DES.Create Méthode

Référence

Définition

Espace de noms:: System.Security.Cryptography

Assembly:: System.Security.Cryptography.Algorithms.dll

Assembly:: System.Security.Cryptography.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

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Crée une instance d’un objet de chiffrement pour exécuter l’algorithme Data Encryption Standard (DES).

Surcharges

Create()	Crée une instance d’un objet de chiffrement pour exécuter l’algorithme Data Encryption Standard (DES).
Create(String)	Obsolète. Crée une instance d'un objet de chiffrement pour exécuter l'implémentation spécifiée de l'algorithme Data Encryption Standard (DES).

Create()

Source:: DES.cs

Source:: DES.cs

Source:: DES.cs

Crée une instance d’un objet de chiffrement pour exécuter l’algorithme Data Encryption Standard (DES).

public:
 static System::Security::Cryptography::DES ^ Create();

public static System.Security.Cryptography.DES Create ();

[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public static System.Security.Cryptography.DES Create ();

static member Create : unit -> System.Security.Cryptography.DES

[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
static member Create : unit -> System.Security.Cryptography.DES

Public Shared Function Create () As DES

Retours

DES

Objet de chiffrement.

Attributs: UnsupportedOSPlatformAttribute

Exemples

L’exemple de code suivant montre comment créer et utiliser un DES objet pour chiffrer et déchiffrer des données dans un fichier.

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

void EncryptTextToFile(String^ text, String^ path, array<Byte>^ key, array<Byte>^ iv);
String^ DecryptTextFromFile(String^ path, array<Byte>^ key, array<Byte>^ iv);

int main()
{
    try
    {
        array<Byte>^ key;
        array<Byte>^ iv;

        // Create a new DES object to generate a random key
        // and initialization vector (IV).
        {
            DES^ des;

            try
            {
                des = DES::Create();
                key = des->Key;
                iv = des->IV;
            }
            finally
            {
                delete des;
            }
        }

        // Create a string to encrypt.
        String^ original = "Here is some data to encrypt.";
        // The name/path of the file to write.
        String^ filename = "CText.enc";

        // Encrypt the string to a file.
        EncryptTextToFile(original, filename, key, iv);

        // Decrypt the file back to a string.
        String^ decrypted = DecryptTextFromFile(filename, key, iv);

        // Display the decrypted string to the console.
        Console::WriteLine(decrypted);
    }
    catch (Exception^ e)
    {
        Console::WriteLine(e->Message);
    }
}

void EncryptTextToFile(String^ text, String^ path, array<Byte>^ key, array<Byte>^ iv)
{
    FileStream^ fStream = nullptr;
    DES^ des = nullptr;
    ICryptoTransform^ encryptor = nullptr;
    CryptoStream^ cStream = nullptr;

    try
    {
        // Create or open the specified file.
        fStream = File::Open(path, FileMode::Create);
        // Create a new DES object.
        des = DES::Create();
        // Create a DES encryptor from the key and IV
        encryptor = des->CreateEncryptor(key, iv);
        // Create a CryptoStream using the FileStream and encryptor
        cStream = gcnew CryptoStream(fStream, encryptor, CryptoStreamMode::Write);
        
        // Convert the provided string to a byte array.
        array<Byte>^ toEncrypt = Encoding::UTF8->GetBytes(text);

        // Write the byte array to the crypto stream.
        cStream->Write(toEncrypt, 0, toEncrypt->Length);
    }
    catch (CryptographicException^ e)
    {
        Console::WriteLine("A Cryptographic error occurred: {0}", e->Message);
        throw;
    }
    finally
    {
        if (cStream != nullptr)
            delete cStream;

        if (encryptor != nullptr)
            delete encryptor;

        if (des != nullptr)
            delete des;

        if (fStream != nullptr)
            delete fStream;
    }
}

String^ DecryptTextFromFile(String^ path, array<Byte>^ key, array<Byte>^ iv)
{
    FileStream^ fStream = nullptr;
    DES^ des = nullptr;
    ICryptoTransform^ decryptor = nullptr;
    CryptoStream^ cStream = nullptr;
    StreamReader^ reader = nullptr;

    try
    {
        // Open the specified file
        fStream = File::OpenRead(path);
        // Create a new DES object.
        des = DES::Create();
        // Create a DES decryptor from the key and IV
        decryptor = des->CreateDecryptor(key, iv);
        // Create a CryptoStream using the FileStream and decryptor
        cStream = gcnew CryptoStream(fStream, decryptor, CryptoStreamMode::Read);
        // Create a StreamReader to turn the bytes back into text
        reader = gcnew StreamReader(cStream, Encoding::UTF8);

