DataProtector DataProtector DataProtector DataProtector Class

Definice

Poskytuje základní třídu pro ochrany dat.Provides the base class for data protectors.

public ref class DataProtector abstract
public abstract class DataProtector
type DataProtector = class
Public MustInherit Class DataProtector
Dědičnost
DataProtectorDataProtectorDataProtectorDataProtector
Odvozené

Příklady

Následující příklad ukazuje, jak vytvořit ochranu dat, která používá třídu ochrany s možností pro další entropii.The following example demonstrates how to create a data protector that uses a protection class with an option for extra entropy. Ve výchozím nastavení DataProtector třída předřadí hodnotu hash vlastností účelu k datům, která mají být zašifrována.By default, the DataProtector class prepends the hash of the purpose properties to the data to be encrypted. Tuto funkci můžete vypnout a při volání ochrany dat s další možností entropie použít účel hash jako dodatečnou entropii.You can turn that functionality off and use the hashed purpose as extra entropy when calling a data protector with an extra entropy option.

using System;
using System.Security.Permissions;

namespace System.Security.Cryptography
{
    public sealed class MyDataProtector : DataProtector
    {
        public DataProtectionScope Scope { get; set; }
        // This implementation gets the HashedPurpose from the base class and passes it as OptionalEntropy to ProtectedData.
        // The default for DataProtector is to prepend the hash to the plain text, but because we are using the hash 
        // as OptionalEntropy there is no need to prepend it.
        protected override bool PrependHashedPurposeToPlaintext
        {
            get
            {
                return false;
            }
        }
        // To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
        // in the constructor, but Assert the permission when ProviderProtect is called.  This is similar to FileStream
        // where access is checked at time of creation, not time of use.
        [SecuritySafeCritical]
        [DataProtectionPermission(SecurityAction.Assert, ProtectData = true)]
        protected override byte[] ProviderProtect(byte[] userData)
        {
            // Delegate to ProtectedData
            return ProtectedData.Protect(userData, GetHashedPurpose(), Scope);
        }
        // To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
        // in the constructor, but Assert the permission when ProviderUnProtect is called.  This is similar to FileStream
        // where access is checked at time of creation, not time of use.
        [SecuritySafeCritical]
        [DataProtectionPermission(SecurityAction.Assert, UnprotectData = true)]
        protected override byte[] ProviderUnprotect(byte[] encryptedData)
        {
            // Delegate to ProtectedData
            return ProtectedData.Unprotect(encryptedData, GetHashedPurpose(), Scope);
        }
        public override bool IsReprotectRequired(byte[] encryptedData)
        {
            // For now, this cannot be determined, so always return true;
            return true;
        }
        // Public constructor
        // The Demand for DataProtectionPermission is in the constructor because we Assert this permission 
        // in the ProviderProtect/ProviderUnprotect methods. 
        [DataProtectionPermission(SecurityAction.Demand, Unrestricted = true)]
        [SecuritySafeCritical]
        public MyDataProtector(string appName, string primaryPurpose, params string[] specificPurpose)
            : base(appName, primaryPurpose, specificPurpose)
        {
        }
    }
}
Imports System.Security
Imports System.Security.Cryptography
Imports System.Security.Permissions



Public NotInheritable Class MyDataProtector
    Inherits DataProtector

    Public Property Scope() As DataProtectionScope
        Get
            Return Scope
        End Get
        Set(value As DataProtectionScope)
        End Set
    End Property ' This implementation gets the HashedPurpose from the base class and passes it as OptionalEntropy to ProtectedData.
    ' The default for DataProtector is to prepend the hash to the plain text, but because we are using the hash 
    ' as OptionalEntropy there is no need to prepend it.

    Protected Overrides ReadOnly Property PrependHashedPurposeToPlaintext() As Boolean
        Get
            Return False
        End Get
    End Property

    ' To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
    ' in the constructor, but Assert the permission when ProviderProtect is called.  This is similar to FileStream
    ' where access is checked at time of creation, not time of use.
    <SecuritySafeCritical(), DataProtectionPermission(SecurityAction.Assert, ProtectData:=True)> _
    Protected Overrides Function ProviderProtect(ByVal userData() As Byte) As Byte()
        ' Delegate to ProtectedData
        Return ProtectedData.Protect(userData, GetHashedPurpose(), Scope)

    End Function 'ProviderProtect

    ' To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
    ' in the constructor, but Assert the permission when ProviderUnProtect is called.  This is similar to FileStream
    ' where access is checked at time of creation, not time of use.
    <SecuritySafeCritical(), DataProtectionPermission(SecurityAction.Assert, UnprotectData:=True)> _
    Protected Overrides Function ProviderUnprotect(ByVal encryptedData() As Byte) As Byte()
        ' Delegate to ProtectedData
        Return ProtectedData.Unprotect(encryptedData, GetHashedPurpose(), Scope)

    End Function 'ProviderUnprotect

    Public Overrides Function IsReprotectRequired(ByVal encryptedData() As Byte) As Boolean
        ' For now, this cannot be determined, so always return true;
        Return True

