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Procedimiento para cambiar el proveedor criptográfico para la clave privada de un certificado X.509

En este tema se muestra cómo cambiar el proveedor criptográfico usado para proporcionar la clave privada de un certificado X.509 y cómo integrar el proveedor en el marco de seguridad de Windows Communication Foundation (WCF). Para más información sobre el uso de certificados, consulte Trabajar con certificados.

El marco de seguridad de WCF proporciona una manera de introducir nuevos tipos de token de seguridad como se describe en Creación de un token personalizado. También es posible utilizar un token personalizado para reemplazar los tipos existentes de token proporcionados por el sistema.

En este tema, un token X.509 personalizado que proporciona una implementación diferente para la clave privada del certificado reemplaza el token de seguridad X.509 proporcionado por el sistema. Esto es útil en escenarios donde un proveedor criptográfico diferente al proveedor criptográfico predeterminado de Windows proporciona la clave privada real. Un ejemplo de un proveedor criptográfico alternativo es un módulo de seguridad de hardware que lleva a cabo todas las operaciones criptográficas relacionadas con clave privada, y no almacena las claves privadas en memoria, de modo que mejora la seguridad del sistema.

El siguiente ejemplo solamente sirve de demostración. No reemplaza el proveedor criptográfico predeterminado de Windows, pero muestra donde se pudo integrar este tipo de proveedor.

Procedimientos

Cada token de seguridad que tiene una clave o claves de seguridad asociadas debe implementar la propiedad SecurityKeys, que devuelve una colección de claves desde la instancia del token de seguridad. Si el token es un token de seguridad X.509, la colección contiene una instancia única de la clase X509AsymmetricSecurityKey que representa claves públicas y claves privadas asociadas al certificado. Para reemplazar el proveedor criptográfico predeterminado utilizado para proporcionar las claves del certificado, cree una nueva implementación de esta clase.

Crear una clave asimétrica X.509 personalizada

  1. Defina una clase nueva derivada de la clase X509AsymmetricSecurityKey.

  2. Reemplace la propiedad de solo lectura KeySize. Esta propiedad devuelve el tamaño de clave real del par de clave pública/privada del certificado.

  3. Invalide el método DecryptKey . El marco de seguridad de WCF llama a este método para descifrar una clave simétrica con la clave privada del certificado. (La clave se cifró previamente con la clave pública del certificado.)

  4. Invalide el método GetAsymmetricAlgorithm . El marco de seguridad de WCF llama a este método para obtener una instancia de la clase AsymmetricAlgorithm que representa el proveedor criptográfico de la clave privada o pública del certificado, según los parámetros pasados al método.

  5. Opcional. Invalide el método GetHashAlgorithmForSignature . Invalide este método si se requiere una implementación diferente de la clase HashAlgorithm.

  6. Invalide el método GetSignatureFormatter . Este método devuelve una instancia de la clase AsymmetricSignatureFormatter que está asociada a la clave privada del certificado.

  7. Invalide el método IsSupportedAlgorithm . Este método se utiliza para indicar si la implementación de clave de seguridad admite un algoritmo criptográfico determinado.

    class CustomX509AsymmetricSecurityKey : X509AsymmetricSecurityKey
    {
        X509Certificate2 certificate;
        object thisLock = new Object();
        bool privateKeyAvailabilityDetermined;
        AsymmetricAlgorithm privateKey;
        PublicKey publicKey;
    
        public CustomX509AsymmetricSecurityKey(X509Certificate2 certificate)
            : base(certificate)
        {
            this.certificate = certificate;
        }
    
        public override int KeySize
        {
            get { return this.PublicKey.Key.KeySize; }
        }
    
        AsymmetricAlgorithm PrivateKey
        {
            // You need to modify this to obtain the private key using a different cryptographic
            // provider if you do not want to use the default provider.
            get
            {
                if (!this.privateKeyAvailabilityDetermined)
                {
                    lock (ThisLock)
                    {
                        if (!this.privateKeyAvailabilityDetermined)
                        {
                            this.privateKey = this.certificate.PrivateKey;
                            this.privateKeyAvailabilityDetermined = true;
                        }
                    }
                }
                return this.privateKey;
            }
        }
    
