/**
* Copies the content of the most recently received packet into <tt>data</tt>.
*
* @param buffer an optional <tt>Buffer</tt> instance associated with the specified <tt>data</tt>,
* <tt>offset</tt> and <tt>length</tt> and provided to the method in case the implementation
* would like to provide additional <tt>Buffer</tt> properties such as <tt>flags</tt>
* @param data the <tt>byte[]</tt> that we'd like to copy the content of the packet to.
* @param offset the position where we are supposed to start writing in <tt>data</tt>.
* @param length the number of <tt>byte</tt>s available for writing in <tt>data</tt>.
* @return the number of bytes read
* @throws IOException if <tt>length</tt> is less than the size of the packet.
*/
protected int read(Buffer buffer, byte[] data, int offset, int length) throws IOException {
if (data == null) throw new NullPointerException("data");
if (ioError) return -1;
RawPacket pkt;
synchronized (pktSyncRoot) {
pkt = this.pkt;
this.pkt = null;
}
int pktLength;
if (pkt == null) {
pktLength = 0;
} else {
// By default, pkt will be returned to the pool after it was read.
boolean poolPkt = true;
try {
pktLength = pkt.getLength();
if (length < pktLength) {
/*
* If pkt is still the latest RawPacket made available to
* reading, reinstate it for the next invocation of read;
* otherwise, return it to the pool.
*/
poolPkt = false;
throw new IOException("Input buffer not big enough for " + pktLength);
} else {
byte[] pktBuffer = pkt.getBuffer();
if (pktBuffer == null) {
throw new NullPointerException(
"pkt.buffer null, pkt.length " + pktLength + ", pkt.offset " + pkt.getOffset());
} else {
System.arraycopy(pkt.getBuffer(), pkt.getOffset(), data, offset, pktLength);
if (buffer != null) buffer.setFlags(pkt.getFlags());
}
}
} finally {
if (!poolPkt) {
synchronized (pktSyncRoot) {
if (this.pkt == null) this.pkt = pkt;
else poolPkt = true;
}
}
if (poolPkt) {
// Return pkt to the pool because it was successfully read.
poolRawPacket(pkt);
}
}
}
return pktLength;
}
public int write(byte[] buffer, int offset, int length, boolean transform) {
RawPacket pkt = rawPacketArray[0];
if (pkt == null) pkt = new RawPacket();
rawPacketArray[0] = pkt;
byte[] pktBuf = pkt.getBuffer();
if (pktBuf == null || pktBuf.length < length) {
pktBuf = new byte[length];
pkt.setBuffer(pktBuf);
}
System.arraycopy(buffer, offset, pktBuf, 0, length);
pkt.setOffset(0);
pkt.setLength(length);
if (transform) {
PacketTransformer packetTransformer =
isControlStream ? rtcpPacketTransformer : rtpPacketTransformer;
if (packetTransformer != null)
rawPacketArray = packetTransformer.reverseTransform(rawPacketArray);
}
SourceTransferHandler transferHandler;
PushSourceStream pushSourceStream;
try {
if (isControlStream) {
transferHandler = controlTransferHandler;
pushSourceStream = getControlInputStream();
} else {
transferHandler = dataTransferHandler;
pushSourceStream = getDataInputStream();
}
} catch (IOException ioe) {
throw new UndeclaredThrowableException(ioe);
}
for (int i = 0; i < rawPacketArray.length; i++) {
RawPacket packet = rawPacketArray[i];
// keep the first element for reuse
if (i != 0) rawPacketArray[i] = null;
if (packet != null) {
if (isControlStream) pendingControlPacket = packet;
else pendingDataPacket = packet;
if (transferHandler != null) {
transferHandler.transferData(pushSourceStream);
}
}
}
return length;
}
/**
* Adds a <tt>DatagramPacketFilter</tt> which allows dropping <tt>DatagramPacket</tt>s before they
* are converted into <tt>RawPacket</tt>s.
*
* @param datagramPacketFilter the <tt>DatagramPacketFilter</tt> which allows dropping
* <tt>DatagramPacket</tt>s before they are converted into <tt>RawPacket</tt>s
*/
public synchronized void addDatagramPacketFilter(DatagramPacketFilter datagramPacketFilter) {
if (datagramPacketFilter == null) throw new NullPointerException("datagramPacketFilter");
if (datagramPacketFilters == null) {
datagramPacketFilters = new DatagramPacketFilter[] {datagramPacketFilter};
} else {
final int length = datagramPacketFilters.length;
for (int i = 0; i < length; i++)
if (datagramPacketFilter.equals(datagramPacketFilters[i])) return;
DatagramPacketFilter[] newDatagramPacketFilters = new DatagramPacketFilter[length + 1];
System.arraycopy(datagramPacketFilters, 0, newDatagramPacketFilters, 0, length);
newDatagramPacketFilters[length] = datagramPacketFilter;
datagramPacketFilters = newDatagramPacketFilters;
}
}
@Override
public int read(byte[] buffer, int offset, int length) throws IOException {
RawPacket pendingPacket;
if (isControlStream) {
pendingPacket = pendingControlPacket;
} else {
pendingPacket = pendingDataPacket;
}
int bytesToRead = 0;
byte[] pendingPacketBuffer = pendingPacket.getBuffer();
if (pendingPacketBuffer != null) {
int pendingPacketLength = pendingPacket.getLength();
bytesToRead = length > pendingPacketLength ? pendingPacketLength : length;
System.arraycopy(
pendingPacketBuffer, pendingPacket.getOffset(), buffer, offset, bytesToRead);
}
return bytesToRead;
}
/**
* Initializes a new <tt>SRTPTransformer</tt> instance with a specific (negotiated)
* <tt>SRTPProtectionProfile</tt> and the keying material specified by a specific
* <tt>TlsContext</tt>.
