# Linux - Setting up an SSL secured Webserver with CentOS

This guide will explain how to set up a site over https. The tutorial uses a self signed key so will work well for a personal website or testing purposes. This is provided as is so proceed at your own risk and take backups!

## 1. 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.

```shell
yum install mod_ssl openssl
```

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

## 2. Generate a self-signed certificate

Using OpenSSL we will generate a self-signed certificate. If you are using this on a production server you are probably likely to want a key from a 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

```shell
# Generate private key 
openssl genrsa -out ca.key 2048 

# 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

# Copy the files to the correct locations
cp ca.crt /etc/pki/tls/certs
cp ca.key /etc/pki/tls/private/ca.key
cp ca.csr /etc/pki/tls/private/ca.csr
```

<table data-autosize="false" data-layout="default" data-number-column="false" data-table-local-id="96eecefd-44e7-4ae1-84e4-9ff6c1b12cf0" data-table-width="760" id="bkmrk-%C2%A0-warning%3A-make-sure"><tbody><tr><td class="pm-table-cell-content-wrap" data-cell-background="#ffcccc" data-colwidth="340"> </td><td class="pm-table-cell-content-wrap" colspan="2" data-cell-background="#ffcccc" data-colwidth="340,140">**WARNING:** Make sure that you **copy** the files and do not **move** them if you use SELinux. Apache will complain about missing certificate files otherwise, as it cannot read them because the certificate files do not have the right SELinux context.

</td></tr></tbody></table>

If you have moved the files and not copied them, you can use the following command to correct the SELinux contexts on those files, as the correct context definitions for /etc/pki/\* come with the bundled SELinux policy.

```shell
restorecon -RvF /etc/pki
```

Then we need to update the Apache SSL configuration file

```shell
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

```shell
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:

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

Quit and save the file and then restart Apache

```shell
/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.

## 3. Setting up the virtual hosts

Just as you set [VirtualHosts](https://wiki.centos.org/VirtualHosts.html) for http on port 80 so you do for https on port 443. A typical [VirtualHost](https://wiki.centos.org/VirtualHost.html) for a site on port 80 looks like this

```shell
<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

```shell
NameVirtualHost *:443
```

and then a [VirtualHost](https://wiki.centos.org/VirtualHost.html) record something like this:

```shell
<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

```shell
/etc/init.d/httpd restart
```

## 4. Configuring the firewall

You should now have a site working over https using a self-signed certificate. If you can't connect you may need to open the port on your firewall. To do this amend your iptables rules:

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