How to Get and Configure a Free SSL Certificate for Your Mini‑Program in Spring Boot

Step 1: Apply for an SSL Certificate

Use a free service such as https://freessl.cn/. Choose the offline generation option, which requires domain validation via a client software. Alibaba Cloud users can use one‑click generation but must provide an authorization code; this method does not support mini‑programs and works only on a PC.

Note: Install the required client software; it will automatically validate the domain. If you are learning Spring Boot, you may refer to a free tutorial at http://blog.didispace.com/spring-boot-learning-2x/.

If the validation stalls, switch to the "One‑click Apply" option and select "I am not an Alibaba Cloud user" to use software verification, which completes instantly.

Step 2: Export the Certificate

The export method varies by platform; the example below shows the process used by the author.

1. Export the certificate using the provided website tool.

The tool downloads a ZIP package containing the certificate files.

Open the IIS (not Tomcat) directory; most SSL providers now issue PFX certificates, which are easier to use than JKS certificates that may cause renewal issues.

Step 3: Configure the Code

server:
  port: 443
  ssl:
    key-store: classpath:aaaaa.pfx
    key-store-password: yourpassword
    keyStoreType: PKCS12

The password is the one you set during the certificate export step; any value works as long as it matches the exported file. The file name should also correspond to the actual certificate file.