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/*
* Copyright (C) 2015 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup examples
* @{
*
* @file
* @brief The cliend side of TinyDTLS (Simple echo)
*
* @author Raul A. Fuentes Samaniego <ra.fuentes.sam+RIOT@gmail.com>
* @author Olaf Bergmann <bergmann@tzi.org>
* @author Hauke Mehrtens <hauke@hauke-m.de>
* @author Oliver Hahm <oliver.hahm@inria.fr>
* @}
*/
#include <stdio.h>
#include <inttypes.h>
#include "net/gnrc.h"
#include "net/gnrc/ipv6.h"
#include "net/gnrc/udp.h"
#include "net/gnrc/pktdump.h"
#include "timex.h"
#include "xtimer.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
/* TinyDTLS */
#include "tinydtls.h"
#include "dtls_debug.h"
#include "dtls.h"
#include "global.h"
/* TODO: Remove the UNUSED_PARAM from TinyDTLS' stack? */
#ifdef __GNUC__
#define UNUSED_PARAM __attribute__((unused))
#else
#define UNUSED_PARAM
#endif /* __GNUC__ */
#ifdef DTLS_PSK
#define PSK_DEFAULT_IDENTITY "Client_identity"
#define PSK_DEFAULT_KEY "secretPSK"
#define PSK_OPTIONS "i:k:"
/* Max size for PSK lowered for embedded devices */
#define PSK_ID_MAXLEN 32
#define PSK_MAXLEN 32
#endif /* DTLS_PSK */
//#define DEFAULT_PORT 20220 /* DTLS default port */
#define DEFAULT_PORT 61618 /* First valid FEBx address */
#define CLIENT_PORT DEFAULT_PORT + 1
#define MAX_TIMES_TRY_TO_SEND 10
static dtls_context_t *dtls_context = NULL;
static char *client_payload;
static size_t buflen = 0;
static const unsigned char ecdsa_priv_key[] = {
0x41, 0xC1, 0xCB, 0x6B, 0x51, 0x24, 0x7A, 0x14,
0x43, 0x21, 0x43, 0x5B, 0x7A, 0x80, 0xE7, 0x14,
0x89, 0x6A, 0x33, 0xBB, 0xAD, 0x72, 0x94, 0xCA,
0x40, 0x14, 0x55, 0xA1, 0x94, 0xA9, 0x49, 0xFA
};
static const unsigned char ecdsa_pub_key_x[] = {
0x36, 0xDF, 0xE2, 0xC6, 0xF9, 0xF2, 0xED, 0x29,
0xDA, 0x0A, 0x9A, 0x8F, 0x62, 0x68, 0x4E, 0x91,
0x63, 0x75, 0xBA, 0x10, 0x30, 0x0C, 0x28, 0xC5,
0xE4, 0x7C, 0xFB, 0xF2, 0x5F, 0xA5, 0x8F, 0x52
};
static const unsigned char ecdsa_pub_key_y[] = {
0x71, 0xA0, 0xD4, 0xFC, 0xDE, 0x1A, 0xB8, 0x78,
0x5A, 0x3C, 0x78, 0x69, 0x35, 0xA7, 0xCF, 0xAB,
0xE9, 0x3F, 0x98, 0x72, 0x09, 0xDA, 0xED, 0x0B,
0x4F, 0xAB, 0xC3, 0x6F, 0xC7, 0x72, 0xF8, 0x29
};
/**
* @brief This care about getting messages and continue with the DTLS flights.
* This will handle all the packets arriving to the node.
* Will determine if its from a new DTLS peer or a previous one.
*/
static void dtls_handle_read(dtls_context_t *ctx, gnrc_pktsnip_t *pkt)
{
static session_t session;
/*
* NOTE: GNRC (Non-socket) issue: we need to modify the current
* DTLS Context for the IPv6 src (and in a future the port src).
