3

on my file in /etc/httpd/conf.d/ssl.conf

I see

    #
# 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 

<URL:http://httpd.apache.org/docs/2.2/mod/mod_ssl.html>
#
# 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.
#

LoadModule ssl_module modules/mod_ssl.so

#
# When we also provide SSL we have to listen to the
# the HTTPS port in addition.
#
Listen 443

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

#   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         shmcb:/var/cache/mod_ssl/scache(512000)
SSLSessionCacheTimeout  300

#   Semaphore:
#   Configure the path to the mutual exclusion semaphore the
#   SSL engine uses internally for inter-process synchronization.
SSLMutex default

#   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/urandom  256
SSLRandomSeed connect builtin
#SSLRandomSeed startup file:/dev/random  512
#SSLRandomSeed connect file:/dev/random  512
#SSLRandomSeed connect file:/dev/urandom 512

#
# Use "SSLCryptoDevice" to enable any supported hardware
# accelerators. Use "openssl engine -v" to list supported
# engine names.  NOTE: If you enable an accelerator and the
# server does not start, consult the error logs and ensure
# your accelerator is functioning properly.
#
SSLCryptoDevice builtin
#SSLCryptoDevice ubsec

##
## SSL Virtual Host Context
##

#<VirtualHost _default_:443>
#
## General setup for the virtual host, inherited from global 

configuration
##DocumentRoot "/var/www/html"
##ServerName www.example.com:443
#
## Use separate log files for the SSL virtual host; note that LogLevel
## is not inherited from httpd.conf.
#ErrorLog logs/ssl_error_log
#TransferLog logs/ssl_access_log
#LogLevel warn
#
##   SSL Engine Switch:
##   Enable/Disable SSL for this virtual host.
#SSLEngine on
#
##   SSL Protocol support:
## List the enable protocol levels with which clients will be able to
## connect.  Disable SSLv2 access by default:
#SSLProtocol +TLSv1 +TLSv1.1 +TLSv1.2
#
##   SSL Cipher Suite:
## List the ciphers that the client is permitted to negotiate.
## See the mod_ssl documentation for a complete list.
#SSLCipherSuite HIGH:!aNULL:!MD5
#
##   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.  A new
## certificate can be generated using the genkey(1) command.
#SSLCertificateFile /etc/pki/tls/certs/localhost.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/pki/tls/private/localhost.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/pki/tls/certs/server-chain.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)
##SSLCACertificateFile /etc/pki/tls/certs/ca-bundle.crt
#
##   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.
##<Location />
##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]+$/
##</Location>
#
##   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: `xxj59ZMbhljvkA'.
##   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
#<Files ~ "\.(cgi|shtml|phtml|php3?)$">
#    SSLOptions +StdEnvVars
#</Files>
#<Directory "/var/www/cgi-bin">
#    SSLOptions +StdEnvVars
#</Directory>
#
##   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.
#SetEnvIf User-Agent ".*MSIE.*" \
#         nokeepalive ssl-unclean-shutdown \
#         downgrade-1.0 force-response-1.0
#
##   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 logs/ssl_request_log \
#          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
#
#</VirtualHost>

What should I change in order to disable SSLv2 and SSLv3?

1

Since you haven't provided specific versions, it's not technically possible to give a definitive answer, but the best tool I'm aware for configuring SSL on web servers is Mozilla's SSL Configuration Generator. I can't improve on what this tool provides, so it's best if you use it yourself.

From it's wiki page:

Security/Server Side TLS

The goal of this document is to help operational teams with the configuration of TLS on servers. [emphasis added] All Mozilla sites and deployment should follow the recommendations below.

The Operations Security (OpSec) team maintains this document as a reference guide to navigate the TLS landscape. It contains information on TLS protocols, known issues and vulnerabilities, configuration examples and testing tools. Changes are reviewed and merged by the OpSec team, and broadcasted to the various Operational teams.

...

From your stated desire to disable SSLv2 and SSLv3, you probably want the "intermediate" configuration for you versions of Apache and OpenSSL.

There are also some interesting notes about SSL parameters such as Diffie-Hellman key size. If you use too small of a DH key, later versions of OpenSSL and modern browsers can refuse to connect to your site even if other non-DH cipher suites are available.

  • are not very experienced, i see ## SSL Protocol support: ## List the enable protocol levels with which clients will be able to ## connect. Disable SSLv2 access by default: #SSLProtocol +TLSv1 +TLSv1.1 +TLSv1.2 I do not see ssl3, whi?? – prn86 Mar 8 '17 at 9:20

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