Examples with IonReader com.amazon.ion.IonReader used on opensource projects

Example 1 with IonReader

use of com.amazon.ion.IonReader in project amazon-qldb-dmv-sample-java by aws-samples.

the class GetRevision method verifyRegistration.

/**
 * Verify each version of the registration for the given VIN.
 *
 * @param driver
 *              A QLDB driver.
 * @param ledgerName
 *              The ledger to get digest from.
 * @param vin
 *              VIN to query the revision history of a specific registration with.
 * @throws Exception if failed to verify digests.
 * @throws AssertionError if document revision verification failed.
 */
public static void verifyRegistration(final QldbDriver driver, final String ledgerName, final String vin) throws Exception {
    log.info(String.format("Let's verify the registration with VIN=%s, in ledger=%s.", vin, ledgerName));
    try {
        log.info("First, let's get a digest.");
        GetDigestResult digestResult = GetDigest.getDigest(ledgerName);
        ValueHolder digestTipAddress = digestResult.getDigestTipAddress();
        byte[] digestBytes = Verifier.convertByteBufferToByteArray(digestResult.getDigest());
        log.info("Got a ledger digest. Digest end address={}, digest={}.", QldbStringUtils.toUnredactedString(digestTipAddress), Verifier.toBase64(digestBytes));
        log.info(String.format("Next, let's query the registration with VIN=%s. " + "Then we can verify each version of the registration.", vin));
        List<IonStruct> documentsWithMetadataList = new ArrayList<>();
        driver.execute(txn -> {
            documentsWithMetadataList.addAll(queryRegistrationsByVin(txn, vin));
        });
        log.info("Registrations queried successfully!");
        log.info(String.format("Found %s revisions of the registration with VIN=%s.", documentsWithMetadataList.size(), vin));
        for (IonStruct ionStruct : documentsWithMetadataList) {
            QldbRevision document = QldbRevision.fromIon(ionStruct);
            log.info(String.format("Let's verify the document: %s", document));
            log.info("Let's get a proof for the document.");
            GetRevisionResult proofResult = getRevision(ledgerName, document.getMetadata().getId(), digestTipAddress, document.getBlockAddress());
            final IonValue proof = Constants.MAPPER.writeValueAsIonValue(proofResult.getProof());
            final IonReader reader = IonReaderBuilder.standard().build(proof);
            reader.next();
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            IonWriter writer = SYSTEM.newBinaryWriter(baos);
            writer.writeValue(reader);
            writer.close();
            baos.flush();
            baos.close();
            byte[] byteProof = baos.toByteArray();
            log.info(String.format("Got back a proof: %s", Verifier.toBase64(byteProof)));
            boolean verified = Verifier.verify(document.getHash(), digestBytes, proofResult.getProof().getIonText());
            if (!verified) {
                throw new AssertionError("Document revision is not verified!");
            } else {
                log.info("Success! The document is verified");
            }
            byte[] alteredDigest = Verifier.flipRandomBit(digestBytes);
            log.info(String.format("Flipping one bit in the digest and assert that the document is NOT verified. " + "The altered digest is: %s", Verifier.toBase64(alteredDigest)));
            verified = Verifier.verify(document.getHash(), alteredDigest, proofResult.getProof().getIonText());
            if (verified) {
                throw new AssertionError("Expected document to not be verified against altered digest.");
            } else {
                log.info("Success! As expected flipping a bit in the digest causes verification to fail.");
            }
            byte[] alteredDocumentHash = Verifier.flipRandomBit(document.getHash());
            log.info(String.format("Flipping one bit in the document's hash and assert that it is NOT verified. " + "The altered document hash is: %s.", Verifier.toBase64(alteredDocumentHash)));
            verified = Verifier.verify(alteredDocumentHash, digestBytes, proofResult.getProof().getIonText());
            if (verified) {
                throw new AssertionError("Expected altered document hash to not be verified against digest.");
            } else {
                log.info("Success! As expected flipping a bit in the document hash causes verification to fail.");
            }
        }
    } catch (Exception e) {
        log.error("Failed to verify digests.", e);
        throw e;
    }
    log.info(String.format("Finished verifying the registration with VIN=%s in ledger=%s.", vin, ledgerName));
}

Example 2 with IonReader

use of com.amazon.ion.IonReader in project amazon-qldb-dmv-sample-java by aws-samples.

the class JournalS3ExportReader method getDataFileKeysFromManifest.

