DTLS 1.3 client and server examples

- Basic client
- Basic single-thread single-connection server
- Basic single-thread multiple-connection server using libevent

Compile wolfSSL with `./configure --enable-dtls --enable-dtls13 --enable-hrrcookie`.
Statelessness of server-dtls13-event tested by sending packets found in `dtls/bin-msgs` (`cat dtls/bin-msgs/CH1.bin | nc -u 127.0.0.1 11111 > /dev/null`)
pull/323/head
Juliusz Sosinowicz 2022-06-24 10:41:12 +02:00
parent 3235a2d475
commit c7898d3195
7 changed files with 136 additions and 90 deletions

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@ -127,9 +127,16 @@ int main (int argc, char** argv)
goto cleanup;
}
showConnInfo(ssl);
/*****************************************************************************/
/* Code for sending datagram to server */
if (fgets(sendLine, MAXLINE, stdin) != NULL) {
while (1) {
if (fgets(sendLine, MAXLINE, stdin) == NULL)
break;
if (strncmp(sendLine, "end", 3) == 0)
break;
/* Send sendLine to the server */
if (wolfSSL_write(ssl, sendLine, strlen(sendLine)) != strlen(sendLine)) {

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@ -19,9 +19,6 @@
* 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 client for instructional/learning purposes.
*/
#ifndef DTLS_COMMON_H_
@ -29,45 +26,9 @@
#define INVALID_SOCKET (-1)
#define SFD_TIMEOUT_E (-1)
#define SFD_SOCKET_E (-2)
#define SFD_SELECT_E (-3)
int wait_sfd(SOCKET_T socketfd, int to, int rx) {
fd_set fds, errfds;
fd_set* recvfds = NULL;
fd_set* sendfds = NULL;
SOCKET_T nfds = socketfd + 1;
struct timeval timeout;
int result;
memset(&timeout, 0, sizeof(timeout));
timeout.tv_sec = to;
FD_ZERO(&fds);
FD_SET(socketfd, &fds);
FD_ZERO(&errfds);
FD_SET(socketfd, &errfds);
if (rx)
recvfds = &fds;
else
sendfds = &fds;
result = select(nfds, recvfds, sendfds, &errfds, &timeout);
if (result == 0)
return SFD_TIMEOUT_E;
else if (result > 0) {
if (FD_ISSET(socketfd, &fds)) {
return 0;
}
else if(FD_ISSET(socketfd, &errfds))
return SFD_SOCKET_E;
}
perror("select()");
return SFD_SELECT_E;
void showConnInfo(WOLFSSL* ssl) {
printf("New connection established using %s %s\n",
wolfSSL_get_version(ssl), wolfSSL_get_cipher(ssl));
}

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@ -175,25 +175,27 @@ int main(int argc, char** argv)
printf("SSL_accept failed.\n");
break;
}
if ((recvLen = wolfSSL_read(ssl, buff, sizeof(buff)-1)) > 0) {
printf("heard %d bytes\n", recvLen);
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;
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");
goto error;
}
}
if (wolfSSL_write(ssl, ack, sizeof(ack)) < 0) {
printf("wolfSSL_write fail.\n");
goto error;
}
else {
printf("Sending reply.\n");
}
}
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);
@ -207,8 +209,7 @@ int main(int argc, char** argv)
printf("Client left cont to idle state\n");
}
/* With the "continue" keywords, it is possible for the loop to exit *
* without changing the value of cont */
error:
if (cleanup == 1) {
wolfSSL_set_fd(ssl, 0);
wolfSSL_shutdown(ssl);

