Getting the required software

For an SSL encrypted web server you will need a few things. Depending on your install you may or may not have OpenSSL and mod_ssl, Apache’s interface to OpenSSL.

Use yum to get them if you need them.

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yum install mod_ssl openssl

Yum will either tell you they are installed or will install them for you.

Generate a self-signed certificate

Using OpenSSL we will generate a self-signed certificate. If you are using this on a production server you will need a key from Trusted Certificate Authority, but if you are just using this on a personal site or for testing purposes a self-signed certificate is fine. To create the key you will need to be root so you can either su to root or use sudo in front of the commands

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openssl genrsa -out ca.key 1024 # Generate private key 

# Generate CSR 
openssl req -new -key ca.key -out ca.csr

# Generate Self Signed Key
openssl x509 -req -days 365 -in ca.csr -signkey ca.key -out ca.crt

# Move the files to the correct locations
mv ca.crt /etc/pki/tls/certs
mv ca.key /etc/pki/tls/private/ca.key
mv ca.csr /etc/pki/tls/private/ca.csr

Then we need to update the Apache SSL configuration file

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vi +/SSLCertificateFile /etc/httpd/conf.d/ssl.conf

Change the paths to match where the Key file is stored. If you’ve used the method above it will be

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SSLCertificateFile /etc/pki/tls/certs/ca.crt

Then set the correct path for the Certificate Key File a few lines below. If you’ve followed the instructions above it is:

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SSLCertificateKeyFile /etc/pki/tls/private/ca.key

Quit and save the file and then restart Apache

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/etc/init.d/httpd restart

All being well you should now be able to connect over https to your server and see a default Centos page. As the certificate is self signed browsers will generally ask you whether you want to accept the certificate. Firefox 3 won’t let you connect at all but you can override this.

Setting up the virtual hosts

Just as you set virtual hosts for http on port 80 so you do for https on port 433. A typical virtual host for a site on port 80 looks like this

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<VirtualHost *:80>
        <Directory /var/www/vhosts/yoursite.com/httpdocs>
        AllowOverride All
        </Directory>
        DocumentRoot /var/www/vhosts/yoursite.com/httpdocs
        ServerName yoursite.com
</VirtualHost>

To add a sister site on port 443 you need to add the following at the top of your file

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NameVirtualHost *:443

and then a VirtualHost record something like this:

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<VirtualHost *:443>
        SSLEngine on
        SSLCertificateFile /etc/pki/tls/certs/ca.crt
        SSLCertificateKeyFile /etc/pki/tls/private/ca.key
        <Directory /var/www/vhosts/yoursite.com/httpsdocs>
        AllowOverride All
        </Directory>
        DocumentRoot /var/www/vhosts/yoursite.com/httpsdocs
        ServerName yoursite.com
</VirtualHost>

Restart Apache again using

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/etc/init.d/httpd restart

You should now have a site working over https. If you can’t connect you probably need to open the port on your firewall:

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iptables -A INPUT -p tcp --dport 443 -j ACCEPT /sbin/service iptables save iptables -L -v