adding srtp support to simulator script

pull/2/merge
Richard Fuchs 12 years ago
parent 94393efada
commit ec1946fde8

@ -9,6 +9,9 @@ use Getopt::Long;
use Socket6;
use Bencode qw( bencode bdecode );
use Time::HiRes;
use Crypt::Rijndael;
use Digest::SHA qw(hmac_sha1);
use MIME::Base64;
my ($NUM, $RUNTIME, $STREAMS) = (1000, 30, 1);
my ($NODEL, $IP, $IPV6, $KEEPGOING, $REINVITES, $BRANCHES);
@ -29,6 +32,14 @@ GetOptions(
$SIG{ALRM} = sub { print "alarm!\n"; };
setrlimit(RLIMIT_NOFILE, 8000, 8000);
# global for now
#my $srtp_master_key = pack("H*", 'E1F97A0D3E018BE0D64FA32C06DE4139');
#my $srtp_master_salt = pack("H*", '0EC675AD498AFEEBB6960B3AABE6');
#my ($srtp_session_key, $srtp_session_auth_key, $srtp_session_salt)
# = gen_rtp_session_keys($srtp_master_key, $srtp_master_salt);
#my ($srtcp_session_key, $srtcp_session_auth_key, $srtcp_session_salt)
# = gen_rtcp_session_keys($srtp_master_key, $srtp_master_salt);
my @chrs = ('a' .. 'z', 'A' .. 'Z', '0' .. '9');
sub rand_str {
my ($len) = @_;
@ -76,21 +87,160 @@ sub send_receive {
return $x;
}
sub send_expect {
my ($send_fd, $receive_fd, $payload, $expect, $destination) = @_;
sub aes_cm {
my ($data, $key, $iv) = @_;
my $c = Crypt::Rijndael->new($key) or die;
length($iv) == 16 or die;
my @iv = unpack("C16", $iv);
my $out = '';
while ($data ne '') {
$iv = pack("C16", @iv);
my $key_segment = $c->encrypt($iv);
length($key_segment) == 16 or die;
my @ks = unpack("C16", $key_segment);
my @ds = unpack("C16", $data);
for my $i (0 .. $#ds) {
my $ss = $ds[$i];
my $kk = $ks[$i];
$out .= chr($ss ^ $kk);
}
substr($data, 0, 16, '');
$data eq '' and last;
my $x = send_receive($send_fd, $receive_fd, $payload, $destination);
if (($x || '') ne $expect) {
return 0;
for my $i (reverse(0 .. 15)) {
$iv[$i]++;
if ($iv[$i] == 256) {
$iv[$i] = 0;
}
else {
last;
}
}
}
return 1;
return $out;
}
sub prf_n {
my ($n, $key, $x) = @_;
my $d = "\0" x ($n / 8);
my $ks = aes_cm($d, $key, $x . "\0\0");
return substr($ks, 0, $n / 8);
}
sub xor_n {
my ($n, @l) = @_;
$n /= 8;
my @o = (0) x $n;
for my $e (@l) {
my @e = unpack("C$n", $e);
if (@e < $n) {
unshift(@e, ((0) x ($n - @e)));
}
for my $i (0 .. $#o) {
$o[$i] ^= $e[$i];
}
}
return pack("C$n", @o);
}
sub xor_112 {
return xor_n(112, @_);
}
sub xor_128 {
return xor_n(128, @_);
}
sub gen_rtp_session_keys {
my ($master_key, $master_salt) = @_;
my $session_key = prf_n(128, $master_key, xor_112($master_salt, "\0\0\0\0\0\0\0"));
my $auth_key = prf_n(160, $master_key, xor_112($master_salt, "\1\0\0\0\0\0\0"));
my $session_salt = prf_n(112, $master_key, xor_112($master_salt, "\2\0\0\0\0\0\0"));
