Codice sorgente di Alice.cs (esempio CNG)

Aggiornamento: Luglio 2008

L'esempio di comunicazione protetta tramite Cryptography Next Generation (CNG) è costituito da tre applicazioni console: Alice, Bob e Mallory. L'applicazione Alice (file Alice.cs) contiene il codice seguente.

using System;                           // Required for the IDisposable interface
using System.Text;                      // Required for the Encoding class
using System.Security.Cryptography;     // Required for the CNG APIs


public partial class CNG_SecureCommunicationExample
{
                                        // Global variables
static int  MyColor    = 4;             // Alice Green displays green text
static int  OtherColor = 2;             // Bob White displays white text

static void Main()
    {
    if (!Autoloader())                  // Load Bob and Mallory
        return;                         // An error was encountered during load.

    string s = "";
    InitConsole("Alice Green", 5, 5);
    while (true)
        {
        SplashScreen();                 // Set and display titles
        s = InitializeOptions();        // Get session options
        AppControl("send", s);          // Synchronize Bob and Mallory
        if ("exit" == s)                // Quit if user entered "x"
            break; 
        Run();                          // Run the desired session
        }
    }                                   // End Main


//---------------------------------------------------------------------------------------

static void Run()
    {
    string NewChannelName = "AliceAndBobChannel";   
    SendChannelName(NewChannelName);    // Bad corporate security policy 

    Display("Hi, I'm Alice Green. My sales associate is Bob White.\n" +
            "I need to send him a customer order right now!\n\n");

    using (Communicator Alice = new Communicator("server", NewChannelName))
        {
        string s;

        CngKeyCreationParameters keyCreateParms = new CngKeyCreationParameters();
        keyCreateParms.ExportPolicy = CngExportPolicies.AllowPlaintextExport;

        if (3 <= Version)              // Send public digital signature key
            {
            using (CngKey DSKey = CngKey.Create(CngAlgorithm.ECDsaP521, null, keyCreateParms))
                {
                byte[] dsKeyBlob = DSKey.Export(CngKeyBlobFormat.Pkcs8PrivateBlob);
                Alice.StoreDSKey(dsKeyBlob);
                s = Encoding.ASCII.GetString(dsKeyBlob);
                Display("\nFirst, I will send Bob a digital signature key "
                        +"over a public channel.\n" +
                        (fVerbose ? "Here it is:\n\n" + s + "\n\n" : ""));
                Alice.ChMgr.SendMessage(dsKeyBlob);
                }
            }

        if (4 <= Version)              // Send private digital signature key
            {
            using (CngKey DSKey = CngKey.Create(CngAlgorithm.ECDsaP521, null, keyCreateParms))
            using(ChannelManager ChMgr2 = new ChannelManager("server", "PrivateChannel"))
                {
                byte[] dsKeyBlob = DSKey.Export(CngKeyBlobFormat.Pkcs8PrivateBlob);
                Alice.StoreDSKey(dsKeyBlob);
                s = Encoding.ASCII.GetString(dsKeyBlob);
                Display("\nNow I will send Bob a secret digital signature key " +
                        "over a private channel.\n" + 
                        (fVerbose ? "Here it is:\n\n" + s + "\n\n" : ""));
                ChMgr2.SendMessage(dsKeyBlob);
                }
            }

        if (2 <= Version)              // Send and receive public cryptographic keys
            {
            Display(sep2, 1);
            Display("Now we will exchange our public cryptographic\n" +
                    "keys through a public channel\n" +
                    "First, I'll send Bob my key.\n\nSending...\n");
            Alice.Send_or_Receive_PublicCryptoKey("send", MyColor);


            Display(sep2, 1);
            Display("Now Bob will publically send me his "  +
                    "public crypto key:\n\nListening...\n");
            if (!Alice.Send_or_Receive_PublicCryptoKey("receive", OtherColor))
                {
                Display("", 6);
                return;
                }
            }

    //-----------------------------------------------------------------------------------
    // Now that all the keys have been transmitted, have a conversation.

        if (1 < Version)
            {
            Display(sep2, 1);
            Display("Now that our keys have been exchanged,\n" +
                   "we can have an encrypted conversation:\n\n", 4);
            Display(sep1, 1);
            }

        Alice.SendMessage("Hi Bob. I have a new customer contact.",true);
        Alice.ReceiveMessage();
        Alice.SendMessage("Coho Winery, 111 AnyStreet, Chicago",true);
        Alice.ReceiveMessage();

        if (Version <= 2)
            Display(sep1, 1);

        if (!fVerbose && Version >= 3)
            Display(sep1, 1);

    //-----------------------------------------------------------------------------------
        Display("Would you like to talk to Bob?\n" +
                "If so, type a message, and press Enter.\n" +
               "Otherwise, just press Enter.\n\n", 1);
        Display(sep + sep1,1);
        s = " ";


        while (true)
            {
            s = ReadALine(true); 
            if (!Alice.SendMessage(s,false))    // If Bob entered CTRL-C, or SYS_CLOSE
                break;
            if ("" == s)                        // If user entered ""
                break;
            s = Alice.ReceiveMessage();         // Read a message
            if ("" == s)
                break;
            }

    //-----------------------------------------------------------------------------------
        }   // End using ChannelManager, End using Communicator
    }       // End Run

}       // End Alice.cs: public partial class CNG_SecureCommunicationExample

Vedere anche

Attività

Procedura: compilare ed eseguire l'esempio CNG

Concetti

Cenni preliminari sul codice sorgente (esempio CNG)

Esempio di comunicazione protetta tramite Cryptography Next Generation (CNG)

Altre risorse

Servizi di crittografia

Cronologia delle modifiche

Data	Cronologia	Motivo
Luglio 2008	Argomento aggiunto.	Miglioramento delle informazioni.