Пример #1
0
    public static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;
        Socket fd;

        wolfssl.psk_delegate psk_cb = new wolfssl.psk_delegate(my_psk_server_cb);

        /* These paths should be changed according to use */
        string        fileCert = @"server-cert.pem";
        string        fileKey  = @"server-key.pem";
        StringBuilder dhparam  = new StringBuilder("dh2048.pem");

        StringBuilder buff  = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_new(wolfssl.useTLSv1_2_server());
        if (ctx == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ctx structure");
            return;
        }
        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting cert file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting key file");
            wolfssl.CTX_free(ctx);
            return;
        }


        StringBuilder ciphers = new StringBuilder(new String(' ', 4096));

        wolfssl.get_ciphers(ciphers, 4096);
        Console.WriteLine("Ciphers : " + ciphers.ToString());

        short minDhKey = 128;

        wolfssl.CTX_SetMinDhKey_Sz(ctx, minDhKey);
        Console.Write("Setting cipher suite to ");

        /* In order to use static PSK build wolfSSL with the preprocessor flag WOLFSSL_STATIC_PSK */
        StringBuilder set_cipher = new StringBuilder("DHE-PSK-AES128-CBC-SHA256");

        Console.WriteLine(set_cipher);
        if (wolfssl.CTX_set_cipher_list(ctx, set_cipher) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Failed to set cipher suite");
            return;
        }

        /* Test psk use with DHE */
        StringBuilder hint = new StringBuilder("cyassl server");

        if (wolfssl.CTX_use_psk_identity_hint(ctx, hint) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting hint");
            wolfssl.CTX_free(ctx);
            return;
        }
        wolfssl.CTX_set_psk_server_callback(ctx, psk_cb);

        /* set up TCP socket */
        IPAddress   ip  = IPAddress.Parse("0.0.0.0"); //bind to any
        TcpListener tcp = new TcpListener(ip, 11111);

        tcp.Start();

        Console.WriteLine("Started TCP and waiting for a connection");
        fd  = tcp.AcceptSocket();
        ssl = wolfssl.new_ssl(ctx);
        if (ssl == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ssl object");
            tcp.Stop();
            wolfssl.CTX_free(ctx);
            return;
        }

        Console.WriteLine("Connection made wolfSSL_accept ");
        if (wolfssl.set_fd(ssl, fd) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        wolfssl.SetTmpDH_file(ssl, dhparam, wolfssl.SSL_FILETYPE_PEM);

        if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* read and print out the message then reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error in read");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error in write");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        wolfssl.shutdown(ssl);
        fd.Close();
        tcp.Stop();
        clean(ssl, ctx);
    }
Пример #2
0
        public static void Main(string[] args)
        {
            IntPtr ctx;
            IntPtr ssl;

            wolfssl.loggingCb loggingCb = Log;
            wolfssl.SetLogging(loggingCb);

            wolfssl.psk_delegate psk_cb = new wolfssl.psk_delegate(my_psk_server_cb);

            byte[] buff      = new byte[1024];
            byte[] stubReply = new byte[] { 0xe1, 0x6f, 0x80, 0xff, 0xbe, 0xdc, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02 };

            wolfssl.Init();

            Console.WriteLine("Calling ctx Init from wolfSSL");
            ctx = wolfssl.CTX_dtls_new(wolfssl.useDTLSv1_2_server());
            if (ctx == IntPtr.Zero)
            {
                Console.WriteLine("Error creating ctx structure");
                return;
            }

            Console.WriteLine("Finished init of ctx .... now load in cert and key");


            /* Test psk use with DHE */
            StringBuilder hint = new StringBuilder("PROJECT_76"); //Hardcoded hint in Fo76

            if (wolfssl.CTX_use_psk_identity_hint(ctx, hint) != wolfssl.SUCCESS)
            {
                Console.WriteLine("Error setting hint");
                wolfssl.CTX_free(ctx);
                return;
            }
            wolfssl.CTX_set_psk_server_callback(ctx, psk_cb);

            Console.Write("Setting cipher suite to ");
            StringBuilder set_cipher = new StringBuilder("TLS_PSK_WITH_AES_128_GCM_SHA256");

            Console.WriteLine(set_cipher);
            if (wolfssl.CTX_set_cipher_list(ctx, set_cipher) != wolfssl.SUCCESS)
            {
                Console.WriteLine("Failed to set cipher suite");
                wolfssl.CTX_free(ctx);
                return;
            }

