Can you explain the process of establishing a secure connection between a client and a server via the HTTPS protocol, including the handshake phase?

When establishing a secure connection via HTTPS, several key stages occur, including the TLS handshake phase:

1. Connection initiation: The client sends a request to the server to establish a secure connection, indicating supported TLS versions and cipher suites.

2. Server response: The server selects encryption parameters and sends its digital certificate, containing the public key and confirming its authenticity (issued by a certification authority).

3. Certificate verification: The client verifies the server's certificate for authenticity, validity period, and domain match.

4. Key exchange: The client generates a session secret key (e.g., using Diffie-Hellman or RSA algorithm), encrypts it with the server's public key, and sends it back.

5. Session key establishment: Both parties use the secret key for symmetric encryption of data.

6. Handshake completion: The client and server confirm the successful establishment of a secure channel and begin exchanging encrypted data.

Thus, the TLS handshake ensures server authentication, negotiation of encryption parameters, and secure key exchange to protect data in HTTPS.