How do you encrypt the configuration file for Tomcat data source?

There are two methods to encrypt sensitive information in the data source configuration file of Tomcat.

1. Use Tomcat’s encryption tool.
2. In the bin folder of the Tomcat installation directory, you can find a script file named digest.sh (Linux/Mac) or digest.bat (Windows).
3. To run the script, use the following command to generate the encrypted password: ./digest.sh -a [algorithm] [plaintext password] or digest.bat -a [algorithm] [plaintext password]. [Algorithm] stands for the selected encryption algorithm, such as MD5, SHA, SHA-256, etc., and [plaintext password] represents the password to be encrypted.
4. The script will generate an encrypted string, which should be copied into the password field in the data source configuration file.
5. Encrypt using a cryptographic library.
6. Encrypt passwords in Java code using encryption libraries such as Jasypt.
7. Use the encrypted password in the data source configuration file, for example: jdbc.password=ENC([encrypted password])

   Here, [encrypted password] is the password encrypted using an encryption library.

8. During Tomcat startup, provide the decryption key using Java system properties or environment variables so that Tomcat can decrypt encrypted passwords in configuration files.

It is important to ensure the security of the key and avoid storing it in plain text, regardless of the method used.