Return the i-th certificate provided by the peer.
Index 0 is the end entity certificate. Higher indexes are certificates
in the chain. Requesting an index higher than what is available returns
NULL.
The returned pointer is valid until the next mutating function call
affecting the connection. A mutating function call is one where the
first argument has type struct rustls_connection * (as opposed to
const struct rustls_connection *).
<https://docs.rs/rustls/0.20.0/rustls/enum.Connection.html#method.peer_certificates>
Return the i-th certificate provided by the peer. Index 0 is the end entity certificate. Higher indexes are certificates in the chain. Requesting an index higher than what is available returns NULL. The returned pointer is valid until the next mutating function call affecting the connection. A mutating function call is one where the first argument has type struct rustls_connection * (as opposed to const struct rustls_connection *). <https://docs.rs/rustls/0.20.0/rustls/enum.Connection.html#method.peer_certificates>