Rfc2898DeriveBytes Clase

Definición

Implementa PBKDF2 (función de derivación de claves basada en contraseña) utilizando un generador de números pseudoaleatorios basado en HMACSHA1.Implements password-based key derivation functionality, PBKDF2, by using a pseudo-random number generator based on HMACSHA1.

public ref class Rfc2898DeriveBytes : System::Security::Cryptography::DeriveBytes
[System.Runtime.InteropServices.ComVisible(true)]
public class Rfc2898DeriveBytes : System.Security.Cryptography.DeriveBytes
type Rfc2898DeriveBytes = class
    inherit DeriveBytes
Public Class Rfc2898DeriveBytes
Inherits DeriveBytes
Herencia
Rfc2898DeriveBytes
Atributos

Ejemplos

En el ejemplo de código siguiente Rfc2898DeriveBytes se usa la clase para crear dos claves TripleDES idénticas para la clase.The following code example uses the Rfc2898DeriveBytes class to create two identical keys for the TripleDES class. A continuación, cifra y descifra algunos datos mediante las claves.It then encrypts and decrypts some data using the keys.

using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Security::Cryptography;

// Generate a key k1 with password pwd1 and salt salt1.
// Generate a key k2 with password pwd1 and salt salt1.
// Encrypt data1 with key k1 using symmetric encryption, creating edata1.
// Decrypt edata1 with key k2 using symmetric decryption, creating data2.
// data2 should equal data1.

int main()
{
   array<String^>^passwordargs = Environment::GetCommandLineArgs();
   String^ usageText = "Usage: RFC2898 <password>\nYou must specify the password for encryption.\n";

   //If no file name is specified, write usage text.
   if ( passwordargs->Length == 1 )
   {
      Console::WriteLine( usageText );
   }
   else
   {
      String^ pwd1 = passwordargs[ 1 ];
      
      array<Byte>^salt1 = gcnew array<Byte>(8);
      RNGCryptoServiceProvider ^ rngCsp = gcnew RNGCryptoServiceProvider();
         rngCsp->GetBytes(salt1);
      //data1 can be a string or contents of a file.
      String^ data1 = "Some test data";

      //The default iteration count is 1000 so the two methods use the same iteration count.
      int myIterations = 1000;

      try
      {
         Rfc2898DeriveBytes ^ k1 = gcnew Rfc2898DeriveBytes( pwd1,salt1,myIterations );
         Rfc2898DeriveBytes ^ k2 = gcnew Rfc2898DeriveBytes( pwd1,salt1 );

         // Encrypt the data.
         TripleDES^ encAlg = TripleDES::Create();
         encAlg->Key = k1->GetBytes( 16 );
         MemoryStream^ encryptionStream = gcnew MemoryStream;
         CryptoStream^ encrypt = gcnew CryptoStream( encryptionStream,encAlg->CreateEncryptor(),CryptoStreamMode::Write );
         array<Byte>^utfD1 = (gcnew System::Text::UTF8Encoding( false ))->GetBytes( data1 );

         encrypt->Write( utfD1, 0, utfD1->Length );
         encrypt->FlushFinalBlock();
         encrypt->Close();
         array<Byte>^edata1 = encryptionStream->ToArray();
         k1->Reset();

         // Try to decrypt, thus showing it can be round-tripped.
         TripleDES^ decAlg = TripleDES::Create();
         decAlg->Key = k2->GetBytes( 16 );
         decAlg->IV = encAlg->IV;
         MemoryStream^ decryptionStreamBacking = gcnew MemoryStream;
         CryptoStream^ decrypt = gcnew CryptoStream( decryptionStreamBacking,decAlg->CreateDecryptor(),CryptoStreamMode::Write );

         decrypt->Write( edata1, 0, edata1->Length );
         decrypt->Flush();
         decrypt->Close();
         k2->Reset();

