struct {
      opaque identity<1..2^16-1>;
      uint32 obfuscated_ticket_age;
  } PskIdentity;

  opaque PskBinderEntry<32..255>;

  struct {
      PskIdentity identities<7..2^16-1>;
      PskBinderEntry binders<33..2^16-1>;
  } OfferedPsks;

  struct {
      select (Handshake.msg_type) {
          case client_hello: OfferedPsks;
          case server_hello: uint16 selected_identity;
      };
  } PreSharedKeyExtension;