    End Function 'IsReprotectRequired

    ' Public constructor
    ' The Demand for DataProtectionPermission is in the constructor because we Assert this permission 
    ' in the ProviderProtect/ProviderUnprotect methods. 
    <DataProtectionPermission(SecurityAction.Demand, Unrestricted:=True), SecuritySafeCritical()> _
    Public Sub New(ByVal appName As String, ByVal primaryPurpose As String, ParamArray specificPurpose() As String)
        MyBase.New(appName, primaryPurpose, specificPurpose)

    End Sub
End Class

Následující příklad ukazuje jednoduchou ochranu dat, která používá PrependHashedPurposeToPlaintext funkce DataProtector třídy.The following example demonstrates a simple data protector that uses the PrependHashedPurposeToPlaintext functionality of the DataProtector class.

using System;
using System.Security.Permissions;

namespace System.Security.Cryptography
{
    public sealed class MemoryProtector : DataProtector
    {
        public MemoryProtectionScope Scope { get; set; }
        protected override bool PrependHashedPurposeToPlaintext 
        {
            get
            {
                // Signal the DataProtector to prepend the hash of the purpose to the data.
                return true;
            }
        }
        // To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
        // in the constructor, but Assert the permission when ProviderProtect is called.  This is similar to FileStream
        // where access is checked at time of creation, not time of use.
        [SecuritySafeCritical]
        [DataProtectionPermission(SecurityAction.Assert, ProtectData = true)]
        protected override byte[] ProviderProtect(byte[] userData)
        {
            
            // Delegate to ProtectedData
            ProtectedMemory.Protect(userData, Scope);
            return userData;
        }
        // To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
        // in the constructor, but Assert the permission when ProviderUnprotect is called..  This is similar to FileStream
        // where access is checked at time of creation, not time of use.
        [SecuritySafeCritical]
        [DataProtectionPermission(SecurityAction.Assert, UnprotectData = true)]
        protected override byte[] ProviderUnprotect(byte[] encryptedData)
        {

            ProtectedMemory.Unprotect(encryptedData,Scope);           
                return encryptedData;
        }

        public override bool IsReprotectRequired(byte[] encryptedData)
        {
            // For now, this cannot be determined so always return true.
            return true;
        }
        // Public constructor
        // The Demand for DataProtectionPermission is in the constructor because we Assert this permission 
        // in the ProviderProtect/ProviderUnprotect methods. 
        [DataProtectionPermission(SecurityAction.Demand, Unrestricted = true)]
        [SecuritySafeCritical]
        public MemoryProtector(string appName, string primaryPurpose, params string[] specificPurpose)
            : base(appName, primaryPurpose, specificPurpose)
        {
        }
    }
}
Imports System.Security
Imports System.Security.Permissions
Imports System.Security.Cryptography



Public NotInheritable Class MemoryProtector
    Inherits DataProtector

    Public Property Scope() As MemoryProtectionScope
        Get
            Return Scope
        End Get
        Set(value As MemoryProtectionScope)
        End Set
    End Property

    Protected Overrides ReadOnly Property PrependHashedPurposeToPlaintext() As Boolean
        Get
            ' Signal the DataProtector to prepend the hash of the purpose to the data.
            Return True
        End Get
    End Property

    ' To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
    ' in the constructor, but Assert the permission when ProviderProtect is called.  This is similar to FileStream
    ' where access is checked at time of creation, not time of use.
    <SecuritySafeCritical(), DataProtectionPermission(SecurityAction.Assert, ProtectData:=True)> _
    Protected Overrides Function ProviderProtect(ByVal userData() As Byte) As Byte()

        ' Delegate to ProtectedData
        ProtectedMemory.Protect(userData, Scope)
        Return userData

    End Function 'ProviderProtect

    ' To allow a service to hand out instances of a DataProtector we demand unrestricted DataProtectionPermission 
    ' in the constructor, but Assert the permission when ProviderUnprotect is called..  This is similar to FileStream
    ' where access is checked at time of creation, not time of use.
    <SecuritySafeCritical(), DataProtectionPermission(SecurityAction.Assert, UnprotectData:=True)> _
    Protected Overrides Function ProviderUnprotect(ByVal encryptedData() As Byte) As Byte()

        ProtectedMemory.Unprotect(encryptedData, Scope)
        Return encryptedData

    End Function 'ProviderUnprotect

    Public Overrides Function IsReprotectRequired(ByVal encryptedData() As Byte) As Boolean
        ' For now, this cannot be determined so always return true.
        Return True

    End Function 'IsReprotectRequired

    ' Public constructor
    ' The Demand for DataProtectionPermission is in the constructor because we Assert this permission 
    ' in the ProviderProtect/ProviderUnprotect methods. 
    <DataProtectionPermission(SecurityAction.Demand, Unrestricted:=True), SecuritySafeCritical()> _
    Public Sub New(ByVal appName As String, ByVal primaryPurpose As String, ParamArray specificPurpose() As String)
        MyBase.New(appName, primaryPurpose, specificPurpose)

    End Sub
End Class

Poznámky

Tato třída chrání uložená data před zobrazením a manipulací.This class protects stored data from viewing and tampering. Přístup k chráněným datům je získán vytvořením instance této třídy a použitím řetězců s přesným účelem, které byly použity k ochraně dat.The access to the protected data is obtained by creating an instance of this class and using the exact purpose strings that were used to protect the data. Volající nepotřebuje klíč k ochraně nebo odemknutí dat.The caller does not need a key to either protect or unprotect the data. Klíč je poskytován šifrovacím algoritmem.The key is provided by the encryption algorithm.