        // Read back all of the text from the StreamReader, which receives
        // the decrypted bytes from the CryptoStream, which receives the
        // encrypted bytes from the FileStream.
        return reader->ReadToEnd();
    }
    catch (CryptographicException^ e)
    {
        Console::WriteLine("A Cryptographic error occurred: {0}", e->Message);
        throw;
    }
    finally
    {
        if (cStream != nullptr)
            delete cStream;

        if (decryptor != nullptr)
            delete decryptor;

        if (des != nullptr)
            delete des;

        if (fStream != nullptr)
            delete fStream;
    }
}

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

class DESSample
{
    static void Main()
    {
        try
        {
            byte[] key;
            byte[] iv;

            // Create a new DES object to generate a random key
            // and initialization vector (IV).
            using (DES des = DES.Create())
            {
                key = des.Key;
                iv = des.IV;
            }

            // Create a string to encrypt.
            string original = "Here is some data to encrypt.";
            // The name/path of the file to write.
            string filename = "CText.enc";

            // Encrypt the string to a file.
            EncryptTextToFile(original, filename, key, iv);

            // Decrypt the file back to a string.
            string decrypted = DecryptTextFromFile(filename, key, iv);

            // Display the decrypted string to the console.
            Console.WriteLine(decrypted);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static void EncryptTextToFile(string text, string path, byte[] key, byte[] iv)
    {
        try
        {
            // Create or open the specified file.
            using (FileStream fStream = File.Open(path, FileMode.Create))
            // Create a new DES object.
            using (DES des = DES.Create())
            // Create a DES encryptor from the key and IV
            using (ICryptoTransform encryptor = des.CreateEncryptor(key, iv))
            // Create a CryptoStream using the FileStream and encryptor
            using (var cStream = new CryptoStream(fStream, encryptor, CryptoStreamMode.Write))
            {
                // Convert the provided string to a byte array.
                byte[] toEncrypt = Encoding.UTF8.GetBytes(text);

                // Write the byte array to the crypto stream.
                cStream.Write(toEncrypt, 0, toEncrypt.Length);
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }

    public static string DecryptTextFromFile(string path, byte[] key, byte[] iv)
    {
        try
        {
            // Open the specified file
            using (FileStream fStream = File.OpenRead(path))
            // Create a new DES object.
            using (DES des = DES.Create())
            // Create a DES decryptor from the key and IV
            using (ICryptoTransform decryptor = des.CreateDecryptor(key, iv))
            // Create a CryptoStream using the FileStream and decryptor
            using (var cStream = new CryptoStream(fStream, decryptor, CryptoStreamMode.Read)) 
            // Create a StreamReader to turn the bytes back into text
            using (StreamReader reader = new StreamReader(cStream, Encoding.UTF8))
            {
                // Read back all of the text from the StreamReader, which receives
                // the decrypted bytes from the CryptoStream, which receives the
                // encrypted bytes from the FileStream.
                return reader.ReadToEnd();
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }
}

Imports System.IO
Imports System.Security.Cryptography
Imports System.Text

Module DESSample

    Sub Main()
        Try
            Dim key As Byte()
            Dim iv As Byte()

            ' Create a new DES object to generate a key
            ' and initialization vector (IV).
            Using des As DES = DES.Create
                key = des.Key
                iv = des.IV
            End Using

            ' Create a string to encrypt.
            Dim original As String = "Here is some data to encrypt."
            ' The name/path of the file to write.
            Dim filename As String = "CText.enc"

            ' Encrypt the string to a file.
            EncryptTextToFile(original, filename, key, iv)

            ' Decrypt the file back to a string.
            Dim decrypted As String = DecryptTextFromFile(filename, key, iv)

            ' Display the decrypted string to the console.
            Console.WriteLine(decrypted)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub


    Sub EncryptTextToFile(text As String, path As String, key As Byte(), iv As Byte())
        Try
            ' Create or open the specified file.
            ' Create a new DES object,
            ' Create a DES encryptor from the key and IV,
            ' Create a CryptoStream using the MemoryStream And encryptor
            Using fStream As FileStream = File.Open(path, FileMode.Create),
                des As DES = DES.Create,
                encryptor As ICryptoTransform = des.CreateEncryptor(key, iv),
                cStream = New CryptoStream(fStream, encryptor, CryptoStreamMode.Write)

