SHA256Managed SHA256Managed SHA256Managed SHA256Managed Class

定义

使用托管库计算输入数据的 SHA256 哈希值。Computes the SHA256 hash for the input data using the managed library.

public ref class SHA256Managed : System::Security::Cryptography::SHA256
[System.Runtime.InteropServices.ComVisible(true)]
public class SHA256Managed : System.Security.Cryptography.SHA256
type SHA256Managed = class
    inherit SHA256
Public Class SHA256Managed
Inherits SHA256
继承
属性

示例

下面的示例计算目录中所有文件的 SHA-256 哈希。The following example calculates the SHA-256 hash for all files in a directory.

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)
                {
                    try { 
                        // Create a fileStream for the file.
                        FileStream 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.
                        byte[] hashValue = mySHA256.ComputeHash(fileStream);
                        // Write the name and hash value of the file to the console.
                        Console.Write($"{fInfo.Name}: ");
                        PrintByteArray(hashValue);
                        // Close the file.
                        fileStream.Close();
                    }
                    catch (IOException e) {
                        Console.WriteLine($"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

哈希值用作表示大量数据的固定大小的唯一值。The hash is used as a unique value of fixed size representing a large amount of data. 当且仅当相应的数据也匹配时,两组数据的哈希才会匹配。Hashes of two sets of data should match if and only if the corresponding data also matches. 对数据的小更改会导致哈希中的大量无法预测的更改。Small changes to the data result in large unpredictable changes in the hash.

SHA256Managed算法的哈希大小为256位。The hash size for the SHA256Managed algorithm is 256 bits.

构造函数

SHA256Managed() SHA256Managed() SHA256Managed() SHA256Managed()

使用托管库初始化 SHA256Managed 类的新实例。Initializes a new instance of the SHA256Managed class using the managed library.

方法

Clear() Clear() Clear() Clear()

释放 HashAlgorithm 类使用的所有资源。Releases all resources used by the HashAlgorithm class.

(Inherited from HashAlgorithm)
ComputeHash(Byte[]) ComputeHash(Byte[]) ComputeHash(Byte[]) ComputeHash(Byte[])

计算指定字节数组的哈希值。Computes the hash value for the specified byte array.

(Inherited from HashAlgorithm)
ComputeHash(Byte[], Int32, Int32) ComputeHash(Byte[], Int32, Int32) ComputeHash(Byte[], Int32, Int32) ComputeHash(Byte[], Int32, Int32)

计算指定字节数组的指定区域的哈希值。Computes the hash value for the specified region of the specified byte array.

(Inherited from HashAlgorithm)
ComputeHash(Stream) ComputeHash(Stream) ComputeHash(Stream) ComputeHash(Stream)

计算指定 Stream 对象的哈希值。Computes the hash value for the specified Stream object.

(Inherited from HashAlgorithm)
Dispose() Dispose() Dispose() Dispose()

释放 HashAlgorithm 类的当前实例所使用的所有资源。Releases all resources used by the current instance of the HashAlgorithm class.

(Inherited from HashAlgorithm)
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)

释放由 SHA256Managed 对象使用的非托管资源并(可选)释放托管资源。Releases unmanaged resources used by the SHA256Managed object 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()
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)
HashCore(Byte[], Int32, Int32) HashCore(Byte[], Int32, Int32) HashCore(Byte[], Int32, Int32) HashCore(Byte[], Int32, Int32)

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。When overridden in a derived class, routes data written to the object into the SHA256 hash algorithm for computing the hash.

HashCore(ReadOnlySpan<Byte>) HashCore(ReadOnlySpan<Byte>) HashCore(ReadOnlySpan<Byte>) HashCore(ReadOnlySpan<Byte>)
HashFinal() HashFinal() HashFinal() HashFinal()

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。When overridden in a derived class, finalizes the hash computation after the last data is processed by the cryptographic stream object.

Initialize() Initialize() Initialize() Initialize()

初始化 SHA256Managed 的实例。Initializes an instance of SHA256Managed.

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)
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)
TransformBlock(Byte[], Int32, Int32, Byte[], Int32) TransformBlock(Byte[], Int32, Int32, Byte[], Int32) TransformBlock(Byte[], Int32, Int32, Byte[], Int32) TransformBlock(Byte[], Int32, Int32, Byte[], Int32)

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。Computes the hash value for the specified region of the input byte array and copies the specified region of the input byte array to the specified region of the output byte array.

(Inherited from HashAlgorithm)
TransformFinalBlock(Byte[], Int32, Int32) TransformFinalBlock(Byte[], Int32, Int32) TransformFinalBlock(Byte[], Int32, Int32) TransformFinalBlock(Byte[], Int32, Int32)

计算指定字节数组的指定区域的哈希值。Computes the hash value for the specified region of the specified byte array.

(Inherited from HashAlgorithm)
TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32) TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32) TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32) TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32) Inherited from HashAlgorithm
TryHashFinal(Span<Byte>, Int32) TryHashFinal(Span<Byte>, Int32) TryHashFinal(Span<Byte>, Int32) TryHashFinal(Span<Byte>, Int32)

属性

CanReuseTransform CanReuseTransform CanReuseTransform CanReuseTransform

获取一个值,该值指示是否可重复使用当前转换。Gets a value indicating whether the current transform can be reused.

(Inherited from HashAlgorithm)
CanTransformMultipleBlocks CanTransformMultipleBlocks CanTransformMultipleBlocks CanTransformMultipleBlocks

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。When overridden in a derived class, gets a value indicating whether multiple blocks can be transformed.

(Inherited from HashAlgorithm)
Hash Hash Hash Hash

获取计算所得的哈希代码的值。Gets the value of the computed hash code.

(Inherited from HashAlgorithm)
HashSize HashSize HashSize HashSize

获取计算所得的哈希代码的大小(以位为单位)。Gets the size, in bits, of the computed hash code.

(Inherited from HashAlgorithm)
InputBlockSize InputBlockSize InputBlockSize InputBlockSize

当在派生类中重写时,获取输入块的大小。When overridden in a derived class, gets the input block size.

(Inherited from HashAlgorithm)
OutputBlockSize OutputBlockSize OutputBlockSize OutputBlockSize

当在派生类中重写时,获取输出块的大小。When overridden in a derived class, gets the output block size.

(Inherited from HashAlgorithm)

字段

HashSizeValue HashSizeValue HashSizeValue HashSizeValue

表示计算所得的哈希代码的大小(以位为单位)。Represents the size, in bits, of the computed hash code.

(Inherited from HashAlgorithm)
HashValue HashValue HashValue HashValue

表示计算所得的哈希代码的值。Represents the value of the computed hash code.

(Inherited from HashAlgorithm)
State State State State

表示哈希计算的状态。Represents the state of the hash computation.

(Inherited from HashAlgorithm)

显式界面实现

IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose() IDisposable.Dispose()

释放由 HashAlgorithm 占用的非托管资源,还可以另外再释放托管资源。Releases the unmanaged resources used by the HashAlgorithm and optionally releases the managed resources.

(Inherited from HashAlgorithm)

适用于

另请参阅