WolfSSL
/
wolfssl-examples
mirror of https://github.com/wolfSSL/wolfssl-examples.git
1
0
Fork 0
Code Issues Releases Wiki Activity
wolfssl-examples/dtls/server-dtls-callback.c

386 lines
12 KiB
C
Raw Blame History

/* server-dtls-callback.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 and custom IO callbacks.
*/
#ifndef WOLFSSL_USER_SETTINGS
#include <wolfssl/options.h>
#endif
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/ssl.h>
#include <stdio.h> /* standard in/out procedures */
#include <stdlib.h> /* defines system calls */
#include <string.h> /* necessary for memset */
#include <netdb.h>
#include <sys/socket.h> /* used for all socket calls */
#include <netinet/in.h> /* used for sockaddr_in */
#include <arpa/inet.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#define SERV_PORT 11111 /* define our server port number */
#define MSGLEN 4096
#define DTLS_MTU 1500
static int cleanup = 0; /* To handle shutdown */
static void sig_handler(const int sig)
{
printf("\nSIGINT %d handled\n", sig);
cleanup = 1;
return;
}
typedef struct SharedDtls {
WOLFSSL* ssl; /* WOLFSSL object being shared */
int sd; /* socket fd */
struct sockaddr_in cliAddr; /* server sockaddr */
socklen_t cliSz; /* length of servAddr */
byte rxBuf[DTLS_MTU];
word32 rxSz;
} SharedDtls;
int my_IORecv(WOLFSSL* ssl, char* buff, int sz, void* ctx)
{
SharedDtls* shared = (SharedDtls*)ctx;
int recvd;
struct sockaddr addr;
socklen_t addrSz = sizeof(addr);
printf("Server Recv fd %d, buf %d\n", shared->sd, sz);
/* handle "peek" rx data */
if (shared->rxSz > 0) {
recvd = shared->rxSz;
if (recvd > sz)
recvd = sz;
memcpy(buff, shared->rxBuf, recvd);
shared->rxSz -= recvd;
memcpy(shared->rxBuf, &shared->rxBuf[recvd], shared->rxSz);
}
else {
/* Receive datagram */
recvd = recvfrom(shared->sd, buff, sz, 0, &addr, &addrSz);
}
if (recvd == -1) {
/* error encountered. Be responsible and report it in wolfSSL terms */
fprintf(stderr, "IO RECEIVE ERROR: %d\n", errno);
switch (errno) {
#if EAGAIN != EWOULDBLOCK
case EAGAIN: /* EAGAIN == EWOULDBLOCK on some systems, but not others */
#endif
case EWOULDBLOCK:
if (!wolfSSL_dtls(ssl) || wolfSSL_get_using_nonblock(ssl)) {
fprintf(stderr, "would block\n");
return WOLFSSL_CBIO_ERR_WANT_READ;
}
else {
fprintf(stderr, "socket timeout\n");
return WOLFSSL_CBIO_ERR_TIMEOUT;
}
case ECONNRESET:
fprintf(stderr, "connection reset\n");
return WOLFSSL_CBIO_ERR_CONN_RST;
case EINTR:
fprintf(stderr, "socket interrupted\n");
cleanup = 1;
return WOLFSSL_CBIO_ERR_GENERAL;
/* NOTE: Don't return WOLFSSL_CBIO_ERR_ISR. It keeps trying to recv */
case ECONNREFUSED:
fprintf(stderr, "connection refused\n");
return WOLFSSL_CBIO_ERR_WANT_READ;
case ECONNABORTED:
fprintf(stderr, "connection aborted\n");
return WOLFSSL_CBIO_ERR_CONN_CLOSE;
default:
fprintf(stderr, "general error\n");
return WOLFSSL_CBIO_ERR_GENERAL;
}
}
else if (recvd == 0) {
printf("Connection closed\n");
return WOLFSSL_CBIO_ERR_CONN_CLOSE;
}
/* successful receive */
printf("my_IORecv: received %d bytes from %d\n", recvd, shared->sd);
return recvd;
}
int my_IOSend(WOLFSSL* ssl, char* buff, int sz, void* ctx)
{
SharedDtls* shared = (SharedDtls*)ctx;
int sent;
const struct sockaddr* addr = NULL;
socklen_t addrSz = 0;
if (shared) {
addr = (const struct sockaddr*)&shared->cliAddr;
addrSz = shared->cliSz;
}
printf("Server Send fd %d, sz %d\n", shared->sd, sz);
/* Send datagram */
sent = sendto(shared->sd, buff, sz, 0, addr, addrSz);
if (sent == -1) {
/* error encountered. Be responsible and report it in wolfSSL terms */
fprintf(stderr, "IO SEND ERROR: %d\n", errno);
switch (errno) {
#if EAGAIN != EWOULDBLOCK
case EAGAIN: /* EAGAIN == EWOULDBLOCK on some systems, but not others */
#endif
case EWOULDBLOCK:
fprintf(stderr, "would block\n");
return WOLFSSL_CBIO_ERR_WANT_READ;
case ECONNRESET:
fprintf(stderr, "connection reset\n");
return WOLFSSL_CBIO_ERR_CONN_RST;
case EINTR:
fprintf(stderr, "socket interrupted\n");
cleanup = 1;
return WOLFSSL_CBIO_ERR_GENERAL;
/* NOTE: Don't return WOLFSSL_CBIO_ERR_ISR. It keeps trying to send */
case EPIPE:
fprintf(stderr, "socket EPIPE\n");
return WOLFSSL_CBIO_ERR_CONN_CLOSE;
default:
fprintf(stderr, "general error\n");
return WOLFSSL_CBIO_ERR_GENERAL;
}
}
else if (sent == 0) {
