SHA256Managed 类

定义

注意

Derived cryptographic types are obsolete. Use the Create method on the base type instead.

使用托管库计算输入数据的 SHA256 哈希值。

public ref class SHA256Managed sealed : System::Security::Cryptography::SHA256
public ref class SHA256Managed : System::Security::Cryptography::SHA256
public sealed class SHA256Managed : System.Security.Cryptography.SHA256
[System.Obsolete("Derived cryptographic types are obsolete. Use the Create method on the base type instead.", DiagnosticId="SYSLIB0021", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public sealed class SHA256Managed : System.Security.Cryptography.SHA256
public class SHA256Managed : System.Security.Cryptography.SHA256
[System.Runtime.InteropServices.ComVisible(true)]
public class SHA256Managed : System.Security.Cryptography.SHA256
type SHA256Managed = class
    inherit SHA256
[<System.Obsolete("Derived cryptographic types are obsolete. Use the Create method on the base type instead.", DiagnosticId="SYSLIB0021", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type SHA256Managed = class
    inherit SHA256
[<System.Runtime.InteropServices.ComVisible(true)>]
type SHA256Managed = class
    inherit SHA256
Public NotInheritable Class SHA256Managed
Inherits SHA256
Public Class SHA256Managed
Inherits SHA256
继承
SHA256Managed
属性

示例

以下示例计算目录中所有文件的 SHA-256 哈希。

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

// Print the byte array in a readable format.
void PrintByteArray( array<Byte>^array )
{
   int i;
   for ( i = 0; i < array->Length; i++ )
   {
      Console::Write( String::Format( "{0:X2}", array[ i ] ) );
      if ( (i % 4) == 3 )
            Console::Write( " " );

   }
   Console::WriteLine();
}

int main()
{
   array<String^>^args = Environment::GetCommandLineArgs();
   if ( args->Length < 2 )
   {
      Console::WriteLine( "Usage: hashdir <directory>" );
      return 0;
   }

   try
   {

      // Create a DirectoryInfo object representing the specified directory.
      DirectoryInfo^ dir = gcnew DirectoryInfo( args[ 1 ] );

      // Get the FileInfo objects for every file in the directory.
      array<FileInfo^>^files = dir->GetFiles();

      // Initialize a SHA256 hash object.
      SHA256 ^ mySHA256 = SHA256Managed::Create();
      array<Byte>^hashValue;

      // Compute and print the hash values for each file in directory.
      System::Collections::IEnumerator^ myEnum = files->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         FileInfo^ fInfo = safe_cast<FileInfo^>(myEnum->Current);

         // Create a fileStream for the file.
         FileStream^ fileStream = fInfo->Open( FileMode::Open );

         // Compute the hash of the fileStream.
         hashValue = mySHA256->ComputeHash( fileStream );

         // Write the name of the file to the Console.
         Console::Write( "{0}: ", fInfo->Name );

         // Write the hash value to the Console.
         PrintByteArray( hashValue );

         // Close the file.
         fileStream->Close();
      }
      return 0;
   }
   catch ( DirectoryNotFoundException^ ) 
   {
      Console::WriteLine( "Error: The directory specified could not be found." );
   }
   catch ( IOException^ ) 
   {
      Console::WriteLine( "Error: A file in the directory could not be accessed." );
   }

}
using System;
using System.IO;
using System.Security.Cryptography;

public class HashDirectory
{
    public static void Main(string[] args)
    {
        if (args.Length < 1)
        {
            Console.WriteLine("No directory selected.");
            return;
        }