/**
 * Given the S3Object to the completed manifest file, return the keys
 * which are part of this export request.
 *
 * @param s3Object
 *              A {@link S3Object}.
 * @return a list of data file keys containing the chunk of {@link JournalBlock}.
 */
private static List<String> getDataFileKeysFromManifest(final S3Object s3Object) {
    IonReader ionReader = IonReaderBuilder.standard().build(s3Object.getObjectContent());
    // Read the data
    ionReader.next();
    List<String> keys = new ArrayList<>();
    IonStruct ionStruct = (IonStruct) SYSTEM.newValue(ionReader);
    IonList ionKeysList = (IonList) ionStruct.get("keys");
    ionKeysList.forEach(key -> keys.add(((IonString) key).stringValue()));
    return keys;
}

Example 3 with IonReader

use of com.amazon.ion.IonReader in project amazon-qldb-dmv-sample-java by aws-samples.

the class TransferVehicleOwnership method findPrimaryOwnerForVehicle.

/**
 * Find the primary owner for the given VIN.
 *
 * @param txn
 *              The {@link TransactionExecutor} for lambda execute.
 * @param vin
 *              Unique VIN for a vehicle.
 * @return a {@link Person} object.
 * @throws IllegalStateException if failed to convert parameter into {@link IonValue}.
 */
public static Person findPrimaryOwnerForVehicle(final TransactionExecutor txn, final String vin) {
    try {
        log.info("Finding primary owner for vehicle with Vin: {}...", vin);
        final String query = "SELECT Owners.PrimaryOwner.PersonId FROM VehicleRegistration AS v WHERE v.VIN = ?";
        final List<IonValue> parameters = Collections.singletonList(Constants.MAPPER.writeValueAsIonValue(vin));
        Result result = txn.execute(query, parameters);
        final List<IonStruct> documents = ScanTable.toIonStructs(result);
        ScanTable.printDocuments(documents);
        if (documents.isEmpty()) {
            throw new IllegalStateException("Unable to find registrations with VIN: " + vin);
        }
        final IonReader reader = IonReaderBuilder.standard().build(documents.get(0));
        final String personId = Constants.MAPPER.readValue(reader, LinkedHashMap.class).get("PersonId").toString();
        return findPersonFromDocumentId(txn, personId);
    } catch (IOException ioe) {
        throw new IllegalStateException(ioe);
    }
}

Example 4 with IonReader

use of com.amazon.ion.IonReader in project amazon-qldb-dmv-sample-java by aws-samples.

the class Proof method fromBlob.

/**
 * Decodes a {@link Proof} from an ion text String. This ion text is returned in
 * a {@link GetRevisionResult#getProof()}
 *
 * @param ionText
 *              The ion text representing a {@link Proof} object.
 * @return {@link JournalBlock} parsed from the ion text.
 * @throws IllegalStateException if failed to parse the {@link Proof} object from the given ion text.
 */
public static Proof fromBlob(final String ionText) {
    try {
        IonReader reader = SYSTEM.newReader(ionText);
        List<byte[]> list = new ArrayList<>();
        reader.next();
        reader.stepIn();
        while (reader.next() != null) {
            list.add(reader.newBytes());
        }
        return new Proof(list);
    } catch (Exception e) {
        throw new IllegalStateException("Failed to parse a Proof from byte array");
    }
}

Example 5 with IonReader

use of com.amazon.ion.IonReader in project amazon-qldb-dmv-sample-java by aws-samples.

the class QldbIonUtils method hashIonValue.

/**
 * Builds a hash value from the given {@link IonValue}.
 *
 * @param ionValue
 *              The {@link IonValue} to hash.
 * @return a byte array representing the hash value.
 */
public static byte[] hashIonValue(final IonValue ionValue) {
    IonReader reader = Constants.SYSTEM.newReader(ionValue);
    IonHashReader hashReader = IonHashReaderBuilder.standard().withHasherProvider(ionHasherProvider).withReader(reader).build();
    while (hashReader.next() != null) {
    }
    return hashReader.digest();
}