예제 #1
0
int
main (int argc, char *argv[]) {
  char errbuf[PCAP_ERRBUF_SIZE];
  bpf_u_int32 pcap_net = 0;
  pcap_t *pcap_handle;
#if BEW
  struct sockaddr_in local;
#endif 
  srtp_sec_serv_t sec_servs = sec_serv_none;
  int c;
  int key_size = 128;
  int tag_size = 8;
  int gcm_on = 0;
  char *input_key = NULL;
  int b64_input = 0;
  char key[MAX_KEY_LEN];
  struct bpf_program fp;
  char filter_exp[MAX_FILTER] = "";
  rtp_decoder_t dec;
  srtp_policy_t policy;
  srtp_err_status_t status;
  int len;
  int expected_len;
  int do_list_mods = 0;

  fprintf(stderr, "Using %s [0x%x]\n", srtp_get_version_string(), srtp_get_version());

  /* initialize srtp library */
  status = srtp_init();
  if (status) {
    fprintf(stderr, "error: srtp initialization failed with error code %d\n", status);
    exit(1);
  }

  /* check args */
  while (1) {
    c = getopt_s(argc, argv, "b:k:gt:ae:ld:f:");
    if (c == -1) {
      break;
    }
    switch (c) {
	case 'b':
      b64_input = 1;
      /* fall thru */
    case 'k':
      input_key = optarg_s;
      break;
    case 'e':
      key_size = atoi(optarg_s);
      if (key_size != 128 && key_size != 256) {
        fprintf(stderr, "error: encryption key size must be 128 or 256 (%d)\n", key_size);
        exit(1);
      }
      input_key = malloc(key_size);
      sec_servs |= sec_serv_conf;
      break;
    case 't':
      tag_size = atoi(optarg_s);
      if (tag_size != 8 && tag_size != 16) {
        fprintf(stderr, "error: GCM tag size must be 8 or 16 (%d)\n", tag_size);
        //exit(1);
      }
      break;
    case 'a':
      sec_servs |= sec_serv_auth;
      break;
    case 'g':
      gcm_on = 1;
      sec_servs |= sec_serv_auth;
      break;
    case 'd':
      status = srtp_crypto_kernel_set_debug_module(optarg_s, 1);
      if (status) {
        fprintf(stderr, "error: set debug module (%s) failed\n", optarg_s);
        exit(1);
      }
      break;
    case 'f':
      if(strlen(optarg_s) > MAX_FILTER){
        fprintf(stderr, "error: filter bigger than %d characters\n", MAX_FILTER);
        exit(1);
      }
      fprintf(stderr, "Setting filter as %s\n", optarg_s);
      strcpy(filter_exp, optarg_s);
      break;
    case 'l':
      do_list_mods = 1;
      break;
    default:
      usage(argv[0]);
    }
  }

  if (do_list_mods) {
    status = srtp_crypto_kernel_list_debug_modules();
    if (status) {
      fprintf(stderr, "error: list of debug modules failed\n");
	  exit(1);
    }
    return 0;
  }
   
  if ((sec_servs && !input_key) || (!sec_servs && input_key)) {
    /* 
     * a key must be provided if and only if security services have
     * been requested 
     */
	  if(input_key == NULL){
		  fprintf(stderr, "key not provided\n");
	  }
	  if(!sec_servs){
		  fprintf(stderr, "no secservs\n");
	  }
    fprintf(stderr, "provided\n");
    usage(argv[0]);
  }
   


