Examples with BlockAddress software.amazon.qldb.tutorial.qldb.BlockAddress used on opensource projects

Example 1 with BlockAddress

use of software.amazon.qldb.tutorial.qldb.BlockAddress in project amazon-qldb-dmv-sample-java by aws-samples.

the class GetBlock method main.

public static void main(String[] args) {
    try {
        List<IonStruct> results = ConnectToLedger.getDriver().execute(txn -> {
            final String vin = SampleData.VEHICLES.get(1).getVin();
            return GetRevision.queryRegistrationsByVin(txn, vin);
        });
        BlockAddress blockAddress = Constants.MAPPER.readValue(results.get(0), QldbRevision.class).getBlockAddress();
        verifyBlock(Constants.LEDGER_NAME, blockAddress);
    } catch (Exception e) {
        log.error("Unable to query vehicle registration by Vin.", e);
    }
}

Example 2 with BlockAddress

use of software.amazon.qldb.tutorial.qldb.BlockAddress in project amazon-qldb-dmv-sample-java by aws-samples.

the class GetBlock method verifyBlock.

public static void verifyBlock(String ledgerName, BlockAddress blockAddress) throws Exception {
    log.info("Lets verify blocks for ledger with name={}.", ledgerName);
    try {
        log.info("First, let's get a digest");
        GetDigestResult digestResult = GetDigest.getDigest(ledgerName);
        BlockAddress tipBlockAddress = Constants.MAPPER.readValue(digestResult.getDigestTipAddress().getIonText(), BlockAddress.class);
        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));
        GetBlockResult getBlockResult = getBlockWithProof(ledgerName, blockAddress, tipBlockAddress);
        JournalBlock block = Constants.MAPPER.readValue(getBlockResult.getBlock().getIonText(), JournalBlock.class);
        boolean verified = Verifier.verify(block.getBlockHash(), digestBytes, getBlockResult.getProof().getIonText());
        if (!verified) {
            throw new AssertionError("Block is not verified!");
        } else {
            log.info("Success! The block is verified.");
        }
        byte[] alteredDigest = Verifier.flipRandomBit(digestBytes);
        log.info("Let's try flipping one bit in the digest and assert that the block is NOT verified. " + "The altered digest is: {}.", Verifier.toBase64(alteredDigest));
        verified = Verifier.verify(block.getBlockHash(), alteredDigest, getBlockResult.getProof().getIonText());
        if (verified) {
            throw new AssertionError("Expected block to not be verified against altered digest.");
        } else {
            log.info("Success! As expected flipping a bit in the digest causes verification to fail.");
        }
        byte[] alteredBlockHash = Verifier.flipRandomBit(block.getBlockHash());
        log.info("Let's try flipping one bit in the block's hash and assert that the block is NOT " + "verified. The altered block hash is: {}.", Verifier.toBase64(alteredBlockHash));
        verified = Verifier.verify(alteredBlockHash, digestBytes, getBlockResult.getProof().getIonText());
        if (verified) {
            throw new AssertionError("Expected altered block hash to not be verified against digest.");
        } else {
            log.info("Success! As expected flipping a bit in the block hash causes verification to fail.");
        }
    } catch (Exception e) {
        log.error("Failed to verify blocks in the ledger with name={}.", ledgerName, e);
        throw e;
    }
}