Used the following mechanism to generate a CSR needed to buy an SSL certificate. The server in this case was a Linux server and certificate was a “wildcard certificate” purchased at GoDaddy.com
# openssl req -nodes -newkey rsa:2048 -keyout server.key -out server.csr
Generating a 2048 bit RSA private key
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writing new private key to 'server.key'
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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.
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Country Name (2 letter code) [XX]:US
State or Province Name (full name) []:California
Locality Name (eg, city) [Default City]:Los Angeles
Organization Name (eg, company) [Default Company Ltd]:Acme
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:*.acme.com
Email Address []:admin@acme.com
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:
At this point, two files were created.
# ll total 8 -rw-r--r-- 1 root root 1054 Dec 28 03:31 server.csr -rw-r--r-- 1 root root 1704 Dec 28 03:31 server.key
The csr file can be used to purchase the certificate.