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wolfssl-examples/psk/server-psk-nonblocking.c

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/* server-psk-nonblocking.c
* A server ecample using a TCP connection with PSK security and non blocking.
*
* This file is part of CyaSSL.
*
* CyaSSL 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.
*
* CyaSSL 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
*/
#include <cyassl/ssl.h> /* include cyassl security */
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
#include <signal.h>
#include <fcntl.h> /* needed for runing nonblocking connections */
#include <time.h> /* for time out on read loop */
#define MAXLINE 4096
#define LISTENQ 1024
#define SERV_PORT 11111
/* states of the tcp connection */
enum{
TEST_SELECT_FAIL,
TEST_TIMEOUT,
TEST_RECV_READY,
TEST_ERROR_READY
};
/*
* Pulled in from cyassl/test.h
* Select the tcp, used when nonblocking. Checks the status of the connection.
*/
int tcp_select(int sockfd, int to_sec)
{
fd_set recvfds, errfds;
int nfds = sockfd + 1;
struct timeval timeout = {to_sec, 0};
int result;
/* reset socket values */
FD_ZERO(&recvfds);
FD_SET(sockfd, &recvfds);
FD_ZERO(&errfds);
FD_SET(sockfd, &errfds);
result = select(nfds, &recvfds, NULL, &errfds, &timeout);
/* logic for which enumerated value is returned */
if (result == 0)
return TEST_TIMEOUT;
else if (result > 0) {
if (FD_ISSET(sockfd, &recvfds))
return TEST_RECV_READY;
else if (FD_ISSET(sockfd, &errfds))
return TEST_ERROR_READY;
}
return TEST_SELECT_FAIL;
}
/*
* Pulled in from examples/server/server.c
* Function to handle nonblocking. Loops until tcp_select notifies that it's
* ready for action.
*/
int NonBlockingSSL(CYASSL* ssl)
{
int ret;
int error;
int select_ret;
int sockfd = CyaSSL_get_fd(ssl);
ret = CyaSSL_accept(ssl);
error = CyaSSL_get_error(ssl, 0);
while (ret != SSL_SUCCESS && (error == SSL_ERROR_WANT_READ ||
error == SSL_ERROR_WANT_WRITE)) {
int currTimeout = 1;
/* print out for user notification */
if (error == SSL_ERROR_WANT_READ)
printf("... server would read block\n");
else
printf("... server would write block\n");
select_ret = tcp_select(sockfd, currTimeout);
/* if tcp_select signals ready try to accept otherwise continue loop*/
if ((select_ret == TEST_RECV_READY) ||
(select_ret == TEST_ERROR_READY)) {
ret = CyaSSL_accept(ssl);
error = CyaSSL_get_error(ssl, 0);
}
else if (select_ret == TEST_TIMEOUT) {
error = SSL_ERROR_WANT_READ;
}
else {
error = SSL_FATAL_ERROR;
}
}
/* faliure to accept */
if (ret != SSL_SUCCESS) {
printf("Fatal error : SSL_accept failed\n");
ret = SSL_FATAL_ERROR;
}
return ret;
}
/*
* Handles response to client.
*/
int respond(CYASSL* ssl)
{
int n; /* length of string read */
char buf[MAXLINE]; /* string read from client */
char response[] = "I hear ya for shizzle";
memset(buf, 0, MAXLINE);
do {
if (NonBlockingSSL(ssl) != SSL_SUCCESS)
return 1;
n = CyaSSL_read(ssl, buf, MAXLINE);
if (n > 0) {
printf("%s\n", buf);
}
}
while(n < 0);
if (NonBlockingSSL(ssl) != SSL_SUCCESS)
return 1;
if (CyaSSL_write(ssl, response, strlen(response)) != strlen(response)) {
printf("Fatal error : respond: write error\n");
return 1;
}
return 0;
}
/*
* Used for finding psk value.
*/
static inline unsigned int my_psk_server_cb(CYASSL* ssl, const char* identity,
unsigned char* key, unsigned int key_max_len)
{
(void)ssl;
(void)key_max_len;
if (strncmp(identity, "Client_identity", 15) != 0)
return 0;
key[0] = 26;
key[1] = 43;
key[2] = 60;
key[3] = 77;
return 4;
}
int main()
{
int listenfd, connfd;
int opt;
struct sockaddr_in cliAddr, servAddr;
char buff[MAXLINE];
socklen_t cliLen;
CYASSL_CTX* ctx;
CyaSSL_Init();
if ((ctx = CyaSSL_CTX_new(CyaSSLv23_server_method())) == NULL) {
printf("Fatal error : CyaSSL_CTX_new error\n");
return 1;
}
/* use psk suite for security */
CyaSSL_CTX_set_psk_server_callback(ctx, my_psk_server_cb);
CyaSSL_CTX_use_psk_identity_hint(ctx, "cyassl server");
if (CyaSSL_CTX_set_cipher_list(ctx, "PSK-AES128-CBC-SHA256")
!= SSL_SUCCESS)
printf("Fatal error : server can't set cipher list\n");
/* find a socket */
listenfd = socket(AF_INET, SOCK_STREAM, 0);
if (listenfd < 0) {
printf("Fatal error : socket error\n");
return 1;
}
/* set up server address and port */
memset(&servAddr, 0, sizeof(servAddr));
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
servAddr.sin_port = htons(SERV_PORT);
/* bind to a socket */
opt = 1;
if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, (const void*)&opt,
sizeof(int)) != 0) {
printf("Fatal error : setsockopt errer");
return 1;
}
if (bind(listenfd, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0) {
printf("Fatal error : bind error\n");
return 1;
}
/* main loop for accepting and responding to clients */
for ( ; ; ) {
CYASSL* ssl;
/* listen to the socket */
if (listen(listenfd, LISTENQ) < 0) {
printf("Fatal error : listen error\n");
return 1;
}
cliLen = sizeof(cliAddr);
connfd = accept(listenfd, (struct sockaddr *) &cliAddr, &cliLen);
if (connfd < 0) {
if (errno != EINTR) {
printf("Fatal error : accept error\n");
return 1;
}
}
else {
printf("Connection from %s, port %d\n",
inet_ntop(AF_INET, &cliAddr.sin_addr, buff, sizeof(buff)),
ntohs(cliAddr.sin_port));
/* create CYASSL object */
if ((ssl = CyaSSL_new(ctx)) == NULL) {
printf("Fatal error : CyaSSL_new error\n");
return 1;
}
CyaSSL_set_fd(ssl, connfd);
/* set CyaSSL and socket to non blocking and respond */
CyaSSL_set_using_nonblock(ssl, 1);
if (fcntl(connfd, F_SETFL, O_NONBLOCK) < 0) {
printf("Fatal error : fcntl set failed\n");
return 1;
}
if (respond(ssl) != 0)
printf("Fatal error : respond error\n");
return 1;
/* closes the connections after responding */
CyaSSL_shutdown(ssl);
CyaSSL_free(ssl);
if (close(connfd) == -1) {
printf("Fatal error : close error\n");
return 1;
}
}
}
/* free up memory used by cyassl */
CyaSSL_CTX_free(ctx);
CyaSSL_Cleanup();
return 0;
}
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