         String^ data2 = (gcnew UTF8Encoding( false ))->GetString( decryptionStreamBacking->ToArray() );
         if (  !data1->Equals( data2 ) )
         {
            Console::WriteLine( "Error: The two values are not equal." );
         }
         else
         {
            Console::WriteLine( "The two values are equal." );
            Console::WriteLine( "k1 iterations: {0}", k1->IterationCount );
            Console::WriteLine( "k2 iterations: {0}", k2->IterationCount );
         }
      }

      catch ( Exception^ e ) 
      {
         Console::WriteLine( "Error: ", e );
      }
   }
}
using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

public class rfc2898test
{
    // Generate a key k1 with password pwd1 and salt salt1.
    // Generate a key k2 with password pwd1 and salt salt1.
    // Encrypt data1 with key k1 using symmetric encryption, creating edata1.
    // Decrypt edata1 with key k2 using symmetric decryption, creating data2.
    // data2 should equal data1.

    private const string usageText = "Usage: RFC2898 <password>\nYou must 
specify the password for encryption.\n";
    public static void Main(string[] passwordargs)
    {
        //If no file name is specified, write usage text.
        if (passwordargs.Length == 0)
        {
            Console.WriteLine(usageText);
        }
        else
        {
            string pwd1 = passwordargs[0];
            // Create a byte array to hold the random value. 
            byte[] salt1 = new byte[8];
            using (RNGCryptoServiceProvider rngCsp = new 
RNGCryptoServiceProvider())
            {
                // Fill the array with a random value.
                rngCsp.GetBytes(salt1);
            }

            //data1 can be a string or contents of a file.
            string data1 = "Some test data";
            //The default iteration count is 1000 so the two methods use the 
same iteration count.
            int myIterations = 1000;
            try
            {
                Rfc2898DeriveBytes k1 = new Rfc2898DeriveBytes(pwd1, salt1, 
myIterations);
                Rfc2898DeriveBytes k2 = new Rfc2898DeriveBytes(pwd1, salt1);
                // Encrypt the data.
                TripleDES encAlg = TripleDES.Create();
                encAlg.Key = k1.GetBytes(16);
                MemoryStream encryptionStream = new MemoryStream();
                CryptoStream encrypt = new CryptoStream(encryptionStream, 
encAlg.CreateEncryptor(), CryptoStreamMode.Write);
                byte[] utfD1 = new System.Text.UTF8Encoding(false).GetBytes(
data1);

                encrypt.Write(utfD1, 0, utfD1.Length);
                encrypt.FlushFinalBlock();
                encrypt.Close();
                byte[] edata1 = encryptionStream.ToArray();
                k1.Reset();

                // Try to decrypt, thus showing it can be round-tripped.
                TripleDES decAlg = TripleDES.Create();
                decAlg.Key = k2.GetBytes(16);
                decAlg.IV = encAlg.IV;
                MemoryStream decryptionStreamBacking = new MemoryStream();
                CryptoStream decrypt = new CryptoStream(
decryptionStreamBacking, decAlg.CreateDecryptor(), CryptoStreamMode.Write);
                decrypt.Write(edata1, 0, edata1.Length);
                decrypt.Flush();
                decrypt.Close();
                k2.Reset();
                string data2 = new UTF8Encoding(false).GetString(
decryptionStreamBacking.ToArray());

                if (!data1.Equals(data2))
                {
                    Console.WriteLine("Error: The two values are not equal.");
                }
                else
                {
                    Console.WriteLine("The two values are equal.");
                    Console.WriteLine("k1 iterations: {0}", k1.IterationCount);
                    Console.WriteLine("k2 iterations: {0}", k2.IterationCount);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("Error: ", e);
            }

        }
    }
}
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography



Public Class rfc2898test
    ' Generate a key k1 with password pwd1 and salt salt1.
    ' Generate a key k2 with password pwd1 and salt salt1.
    ' Encrypt data1 with key k1 using symmetric encryption, creating edata1.
    ' Decrypt edata1 with key k2 using symmetric decryption, creating data2.
    ' data2 should equal data1.
    Private Const usageText As String = "Usage: RFC2898 <password>" + vbLf + "You must specify the password for encryption." + vbLf

    Public Shared Sub Main(ByVal passwordargs() As String)
        'If no file name is specified, write usage text.
        If passwordargs.Length = 0 Then
            Console.WriteLine(usageText)
        Else
            Dim pwd1 As String = passwordargs(0)

