Rfc2898DeriveBytes 类

定义

通过使用基于 HMACSHA1 的伪随机数生成器,实现基于密码的密钥派生功能 (PBKDF2)。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
public 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
继承
Rfc2898DeriveBytes
属性

示例

下面的代码示例使用 Rfc2898DeriveBytes 类为 TripleDES 类创建两个相同的键。The following code example uses the Rfc2898DeriveBytes class to create two identical keys for the TripleDES class. 然后,使用密钥对某些数据进行加密和解密。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

注解

Rfc2898DeriveBytes 获取密码、salt 和迭代次数,然后通过调用 GetBytes 方法来生成密钥。Rfc2898DeriveBytes takes a password, a salt, and an iteration count, and then generates keys through calls to the GetBytes method.

RFC 2898 包含用于从密码和 salt 创建密钥和初始化向量(IV)的方法。RFC 2898 includes methods for creating a key and initialization vector (IV) from a password and salt. 可以使用 PBKDF2,基于密码的密钥派生函数,通过伪随机函数派生密钥,该函数允许生成几乎不受限制的键。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. Rfc2898DeriveBytes 类可用于从基本键和其他参数生成派生密钥。The Rfc2898DeriveBytes class can be used to produce a derived key from a base key and other parameters. 在基于密码的密钥派生函数中,基本密钥是密码,而其他参数是 salt 值和迭代次数。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.

有关 PBKDF2 的详细信息,请参阅征求意见文档网站上的 RFC 2898 "PKCS #5:基于密码的加密规范版本 2.0"。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. 有关完整的详细信息,请参阅5.2 节的 "PBKDF2"。See section 5.2, "PBKDF2," for complete details.

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. 可以通过使用Ildasm (IL 拆装器)、使用十六进制编辑器或只是在文本编辑器(例如 notepad.exe)中打开程序集来检索硬编码的密码。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.

构造函数

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

通过使用密码、salt 值和迭代次数派生密钥,初始化 Rfc2898DeriveBytes 类的新实例。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)

初始化 Rfc2898DeriveBytes 类的新实例,该实例使用指定的密码、salt、迭代数和哈希算法名称来派生密钥。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[])

通过使用密码和 salt 值派生密钥,初始化 Rfc2898DeriveBytes 类的新实例。Initializes a new instance of the Rfc2898DeriveBytes class using a password and salt to derive the key.

Rfc2898DeriveBytes(String, Byte[], Int32)

通过使用密码、salt 值和迭代次数派生密钥,初始化 Rfc2898DeriveBytes 类的新实例。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)

初始化 Rfc2898DeriveBytes 类的新实例,该实例使用指定的密码、salt、迭代数和哈希算法名称来派生密钥。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)

通过使用密码和 salt 大小派生密钥,初始化 Rfc2898DeriveBytes 类的新实例。Initializes a new instance of the Rfc2898DeriveBytes class using the password and salt size to derive the key.

Rfc2898DeriveBytes(String, Int32, Int32)

通过使用密码、salt 值和迭代次数派生密钥,初始化 Rfc2898DeriveBytes 类的新实例。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)

初始化 Rfc2898DeriveBytes 类的新实例,该实例使用指定的密码、salt 大小、迭代数和哈希算法名称来派生密钥。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.

属性

HashAlgorithm
IterationCount

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

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[])

Rfc2898DeriveBytes 对象导出加密密钥。Derives a cryptographic key from the Rfc2898DeriveBytes object.

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.

(继承自 DeriveBytes)
Dispose(Boolean)

释放 Rfc2898DeriveBytes 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 Rfc2898DeriveBytes class and optionally releases the managed resources.

Dispose(Boolean)

在派生类中重写时,释放由 DeriveBytes 类占用的非托管资源,还可以另外再释放托管资源。When overridden in a derived class, releases the unmanaged resources used by the DeriveBytes class and optionally releases the managed resources.

(继承自 DeriveBytes)
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.

(继承自 Object)
GetBytes(Int32)

返回此对象的伪随机密钥。Returns the pseudo-random key for this object.

GetHashCode()

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

(继承自 Object)
GetType()

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

(继承自 Object)
MemberwiseClone()

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

(继承自 Object)
Reset()

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

ToString()

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

(继承自 Object)

适用于

另请参阅