Feb 19, 2024

Java Keytool - Generate CSR

Introduction

Java Keytool can be used to generate Java keystores, certificate signing requests (CSRs), convert certificate formats, and other certificate related functions. Keytool is bundled with Oracle's JDK. This article will walk through generating a CSR as well as generating a private key if one is not already available. 
 

Instructions

1. Generate a keystore:

A keypair must first exist in order to generate a CSR. If you have an existing Java keystore, proceed to the next step, otherwise use the command below to generate a new Java keystore:

keytool -genkey -alias mydomain -keyalg RSA -keystore KeyStore.jks -keysize 2048

Enter keystore password: <create keystore password>
Re-Enter new password: <confirm keystore password>

You now have a Java keystore from which you can generate a CSR.

Note: You can change the Alias of mydomain to a word of your choosing. This alias must remain the same for key generation, CSR generation, and signed public key importing. 

 

2. Generate a CSR:

keytool -certreq -alias mydomain -keystore KeyStore.jks -file mydomain.csr

Answer each question when prompted.
Use the chart below to guide you through the process:
 

Confirm or reject the details by typing "Yes" or "No" and pressing Enter

Press Enter to use the same password as the keystore, alternatively specify a separate password and press enter. 

You should now have a file called mydomain.csr which can be used to request a digital certificate from GlobalSign.