View File

@ -35,6 +35,7 @@
#include <netinet/in.h> /* used for sockaddr_in */
#include <arpa/inet.h>
#include <wolfssl/ssl.h>
#include <wolfssl/error-ssl.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
@ -49,10 +50,11 @@
#define QUICK_MULT 4 /* Our quick timeout multiplier */
#define CHGOODCB_E (-1000) /* An error outside the range of wolfSSL
* errors */
#define CONN_TIMEOUT 5 /* How long we wait for peer data before
#define CONN_TIMEOUT 10 /* How long we wait for peer data before
* closing the connection */
typedef struct conn_ctx {
struct conn_ctx* next;
WOLFSSL* ssl;
struct event* readEv;
struct event* writeEv;
@ -63,14 +65,18 @@ WOLFSSL_CTX* ctx = NULL;
struct event_base* base = NULL;
WOLFSSL* pendingSSL = NULL;
int listenfd = INVALID_SOCKET; /* Initialize our socket */
conn_ctx* active = NULL;
struct event* newConnEvent = NULL;
static void sig_handler(const int sig);
static void free_resources(void);
static void newConn(evutil_socket_t fd, short events, void* arg);
static void dataReady(evutil_socket_t fd, short events, void* arg);
static int chGoodCb(WOLFSSL* ssl, void*);
static int hsDoneCb(WOLFSSL* ssl, void*);
static int newPendingSSL(void);
static int newFD(void);
static void conn_ctx_free(conn_ctx* connCtx);
int main(int argc, char** argv)
{
@ -79,7 +85,6 @@ int main(int argc, char** argv)
char servCertLoc[] = "../certs/server-cert.pem";
char servKeyLoc[] = "../certs/server-key.pem";
int exitVal = 1;
struct event* newConnEvent = NULL;
/* Initialize wolfSSL before assigning ctx */
if (wolfSSL_Init() != WOLFSSL_SUCCESS) {
@ -206,24 +211,44 @@ cleanup:
static int newPendingSSL(void)
{
/* Applications should update this secret periodically */
char *secret = "My secret";
WOLFSSL* ssl;
/* Create the pending WOLFSSL Object */
if ((pendingSSL = wolfSSL_new(ctx)) == NULL) {
if ((ssl = wolfSSL_new(ctx)) == NULL) {
fprintf(stderr, "wolfSSL_new error.\n");
return 0;
}
wolfSSL_dtls_set_using_nonblock(pendingSSL, 1);
wolfSSL_dtls_set_using_nonblock(ssl, 1);
if (wolfSSL_SetChGoodCb(pendingSSL, chGoodCb, NULL) != WOLFSSL_SUCCESS ) {
if (wolfSSL_SetChGoodCb(ssl, chGoodCb, NULL) != WOLFSSL_SUCCESS ) {
fprintf(stderr, "wolfSSL_SetChGoodCb error.\n");
wolfSSL_free(ssl);
return 0;
}
if (wolfSSL_set_fd(pendingSSL, listenfd) != WOLFSSL_SUCCESS) {
fprintf(stderr, "wolfSSL_set_fd error.\n");
if (wolfSSL_SetHsDoneCb(ssl, hsDoneCb, NULL) != WOLFSSL_SUCCESS ) {
fprintf(stderr, "wolfSSL_SetHsDoneCb error.\n");
wolfSSL_free(ssl);
return 0;
}
if (wolfSSL_set_fd(ssl, listenfd) != WOLFSSL_SUCCESS) {
fprintf(stderr, "wolfSSL_set_fd error.\n");
wolfSSL_free(ssl);
return 0;
}
if (wolfSSL_send_hrr_cookie(ssl, (byte*)secret, strlen(secret)) != WOLFSSL_SUCCESS) {
fprintf(stderr, "wolfSSL_set_fd error.\n");
wolfSSL_free(ssl);
return 0;
}
pendingSSL = ssl;
return 1;
}
@ -281,28 +306,26 @@ static int chGoodCb(WOLFSSL* ssl, void* arg)
int fd = INVALID_SOCKET;
struct sockaddr_in cliaddr; /* the client's address */
socklen_t cliLen = sizeof(cliaddr);
conn_ctx* new_ctx = (conn_ctx*)calloc(1, sizeof(conn_ctx));
conn_ctx* connCtx = (conn_ctx*)calloc(1, sizeof(conn_ctx));
int timeout = wolfSSL_dtls_get_current_timeout(ssl);
struct timeval tv;
(void)arg;
if (new_ctx == NULL) {
if (connCtx == NULL) {
fprintf(stderr, "Out of memory!\n");
goto error;
}
new_ctx->ssl = ssl;
/* Push to active connection stack */
connCtx->next = active;
active = connCtx;
if (wolfSSL_dtls_get_peer(ssl, &cliaddr, &cliLen) != WOLFSSL_SUCCESS) {
fprintf(stderr, "wolfSSL_dtls_get_peer failed\n");
goto error;
}
/* Promote the pending connection to an active connection */
if (!newPendingSSL())
goto error;
/* We need to change the sfd here so that the ssl object doesn't drop any
* new connections */
fd = newFD();
