diff --git a/src/org/jitsi/impl/neomedia/transform/csrc/SsrcTransformEngine.java b/src/org/jitsi/impl/neomedia/transform/csrc/SsrcTransformEngine.java
index 818499b1f1896440ecbb6030f3698157728d3545..8a8d455ce3ba8fe47d2adda6476d1c8d567d4903 100644
--- a/src/org/jitsi/impl/neomedia/transform/csrc/SsrcTransformEngine.java
+++ b/src/org/jitsi/impl/neomedia/transform/csrc/SsrcTransformEngine.java
@@ -14,6 +14,8 @@
import org.jitsi.impl.neomedia.*;
import org.jitsi.impl.neomedia.transform.*;
+import org.jitsi.service.configuration.*;
+import org.jitsi.service.libjitsi.*;
import org.jitsi.service.neomedia.*;
/**
@@ -41,11 +43,36 @@ public class SsrcTransformEngine
+ ".dropMutedAudioSourceInReverseTransform";
/**
- * The indicator which determines whether this <tt>SsrcTransformEngine</tt>
- * is to drop RTP packets indicated as generated from a muted audio source
- * in {@link #reverseTransform(RawPacket)}.
+ * The indicator which determines whether <tt>SsrcTransformEngine</tt> is to
+ * drop RTP packets indicated as generated from a muted audio source in
+ * {@link #reverseTransform(RawPacket)}.
+ */
+ private static boolean dropMutedAudioSourceInReverseTransform = false;
+
+ /**
+ * The maximum number of consecutive RTP packets indicated as generated from
+ * a muted audio source to be dropped in
+ * {@link #reverseTransform(RawPacket)}. Makes sure that SRTP at the
+ * receiving endpoint/peer sees enough sequence numbers to not get its SRTP
+ * index out of sync with the sending endpoint/peer.
+ */
+ private static final int MAX_DROPPED_MUTED_AUDIO_SOURCE_IN_REVERSE_TRANSFORM
+ = 1023;
+
+ /**
+ * The indicator which determines whether the method
+ * {@link #readConfigurationServicePropertiesOnce()} is to read the values
+ * of certain <tt>ConfigurationService</tt> properties of concern to
+ * <tt>SsrcTransformEngine</tt> once during the initialization of the first
+ * instance.
+ */
+ private static boolean readConfigurationServicePropertiesOnce = true;
+
+ /**
+ * The number of consecutive RTP packets indicated as generated from a muted
+ * audio source and dropped in {@link #reverseTransform(RawPacket)}.
*/
- private final boolean dropMutedAudioSourceInReverseTransform;
+ private int droppedMutedAudioSourceInReverseTransform;
/**
* The <tt>MediaDirection</tt> in which this RTP header extension is active.
@@ -92,15 +119,7 @@ public SsrcTransformEngine(MediaStreamImpl mediaStream)
}
}
- /*
- * Should we simply drop RTP packets from muted audio sources? It turns
- * out that we cannot do that because SRTP at the receiver will
- * eventually fail to guess the rollover counter (ROC) of the sender.
- * That is why we will never drop RTP packets from muted audio sources
- * here and we will rather raise Buffer.FLAG_SILENCE and have SRTP drop
- * RTP packets from muted audio sources.
- */
- dropMutedAudioSourceInReverseTransform = false;
+ readConfigurationServicePropertiesOnce();
}
/**
@@ -135,6 +154,30 @@ public PacketTransformer getRTPTransformer()
return this;
}
+ /**
+ * Reads the values of certain <tt>ConfigurationService</tt> properties of
+ * concern to <tt>SsrcTransformEngine</tt> once during the initialization of
+ * the first instance.
+ */
+ private static synchronized void readConfigurationServicePropertiesOnce()
+ {
+ if (readConfigurationServicePropertiesOnce)
+ readConfigurationServicePropertiesOnce = false;
+ else
+ return;
+
+ ConfigurationService cfg = LibJitsi.getConfigurationService();
+
+ if (cfg != null)
+ {
+ dropMutedAudioSourceInReverseTransform
+ = cfg.getBoolean(
+ SsrcTransformEngine
+ .DROP_MUTED_AUDIO_SOURCE_IN_REVERSE_TRANSFORM,
+ dropMutedAudioSourceInReverseTransform);
+ }
+ }
+
/**
* Extracts the list of CSRC identifiers and passes it to the
* <tt>MediaStream</tt> associated with this engine. Other than that the
@@ -150,6 +193,8 @@ public PacketTransformer getRTPTransformer()
*/
public RawPacket reverseTransform(RawPacket pkt)
{
+ boolean dropPkt = false;
+
if ((ssrcAudioLevelExtID > 0)
&& ssrcAudioLevelDirection.allowsReceiving()
&& !pkt.isInvalid()
@@ -160,13 +205,27 @@ public RawPacket reverseTransform(RawPacket pkt)
if (level == 127 /* a muted audio source */)
{
if (dropMutedAudioSourceInReverseTransform)
- pkt = null;
+ {
+ dropPkt
+ = droppedMutedAudioSourceInReverseTransform
+ < MAX_DROPPED_MUTED_AUDIO_SOURCE_IN_REVERSE_TRANSFORM;
+ }
else
+ {
pkt.setFlags(Buffer.FLAG_SILENCE | pkt.getFlags());
+ }
}
}