  /* report security services selected on the command line */
  fprintf(stderr, "security services: ");
  if (sec_servs & sec_serv_conf)
    fprintf(stderr, "confidentiality ");
  if (sec_servs & sec_serv_auth)
    fprintf(stderr, "message authentication");
  if (sec_servs == sec_serv_none)
    fprintf(stderr, "none");
  fprintf(stderr, "\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:
      if (gcm_on) {
#ifdef OPENSSL
	switch (key_size) {
	case 128:
	  srtp_crypto_policy_set_aes_gcm_128_8_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_128_8_auth(&policy.rtcp);
	  break;
	case 256:
	  srtp_crypto_policy_set_aes_gcm_256_8_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_256_8_auth(&policy.rtcp);
	  break;
	}
#else
	fprintf(stderr, "error: GCM mode only supported when using the OpenSSL crypto engine.\n");
	return 0;
#endif
      } else {
	switch (key_size) {
	case 128:
          srtp_crypto_policy_set_rtp_default(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);
	  break;
	case 256:
          srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);
	  break;
	}
      }
      break;
    case sec_serv_conf:
      if (gcm_on) {
	  fprintf(stderr, "error: GCM mode must always be used with auth enabled\n");
	  return -1;
      } else {
	switch (key_size) {
	case 128:
          srtp_crypto_policy_set_aes_cm_128_null_auth(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);      
	  break;
	case 256:
          srtp_crypto_policy_set_aes_cm_256_null_auth(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);      
	  break;
	}
      }
      break;
    case sec_serv_auth:
      if (gcm_on) {
#ifdef OPENSSL
	switch (key_size) {
	case 128:
	  srtp_crypto_policy_set_aes_gcm_128_8_only_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_128_8_only_auth(&policy.rtcp);
	  break;
	case 256:
	  srtp_crypto_policy_set_aes_gcm_256_8_only_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_256_8_only_auth(&policy.rtcp);
	  break;
	}
#else
	printf("error: GCM mode only supported when using the OpenSSL crypto engine.\n");
	return 0;
#endif
      } else {
        srtp_crypto_policy_set_null_cipher_hmac_sha1_80(&policy.rtp);
        srtp_crypto_policy_set_rtcp_default(&policy.rtcp);
      }
      break;
    default:
      fprintf(stderr, "error: unknown security service requested\n");
      return -1;
    } 

    policy.key  = (uint8_t *) key;
    policy.ekt  = NULL;
    policy.next = NULL;
    policy.window_size = 128;
    policy.allow_repeat_tx = 0;
    policy.rtp.sec_serv = sec_servs;
    policy.rtcp.sec_serv = sec_servs; //sec_serv_none;  /* we don't do RTCP anyway */
      fprintf(stderr, "setting tag len %d\n", tag_size);
policy.rtp.auth_tag_len = tag_size;
  
    if (gcm_on && tag_size != 8) {
      fprintf(stderr, "setted tag len %d\n", tag_size);
	policy.rtp.auth_tag_len = tag_size;
    }

    /*
     * read key from hexadecimal or base64 on command line into an octet string
     */
    if (b64_input) {
      int pad;
      expected_len = policy.rtp.cipher_key_len*4/3;
      len = base64_string_to_octet_string(key, &pad, input_key, expected_len);
      if (pad != 0) {
        fprintf(stderr, "error: padding in base64 unexpected\n");
        exit(1);
      }
    } else {
      expected_len = policy.rtp.cipher_key_len*2;
      len = hex_string_to_octet_string(key, input_key, expected_len);
    }
    /* check that hex string is the right length */
    if (len < expected_len) {
      fprintf(stderr, 
	      "error: too few digits in key/salt "
	      "(should be %d digits, found %d)\n",
	      expected_len, len);
      exit(1);    
    } 
    if (strlen(input_key) > policy.rtp.cipher_key_len*2) {
      fprintf(stderr, 
	      "error: too many digits in key/salt "
	      "(should be %d hexadecimal digits, found %u)\n",
	      policy.rtp.cipher_key_len*2, (unsigned)strlen(input_key));
      exit(1);    
    }
    
    fprintf(stderr, "set master key/salt to %s/", octet_string_hex_string(key, 16));
    fprintf(stderr, "%s\n", octet_string_hex_string(key+16, 14));
  
