Encrypt/Decrypt with public/private keys

There are built-in functions to easily encrypt/decrypt text using a single password key (using functions af.encrypt and af.decrypt). But if you need better security you might need to encrypt/decrypt using a public and a private keys.

This can be achieved using the ow.java.cipher. It enables the generation or loading of existing public and private keys and use them to encrypt/decrypt text.

To create an object instance:

ow.loadJava();
var cipher = new ow.java.cipher();

Generating public/private keys

You can generate a public and a private key with a specific key length (by default 2048 bits). You can generate for 3072, 4096, 7680 and 15360 bits (the bigger, the longer to generate):

var keys = cipher.genKeyPair(4096);

To save the private and public keys in files:

cipher.saveKey2File("key.pub", keys.publicKey, false);
cipher.saveKey2File("key.priv", keys.privateKey, true);

To load the keys from the files:

var kpPUB  = cipher.readKey4File("key.pub", false);
var kpPRIV = cipher.readKey4File("key.priv", true);

Encrypting/Decrypting text

Now that you have a pair of public and private keys you can easily encrypt/decrypt text:

var cipheredText = cipher.encrypt2Text(plainText, kpPUB);

var plainText = cipher.decrypt4Text(cipheredText, kpPRIV);

The functions with the “Text” suffix automatically convert to a Base64 text for easier transport. But there are also functions for encrypting/decrypting to/from arrays of bytes and streams.