How to generate a new private key with a public key and generate a CSR (Certificate Signing Request) using a single OpenSSL "req" command?

If you do not have a pair of private key and public key, and you want to generate CSR (Certificate Signing Request) to represent your personal identity or server identity, you can use the OpenSSL "req -newkey" command as shown below. The same command will generate a pair of RSA private key and public key for you too.

C:\Users\fyicenter>\local\openssl\openssl.exe

OpenSSL> req -newkey rsa:1024 -keyout rsa_test.key -out rsa_test.csr
Generating a 1024 bit RSA private key
......................................................++++++
...................++++++
writing new private key to 'rsa_test.key'
Enter PEM pass phrase: fyicenter
Verifying - Enter PEM pass phrase: fyicenter
-----
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]:us
State or Province Name (full name) [Some-State]:NY
Locality Name (eg, city) []:New York
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Donald Inc.
Organizational Unit Name (eg, section) []:IT
Common Name (e.g. server FQDN or YOUR name) []:www.donald.inc
Email Address []:john@donald.inc

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

OpenSSL> exit

C:\Users\fyicenter>type rsa_test.csr
-----BEGIN CERTIFICATE REQUEST-----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-----END CERTIFICATE REQUEST-----

Options used in this "req" command are:

• "-newkey rsa:1024" - Generate a pair of 1024-bit RSA private key with public key, and generate a new CSR.
• "-keyout rsa_test.key" - Save the pair of RSA private key with public key to the given file.
• "-out rsa_test.csr" - Save output, CSR, to the given file.
• "fyicenter" - Password to protect the RSA private key file and the CSR file.

⇒ OpenSSL "req -new -x509" - Generate Self-Signed Certificate

⇐ OpenSSL "req -pubkey" - Extract Public Key from CSR

⇑ OpenSSL "req" Command

⇑⇑ OpenSSL Tutorials