Odvozené třídy musí přepsat ProviderProtect metody a Unprotect , které DataProtector základní třída volá zpět do.Derived classes must override the ProviderProtect and Unprotect methods, which the DataProtector base class calls back into. Musí také přepsat IsReprotectRequired metodu, která může vždy vracet true s potenciální malou ztrátou efektivity, když aplikace obnoví databázi uložených šifrovaných textů.They must also override the IsReprotectRequired method, which can always return true with a potential small loss of efficiency when applications refresh their database of stored cipher text. Odvozené třídy by měly poskytnout konstruktor, který volá konstruktor základní třídy, který nastavuje ApplicationNamevlastnosti, SpecificPurposesa. PrimaryPurposeDerived classes should provide a constructor that calls the base class constructor, which sets the ApplicationName, SpecificPurposes, and PrimaryPurpose properties.

Konstruktory

DataProtector(String, String, String[]) DataProtector(String, String, String[]) DataProtector(String, String, String[]) DataProtector(String, String, String[])

Vytvoří novou instanci DataProtector třídy pomocí zadaného názvu aplikace, primárního účelu a konkrétních účelů.Creates a new instance of the DataProtector class by using the provided application name, primary purpose, and specific purposes.

Vlastnosti

ApplicationName ApplicationName ApplicationName ApplicationName

Získá název aplikace.Gets the name of the application.

PrependHashedPurposeToPlaintext PrependHashedPurposeToPlaintext PrependHashedPurposeToPlaintext PrependHashedPurposeToPlaintext

Určuje, zda je před šifrováním do textového pole připojen algoritmus hash.Specifies whether the hash is prepended to the text array before encryption.

PrimaryPurpose PrimaryPurpose PrimaryPurpose PrimaryPurpose

Získá primární účel pro chráněná data.Gets the primary purpose for the protected data.

SpecificPurposes SpecificPurposes SpecificPurposes SpecificPurposes

Získá konkrétní účel pro chráněná data.Gets the specific purposes for the protected data.

Metody

Create(String, String, String, String[]) Create(String, String, String, String[]) Create(String, String, String, String[]) Create(String, String, String, String[])

Vytvoří instanci implementace ochrany dat pomocí zadaného názvu třídy ochrany dat, názvu aplikace, primárního účelu a konkrétních účelů.Creates an instance of a data protector implementation by using the specified class name of the data protector, the application name, the primary purpose, and the specific purposes.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Určuje, zda se zadaný objekt rovná aktuálnímu objektu.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Slouží jako výchozí funkce hash.Serves as the default hash function.

(Inherited from Object)
GetHashedPurpose() GetHashedPurpose() GetHashedPurpose() GetHashedPurpose()

Vytvoří hodnotu hash hodnot vlastností určených konstruktorem.Creates a hash of the property values specified by the constructor.

GetType() GetType() GetType() GetType()

Type Získá aktuální instanci.Gets the Type of the current instance.

(Inherited from Object)
IsReprotectRequired(Byte[]) IsReprotectRequired(Byte[]) IsReprotectRequired(Byte[]) IsReprotectRequired(Byte[])

Určuje, zda je pro zadaná šifrovaná data vyžadováno opakované šifrování.Determines if re-encryption is required for the specified encrypted data.

MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Vytvoří kopii aktuálního Objectseznamu.Creates a shallow copy of the current Object.

(Inherited from Object)
Protect(Byte[]) Protect(Byte[]) Protect(Byte[]) Protect(Byte[])

Chrání zadaná uživatelská data.Protects the specified user data.

ProviderProtect(Byte[]) ProviderProtect(Byte[]) ProviderProtect(Byte[]) ProviderProtect(Byte[])

Určuje metodu delegáta v odvozené třídě, kterou Protect(Byte[]) metoda v základní třídě volá zpět do.Specifies the delegate method in the derived class that the Protect(Byte[]) method in the base class calls back into.

ProviderUnprotect(Byte[]) ProviderUnprotect(Byte[]) ProviderUnprotect(Byte[]) ProviderUnprotect(Byte[])

Určuje metodu delegáta v odvozené třídě, kterou Unprotect(Byte[]) metoda v základní třídě volá zpět do.Specifies the delegate method in the derived class that the Unprotect(Byte[]) method in the base class calls back into.

ToString() ToString() ToString() ToString()

Vrací řetězec, který představuje aktuální objekt.Returns a string that represents the current object.

(Inherited from Object)
Unprotect(Byte[]) Unprotect(Byte[]) Unprotect(Byte[]) Unprotect(Byte[])

Odemknout zadaná chráněná data.Unprotects the specified protected data.

Platí pro