return ($session_key, $auth_key, $session_salt);
}
sub gen_rtcp_session_keys {
my ($master_key, $master_salt) = @_;
my $session_key = prf_n(128, $master_key, xor_112($master_salt, "\3\0\0\0\0"));
my $auth_key = prf_n(160, $master_key, xor_112($master_salt, "\4\0\0\0\0"));
my $session_salt = prf_n(112, $master_key, xor_112($master_salt, "\5\0\0\0\0"));
return ($session_key, $auth_key, $session_salt);
}
sub rtcp_encrypt {
my ($r, $ctx, $dir) = @_;
if (!$$ctx{rtcp_session_key}) {
($$ctx{$dir}{rtcp_session_key}, $$ctx{$dir}{rtcp_session_auth_key}, $$ctx{$dir}{rtcp_session_salt})
= gen_rtp_session_keys($$ctx{$dir}{rtp_master_key}, $$ctx{$dir}{rtp_master_salt});
}
my $idx = $$ctx{$dir}{rtcp_index} || 0;
my ($hdr, $ssrc, $to_enc) = unpack('a4a4a*', $r);
my $iv = xor_128($$ctx{$dir}{rtcp_session_salt} . "\0\0",
$ssrc . "\0\0\0\0\0\0\0\0", pack("Nn", $idx, 0));
my $enc = aes_cm($to_enc, $$ctx{$dir}{rtcp_session_key}, $iv);
my $pkt = $hdr . $ssrc . $enc;
$pkt .= pack("N", ($idx | 0x80000000));
my $hmac = hmac_sha1($pkt, $$ctx{$dir}{rtcp_session_auth_key});
#$pkt .= pack("N", 1); # mki
$pkt .= substr($hmac, 0, 10);
$$ctx{$dir}{rtcp_index} = ++$idx;
return $pkt;
}
sub rtp_encrypt {
my ($r, $ctx, $dir) = @_;
if (!$$ctx{$dir}{rtp_session_key}) {
($$ctx{$dir}{rtp_session_key}, $$ctx{$dir}{rtp_session_auth_key}, $$ctx{$dir}{rtp_session_salt})
= gen_rtp_session_keys($$ctx{$dir}{rtp_master_key}, $$ctx{$dir}{rtp_master_salt});
}
my $roc = $$ctx{$dir}{rtp_roc} || 0;
my ($hdr, $seq, $ts, $ssrc, $to_enc) = unpack('a2na4a4a*', $r);
$seq == 0 and $roc++;
my $iv = xor_128($$ctx{$dir}{rtp_session_salt} . "\0\0",
$ssrc . "\0\0\0\0\0\0\0\0", pack("Nnn", $roc, $seq, 0));
my $enc = aes_cm($to_enc, $$ctx{$dir}{rtp_session_key}, $iv);
my $pkt = pack("a*na*a*a*", $hdr, $seq, $ts, $ssrc, $enc);
my $hmac = hmac_sha1($pkt . pack("N", $roc), $$ctx{$dir}{rtp_session_auth_key});
#$pkt .= pack("N", 1); # mki
$pkt .= substr($hmac, 0, 10);
$$ctx{$dir}{rtp_roc} = $roc;
return $pkt;
}
sub savp_sdp {
my ($ctx) = @_;
if (!$$ctx{out}{rtp_master_key}) {
$$ctx{out}{rtp_master_key} = rand_str(16);
$$ctx{out}{rtp_master_salt} = rand_str(14);
}
return "a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:" . encode_base64($$ctx{out}{rtp_master_key} . $$ctx{out}{rtp_master_salt}, '') . "\n";
}
sub rtcp_sr {
my @now = Time::HiRes::gettimeofday();
my $secs = $now[0] + 2208988800;
my $frac = $now[1] / 1000000 * 2**32;
my $sr = pack('CCnN NNN NN', (2 << 6) | 1, 200, 12, rand() * 2**32, $secs, $frac,