            IPAddress  ip  = IPAddress.Parse("127.0.0.1");
            UdpClient  udp = new UdpClient(3001);
            IPEndPoint ep  = new IPEndPoint(ip, 3001);

            Console.WriteLine("Started UDP and waiting for a connection");

            ssl = wolfssl.new_ssl(ctx);
            if (ssl == IntPtr.Zero)
            {
                Console.WriteLine("Error creating ssl object");
                udp.Close();
                wolfssl.CTX_free(ctx);
                return;
            }

            if (wolfssl.set_dtls_fd(ssl, udp, ep) != wolfssl.SUCCESS)
            {
                Console.WriteLine(wolfssl.get_error(ssl));
                udp.Close();
                clean(ssl, ctx);
                return;
            }

            if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
            {
                Console.WriteLine(wolfssl.get_error(ssl));
                udp.Close();
                clean(ssl, ctx);
                return;
            }

            /* print out results of TLS/SSL accept */
            Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
            Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

            /* get connection information and print ip - port */
            wolfssl.DTLS_con con = wolfssl.get_dtls_fd(ssl);
            Console.Write("Connected to ip ");
            Console.Write(con.ep.Address.ToString());
            Console.Write(" on port ");
            Console.WriteLine(con.ep.Port.ToString());

            /* read information sent and send a reply */
            if (wolfssl.read(ssl, buff, 1023) < 0)
            {
                Console.WriteLine("Error reading message");
                Console.WriteLine(wolfssl.get_error(ssl));
                udp.Close();
                clean(ssl, ctx);
                return;
            }
            Console.WriteLine(ByteArrayToString(buff));

            if (wolfssl.write(ssl, stubReply, stubReply.Length) != stubReply.Length)
            {
                Console.WriteLine("Error writing message");
                Console.WriteLine(wolfssl.get_error(ssl));
                udp.Close();
                clean(ssl, ctx);
                return;
            }

            Console.WriteLine("At the end freeing stuff");
            wolfssl.shutdown(ssl);
            udp.Close();
            clean(ssl, ctx);
        }
    static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;
        Socket fd;

        wolfssl.psk_delegate psk_cb = new wolfssl.psk_delegate(my_psk_server_cb);

        /* These paths should be changed according to use */
        string fileCert = @"server-cert.pem";
        string fileKey = @"server-key.pem";

        StringBuilder buff = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_new(wolfssl.useTLSv1_2_server());
        if (ctx == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ctx structure");
            return;
        }
        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting cert file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        StringBuilder ciphers = new StringBuilder(new String(' ', 4096));
        wolfssl.get_ciphers(ciphers, 4096);
        Console.WriteLine("Ciphers : " + ciphers.ToString());

        Console.Write("Setting cipher suite to ");
        /* To use static PSK build wolfSSL with WOLFSSL_STATIC_PSK preprocessor flag */
        StringBuilder set_cipher = new StringBuilder("PSK-AES128-CBC-SHA256");
        Console.WriteLine(set_cipher);
        if (wolfssl.CTX_set_cipher_list(ctx, set_cipher) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Failed to set cipher suite");
            Console.WriteLine("If using static PSK make sure wolfSSL was built with preprocessor flag WOLFSSL_STATIC_PSK");
            wolfssl.CTX_free(ctx);
            return;
        }

        /* Test psk use */
        StringBuilder hint = new StringBuilder("cyassl server");
        if (wolfssl.CTX_use_psk_identity_hint(ctx, hint) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting hint");
            return;
        }
        wolfssl.CTX_set_psk_server_callback(ctx, psk_cb);

        /* Set using custom IO callbacks
           delegate memory is allocated when calling SetIO**** function and freed with ctx free
         */
        wolfssl.SetIORecv(ctx, new wolfssl.CallbackIORecv_delegate(wolfSSLCbIORecv));
        wolfssl.SetIOSend(ctx, new wolfssl.CallbackIOSend_delegate(wolfSSLCbIOSend));

        /* set up TCP socket */
        IPAddress ip = IPAddress.Parse("0.0.0.0"); //bind to any
        TcpListener tcp = new TcpListener(ip, 11111);
        tcp.Start();

        Console.WriteLine("Started TCP and waiting for a connection");
        fd = tcp.AcceptSocket();
        ssl = wolfssl.new_ssl(ctx);