        PublicKey PublicKey
        {
            get
            {
                if (this.publicKey == null)
                {
                    lock (ThisLock)
                    {
                        this.publicKey ??= this.certificate.PublicKey;
                    }
                }
                return this.publicKey;
            }
        }
    
        Object ThisLock
        {
            get
            {
                return thisLock;
            }
        }
    
        public override byte[] DecryptKey(string algorithm, byte[] keyData)
        {
            // You can decrypt the key only if you have the private key in the certificate.
            if (this.PrivateKey == null)
            {
                throw new NotSupportedException("Missing private key");
            }
    
            RSA rsa = this.PrivateKey as RSA;
            if (rsa == null)
            {
                throw new NotSupportedException("Private key cannot be used with RSA algorithm");
            }
    
            // Support exchange keySpec, AT_EXCHANGE ?
            if (rsa.KeyExchangeAlgorithm == null)
            {
                throw new NotSupportedException("Private key does not support key exchange");
            }
    
            switch (algorithm)
            {
                case EncryptedXml.XmlEncRSA15Url:
                    return EncryptedXml.DecryptKey(keyData, rsa, false);
    
                case EncryptedXml.XmlEncRSAOAEPUrl:
                    return EncryptedXml.DecryptKey(keyData, rsa, true);
    
                default:
                    throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
            }
        }
    
        public override AsymmetricAlgorithm GetAsymmetricAlgorithm(string algorithm, bool privateKey)
        {
            if (privateKey)
            {
                if (this.PrivateKey == null)
                {
                    throw new NotSupportedException("Missing private key");
                }
    
                switch (algorithm)
                {
                    case SignedXml.XmlDsigDSAUrl:
                        if ((this.PrivateKey as DSA) != null)
                        {
                            return (this.PrivateKey as DSA);
                        }
                        throw new NotSupportedException("Private key cannot be used with DSA");
    
                    case SignedXml.XmlDsigRSASHA1Url:
                    case EncryptedXml.XmlEncRSA15Url:
                    case EncryptedXml.XmlEncRSAOAEPUrl:
                        if ((this.PrivateKey as RSA) != null)
                        {
                            return (this.PrivateKey as RSA);
                        }
                        throw new NotSupportedException("Private key cannot be used with RSA");
                    default:
                        throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
                }
            }
            else
            {
                switch (algorithm)
                {
                    case SignedXml.XmlDsigDSAUrl:
                        if ((this.PublicKey.Key as DSA) != null)
                        {
                            return (this.PublicKey.Key as DSA);
                        }
                        throw new NotSupportedException("Public key cannot be used with DSA");
                    case SignedXml.XmlDsigRSASHA1Url:
                    case EncryptedXml.XmlEncRSA15Url:
                    case EncryptedXml.XmlEncRSAOAEPUrl:
                        if ((this.PublicKey.Key as RSA) != null)
                        {
                            return (this.PublicKey.Key as RSA);
                        }
                        throw new NotSupportedException("Public key cannot be used with RSA");
                    default:
                        throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
                }
            }
        }
    
        public override HashAlgorithm GetHashAlgorithmForSignature(string algorithm)
        {
            if (!this.IsSupportedAlgorithm(algorithm))
            {
                throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
            }
    
            switch (algorithm)
            {
                case SignedXml.XmlDsigDSAUrl:
                case SignedXml.XmlDsigRSASHA1Url:
                    return new SHA1Managed();
                default:
                    throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
            }
        }
    
        public override AsymmetricSignatureFormatter GetSignatureFormatter(string algorithm)
        {
            // The signature can be created only if the private key is present.
            if (this.PrivateKey == null)
            {
                throw new NotSupportedException("Private key is missing");
            }
    
            // Only one of the two algorithms is supported, not both.
            //     XmlDsigDSAUrl = "http://www.w3.org/2000/09/xmldsig#dsa-sha1";
            //     XmlDsigRSASHA1Url = "http://www.w3.org/2000/09/xmldsig#rsa-sha1";
            switch (algorithm)
            {
                case SignedXml.XmlDsigDSAUrl:
    