my $sr = pack('CCnN NNN NN', (2 << 6) | 1, 200, 12, rand(2**32), $secs, $frac,
12345, 0, 0);
$sr .= pack('N CCCC NNNN', 0, 0, 0, 0, 0, 0, 0, 0, 0);
return $sr;
@ -101,13 +251,24 @@ sub rtcp_rtpfb {
}
sub rtcp_avp {
my ($recv, $send) = @_;
my ($recv, $ctx, $ctx_o) = @_;
my $sr = rtcp_sr();
my $exp = $sr;
$$recv{name} eq 'RTP/SAVP' and $exp = rtcp_encrypt($sr, $ctx_o, 'in');
return ($sr, $exp);
}
sub rtcp_savp {
my ($recv, $ctx, $ctx_o) = @_;
my $sr = rtcp_sr();
return ($sr, $sr);
my $enc = rtcp_encrypt($sr, $ctx, 'out');
my $exp = $enc;
$$recv{name} eq 'RTP/AVP' and $exp = $sr;
return ($enc, $exp);
}
sub rtcp_avpf {
my ($recv, $send) = @_;
my ($recv, $ctx, $ctx_o) = @_;
my $sr = rtcp_sr();
my $fb = rtcp_rtpfb();
my $exp = $sr;
@ -115,28 +276,78 @@ sub rtcp_avpf {
return ($sr . $fb, $exp);
}
sub rtp {
my ($ctx) = @_;
my $seq = $$ctx{rtp_seqnum} || (int(rand(0xfffff)) + 1);
my $hdr = pack("CCnNN", 0x80, 0x00, $seq, rand(2**32), rand(2**32));
my $pack = $hdr . rand_str(100);
$$ctx{rtp_seqnum} = (++$seq & 0xffff);
return $pack;
}
sub rtp_avp {
my ($recv, $ctx, $ctx_o) = @_;
my $pack = rtp($ctx);
my $exp = $pack;
$$recv{name} eq 'RTP/SAVP' and $exp = rtp_encrypt($pack, $ctx_o, 'in');
return ($pack, $exp);
}
sub rtp_savp {
my ($recv, $ctx, $ctx_o) = @_;
my $pack = rtp($ctx);
my $enc = rtp_encrypt($pack, $ctx, 'out');
my $exp = $enc;
$$recv{name} eq 'RTP/AVP' and $exp = $pack;
return ($enc, $exp);
}
sub savp_crypto {
my ($sdp, $ctx) = @_;
my @a = $sdp =~ /[\r\n]a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:([\w\/+]{40})(?:\|(?:2\^(\d+)|(\d+)))?(?:\|(\d+):(\d+))?[\r\n]/si;
@a or die;
my $ks = decode_base64($a[0]);
length($ks) == 30 or die;
($$ctx{in}{rtp_master_key}, $$ctx{in}{rtp_master_salt}) = unpack('a16a14', $ks);
$$ctx{in}{rtp_mki} = $a[3];
$$ctx{in}{rtp_mki_len} = $a[4];
}
sub hexdump {
my $o = '';
for my $a (@_) {
$o .= "<< " . unpack("H*", $a) . " >> ";
}
return $o;
}
sub do_rtp {
print("sending rtp\n");
for my $c (@calls) {
$c or next;
my ($fds,$outputs,$protos,$cfds,$trans) = @$c{qw(fds outputs protos rtcp_fds transports)};
my ($fds,$outputs,$protos,$cfds,$trans,$tctxs)
= @$c{qw(fds outputs protos rtcp_fds transports trans_contexts)};
for my $j (0 .. $#{$$fds[0]}) {
for my $i ([0,1],[1,0]) {
my ($a, $b) = @$i;
my $pr = $$protos[$a];
my $tcx = $$tctxs[$a];
my $tcx_o = $$tctxs[$b];
my $addr = inet_pton($$pr{family}, $$outputs[$b][$j][1]);
my $payload = rand_str(100);
my ($payload, $expect) = $$trans[$a]{rtp_func}($$trans[$b], $tcx, $tcx_o);
my $dst = $$pr{sockaddr}($$outputs[$b][$j][0], $addr);