                ' Convert the passed string to a byte array.
                Dim toEncrypt As Byte() = Encoding.UTF8.GetBytes(text)

                ' Write the byte array to the crypto stream.
                cStream.Write(toEncrypt, 0, toEncrypt.Length)
            End Using

        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Throw
        End Try
    End Sub


    Function DecryptTextFromFile(path As String, key As Byte(), iv As Byte()) As String
        Try
            ' Open the specified file
            ' Create a new DES object.
            ' Create a DES decryptor from the key and IV
            ' Create a CryptoStream using the MemoryStream and decryptor
            ' Create a StreamReader to turn the bytes back into text
            Using mStream As FileStream = File.OpenRead(path),
                des As DES = DES.Create,
                decryptor As ICryptoTransform = des.CreateDecryptor(key, iv),
                cStream = New CryptoStream(mStream, decryptor, CryptoStreamMode.Read),
                reader = New StreamReader(cStream, Encoding.UTF8)

                ' Read back all of the text from the StreamReader, which receives
                ' the decrypted bytes from the CryptoStream, which receives the
                ' encrypted bytes from the FileStream.
                Return reader.ReadToEnd()
            End Using
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function
End Module

L’exemple de code suivant montre comment créer et utiliser un DES objet pour chiffrer et déchiffrer des données en mémoire.

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

array<Byte>^ EncryptTextToMemory(String^ text, array<Byte>^ key, array<Byte>^ iv);
String^ DecryptTextFromMemory(array<Byte>^ encrypted, array<Byte>^ key, array<Byte>^ iv);

int main()
{
    try
    {
        array<Byte>^ key;
        array<Byte>^ iv;

        // Create a new DES object to generate a random key
        // and initialization vector (IV).
        {
            DES^ des;

            try
            {
                des = DES::Create();
                key = des->Key;
                iv = des->IV;
            }
            finally
            {
                delete des;
            }
        }

        // Create a string to encrypt.
        String^ original = "Here is some data to encrypt.";

        // Encrypt the string to an in-memory buffer.
        array<Byte>^ encrypted = EncryptTextToMemory(original, key, iv);

        // Decrypt the buffer back to a string.
        String^ decrypted = DecryptTextFromMemory(encrypted, key, iv);

        // Display the decrypted string to the console.
        Console::WriteLine(decrypted);
    }
    catch (Exception^ e)
    {
        Console::WriteLine(e->Message);
    }
}

array<Byte>^ EncryptTextToMemory(String^ text, array<Byte>^ key, array<Byte>^ iv)
{
    MemoryStream^ mStream = nullptr;

    try
    {
        // Create a MemoryStream.
        mStream = gcnew MemoryStream;
        
        DES^ des = nullptr;
        ICryptoTransform^ encryptor = nullptr;
        CryptoStream^ cStream = nullptr;

        try
        {
            // Create a new DES object.
            des = DES::Create();
            // Create a DES encryptor from the key and IV
            encryptor = des->CreateEncryptor(key, iv);
            // Create a CryptoStream using the MemoryStream and encryptor
            cStream = gcnew CryptoStream(mStream, encryptor, CryptoStreamMode::Write);

            // Convert the provided string to a byte array.
            array<Byte>^ toEncrypt = Encoding::UTF8->GetBytes(text);

            // Write the byte array to the crypto stream.
            cStream->Write(toEncrypt, 0, toEncrypt->Length);

            // Disposing the CryptoStream completes the encryption and flushes the stream.
            delete cStream;

            // Get an array of bytes from the MemoryStream that holds the encrypted data.
            array<Byte>^ ret = mStream->ToArray();

            // Return the encrypted buffer.
            return ret;
        }
        finally
        {
            if (cStream != nullptr)
                delete cStream;

            if (encryptor != nullptr)
                delete encryptor;

            if (des != nullptr)
                delete des;
        }
    }
    catch (CryptographicException^ e)
    {
        Console::WriteLine("A Cryptographic error occurred: {0}", e->Message);
        throw;
    }
    finally
    {
        if (mStream != nullptr)
            delete mStream;
    }
}

String^ DecryptTextFromMemory(array<Byte>^ encrypted, array<Byte>^ key, array<Byte>^ iv)
{
    MemoryStream^ mStream = nullptr;
    DES^ des = nullptr;
    ICryptoTransform^ decryptor = nullptr;
    CryptoStream^ cStream = nullptr;

    try
    {
        // Create buffer to hold the decrypted data.
        // DES-encrypted data will always be slightly bigger than the decrypted data.
        array<Byte>^ decrypted = gcnew array<Byte>(encrypted->Length);
        Int32 offset = 0;

