Speed up and secure Apache SSL encryption.

By default apache loads a bunch of encryption protocols. Most of which either are insecure and/or slow.

The location of these settings are based on DirectAdmin's Apache 2.4.x, however, you should easily be able to locate them in your apache .conf files.

vi /etc/httpd/conf/extra/httpd-ssl.conf

Set Apache to only use the fastest and best encryption algorithms.

Now comment out the default SSL settings and add new ones as shown below:

# Disable SSLv2
# Commented out below 3 lines:
# SSLProtocol All -SSLv2
# SSLHonorCipherOrder On
# SSLCipherSuite HIGH:!aNULL:!MD5

# Added the below 3 lines
SSLProtocol All -SSLv2
SSLHonorCipherOrder On
SSLCipherSuite ALL:!ADH:!EXP:!LOW:!RC2:!3DES:!SEED:!RC4:+HIGH:+MEDIUM

#   SSL Cipher Suite:
#   List the ciphers that the client is permitted to negotiate.
#   See the mod_ssl documentation for a complete list.
# SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL
# SSLCipherSuite ALL:-ADH:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP

# Commented out below 2 lines
# SSLHonorCipherOrder On
# SSLCipherSuite HIGH:!aNULL:!MD5

# Added below 2 lines
SSLHonorCipherOrder On
SSLCipherSuite ALL:!ADH:!EXP:!LOW:!RC2:!3DES:!SEED:!RC4:+HIGH:+MEDIUM

Disable Apache's Internet Explorer slow SSL settings used for outdated IE versions

For their own sake, people should not use old versions of IE.

# BrowserMatch ".*MSIE.*" \
#         nokeepalive ssl-unclean-shutdown \
#         downgrade-1.0 force-response-1.0

SetEnvIf User-Agent ".*MSIE [1-5].*" \
  nokeepalive ssl-unclean-shutdown \
  downgrade-1.0 force-response-1.0

SetEnvIf User-Agent ".*MSIE [6-9].*" \
  ssl-unclean-shutdown

 

Now restart apache and you should be all set.

service httpd restart

For reference, below is the entire httpd-ssl.conf

#
# This is the Apache server configuration file providing SSL support.
# It contains the configuration directives to instruct the server how to
# serve pages over an https connection. For detailing information about these 
# directives see 
# 
# Do NOT simply read the instructions in here without understanding
# what they do.  They're here only as hints or reminders.  If you are unsure
# consult the online docs. You have been warned.  
#

#
# 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 file:/dev/random  512
#SSLRandomSeed startup file:/dev/urandom 512
#SSLRandomSeed connect file:/dev/random  512
#SSLRandomSeed connect file:/dev/urandom 512


#
# When we also provide SSL we have to listen to the 
# standard HTTP port (see above) and to the HTTPS port
#
# Note: Configurations that use IPv6 but not IPv4-mapped addresses need two
#       Listen directives: "Listen [::]:443" and "Listen 0.0.0.0:443"
#
Listen 443

##
##  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  builtin

#   Inter-Process Session Cache:
#   Configure the SSL Session Cache: First the mechanism 
#   to use and second the expiring timeout (in seconds).
#SSLSessionCache         dbm:/var/logs/ssl_scache
SSLSessionCache        shmcb:/var/log/httpd/ssl_scache(512000)
SSLSessionCacheTimeout  300

#   Semaphore:
#   Configure the path to the mutual exclusion semaphore the
#   SSL engine uses internally for inter-process synchronization. 
#SSLMutex  file:/var/log/httpd/ssl_mutex

# Disable SSLv2
# KZN commented out below 3 lines:
#SSLProtocol All -SSLv2
#SSLHonorCipherOrder On
#SSLCipherSuite HIGH:!aNULL:!MD5
#kzn http://unhandledexpression.com/2013/01/25/5-easy-tips-to-accelerate-ssl/
SSLProtocol All -SSLv2
SSLHonorCipherOrder On
SSLCipherSuite ALL:!ADH:!EXP:!LOW:!RC2:!3DES:!SEED:!RC4:+HIGH:+MEDIUM

