public byte[] ReverseTransform(byte[] pkt, int offset, int length)
{
// Wrap data into the raw packet for readable format
this.rawPacket.Wrap(pkt, offset, length);
// Associate packet to a crypto context
long ssrc = this.rawPacket.GetSSRC();
SrtpCryptoContext context = null;
this.contexts.TryGetValue(ssrc, out context);
if (context == null)
{
context = this.reverseEngine.GetDefaultContext().deriveContext(ssrc, 0, 0);
context.DeriveSrtpKeys(this.rawPacket.GetSequenceNumber());
contexts[ssrc] = context;
}
bool reversed = context.ReverseTransformPacket(this.rawPacket);
if (reversed)
{
return(this.rawPacket.GetData());
}
return(null);
}
public byte[] ReverseTransform(byte[] pkt, int offset, int length)
{
var isLocked = Interlocked.CompareExchange(ref _isLocked, 1, 0) != 0;
try
{
// Wrap data into the raw packet for readable format
var rawPacket = !isLocked ? this.rawPacket : new RawPacket();
rawPacket.Wrap(pkt, offset, length);
// Associate packet to a crypto context
long ssrc = rawPacket.GetSSRC();
SrtpCryptoContext context = null;
this.contexts.TryGetValue(ssrc, out context);
if (context == null)
{
context = this.reverseEngine.GetDefaultContext().deriveContext(ssrc, 0, 0);
context.DeriveSrtpKeys(rawPacket.GetSequenceNumber());
contexts.AddOrUpdate(ssrc, context, (a, b) => context);
}
byte[] result = null;
bool reversed = context.ReverseTransformPacket(rawPacket);
if (reversed)
{
result = rawPacket.GetData();
}
return(result);
}
finally
{
//Unlock
if (!isLocked)
{
Interlocked.CompareExchange(ref _isLocked, 0, 1);
}
}
}
