Guardtime signature container API

Create new container, add and sign files

Container is based on ZIP format and contains files with following structure:

• datafile.xxx
• META-INF/manifestX.tlv
• META-INF/signatureX.ksi

Initialization

API represented in ConteinerServiceAPI interface. Current implementation is in class ZipContainerServiceImpl.First of all you need to initialize container with method

initialize(HttpClientSettings httpClientSettings, File outputFile)

First parameter httpClientSetting should contain Guardtime service information and credentials. Second parameter outputFile is a File where container will be stored after creation.

Adding new signatures

To add new data file and sign it, you should use method

addFileAndSign(HashAlgorithm fileHashingAlgorithm, InputStream inputStream, String filename)

First parameter fileHashingAlgorithm define which hashing algorithm should be used. Second parameter inputStream is an input stream of new file. And one more parameter filename define what filename should be assigned to data file in container.

Adding multiple files

To add new multiple data files into container and sign them, you should use method

addFilesAndSign(HashAlgorithm fileHashingAlgorithm, List<File> files)

Finalization

When all files added to container you should finalize process and call method

finish()

It will flush and close ZIP container's output stream.

Open existing container and add more data files

To open and modify existing container you should initialize service with method

initializeFromExisting(HttpClientSettings httpClientSettings, File inputFile)

• httpClientSettings - parameter for Guardtime service parameters and credentials
• inputFile - existing container file

While standard ZIP format API does not allow make modifications in existing ZIP files, we should write down another temporary copy of container. After all modifications old version will be replaced with new version of file.

After initialization adding new data files and signatures can be done in normal way with methods

addFileAndSign(HashAlgorithm fileHashingAlgorithm, InputStream inputStream, String filename)

or

addFilesAndSign(HashAlgorithm fileHashingAlgorithm, List<File> files)

and at the end you need to finalize process.

Open existing container and remove signature

To remove signature you need initialized service with method:

initializeFromExisting(HttpClientSettings httpClientSettings, File inputFile)

After that you can execute method

removeSignature(String signatureUri)

and at the end you need to finalize process.

Please note that removing signature mean also removing manifest file and datafile from container

Common examples

Simplest example for creating container, adding and signing datafile

     File file = new File("/tmp/datafile1.txt");
     FileInputStream fis = new FileInputStream(file);
     ContainerService containerService = new ZipContainerServiceImpl();
     containerService.initialize(httpClientSettings, new File("/tmp/container.zip"));
     containerService.addFileAndSign(HashAlgorithm.SHA2_256, fis, file.getName());
     containerService.finish();

For adding new signature to existing container

    ContainerService containerService = new ZipContainerServiceImpl();
    containerService.initializeFromExisting(httpClientSettings, existingContainer);

    File file = new File("/tmp/datafile2.txt");
    FileInputStream fis = new FileInputStream(file);
    containerService.addFileAndSign(HashAlgorithm.SHA2_256, fis, file.getName());
    containerService.finish();

Removing signature from existing container

    ContainerService containerService = new ZipContainerServiceImpl();
    containerService.initializeFromExisting(httpClientSettings, oldzip);

    final String signatureUriToRemove = "/META-INF/signature1.ksi";
    containerService.removeSignature(signatureUriToRemove);
    containerService.finish();

To execute unit test use following maven command:

mvn test -Dksi.gw.username= \
  -Dksi.gw.password= \
  -Dksi.gw.signing.uri=http://tryout.guardtime.net:8080/gt-signingservice \
  -Dksi.gw.extending.uri=http://tryout-extender.guardtime.net:8081/gt-extendingservice \
  -Dksi.gw.publications.uri=http://verify.guardtime.com/ksi-publications.bin