public byte [] before() {
            if (this.sharedKey == null) {
                this.sharedKey = new byte[sharedKeyLength];
                crypto_box_beforenm(this.sharedKey, this.theirPublicKey, this.mySecretKey);
            }

            return this.sharedKey;
        }
public byte [ ] before ( ) { if ( this . sharedKey == null ) { this . sharedKey = new byte [ sharedKeyLength ] ; crypto_box_beforenm ( this . sharedKey , this . theirPublicKey , this . mySecretKey ) ; } return this . sharedKey ; }
/*
@description
Returns a precomputed shared key
which can be used in nacl.box.after and nacl.box.open.after.