                    // Ensure that this is a DSA algorithm object.
                    DSA dsa = (this.PrivateKey as DSA);
                    if (dsa == null)
                    {
                        throw new NotSupportedException("Private key cannot be used DSA");
                    }
    
                    return new DSASignatureFormatter(dsa);
    
                case SignedXml.XmlDsigRSASHA1Url:
                    // Ensure that this is an RSA algorithm object.
                    RSA rsa = (this.PrivateKey as RSA);
                    if (rsa == null)
                    {
                        throw new NotSupportedException("Private key cannot be used RSA");
                    }
    
                    return new RSAPKCS1SignatureFormatter(rsa);
                default:
                    throw new NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm));
            }
        }
    
        public override bool IsSupportedAlgorithm(string algorithm)
        {
            switch (algorithm)
            {
                case SignedXml.XmlDsigDSAUrl:
                    return (this.PublicKey.Key is DSA);
    
                case SignedXml.XmlDsigRSASHA1Url:
                case EncryptedXml.XmlEncRSA15Url:
                case EncryptedXml.XmlEncRSAOAEPUrl:
                    return (this.PublicKey.Key is RSA);
    
                default:
                    return false;
            }
        }
    }
    
    Friend Class CustomX509AsymmetricSecurityKey
        Inherits X509AsymmetricSecurityKey
    
        Private _certificate As X509Certificate2
        Private _thisLock As New Object()
        Private _privateKeyAvailabilityDetermined As Boolean
        Private _privateKey As AsymmetricAlgorithm
        Private _publicKey As PublicKey
    
        Public Sub New(ByVal certificate As X509Certificate2)
            MyBase.New(certificate)
            Me._certificate = certificate
        End Sub
    
        Public Overrides ReadOnly Property KeySize() As Integer
            Get
                Return Me.PublicKey.Key.KeySize
            End Get
        End Property
    
        Private Overloads ReadOnly Property PrivateKey() As AsymmetricAlgorithm
            ' You need to modify this to obtain the private key using a different cryptographic
            ' provider if you do not want to use the default provider.
            Get
                If Not Me._privateKeyAvailabilityDetermined Then
                    SyncLock ThisLock
                        If Not Me._privateKeyAvailabilityDetermined Then
                            Me._privateKey = Me._certificate.PrivateKey
                            Me._privateKeyAvailabilityDetermined = True
                        End If
                    End SyncLock
                End If
                Return Me._privateKey
            End Get
        End Property
    
        Private Overloads ReadOnly Property PublicKey() As PublicKey
            Get
                If Me._publicKey Is Nothing Then
                    SyncLock ThisLock
                        If Me._publicKey Is Nothing Then
                            Me._publicKey = Me._certificate.PublicKey
                        End If
                    End SyncLock
                End If
                Return Me._publicKey
            End Get
        End Property
    
        Private Overloads ReadOnly Property ThisLock() As Object
            Get
                Return _thisLock
            End Get
        End Property
    
        Public Overrides Function DecryptKey(ByVal algorithm As String, _
                                             ByVal keyData() As Byte) As Byte()
            ' You can decrypt the key only if you have the private key in the certificate.
            If Me.PrivateKey Is Nothing Then
                Throw New NotSupportedException("Missing private key")
            End If
    
            Dim rsa = TryCast(Me.PrivateKey, RSA)
            If rsa Is Nothing Then
                Throw New NotSupportedException("Private key cannot be used with RSA algorithm")
            End If
    
            ' Support exchange keySpec, AT_EXCHANGE ?
            If rsa.KeyExchangeAlgorithm Is Nothing Then
                Throw New NotSupportedException("Private key does not support key exchange")
            End If
    
            Select Case algorithm
                Case EncryptedXml.XmlEncRSA15Url
                    Return EncryptedXml.DecryptKey(keyData, rsa, False)
    
