Self Signed SSL Certificate using openssl

This post is heavily inspired by the following post

The setup is to enable a SSL in apache.

My Setup:
Mac OS: Mavericks
Webserver: Apache with modssl.
Apache location:/etc/apache2
Log Files: /var/log/apache2/

To enable SSL in apache, the following files needs to be changed.


create a folderĀ ssl
At the end of the exercise the below 2 files should be available in the above folder.

  • server.crt
  • server.key

Step 1: Generate a Private Key

The openssl toolkit is used to generate an RSA Private Key and CSR (Certificate Signing Request).
It can also be used to generate self-signed certificates which can be used for
testing purposes or internal usage.

The first step is to create your RSA Private Key.
This key is a 1024 bit RSA key which is encrypted using Triple-DES and stored in a
PEM format so that it is readable as ASCII text.

openssl genrsa -des3 -out server.key 1024
Generating RSA private key, 1024 bit long modulus
e is 65537 (0x10001)
Enter pass phrase for server.key:
Verifying - Enter pass phrase for server.key:

Step 2: Generate a CSR (Certificate Signing Request)
Once the private key is generated a Certificate Signing Request can be generated.
The CSR is then used in one of two ways. Ideally, the CSR will be sent to a
Certificate Authority, such as Thawte or Verisign who will verify the identity of the
requestor and issue a signed certificate. The second option is to self-sign the CSR,
which will be demonstrated in the next section.

During the generation of the CSR, you will be prompted for several pieces of information.
These are the X.509 attributes of the certificate. One of the prompts will be for
“Common Name (e.g., YOUR name)”. It is important that this field be filled in with
the fully qualified domain name of the server to be protected by SSL.

sudo openssl req -new -key server.key -out server.csr

Enter pass phrase for server.key:
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter ‘.’, the field will be left blank.
Country Name (2 letter code) [AU]:IN
State or Province Name (full name) [Some-State]:TN
Locality Name (eg, city) []:CHENNAI
Organization Name (eg, company) [Internet Widgits Pty Ltd]:MyCompany
Organizational Unit Name (eg, section) []:MyUnit
Common Name (e.g. server FQDN or YOUR name) []:venkat.local
Email Address []

Please enter the following ‘extra’ attributes
to be sent with your certificate request
A challenge password []:password
An optional company name []:password

Step 3: Remove Passphrase from Key
One unfortunate side-effect of the pass-phrased private key is that Apache will ask for
the pass-phrase each time the web server is started. Obviously this is not necessarily
convenient as someone will not always be around to type in the pass-phrase, such as after
a reboot or crash. mod_ssl includes the ability to use an external program in place of
the built-in pass-phrase dialog, however, this is not necessarily the most secure option
either. It is possible to remove the Triple-DES encryption from the key, thereby no
longer needing to type in a pass-phrase. If the private key is no longer encrypted,
it is critical that this file only be readable by the root user! If your system is ever
compromised and a third party obtains your unencrypted private key, the corresponding
certificate will need to be revoked. With that being said, use the following command
to remove the pass-phrase from the key:

sudo cp server.key
sudo openssl rsa -in -out server.key
Enter pass phrase for
writing RSA key

Step 4: Generating a Self-Signed Certificate

At this point you will need to generate a self-signed certificate because you either don’t
plan on having your certificate signed by a CA, or you wish to test your new SSL
implementation while the CA is signing your certificate. This temporary certificate
will generate an error in the client browser to the effect that the signing certificate
authority is unknown and not trusted.

To generate a temporary certificate which is good for 365 days, issue the following

sudo openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
Signature ok
Getting Private key

Step 5 Update the httpd-ssl.conf with the private key & certificate details.

# Server Certificate:
SSLCertificateFile "/etc/apache2/ssl/server.crt"
# Server Private Key:
SSLCertificateKeyFile "/etc/apache2/ssl/server.key"