TT#49600 separate RTCP en/decryption into perl module

Change-Id: Ibf1830c8fe2c9e01ae1bf93f4b62d7b62f1f88fb

perl/NGCP/Rtpclient/SRTP.pm

@@ -231,11 +231,11 @@ sub aes_cm_iv_rtp {
 }
 
 sub aes_cm_iv_rtcp {
-	my ($ctx, $r) = @_;
+	my ($r, $ssalt, $idx) = @_;
 
-	my $idx = $$ctx{rtcp_index} || 0;
+	$idx ||= 0;
 	my ($hdr, $ssrc) = unpack('a4a4', $r);
-	my $iv = xor_128($$ctx{rtcp_session_salt} . "\0\0",
+	my $iv = xor_128($ssalt . "\0\0",
 		$ssrc . "\0\0\0\0\0\0\0\0", pack("Nn", $idx, 0));
 	return $iv;
 }
@@ -249,10 +249,10 @@ sub aes_f8_iv_rtp {
 }
 
 sub aes_f8_iv_rtcp {
-	my ($ctx, $r) = @_;
+	my ($r, $ssalt, $idx) = @_;
 
 	my ($fields) = unpack('a8', $r);
-	my $iv = pack('a*Na*', "\0\0\0\0", (($$ctx{rtcp_index} || 0) | 0x80000000), $fields);
+	my $iv = pack('a*Na*', "\0\0\0\0", (($idx || 0) | 0x80000000), $fields);
 	return $iv;
 }
 
@@ -313,6 +313,52 @@ sub decrypt_rtp {
 	return ($pkt, $roc, $auth_tag, $hmac);
 }
 
+sub encrypt_rtcp {
+	my ($suite, $skey, $ssalt, $sauth, $idx, $mki, $mki_len, $unenc_srtcp, $packet) = @_;
+
+	my $iv = $suite->{iv_rtcp}->($packet, $ssalt, $idx);
+	my ($hdr, $to_enc) = unpack('a8a*', $packet);
+	my $enc = $unenc_srtcp ? $to_enc :
+		$suite->{enc_func}->($to_enc, $skey,
+		$iv, $ssalt);
+	my $pkt = $hdr . $enc;
+	$pkt .= pack("N", (($idx || 0) | ($unenc_srtcp ? 0 : 0x80000000)));
+
+	my $hmac = hmac_sha1($pkt, $sauth);
+
+	append_mki(\$pkt, $mki_len, $mki);
+
+	#$pkt .= pack("N", 1); # mki
+	$pkt .= substr($hmac, 0, 10);
+
+	$idx++;
+
+	return ($pkt, $idx);
+}
+
+sub decrypt_rtcp {
+	my ($suite, $skey, $ssalt, $sauth, $packet) = @_;
+
+	# XXX MKI, session parameters
+
+	my $plen = length($packet);
+	my $auth_tag = substr($packet, $plen - 10, 10);
+	my $idx_raw = substr($packet, $plen - 4 - 10, 4);
+	my ($idx) = unpack('N', $idx_raw);
+	$idx &= 0x7fffffff;
+	$packet = substr($packet, 0, $plen - 10 - 4);
+
+	my $iv = $suite->{iv_rtcp}->($packet, $ssalt, $idx);
+	my ($hdr, $to_enc) = unpack('a8a*', $packet);
+	my $enc = $suite->{enc_func}->($to_enc, $skey,
+		$iv, $ssalt);
+	my $pkt = $hdr . $enc;
+
+	my $hmac = hmac_sha1($packet, $sauth);
+
+	return ($pkt, $idx, $auth_tag, $hmac);
+}
+
 sub append_mki {
 	my ($pack_r, $mki_len, $mki) = @_;
 

tests/simulator-ng.pl

@@ -130,22 +130,9 @@ sub rtcp_encrypt {
 
 	($NOENC && $NOENC{rtcp_packet}) and return $NOENC{rtcp_packet};
 
-	my $iv = $$dctx{crypto_suite}{iv_rtcp}->($dctx, $r);
-	my ($hdr, $to_enc) = unpack('a8a*', $r);
-	my $enc = $$dctx{unenc_srtcp} ? $to_enc :
-		$$dctx{crypto_suite}{enc_func}->($to_enc, $$dctx{rtcp_session_key},
-		$iv, $$dctx{rtcp_session_salt});
-	my $pkt = $hdr . $enc;
-	$pkt .= pack("N", (($$dctx{rtcp_index} || 0) | ($$dctx{unenc_srtcp} ? 0 : 0x80000000)));
-
-	my $hmac = hmac_sha1($pkt, $$dctx{rtcp_session_auth_key});
-
-	NGCP::Rtpclient::SRTP::append_mki(\$pkt, @$dctx{qw(rtp_mki_len rtp_mki)});
-
-	#$pkt .= pack("N", 1); # mki
-	$pkt .= substr($hmac, 0, 10);
-
-	$$dctx{rtcp_index}++;
+	my ($pkt, $idx) = NGCP::Rtpclient::SRTP::encrypt_rtcp(@$dctx{qw(crypto_suite rtcp_session_key
+		rtcp_session_salt rtcp_session_auth_key rtcp_index rtp_mki rtp_mki_len unenc_srtcp)}, $r);
+	$$dctx{rtcp_index} = $idx;
 
 	$NOENC{rtcp_packet} = $pkt;