            Dim salt1(8) As Byte
            Using rngCsp As New RNGCryptoServiceProvider()
                rngCsp.GetBytes(salt1)
            End Using
            'data1 can be a string or contents of a file.
            Dim data1 As String = "Some test data"
            'The default iteration count is 1000 so the two methods use the same iteration count.
            Dim myIterations As Integer = 1000
            Try
                Dim k1 As New Rfc2898DeriveBytes(pwd1, salt1, myIterations)
                Dim k2 As New Rfc2898DeriveBytes(pwd1, salt1)
                ' Encrypt the data.
                Dim encAlg As TripleDES = TripleDES.Create()
                encAlg.Key = k1.GetBytes(16)
                Dim encryptionStream As New MemoryStream()
                Dim encrypt As New CryptoStream(encryptionStream, encAlg.CreateEncryptor(), CryptoStreamMode.Write)
                Dim utfD1 As Byte() = New System.Text.UTF8Encoding(False).GetBytes(data1)
                encrypt.Write(utfD1, 0, utfD1.Length)
                encrypt.FlushFinalBlock()
                encrypt.Close()
                Dim edata1 As Byte() = encryptionStream.ToArray()
                k1.Reset()

                ' Try to decrypt, thus showing it can be round-tripped.
                Dim decAlg As TripleDES = TripleDES.Create()
                decAlg.Key = k2.GetBytes(16)
                decAlg.IV = encAlg.IV
                Dim decryptionStreamBacking As New MemoryStream()
                Dim decrypt As New CryptoStream(decryptionStreamBacking, decAlg.CreateDecryptor(), CryptoStreamMode.Write)
                decrypt.Write(edata1, 0, edata1.Length)
                decrypt.Flush()
                decrypt.Close()
                k2.Reset()
                Dim data2 As String = New UTF8Encoding(False).GetString(decryptionStreamBacking.ToArray())

                If Not data1.Equals(data2) Then
                    Console.WriteLine("Error: The two values are not equal.")
                Else
                    Console.WriteLine("The two values are equal.")
                    Console.WriteLine("k1 iterations: {0}", k1.IterationCount)
                    Console.WriteLine("k2 iterations: {0}", k2.IterationCount)
                End If
            Catch e As Exception
                Console.WriteLine("Error: ", e)
            End Try
        End If

    End Sub
End Class

Comentarios

Rfc2898DeriveBytestoma una contraseña, un valor Salt y un recuento de iteraciones y, a continuación, genera GetBytes claves a través de llamadas al método.Rfc2898DeriveBytes takes a password, a salt, and an iteration count, and then generates keys through calls to the GetBytes method.

RFC 2898 incluye métodos para crear una clave y un vector de inicialización (IV) a partir de una contraseña y un valor Salt.RFC 2898 includes methods for creating a key and initialization vector (IV) from a password and salt. Puede usar PBKDF2, una función de derivación de claves basada en contraseña, para derivar claves mediante una función pseudoaleatorios que permita que se generen claves de longitud prácticamente ilimitada.You can use PBKDF2, a password-based key derivation function, to derive keys using a pseudo-random function that allows keys of virtually unlimited length to be generated. La Rfc2898DeriveBytes clase se puede utilizar para generar una clave derivada a partir de una clave base y otros parámetros.The Rfc2898DeriveBytes class can be used to produce a derived key from a base key and other parameters. En una función de derivación de claves basada en contraseña, la clave base es una contraseña y los demás parámetros son un valor Salt y un número de iteraciones.In a password-based key derivation function, the base key is a password and the other parameters are a salt value and an iteration count.

Para obtener más información sobre PBKDF2, consulte RFC 2898, "PKCS #5: Versión 2,0 de la especificación de criptografía basada en contraseña, disponible en el sitio web de solicitud de comentarios.For more information about PBKDF2, see RFC 2898, "PKCS #5: Password-Based Cryptography Specification Version 2.0," available on the Request for Comments Web site. Vea la sección 5,2, "PBKDF2", para obtener detalles completos.See section 5.2, "PBKDF2," for complete details.

