Java Code Signing Certificate — Secure Your Java Applications

Java is one of the most popular languages used by developers to build software. A lot of the everyday applications we use, such as social media platforms, popular desktop applications, and large parts of Android, use Java or were built using it. A Java code signing certificate helps to assert the identity of the software publisher to the end users and affirms file integrity. Essentially, it assures customers that an attacker has not modified the program after it has been signed by the publisher, and that the publisher is legitimate.

If you wish to purchase Java code signing certificates, Sectigo has some good options at discounted rates and, what’s more, it comes with a 30-day money back guarantee!

Let’s dive into the process of buying and installing a Java code signing certificate on your server.

Prerequisites for Installing Java Code Signing Certificate

Before installing a Java code signing certificate, be sure to install the Java Development Kit (JDK) on your server or the local machine. The keytool utility is distributed with JDK/JRE and will be used to execute the commands in the following sections. For Windows server, ensure that the JDK bin folder is in the PATH environment (Example – C:\Program Files\Java\jdk1.7.0_02\bin) and if you change the directory (CD) to the JDK bin folder, you can use the keytool directly from there.

Creating a Java KeyStore

The steps below will help you to create a KeyStore that will be required during the certificate signing request (CSR) generation as well as while installing the certificate.

1. Create a Certificate KeyStore and Private Key

To create both of these items, run the following command:

keytool -genkey -alias alias_name -keyalg RSA -keystore keystore_name.jks -keysize 2048

You’ll be asked to enter and confirm a password. The password and the alias name for the private key will be required later in the process as well. Be sure to remember them else you will need to redo the entire process.

2. Complete the Form Information Fields

Next, you’ll be prompted to enter further details like first and last name, city, state, etc., similar to the information requested while filling out a CSR for an SSL certificate.

Enter keystore password:
Re-enter new password:
What is your first and last name?
 [Unknown]: Firstname Lastname or DomainName
What is the name of your organizational unit?
 [Unknown]: DepartmentName
What is the name of your organization?
 [Unknown]: CompanyName or Firstname Lastname
What is the name of your City or Locality?
 [Unknown]: YourCity
What is the name of your State or Province?
 [Unknown]: YourState or YourProvince
What is the two-letter country code for this unit?
 [Unknown]: YourCountryCode
Is CN= DomainName or Firstname Lastname, OU=YourDepartment, O=YourCompanyName or Firstname Lastname, L=YourCity, ST=YourState, C=US correct?
 [no]: yes
Enter key password for <server>
 (RETURN if same as keystore password):

3. Confirm Your Submission to Generate Your KeyStore File

Once the details have been filled in, you can confirm or reject your submission by typing Yes or No. After all the details are entered correctly, a Java KeyStore file (keystore_name.jks from the above example) will be created.

Generating a CSR

Follow the instructions below to generate a certificate signing request (CSR) for your java code signing certificate.

1. Generate Your CSR Using the Command Line Interface

Once the KeyStore is created, you can generate your (CSR) using the command below:

keytool -certreq -keyalg RSA -alias alias_name -file your_csr_file.csr -keystore keystore_name.jks

Consider creating a backup of your KeyStore as a safeguard against any installation issues you might run into while importing the certificate into the original file. The above command will create a private key (.jks file) and a CSR (.csr file).

2. Complete the Required Field

While purchasing your Java code signing certificate, open the “.csr” file created in the previous step with a text editor (Notepad or Vi) and simply copy and paste the contents of the file into the relevant field in the order form.

Installing the Java Code Signing Certificate on Your Server

Once the CSR request is submitted, the certificate authority (CA) will validate and issue your Java code signing certificate and share it via email. The file should have a “.p7b” extension. If it has a different extension, copy the contents of the cert file, including the headers, without any additional white spaces, line breaks, etc. Use a text editor to paste the contents and save the file with a “.p7b” extension. Alternatively, you can make use of the OpenSSL library to convert your certificate file to the required format. The steps given below describe the process of installing the Java code signing certificate onto your server.

1. Install Your Java Code Signing Certificate

To install the certificate on the server, execute the following command:

keytool -import -trustcacerts -alias alias_name -file CertFile.p7b -keystore keystore_name.jks

Note: You will be required to enter the password for theKkeyStore. If you’re asked to trust the certificate, type Y or Yes as prompted.

2. Use Your Code Signing Certificate to Sign Your Java Code

If the installation is successful, you will receive a message saying, “Certificate reply was installed in KeyStore.”

Once your code signing certificate is installed and configured into your KeyStore, you’ll be able to sign your Java code.