keytool

Keytool is a certificate management utility included with Java.

Create a keystore

$ keytool -genkeypair -v -keystore [path/to/file.keystore] -alias [key_name]

Change a keystore password

$ keytool -storepasswd -keystore [path/to/file.keystore]

Change a key's password inside a specific keystore

$ keytool -keypasswd -alias [key_name] -keystore [path/to/file.keystore]