                Case EncryptedXml.XmlEncRSAOAEPUrl
                    Return EncryptedXml.DecryptKey(keyData, rsa, True)
    
                Case Else
                    Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
            End Select
        End Function
    
        Public Overrides Function GetAsymmetricAlgorithm(ByVal algorithm As String, _
                                                         ByVal privateKey As Boolean) As AsymmetricAlgorithm
            If privateKey Then
                If Me.PrivateKey Is Nothing Then
                    Throw New NotSupportedException("Missing private key")
                End If
    
                Select Case algorithm
                    Case SignedXml.XmlDsigDSAUrl
                        If TryCast(Me.PrivateKey, DSA) IsNot Nothing Then
                            Return (TryCast(Me.PrivateKey, DSA))
                        End If
                        Throw New NotSupportedException("Private key cannot be used with DSA")
    
                    Case SignedXml.XmlDsigRSASHA1Url, EncryptedXml.XmlEncRSA15Url, EncryptedXml.XmlEncRSAOAEPUrl
                        If TryCast(Me.PrivateKey, RSA) IsNot Nothing Then
                            Return (TryCast(Me.PrivateKey, RSA))
                        End If
                        Throw New NotSupportedException("Private key cannot be used with RSA")
                    Case Else
                        Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
                End Select
            Else
                Select Case algorithm
                    Case SignedXml.XmlDsigDSAUrl
                        If TryCast(Me.PublicKey.Key, DSA) IsNot Nothing Then
                            Return (TryCast(Me.PublicKey.Key, DSA))
                        End If
                        Throw New NotSupportedException("Public key cannot be used with DSA")
                    Case SignedXml.XmlDsigRSASHA1Url, EncryptedXml.XmlEncRSA15Url, EncryptedXml.XmlEncRSAOAEPUrl
                        If TryCast(Me.PublicKey.Key, RSA) IsNot Nothing Then
                            Return (TryCast(Me.PublicKey.Key, RSA))
                        End If
                        Throw New NotSupportedException("Public key cannot be used with RSA")
                    Case Else
                        Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
                End Select
            End If
        End Function
    
        Public Overrides Function GetHashAlgorithmForSignature(ByVal algorithm As String) As HashAlgorithm
            If Not Me.IsSupportedAlgorithm(algorithm) Then
                Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
            End If
    
            Select Case algorithm
                Case SignedXml.XmlDsigDSAUrl, SignedXml.XmlDsigRSASHA1Url
                    Return New SHA1Managed()
                Case Else
                    Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
            End Select
        End Function
    
        Public Overrides Function GetSignatureFormatter(ByVal algorithm As String) As AsymmetricSignatureFormatter
            ' The signature can be created only if the private key is present.
            If Me.PrivateKey Is Nothing Then
                Throw New NotSupportedException("Private key is missing")
            End If
    
            ' Only one of the two algorithms is supported, not both.
            '     XmlDsigDSAUrl = "http://www.w3.org/2000/09/xmldsig#dsa-sha1";
            '     XmlDsigRSASHA1Url = "http://www.w3.org/2000/09/xmldsig#rsa-sha1";
            Select Case algorithm
                Case SignedXml.XmlDsigDSAUrl
    
                    ' Ensure that this is a DSA algorithm object.
                    Dim dsa = (TryCast(Me.PrivateKey, DSA))
                    If dsa Is Nothing Then
                        Throw New NotSupportedException("Private key cannot be used DSA")
                    End If
    
                    Return New DSASignatureFormatter(dsa)
    
                Case SignedXml.XmlDsigRSASHA1Url
                    ' Ensure that this is an RSA algorithm object.
                    Dim rsa = (TryCast(Me.PrivateKey, RSA))
                    If rsa Is Nothing Then
                        Throw New NotSupportedException("Private key cannot be used RSA")
                    End If
    
                    Return New RSAPKCS1SignatureFormatter(rsa)
                Case Else
                    Throw New NotSupportedException(String.Format("Algorithm {0} is not supported", algorithm))
            End Select
        End Function
    
