public DecryptingInputStream()

in encryption/src/main/java/org/apache/solr/encryption/crypto/DecryptingInputStream.java [94:128]

• 34 lines of code
• 5 McCabe index (conditional complexity)

  public DecryptingInputStream(InputStream inputStream,
                               long position,
                               byte[] iv,
                               byte[] key,
                               AesCtrEncrypterFactory factory,
                               int bufferCapacity)
    throws IOException {
    if (position < 0) {
      throw new IllegalArgumentException("Invalid position " + position);
    }
    this.inputStream = inputStream;
    assert bufferCapacity % AES_BLOCK_SIZE == 0;
    inBuffer = new byte[bufferCapacity];
    outBuffer = new byte[bufferCapacity + AES_BLOCK_SIZE];
    oneByteBuf = new byte[1];
    long counter;
    if (position == 0) {
      // Read the IV at the beginning of the input stream.
      iv = new byte[IV_LENGTH];
      int n = inputStream.read(iv, 0, iv.length);
      if (n != iv.length) {
        throw new IOException("Missing IV");
      }
      counter = 0;
    } else if (iv == null) {
      throw new IllegalArgumentException("IV must be provided when position is not zero");
    } else {
      counter = position / AES_BLOCK_SIZE;
      padding = (int) (position & AES_BLOCK_SIZE_MOD_MASK);
      inPos = padding;
    }
    this.iv = iv;
    encrypter = factory.create(key, iv);
    encrypter.init(counter);
  }