Here are the steps to get a free SSL certificate for Tomcat in Windows:

  1. Download and install OpenSSL on your Windows machine. You can download OpenSSL from the official website: https://www.openssl.org/.

  2. Open the OpenSSL command prompt by going to Start -> OpenSSL -> OpenSSL Command Prompt.

  3. In the OpenSSL command prompt, enter the following command to create a private key file:

    openssl genrsa -out private.key 2048

    This command will create a private key file named private.key with a key size of 2048 bits.

  4. Next, enter the following command to create a certificate signing request (CSR): 
    openssl req -new -key private.key -out csr.txt

    This command will create a CSR file named csr.txt.

  5. Open the csr.txt file in a text editor and copy the contents of the file.

  6. Go to a free SSL certificate provider website, such as https://ssl.comodo.com/free-ssl-certificate.php, and follow the instructions to generate a free SSL certificate. When prompted, paste the contents of the csr.txt file into the appropriate field.

  7. After you receive the SSL certificate from the provider, save it to a file named server.crt.

  8. Copy the private.key and server.crt files to the Tomcat conf directory (e.g., C:\Program Files\Apache Software Foundation\Tomcat 9.0\conf).

  9. Open the server.xml file in the Tomcat conf directory and add the following lines inside the <Connector> element:

  10. Save the server.xml file and restart the Tomcat server.

  11. Open a web browser and go to https://localhost:8443. You should now see the Tomcat default page served over HTTPS.

That's it! You now have a free SSL certificate installed on your Tomcat server.