3.5.2 Authentication

The key exchange algorithms of the TLS protocol offer authentication, which is a prerequisite for a secure connection. The available authentication methods in GnuTLS, under TLS 1.3 or earlier versions, follow.

• Certificate authentication: Authenticated key exchange using public key infrastructure and X.509 certificates.
• PSK authentication: Authenticated key exchange using a pre-shared key.

Under TLS 1.2 or earlier versions, the following authentication methods are also available.

• SRP authentication: Authenticated key exchange using a password.
• Anonymous authentication: Key exchange without peer authentication.