##
## SSL Virtual Host Context
##



#   General setup for the virtual host
DocumentRoot "/var/www/html"
ServerName www.example.com:443
ServerAdmin [email protected]
ErrorLog /var/log/httpd/error_log
TransferLog /var/log/httpd/access_log

#   SSL Engine Switch:
#   Enable/Disable SSL for this virtual host.
SSLEngine on

#   SSL Cipher Suite:
#   List the ciphers that the client is permitted to negotiate.
#   See the mod_ssl documentation for a complete list.
#SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL
#SSLCipherSuite ALL:-ADH:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP
#kzn removed below 2 lines
#SSLHonorCipherOrder On
#SSLCipherSuite HIGH:!aNULL:!MD5
#kzn http://unhandledexpression.com/2013/01/25/5-easy-tips-to-accelerate-ssl/
SSLHonorCipherOrder On
SSLCipherSuite ALL:!ADH:!EXP:!LOW:!RC2:!3DES:!SEED:!RC4:+HIGH:+MEDIUM


#   Server Certificate:
#   Point SSLCertificateFile at a PEM encoded certificate.  If
#   the certificate is encrypted, then you will be prompted for a
#   pass phrase.  Note that a kill -HUP will prompt again.  Keep
#   in mind that if you have both an RSA and a DSA certificate you
#   can configure both in parallel (to also allow the use of DSA
#   ciphers, etc.)
SSLCertificateFile /etc/httpd/conf/ssl.crt/server.crt
#SSLCertificateFile /etc/httpd/conf/server-dsa.crt

#   Server Private Key:
#   If the key is not combined with the certificate, use this
#   directive to point at the key file.  Keep in mind that if
#   you've both a RSA and a DSA private key you can configure
#   both in parallel (to also allow the use of DSA ciphers, etc.)
SSLCertificateKeyFile /etc/httpd/conf/ssl.key/server.key
#SSLCertificateKeyFile /etc/httpd/conf/server-dsa.key

#   Server Certificate Chain:
#   Point SSLCertificateChainFile at a file containing the
#   concatenation of PEM encoded CA certificates which form the
#   certificate chain for the server certificate. Alternatively
#   the referenced file can be the same as SSLCertificateFile
#   when the CA certificates are directly appended to the server
#   certificate for convinience.
#SSLCertificateChainFile /etc/httpd/conf/server-ca.crt

#   Certificate Authority (CA):
#   Set the CA certificate verification path where to find CA
#   certificates for client authentication or alternatively one
#   huge file containing all of them (file must be PEM encoded)
#   Note: Inside SSLCACertificatePath you need hash symlinks
#         to point to the certificate files. Use the provided
#         Makefile to update the hash symlinks after changes.
SSLCACertificateFile /etc/httpd/conf/ssl.crt/server.ca
#SSLCACertificatePath /etc/httpd/conf/ssl.crt
#SSLCACertificateFile /etc/httpd/conf/ssl.crt/ca-bundle.crt

#   Certificate Revocation Lists (CRL):
#   Set the CA revocation path where to find CA CRLs for client
#   authentication or alternatively one huge file containing all
#   of them (file must be PEM encoded)
#   Note: Inside SSLCARevocationPath you need hash symlinks
#         to point to the certificate files. Use the provided
#         Makefile to update the hash symlinks after changes.
#SSLCARevocationPath /etc/httpd/conf/ssl.crl
#SSLCARevocationFile /etc/httpd/conf/ssl.crl/ca-bundle.crl

#   Client Authentication (Type):
#   Client certificate verification type and depth.  Types are
#   none, optional, require and optional_no_ca.  Depth is a
#   number which specifies how deeply to verify the certificate
#   issuer chain before deciding the certificate is not valid.
#SSLVerifyClient require
#SSLVerifyDepth  10