        Public Overrides Function IsSupportedAlgorithm(ByVal algorithm As String) As Boolean
            Select Case algorithm
                Case SignedXml.XmlDsigDSAUrl
                    Return (TypeOf Me.PublicKey.Key Is DSA)
    
                Case SignedXml.XmlDsigRSASHA1Url, EncryptedXml.XmlEncRSA15Url, EncryptedXml.XmlEncRSAOAEPUrl
                    Return (TypeOf Me.PublicKey.Key Is RSA)
    
                Case Else
                    Return False
            End Select
        End Function
    
    End Class
    

El procedimiento siguiente muestra cómo integrar la implementación de claves de seguridad asimétricas personalizadas X.509, creada en el procedimiento anterior, con el marco de seguridad de WCF a fin de reemplazar el token de seguridad X.509 proporcionado por el sistema.

Reemplazar el token de seguridad X.509 proporcionado por el sistema por un token clave de seguridad asimétrico personalizado X.509.

  1. Cree un token de seguridad X.509 personalizado que devuelve la clave de seguridad asimétrica personalizada X.509 en lugar de la clave de seguridad proporcionada por el sistema, tal y como se muestra en el ejemplo siguiente. Para más información sobre los tokens de seguridad personalizados, consulte Creación de un token personalizado.

    class CustomX509SecurityToken : X509SecurityToken
    {
        ReadOnlyCollection<SecurityKey> securityKeys;
        public CustomX509SecurityToken(X509Certificate2 certificate)
            : base(certificate)
        {
        }
    
        public override ReadOnlyCollection<SecurityKey> SecurityKeys
        {
            get
            {
                if (this.securityKeys == null)
                {
                    List<SecurityKey> temp = new List<SecurityKey>(1);
                    temp.Add(new CustomX509AsymmetricSecurityKey(this.Certificate));
                    this.securityKeys = temp.AsReadOnly();
                }
                return this.securityKeys;
            }
        }
    }
    
    Friend Class CustomX509SecurityToken
        Inherits X509SecurityToken
    
        Private _securityKeys As ReadOnlyCollection(Of SecurityKey)
    
        Public Sub New(ByVal certificate As X509Certificate2)
            MyBase.New(certificate)
        End Sub
    
        Public Overrides ReadOnly Property SecurityKeys() As ReadOnlyCollection(Of SecurityKey)
            Get
                If Me._securityKeys Is Nothing Then
                    Dim temp As New List(Of SecurityKey)(1)
                    temp.Add(New CustomX509AsymmetricSecurityKey(Me.Certificate))
                    Me._securityKeys = temp.AsReadOnly()
                End If
                Return Me._securityKeys
            End Get
        End Property
    
    End Class
    
  2. Cree un proveedor de token de seguridad personalizado que devuelve un token de seguridad X.509 personalizado, tal y como se muestra en el ejemplo. Para más información sobre los proveedores de tokens de seguridad personalizados, consulte Creación de un proveedor de tokens de seguridad personalizados.

    class CustomX509SecurityTokenProvider : SecurityTokenProvider
    {
        X509Certificate2 certificate;
    
        public CustomX509SecurityTokenProvider(X509Certificate2 certificate)
        {
            this.certificate = certificate;
        }
    
        protected override SecurityToken GetTokenCore(TimeSpan timeout)
        {
            return new CustomX509SecurityToken(certificate);
        }
    }
    
    Friend Class CustomX509SecurityTokenProvider
        Inherits SecurityTokenProvider
    
        Private _certificate As X509Certificate2
    
        Public Sub New(ByVal certificate As X509Certificate2)
            Me._certificate = certificate
        End Sub
    
        Protected Overrides Function GetTokenCore(ByVal timeout As TimeSpan) As SecurityToken
            Return New CustomX509SecurityToken(_certificate)
        End Function
    End Class
    
  3. Si es necesario utilizar la clave de seguridad personalizada en el lado del iniciador, cree un administrador de tokens de seguridad de cliente personalizados y las clases de credenciales de cliente personalizadas, tal y como se muestra en el ejemplo siguiente. Para más información sobre las credenciales de cliente personalizadas y los administradores de tokens de seguridad de cliente, consulte Tutorial: Creación de credenciales de cliente y servicio personalizadas.

