Example usage for java.nio ByteBuffer putLong

Introduction

In this page you can find the example usage for java.nio ByteBuffer putLong.

Prototype

public abstract ByteBuffer putLong(int index, long value);

Source Link

Document

Writes the given long to the specified index of this buffer.

Usage

From source file:org.cryptomator.crypto.aes256.Aes256Cryptor.java

@Override
public Long encryptFile(InputStream plaintextFile, SeekableByteChannel encryptedFile) throws IOException {
    // truncate file
    encryptedFile.truncate(0);/*ww w. ja v  a2  s  .  co m*/

    // use an IV, whose last 8 bytes store a long used in counter mode and write initial value to file.
    final ByteBuffer countingIv = ByteBuffer.wrap(randomData(AES_BLOCK_LENGTH));
    countingIv.putLong(AES_BLOCK_LENGTH - Long.BYTES, 0l);
    countingIv.position(0);
    encryptedFile.write(countingIv);

    // init crypto stuff:
    final Mac mac = this.hmacSha256(hMacMasterKey);
    final Cipher cipher = this.aesCtrCipher(primaryMasterKey, countingIv.array(), Cipher.ENCRYPT_MODE);

    // init mac buffer and skip 32 bytes
    final ByteBuffer macBuffer = ByteBuffer.allocate(mac.getMacLength());
    encryptedFile.write(macBuffer);

    // init filesize buffer and skip 16 bytes
    final ByteBuffer encryptedFileSizeBuffer = ByteBuffer.allocate(AES_BLOCK_LENGTH);
    encryptedFile.write(encryptedFileSizeBuffer);

    // write content:
    final OutputStream out = new SeekableByteChannelOutputStream(encryptedFile);
    final OutputStream macOut = new MacOutputStream(out, mac);
    final OutputStream cipheredOut = new CipherOutputStream(macOut, cipher);
    final OutputStream blockSizeBufferedOut = new BufferedOutputStream(cipheredOut, AES_BLOCK_LENGTH);
    final Long plaintextSize = IOUtils.copyLarge(plaintextFile, blockSizeBufferedOut);

    // ensure total byte count is a multiple of the block size, in CTR mode:
    final int remainderToFillLastBlock = AES_BLOCK_LENGTH - (int) (plaintextSize % AES_BLOCK_LENGTH);
    blockSizeBufferedOut.write(new byte[remainderToFillLastBlock]);

    // append a few blocks of fake data:
    final int numberOfPlaintextBlocks = (int) Math.ceil(plaintextSize / AES_BLOCK_LENGTH);
    final int upToTenPercentFakeBlocks = (int) Math.ceil(Math.random() * 0.1 * numberOfPlaintextBlocks);
    final byte[] emptyBytes = new byte[AES_BLOCK_LENGTH];
    for (int i = 0; i < upToTenPercentFakeBlocks; i += AES_BLOCK_LENGTH) {
        blockSizeBufferedOut.write(emptyBytes);
    }
    blockSizeBufferedOut.flush();

    // write MAC of total ciphertext:
    macBuffer.position(0);
    macBuffer.put(mac.doFinal());
    macBuffer.position(0);
    encryptedFile.position(16); // right behind the IV
    encryptedFile.write(macBuffer); // 256 bit MAC

    // encrypt and write plaintextSize
    try {
        final ByteBuffer fileSizeBuffer = ByteBuffer.allocate(Long.BYTES);
        fileSizeBuffer.putLong(plaintextSize);
        final Cipher sizeCipher = aesEcbCipher(primaryMasterKey, Cipher.ENCRYPT_MODE);
        final byte[] encryptedFileSize = sizeCipher.doFinal(fileSizeBuffer.array());
        encryptedFileSizeBuffer.position(0);
        encryptedFileSizeBuffer.put(encryptedFileSize);
        encryptedFileSizeBuffer.position(0);
        encryptedFile.position(48); // right behind the IV and MAC
        encryptedFile.write(encryptedFileSizeBuffer);
    } catch (IllegalBlockSizeException | BadPaddingException e) {
        throw new IllegalStateException(
                "Block size must be valid, as padding is requested. BadPaddingException not possible in encrypt mode.",
                e);
    }

    return plaintextSize;
}

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From source file:org.apache.hadoop.crypto.CryptoStreamsTestBase.java

private void setCounterBaseForIV(byte[] iv, long counterBase) {
    ByteBuffer buf = ByteBuffer.wrap(iv);
    buf.order(ByteOrder.BIG_ENDIAN);
    buf.putLong(iv.length - 8, counterBase);
}

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From source file:org.cryptomator.crypto.aes256.Aes256Cryptor.java

@Override
public Long decryptRange(SeekableByteChannel encryptedFile, OutputStream plaintextFile, long pos, long length)
        throws IOException {
    // read iv:/*from w w  w .ja va  2 s .  c  o  m*/
    encryptedFile.position(0);
    final ByteBuffer countingIv = ByteBuffer.allocate(AES_BLOCK_LENGTH);
    final int numIvBytesRead = encryptedFile.read(countingIv);

    // check validity of header:
    if (numIvBytesRead != AES_BLOCK_LENGTH) {
        throw new IOException("Failed to read file header.");
    }

    // seek relevant position and update iv:
    long firstRelevantBlock = pos / AES_BLOCK_LENGTH; // cut of fraction!
    long beginOfFirstRelevantBlock = firstRelevantBlock * AES_BLOCK_LENGTH;
    long offsetInsideFirstRelevantBlock = pos - beginOfFirstRelevantBlock;
    countingIv.putLong(AES_BLOCK_LENGTH - Long.BYTES, firstRelevantBlock);

    // fast forward stream:
    encryptedFile.position(64 + beginOfFirstRelevantBlock);

    // generate cipher:
    final Cipher cipher = this.aesCtrCipher(primaryMasterKey, countingIv.array(), Cipher.DECRYPT_MODE);

    // read content
    final InputStream in = new SeekableByteChannelInputStream(encryptedFile);
    final InputStream cipheredIn = new CipherInputStream(in, cipher);
    return IOUtils.copyLarge(cipheredIn, plaintextFile, offsetInsideFirstRelevantBlock, length);
}

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