*/
/* Taken from the tftp server example */
char addr_str[IPV6_ADDR_MAX_STR_LEN];
gnrc_pktsnip_t *tmp2;
tmp2 = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_IPV6);
ipv6_hdr_t *hdr = (ipv6_hdr_t *)tmp2->data;
ipv6_addr_to_str(addr_str, &hdr->src, sizeof(addr_str));
/*
*TODO: More testings with TinyDTLS is neccesary, but seem this is safe.
*/
tmp2 = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_UDP);
udp_hdr_t *udp = (udp_hdr_t *)tmp2->data;
session.size = sizeof(ipv6_addr_t) + sizeof(unsigned short);
session.port = byteorder_ntohs(udp->src_port);
DEBUG("DBG-Client: Msg received from \n\t Addr Src: %s"
"\n\t Current Peer: %s \n", addr_str, (char *)dtls_get_app_data(ctx));
ipv6_addr_from_str(&session.addr, addr_str);
dtls_handle_message(ctx, &session, pkt->data, (unsigned int)pkt->size);
}
#ifdef DTLS_PSK
static unsigned char psk_id[PSK_ID_MAXLEN] = PSK_DEFAULT_IDENTITY;
static size_t psk_id_length = sizeof(PSK_DEFAULT_IDENTITY) - 1;
static unsigned char psk_key[PSK_MAXLEN] = PSK_DEFAULT_KEY;
static size_t psk_key_length = sizeof(PSK_DEFAULT_KEY) - 1;
/**
* This function is the "key store" for tinyDTLS. It is called to
* retrieve a key for the given identity within this particular
* session.
*/
static int peer_get_psk_info(struct dtls_context_t *ctx UNUSED_PARAM,
const session_t *session UNUSED_PARAM,
dtls_credentials_type_t type,
const unsigned char *id, size_t id_len,
unsigned char *result, size_t result_length)
{
switch (type) {
case DTLS_PSK_IDENTITY:
/* Removed due probably in the motes is useless
if (id_len) {
dtls_debug("got psk_identity_hint: '%.*s'\n", id_len, id);
}
*/
if (result_length < psk_id_length) {
dtls_warn("cannot set psk_identity -- buffer too small\n");
return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
}
memcpy(result, psk_id, psk_id_length);
return psk_id_length;
case DTLS_PSK_KEY:
if (id_len != psk_id_length || memcmp(psk_id, id, id_len) != 0) {
dtls_warn("PSK for unknown id requested, exiting\n");
return dtls_alert_fatal_create(DTLS_ALERT_ILLEGAL_PARAMETER);
}
else if (result_length < psk_key_length) {
dtls_warn("cannot set psk -- buffer too small\n");
return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
}
memcpy(result, psk_key, psk_key_length);
return psk_key_length;
default:
dtls_warn("unsupported request type: %d\n", type);
}
return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
}
#endif /* DTLS_PSK */
#ifdef DTLS_ECC
static int peer_get_ecdsa_key(struct dtls_context_t *ctx,
const session_t *session,
const dtls_ecdsa_key_t **result)
{
(void) ctx;
(void) session;
static const dtls_ecdsa_key_t ecdsa_key = {
.curve = DTLS_ECDH_CURVE_SECP256R1,
.priv_key = ecdsa_priv_key,
.pub_key_x = ecdsa_pub_key_x,
.pub_key_y = ecdsa_pub_key_y
};
*result = &ecdsa_key;
return 0;
}
static int peer_verify_ecdsa_key(struct dtls_context_t *ctx,
const session_t *session,
const unsigned char *other_pub_x,
const unsigned char *other_pub_y,
size_t key_size)
{
(void) ctx;
(void) session;
(void) key_size;
(void) other_pub_x;
(void) other_pub_y;
return 0;
}
#endif /* DTLS_ECC */
/**
* @brief This will try to transmit using only GNRC stack.