  } else {
      fprintf(stderr, "error: neither encryption or authentication were selected");
      exit(1);    
  }

	pcap_handle = pcap_open_offline("-", errbuf);

	if (!pcap_handle) {
	    fprintf(stderr, "libpcap failed to open file '%s'\n", errbuf);
	    exit(1);
	}
	assert(pcap_handle != NULL);
	if ((pcap_compile(pcap_handle, &fp, filter_exp, 1, pcap_net)) == -1){
	    fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp,
	        pcap_geterr(pcap_handle));
	    return (2);
	}
	if (pcap_setfilter(pcap_handle, &fp) == -1){
	  fprintf(stderr, "couldn't install filter %s: %s\n", filter_exp,
	      pcap_geterr(pcap_handle));
	  return (2);
	}
	dec = rtp_decoder_alloc();
	if (dec == NULL) {
	  fprintf(stderr, "error: malloc() failed\n");
	  exit(1);
	}
	fprintf(stderr, "Starting decoder\n");
	rtp_decoder_init(dec, policy);

	pcap_loop(pcap_handle, 0, rtp_decoder_handle_pkt, (u_char *)dec);

	rtp_decoder_deinit_srtp(dec);
	rtp_decoder_dealloc(dec);

  status = srtp_shutdown();
  if (status) {
    fprintf(stderr, "error: srtp shutdown failed with error code %d\n", status);
    exit(1);
  }

  return 0;
}
예제 #2
0
파일: rtpw.c 프로젝트: Harut42/libsrtp
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;
  srtp_sec_serv_t sec_servs = sec_serv_none;
  unsigned char ttl = 5;
  int c;
  int key_size = 128;
  int tag_size = 8;
  int gcm_on = 0;
  char *input_key = NULL;
  int b64_input = 0;
  char *address = NULL;
  char key[MAX_KEY_LEN];
  unsigned short port = 0;
  rtp_sender_t snd;
  srtp_policy_t policy;
  srtp_err_status_t status;
  int len;
  int expected_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

  printf("Using %s [0x%x]\n", srtp_get_version_string(), srtp_get_version());

  if (setup_signal_handler(argv[0]) != 0) {
    exit(1);
  }

  /* 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, "b:k:rsgt:ae:ld:");
    if (c == -1) {
      break;
    }
    switch (c) {
	case 'b':
      b64_input = 1;
      /* fall thru */
    case 'k':
      input_key = optarg_s;
      break;
    case 'e':
      key_size = atoi(optarg_s);
      if (key_size != 128 && key_size != 256) {
        printf("error: encryption key size must be 128 or 256 (%d)\n", key_size);
        exit(1);
      }
      sec_servs |= sec_serv_conf;
      break;
    case 't':
      tag_size = atoi(optarg_s);
      if (tag_size != 8 && tag_size != 16) {
        printf("error: GCM tag size must be 8 or 16 (%d)\n", tag_size);
        exit(1);
      }
      break;
    case 'a':
      sec_servs |= sec_serv_auth;
      break;
    case 'g':
      gcm_on = 1;
      sec_servs |= sec_serv_auth;
      break;
    case 'r':
      prog_type = receiver;
      break;
    case 's':
      prog_type = sender;
      break;
    case 'd':
      status = srtp_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 = srtp_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:
      if (gcm_on) {
#ifdef OPENSSL
	switch (key_size) {
	case 128:
	  srtp_crypto_policy_set_aes_gcm_128_8_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_128_8_auth(&policy.rtcp);
	  break;
	case 256:
	  srtp_crypto_policy_set_aes_gcm_256_8_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_256_8_auth(&policy.rtcp);
	  break;
	}
#else
	printf("error: GCM mode only supported when using the OpenSSL crypto engine.\n");
	return 0;
#endif
      } else {
	switch (key_size) {
	case 128:
          srtp_crypto_policy_set_rtp_default(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);
	  break;
	case 256:
          srtp_crypto_policy_set_aes_cm_256_hmac_sha1_80(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);
	  break;
	}
      }
      break;
    case sec_serv_conf:
      if (gcm_on) {
	  printf("error: GCM mode must always be used with auth enabled\n");
	  return -1;
      } else {
	switch (key_size) {
	case 128:
          srtp_crypto_policy_set_aes_cm_128_null_auth(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);      
	  break;
	case 256:
          srtp_crypto_policy_set_aes_cm_256_null_auth(&policy.rtp);
          srtp_crypto_policy_set_rtcp_default(&policy.rtcp);      
	  break;
	}
      }
      break;
    case sec_serv_auth:
      if (gcm_on) {
#ifdef OPENSSL
	switch (key_size) {
	case 128:
	  srtp_crypto_policy_set_aes_gcm_128_8_only_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_128_8_only_auth(&policy.rtcp);
	  break;
	case 256:
	  srtp_crypto_policy_set_aes_gcm_256_8_only_auth(&policy.rtp);
	  srtp_crypto_policy_set_aes_gcm_256_8_only_auth(&policy.rtcp);
	  break;
	}
#else
	printf("error: GCM mode only supported when using the OpenSSL crypto engine.\n");
	return 0;
#endif
      } else {
        srtp_crypto_policy_set_null_cipher_hmac_sha1_80(&policy.rtp);
        srtp_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.ekt  = NULL;
    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 */

