SSL VPN
In an SSL VPN, we use a typical mechanism, with the delivery protocol (SSL/TLS) working on a higher level of the TCP/IP stack than the payload protocols (TCP/UDP) as shown in the following diagram:
Transport Layer Security (TLS) and the older protocol, Secure Sockets Layer (SSL), are cryptographic protocols based on X.509 digital certificates. For example, every time we access a website that uses HTTPS (such as a secure banking website, for example), we are working over an SSL/TLS secured connection. The process to set up the connection is called "SSL Handshake". It is a client-server process that we are able to divide into five steps:
A user (or computer) starts the communication requiring an SSL connection.
The server will send its SSL certificate, including the server's public key.
The client verifies the certificate and if it is valid, creates, encrypts, and sends back a symmetric session key using the server's public key.
The server decrypts the symmetric session key using its private...