* This is basically the original send function from gnrc/networking
*/
static int gnrc_sending(char *addr_str, char *data, size_t data_len )
{
ipv6_addr_t addr;
gnrc_pktsnip_t *payload, *udp, *ip;
/* parse destination address */
if (ipv6_addr_from_str(&addr, addr_str) == NULL) {
puts("Error: unable to parse destination address");
return -1;
}
/* allocate payload */
payload = gnrc_pktbuf_add(NULL, data, data_len, GNRC_NETTYPE_UNDEF);
if (payload == NULL) {
puts("Error: unable to copy data to packet buffer");
return -1;
}
/* allocate UDP header */
udp = gnrc_udp_hdr_build(payload, (uint16_t) CLIENT_PORT, (uint16_t) DEFAULT_PORT);
if (udp == NULL) {
puts("Error: unable to allocate UDP header");
gnrc_pktbuf_release(payload);
return -1;
}
/* allocate IPv6 header */
ip = gnrc_ipv6_hdr_build(udp, NULL, &addr);
if (ip == NULL) {
puts("Error: unable to allocate IPv6 header");
gnrc_pktbuf_release(udp);
return -1;
}
/*
* WARNING: Too fast and the nodes dies in middle of retransmissions.
* This issue appears in the FIT-Lab (m3 motes).
* In native, is not required.
*/
xtimer_usleep(500000);
/* send packet */
if (!gnrc_netapi_dispatch_send(GNRC_NETTYPE_UDP, GNRC_NETREG_DEMUX_CTX_ALL, ip)) {
puts("Error: unable to locate UDP thread");
gnrc_pktbuf_release(ip);
return -1;
}
return 1;
}
/**
* @brief This will print the data read from the Peer.
* THIS AT THE END of the 6 flights (DTLS App Data).
* Is here where we know that the connection has finished.
* TODO: The connected variable could de modified here.
*/
static int read_from_peer(struct dtls_context_t *ctx,
session_t *session, uint8 *data, size_t len)
{
/* Linux and Contiki version are exactly the same. */
(void) session;
(void) ctx;
size_t i;
printf("\n\n Echo received: ");
for (i = 0; i < len; i++)
printf("%c", data[i]);
printf(" \n\n\n");
return 0;
}
/**
* @brief Will try to transmit the next DTLS flight for a speicifc Peer.
* NOTE:The global buff and buflen is used for be able to transmit the
* Payload in segmented datagrams.
*/
static void try_send(struct dtls_context_t *ctx, session_t *dst)
{
int res;
res = dtls_write(ctx, dst, (uint8_t *)client_payload, buflen);
if (res >= 0) {
memmove(client_payload, client_payload + res, buflen - res);
buflen -= res;
}
else {
DEBUG("DBG-Client: dtls_write returned error!\n" );
}
}
/**
* @brief This SIGNAL function will prepare the next DTLS flight to send.
*/
static int send_to_peer(struct dtls_context_t *ctx,
session_t *session, uint8 *buf, size_t len)
{
(void) session;
/*
* For this testing with GNR we are to extract the peer's addresses and
* making the connection from zero.
*/
char *addr_str;
addr_str = (char *)dtls_get_app_data(ctx);
/* TODO: Confirm that indeed len size of data was sent, otherwise
* return the correct number of bytes sent
*/
gnrc_sending(addr_str, (char *)buf, len);
return len;
}
/***
* This is a custom function for preparing the SIGNAL events and
* create a new DTLS context.
*/
static void init_dtls(session_t *dst, char *addr_str)
{
static dtls_handler_t cb = {
.write = send_to_peer,
.read = read_from_peer,
.event = NULL,
#ifdef DTLS_PSK
.get_psk_info = peer_get_psk_info,
#endif /* DTLS_PSK */
#ifdef DTLS_ECC
.get_ecdsa_key = peer_get_ecdsa_key,
.verify_ecdsa_key = peer_verify_ecdsa_key
#endif /* DTLS_ECC */
};
#ifdef DTLS_PSK
puts("Client support PSK");
#endif
#ifdef DTLS_ECC
puts("Client support ECC");
#endif
DEBUG("DBG-Client: Debug ON");
/*
* The objective of ctx->App is be able to retrieve
* enough information for restablishing a connection.