printf("Connection closed\n");
return 0;
}
/* successful send */
printf("my_IOSend: sent %d bytes to %d\n", sent, shared->sd);
return sent;
}
int main(int argc, char** argv)
{
int ret = 0, err;
const char caCertLoc[] = "../certs/ca-cert.pem";
const char servCertLoc[] = "../certs/server-cert.pem";
const char servKeyLoc[] = "../certs/server-key.pem";
WOLFSSL_CTX* ctx = NULL;
WOLFSSL* ssl = NULL;
char buff[MSGLEN]; /* the incoming message */
int buffLen;
int listenfd = -1; /* Initialize our socket */
int on;
socklen_t len;
SharedDtls shared;
struct sockaddr_in servAddr;
/* Code for handling signals */
struct sigaction act, oact;
act.sa_handler = sig_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
sigaction(SIGINT, &act, &oact);
/* "./config --enable-debug" and uncomment next line for debugging */
wolfSSL_Debugging_ON();
/* Initialize wolfSSL */
wolfSSL_Init();
/* Set ctx to DTLS 1.2 */
if ((ctx = wolfSSL_CTX_new(wolfDTLSv1_2_server_method())) == NULL) {
printf("wolfSSL_CTX_new error.\n");
ret = -1;
goto exit;
}
/* Load CA certificates */
ret = wolfSSL_CTX_load_verify_locations(ctx, caCertLoc, NULL);
if (ret != SSL_SUCCESS) {
printf("Error loading %s, please check the file.\n", caCertLoc);
goto exit;
}
/* 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);
goto exit;
}
/* 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);
goto exit;
}
/* Register callbacks */
wolfSSL_CTX_SetIORecv(ctx, my_IORecv);
wolfSSL_CTX_SetIOSend(ctx, my_IOSend);
/* Await Datagram */
while (cleanup == 0) {
/* Create a UDP/IP socket */
ret = socket(AF_INET, SOCK_DGRAM, 0);
if (ret < 0 ) {
printf("Cannot create socket %d.\n", ret);
goto exit;
}
listenfd = ret;
printf("Socket allocated\n");
/* setup servAddr */
memset(&servAddr, 0, sizeof(servAddr));
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 */
on = 1;
len = sizeof(on);
ret = setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, len);
if (ret < 0) {
printf("Setsockopt SO_REUSEADDR failed %d.\n", errno);
goto exit;
}
/* Bind Socket */
ret = bind(listenfd, (struct sockaddr*)&servAddr, sizeof(servAddr));
if (ret < 0) {
printf("Bind failed %d.\n", errno);
goto exit;
}
printf("Awaiting client connection on port %d\n", SERV_PORT);
memset(&shared, 0, sizeof(shared));
shared.sd = listenfd;
shared.cliSz = sizeof(shared.cliAddr);
ret = (int)recvfrom(listenfd, (char*)shared.rxBuf, sizeof(shared.rxBuf), 0,
(struct sockaddr*)&shared.cliAddr, &shared.cliSz);
if (ret < 0) {
printf("No clients in queue, enter idle state\n");
continue;
}
else if (ret > 0) {
shared.rxSz = ret;
ret = 0;
printf("Connected!\n");
}
else {
printf("Recvfrom failed %d.\n", errno);
break;
}
/* Create the WOLFSSL Object */
if ((ssl = wolfSSL_new(ctx)) == NULL) {
printf("wolfSSL_new error.\n");
break;
}
shared.ssl = ssl;
wolfSSL_SetIOWriteCtx(ssl, &shared);
wolfSSL_SetIOReadCtx(ssl, &shared);
if (wolfSSL_accept(ssl) != SSL_SUCCESS) {
err = wolfSSL_get_error(ssl, 0);
printf("error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err));
printf("SSL_accept failed.\n");
wolfSSL_shutdown(ssl);
wolfSSL_free(ssl);
ssl = NULL;
close(listenfd);
listenfd = -1;
continue;
}
/* echo until shutdown received */
while (cleanup == 0 && ret == 0) {
buffLen = 0;
ret = wolfSSL_read(ssl, buff, sizeof(buff)-1);
if (ret > 0) {
printf("heard %d bytes\n", ret);
buffLen = ret;
buff[buffLen] = '\0';
printf("I heard this: \"%s\"\n", buff);
ret = 0;
}
else {
err = wolfSSL_get_error(ssl, 0);
if (err != SSL_ERROR_WANT_READ) {
printf("error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err));
printf("SSL_read failed.\n");
break;
}
}
printf("Sending echo reply\n");
ret = wolfSSL_write(ssl, buff, buffLen);
if (ret < 0) {
err = wolfSSL_get_error(ssl, 0);
if (err != SSL_ERROR_WANT_WRITE) {
printf("error = %d, %s\n", err, wolfSSL_ERR_reason_error_string(err));
printf("wolfSSL_write fail.\n");
break;
}
}
ret = 0; /* success */
}
wolfSSL_free(ssl);
ssl = NULL;
close(listenfd);
listenfd = -1;
printf("Client done, waiting for next connection\n");
}
exit:
if (ssl) {
wolfSSL_shutdown(ssl);
wolfSSL_free(ssl);
}
if (listenfd != -1) {
close(listenfd);
}
if (ctx) {
wolfSSL_CTX_free(ctx);
}
wolfSSL_Cleanup();
return ret;
}
Reference in New Issue View Git Blame Copy Permalink