if (!send_expect($$fds[$a][$j], $$fds[$b][$j], $payload, $payload, $dst)) {
my $repl = send_receive($$fds[$a][$j], $$fds[$b][$j], $payload, $dst);
if ($repl eq '') {
warn("no rtp reply received, ports $$outputs[$b][$j][0] and $$outputs[$a][$j][0]");
$KEEPGOING or undef($c);
}
$repl eq $expect or die hexdump($repl, $expect);
my $expect;
($payload, $expect) = $$trans[$a]{rtcp_func}($$trans[$b], $$trans[$a]);
($payload, $expect) = $$trans[$a]{rtcp_func}($$trans[$b], $tcx, $tcx_o);
$dst = $$pr{sockaddr}($$outputs[$b][$j][0] + 1, $addr);
my $repl = send_receive($$cfds[$a][$j], $$cfds[$b][$j], $payload, $dst);
$repl eq $expect or die;
$repl = send_receive($$cfds[$a][$j], $$cfds[$b][$j], $payload, $dst);
$repl eq $expect or die hexdump($repl, $expect);
}
}
}
@ -170,11 +381,20 @@ my @sides = qw(A B);
my @transports = (
{
name => 'RTP/AVP',
rtp_func => \&rtp_avp,
rtcp_func => \&rtcp_avp,
},
# {
# name => 'RTP/AVPF',
# rtp_func => &rtp_avpf,
# rtcp_func => \&rtcp_avpf,
# },
{
name => 'RTP/AVPF',
rtcp_func => \&rtcp_avpf,
name => 'RTP/SAVP',
sdp_media_params => \&savp_sdp,
sdp_parse_func => \&savp_crypto,
rtp_func => \&rtp_savp,
rtcp_func => \&rtcp_savp,
},
);
@ -200,6 +420,7 @@ sub update_lookup {
my $protos = $$c{protos} || ($$c{protos} = []);
my $trans = $$c{transports} || ($$c{transports} = []);
my $tctxs = $$c{trans_contexts} || ($$c{trans_contexts} = []);
my $fds_a = $$c{fds} || ($$c{fds} = []);
my $cfds_a = $$c{rtcp_fds} || ($$c{rtcp_fds} = []);
for my $x (0,1) {
@ -214,6 +435,8 @@ sub update_lookup {
}
my ($pr, $pr_o) = @$protos[$i, $j];
my ($tr, $tr_o) = @$trans[$i, $j];
my $tcx = $$tctxs[$i] || ($$tctxs[$i] = {});
my $tcx_o = $$tctxs[$j] || ($$tctxs[$j] = {});
my @commands = qw(offer answer);
my $ports_a = $$c{ports} || ($$c{ports} = []);
@ -264,7 +487,9 @@ m=audio $p $$tr{name} 8
a=rtpmap:8 PCMA/8000
a=rtcp:$cp
!
$$tr{sdp_media_params} and $sdp .= $$tr{sdp_media_params}($tcx);
}
print("transport is $$tr{name} -> $$tr_o{name}\n"); # XXX
my $dict = {sdp => $sdp, command => $commands[$i], 'call-id' => $callid,
'from-tag' => $$tags[0],
@ -278,6 +503,7 @@ a=rtcp:$cp
$i == 1 and $dict->{'to-tag'} = $$tags[1];
my $o = msg($dict);
$$o{result} eq 'ok' or die;
my ($rp_af, $rp_add) = $$o{sdp} =~ /c=IN IP([46]) (\S+)/s or die;
my @rp_ports = $$o{sdp} =~ /m=audio (\d+) \Q$$tr_o{name}\E /gs or die;
@ -288,6 +514,7 @@ a=rtcp:$cp
$rpl == 0 and die "mediaproxy ran out of ports";
push(@$rpl_t, [$rpl,$rp_add]);
}
$$tr_o{sdp_parse_func} and $$tr_o{sdp_parse_func}($$o{sdp}, $tcx_o);
}
for my $iter (1 .. $NUM) {

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