How to create a self-signed SSL Certificate

Posted: 0p in Linux

Overview
Normal web traffic is sent unencrypted over the Internet. That is, anyone with access to the right tools can snoop all of that traffic. Obviously, this can lead to problems, especially where security and privacy is necessary, such as in credit card data and bank transactions. The Secure Socket Layer is used to encrypt the data stream between the web server and the web client (the browser).
SSL makes use of what is known as asymmetric cryptography, commonly referred to as public key cryptography (PKI). With public key cryptography, two keys are created, one public, one private. Anything encrypted with either key can only be decrypted with its corresponding key. Thus if a message or data stream were encrypted with the server’s private key, it can be decrypted only using its corresponding public key, ensuring that the data only could have come from the server.
If SSL utilizes public key cryptography to encrypt the data stream traveling over the Internet, why is a certificate necessary? The technical answer to that question is that a certificate is not really necessary- the data is secure and cannot easily be decrypted by a third party. However, certificates do serve a crucial role in the communication process. The certificate, signed by a trusted Certificate Authority (CA), ensures that the certificate holder is really who he claims to be. Without a trusted signed certificate, your data may be encrypted, however, the party you are communicating with may not be whom you think. Without certificates, impersonation attacks would be much more common.
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 PEM pass phrase:
Verifying password – Enter PEM pass phrase:
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. If the website to be protected will be https://public.akadia.com, then enter public.akadia.com at this prompt. The command to generate the CSR is as follows:
openssl req -new -key server.key -out server.csr

Country Name (2 letter code) [GB]:IN
State or Province Name (full name) [Berkshire]:Kerala
Locality Name (eg, city) [Newbury]:Cochin
Organization Name (eg, company) [My Company Ltd]:Admin
Organizational Unit Name (eg, section) []:Information Technology
Common Name (eg, your name or your server’s hostname) []:testssl.com
Email Address []:test@testssl.com
Please enter the following ‘extra’ attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

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:
cp server.key server.key.org
openssl rsa -in server.key.org -out server.key
The newly created server.key file has no more passphrase in it.
-rw-r–r– 1 root root 745 Jun 29 12:19 server.csr
-rw-r–r– 1 root root 891 Jun 29 13:22 server.key
-rw-r–r– 1 root root 963 Jun 29 13:22 server.key.org
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 command:
openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
Signature ok
subject=/C=IN/ST=Kerala/L=Cochin/O=Admin/OU=Information
Technology/CN=testssl.com/Email=test@testssl.com
Getting Private key
Step 5: Installing the Private Key and Certificate
When Apache with mod_ssl is installed, it creates several directories in the Apache config directory. The location of this directory will differ depending on how Apache was compiled.
cp server.crt /usr/local/apache/conf/ssl.crt
cp server.key /usr/local/apache/conf/ssl.key
Step 6: Configuring SSL Enabled Virtual Hosts
SSLEngine on
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key
SetEnvIf User-Agent “.*MSIE.*” nokeepalive ssl-unclean-shutdown
CustomLog logs/ssl_request_log \
“%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \”%r\” %b”
Step 7: Restart Apache and Test
/etc/init.d/httpd stop
/etc/init.d/httpd start
================================================================

Advertisements
Comments
  1. I am usually to running a blog and i actually admire your content. The article has really peaks my interest. I’m going to bookmark your web site and hold checking for brand spanking new information.

  2. HCG diet says:

    I’ve found myself here several times before while looking various things. I appreciate the detailed articles you write, and in some cases this is the ONLY place I can even find them. Cheers

  3. Thank you for the details. I totally agree with everything you declare. My cousin is actually crafting a term paper on the exact same issue and I will post him the site to get a few tips from your writing. Or else, he might simply write my paper. I appreciate you for the article once more!

  4. Really great visual appeal on this website, I’d rate the application 10 12.

  5. Wonderful blog! I found it while browsing on Yahoo News. Do you have any suggestions on how to get listed in Yahoo News? I’ve been trying for a while but I never seem to get there! Thanks

  6. HCG dieting says:

    Excellent article. I really enjoyed reading it. I have been a fairly constant visitor of your website of late, as you always have lots of great info, however I thought I would finally change from lurker to commenter 🙂 Have a good one, look forward to seeing more!

  7. Hcg Drops Canada Reviews says:

    Hi Dear, are you really visiting this website regularly, if
    so then you will absolutely take pleasant know-how.

  8. It’s actually a coo and helpful piece off information.
    I am glad tjat you shared this helpful info with us.
    Please stay us up tto date like this. Thanks for sharing.

  9. I just like the valuable info you supply on your articles.

    I’ll bookmark your weblog aand test onde more right here frequently.
    I’m fairly sure I will be informed lots of neew stuff right right here!
    Best off luck for the next!

  10. miami movers says:

    Ԍoood wayy of tellіng,and fastidious aгticle to oƄtain facts egarding my
    presentatioon subject mɑtteг, which i am going to deliver iո
    college.

  11. This is really interesting, You’re a very skilled blogger.

    I’ve joined your rss feed and look forward to seeking more of your
    great post. Also, I’ve shared your site in my social networks!

  12. Εxcеllent, wҺat a webpage it is! Τhis weblog presents
    valuaƄlе facts to us, keep it uƿ.

  13. It’s going to be ending of mine day, except before end I am reading this impressive piece of writing to improve my experience.

  14. Thanks for a marvelous posting! I really enjoyed reading it, you can be
    a great author. I will be sure to bookmark your blog and will come back very soon. I want to encourage that you continue your great work, have
    a nice weekend!

  15. Thanks to my father who stated to me concerning
    this weblog, this website is in fact remarkable.

  16. here says:

    Wow, marvelous blog layout! How long have you been blogging for?
    you made blogging look easy. The overall look of your website is fantastic, as wll aas the content!

  17. Spot upon using this write-up, I truly think this site needs much more consideration. I’ll probably be again to study much more, thanks for that will info.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s