Cómo: Cambiar el proveedor criptográfico para la clave privada de un certificado X.509

Artículo
02/27/2011

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

El marco de seguridad WCF proporciona una manera de introducir nuevos tipos de token de seguridad tal y como se describe en Cómo: Crear 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

Defina una clase nueva derivada de la clase X509AsymmetricSecurityKey.
Reemplace la propiedad de solo lectura KeySize. Esta propiedad devuelve el tamaño de clave real del par de clave pública/privada del certificado.
Reemplace el método DecryptKey. El marco de seguridad 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.)
Reemplace el método GetAsymmetricAlgorithm. El marco de seguridad WCF llama a este método para obtener una instancia de la clase AsymmetricAlgorithm que representa el proveedor criptográfico para la clave privada o pública del certificado, según los parámetros pasados al método.
Opcional. Reemplace el método GetHashAlgorithmForSignature. Invalide este método si se requiere una implementación diferente de la clase HashAlgorithm.
Invalide el método GetSignatureFormatter. Este método devuelve una instancia de la clase AsymmetricSignatureFormatter que está asociada a la clave privada del certificado.

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

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

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)
                {
                    if (this.publicKey == null)
                    {
                        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;
        }
    }
}

El procedimiento siguiente muestra cómo integrar la implementación de clave de seguridad asimétrica personalizada X.509, creada en el procedimiento anterior con el marco de seguridad WCF para 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.

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 obtener más información sobre tokens de seguridad personalizados, consulte Cómo: Crear un token personalizado.

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

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;
        }
    }
}

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 obtener más información a cerca de proveedores de tokens de seguridad personalizados, consulte Cómo crear un proveedor de tokens de seguridad personalizado.

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

class CustomX509SecurityTokenProvider : SecurityTokenProvider
{
    X509Certificate2 certificate;

    public CustomX509SecurityTokenProvider(X509Certificate2 certificate)
    {
        this.certificate = certificate;
    }

    protected override SecurityToken GetTokenCore(TimeSpan timeout)
    {
        return new CustomX509SecurityToken(certificate);
    }
}

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 obtener más información a cerca de las credenciales del cliente personalizadas y administradores de tokens de seguridad del cliente, consulte Tutorial: Crear credenciales de cliente y servicio personalizadas.

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

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);
                }
            }
        }

        if (result == null)
        {
            result = base.CreateSecurityTokenProvider(tokenRequirement);
        }
        return result;
    }
}

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

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);
    }
}

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 obtener más información a cerca de las credenciales de servicio personalizadas y administradores de tokens de seguridad de servicio, consulte Tutorial: Crear credenciales de cliente y servicio personalizadas.

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

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);
                }
            }
        }

        if (result == null)
        {
            result = base.CreateSecurityTokenProvider(tokenRequirement);
        }
        return result;
    }
}

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

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);
    }
}

Vea también

Compartir a través de

Cómo: Cambiar el proveedor criptográfico para la clave privada de un certificado X.509

Procedimientos

Crear una clave asimétrica X.509 personalizada

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

Vea también

Tareas

Referencia

Conceptos

Recursos adicionales