/*
* rtpw.c
*
* rtp word sender/receiver
*
* David A. McGrew
* Cisco Systems, Inc.
*
* This app is a simple RTP application intended only for testing
* libsrtp. It reads one word at a time from /usr/dict/words (or
* whatever file is specified as DICT_FILE), and sends one word out
* each USEC_RATE microseconds. Secure RTP protections can be
* applied. See the usage() function for more details.
*
*/
/*
*
* Copyright (c) 2001-2006, Cisco Systems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* Neither the name of the Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "datatypes.h"
#include "getopt_s.h" /* for local getopt() */
#include <stdio.h> /* for printf, fprintf */
#include <stdlib.h> /* for atoi() */
#include <errno.h>
#include <unistd.h> /* for close() */
#include <string.h> /* for strncpy() */
#include <time.h> /* for usleep() */
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#elif defined HAVE_WINSOCK2_H
# include <winsock2.h>
# include <ws2tcpip.h>
# define RTPW_USE_WINSOCK2 1
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#include "srtp.h"
#include "rtp.h"
#ifdef RTPW_USE_WINSOCK2
# define DICT_FILE "words.txt"
#else
# define DICT_FILE "/usr/share/dict/words"
#endif
#define USEC_RATE (5e5)
#define MAX_WORD_LEN 128
#define ADDR_IS_MULTICAST(a) IN_MULTICAST(htonl(a))
#define MAX_KEY_LEN 64
#define MASTER_KEY_LEN 30
#ifndef HAVE_USLEEP
# ifdef HAVE_WINDOWS_H
# define usleep(us) Sleep((us)/1000)
# else
# define usleep(us) sleep((us)/1000000)
# endif
#endif
/*
* the function usage() prints an error message describing how this
* program should be called, then calls exit()
*/
void
usage(char *prog_name);
/*
* leave_group(...) de-registers from a multicast group
*/
void
leave_group(int sock, struct ip_mreq mreq, char *name);
/*
* program_type distinguishes the [s]rtp sender and receiver cases
*/
typedef enum { sender, receiver, unknown } program_type;
int
main (int argc, char *argv[]) {
char *dictfile = DICT_FILE;
FILE *dict;
char word[MAX_WORD_LEN];
int sock, ret;
struct in_addr rcvr_addr;
struct sockaddr_in name;
struct ip_mreq mreq;
#if BEW
struct sockaddr_in local;
#endif
program_type prog_type = unknown;
sec_serv_t sec_servs = sec_serv_none;
unsigned char ttl = 5;
int c;
char *input_key = NULL;
char *address = NULL;
char key[MAX_KEY_LEN];
unsigned short port = 0;
rtp_sender_t snd;
srtp_policy_t policy;
err_status_t status;
int len;
int do_list_mods = 0;
uint32_t ssrc = 0xdeadbeef; /* ssrc value hardcoded for now */
#ifdef RTPW_USE_WINSOCK2
WORD wVersionRequested = MAKEWORD(2, 0);
WSADATA wsaData;
ret = WSAStartup(wVersionRequested, &wsaData);
if (ret != 0) {
fprintf(stderr, "error: WSAStartup() failed: %d\n", ret);
exit(1);
}
#endif
/* initialize srtp library */
status = srtp_init();
if (status) {
printf("error: srtp initialization failed with error code %d\n", status);
exit(1);
}
/* check args */
while (1) {
c = getopt_s(argc, argv, "k:rsaeld:");
if (c == -1) {
break;
}
switch (c) {
case 'k':
input_key = optarg_s;
break;
case 'e':
sec_servs |= sec_serv_conf;
break;
case 'a':
sec_servs |= sec_serv_auth;
break;
case 'r':
prog_type = receiver;
break;
case 's':
prog_type = sender;
break;
case 'd':
status = crypto_kernel_set_debug_module(optarg_s, 1);
if (status) {
printf("error: set debug module (%s) failed\n", optarg_s);
exit(1);
}
break;
case 'l':
do_list_mods = 1;
break;
default:
usage(argv[0]);
}
}
if (prog_type == unknown) {
if (do_list_mods) {
status = crypto_kernel_list_debug_modules();
if (status) {
printf("error: list of debug modules failed\n");
exit(1);
}
return 0;
} else {
printf("error: neither sender [-s] nor receiver [-r] specified\n");
usage(argv[0]);
}
}
if ((sec_servs && !input_key) || (!sec_servs && input_key)) {
/*
* a key must be provided if and only if security services have
