SHA256Managed Clase

Definición

Calcula el valor hash de SHA256 de los datos de entrada utilizando la biblioteca administrada.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
Herencia
SHA256Managed
Atributos

Ejemplos

En el ejemplo siguiente se calcula el hash SHA-256 para todos los archivos de un directorio.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

Comentarios

El hash se usa como un valor único de tamaño fijo que representa una gran cantidad de datos.The hash is used as a unique value of fixed size representing a large amount of data. Los valores hash de dos conjuntos de datos deben coincidir si y solo si los datos correspondientes también coinciden.Hashes of two sets of data should match if and only if the corresponding data also matches. Los pequeños cambios en los datos producen cambios imprevisibles grandes en el hash.Small changes to the data result in large unpredictable changes in the hash.

El tamaño de hash para SHA256Managed el algoritmo es 256 bits.The hash size for the SHA256Managed algorithm is 256 bits.

Constructores

SHA256Managed()

Inicializa una nueva instancia de la clase SHA256Managed utilizando la biblioteca administrada.Initializes a new instance of the SHA256Managed class using the managed library.

Campos

HashSizeValue

Representa el tamaño en bits del código hash calculado.Represents the size, in bits, of the computed hash code.

(Heredado de HashAlgorithm)
HashValue

Representa el valor del código hash calculado.Represents the value of the computed hash code.

(Heredado de HashAlgorithm)
State

Representa el estado del cálculo del valor hash.Represents the state of the hash computation.

(Heredado de HashAlgorithm)

Propiedades

CanReuseTransform

Obtiene un valor que indica si la transformación actual puede volver a usarse.Gets a value indicating whether the current transform can be reused.

(Heredado de HashAlgorithm)
CanTransformMultipleBlocks

Cuando se invalida en una clase derivada, obtiene un valor que indica si se pueden transformar varios bloques.When overridden in a derived class, gets a value indicating whether multiple blocks can be transformed.

(Heredado de HashAlgorithm)
Hash

Obtiene el valor del código hash calculado.Gets the value of the computed hash code.

(Heredado de HashAlgorithm)
HashSize

Obtiene el tamaño en bits del código hash calculado.Gets the size, in bits, of the computed hash code.

(Heredado de HashAlgorithm)
InputBlockSize

Cuando se invalida en una clase derivada, obtiene el tamaño del bloque de entrada.When overridden in a derived class, gets the input block size.

(Heredado de HashAlgorithm)
OutputBlockSize

Cuando se invalida en una clase derivada, obtiene el tamaño del bloque de salida.When overridden in a derived class, gets the output block size.

(Heredado de HashAlgorithm)

Métodos

Clear()

Libera todos los recursos que utiliza la clase HashAlgorithm.Releases all resources used by the HashAlgorithm class.

(Heredado de HashAlgorithm)
ComputeHash(Byte[])

Calcula el valor hash para la matriz de bytes especificada.Computes the hash value for the specified byte array.

(Heredado de HashAlgorithm)
ComputeHash(Byte[], Int32, Int32)

Calcula el valor hash para la región especificada de la matriz de bytes indicada.Computes the hash value for the specified region of the specified byte array.

(Heredado de HashAlgorithm)
ComputeHash(Stream)

Calcula el valor hash del objeto Stream especificado.Computes the hash value for the specified Stream object.

(Heredado de HashAlgorithm)
Dispose()

Libera todos los recursos usados por la instancia actual de la clase HashAlgorithm.Releases all resources used by the current instance of the HashAlgorithm class.

(Heredado de HashAlgorithm)
Dispose(Boolean)

Libera los recursos no administrados que usa el objeto SHA256Managed y, opcionalmente, los recursos administrados.Releases unmanaged resources used by the SHA256Managed object and optionally releases the managed resources.

Equals(Object)

Determina si el objeto especificado es igual al objeto actual.Determines whether the specified object is equal to the current object.

(Heredado de Object)
Finalize()
GetHashCode()

Sirve como función hash predeterminada.Serves as the default hash function.

(Heredado de Object)
GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Heredado de Object)
HashCore(Byte[], Int32, Int32)

Cuando se invalida en una clase derivada, enruta los datos escritos en el objeto al algoritmo hash SHA256 para el cálculo del valor hash.When overridden in a derived class, routes data written to the object into the SHA256 hash algorithm for computing the hash.

HashCore(ReadOnlySpan<Byte>)
HashFinal()

Cuando se invalida en una clase derivada, finaliza el cálculo hash una vez que el objeto de secuencia criptográfico termina de procesar los últimos datos.When overridden in a derived class, finalizes the hash computation after the last data is processed by the cryptographic stream object.

Initialize()

Inicializa una instancia de SHA256Managed.Initializes an instance of SHA256Managed.

MemberwiseClone()

Crea una copia superficial del Object actual.Creates a shallow copy of the current Object.

(Heredado de Object)
ToString()

Devuelve un valor de tipo string que representa el objeto actual.Returns a string that represents the current object.

(Heredado de Object)
TransformBlock(Byte[], Int32, Int32, Byte[], Int32)

Calcula el valor hash para la región especificada de la matriz de bytes de entrada y copia la región especificada de la matriz de bytes de entrada resultante en la región indicada de la matriz de bytes de salida.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.

(Heredado de HashAlgorithm)
TransformFinalBlock(Byte[], Int32, Int32)

Calcula el valor hash para la región especificada de la matriz de bytes indicada.Computes the hash value for the specified region of the specified byte array.

(Heredado de HashAlgorithm)
TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32) (Heredado de HashAlgorithm)
TryHashFinal(Span<Byte>, Int32)

Implementaciones de interfaz explícitas

IDisposable.Dispose()

Libera los recursos no administrados que usa HashAlgorithm y, de forma opcional, libera los recursos administrados.Releases the unmanaged resources used by the HashAlgorithm and optionally releases the managed resources.

(Heredado de HashAlgorithm)

Se aplica a

Consulte también: