Active Streaming – https:
With PSL, connection that is encrypted with SSL (TLS) was not supported, the reason for this is that the encryption keys are known only to the Client and Server since they are the one that initiated the connection (preformed the SSL handshake), because of this we couldn’t get the data out of the packet and the application couldn’t scan it for malicious information. CPAS plays the rule of “man in the middle”, because of this, it can intercept the SSL handshake and change the keys so he will be able to understand the encryption. The Client preform an SSL handshake with the gateway (thinking it is the Server) while the Server preform SSL handshake with the gateway (thinking he is the Client). The gateway have both keys and he’s able to open the encryption, check the packet and re-encrypt the packet with the corresponding keys. In order to encrypt / decrypt the SSL connection, CPAS add another layer before the application queue. The new layer will send the packet to the SSL engine for decryption/encryption and then resume the normal flow.
Active Streaming – https content step by step:
Packets of SSL handshake are passed to the SSL engine to exchange keys. When the connection and the SSL handshake is fully established, an hook will be register for this connection to handle the decrypt / encrypt of the packets. When a packet arrive to CPAS, a trap will be sent and the SSL engine will receive the encrypted packet, decode the packet and return it to CPAS. The packet will enter the receive queue and the application will be able to work on it, once he done he will send it to the write queue. The packet will pass to the SSL engine for encryption and pass to the other side (Client, Server).
More read here:
R80.x - Security Gateway Architecture (Content Inspection)
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