Add new payload converter sample using jackson-json-crypto

[tsurdilo]

Add new sample for encrypting/decrypting json payloads
that uses jackson-json-crypto module

[mapoulos]

One thing I noticed: I had very bad performance with the default settings (256 key length). I think it was running the key generation for each decrypt and temporal was complaining about the thread not yielding within a second. Decreasing this down to 128 helped.

[mapoulos]

        // overwrite the default mapper to support Java Optional and Encrypting of Sensitive fields
        var objectMapper = new ObjectMapper();
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        objectMapper.registerModule(new JavaTimeModule());
        objectMapper.registerModule(new Jdk8Module());
        objectMapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

        // It seems like the key derivation at 256 takes a long time, so we reduce it here to 128.
        var passwordCryptoContext = new PasswordCryptoContext(this.encryptionPassword, this.encryptionPassword, "AES/CBC/PKCS5Padding", "PBKDF2WithHmacSHA512", 5000, 128, "AES");
        var encryptionService = new EncryptionService(objectMapper, passwordCryptoContext);
        objectMapper.registerModule(new CryptoModule().addEncryptionService(encryptionService));
        var jacksonJsonPayloadConverter = new JacksonJsonPayloadConverter(objectMapper);

        // override the jackson converter
        var defaultDataConverter = DefaultDataConverter.newDefaultInstance().withPayloadConverterOverrides(jacksonJsonPayloadConverter);

        // instantiate the workflow service, which connects to the temporal cluster
        var serviceOptions = WorkflowServiceStubsOptions.newBuilder()
                .setTarget(target)
                .setEnableHttps(useSSL)
                .build();
        workflowService = WorkflowServiceStubs.newInstance(serviceOptions);

        // instatiate the workflow client, which specifies the temporal namespace
        // and the data converter
        var clientOptions = WorkflowClientOptions
            .newBuilder()
            .setNamespace(namespace)
            .setDataConverter(defaultDataConverter)
            .build();
        workflowClient = WorkflowClient.newInstance(workflowService, clientOptions);

[tsurdilo]

@mapoulos thanks for the info!

[tsurdilo]

@mapoulos will have to use jackson-json-crypto:1.1.0
cause our samples are built with java 1.8 (jackson-json-crypto after 2.x seems to require java 11) just fyi