@ -327,13 +350,13 @@ static int chGoodCb(WOLFSSL* ssl, void* arg)
goto error;
}
new_ctx->writeEv = event_new(base, fd, EV_WRITE, dataReady, new_ctx);
if (new_ctx->writeEv == NULL) {
connCtx->writeEv = event_new(base, fd, EV_WRITE, dataReady, connCtx);
if (connCtx->writeEv == NULL) {
fprintf(stderr, "event_new failed for srvEvent\n");
goto error;
}
new_ctx->readEv = event_new(base, fd, EV_READ, dataReady, new_ctx);
if (new_ctx->readEv == NULL) {
connCtx->readEv = event_new(base, fd, EV_READ, dataReady, connCtx);
if (connCtx->readEv == NULL) {
fprintf(stderr, "event_new failed for srvEvent\n");
goto error;
}
@ -348,21 +371,37 @@ static int chGoodCb(WOLFSSL* ssl, void* arg)
tv.tv_sec = timeout;
/* We are using non-blocking sockets so we will definitely be waiting for
* the peer. Start the timer now. */
if (event_add(new_ctx->readEv, &tv) != 0) {
if (event_add(connCtx->readEv, &tv) != 0) {
fprintf(stderr, "event_add failed\n");
goto error;
}
/* Promote the pending connection to an active connection */
if (!newPendingSSL())
goto error;
connCtx->ssl = ssl;
return 0;
error:
if (fd != INVALID_SOCKET) {
close(fd);
fd = INVALID_SOCKET;
}
if (connCtx != NULL) {
connCtx->ssl = NULL;
conn_ctx_free(connCtx);
}
(void)wolfSSL_set_fd(ssl, INVALID_SOCKET);
return CHGOODCB_E;
}
static int hsDoneCb(WOLFSSL* ssl, void* arg)
{
showConnInfo(ssl);
(void)arg;
return 0;
}
static void dataReady(evutil_socket_t fd, short events, void* arg)
{
conn_ctx* connCtx = (conn_ctx*)arg;
@ -400,7 +439,7 @@ static void dataReady(evutil_socket_t fd, short events, void* arg)
if (connCtx->waitingOnData) {
/* Too long waiting for peer data. Shutdown the connection.
* Don't wait for a response from the peer. */
printf("Closing connection after timeout");
printf("Closing connection after timeout\n");
(void)wolfSSL_shutdown(connCtx->ssl);
goto error;
}
@ -476,18 +515,41 @@ static void dataReady(evutil_socket_t fd, short events, void* arg)
return;
error:
/* Free the connection */
(void)event_del(connCtx->readEv);
(void)event_del(connCtx->writeEv);
event_free(connCtx->readEv); /* EV_PERSIST not used so safe to free here */
event_free(connCtx->writeEv); /* EV_PERSIST not used so safe to free here */
wolfSSL_Free(connCtx->ssl);
conn_ctx_free(connCtx);
close(fd);
free(connCtx);
}
static void conn_ctx_free(conn_ctx* connCtx)
{
if (connCtx != NULL) {
/* Remove from active stack */
if (active != NULL) {
conn_ctx** prev = &active;
while (*prev != NULL) {
if (*prev == connCtx) {
*prev = connCtx->next;
break;
}
prev = &(*prev)->next;
}
}
if (connCtx->ssl != NULL)
wolfSSL_free(connCtx->ssl);
if (connCtx->readEv != NULL) {
(void)event_del(connCtx->readEv);
event_free(connCtx->readEv);
}
if (connCtx->writeEv != NULL) {
(void)event_del(connCtx->writeEv);
event_free(connCtx->writeEv);
}
free(connCtx);
}
}
void sig_handler(const int sig)
{
(void)sig;
printf("Received signal %d. Cleaning up.\n", sig);
free_resources();
wolfSSL_Cleanup();
exit(0);
@ -495,6 +557,12 @@ void sig_handler(const int sig)
void free_resources(void)
{
conn_ctx* connCtx = active;
while (connCtx != NULL) {
active = active->next;
conn_ctx_free(connCtx);
connCtx = active;
}
if (pendingSSL != NULL) {
wolfSSL_shutdown(pendingSSL);
wolfSSL_free(pendingSSL);
@ -508,4 +576,13 @@ void free_resources(void)
close(listenfd);
listenfd = INVALID_SOCKET;
}
if (newConnEvent != NULL) {
(void)event_del(newConnEvent);
event_free(newConnEvent);
newConnEvent = NULL;
}
if (base != NULL) {
event_base_free(base);
base = NULL;
}
}

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@ -158,7 +158,7 @@ int main(int argc, char** argv)
fprintf(stderr, "SSL_accept failed.\n");
goto cleanup;
}
printf("Connected!\n");
showConnInfo(ssl);
if ((recvLen = wolfSSL_read(ssl, buff, sizeof(buff)-1)) > 0) {
printf("heard %d bytes\n", recvLen);