* been requested
*/
usage(argv[0]);
}
if (argc != optind_s + 2) {
/* wrong number of arguments */
usage(argv[0]);
}
/* get address from arg */
address = argv[optind_s++];
/* get port from arg */
port = atoi(argv[optind_s++]);
/* set address */
#ifdef HAVE_INET_ATON
if (0 == inet_aton(address, &rcvr_addr)) {
fprintf(stderr, "%s: cannot parse IP v4 address %s\n", argv[0], address);
exit(1);
}
if (rcvr_addr.s_addr == INADDR_NONE) {
fprintf(stderr, "%s: address error", argv[0]);
exit(1);
}
#else
rcvr_addr.s_addr = inet_addr(address);
if (0xffffffff == rcvr_addr.s_addr) {
fprintf(stderr, "%s: cannot parse IP v4 address %s\n", argv[0], address);
exit(1);
}
#endif
/* open socket */
sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (sock < 0) {
int err;
#ifdef RTPW_USE_WINSOCK2
err = WSAGetLastError();
#else
err = errno;
#endif
fprintf(stderr, "%s: couldn't open socket: %d\n", argv[0], err);
exit(1);
}
name.sin_addr = rcvr_addr;
name.sin_family = PF_INET;
name.sin_port = htons(port);
if (ADDR_IS_MULTICAST(rcvr_addr.s_addr)) {
if (prog_type == sender) {
ret = setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, &ttl,
sizeof(ttl));
if (ret < 0) {
fprintf(stderr, "%s: Failed to set TTL for multicast group", argv[0]);
perror("");
exit(1);
}
}
mreq.imr_multiaddr.s_addr = rcvr_addr.s_addr;
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void*)&mreq,
sizeof(mreq));
if (ret < 0) {
fprintf(stderr, "%s: Failed to join multicast group", argv[0]);
perror("");
exit(1);
}
}
/* report security services selected on the command line */
printf("security services: ");
if (sec_servs & sec_serv_conf)
printf("confidentiality ");
if (sec_servs & sec_serv_auth)
printf("message authentication");
if (sec_servs == sec_serv_none)
printf("none");
printf("\n");
/* set up the srtp policy and master key */
if (sec_servs) {
/*
* create policy structure, using the default mechanisms but
* with only the security services requested on the command line,
* using the right SSRC value
*/
switch (sec_servs) {
case sec_serv_conf_and_auth:
crypto_policy_set_rtp_default(&policy.rtp);
crypto_policy_set_rtcp_default(&policy.rtcp);
break;
case sec_serv_conf:
crypto_policy_set_aes_cm_128_null_auth(&policy.rtp);
crypto_policy_set_rtcp_default(&policy.rtcp);
break;
case sec_serv_auth:
crypto_policy_set_null_cipher_hmac_sha1_80(&policy.rtp);
crypto_policy_set_rtcp_default(&policy.rtcp);
break;
default:
printf("error: unknown security service requested\n");
return -1;
}
policy.ssrc.type = ssrc_specific;
policy.ssrc.value = ssrc;
policy.key = (uint8_t *) key;
policy.next = NULL;
policy.window_size = 128;
policy.allow_repeat_tx = 0;
policy.rtp.sec_serv = sec_servs;
policy.rtcp.sec_serv = sec_serv_none; /* we don't do RTCP anyway */
/*
* read key from hexadecimal on command line into an octet string
*/
len = hex_string_to_octet_string(key, input_key, MASTER_KEY_LEN*2);
/* check that hex string is the right length */
if (len < MASTER_KEY_LEN*2) {
fprintf(stderr,
"error: too few digits in key/salt "
"(should be %d hexadecimal digits, found %d)\n",
MASTER_KEY_LEN*2, len);
exit(1);
}
if (strlen(input_key) > MASTER_KEY_LEN*2) {
fprintf(stderr,
"error: too many digits in key/salt "
"(should be %d hexadecimal digits, found %u)\n",
MASTER_KEY_LEN*2, (unsigned)strlen(input_key));
exit(1);
}
printf("set master key/salt to %s/", octet_string_hex_string(key, 16));
printf("%s\n", octet_string_hex_string(key+16, 14));
} else {
/*
* we're not providing security services, so set the policy to the
* null policy
*
* Note that this policy does not conform to the SRTP
* specification, since RTCP authentication is required. However,
* the effect of this policy is to turn off SRTP, so that this
* application is now a vanilla-flavored RTP application.
