KSI Java SDK

Guardtime's KSI Blockchain is an industrial scale blockchain platform that cryptographically ensures data integrity and proves time of existence. The KSI signatures, based on hash chains, link data to this global calendar blockchain. The checkpoints of the blockchain, published in newspapers and electronic media, enable long term integrity of any digital asset without the need to trust any system. There are many applications for KSI, a classical example is signing of any type of logs - system logs, financial transactions, call records, etc. For more, see https://guardtime.com.

The KSI Java SDK is a software development kit for developers who want to integrate KSI with their Java based applications and systems. It provides an API for all KSI functionality, including the core functions - signing of data, extending and verifying the signatures.

Installation

The latest stable binary releases are available at http://search.maven.org. Just include the dependencies in your pom.xml:

<dependency>
    <groupId>com.guardtime</groupId>
    <artifactId>ksi-api</artifactId>
    <version>4.x.x</version>
</dependency>

<dependency>
    <groupId>com.guardtime</groupId>
    <artifactId>ksi-service-client-simple-http</artifactId>
    <version>4.x.x</version>
</dependency>

If you need the latest version, download the source and build using Maven.

Proxy Configuration

KSI Java SDK can be configured to use proxy either via ApacheHttpClient or SimpleHttpClient, see details in the API reference.

The example of the use of proxy with KSI Java SDK using SimpleHttpClient would be:

HttpClientSettings.HTTPConnectionParameters proxyParam =
              new HttpClientSettings.HTTPConnectionParameters();
proxyParam.setProxyUrl(new URL("<proxyUrl>"));
proxyParam.setProxyUser("<proxyUsername>");
proxyParam.setProxyPassword("<proxyKey");

HttpClientSettings settings =
    new HttpClientSettings(aggregatorUrl,
                          extenderUrl,
                          publicationsFileUrl,
                          credentials);
settings.setParameters(proxyParam);
SimpleHttpClient simpleHttpClient = new SimpleHttpClient(settings);

Usage

In order to get trial access to the KSI platform, go to https://guardtime.com/blockchain-developers.

A simple example how to obtain a signature:

CredentialsAwareHttpSettings settings = new CredentialsAwareHttpSettings("signing-service-url", KSIServiceCredentials);
SimpleHttpSigningClient signingClient = new SimpleHttpSigningClient(settings);

Signer signer = new SignerBuilder().setSigningService(new KSISigningClientServiceAdapter(signingClient)).build();

KSISignature signature = signer.sign(new File("file.txt"));

The API full reference is available at http://guardtime.github.io/ksi-java-sdk/. Sample codes for signing, extending and verification are available at https://github.com/guardtime/ksi-sdk-samples.

Compiling the Code

To compile the code you need JDK 8 (or later) and Maven. The project can be built via the command line by executing the following maven command:

mvn clean install

This command tells Maven to build all the modules, and to install it in the local repository. This command also runs all integration and unit tests. In order to run the integration tests successfully you need to have access to KSI service, the simplest is to request a trial account here https://guardtime.com/blockchain-developers. Add the KSI configuration to the file "ksi-api/src/test/resources/integrationtest.properties" (see file "ksi-api/src/test/resources/integrationtest.properties.sample" for more information).

You can also skip the integration tests by executing the following command:

mvn clean install -DskipITs

You can skip unit and integration tests by executing the following command:

mvn clean install -DskipTests -DskipITs

Dependencies

See Maven pom.xml files or use the following Maven command

mvn dependency:tree

Compatibility

Java 8 or newer.

Contributing

See CONTRIBUTING.md file.

License

See LICENSE file.