disabled by default, but can be enabled
(session tickets should be preferred)
applies to mod_openssl, mod_wolfssl, mod_nss
session cache is not currently implemented in mod_mbedtls or mod_gnutls
need to build wolfSSL library with --enable-alpn for ALPN
even if already building wolfSSL library with --enable-openssall
(sigh)
ALPN is required by the HTTP/2 specification
crippled functionality if wolfssl library not built --enable-opensslall
* SNI not handled since SNI callbacks are disabled in wolfSSL library
unless the wolfSSL library is built with --enable-openssall
This means that there is only one certificate per listening socket --
no certificate selection based on server name indication (SNI)
and is additionally a violation of the HTTP/2 specification,
which requires SNI.
slightly reduced functionality if wolfssl not built --enable-opensslall
* disable client certificate verification (error out if in lighttpd.conf)
* omit SSL_CIPHER_USEKEYSIZE, SSL_CIPHER_ALGKEYSIZE env vars
wolfSSL_CTX_set_mode() differs from openssl SSL_CTX_set_mode().
wolfSSL_CTX_set_mode() takes a single flag at a time and has
sparse flag support (small number of recognized flags)