/* wolfSSL-Example-IOCallbacks.cs * * Copyright (C) 2006-2023 wolfSSL Inc. * * This file is part of wolfSSL. * * wolfSSL is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * wolfSSL is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA */ using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Net; using System.Net.Sockets; using System.Runtime.InteropServices; using System.IO; using wolfSSL.CSharp; class wolfSSL_Example_IOCallbacks { /// /// Example call back to allow receiving TLS information /// /// structure of ssl passed in /// buffer to contain received msg /// size of buffer for receiving /// information passed in from set_fd /// size of message received private static int wolfSSLCbIORecv(IntPtr ssl, IntPtr buf, int sz, IntPtr ctx) { if (sz <= 0) { wolfssl.log(wolfssl.ERROR_LOG, "wolfssl receive error, size less than 0"); return wolfssl.CBIO_ERR_GENERAL; } int amtRecv = 0; try { System.Runtime.InteropServices.GCHandle gch; gch = GCHandle.FromIntPtr(ctx); Socket con = (System.Net.Sockets.Socket)gch.Target; Byte[] msg = new Byte[sz]; amtRecv = con.Receive(msg, msg.Length, 0); Marshal.Copy(msg, 0, buf, sz); } catch (Exception e) { wolfssl.log(wolfssl.ENTER_LOG, "Error in receive " + e.ToString()); return wolfssl.CBIO_ERR_CONN_CLOSE; } Console.WriteLine("Example custom receive got {0:D} bytes", amtRecv); return amtRecv; } /// /// Example call back used for sending TLS information /// /// pointer to ssl struct /// buffer containing information to send /// size of buffer to send /// object that was set as fd /// amount of information sent private static int wolfSSLCbIOSend(IntPtr ssl, IntPtr buf, int sz, IntPtr ctx) { if (sz <= 0) { wolfssl.log(wolfssl.ERROR_LOG, "wolfssl send error, size less than 0"); return wolfssl.CBIO_ERR_GENERAL; } try { System.Runtime.InteropServices.GCHandle gch; gch = GCHandle.FromIntPtr(ctx); Socket con = (System.Net.Sockets.Socket)gch.Target; Byte[] msg = new Byte[sz]; Marshal.Copy(buf, msg, 0, sz); con.Send(msg, 0, msg.Length, SocketFlags.None); Console.WriteLine("Example custom send sent {0:D} bytes", sz); return sz; } catch (Exception e) { wolfssl.log(wolfssl.ERROR_LOG, "socket connection issue " + e.ToString()); return wolfssl.CBIO_ERR_CONN_CLOSE; } } /// /// Example of a PSK function call back /// /// pointer to ssl structure /// identity of client connecting /// buffer to hold key /// max key size /// size of key set public static uint my_psk_server_cb(IntPtr ssl, string identity, IntPtr key, uint max_key) { /* perform a check on the identity sent across * log function must be set for print out of logging information */ wolfssl.log(wolfssl.INFO_LOG, "PSK Client Identity = " + identity); /* Use desired key, note must be a key smaller than max key size parameter Replace this with desired key. Is trivial one for testing */ if (max_key < 4) return 0; byte[] tmp = { 26, 43, 60, 77 }; Marshal.Copy(tmp, 0, key, 4); return (uint)4; } /// /// Example of a certificate verify function /// /// /// pointer to a WOLFSSL_X509_STORE_CTX /// size of key set public static int my_verify_cb(int preverify, IntPtr store) { if (store == IntPtr.Zero) { Console.WriteLine("store is null"); } Console.WriteLine("Status of certificate verify = " + preverify); Console.WriteLine("Error value for cert store is " + wolfssl.X509_STORE_CTX_get_error(store)); /* look at the current cert in store */ try { X509 x509 = wolfssl.X509_STORE_CTX_get_current_cert(store); Console.WriteLine("Issuer : " + x509.Issuer); Console.WriteLine("Subject : " + x509.Subject); Console.WriteLine("PEM of certificate:"); Console.WriteLine(System.Text.Encoding.UTF8.GetString(x509.Export())); Console.WriteLine("DER of certificate:"); Console.WriteLine(BitConverter.ToString(x509.Export(wolfssl.SSL_FILETYPE_ASN1))); Console.WriteLine("Public key:"); Console.WriteLine(BitConverter.ToString(x509.GetPublicKey())); } catch (Exception e) { Console.WriteLine("Unable to get X509's" + e); } /* list all certs in store */ try { int i; X509[] x509 = wolfssl.X509_STORE_CTX_get_certs(store); for (i = 0; i < x509.Length; i++) { Console.WriteLine("CERT[" + i + "]"); Console.WriteLine("Issuer : " + x509[i].Issuer); Console.WriteLine("Subject : " + x509[i].Subject); Console.WriteLine(""); } } catch (Exception e) { Console.WriteLine("Unable to get X509's" + e); } /* by returning 1 here we override any failure and report success */ return preverify; } private static void clean(IntPtr ssl, IntPtr ctx) { wolfssl.free(ssl); wolfssl.CTX_free(ctx); wolfssl.Cleanup(); } static void Main(string[] args) { IntPtr ctx; IntPtr ssl; Socket fd; wolfssl.CallbackVerify_delegate verify_cb = new wolfssl.CallbackVerify_delegate(my_verify_cb); /* These paths should be changed according to use */ string fileCert = wolfssl.setPath("server-cert.pem"); string fileKey = wolfssl.setPath("server-key.pem"); StringBuilder dhparam = new StringBuilder(wolfssl.setPath("dh2048.pem")); if (fileCert == "" || fileKey == "" || dhparam.Length == 0) { Console.WriteLine("Platform not supported"); return; } 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 (!File.Exists(dhparam.ToString())) { Console.WriteLine("Could not find dh 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); } }