    class CustomClientSecurityTokenManager : ClientCredentialsSecurityTokenManager
    {
        CustomClientCredentials credentials;
    
        public CustomClientSecurityTokenManager(CustomClientCredentials credentials)
            : base(credentials)
        {
            this.credentials = credentials;
        }
    
        public override SecurityTokenProvider CreateSecurityTokenProvider(SecurityTokenRequirement tokenRequirement)
        {
            SecurityTokenProvider result = null;
    
            if (tokenRequirement.TokenType == SecurityTokenTypes.X509Certificate)
            {
                MessageDirection direction = tokenRequirement.GetProperty<MessageDirection>(ServiceModelSecurityTokenRequirement.MessageDirectionProperty);
                if (direction == MessageDirection.Output)
                {
                    if (tokenRequirement.KeyUsage == SecurityKeyUsage.Signature)
                    {
                        result = new CustomX509SecurityTokenProvider(credentials.ClientCertificate.Certificate);
                    }
                }
                else
                {
                    if (tokenRequirement.KeyUsage == SecurityKeyUsage.Exchange)
                    {
                        result = new CustomX509SecurityTokenProvider(credentials.ClientCertificate.Certificate);
                    }
                }
            }
    
            result ??= base.CreateSecurityTokenProvider(tokenRequirement);
            return result;
        }
    }
    
    Friend Class CustomClientSecurityTokenManager
        Inherits ClientCredentialsSecurityTokenManager
    
        Private credentials As CustomClientCredentials
    
        Public Sub New(ByVal credentials As CustomClientCredentials)
            MyBase.New(credentials)
            Me.credentials = credentials
        End Sub
    
        Public Overrides Function CreateSecurityTokenProvider(ByVal tokenRequirement As SecurityTokenRequirement) _
        As SecurityTokenProvider
            Dim result As SecurityTokenProvider = Nothing
    
            If tokenRequirement.TokenType = SecurityTokenTypes.X509Certificate Then
                Dim direction = tokenRequirement.GetProperty(Of MessageDirection) _
                (ServiceModelSecurityTokenRequirement.MessageDirectionProperty)
                If direction = MessageDirection.Output Then
                    If tokenRequirement.KeyUsage = SecurityKeyUsage.Signature Then
                        result = New CustomX509SecurityTokenProvider(credentials.ClientCertificate.Certificate)
                    End If
                Else
                    If tokenRequirement.KeyUsage = SecurityKeyUsage.Exchange Then
                        result = New CustomX509SecurityTokenProvider(credentials.ClientCertificate.Certificate)
                    End If
                End If
            End If
    
            If result Is Nothing Then
                result = MyBase.CreateSecurityTokenProvider(tokenRequirement)
            End If
            Return result
        End Function
    End Class
    
    public class CustomClientCredentials : ClientCredentials
    {
        public CustomClientCredentials()
        {
        }
    
        protected CustomClientCredentials(CustomClientCredentials other)
            : base(other)
        {
        }
    
        protected override ClientCredentials CloneCore()
        {
            return new CustomClientCredentials(this);
        }
    
        public override SecurityTokenManager CreateSecurityTokenManager()
        {
            return new CustomClientSecurityTokenManager(this);
        }
    }
    
    Public Class CustomClientCredentials
        Inherits ClientCredentials
    
        Public Sub New()
        End Sub
    
        Protected Sub New(ByVal other As CustomClientCredentials)
            MyBase.New(other)
        End Sub
    
        Protected Overrides Function CloneCore() As ClientCredentials
            Return New CustomClientCredentials(Me)
        End Function
    
        Public Overrides Function CreateSecurityTokenManager() As SecurityTokenManager
            Return New CustomClientSecurityTokenManager(Me)
        End Function
    End Class
    
