/* server-dtls.c * * Copyright (C) 2006-2020 wolfSSL Inc. * * This file is part of wolfSSL. (formerly known as CyaSSL) * * 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 02110-1301, USA * *============================================================================= * * Bare-bones example of a DTLS server for instructional/learning purposes. * Utilizes DTLS 1.2. */ #include #include #include /* standard in/out procedures */ #include /* defines system calls */ #include /* necessary for memset */ #include #include /* used for all socket calls */ #include /* used for sockaddr_in */ #include #include #include #include #define SERV_PORT 11111 /* define our server port number */ #define MSGLEN 4096 static int cleanup = 0; /* To handle shutdown */ static struct sockaddr_in servAddr; /* our server's address */ static struct sockaddr_in cliaddr; /* the client's address */ void sig_handler(const int sig); int main(int argc, char** argv) { /* Loc short for "location" */ char caCertLoc[] = "../certs/ca-cert.pem"; char servCertLoc[] = "../certs/server-cert.pem"; char servKeyLoc[] = "../certs/server-key.pem"; int ret = 0; WOLFSSL_CTX* ctx; /* Variables for awaiting datagram */ int on = 1; int res = 1; int bytesReceived = 0; int recvLen = 0; /* length of message */ int listenfd = 0; /* Initialize our socket */ WOLFSSL* ssl = NULL; socklen_t cliLen; socklen_t len = sizeof(int); unsigned char b[MSGLEN]; /* watch for incoming messages */ char buff[MSGLEN]; /* the incoming message */ char ack[] = "I hear you fashizzle!\n"; /* "./config --enable-debug" and uncomment next line for debugging */ /* wolfSSL_Debugging_ON(); */ /* Initialize wolfSSL */ wolfSSL_Init(); /* Set ctx to DTLS 1.2 */ ctx = wolfSSL_CTX_new(wolfDTLSv1_2_server_method()); if (ctx == NULL) { printf("wolfSSL_CTX_new error.\n"); return 1; } /* Load CA certificates */ ret = wolfSSL_CTX_load_verify_locations(ctx,caCertLoc,0); if (ret != SSL_SUCCESS) { printf("Error loading %s, please check the file.\n", caCertLoc); return 1; } /* Load server certificates */ ret = wolfSSL_CTX_use_certificate_file(ctx, servCertLoc, SSL_FILETYPE_PEM); if (ret != SSL_SUCCESS) { printf("Error loading %s, please check the file.\n", servCertLoc); return 1; } /* Load server Keys */ ret = wolfSSL_CTX_use_PrivateKey_file(ctx, servKeyLoc, SSL_FILETYPE_PEM); if (ret != SSL_SUCCESS) { printf("Error loading %s, please check the file.\n", servKeyLoc); return 1; } /* Await Datagram */ ; while (cleanup != 1) { /* Create a UDP/IP socket */ listenfd = socket(AF_INET, SOCK_DGRAM, 0); if (listenfd <= 0 ) { printf("error: cannot create socket: %d\n", listenfd); break; } printf("info: socket allocated: %d\n", listenfd); /* clear servAddr each loop */ memset((char *)&servAddr, 0, sizeof(servAddr)); /* host-to-network-long conversion (htonl) */ /* host-to-network-short conversion (htons) */ servAddr.sin_family = AF_INET; servAddr.sin_addr.s_addr = htonl(INADDR_ANY); servAddr.sin_port = htons(SERV_PORT); /* Eliminate socket already in use error */ res = setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, len); if (res < 0) { printf("Setsockopt SO_REUSEADDR failed.\n"); break; } /*Bind Socket*/ if (bind(listenfd, (struct sockaddr*)&servAddr, sizeof(servAddr)) < 0) { printf("Bind failed.\n"); break; } printf("Awaiting client connection on port %d\n", SERV_PORT); cliLen = sizeof(cliaddr); bytesReceived = (int)recvfrom(listenfd, (char *)&b, sizeof(b), MSG_PEEK, (struct sockaddr*)&cliaddr, &cliLen); if (bytesReceived < 0) { printf("No clients in que, enter idle state\n"); close(listenfd); continue; } else if (bytesReceived > 0) { if (connect(listenfd, (const struct sockaddr *)&cliaddr, sizeof(cliaddr)) != 0) { printf("Udp connect failed.\n"); break; } } else { printf("Recvfrom failed.\n"); break; } printf("Connected!\n"); /* Create the WOLFSSL Object */ if ((ssl = wolfSSL_new(ctx)) == NULL) { printf("wolfSSL_new error.\n"); break; } #ifdef WOLFSSL_DTLS_SET_PEER /* Alternative to UDP connect */ wolfSSL_dtls_set_peer(ssl, &cliaddr, cliLen); #endif /* set the session ssl to client connection port */ wolfSSL_set_fd(ssl, listenfd); if (wolfSSL_accept(ssl) != SSL_SUCCESS) { int e = wolfSSL_get_error(ssl, 0); printf("error = %d, %s\n", e, wolfSSL_ERR_reason_error_string(e)); printf("SSL_accept failed.\n"); break; } while (1) { if ((recvLen = wolfSSL_read(ssl, buff, sizeof(buff)-1)) > 0) { printf("heard %d bytes\n", recvLen); buff[recvLen] = 0; printf("I heard this: \"%s\"\n", buff); } else if (recvLen < 0) { int readErr = wolfSSL_get_error(ssl, 0); if(readErr != SSL_ERROR_WANT_READ) { printf("SSL_read failed.\n"); break; } } if (wolfSSL_write(ssl, ack, sizeof(ack)) < 0) { printf("wolfSSL_write fail.\n"); break; } else { printf("Sending reply.\n"); } } printf("reply sent \"%s\"\n", ack); wolfSSL_set_fd(ssl, 0); wolfSSL_shutdown(ssl); wolfSSL_free(ssl); close(listenfd); cleanup = 0; printf("Client left cont to idle state\n"); } if (cleanup == 1) { wolfSSL_set_fd(ssl, 0); wolfSSL_shutdown(ssl); wolfSSL_free(ssl); close(listenfd); } wolfSSL_CTX_free(ctx); wolfSSL_Cleanup(); return 0; }