*/
policy.key = (uint8_t *)key;
policy.ssrc.type = ssrc_specific;
policy.ssrc.value = ssrc;
policy.rtp.cipher_type = NULL_CIPHER;
policy.rtp.cipher_key_len = 0;
policy.rtp.auth_type = NULL_AUTH;
policy.rtp.auth_key_len = 0;
policy.rtp.auth_tag_len = 0;
policy.rtp.sec_serv = sec_serv_none;
policy.rtcp.cipher_type = NULL_CIPHER;
policy.rtcp.cipher_key_len = 0;
policy.rtcp.auth_type = NULL_AUTH;
policy.rtcp.auth_key_len = 0;
policy.rtcp.auth_tag_len = 0;
policy.rtcp.sec_serv = sec_serv_none;
policy.window_size = 0;
policy.allow_repeat_tx = 0;
policy.next = NULL;
}
if (prog_type == sender) {
#if BEW
/* bind to local socket (to match crypto policy, if need be) */
memset(&local, 0, sizeof(struct sockaddr_in));
local.sin_addr.s_addr = htonl(INADDR_ANY);
local.sin_port = htons(port);
ret = bind(sock, (struct sockaddr *) &local, sizeof(struct sockaddr_in));
if (ret < 0) {
fprintf(stderr, "%s: bind failed\n", argv[0]);
perror("");
exit(1);
}
#endif /* BEW */
/* initialize sender's rtp and srtp contexts */
snd = rtp_sender_alloc();
if (snd == NULL) {
fprintf(stderr, "error: malloc() failed\n");
exit(1);
}
rtp_sender_init(snd, sock, name, ssrc);
status = rtp_sender_init_srtp(snd, &policy);
if (status) {
fprintf(stderr,
"error: srtp_create() failed with code %d\n",
status);
exit(1);
}
/* open dictionary */
dict = fopen (dictfile, "r");
if (dict == NULL) {
fprintf(stderr, "%s: couldn't open file %s\n", argv[0], dictfile);
if (ADDR_IS_MULTICAST(rcvr_addr.s_addr)) {
leave_group(sock, mreq, argv[0]);
}
exit(1);
}
/* read words from dictionary, then send them off */
while (fgets(word, MAX_WORD_LEN, dict) != NULL) {
len = strlen(word) + 1; /* plus one for null */
if (len > MAX_WORD_LEN)
printf("error: word %s too large to send\n", word);
else {
rtp_sendto(snd, word, len);
printf("sending word: %s", word);
}
usleep(USEC_RATE);
}
} else { /* prog_type == receiver */
rtp_receiver_t rcvr;
if (bind(sock, (struct sockaddr *)&name, sizeof(name)) < 0) {
close(sock);
fprintf(stderr, "%s: socket bind error\n", argv[0]);
perror(NULL);
if (ADDR_IS_MULTICAST(rcvr_addr.s_addr)) {
leave_group(sock, mreq, argv[0]);
}
exit(1);
}
rcvr = rtp_receiver_alloc();
if (rcvr == NULL) {
fprintf(stderr, "error: malloc() failed\n");
exit(1);
}
rtp_receiver_init(rcvr, sock, name, ssrc);
status = rtp_receiver_init_srtp(rcvr, &policy);
if (status) {
fprintf(stderr,
"error: srtp_create() failed with code %d\n",
status);
exit(1);
}
/* get next word and loop */
while (1) {
len = MAX_WORD_LEN;
if (rtp_recvfrom(rcvr, word, &len) > -1)
printf("\tword: %s", word);
}
}
if (ADDR_IS_MULTICAST(rcvr_addr.s_addr)) {
leave_group(sock, mreq, argv[0]);
}
#ifdef RTPW_USE_WINSOCK2
WSACleanup();
#endif
return 0;
}
void
usage(char *string) {
printf("usage: %s [-d <debug>]* [-k <key> [-a][-e]] "
"[-s | -r] dest_ip dest_port\n"
"or %s -l\n"
"where -a use message authentication\n"
" -e use encryption\n"
" -k <key> sets the srtp master key\n"
" -s act as rtp sender\n"
" -r act as rtp receiver\n"
" -l list debug modules\n"
" -d <debug> turn on debugging for module <debug>\n",
string, string);
exit(1);
}
void
leave_group(int sock, struct ip_mreq mreq, char *name) {
int ret;
ret = setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, (void*)&mreq,
sizeof(mreq));
if (ret < 0) {
fprintf(stderr, "%s: Failed to leave multicast group", name);
perror("");
}
}