SHA256Managed SHA256Managed SHA256Managed SHA256Managed Class

Définition

Calcule le SHA256 hachage pour les données d’entrée à l’aide de la bibliothèque managée.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
Héritage
Attributs

Exemples

L’exemple suivant calcule le hachage SHA-256 pour tous les fichiers dans un répertoire.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
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

Remarques

Le hachage est utilisé en tant que valeur unique de taille fixe représentant une grande quantité de données.The hash is used as a unique value of fixed size representing a large amount of data. Hachages de deux jeux de données doivent correspondre si et seulement si les données correspondantes correspond également à.Hashes of two sets of data should match if and only if the corresponding data also matches. Petites modifications aux données entraîne des modifications importantes et imprévisibles dans le hachage.Small changes to the data result in large unpredictable changes in the hash.

La taille de hachage pour le SHA256Managed algorithme est de 256 bits.The hash size for the SHA256Managed algorithm is 256 bits.

Constructeurs

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

Initialise une nouvelle instance de la SHA256Managed classe à l’aide de la bibliothèque managée.Initializes a new instance of the SHA256Managed class using the managed library.

Méthodes

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

Libère toutes les ressources utilisées par la classe HashAlgorithm.Releases all resources used by the HashAlgorithm class.

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

Calcule la valeur de hachage pour le tableau d'octets spécifié.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)

Calcule la valeur de hachage pour la région spécifiée du tableau d'octets spécifié.Computes the hash value for the specified region of the specified byte array.

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

Calcule la valeur de hachage pour l'objet Stream spécifié.Computes the hash value for the specified Stream object.

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

Libère toutes les ressources utilisées par l'instance actuelle de la classe HashAlgorithm.Releases all resources used by the current instance of the HashAlgorithm class.

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

Libère les ressources non managées utilisées par l’objet SHA256Managed et libère éventuellement les ressources managées.Releases unmanaged resources used by the SHA256Managed object and optionally releases the managed resources.

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

Détermine si l'objet spécifié est identique à l'objet actuel.Determines whether the specified object is equal to the current object.

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

Fait office de fonction de hachage par défaut.Serves as the default hash function.

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

Obtient le Type de l'instance actuelle.Gets 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)

En cas de substitution dans une classe dérivée, achemine les données écrites dans l’objet vers le SHA256 algorithme de hachage pour calculer le hachage.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()

En cas de substitution dans une classe dérivée, finalise le calcul de hachage une fois les dernières données traitées par l'objet de flux de chiffrement.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()

Initialise une instance de SHA256Managed.Initializes an instance of SHA256Managed.

MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crée une copie superficielle du Object actuel.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Retourne une chaîne qui représente l'objet actuel.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)

Calcule la valeur de hachage pour la région spécifiée du tableau d'octets d'entrée et copie la région spécifiée du tableau d'octets d'entrée dans la région spécifiée du tableau d'octets de sortie.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)

Calcule la valeur de hachage pour la région spécifiée du tableau d'octets spécifié.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)

Propriétés

CanReuseTransform CanReuseTransform CanReuseTransform CanReuseTransform

Obtient une valeur indiquant si la transformation actuelle peut être réutilisée.Gets a value indicating whether the current transform can be reused.

(Inherited from HashAlgorithm)
CanTransformMultipleBlocks CanTransformMultipleBlocks CanTransformMultipleBlocks CanTransformMultipleBlocks

En cas de substitution dans une classe dérivée, obtient une valeur indiquant si plusieurs blocs peuvent être transformés.When overridden in a derived class, gets a value indicating whether multiple blocks can be transformed.

(Inherited from HashAlgorithm)
Hash Hash Hash Hash

Obtient la valeur du code de hachage calculé.Gets the value of the computed hash code.

(Inherited from HashAlgorithm)
HashSize HashSize HashSize HashSize

Obtient la taille, en bits, du code de hachage calculé.Gets the size, in bits, of the computed hash code.

(Inherited from HashAlgorithm)
InputBlockSize InputBlockSize InputBlockSize InputBlockSize

En cas de substitution dans une classe dérivée, obtient la taille du bloc d'entrée.When overridden in a derived class, gets the input block size.

(Inherited from HashAlgorithm)
OutputBlockSize OutputBlockSize OutputBlockSize OutputBlockSize

En cas de substitution dans une classe dérivée, obtient la taille du bloc de sortie.When overridden in a derived class, gets the output block size.

(Inherited from HashAlgorithm)

Champs

HashSizeValue HashSizeValue HashSizeValue HashSizeValue

Représente la taille, en bits, du code de hachage calculé.Represents the size, in bits, of the computed hash code.

(Inherited from HashAlgorithm)
HashValue HashValue HashValue HashValue

Représente la valeur du code de hachage calculé.Represents the value of the computed hash code.

(Inherited from HashAlgorithm)
State State State State

Représente l'état du calcul du hachage.Represents the state of the hash computation.

(Inherited from HashAlgorithm)

Implémentations d’interfaces explicites

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

Libère les ressources non managées utilisées par HashAlgorithm et libère éventuellement les ressources managées.Releases the unmanaged resources used by the HashAlgorithm and optionally releases the managed resources.

(Inherited from HashAlgorithm)

S’applique à

Voir aussi