        string directory = args[0];
        if (Directory.Exists(directory))
        {
            // Create a DirectoryInfo object representing the specified directory.
            var dir = new DirectoryInfo(directory);
            // Get the FileInfo objects for every file in the directory.
            FileInfo[] files = dir.GetFiles();
            // Initialize a SHA256 hash object.
            using (SHA256 mySHA256 = SHA256.Create())
            {
                // Compute and print the hash values for each file in directory.
                foreach (FileInfo fInfo in files)
                {
                    using (FileStream fileStream = fInfo.Open(FileMode.Open))
                    {
                        try
                        {
                            // Create a fileStream for the file.
                            // Be sure it's positioned to the beginning of the stream.
                            fileStream.Position = 0;
                            // Compute the hash of the fileStream.
                            byte[] hashValue = mySHA256.ComputeHash(fileStream);
                            // Write the name and hash value of the file to the console.
                            Console.Write($"{fInfo.Name}: ");
                            PrintByteArray(hashValue);
                        }
                        catch (IOException e)
                        {
                            Console.WriteLine($"I/O Exception: {e.Message}");
                        }
                        catch (UnauthorizedAccessException e)
                        {
                            Console.WriteLine($"Access Exception: {e.Message}");
                        }
                    }
                }
            }
        }
        else
        {
            Console.WriteLine("The directory specified could not be found.");
        }
    }

    // Display the byte array in a readable format.
    public static void PrintByteArray(byte[] array)
    {
        for (int i = 0; i < array.Length; i++)
        {
            Console.Write($"{array[i]:X2}");
            if ((i % 4) == 3) Console.Write(" ");
        }
        Console.WriteLine();
    }
}
Imports System.IO
Imports System.Security.Cryptography

Public Module HashDirectory

    Public Sub Main(ByVal args() As String)
        If args.Length < 1 Then
            Console.WriteLine("No directory selected")
            Return
        End If

        Dim targetDirectory As String = args(0)
        If Directory.Exists(targetDirectory) Then
            ' Create a DirectoryInfo object representing the specified directory.
            Dim dir As New DirectoryInfo(targetDirectory)
            ' Get the FileInfo objects for every file in the directory.
            Dim files As FileInfo() = dir.GetFiles()
            ' Initialize a SHA256 hash object.
            Using mySHA256 As SHA256 = SHA256.Create()
                ' Compute and print the hash values for each file in directory.
                For Each fInfo  As FileInfo In files
                    Try
                        ' Create a fileStream for the file.
                        Dim fileStream = fInfo.Open(FileMode.Open)
                        ' Be sure it's positioned to the beginning of the stream.
                        fileStream.Position = 0
                        ' Compute the hash of the fileStream.
                        Dim hashValue() As Byte = mySHA256.ComputeHash(fileStream)
                        ' Write the name of the file to the Console.
                        Console.Write(fInfo.Name + ": ")
                        ' Write the hash value to the Console.
                        PrintByteArray(hashValue)
                        ' Close the file.
                        fileStream.Close()
                    Catch e As IOException
                        Console.WriteLine($"I/O Exception: {e.Message}")
                    Catch e As UnauthorizedAccessException 
                        Console.WriteLine($"Access Exception: {e.Message}")
                    End Try    
                Next 
            End Using
        Else
           Console.WriteLine("The directory specified could not be found.")
        End If
    End Sub

    ' Print the byte array in a readable format.
    Public Sub PrintByteArray(array() As Byte)
        For i As Integer = 0 To array.Length - 1
            Console.Write($"{array(i):X2}")
            If i Mod 4 = 3 Then
                Console.Write(" ")
            End If
        Next 
        Console.WriteLine()

    End Sub 
End Module

注解

哈希用作表示大量数据的固定大小的唯一值。 当并且仅当相应数据也匹配时,两组数据的哈希应匹配。 对数据的小更改会导致哈希中出现大量不可预知的更改。

算法的 SHA256Managed 哈希大小为 256 位。

构造函数

SHA256Managed()
已过时.

使用托管库初始化 SHA256Managed 类的新实例。

字段

HashSizeInBits
已过时.

SHA256 算法生成的哈希大小(以位为单位)。

(继承自 SHA256)
HashSizeInBytes
已过时.

SHA256 算法生成的哈希大小(以字节为单位)。

(继承自 SHA256)
HashSizeValue
已过时.

表示计算所得的哈希代码的大小(以位为单位)。

(继承自 HashAlgorithm)
HashValue
已过时.

表示计算所得的哈希代码的值。

(继承自 HashAlgorithm)
State
已过时.

表示哈希计算的状态。

(继承自 HashAlgorithm)

属性

CanReuseTransform
已过时.

获取一个值,该值指示是否可重复使用当前转换。

(继承自 HashAlgorithm)
CanTransformMultipleBlocks
已过时.

当在派生类中重写时,获取一个值,该值指示是否可以转换多个块。

(继承自 HashAlgorithm)
Hash
已过时.

获取计算所得的哈希代码的值。

(继承自 HashAlgorithm)
HashSize
已过时.

获取计算所得的哈希代码的大小(以位为单位)。

(继承自 HashAlgorithm)
InputBlockSize
已过时.

当在派生类中重写时,获取输入块的大小。

(继承自 HashAlgorithm)
OutputBlockSize
已过时.

当在派生类中重写时,获取输出块的大小。

(继承自 HashAlgorithm)

方法

Clear()
已过时.

释放 HashAlgorithm 类使用的所有资源。

(继承自 HashAlgorithm)
ComputeHash(Byte[])
已过时.

计算指定字节数组的哈希值。

(继承自 HashAlgorithm)
ComputeHash(Byte[], Int32, Int32)
已过时.

计算指定字节数组的指定区域的哈希值。

(继承自 HashAlgorithm)
ComputeHash(Stream)
已过时.

计算指定 Stream 对象的哈希值。

(继承自 HashAlgorithm)
ComputeHashAsync(Stream, CancellationToken)
已过时.

异步计算指定 Stream 对象的哈希值。

(继承自 HashAlgorithm)
Dispose()
已过时.

释放 HashAlgorithm 类的当前实例所使用的所有资源。

(继承自 HashAlgorithm)
Dispose(Boolean)
已过时.

释放由 SHA256Managed 对象使用的非托管资源并(可选)释放托管资源。

Dispose(Boolean)
已过时.

释放由 HashAlgorithm 占用的非托管资源,还可以另外再释放托管资源。

(继承自 HashAlgorithm)
Equals(Object)
已过时.

确定指定对象是否等于当前对象。

(继承自 Object)
GetHashCode()
已过时.

作为默认哈希函数。

(继承自 Object)
GetType()
已过时.

获取当前实例的 Type

(继承自 Object)
HashCore(Byte[], Int32, Int32)
已过时.

当在派生类中重写时,将写入对象的数据路由到 SHA256 哈希算法以计算哈希值。

HashCore(Byte[], Int32, Int32)
已过时.

当在派生类中重写时,将写入对象的数据路由到哈希算法以计算哈希值。

(继承自 HashAlgorithm)
HashCore(ReadOnlySpan<Byte>)
已过时.

将写入对象的数据路由到哈希算法以计算哈希值。

(继承自 HashAlgorithm)
HashFinal()
已过时.

当在派生类中重写时,在加密流对象处理完最后的数据后完成哈希计算。

HashFinal()
已过时.

在派生类中重写时,在加密哈希算法处理最后一个数据后结束哈希计算。

(继承自 HashAlgorithm)
Initialize()
已过时.

初始化 SHA256Managed 的实例。

MemberwiseClone()
已过时.

创建当前 Object 的浅表副本。

(继承自 Object)
ToString()
已过时.

返回表示当前对象的字符串。

(继承自 Object)
TransformBlock(Byte[], Int32, Int32, Byte[], Int32)
已过时.

计算输入字节数组指定区域的哈希值,并将输入字节数组指定区域复制到输出字节数组的指定区域。

(继承自 HashAlgorithm)
TransformFinalBlock(Byte[], Int32, Int32)
已过时.

计算指定字节数组的指定区域的哈希值。

(继承自 HashAlgorithm)
TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32)
已过时.

尝试计算指定字节数组的哈希值。

(继承自 HashAlgorithm)
TryHashFinal(Span<Byte>, Int32)
已过时.

在哈希算法处理最后一个数据后,尝试结束哈希计算。

(继承自 HashAlgorithm)

显式接口实现

IDisposable.Dispose()
已过时.

释放由 HashAlgorithm 占用的非托管资源,还可以另外再释放托管资源。

(继承自 HashAlgorithm)

适用于

另请参阅