-
- return pkt;
+ if (dropPkt)
+ {
+ droppedMutedAudioSourceInReverseTransform++;
+ return null;
+ }
+ else
+ {
+ droppedMutedAudioSourceInReverseTransform = 0;
+ return pkt;
+ }
}
public void setSsrcAudioLevelExtensionID(byte extID, MediaDirection dir)
diff --git a/src/org/jitsi/impl/neomedia/transform/srtp/SRTPCryptoContext.java b/src/org/jitsi/impl/neomedia/transform/srtp/SRTPCryptoContext.java
index 300d40b804c11170e07299ef1df4d1559c2aa1d8..1daeed0fabf7d263fec6de08cd4145052eeb1e61 100644
--- a/src/org/jitsi/impl/neomedia/transform/srtp/SRTPCryptoContext.java
+++ b/src/org/jitsi/impl/neomedia/transform/srtp/SRTPCryptoContext.java
@@ -28,8 +28,6 @@
import java.util.*;
-import javax.media.*;
-
import org.bouncycastle.crypto.*;
import org.bouncycastle.crypto.digests.*;
import org.bouncycastle.crypto.engines.*;
@@ -38,7 +36,6 @@
import org.jitsi.bccontrib.macs.SkeinMac;
import org.jitsi.bccontrib.params.*;
import org.jitsi.impl.neomedia.*;
-import org.jitsi.impl.neomedia.transform.csrc.*;
import org.jitsi.service.configuration.*;
import org.jitsi.service.libjitsi.*;
import org.jitsi.util.*;
@@ -84,13 +81,6 @@ public class SRTPCryptoContext
*/
private static boolean checkReplay = true;
- /**
- * The indicator which determines whether <tt>SRTPCryptoContext</tt>
- * is to drop RTP packets indicated as generated from a muted audio source
- * in {@link #reverseTransformPacket(RawPacket)}.
- */
- private static boolean dropMutedAudioSourceInReverseTransform = false;
-
/**
* The <tt>Logger</tt> used by the <tt>SRTPCryptoContext</tt> class and its
* instances to print out debug information.
@@ -506,64 +496,42 @@ public boolean reverseTransformPacket(RawPacket pkt)
}
// Guess the SRTP index (48 bit), see RFC 3711, 3.3.1
- // Stores the guessed ROC in this.guessedROC
+ // Stores the guessed rollover counter (ROC) in this.guessedROC.
long guessedIndex = guessIndex(seqNo);
+ boolean b = false;
- /* Replay control */
- if (!checkReplay(seqNo, guessedIndex))
- return false;
-
- /* Authenticate the packet. */
- if (checkReplay && !authenticatePacket(pkt))
- return false;
-
- /*
- * If the specified pkt represents an RTP packet generated by a muted
- * audio source, (maybe) do not waste processing power on decrypting it.
- */
- boolean dropPkt;
-
- if (!dropMutedAudioSourceInReverseTransform
- || ((Buffer.FLAG_SILENCE & pkt.getFlags()) == 0))
+ // Replay control
+ if (checkReplay(seqNo, guessedIndex))
{
- /*
- * XXX If we are to drop (S)RTP packets indicated as generated from
- * a muted audio source and the protection against relay attacks is
- * deactivated, we will NOT authenticate such a packet in order to
- * maximize the sparing of the CPU.
- */
- if (!checkReplay && !authenticatePacket(pkt))
- return false;
-
- switch (policy.getEncType())
+ // Authenticate the packet.
+ if (authenticatePacket(pkt))
{
- // Decrypt the packet using Counter Mode encryption.
- case SRTPPolicy.AESCM_ENCRYPTION:
- case SRTPPolicy.TWOFISH_ENCRYPTION:
- processPacketAESCM(pkt);
- break;
-
- // Decrypt the packet using F8 Mode encryption.
- case SRTPPolicy.AESF8_ENCRYPTION:
- case SRTPPolicy.TWOFISHF8_ENCRYPTION:
- processPacketAESF8(pkt);
- break;
+ switch (policy.getEncType())
+ {
+ // Decrypt the packet using Counter Mode encryption.
+ case SRTPPolicy.AESCM_ENCRYPTION:
+ case SRTPPolicy.TWOFISH_ENCRYPTION:
+ processPacketAESCM(pkt);
+ break;
+
+ // Decrypt the packet using F8 Mode encryption.
+ case SRTPPolicy.AESF8_ENCRYPTION:
+ case SRTPPolicy.TWOFISHF8_ENCRYPTION:
+ processPacketAESF8(pkt);
+ break;
+ }
+
+ /*
+ * Update the rollover counter and highest sequence number if
+ * necessary.
+ */
+ update(seqNo, guessedIndex);
+
+ b = true;
}
- dropPkt = false;
}
- else
- {
- /*
- * Buffer.FLAG_SILENCE is set for RTP (as opposed to RTCP) audio (as
- * opposed to video) packets only.
- */
- dropPkt = true;
- }
-
- // Update the rollover counter and highest sequence number if necessary.
- update(seqNo, guessedIndex);
- return !dropPkt;
+ return b;
}
/**
@@ -978,13 +946,6 @@ private static synchronized void readConfigurationServicePropertiesOnce()
ConfigurationService cfg = LibJitsi.getConfigurationService();
if (cfg != null)
- {
checkReplay = cfg.getBoolean(CHECK_REPLAY_PNAME, checkReplay);
- dropMutedAudioSourceInReverseTransform
- = cfg.getBoolean(
- SsrcTransformEngine
- .DROP_MUTED_AUDIO_SOURCE_IN_REVERSE_TRANSFORM,
- dropMutedAudioSourceInReverseTransform);
- }
}
}