apache2/mods-available/ssl.conf



<IfModule mod_ssl.c>

    # Pseudo Random Number Generator (PRNG):
    # Configure one or more sources to seed the PRNG of the SSL library.
    # The seed data should be of good random quality.
    # WARNING! On some platforms /dev/random blocks if not enough entropy
    # is available. This means you then cannot use the /dev/random device
    # because it would lead to very long connection times (as long as
    # it requires to make more entropy available). But usually those
    # platforms additionally provide a /dev/urandom device which doesn't
    # block. So, if available, use this one instead. Read the mod_ssl User
    # Manual for more details.
    #
    SSLRandomSeed startup builtin
    SSLRandomSeed startup file:/dev/urandom 512
    SSLRandomSeed connect builtin
    SSLRandomSeed connect file:/dev/urandom 512

    ##
    ##  SSL Global Context
    ##
    ##  All SSL configuration in this context applies both to
    ##  the main server and all SSL-enabled virtual hosts.
    ##

    #
    #   Some MIME-types for downloading Certificates and CRLs
    #
    AddType application/x-x509-ca-cert .crt
    AddType application/x-pkcs7-crl .crl

    #   Pass Phrase Dialog:
    #   Configure the pass phrase gathering process.
    #   The filtering dialog program (`builtin' is a internal
    #   terminal dialog) has to provide the pass phrase on stdout.
    SSLPassPhraseDialog  exec:/usr/share/apache2/ask-for-passphrase

    #   Inter-Process Session Cache:
    #   Configure the SSL Session Cache: First the mechanism 
    #   to use and second the expiring timeout (in seconds).
    #   (The mechanism dbm has known memory leaks and should not be used).
    #SSLSessionCache         dbm:${APACHE_RUN_DIR}/ssl_scache
    SSLSessionCache  shmcb:${APACHE_RUN_DIR}/ssl_scache(512000)
    SSLSessionCacheTimeout  300

    #   Semaphore:
    #   Configure the path to the mutual exclusion semaphore the
    #   SSL engine uses internally for inter-process synchronization. 
    #   (Disabled by default, the global Mutex directive consolidates by default
    #   this)
    #Mutex file:${APACHE_LOCK_DIR}/ssl_mutex ssl-cache


    #   SSL Cipher Suite:
    #   List the ciphers that the client is permitted to negotiate. See the
    #   ciphers(1) man page from the openssl package for list of all available
    #   options.
    #   Enable only secure ciphers:
    #   More info: <https://scotthelme.co.uk/https-cheat-sheet/>
    SSLCipherSuite EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH

    # SSL server cipher order preference:
    # Use server priorities for cipher algorithm choice.
    # Clients may prefer lower grade encryption.  You should enable this
    # option if you want to enforce stronger encryption, and can afford
    # the CPU cost, and did not override SSLCipherSuite in a way that puts
    # insecure ciphers first.
    # Default: Off
    SSLHonorCipherOrder on

    #   The protocols to enable.
    #   Available values: all, SSLv3, TLSv1, TLSv1.1, TLSv1.2, TLSv1.3
    #   SSL v2  is no longer supported
    SSLProtocol all -SSLv3 -TLSv1 -TLSv1.1

    #   Allow insecure renegotiation with clients which do not yet support the
    #   secure renegotiation protocol. Default: Off
    #SSLInsecureRenegotiation on

    #   Whether to forbid non-SNI clients to access name based virtual hosts.
    #   Default: Off
    #SSLStrictSNIVHostCheck On

    SSLUseStapling On
    SSLStaplingCache "shmcb:${APACHE_RUN_DIR}/ssl_stapling(32768)"

</IfModule>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet