LoadModule fcgid_module modules/mod_fcgid.so
# (snip)
AddHandler fcgid-script .fcgi
SocketPath /tmp/trac-fastcgi.socket
ScriptAlias /trac /usr/local/app/trac/share/trac/cgi-bin/trac.fcgi
DefaultInitEnv TRAC_ENV_PARENT_DIR "/home/trac"
<Location ~ "^/trac/.*/login">
# ここで認証かける
</Location>