Hadoop Crypto

Hadoop Crypto is a library for per-file client-side encryption in Hadoop FileSystems such as HDFS or S3. It provides wrappers for the Hadoop FileSystem API that transparently encrypt and decrypt the underlying streams. The encryption algorithm uses Key Encapsulation: each file is encrypted with a unique symmetric key, which is itself secured with a public/private key pair and stored alongside the file.

Architecture

The EncryptedFileSystem wraps any FileSystem implementation and encrypts the streams returned by open and close. These streams are encrypted/decrypted by a unique per-file symmetric key which is then passed to the KeyStorageStrategy which stores the key for future access. The provided storage strategy implementation encrypts the symmetric key using a public/private key pair and then stores the encrypted key on the FileSystem with the encrypted file.

Example

Source for examples can be found here

Initialization

KeyPair pair = KeyPairs.generateKeyPair(); // Long lived KeyPair that must be saved
FileSystem fs = FileSystem.get(new URI("file:///"), new Configuration());
KeyStorageStrategy keyStore = new FileKeyStorageStrategy(fs, pair);
FileSystem efs = new EncryptedFileSystem(fs, keyStore);

Writing data using EFS

// Init data and local path to write to
byte[] data = "test".getBytes(StandardCharsets.UTF_8);
byte[] readData = new byte[data.length];
Path path = new Path(folder.newFile().getAbsolutePath());

// Write data out to the encrypted stream
OutputStream eos = efs.create(path);
eos.write(data);
eos.close();

// Reading through the decrypted stream produces the original bytes
InputStream ein = efs.open(path);
IOUtils.readFully(ein, readData);
assertThat(data, is(readData));

// Reading through the raw stream produces the encrypted bytes
InputStream in = fs.open(path);
IOUtils.readFully(in, readData);
assertThat(data, is(not(readData)));

// Wrapped symmetric key is stored next to the encrypted file
assertTrue(fs.exists(new Path(path + FileKeyStorageStrategy.EXTENSION)));

Hadoop Configuration Properties

fs.cipher - The cipher used to wrap the underlying streams. Default: AES/CTR/NoPadding

License

This repository is made available under the Apache 2.0 License.