* This is to be used in the send_to_peer and (potentially) the
* read_from_peer, to continue the transmision with the next
* step of the DTLS flights.
* TODO: Take away the DEFAULT_PORT and CLIENT_PORT.
*/
dst->size = sizeof(ipv6_addr_t) + sizeof(unsigned short);
dst->port = (unsigned short) DEFAULT_PORT;
if (ipv6_addr_from_str(&dst->addr, addr_str) == NULL) {
puts("ERROR: init_dtls was unable to load the IPv6 addresses!\n");
dtls_context = NULL;
return;
}
ipv6_addr_t addr_dbg;
ipv6_addr_from_str(&addr_dbg, addr_str);
/*akin to syslog: EMERG, ALERT, CRITC, NOTICE, INFO, DEBUG */
dtls_set_log_level(DTLS_LOG_NOTICE);
dtls_context = dtls_new_context(addr_str);
if (dtls_context) {
dtls_set_handler(dtls_context, &cb);
}
return;
}
/**
* This is the "client" part of this program.
* Will be called each time a message is transmitted.
*/
static void client_send(char *addr_str, char *data, unsigned int delay)
{
int8_t iWatch;
static session_t dst;
static int connected = 0;
msg_t msg;
gnrc_netreg_entry_t entry = GNRC_NETREG_ENTRY_INIT_PID(CLIENT_PORT,
sched_active_pid);
dtls_init();
if (gnrc_netreg_register(GNRC_NETTYPE_UDP, &entry)) {
puts("Unable to register ports");
/*FIXME: Release memory?*/
return;
}
if (strlen(data) > DTLS_MAX_BUF) {
puts("Data too long ");
return;
}
init_dtls(&dst, addr_str);
if (!dtls_context) {
dtls_emerg("cannot create context\n");
puts("Client unable to load context!");
return;
}
/* client_payload is global due to the SIGNAL function send_to_peer */
client_payload = data;
buflen = strlen(client_payload);
iWatch = MAX_TIMES_TRY_TO_SEND;
/*
* dtls_connect is the one who begin all the process.
* However, do it too fast, and the node will attend it before having a
* valid IPv6 or even a route to the destiny (This could be verified as the
* sequence number of the first DTLS Hello message will be greater than
* zero).
*/
//connected = dtls_connect(dtls_context, &dst) >= 0;
/*
* Until all the data is not sent we remains trying to connect to the
* server. Plus a small watchdog.
*/
while ((buflen > 0) && (iWatch > 0)) {
/*
* NOTE: I (rfuentess) personally think this should be until this point
* instead before (that is why the previous dtls_connect is by defualt
* commented..
*/
if (!connected) {
connected = dtls_connect(dtls_context, &dst);
}
else if (connected < 0) {
puts("Client DTLS was unable to establish a channel!\n");
/*NOTE: Not sure what to do in this scenario (if can happens)*/
}
else {
/*TODO: must happens always or only when connected?*/
try_send(dtls_context, &dst);
}
/*
* WARNING: The delay is KEY HERE! Too fast, and we can kill the
* DTLS state machine. Another alternative is change to
* blocking states (making the watchdog useless)
*
* msg_receive(&msg);
*/
xtimer_usleep(delay);
if (msg_try_receive(&msg) == 1) {
dtls_handle_read(dtls_context, (gnrc_pktsnip_t *)(msg.content.ptr));
}
iWatch--;
} /*END while*/
dtls_free_context(dtls_context);
/* unregister our UDP listener on this thread */
gnrc_netreg_unregister(GNRC_NETTYPE_UDP, &entry);
connected = 0; /*Probably this should be removed or global */
/* Permanent or not permanent? */
DEBUG("DTLS-Client: DTLS session finished\n");
}
int udp_client_cmd(int argc, char **argv)
{
uint32_t delay = 1000000;
if (argc < 3) {
printf("usage: %s <addr> <data> [<delay in us>]\n", argv[0]);
return 1;
}
else if (argc > 3) {
delay = atoi(argv[3]);
}
client_send(argv[1], argv[2], delay);
return 0;
}