    if (gcm_on && tag_size != 8) {
	policy.rtp.auth_tag_len = tag_size;
    }

    /*
     * read key from hexadecimal or base64 on command line into an octet string
     */
    if (b64_input) {
        int pad;
        expected_len = (policy.rtp.cipher_key_len*4)/3;
        len = base64_string_to_octet_string(key, &pad, input_key, expected_len);
        if (pad != 0) {
          fprintf(stderr, "error: padding in base64 unexpected\n");
          exit(1);
        }
    } else {
        expected_len = policy.rtp.cipher_key_len*2;
        len = hex_string_to_octet_string(key, input_key, expected_len);
    }
    /* check that hex string is the right length */
    if (len < expected_len) {
      fprintf(stderr, 
	      "error: too few digits in key/salt "
	      "(should be %d digits, found %d)\n",
	      expected_len, len);
      exit(1);    
    } 
    if ((int) strlen(input_key) > policy.rtp.cipher_key_len*2) {
      fprintf(stderr, 
	      "error: too many digits in key/salt "
	      "(should be %d hexadecimal digits, found %u)\n",
	      policy.rtp.cipher_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.
     */
    srtp_crypto_policy_set_null_cipher_hmac_null(&policy.rtp);
    srtp_crypto_policy_set_null_cipher_hmac_null(&policy.rtcp);
    policy.key                 = (uint8_t *)key;
    policy.ssrc.type           = ssrc_specific;
    policy.ssrc.value          = ssrc;
    policy.window_size         = 0;
    policy.allow_repeat_tx     = 0;
    policy.ekt                 = NULL;
    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 (!interrupted && 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);
    }

    rtp_sender_deinit_srtp(snd);
    rtp_sender_dealloc(snd);

    fclose(dict);
  } 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 (!interrupted) {
      len = MAX_WORD_LEN;
      if (rtp_recvfrom(rcvr, word, &len) > -1)
	printf("\tword: %s\n", word);
    }
      
    rtp_receiver_deinit_srtp(rcvr);
    rtp_receiver_dealloc(rcvr);
  } 

  if (ADDR_IS_MULTICAST(rcvr_addr.s_addr)) {
    leave_group(sock, mreq, argv[0]);
  }

#ifdef RTPW_USE_WINSOCK2
  ret = closesocket(sock);
#else
  ret = close(sock);
#endif
  if (ret < 0) {
    fprintf(stderr, "%s: Failed to close socket", argv[0]);
    perror("");
  }

  status = srtp_shutdown();
  if (status) {
    printf("error: srtp shutdown failed with error code %d\n", status);
    exit(1);
  }

#ifdef RTPW_USE_WINSOCK2
  WSACleanup();
#endif

  return 0;
}