PasswordDeriveBytes PasswordDeriveBytes PasswordDeriveBytes PasswordDeriveBytes Class

定义

使用 PBKDF1 算法的扩展从密码派生密钥。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
继承
PasswordDeriveBytesPasswordDeriveBytesPasswordDeriveBytesPasswordDeriveBytes
属性

示例

下面的代码示例使用PasswordDeriveBytes类从密码创建密钥。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.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

注解

此类使用 PKCS # 5 v2.0 标准版中定义的 PBKDF1 算法的扩展从密码派生适合用作密钥材料的字节。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. IETF RRC 2898 中记录了标准。The standard is documented in IETF RRC 2898.

重要

不要在源代码中对密码进行硬编码。Never hard-code a password within your source code. 使用Ildasm (IL 拆装器)工具、十六进制编辑器或只是在文本编辑器 (例如 notepad.exe) 中打开程序集, 可以从程序集检索硬编码的密码。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.

构造函数

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

通过指定用来派生密钥的密码和密钥 salt 初始化 PasswordDeriveBytes 类的新实例。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)

通过指定用来派生密钥的密码、密钥 salt 和加密服务提供程序 (CSP) 初始化 PasswordDeriveBytes 类的新实例。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)

通过指定用来派生密钥的密码、密钥 salt、哈希名和迭代数初始化 PasswordDeriveBytes 类的新实例。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)

通过指定用来派生密钥的密码、密钥 salt、哈希名、迭代数和加密服务提供程序 (CSP) 初始化 PasswordDeriveBytes 类的新实例。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[])

使用用来导出密钥的密码和密钥 salt 初始化 PasswordDeriveBytes 类的新实例。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)

使用用来导出密钥的密码、密钥 salt 和加密服务提供程序 (CSP) 参数初始化 PasswordDeriveBytes 类的新实例。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)

使用用来导出密钥的密码、密钥 salt、哈希名和迭代数初始化 PasswordDeriveBytes 类的新实例。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)

使用用来导出密钥的密码、密钥 salt、哈希名、迭代数和加密服务提供程序 (CSP) 参数初始化 PasswordDeriveBytes 类的新实例。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.

属性

HashName HashName HashName HashName

获取或设置操作的哈希算法的名称。Gets or sets the name of the hash algorithm for the operation.

IterationCount IterationCount IterationCount IterationCount

获取或设置操作的迭代数。Gets or sets the number of iterations for the operation.

Salt Salt Salt Salt

获取或设置操作的密钥 salt 值。Gets or sets the key salt value for the operation.

方法

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

PasswordDeriveBytes 对象导出加密密钥。Derives a cryptographic key from the PasswordDeriveBytes object.

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

在派生类中重写时,释放由 DeriveBytes 类的当前实例使用的所有资源。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)

释放 PasswordDeriveBytes 类使用的非托管资源,并可以选择释放托管资源。Releases the unmanaged resources used by the PasswordDeriveBytes class and optionally releases the managed resources.

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

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(Inherited from Object)
Finalize() Finalize() Finalize() Finalize()

在垃圾回收将某一对象回收前允许该对象尝试释放资源并执行其他清理操作。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)

返回伪随机密钥字节。Returns pseudo-random key bytes.

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

作为默认哈希函数。Serves as the default hash function.

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

获取当前实例的 TypeGets the Type of the current instance.

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

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

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

重置操作的状态。Resets the state of the operation.

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

返回表示当前对象的字符串。Returns a string that represents the current object.

(Inherited from Object)

适用于

另请参阅