        Console.WriteLine("Connection made wolfSSL_accept ");
        if (wolfssl.set_fd(ssl, fd) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.Write(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* read and print out the message then reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error in read");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error in write");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        wolfssl.shutdown(ssl);
        fd.Close();
        tcp.Stop();
        clean(ssl, ctx);
    }
    static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;
        Socket fd;

        wolfssl.psk_delegate            psk_cb    = new wolfssl.psk_delegate(my_psk_server_cb);
        wolfssl.CallbackVerify_delegate verify_cb = new wolfssl.CallbackVerify_delegate(my_verify_cb);

        /* These paths should be changed according to use */
        string fileCert = @"server-cert.pem";
        string fileKey  = @"server-key.pem";

        StringBuilder buff  = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_new(wolfssl.useTLSv1_2_server());
        if (ctx == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ctx structure");
            return;
        }
        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting cert file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        wolfssl.CTX_set_verify(ctx, wolfssl.SSL_VERIFY_PEER, verify_cb);

        /* Set using custom IO callbacks
         * delegate memory is allocated when calling SetIO**** function and freed with ctx free
         */
        wolfssl.SetIORecv(ctx, new wolfssl.CallbackIORecv_delegate(wolfSSLCbIORecv));
        wolfssl.SetIOSend(ctx, new wolfssl.CallbackIOSend_delegate(wolfSSLCbIOSend));

        /* set up TCP socket */
        IPAddress   ip  = IPAddress.Parse("0.0.0.0"); //bind to any
        TcpListener tcp = new TcpListener(ip, 11111);

        tcp.Start();

        Console.WriteLine("Started TCP and waiting for a connection");
        fd  = tcp.AcceptSocket();
        ssl = wolfssl.new_ssl(ctx);

        Console.WriteLine("Connection made wolfSSL_accept ");
        if (wolfssl.set_fd(ssl, fd) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.WriteLine(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
        {
            /* get and print out the error */
            Console.WriteLine(wolfssl.get_error(ssl));
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* read and print out the message then reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error in read");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error in write");
            tcp.Stop();
            clean(ssl, ctx);
            return;
        }

        wolfssl.shutdown(ssl);
        fd.Close();
        tcp.Stop();
        clean(ssl, ctx);
    }
Пример #5
0
    public static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;

        /* These paths should be changed according to use */
        string        fileCert = @"server-cert.pem";
        string        fileKey  = @"server-key.pem";
        StringBuilder dhparam  = new StringBuilder("dh2048.pem");

        wolfssl.psk_delegate psk_cb = new wolfssl.psk_delegate(my_psk_server_cb);

        StringBuilder buff  = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_dtls_new(wolfssl.useDTLSv1_2_server());
        if (ctx == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ctx structure");
            return;
        }

        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            wolfssl.CTX_free(ctx);
            return;
        }


        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting cert file");
            wolfssl.CTX_free(ctx);
            return;
        }


        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting key file");
            wolfssl.CTX_free(ctx);
            return;
        }


        /* Test psk use with DHE */
        StringBuilder hint = new StringBuilder("cyassl server");

        if (wolfssl.CTX_use_psk_identity_hint(ctx, hint) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting hint");
            wolfssl.CTX_free(ctx);
            return;
        }
        wolfssl.CTX_set_psk_server_callback(ctx, psk_cb);

        short minDhKey = 128;

        wolfssl.CTX_SetMinDhKey_Sz(ctx, minDhKey);
        Console.Write("Setting cipher suite to ");
        StringBuilder set_cipher = new StringBuilder("DHE-PSK-AES128-CBC-SHA256");

        Console.WriteLine(set_cipher);
        if (wolfssl.CTX_set_cipher_list(ctx, set_cipher) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Failed to set cipher suite");
            wolfssl.CTX_free(ctx);
            return;
        }

        IPAddress  ip  = IPAddress.Parse("0.0.0.0");
        UdpClient  udp = new UdpClient(11111);
        IPEndPoint ep  = new IPEndPoint(ip, 11111);

        Console.WriteLine("Started UDP and waiting for a connection");

        ssl = wolfssl.new_ssl(ctx);
        if (ssl == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ssl object");
            udp.Close();
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.SetTmpDH_file(ssl, dhparam, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting dhparam");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.set_dtls_fd(ssl, udp, ep) != wolfssl.SUCCESS)
        {
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
        {
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* get connection information and print ip - port */
        wolfssl.DTLS_con con = wolfssl.get_dtls_fd(ssl);
        Console.Write("Connected to ip ");
        Console.Write(con.ep.Address.ToString());
        Console.Write(" on port ");
        Console.WriteLine(con.ep.Port.ToString());

        /* read information sent and send a reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error reading message");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error writing message");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        Console.WriteLine("At the end freeing stuff");
        wolfssl.shutdown(ssl);
        udp.Close();
        clean(ssl, ctx);
    }
Пример #6
0
    public static void Main(string[] args)
    {
        IntPtr ctx;
        IntPtr ssl;

        /* These paths should be changed according to use */
        string fileCert = @"server-cert.pem";
        string fileKey = @"server-key.pem";
        StringBuilder dhparam = new StringBuilder("dh2048.pem");

        wolfssl.psk_delegate psk_cb = new wolfssl.psk_delegate(my_psk_server_cb);

        StringBuilder buff = new StringBuilder(1024);
        StringBuilder reply = new StringBuilder("Hello, this is the wolfSSL C# wrapper");

        wolfssl.Init();

        Console.WriteLine("Calling ctx Init from wolfSSL");
        ctx = wolfssl.CTX_dtls_new(wolfssl.useDTLSv1_2_server());
        if (ctx == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ctx structure");
            return;
        }

        Console.WriteLine("Finished init of ctx .... now load in cert and key");

        if (!File.Exists(fileCert) || !File.Exists(fileKey))
        {
            Console.WriteLine("Could not find cert or key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_certificate_file(ctx, fileCert, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting cert file");
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.CTX_use_PrivateKey_file(ctx, fileKey, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting key file");
            wolfssl.CTX_free(ctx);
            return;
        }

        /* Test psk use with DHE */
        StringBuilder hint = new StringBuilder("cyassl server");
        if (wolfssl.CTX_use_psk_identity_hint(ctx, hint) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error setting hint");
            wolfssl.CTX_free(ctx);
            return;
        }
        wolfssl.CTX_set_psk_server_callback(ctx, psk_cb);

        short minDhKey = 128;
        wolfssl.CTX_SetMinDhKey_Sz(ctx, minDhKey);
        Console.Write("Setting cipher suite to ");
        StringBuilder set_cipher = new StringBuilder("DHE-PSK-AES128-CBC-SHA256");
        Console.WriteLine(set_cipher);
        if (wolfssl.CTX_set_cipher_list(ctx, set_cipher) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Failed to set cipher suite");
            wolfssl.CTX_free(ctx);
            return;
        }

        IPAddress ip = IPAddress.Parse("0.0.0.0");
        UdpClient udp = new UdpClient(11111);
        IPEndPoint ep = new IPEndPoint(ip, 11111);
        Console.WriteLine("Started UDP and waiting for a connection");

        ssl = wolfssl.new_ssl(ctx);
        if (ssl == IntPtr.Zero)
        {
            Console.WriteLine("Error creating ssl object");
            udp.Close();
            wolfssl.CTX_free(ctx);
            return;
        }

        if (wolfssl.SetTmpDH_file(ssl, dhparam, wolfssl.SSL_FILETYPE_PEM) != wolfssl.SUCCESS)
        {
            Console.WriteLine("Error in setting dhparam");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.set_dtls_fd(ssl, udp, ep) != wolfssl.SUCCESS)
        {
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        if (wolfssl.accept(ssl) != wolfssl.SUCCESS)
        {
           Console.WriteLine(wolfssl.get_error(ssl));
           udp.Close();
           clean(ssl, ctx);
           return;
        }

        /* print out results of TLS/SSL accept */
        Console.WriteLine("SSL version is " + wolfssl.get_version(ssl));
        Console.WriteLine("SSL cipher suite is " + wolfssl.get_current_cipher(ssl));

        /* get connection information and print ip - port */
        wolfssl.DTLS_con con = wolfssl.get_dtls_fd(ssl);
        Console.Write("Connected to ip ");
        Console.Write(con.ep.Address.ToString());
        Console.Write(" on port ");
        Console.WriteLine(con.ep.Port.ToString());

        /* read information sent and send a reply */
        if (wolfssl.read(ssl, buff, 1023) < 0)
        {
            Console.WriteLine("Error reading message");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }
        Console.WriteLine(buff);

        if (wolfssl.write(ssl, reply, reply.Length) != reply.Length)
        {
            Console.WriteLine("Error writing message");
            Console.WriteLine(wolfssl.get_error(ssl));
            udp.Close();
            clean(ssl, ctx);
            return;
        }

        Console.WriteLine("At the end freeing stuff");
        wolfssl.shutdown(ssl);
        udp.Close();
        clean(ssl, ctx);
    }