Package org.apache.hadoop.crypto

Class CryptoCodec

java.lang.Object

org.apache.hadoop.crypto.CryptoCodec

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Configurable

Direct Known Subclasses:

JceCtrCryptoCodec, OpensslCtrCryptoCodec

@Private
@Evolving
public abstract class CryptoCodec
extends java.lang.Object
implements Configurable, java.io.Closeable

Crypto codec class, encapsulates encryptor/decryptor pair.

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
CryptoCodec()

Method Summary

Modifier and Type	Method	Description
abstract void	calculateIV(byte[] initIV, long counter, byte[] IV)	This interface is only for Counter (CTR) mode.
abstract Decryptor	createDecryptor()	Create a Decryptor.
abstract Encryptor	createEncryptor()	Create a Encryptor.
abstract void	generateSecureRandom(byte[] bytes)	Generate a number of secure, random bytes suitable for cryptographic use.
abstract CipherSuite	getCipherSuite()
static CryptoCodec	getInstance(Configuration conf)	Get crypto codec for algorithm/mode/padding in config value hadoop.security.crypto.cipher.suite
static CryptoCodec	getInstance(Configuration conf, CipherSuite cipherSuite)	Get crypto codec for specified algorithm/mode/padding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.io.Closeable

close

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Field Detail

LOG

public static org.slf4j.Logger LOG

Constructor Detail

CryptoCodec

public CryptoCodec()

Method Detail

getInstance

public static CryptoCodec getInstance(Configuration conf,
                                      CipherSuite cipherSuite)

Get crypto codec for specified algorithm/mode/padding.

Parameters:

conf - the configuration

cipherSuite - algorithm/mode/padding

Returns:

CryptoCodec the codec object. Null value will be returned if no crypto codec classes with cipher suite configured.

getInstance

public static CryptoCodec getInstance(Configuration conf)

Get crypto codec for algorithm/mode/padding in config value hadoop.security.crypto.cipher.suite

Parameters:

conf - the configuration

Returns:

CryptoCodec the codec object Null value will be returned if no crypto codec classes with cipher suite configured.

getCipherSuite

public abstract CipherSuite getCipherSuite()

Returns:

the CipherSuite for this codec.

createEncryptor

public abstract Encryptor createEncryptor()
                                   throws java.security.GeneralSecurityException

Create a Encryptor.

Returns:

Encryptor the encryptor.

Throws:

java.security.GeneralSecurityException - thrown if create encryptor error.

createDecryptor

public abstract Decryptor createDecryptor()
                                   throws java.security.GeneralSecurityException

Create a Decryptor.

Returns:

Decryptor the decryptor

Throws:

java.security.GeneralSecurityException - thrown if create decryptor error.

calculateIV

public abstract void calculateIV(byte[] initIV,
                                 long counter,
                                 byte[] IV)

This interface is only for Counter (CTR) mode. Generally the Encryptor or Decryptor calculates the IV and maintain encryption context internally. For example a Cipher will maintain its encryption context internally when we do encryption/decryption using the Cipher#update interface.

Encryption/Decryption is not always on the entire file. For example, in Hadoop, a node may only decrypt a portion of a file (i.e. a split). In these situations, the counter is derived from the file position.

The IV can be calculated by combining the initial IV and the counter with a lossless operation (concatenation, addition, or XOR). See http://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_ .28CTR.29

Parameters:

initIV - initial IV

counter - counter for input stream position

IV - the IV for input stream position

generateSecureRandom

public abstract void generateSecureRandom(byte[] bytes)

Generate a number of secure, random bytes suitable for cryptographic use. This method needs to be thread-safe.

Parameters:

bytes - byte array to populate with random data