/* server-dtls13.c * * Copyright (C) 2006-2024 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 1.3 server for instructional/learning purposes. * This example can only accept one connection at a time. * * Define USE_DTLS12 to use DTLS 1.2 instead of DTLS 1.3 */ #ifndef WOLFSSL_USER_SETTINGS #include #endif #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 #include #include "dtls-common.h" WOLFSSL_CTX* ctx = NULL; WOLFSSL* ssl = NULL; int listenfd = INVALID_SOCKET; /* Initialize our socket */ static void sig_handler(const int sig); static void free_resources(void); int main(int argc, char** argv) { /* Loc short for "location" */ int exitVal = 1; struct sockaddr_in servAddr; /* our server's address */ struct sockaddr_in cliaddr; /* the client's address */ int ret; int err; int recvLen = 0; /* length of message */ socklen_t cliLen; char buff[MAXLINE]; /* the incoming message */ char ack[] = "I hear you fashizzle!\n"; /* Initialize wolfSSL before assigning ctx */ if (wolfSSL_Init() != WOLFSSL_SUCCESS) { fprintf(stderr, "wolfSSL_Init error.\n"); return exitVal; } /* No-op when debugging is not compiled in */ wolfSSL_Debugging_ON(); /* Set ctx to DTLS 1.3 */ if ((ctx = wolfSSL_CTX_new( #ifdef WOLFSSL_DTLS13 wolfDTLSv1_3_server_method() #else wolfDTLSv1_2_server_method() #endif )) == NULL) { fprintf(stderr, "wolfSSL_CTX_new error.\n"); goto cleanup; } /* Load CA certificates */ if (wolfSSL_CTX_load_verify_locations(ctx,caCertLoc,0) != WOLFSSL_SUCCESS) { fprintf(stderr, "Error loading %s, please check the file.\n", caCertLoc); goto cleanup; } /* Load server certificates */ if (wolfSSL_CTX_use_certificate_file(ctx, servCertLoc, WOLFSSL_FILETYPE_PEM) != WOLFSSL_SUCCESS) { fprintf(stderr, "Error loading %s, please check the file.\n", servCertLoc); goto cleanup; } /* Load server Keys */ if (wolfSSL_CTX_use_PrivateKey_file(ctx, servKeyLoc, WOLFSSL_FILETYPE_PEM) != WOLFSSL_SUCCESS) { fprintf(stderr, "Error loading %s, please check the file.\n", servKeyLoc); goto cleanup; } /* Create a UDP/IP socket */ if ((listenfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) { perror("socket()"); goto cleanup; } printf("Socket allocated\n"); 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); /* Bind Socket */ if (bind(listenfd, (struct sockaddr*)&servAddr, sizeof(servAddr)) < 0) { perror("bind()"); goto cleanup; } signal(SIGINT, sig_handler); while (1) { printf("Awaiting client connection on port %d\n", SERV_PORT); cliLen = sizeof(cliaddr); ret = (int)recvfrom(listenfd, (char *)&buff, sizeof(buff), MSG_PEEK, (struct sockaddr*)&cliaddr, &cliLen); if (ret < 0) { perror("recvfrom()"); goto cleanup; } else if (ret == 0) { fprintf(stderr, "recvfrom zero return\n"); goto cleanup; } /* Create the WOLFSSL Object */ if ((ssl = wolfSSL_new(ctx)) == NULL) { fprintf(stderr, "wolfSSL_new error.\n"); goto cleanup; } if (wolfSSL_dtls_set_peer(ssl, &cliaddr, cliLen) != WOLFSSL_SUCCESS) { fprintf(stderr, "wolfSSL_dtls_set_peer error.\n"); goto cleanup; } if (wolfSSL_set_fd(ssl, listenfd) != WOLFSSL_SUCCESS) { fprintf(stderr, "wolfSSL_set_fd error.\n"); break; } if (wolfSSL_accept(ssl) != WOLFSSL_SUCCESS) { err = wolfSSL_get_error(ssl, 0); fprintf(stderr, "error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err)); fprintf(stderr, "SSL_accept failed.\n"); goto cleanup; } showConnInfo(ssl); 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) { err = wolfSSL_get_error(ssl, 0); if (err == WOLFSSL_ERROR_ZERO_RETURN) /* Received shutdown */ break; fprintf(stderr, "error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err)); fprintf(stderr, "SSL_read failed.\n"); goto cleanup; } printf("Sending reply.\n"); if (wolfSSL_write(ssl, ack, sizeof(ack)) < 0) { err = wolfSSL_get_error(ssl, 0); fprintf(stderr, "error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err)); fprintf(stderr, "wolfSSL_write failed.\n"); goto cleanup; } } printf("reply sent \"%s\"\n", ack); /* Attempt a full shutdown */ ret = wolfSSL_shutdown(ssl); if (ret == WOLFSSL_SHUTDOWN_NOT_DONE) ret = wolfSSL_shutdown(ssl); if (ret != WOLFSSL_SUCCESS) { err = wolfSSL_get_error(ssl, 0); fprintf(stderr, "err = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err)); fprintf(stderr, "wolfSSL_shutdown failed\n"); } wolfSSL_free(ssl); ssl = NULL; printf("Awaiting new connection\n"); } exitVal = 0; cleanup: free_resources(); wolfSSL_Cleanup(); return exitVal; } static void sig_handler(const int sig) { (void)sig; free_resources(); wolfSSL_Cleanup(); } static void free_resources(void) { if (ssl != NULL) { wolfSSL_shutdown(ssl); wolfSSL_free(ssl); ssl = NULL; } if (ctx != NULL) { wolfSSL_CTX_free(ctx); ctx = NULL; } if (listenfd != INVALID_SOCKET) { close(listenfd); listenfd = INVALID_SOCKET; } }