#   Access Control:
#   With SSLRequire you can do per-directory access control based
#   on arbitrary complex boolean expressions containing server
#   variable checks and other lookup directives.  The syntax is a
#   mixture between C and Perl.  See the mod_ssl documentation
#   for more details.
#
#SSLRequire (    %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \
#            and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \
#            and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \
#            and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \
#            and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20       ) \
#           or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/
#

#   SSL Engine Options:
#   Set various options for the SSL engine.
#   o FakeBasicAuth:
#     Translate the client X.509 into a Basic Authorisation.  This means that
#     the standard Auth/DBMAuth methods can be used for access control.  The
#     user name is the `one line' version of the client's X.509 certificate.
#     Note that no password is obtained from the user. Every entry in the user
#     file needs this password: `xxj31ZMTZzkVA'.
#   o ExportCertData:
#     This exports two additional environment variables: SSL_CLIENT_CERT and
#     SSL_SERVER_CERT. These contain the PEM-encoded certificates of the
#     server (always existing) and the client (only existing when client
#     authentication is used). This can be used to import the certificates
#     into CGI scripts.
#   o StdEnvVars:
#     This exports the standard SSL/TLS related `SSL_*' environment variables.
#     Per default this exportation is switched off for performance reasons,
#     because the extraction step is an expensive operation and is usually
#     useless for serving static content. So one usually enables the
#     exportation for CGI and SSI requests only.
#   o StrictRequire:
#     This denies access when "SSLRequireSSL" or "SSLRequire" applied even
#     under a "Satisfy any" situation, i.e. when it applies access is denied
#     and no other module can change it.
#   o OptRenegotiate:
#     This enables optimized SSL connection renegotiation handling when SSL
#     directives are used in per-directory context. 
#SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire

    SSLOptions +StdEnvVars


Header set Cache-Control "max-age=31536000, public"


    SSLOptions +StdEnvVars


#   SSL Protocol Adjustments:
#   The safe and default but still SSL/TLS standard compliant shutdown
#   approach is that mod_ssl sends the close notify alert but doesn't wait for
#   the close notify alert from client. When you need a different shutdown
#   approach you can use one of the following variables:
#   o ssl-unclean-shutdown:
#     This forces an unclean shutdown when the connection is closed, i.e. no
#     SSL close notify alert is send or allowed to received.  This violates
#     the SSL/TLS standard but is needed for some brain-dead browsers. Use
#     this when you receive I/O errors because of the standard approach where
#     mod_ssl sends the close notify alert.
#   o ssl-accurate-shutdown:
#     This forces an accurate shutdown when the connection is closed, i.e. a
#     SSL close notify alert is send and mod_ssl waits for the close notify
#     alert of the client. This is 100% SSL/TLS standard compliant, but in
#     practice often causes hanging connections with brain-dead browsers. Use
#     this only for browsers where you know that their SSL implementation
#     works correctly. 
#   Notice: Most problems of broken clients are also related to the HTTP
#   keep-alive facility, so you usually additionally want to disable
#   keep-alive for those clients, too. Use variable "nokeepalive" for this.
#   Similarly, one has to force some clients to use HTTP/1.0 to workaround
#   their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and
#   "force-response-1.0" for this.
#
# kzn http://blog.vpire.com/822/apache-ssl-slow-on-internet-explorer/
#
# BrowserMatch ".*MSIE.*" \
#         nokeepalive ssl-unclean-shutdown \
#         downgrade-1.0 force-response-1.0

SetEnvIf User-Agent ".*MSIE [1-5].*" \
  nokeepalive ssl-unclean-shutdown \
  downgrade-1.0 force-response-1.0

SetEnvIf User-Agent ".*MSIE [6-9].*" \
  ssl-unclean-shutdown

#   Per-Server Logging:
#   The home of a custom SSL log file. Use this when you want a
#   compact non-error SSL logfile on a virtual host basis.
CustomLog /var/log/httpd/ssl_request_log \
          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"