public static InitializationVector deriveIv()

in c3r-sdk-core/src/main/java/com/amazonaws/c3r/internal/InitializationVector.java [50:75]

• 26 lines of code
• 6 McCabe index (conditional complexity)

    public static InitializationVector deriveIv(final String label, final Nonce nonce) {
        if (label == null || label.isBlank()) {
            throw new C3rIllegalArgumentException("A column label must be provided when generating an IV, but was null or empty.");
        }
        if (nonce == null) {
            throw new C3rIllegalArgumentException("A nonce must be provided when generating an IV, but was null.");
        }
        final byte[] labelBytes = label.getBytes(StandardCharsets.UTF_8);
        final byte[] nonceBytes = nonce.getBytes();
        final byte[] buffer = ByteBuffer.allocate(labelBytes.length + nonceBytes.length)
                .put(labelBytes)
                .put(nonceBytes)
                .array();
        final MessageDigest messageDigest;
        try {
            messageDigest = MessageDigest.getInstance(KeyUtil.HASH_ALG);
        } catch (NoSuchAlgorithmException e) {
            throw new C3rRuntimeException("Requested algorithm `" + KeyUtil.HASH_ALG + "` is not available!", e);
        }
        final byte[] hash = messageDigest.digest(buffer);
        final byte[] iv = new byte[InitializationVector.IV_BYTE_LENGTH];
        if (hash != null) {
            ByteBuffer.wrap(hash).get(iv);
        }
        return new InitializationVector(iv);
    }