        // Create a new MemoryStream using the provided array of encrypted data.
        mStream = gcnew MemoryStream(encrypted);
        // Create a new DES object.
        des = DES::Create();
        // Create a DES decryptor from the key and IV
        decryptor = des->CreateDecryptor(key, iv);
        // Create a CryptoStream using the MemoryStream and decryptor
        cStream = gcnew CryptoStream(mStream, decryptor, CryptoStreamMode::Read);

        // Keep reading from the CryptoStream until it finishes (returns 0).
        Int32 read = 1;

        while (read > 0)
        {
            read = cStream->Read(decrypted, offset, decrypted->Length - offset);
            offset += read;
        }

        // Convert the buffer into a string and return it.
        return Encoding::UTF8->GetString(decrypted, 0, offset);
    }
    catch (CryptographicException^ e)
    {
        Console::WriteLine("A Cryptographic error occurred: {0}", e->Message);
        throw;
    }
    finally
    {
        if (cStream != nullptr)
            delete cStream;

        if (decryptor != nullptr)
            delete decryptor;

        if (des != nullptr)
            delete des;

        if (mStream != nullptr)
            delete mStream;
    }
}

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class DESSample2
{
    static void Main()
    {
        try
        {
            byte[] key;
            byte[] iv;

            // Create a new DES object to generate a random key
            // and initialization vector (IV).
            using (DES des = DES.Create())
            {
                key = des.Key;
                iv = des.IV;
            }

            // Create a string to encrypt.
            string original = "Here is some data to encrypt.";

            // Encrypt the string to an in-memory buffer.
            byte[] encrypted = EncryptTextToMemory(original, key, iv);

            // Decrypt the buffer back to a string.
            string decrypted = DecryptTextFromMemory(encrypted, key, iv);

            // Display the decrypted string to the console.
            Console.WriteLine(decrypted);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    public static byte[] EncryptTextToMemory(string text, byte[] key, byte[] iv)
    {
        try
        {
            // Create a MemoryStream.
            using (MemoryStream mStream = new MemoryStream())
            {
                // Create a new DES object.
                using (DES des = DES.Create())
                // Create a DES encryptor from the key and IV
                using (ICryptoTransform encryptor = des.CreateEncryptor(key, iv))
                // Create a CryptoStream using the MemoryStream and encryptor
                using (var cStream = new CryptoStream(mStream, encryptor, CryptoStreamMode.Write))
                {
                    // Convert the provided string to a byte array.
                    byte[] toEncrypt = Encoding.UTF8.GetBytes(text);

                    // Write the byte array to the crypto stream and flush it.
                    cStream.Write(toEncrypt, 0, toEncrypt.Length);

                    // Ending the using statement for the CryptoStream completes the encryption.
                }

                // Get an array of bytes from the MemoryStream that holds the encrypted data.
                byte[] ret = mStream.ToArray();

                // Return the encrypted buffer.
                return ret;
            }
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }

    public static string DecryptTextFromMemory(byte[] encrypted, byte[] key, byte[] iv)
    {
        try
        {
            // Create a buffer to hold the decrypted data.
            // DES-encrypted data will always be slightly bigger than the decrypted data.
            byte[] decrypted = new byte[encrypted.Length];
            int offset = 0;

            // Create a new MemoryStream using the provided array of encrypted data.
            using (MemoryStream mStream = new MemoryStream(encrypted))
            {
                // Create a new DES object.
                using (DES des = DES.Create())
                // Create a DES decryptor from the key and IV
                using (ICryptoTransform decryptor = des.CreateDecryptor(key, iv))
                // Create a CryptoStream using the MemoryStream and decryptor
                using (var cStream = new CryptoStream(mStream, decryptor, CryptoStreamMode.Read))
                {
                    // Keep reading from the CryptoStream until it finishes (returns 0).
                    int read = 1;

                    while (read > 0)
                    {
                        read = cStream.Read(decrypted, offset, decrypted.Length - offset);
                        offset += read;
                    }
                }
            }

            // Convert the buffer into a string and return it.
            return Encoding.UTF8.GetString(decrypted, 0, offset);
        }
        catch (CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            throw;
        }
    }
}

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Module DESSample

    Sub Main()
        Try
            Dim key As Byte()
            Dim iv As Byte()

            ' Create a new DES object to generate a key
            ' and initialization vector (IV).
            Using des As DES = DES.Create
                key = des.Key
                iv = des.IV
            End Using

            ' Create a string to encrypt.
            Dim original As String = "Here is some data to encrypt."

