Ssl – Generating SSL certificates

opensslsslssl-certificate

I was wondering if anyone has any idea in how to generate a signed CA cert and key using openssl? I have found this website (http://dev.mysql.com/doc/refman/5.1/en/secure-create-certs.html) to generate the client and server certs for mysql server but the example is a self-signed certificate. I use the following command for running the server and client using openssl and the generated certs and keys:

openssl s_server -accept 6502 -cert server-cert.pem -key server-key.pem -CAfile ca-cert.pem -www

openssl s_client -connect 192.168.1.92:6502 -cert client-cert.pem -key client-key.pem -CAfile ca-cert.pem

The error output I get is "Verify return code: 18 (self signed certificate)".

Paul

Best Answer

Create Root CA (self-signed):

Let's have a look at the options in detail:

  • x509 identifies that a certificate is required, rather than just a certificate request (see below).
  • days 30000 sets the certificate to expire in a 30000 days. You may want to extend this period. Make a note of the expiry date so that you can renew it when necessary!
  • sha1 specifies that SHA1 encryption should be used. rsa:2048 sets the key as 2048 bit RSA.
  • nodes specifies no passphrase.
  • keyout and -out specify where to store the certificate and key. The key should be root-readable only; the certificate can be world-readable, and must be readable by the user that Apache runs as.
  • subj flag sets the company name, department name, and the web site address. If you leave these out, you'll be prompted for them. The CN must be the same as the address of your web site, otherwise the certificate won't match and users will receive a warning when connecting. Make sure you don't use a challenge password.

Create it :

sudo openssl req -x509 -nodes -newkey rsa:2048 -sha1 -keyout rootkey.key -out rootca.crt -passin pass:root -days 30000 -subj "/C=DU/ST=Dubai/L=TownCenter/O=AmesCom/CN=AmesCom Int" -config openssl.cnf.my

Encrypt the key manually :

key is not encrypted because of -nodes option , so we encrypt it manually :

sudo cp rootkey.key rootkey.key.org

sudo openssl rsa -in rootkey.key.org -out rootkey.key

Test it :

for testing immediately , you may follow two ways :

openssl x509 -text -noout -in rootca.crt 

or examine its contents on browser :

cp rootca.crt /var/www/html/

from browser ask for address :

http://yourserverdomain/rootca.crt

Now you can create certificate requests and sign them with this self-signed certificate