*
* @param srtpProtectionProfile the (negotiated) <tt>SRTPProtectionProfile</tt> to initialize the
* new instance with
* @param tlsContext the <tt>TlsContext</tt> which represents the keying material
* @return a new <tt>SRTPTransformer</tt> instance initialized with <tt>srtpProtectionProfile</tt>
* and <tt>tlsContext</tt>
*/
private SinglePacketTransformer initializeSRTPTransformer(
int srtpProtectionProfile, TlsContext tlsContext) {
boolean rtcp;
switch (componentID) {
case Component.RTCP:
rtcp = true;
break;
case Component.RTP:
rtcp = false;
break;
default:
throw new IllegalStateException("componentID");
}
int cipher_key_length;
int cipher_salt_length;
int cipher;
int auth_function;
int auth_key_length;
int RTCP_auth_tag_length, RTP_auth_tag_length;
switch (srtpProtectionProfile) {
case SRTPProtectionProfile.SRTP_AES128_CM_HMAC_SHA1_32:
cipher_key_length = 128 / 8;
cipher_salt_length = 112 / 8;
cipher = SRTPPolicy.AESCM_ENCRYPTION;
auth_function = SRTPPolicy.HMACSHA1_AUTHENTICATION;
auth_key_length = 160 / 8;
RTCP_auth_tag_length = 80 / 8;
RTP_auth_tag_length = 32 / 8;
break;
case SRTPProtectionProfile.SRTP_AES128_CM_HMAC_SHA1_80:
cipher_key_length = 128 / 8;
cipher_salt_length = 112 / 8;
cipher = SRTPPolicy.AESCM_ENCRYPTION;
auth_function = SRTPPolicy.HMACSHA1_AUTHENTICATION;
auth_key_length = 160 / 8;
RTCP_auth_tag_length = RTP_auth_tag_length = 80 / 8;
break;
case SRTPProtectionProfile.SRTP_NULL_HMAC_SHA1_32:
cipher_key_length = 0;
cipher_salt_length = 0;
cipher = SRTPPolicy.NULL_ENCRYPTION;
auth_function = SRTPPolicy.HMACSHA1_AUTHENTICATION;
auth_key_length = 160 / 8;
RTCP_auth_tag_length = 80 / 8;
RTP_auth_tag_length = 32 / 8;
break;
case SRTPProtectionProfile.SRTP_NULL_HMAC_SHA1_80:
cipher_key_length = 0;
cipher_salt_length = 0;
cipher = SRTPPolicy.NULL_ENCRYPTION;
auth_function = SRTPPolicy.HMACSHA1_AUTHENTICATION;
auth_key_length = 160 / 8;
RTCP_auth_tag_length = RTP_auth_tag_length = 80 / 8;
break;
default:
throw new IllegalArgumentException("srtpProtectionProfile");
}
byte[] keyingMaterial =
tlsContext.exportKeyingMaterial(
ExporterLabel.dtls_srtp, null, 2 * (cipher_key_length + cipher_salt_length));
byte[] client_write_SRTP_master_key = new byte[cipher_key_length];
byte[] server_write_SRTP_master_key = new byte[cipher_key_length];
byte[] client_write_SRTP_master_salt = new byte[cipher_salt_length];
byte[] server_write_SRTP_master_salt = new byte[cipher_salt_length];
byte[][] keyingMaterialValues = {
client_write_SRTP_master_key,
server_write_SRTP_master_key,
client_write_SRTP_master_salt,
server_write_SRTP_master_salt
};
for (int i = 0, keyingMaterialOffset = 0; i < keyingMaterialValues.length; i++) {
byte[] keyingMaterialValue = keyingMaterialValues[i];
System.arraycopy(
keyingMaterial, keyingMaterialOffset, keyingMaterialValue, 0, keyingMaterialValue.length);
keyingMaterialOffset += keyingMaterialValue.length;
}
SRTPPolicy srtcpPolicy =
new SRTPPolicy(
cipher,
cipher_key_length,
auth_function,
auth_key_length,
RTCP_auth_tag_length,
cipher_salt_length);
SRTPPolicy srtpPolicy =
new SRTPPolicy(
cipher,
cipher_key_length,
auth_function,
auth_key_length,
RTP_auth_tag_length,
cipher_salt_length);
SRTPContextFactory clientSRTPContextFactory =
new SRTPContextFactory(
/* sender */ tlsContext instanceof TlsClientContext,
client_write_SRTP_master_key,
client_write_SRTP_master_salt,
srtpPolicy,
srtcpPolicy);
SRTPContextFactory serverSRTPContextFactory =
new SRTPContextFactory(
/* sender */ tlsContext instanceof TlsServerContext,
server_write_SRTP_master_key,
server_write_SRTP_master_salt,
srtpPolicy,
srtcpPolicy);
SRTPContextFactory forwardSRTPContextFactory;
SRTPContextFactory reverseSRTPContextFactory;
if (tlsContext instanceof TlsClientContext) {
forwardSRTPContextFactory = clientSRTPContextFactory;
reverseSRTPContextFactory = serverSRTPContextFactory;
} else if (tlsContext instanceof TlsServerContext) {
forwardSRTPContextFactory = serverSRTPContextFactory;
reverseSRTPContextFactory = clientSRTPContextFactory;
} else {
throw new IllegalArgumentException("tlsContext");
}
SinglePacketTransformer srtpTransformer;
if (rtcp) {
srtpTransformer = new SRTCPTransformer(forwardSRTPContextFactory, reverseSRTPContextFactory);
} else {
srtpTransformer = new SRTPTransformer(forwardSRTPContextFactory, reverseSRTPContextFactory);
}
return srtpTransformer;
}
