How to set the Bit Length when generating SSL Certificat with Java keytool?

Question

I'm going to create a SSL Certificate so I can use https on my web site. I have to generate a Certificate Signing Request (CSR) and I did generate such a file with the Java keytool following the guide Generate a Certificate Signing Request (CSR) on Tomcat, but when I upload my CSR, I get a message from GlobalSign:

We suggest that a Bit Length of 2048 bits is used when generating your CSR. Please regenerate your CSR and select this Bit Length.

So how do I set the Bit Length to 2048 bits using the Java keytool?

I generated the CSR file with: keytool -certreq -keyalg RSA -alias your_alias_name -file certreq.csr -keystore your_keystore_filename

And before that I created my certificate keystore and private key with: keytool -genkey -alias your_alaias_name -keyalg RSA -keystore your_keystore_filename

Answer 1

Try adding -keysize 2048

Source: CSR Generation: Java-based Webservers (using keytool)