/**
* @param uncompressedBytesWithHeader
* @param blockType
* @param headerBytes
* @throws IOException
*/
protected void compressAfterEncoding(
byte[] uncompressedBytesWithHeader, BlockType blockType, byte[] headerBytes)
throws IOException {
this.uncompressedBytesWithHeader = uncompressedBytesWithHeader;
Encryption.Context cryptoContext = fileContext.getEncryptionContext();
if (cryptoContext != Encryption.Context.NONE) {
// Encrypted block format:
// +--------------------------+
// | byte iv length |
// +--------------------------+
// | iv data ... |
// +--------------------------+
// | encrypted block data ... |
// +--------------------------+
cryptoByteStream.reset();
// Write the block header (plaintext)
cryptoByteStream.write(headerBytes);
InputStream in;
int plaintextLength;
// Run any compression before encryption
if (fileContext.getCompression() != Compression.Algorithm.NONE) {
compressedByteStream.reset();
compressionStream.resetState();
compressionStream.write(
uncompressedBytesWithHeader,
headerBytes.length,
uncompressedBytesWithHeader.length - headerBytes.length);
compressionStream.flush();
compressionStream.finish();
byte[] plaintext = compressedByteStream.toByteArray();
plaintextLength = plaintext.length;
in = new ByteArrayInputStream(plaintext);
} else {
plaintextLength = uncompressedBytesWithHeader.length - headerBytes.length;
in =
new ByteArrayInputStream(
uncompressedBytesWithHeader, headerBytes.length, plaintextLength);
}
if (plaintextLength > 0) {
// Set up the cipher
Cipher cipher = cryptoContext.getCipher();
Encryptor encryptor = cipher.getEncryptor();
encryptor.setKey(cryptoContext.getKey());
// Set up the IV
int ivLength = iv.length;
Preconditions.checkState(ivLength <= Byte.MAX_VALUE, "IV length out of range");
cryptoByteStream.write(ivLength);
if (ivLength > 0) {
encryptor.setIv(iv);
cryptoByteStream.write(iv);
}
// Encrypt the data
Encryption.encrypt(cryptoByteStream, in, encryptor);
onDiskBytesWithHeader = cryptoByteStream.toByteArray();
// Increment the IV given the final block size
Encryption.incrementIv(iv, 1 + (onDiskBytesWithHeader.length / encryptor.getBlockSize()));
} else {
cryptoByteStream.write(0);
onDiskBytesWithHeader = cryptoByteStream.toByteArray();
}
} else {
if (this.fileContext.getCompression() != NONE) {
compressedByteStream.reset();
compressedByteStream.write(headerBytes);
compressionStream.resetState();
compressionStream.write(
uncompressedBytesWithHeader,
headerBytes.length,
uncompressedBytesWithHeader.length - headerBytes.length);
compressionStream.flush();
compressionStream.finish();
onDiskBytesWithHeader = compressedByteStream.toByteArray();
} else {
onDiskBytesWithHeader = uncompressedBytesWithHeader;
}
}
this.blockType = blockType;
}
protected void incrementIv(int v) {
Encryption.incrementIv(iv.get(), 1 + (v / encryptor.getBlockSize()));
}