to authenticate the server against the client

to generate the premaster secret

to sign the Diffie Hellmann parameters

to encrypt the symmetric key

to ensure the integritiy of the data transfer

symmetric key

cipher suites

trusted CAs

private key

to mitigate MITM attacks

it is only needed for diffie hellman key exchange

https doesn't work without it

it is needed for asymmetric crypto

root certificate authority

root server

certificateion revocation list server

intermediate certificate authority

OCSP server

an alternative for the vhost in http3

to ensure perfect forward security

to get the correct certificate for the vhost

to get the server name

to enable named based vhosts