Importante

No codifique nunca una contraseña dentro del código fuente.Never hard-code a password within your source code. Las contraseñas codificadas de forma rígida se pueden recuperar de un ensamblado mediante Ildasm. exe (desensamblador de IL), mediante un editor hexadecimal, o simplemente abriendo el ensamblado en un editor de texto, como Notepad. exe.Hard-coded passwords can be retrieved from an assembly by using the Ildasm.exe (IL Disassembler), by using a hexadecimal editor, or by simply opening up the assembly in a text editor such as Notepad.exe.

Constructores

Rfc2898DeriveBytes(Byte[], Byte[], Int32)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes utilizando una contraseña, un valor salt y un número de iteraciones para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using a password, a salt, and number of iterations to derive the key.

Rfc2898DeriveBytes(Byte[], Byte[], Int32, HashAlgorithmName)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes mediante la contraseña, el valor "salt", el número de iteraciones y el nombre del algoritmo hash especificados para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using the specified password, salt, number of iterations and the hash algorithm name to derive the key.

Rfc2898DeriveBytes(String, Byte[])

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes utilizando una contraseña y un valor salt para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using a password and salt to derive the key.

Rfc2898DeriveBytes(String, Byte[], Int32)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes utilizando una contraseña, un valor salt y un número de iteraciones para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using a password, a salt, and number of iterations to derive the key.

Rfc2898DeriveBytes(String, Byte[], Int32, HashAlgorithmName)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes mediante la contraseña, el valor "salt", el número de iteraciones y el nombre del algoritmo hash especificados para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using the specified password, salt, number of iterations and the hash algorithm name to derive the key.

Rfc2898DeriveBytes(String, Int32)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes utilizando la contraseña y el tamaño del valor salt para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using the password and salt size to derive the key.

Rfc2898DeriveBytes(String, Int32, Int32)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes utilizando una contraseña, un tamaño de valor salt y un número de iteraciones para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using a password, a salt size, and number of iterations to derive the key.

Rfc2898DeriveBytes(String, Int32, Int32, HashAlgorithmName)

Inicializa una nueva instancia de la clase Rfc2898DeriveBytes mediante la contraseña, el tamaño del valor "salt", el número de iteraciones y el nombre del algoritmo hash especificados para derivar la clave.Initializes a new instance of the Rfc2898DeriveBytes class using the specified password, salt size, number of iterations and the hash algorithm name to derive the key.

Propiedades

HashAlgorithm
IterationCount

Obtiene o establece el número de iteraciones de la operación.Gets or sets the number of iterations for the operation.

Salt

Obtiene o establece el valor salt de clave de la operación.Gets or sets the key salt value for the operation.

Métodos

CryptDeriveKey(String, String, Int32, Byte[])

Deriva una clave criptográfica a partir del objeto Rfc2898DeriveBytes.Derives a cryptographic key from the Rfc2898DeriveBytes object.

Dispose()

Cuando se reemplaza en una clase derivada, libera todos los recursos usados por la instancia actual de la clase DeriveBytes.When overridden in a derived class, releases all resources used by the current instance of the DeriveBytes class.

(Heredado de DeriveBytes)
Dispose(Boolean)

Libera los recursos no administrados utilizados por la clase Rfc2898DeriveBytes y, de forma opcional, libera los recursos administrados.Releases the unmanaged resources used by the Rfc2898DeriveBytes class and optionally releases the managed resources.

Equals(Object)

Determina si el objeto especificado es igual al objeto actual.Determines whether the specified object is equal to the current object.

(Heredado de Object)
GetBytes(Int32)

Devuelve la clave pseudoaleatoria para este objeto.Returns the pseudo-random key for this object.

GetHashCode()

Sirve como función hash predeterminada.Serves as the default hash function.

(Heredado de Object)
GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Heredado de Object)
MemberwiseClone()

Crea una copia superficial del Object actual.Creates a shallow copy of the current Object.

(Heredado de Object)
Reset()

Restablece el estado de la operación.Resets the state of the operation.

ToString()

Devuelve un valor de tipo string que representa el objeto actual.Returns a string that represents the current object.

(Heredado de Object)

Se aplica a

Consulte también: