PasswordDeriveBytes PasswordDeriveBytes PasswordDeriveBytes PasswordDeriveBytes Class

Definice

Klíč se odvozuje z hesla pomocí rozšíření PBKDF1 algoritmu.Derives a key from a password using an extension of the PBKDF1 algorithm.

public ref class PasswordDeriveBytes : System::Security::Cryptography::DeriveBytes
[System.Runtime.InteropServices.ComVisible(true)]
public class PasswordDeriveBytes : System.Security.Cryptography.DeriveBytes
type PasswordDeriveBytes = class
    inherit DeriveBytes
Public Class PasswordDeriveBytes
Inherits DeriveBytes
Dědičnost
PasswordDeriveBytesPasswordDeriveBytesPasswordDeriveBytesPasswordDeriveBytes
Atributy

Příklady

Následující příklad kódu vytvoří klíč pomocí hesla PasswordDeriveBytes třídy.The following code example creates a key from a password using the PasswordDeriveBytes class.

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

// Generates a random salt value of the specified length.
array<Byte>^ CreateRandomSalt(int length)
{
    // Create a buffer
    array<Byte>^ randomBytes;

    if (length >= 1)
    {
        randomBytes = gcnew array <Byte>(length);
    }
    else
    {
        randomBytes = gcnew array <Byte>(1);
    }

    // Create a new RNGCryptoServiceProvider.
    RNGCryptoServiceProvider^ cryptoRNGProvider =
        gcnew RNGCryptoServiceProvider();

    // Fill the buffer with random bytes.
    cryptoRNGProvider->GetBytes(randomBytes);

    // return the bytes.
    return randomBytes;
}

// Clears the bytes in a buffer so they can't later be read from memory.
void ClearBytes(array<Byte>^ buffer)
{
    // Check arguments.
    if (buffer == nullptr)
    {
        throw gcnew ArgumentNullException("buffer");
    }

    // Set each byte in the buffer to 0.
    for (int x = 0; x <= buffer->Length - 1; x++)
    {
        buffer[x] = 0;
    }
}

int main(array<String^>^ args)
{

    // Get a password from the user.
    Console::WriteLine("Enter a password to produce a key:");

    // Security Note: Never hard-code a password within your
    // source code.  Hard-coded passwords can be retrieved
    // from a compiled assembly.
    array<Byte>^ password = Encoding::Unicode->GetBytes(Console::ReadLine());

    array<Byte>^ randomSalt = CreateRandomSalt(7);

    // Create a TripleDESCryptoServiceProvider object.
    TripleDESCryptoServiceProvider^ cryptoDESProvider =
        gcnew TripleDESCryptoServiceProvider();

    try
    {
        Console::WriteLine("Creating a key with PasswordDeriveBytes...");

        // Create a PasswordDeriveBytes object and then create
        // a TripleDES key from the password and salt.
        PasswordDeriveBytes^ passwordDeriveBytes = gcnew PasswordDeriveBytes
            (password->ToString(), randomSalt);

	   // Create the key and set it to the Key property
	   // of the TripleDESCryptoServiceProvider object.
        cryptoDESProvider->Key = passwordDeriveBytes->CryptDeriveKey
            ("TripleDES", "SHA1", 192, cryptoDESProvider->IV);
        Console::WriteLine("Operation complete.");
    }
    catch (Exception^ ex)
    {
        Console::WriteLine(ex->Message);
    }
    finally
    {
        // Clear the buffers
        ClearBytes(password);
        ClearBytes(randomSalt);

        // Clear the key.
        cryptoDESProvider->Clear();
    }

    Console::ReadLine();
}
using System;
using System.Security.Cryptography;
using System.Text;

public class PasswordDerivedBytesExample
{

    public static void Main(String[] args)
    {

        // Get a password from the user.
        Console.WriteLine("Enter a password to produce a key:");

        byte[] pwd = Encoding.Unicode.GetBytes(Console.ReadLine());

        byte[] salt = CreateRandomSalt(7);

        // Create a TripleDESCryptoServiceProvider object.
        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();

        try
        {
            Console.WriteLine("Creating a key with PasswordDeriveBytes...");

            // Create a PasswordDeriveBytes object and then create
            // a TripleDES key from the password and salt.
            PasswordDeriveBytes pdb = new PasswordDeriveBytes(pwd, salt);


            // Create the key and set it to the Key property
            // of the TripleDESCryptoServiceProvider object.
            tdes.Key = pdb.CryptDeriveKey("TripleDES", "SHA1", 192, tdes.IV);


            Console.WriteLine("Operation complete.");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            // Clear the buffers
            ClearBytes(pwd);
            ClearBytes(salt);

            // Clear the key.
            tdes.Clear();
        }

        Console.ReadLine();
    }

    //////////////////////////////////////////////////////////
    // Helper methods:
    // CreateRandomSalt: Generates a random salt value of the
    //                   specified length.
    //
    // ClearBytes: Clear the bytes in a buffer so they can't
    //             later be read from memory.
    //////////////////////////////////////////////////////////

    public static byte[] CreateRandomSalt(int length)
    {
        // Create a buffer
        byte[] randBytes;

        if (length >= 1)
        {
            randBytes = new byte[length];
        }
        else
        {
            randBytes = new byte[1];
        }

        // Create a new RNGCryptoServiceProvider.
        RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();

        // Fill the buffer with random bytes.
        rand.GetBytes(randBytes);

        // return the bytes.
        return randBytes;
    }

    public static void ClearBytes(byte[] buffer)
    {
        // Check arguments.
        if (buffer == null)
        {
            throw new ArgumentException("buffer");
        }

        // Set each byte in the buffer to 0.
        for (int x = 0; x < buffer.Length; x++)
        {
            buffer[x] = 0;
        }
    }
}
Imports System
Imports System.Security.Cryptography
Imports System.Text



Module PasswordDerivedBytesExample


    Sub Main(ByVal args() As String)

        ' Get a password from the user.
        Console.WriteLine("Enter a password to produce a key:")

        Dim pwd As Byte() = Encoding.Unicode.GetBytes(Console.ReadLine())

        Dim salt As Byte() = CreateRandomSalt(7)

        ' Create a TripleDESCryptoServiceProvider object.
        Dim tdes As New TripleDESCryptoServiceProvider()

        Try
            Console.WriteLine("Creating a key with PasswordDeriveBytes...")

            ' Create a PasswordDeriveBytes object and then create 
            ' a TripleDES key from the password and salt.
            Dim pdb As New PasswordDeriveBytes(pwd, salt)


            ' Create the key and set it to the Key property
            ' of the TripleDESCryptoServiceProvider object.
            tdes.Key = pdb.CryptDeriveKey("TripleDES", "SHA1", 192, tdes.IV)


            Console.WriteLine("Operation complete.")
        Catch e As Exception
            Console.WriteLine(e.Message)
        Finally
            ' Clear the buffers
            ClearBytes(pwd)
            ClearBytes(salt)

            ' Clear the key.
            tdes.Clear()
        End Try

        Console.ReadLine()

    End Sub


    '********************************************************
    '* Helper methods:
    '* createRandomSalt: Generates a random salt value of the 
    '*                   specified length.  
    '*
    '* clearBytes: Clear the bytes in a buffer so they can't 
    '*             later be read from memory.
    '********************************************************
    Function CreateRandomSalt(ByVal length As Integer) As Byte()
        ' Create a buffer
        Dim randBytes() As Byte

        If length >= 1 Then
            randBytes = New Byte(length) {}
        Else
            randBytes = New Byte(0) {}
        End If

        ' Create a new RNGCryptoServiceProvider.
        Dim rand As New RNGCryptoServiceProvider()

        ' Fill the buffer with random bytes.
        rand.GetBytes(randBytes)

        ' return the bytes.
        Return randBytes

    End Function


    Sub ClearBytes(ByVal buffer() As Byte)
        ' Check arguments.
        If buffer Is Nothing Then
            Throw New ArgumentException("buffer")
        End If

        ' Set each byte in the buffer to 0.
        Dim x As Integer
        For x = 0 To buffer.Length - 1
            buffer(x) = 0
        Next x

    End Sub
End Module

Poznámky

Tato třída používá rozšíření algoritmu PBKDF1 definované ve standardní verze 2.0 PKCS č. 5 k odvození bajtů vhodný pro použití jako materiálu klíče z heslo.This class uses an extension of the PBKDF1 algorithm defined in the PKCS#5 v2.0 standard to derive bytes suitable for use as key material from a password. Standard najdete v IETF 2898 kód důvodu registrace.The standard is documented in IETF RRC 2898.

Důležité

Nikdy pevně zakódovat hesla ve zdrojovém kódu.Never hard-code a password within your source code. Pevně zakódované se hesla dají načítat ze sestavení pomocí Ildasm.exe (IL Disassembler) nástroj, šestnáctkový editor, nebo otevřením jednoduše sestavení v textovém editoru, jako je notepad.exe.Hard coded passwords can be retrieved from an assembly using the Ildasm.exe (IL Disassembler) tool, a hex editor, or by simply opening up the assembly in a text editor like notepad.exe.

Konstruktory

PasswordDeriveBytes(Byte[], Byte[]) PasswordDeriveBytes(Byte[], Byte[]) PasswordDeriveBytes(Byte[], Byte[]) PasswordDeriveBytes(Byte[], Byte[])

Inicializuje novou instanci třídy PasswordDeriveBytes třídy zadání hesla a hodnota klíčové salt použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class specifying the password and key salt to use to derive the key.

