By default http transport is used
          Dim securityBinding As SecurityBindingElement
          Dim transport As BindingElement
      
          Select Case assertion
      
              Case WseSecurityAssertion.UsernameOverTransport
                  transport = New HttpsTransportBindingElement()
                  securityBinding = DirectCast(SecurityBindingElement.CreateUserNameOverTransportBindingElement(), TransportSecurityBindingElement)
                  If m_establishSecurityContext = True Then
                      Throw New InvalidOperationException("Secure Conversation is not supported for this Security Assertion Type")
                  End If
                  If m_requireSignatureConfirmation = True Then
                      Throw New InvalidOperationException("Signature Confirmation is not supported for this Security Assertion Type")
                  End If
                  Exit Select
              Case WseSecurityAssertion.MutualCertificate10
                  transport = New HttpTransportBindingElement()
                  securityBinding = SecurityBindingElement.CreateMutualCertificateBindingElement(MessageSecurityVersion.WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10)
                  If m_requireSignatureConfirmation = True Then
                      Throw New InvalidOperationException("Signature Confirmation is not supported for this Security Assertion Type")
                  End If
                  DirectCast(securityBinding, AsymmetricSecurityBindingElement).MessageProtectionOrder = m_messageProtectionOrder
                  Exit Select
              Case WseSecurityAssertion.UsernameForCertificate
                  transport = New HttpTransportBindingElement()
                  securityBinding = DirectCast(SecurityBindingElement.CreateUserNameForCertificateBindingElement(), SymmetricSecurityBindingElement)
                  ' We want signatureconfirmation on the bootstrap process
                  ' either for the application messages or for the RST/RSTR
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).RequireSignatureConfirmation = m_requireSignatureConfirmation
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).MessageProtectionOrder = m_messageProtectionOrder
                  Exit Select
              Case WseSecurityAssertion.AnonymousForCertificate
                  transport = New HttpTransportBindingElement()
                  securityBinding = DirectCast(SecurityBindingElement.CreateAnonymousForCertificateBindingElement(), SymmetricSecurityBindingElement)
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).RequireSignatureConfirmation = m_requireSignatureConfirmation
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).MessageProtectionOrder = m_messageProtectionOrder
                  Exit Select
              Case WseSecurityAssertion.MutualCertificate11
                  transport = New HttpTransportBindingElement()
                  securityBinding = SecurityBindingElement.CreateMutualCertificateBindingElement(MessageSecurityVersion.WSSecurity11WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11)
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).RequireSignatureConfirmation = m_requireSignatureConfirmation
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).MessageProtectionOrder = m_messageProtectionOrder
                  Exit Select
              Case WseSecurityAssertion.Kerberos
                  transport = New HttpTransportBindingElement()
                  securityBinding = DirectCast(SecurityBindingElement.CreateKerberosBindingElement(), SymmetricSecurityBindingElement)
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).RequireSignatureConfirmation = m_requireSignatureConfirmation
                  DirectCast(securityBinding, SymmetricSecurityBindingElement).MessageProtectionOrder = m_messageProtectionOrder
                  Exit Select
              Case Else
                  Throw New NotSupportedException("This supplied Wse security assertion is not supported")
      
          End Select
      
          'Set defaults for the security binding
          securityBinding.IncludeTimestamp = True
      
          ' Derived Keys
          ' Set the preference for derived keys before creating the binding for SecureConversation.
          securityBinding.SetKeyDerivation(m_requireDerivedKeys)
      
          'Secure Conversation
          If m_establishSecurityContext = True Then
      
              Dim secureconversation As SymmetricSecurityBindingElement = DirectCast(SymmetricSecurityBindingElement.CreateSecureConversationBindingElement(securityBinding, False), SymmetricSecurityBindingElement)
              ' This is the default
              'secureconversation.DefaultProtectionLevel = ProtectionLevel.EncryptAndSign;
      
              'Set defaults for the secure conversation binding
              secureconversation.DefaultAlgorithmSuite = SecurityAlgorithmSuite.Basic256
              ' We do not want signature confirmation on the application level messages
              ' when secure conversation is enabled.
              secureconversation.RequireSignatureConfirmation = False
              secureconversation.MessageProtectionOrder = m_messageProtectionOrder
              secureconversation.SetKeyDerivation(m_requireDerivedKeys)
              securityBinding = secureconversation
      
          End If
      
          ' Add the security binding to the binding collection
          bec.Add(securityBinding)
      
          ' Add the message encoder.
          Dim textelement As New TextMessageEncodingBindingElement()
          textelement.MessageVersion = System.ServiceModel.Channels.MessageVersion.Soap11WSAddressingAugust2004
          'These are the defaults required for WSE
          'textelement.MessageVersion = MessageVersion.Soap11Addressing1;
          'textelement.WriteEncoding = System.Text.Encoding.UTF8;
          bec.Add(textelement)
      
          ' Add the transport
          bec.Add(transport)
      
          ' return the binding elements
          Return bec
      
      End Function
      
  3. No código do aplicativo cliente, inclua código para definir as propriedades de associação.

    O exemplo de código a seguir especifica que o cliente WCF deve usar proteção e autenticação de mensagens conforme definido pela declaração de segurança pronta para uso do WSE 3.0 AnonymousForCertificate. Além disso, são necessárias sessões seguras e chaves derivadas.

    static void CallWseService(bool usePolicyFile)
    {
        EndpointAddress address = new EndpointAddress(new Uri("http://localhost/WSSecurityAnonymousPolicy/WSSecurityAnonymousService.asmx"),
                                                      EndpointIdentity.CreateDnsIdentity("WSE2QuickStartServer"));
    
        WseHttpBinding binding = new WseHttpBinding();
        if (!usePolicyFile)
        {
            binding.SecurityAssertion = WseSecurityAssertion.AnonymousForCertificate;
            binding.EstablishSecurityContext = true;
            binding.RequireDerivedKeys = true;
            binding.MessageProtectionOrder = MessageProtectionOrder.SignBeforeEncrypt;
        }
        else
        {
            binding.LoadPolicy("..\\wse3policyCache.config", "ServerPolicy");
        }
    
        WSSecurityAnonymousServiceSoapClient client = new WSSecurityAnonymousServiceSoapClient(binding, address);
    
    Private Shared Sub CallWseService(ByVal usePolicyFile As Boolean)
    
        Dim address As New EndpointAddress(New Uri("http://localhost/WSSecurityAnonymousPolicy/WSSecurityAnonymousService.asmx"), EndpointIdentity.CreateDnsIdentity("WSE2QuickStartServer"))
    
        Dim binding As New WseHttpBinding()
        If Not usePolicyFile Then
    
            binding.SecurityAssertion = WseSecurityAssertion.AnonymousForCertificate
            binding.EstablishSecurityContext = True
            binding.RequireDerivedKeys = True
            binding.MessageProtectionOrder = MessageProtectionOrder.SignBeforeEncrypt
    
        Else
            binding.LoadPolicy("..\wse3policyCache.config", "ServerPolicy")
        End If
    
        Dim client As New WSSecurityAnonymousServiceSoapClient(binding, address)
    

Exemplo

O exemplo de código a seguir define uma associação personalizada que expõe propriedades que correspondem às propriedades de uma declaração de segurança pronta para uso do WSE 3.0. Essa associação personalizada, denominada WseHttpBinding, é então usada para especificar as propriedades de associação para um cliente WCF que se comunica com o exemplo WSSecurityAnonymous WSE 3.0 QuickStart.

Confira também