67 lines
2.1 KiB
C#
67 lines
2.1 KiB
C#
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using System.Net;
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using System.Net.Sockets;
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using System.Security.Cryptography;
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using System.Text;
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new Thread(ServerWorker).Start();
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new Thread(ClientWorker).Start();
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return;
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static void ClientWorker()
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{
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using var socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
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socket.Connect(new IPEndPoint(IPAddress.Loopback, 1234));
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using var stream = new NetworkStream(socket);
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// read public key from server
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using var reader = new BinaryReader(stream);
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using var writer = new BinaryWriter(stream);
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using var rsa = new RSACryptoServiceProvider(2048);
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rsa.ImportParameters(new RSAParameters
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{
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Modulus = reader.ReadBytes(reader.ReadInt32()),
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Exponent = reader.ReadBytes(reader.ReadInt32())
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});
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while (Console.ReadLine() is { } line)
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{
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// encrypt line and send to server
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byte[] encrypted = rsa.Encrypt(Encoding.UTF8.GetBytes(line), RSAEncryptionPadding.OaepSHA1);
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writer.Write(encrypted.Length);
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writer.Write(encrypted);
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}
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}
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static void ServerWorker()
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{
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using var socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
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socket.Bind(new IPEndPoint(IPAddress.Any, 1234));
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socket.Listen(1);
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// generate RSA key pair
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using var rsa = new RSACryptoServiceProvider(2048);
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RSAParameters publicKey = rsa.ExportParameters(false);
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// accept client socket
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using Socket client = socket.Accept();
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using var stream = new NetworkStream(client);
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// write public key
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using var writer = new BinaryWriter(stream);
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writer.Write(publicKey.Modulus!.Length);
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writer.Write(publicKey.Modulus);
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writer.Write(publicKey.Exponent!.Length);
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writer.Write(publicKey.Exponent);
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while (true)
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{
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// read encrypted line from client
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using var reader = new BinaryReader(new NetworkStream(client));
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int length = reader.ReadInt32();
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byte[] encrypted = reader.ReadBytes(length);
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byte[] decrypted = rsa.Decrypt(encrypted, RSAEncryptionPadding.OaepSHA1);
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Console.WriteLine($"Client sent: {Encoding.UTF8.GetString(decrypted)}");
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}
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}
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