ContentDigest directive and Content-MD5 header

The ContentDigest directive and support for the the Content-MD5 header has been removed from the server, corresponding with the removal of this header from RFC7231 Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content.

Listen directive options

The Listen directive now supports an optional options=... argument, allowing per-listener socket options to be configured.

systemd socket activation

httpd can now be configured to start via systemd socket activation.

New DefaultStateDir directive.

The DefaultStateDir directive has been added to specify a directory for storing persistent state.

Zone/scope support in IPv6 addresses

If built against APR 1.7.0 or later, zones (scopes) can be specified in an IPv6 link-local address used with the Listen or VirtualHost directive.

mod_journald, mod_syslog

These new modules provide support for logging to syslog or journald.

mod_ssl

The following mod_ssl enhancements are included:

• SSLRandomSeed directive is now deprecated and is ignored if building against OpenSSL 1.1.1 or later.
• The SSLKEYLOGFILE environment variable can now be set to log private key material for off-line decryption of SSL/TLS protocol dumps using third-party tools.

mod_cgid

If configured with --enable-cgid-fdpassing, the CGI daemon will set up stderr handling in the same way as mod_cgi.

htpasswd

The htpasswd utility can now generate SHA-256 or SHA-512 crypt() hashes where supported by the C library.

Fill me in

The mod_example documentation fill me in.

New type ap_method_mask_t.

The ap_method_mask_t type has been added and is now used for the method_mask field in ap_method_list_t, AP_METHOD_BIT, allowed field of request_rec, limited field of cmd_parms.

mod_ssl.h mod_ssl API changes.

The ssl_var_lookup optional function API now takes a const char *name argument and returns a const char * string value. The pool argument must now be non-NULL.

The developer documentation contains a detailed list of API changes.