RTMP Handshake

After establishing a TCP connection, an RTMP connection is established first performing a handshake through the exchange of 3 packets from each side (also referred as Chunks in the official documentation). These are referred in the official spec as C0-2 for the client sent packets and S0-2 for the server side respectively and are not to be confused with RTMP packets that can be exchanged only after the handshake is complete. These packets have a structure of their own and C1 contains a field setting the "epoch" timestamp but since this can be set to zero, as is done in third party implementations, the packet can be simplified. The client initialises the connection by sending the C0 packet with a constant value of 0x03 representing the current protocol version. It follows straight with C1 without waiting for S0 to be received first which contains 1536 bytes, with the first 4 representing the epoch timestamp, the second 4 all being 0, and the rest being random (and which can be set to 0 in third party implementations). C2 and S2 are an echo of S1 and C1 respectively, except with the second 4 bytes being the time the respective message was received (instead of 0). After C2 and S2 are received the handshake is considered complete.