Through this I am sharing the most simple scenario to follow in using Java keytool for the requirements of Apache Wookie projects digital signature implementation. Anyway if you are looking to know how to generate a key pair or import a certificate to a Keystore using keytool, still this may be helpful. Refer this segment of Java SE documentation to know in-depth details.
You needs a configuration of Java in your computer to use keytool and that is enough :).
Generating Key Pairs
Use following command in command prompt to generate a keypair with a self-signed certificate
keytool -genkey -alias wookie -keyalg RSA -keystore wookieKeystore.jks -keysize 4096
After -alias give the alias to be used for keys
-keylag give the algorithm to be used in key generation
-keystore give the name of the keystore with type .jks (You can give a path here to store the keystore in a desired place)
-keysize give the length for the generating key in bits
This will look something as follows,
That's all and you are having a key pair now. :)
In Aspects of Wookie, now you can sign Widgets using this keystore. But in order to get your widgets verified and deployed in Wookie server you needs to get your public key trusted by server directly or via a third party.
Generating .cer File
To insert a public key certificate into a trusted keystore it needs to be exported as a .cer file. (There are several other options to use too.)
keytool -v -export -file keystore1.cer -keystore wookieKeystore.jks -alias wookie
Importing Public Key Certificates to a Trusted Keystore
To import a trusted certificate to a trusted keystore following command can be used.
keytool -import -alias keystore1 -file keystore1.cer -keystore wookieKeystore.jks
This command simply says to import the public key certificate of key having alias 'keystore1' which is in the file keystore1.cer to the keystore 'wookieKeystore.jks'.
Now any signature generated using the private key of keystore1 aliased key pair, can be properly validated using wookieKeystore.jks.