PasswordDeriveBytes(Byte[], Byte[], CspParameters) PasswordDeriveBytes(Byte[], Byte[], CspParameters) PasswordDeriveBytes(Byte[], Byte[], CspParameters) PasswordDeriveBytes(Byte[], Byte[], CspParameters)

Inicializuje novou instanci třídy PasswordDeriveBytes třídy zadání hesla, salt klíč a zprostředkovatele kryptografických služeb (CSP) použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class specifying the password, key salt, and cryptographic service provider (CSP) to use to derive the key.

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

Inicializuje novou instanci třídy PasswordDeriveBytes třídy zadání hesla, klíčové salt, název hodnoty hash a iterace použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class specifying the password, key salt, hash name, and iterations to use to derive the key.

PasswordDeriveBytes(Byte[], Byte[], String, Int32, CspParameters) PasswordDeriveBytes(Byte[], Byte[], String, Int32, CspParameters) PasswordDeriveBytes(Byte[], Byte[], String, Int32, CspParameters) PasswordDeriveBytes(Byte[], Byte[], String, Int32, CspParameters)

Inicializuje novou instanci třídy PasswordDeriveBytes třídy zadání hesla, klíčové salt, název hodnoty hash, iterací a zprostředkovatele kryptografických služeb (CSP) použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class specifying the password, key salt, hash name, iterations, and cryptographic service provider (CSP) to use to derive the key.

PasswordDeriveBytes(String, Byte[]) PasswordDeriveBytes(String, Byte[]) PasswordDeriveBytes(String, Byte[]) PasswordDeriveBytes(String, Byte[])

Inicializuje novou instanci třídy PasswordDeriveBytes třída s atributem hesla a hodnota klíčové salt použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class with the password and key salt to use to derive the key.

PasswordDeriveBytes(String, Byte[], CspParameters) PasswordDeriveBytes(String, Byte[], CspParameters) PasswordDeriveBytes(String, Byte[], CspParameters) PasswordDeriveBytes(String, Byte[], CspParameters)

Inicializuje novou instanci třídy PasswordDeriveBytes třídy s heslem, salt klíč a CSP provider (CSP) parametry se mají použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class with the password, key salt, and cryptographic service provider (CSP) parameters to use to derive the key.

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

Inicializuje novou instanci třídy PasswordDeriveBytes třídy s heslem, klíčové salt, název hodnoty hash a počet opakování je vyšší použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class with the password, key salt, hash name, and number of iterations to use to derive the key.

PasswordDeriveBytes(String, Byte[], String, Int32, CspParameters) PasswordDeriveBytes(String, Byte[], String, Int32, CspParameters) PasswordDeriveBytes(String, Byte[], String, Int32, CspParameters) PasswordDeriveBytes(String, Byte[], String, Int32, CspParameters)

Inicializuje novou instanci třídy PasswordDeriveBytes třída s atributem heslo, klíčové salt, název hodnoty hash, počet iterací a CSP provider (CSP) parametry se mají použít k odvození klíče.Initializes a new instance of the PasswordDeriveBytes class with the password, key salt, hash name, number of iterations, and cryptographic service provider (CSP) parameters to use to derive the key.

Vlastnosti

HashName HashName HashName HashName

Získá nebo nastaví název algoritmu hash pro tuto operaci.Gets or sets the name of the hash algorithm for the operation.

IterationCount IterationCount IterationCount IterationCount

Získá nebo nastaví počet iterací pro operaci.Gets or sets the number of iterations for the operation.

Salt Salt Salt Salt

Získá nebo nastaví klíčové salt hodnotu pro tuto operaci.Gets or sets the key salt value for the operation.

Metody

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

Je odvozen z kryptografického klíče PasswordDeriveBytes objektu.Derives a cryptographic key from the PasswordDeriveBytes object.

Dispose() Dispose() Dispose() Dispose()

Při přepisu v odvozené třídě, uvolní všechny prostředky používané aktuální instancí třídy DeriveBytes třídy.When overridden in a derived class, releases all resources used by the current instance of the DeriveBytes class.

(Inherited from DeriveBytes)
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)

Uvolní nespravované prostředky využívané třídou PasswordDeriveBytes a volitelně také spravované prostředky.Releases the unmanaged resources used by the PasswordDeriveBytes class and optionally releases the managed resources.

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)
Finalize() Finalize() Finalize() Finalize()

Umožňuje objektu pro pokus o uvolnění prostředků a provádět jiné operace čištění před je uvolněn systémem uvolňování paměti.Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.

GetBytes(Int32) GetBytes(Int32) GetBytes(Int32) GetBytes(Int32)

Vrátí pseudonáhodné klíče bajtů.Returns pseudo-random key bytes.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

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

(Inherited from Object)
GetType() GetType() GetType() GetType()

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

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Vytvoří Mělkou kopii aktuální Object.Creates a shallow copy of the current Object.

(Inherited from Object)
Reset() Reset() Reset() Reset()

Resetuje stav operace.Resets the state of the operation.

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

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

(Inherited from Object)

Platí pro

Viz také