  4. Si es necesario utilizar la clave de seguridad personalizada en el lado del receptor, cree un administrador de tokens de seguridad de servicio personalizados y las clases de credenciales de servicio personalizadas, tal y como se muestra en el ejemplo siguiente. Para más información sobre las credenciales de servicio personalizadas y los administradores de tokens de seguridad de servicio, consulte Tutorial: Creación de credenciales de cliente y servicio personalizadas.

    class CustomServiceSecurityTokenManager : ServiceCredentialsSecurityTokenManager
    {
        CustomServiceCredentials credentials;
    
        public CustomServiceSecurityTokenManager(CustomServiceCredentials credentials)
            : base(credentials)
        {
            this.credentials = credentials;
        }
    
        public override SecurityTokenProvider CreateSecurityTokenProvider(SecurityTokenRequirement tokenRequirement)
        {
            SecurityTokenProvider result = null;
    
            if (tokenRequirement.TokenType == SecurityTokenTypes.X509Certificate)
            {
                MessageDirection direction = tokenRequirement.GetProperty<MessageDirection>(ServiceModelSecurityTokenRequirement.MessageDirectionProperty);
                if (direction == MessageDirection.Input)
                {
                    if (tokenRequirement.KeyUsage == SecurityKeyUsage.Exchange)
                    {
                        result = new CustomX509SecurityTokenProvider(credentials.ServiceCertificate.Certificate);
                    }
                }
                else
                {
                    if (tokenRequirement.KeyUsage == SecurityKeyUsage.Signature)
                    {
                        result = new CustomX509SecurityTokenProvider(credentials.ServiceCertificate.Certificate);
                    }
                }
            }
    
            result ??= base.CreateSecurityTokenProvider(tokenRequirement);
            return result;
        }
    }
    
    Friend Class CustomServiceSecurityTokenManager
        Inherits ServiceCredentialsSecurityTokenManager
    
        Private credentials As CustomServiceCredentials
    
        Public Sub New(ByVal credentials As CustomServiceCredentials)
            MyBase.New(credentials)
            Me.credentials = credentials
        End Sub
    
        Public Overrides Function CreateSecurityTokenProvider(ByVal tokenRequirement As SecurityTokenRequirement) As SecurityTokenProvider
            Dim result As SecurityTokenProvider = Nothing
    
            If tokenRequirement.TokenType = SecurityTokenTypes.X509Certificate Then
                Dim direction = tokenRequirement.GetProperty(Of MessageDirection) _
                (ServiceModelSecurityTokenRequirement.MessageDirectionProperty)
                If direction = MessageDirection.Input Then
                    If tokenRequirement.KeyUsage = SecurityKeyUsage.Exchange Then
                        result = New CustomX509SecurityTokenProvider(credentials.ServiceCertificate.Certificate)
                    End If
                Else
                    If tokenRequirement.KeyUsage = SecurityKeyUsage.Signature Then
                        result = New CustomX509SecurityTokenProvider(credentials.ServiceCertificate.Certificate)
                    End If
                End If
            End If
    
            If result Is Nothing Then
                result = MyBase.CreateSecurityTokenProvider(tokenRequirement)
            End If
            Return result
        End Function
    End Class
    
    public class CustomServiceCredentials : ServiceCredentials
    {
        public CustomServiceCredentials()
        {
        }
    
        protected CustomServiceCredentials(CustomServiceCredentials other)
            : base(other)
        {
        }
    
        protected override ServiceCredentials CloneCore()
        {
            return new CustomServiceCredentials(this);
        }
    
        public override SecurityTokenManager CreateSecurityTokenManager()
        {
            return new CustomServiceSecurityTokenManager(this);
        }
    }
    
    Public Class CustomServiceCredentials
        Inherits ServiceCredentials
    
        Public Sub New()
        End Sub
    
        Protected Sub New(ByVal other As CustomServiceCredentials)
            MyBase.New(other)
        End Sub
    
        Protected Overrides Function CloneCore() As ServiceCredentials
            Return New CustomServiceCredentials(Me)
        End Function
    
        Public Overrides Function CreateSecurityTokenManager() As SecurityTokenManager
            Return New CustomServiceSecurityTokenManager(Me)
        End Function
    
    End Class
    

Consulte también