            ' Encrypt the string to an in-memory buffer.
            Dim encrypted As Byte() = EncryptTextToMemory(original, key, iv)

            ' Decrypt the buffer back to a string.
            Dim decrypted As String = DecryptTextFromMemory(encrypted, key, iv)

            ' Display the decrypted string to the console.
            Console.WriteLine(decrypted)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub


    Function EncryptTextToMemory(text As String, key As Byte(), iv As Byte()) As Byte()
        Try
            ' Create a MemoryStream.
            Using mStream As New MemoryStream
                ' Create a new DES object,
                ' Create a DES encryptor from the key and IV,
                ' Create a CryptoStream using the MemoryStream And encryptor
                Using des As DES = DES.Create,
                    encryptor As ICryptoTransform = des.CreateEncryptor(key, iv),
                    cStream = New CryptoStream(mStream, encryptor, CryptoStreamMode.Write)

                    ' Convert the passed string to a byte array.
                    Dim toEncrypt As Byte() = Encoding.UTF8.GetBytes(text)

                    ' Write the byte array to the crypto stream and flush it.
                    cStream.Write(toEncrypt, 0, toEncrypt.Length)

                    ' Ending the using block for the CryptoStream completes the encryption.
                End Using

                ' Get an array of bytes from the MemoryStream that holds the encrypted data.
                Dim ret As Byte() = mStream.ToArray()

                ' Return the encrypted buffer.
                Return ret
            End Using
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Throw
        End Try
    End Function


    Function DecryptTextFromMemory(encrypted As Byte(), key As Byte(), iv As Byte()) As String
        Try
            ' Create a buffer to hold the decrypted data.
            ' DES-encrypted data will always be slightly bigger than the decrypted data.
            Dim decrypted(encrypted.Length - 1) As Byte
            Dim offset As Integer = 0

            ' Create a new MemoryStream using the provided array of encrypted data.
            ' Create a new DES object.
            ' Create a DES decryptor from the key and IV
            ' Create a CryptoStream using the MemoryStream and decryptor
            Using mStream As New MemoryStream(encrypted),
                des As DES = DES.Create,
                decryptor As ICryptoTransform = des.CreateDecryptor(key, iv),
                cStream = New CryptoStream(mStream, decryptor, CryptoStreamMode.Read)

                ' Keep reading from the CryptoStream until it finishes (returns 0).
                Dim read As Integer = 1

                While (read > 0)
                    read = cStream.Read(decrypted, offset, decrypted.Length - offset)
                    offset += read
                End While
            End Using

            ' Convert the buffer into a string and return it.
            Return New ASCIIEncoding().GetString(decrypted, 0, offset)
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function
End Module

Remarques

Crée une instance de l’objet DES qui peut être utilisée pour le chiffrement et le déchiffrement des données.

Voir aussi

services de chiffrement

S’applique à

Create(String)

Source:: DES.cs

Source:: DES.cs

Source:: DES.cs

Attention

Cryptographic factory methods accepting an algorithm name are obsolete. Use the parameterless Create factory method on the algorithm type instead.

Crée une instance d'un objet de chiffrement pour exécuter l'implémentation spécifiée de l'algorithme Data Encryption Standard (DES).

public:
 static System::Security::Cryptography::DES ^ Create(System::String ^ algName);

public static System.Security.Cryptography.DES? Create (string algName);

[System.Obsolete("Cryptographic factory methods accepting an algorithm name are obsolete. Use the parameterless Create factory method on the algorithm type instead.", DiagnosticId="SYSLIB0045", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public static System.Security.Cryptography.DES? Create (string algName);

public static System.Security.Cryptography.DES Create (string algName);

static member Create : string -> System.Security.Cryptography.DES

[<System.Obsolete("Cryptographic factory methods accepting an algorithm name are obsolete. Use the parameterless Create factory method on the algorithm type instead.", DiagnosticId="SYSLIB0045", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
static member Create : string -> System.Security.Cryptography.DES

Public Shared Function Create (algName As String) As DES

Paramètres

algName: String

Nom de l'implémentation spécifique de DES à utiliser.

Retours

DES

Objet de chiffrement.

Attributs: ObsoleteAttribute

Voir aussi

services de chiffrement

S’applique à

Partager via

DES.Create Méthode

Définition

Surcharges

Create()

Retours

Exemples

Remarques

Voir aussi

S’applique à

Create(String)

Paramètres

Retours

Voir aussi

S’applique à

Ressources supplémentaires