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); } } }